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3fed02069e
openssh/openssh-8.0p1-gssapi-keyex.patch
Marcus Meissner 3fed02069e Accepting request 922068 from home:hpjansson:branches:network 
- Version upgrade to 8.8p1
  * No changes for askpass, see main package changelog for
    details

- Version update to 8.8p1:
  = Security
  * sshd(8) from OpenSSH 6.2 through 8.7 failed to correctly initialise
    supplemental groups when executing an AuthorizedKeysCommand or
    AuthorizedPrincipalsCommand, where a AuthorizedKeysCommandUser or
    AuthorizedPrincipalsCommandUser directive has been set to run the
    command as a different user. Instead these commands would inherit
    the groups that sshd(8) was started with.
    Depending on system configuration, inherited groups may allow
    AuthorizedKeysCommand/AuthorizedPrincipalsCommand helper programs to
    gain unintended privilege.
    Neither AuthorizedKeysCommand nor AuthorizedPrincipalsCommand are
    enabled by default in sshd_config(5).
  = Potentially-incompatible changes
  * This release disables RSA signatures using the SHA-1 hash algorithm
    by default. This change has been made as the SHA-1 hash algorithm is
    cryptographically broken, and it is possible to create chosen-prefix
    hash collisions for <USD$50K.
    For most users, this change should be invisible and there is
    no need to replace ssh-rsa keys. OpenSSH has supported RFC8332
    RSA/SHA-256/512 signatures since release 7.2 and existing ssh-rsa keys
    will automatically use the stronger algorithm where possible.
    Incompatibility is more likely when connecting to older SSH
    implementations that have not been upgraded or have not closely tracked
    improvements in the SSH protocol. For these cases, it may be necessary
    to selectively re-enable RSA/SHA1 to allow connection and/or user
    authentication via the HostkeyAlgorithms and PubkeyAcceptedAlgorithms
    options.
  = New features
  * ssh(1): allow the ssh_config(5) CanonicalizePermittedCNAMEs
    directive to accept a "none" argument to specify the default
    behaviour.
  = Bugfixes
  * scp(1): when using the SFTP protocol, continue transferring files
    after a transfer error occurs, better matching original scp/rcp
    behaviour.
  * ssh(1): fixed a number of memory leaks in multiplexing,
  * ssh-keygen(1): avoid crash when using the -Y find-principals
    command.
  * A number of documentation and manual improvements, including
    bz#3340, PR139, PR215, PR241, PR257
- Additional changes from 8.7p1 release:
  = Potentially-incompatible changes
  * scp(1): this release changes the behaviour of remote to remote
    copies (e.g. "scp host-a:/path host-b:") to transfer through the
    local host by default. This was previously available via the -3
    flag. This mode avoids the need to expose credentials on the
    origin hop, avoids triplicate interpretation of filenames by the
    shell (by the local system, the copy origin and the destination)
    and, in conjunction with the SFTP support for scp(1) mentioned
    below, allows use of all authentication methods to the remote
    hosts (previously, only non-interactive methods could be used).
    A -R flag has been added to select the old behaviour.
  * ssh(1)/sshd(8): both the client and server are now using a
    stricter configuration file parser. The new parser uses more
    shell-like rules for quotes, space and escape characters. It is
    also more strict in rejecting configurations that include options
    lacking arguments. Previously some options (e.g. DenyUsers) could
    appear on a line with no subsequent arguments. This release will
    reject such configurations. The new parser will also reject
    configurations with unterminated quotes and multiple '='
    characters after the option name.
  * ssh(1): when using SSHFP DNS records for host key verification,
    ssh(1) will verify all matching records instead of just those
    with the specific signature type requested. This may cause host
    key verification problems if stale SSHFP records of a different
    or legacy signature type exist alongside other records for a
    particular host. bz#3322
  * ssh-keygen(1): when generating a FIDO key and specifying an
    explicit attestation challenge (using -Ochallenge), the challenge
    will now be hashed by the builtin security key middleware. This
    removes the (undocumented) requirement that challenges be exactly
    32 bytes in length and matches the expectations of libfido2.
  * sshd(8): environment="..." directives in authorized_keys files are
    now first-match-wins and limited to 1024 discrete environment
    variable names.
  = New features
  * scp(1): experimental support for transfers using the SFTP protocol
    as a replacement for the venerable SCP/RCP protocol that it has
    traditionally used. SFTP offers more predictable filename handling
    and does not require expansion of glob(3) patterns via the shell
    on the remote side.
  * sftp-server(8): add a protocol extension to support expansion of
    ~/ and ~user/ prefixed paths. This was added to support these
    paths when used by scp(1) while in SFTP mode.
  * ssh(1): add a ForkAfterAuthentication ssh_config(5) counterpart to
    the ssh(1) -f flag. GHPR231
  * ssh(1): add a StdinNull directive to ssh_config(5) that allows the
    config file to do the same thing as -n does on the ssh(1) command-
    line. GHPR231
  * ssh(1): add a SessionType directive to ssh_config, allowing the
    configuration file to offer equivalent control to the -N (no
    session) and -s (subsystem) command-line flags. GHPR231
  * ssh-keygen(1): allowed signers files used by ssh-keygen(1)
    signatures now support listing key validity intervals alongside
    they key, and ssh-keygen(1) can optionally check during signature
    verification whether a specified time falls inside this interval.
    This feature is intended for use by git to support signing and
    verifying objects using ssh keys.
  * ssh-keygen(8): support printing of the full public key in a sshsig
    signature via a -Oprint-pubkey flag.
  = Bugfixes
  * ssh(1)/sshd(8): start time-based re-keying exactly on schedule in
    the client and server mainloops. Previously the re-key timeout
    could expire but re-keying would not start until a packet was sent
    or received, causing a spin in select() if the connection was
    quiescent.
  * ssh-keygen(1): avoid Y2038 problem in printing certificate
    validity lifetimes. Dates past 2^31-1 seconds since epoch were
    displayed incorrectly on some platforms. bz#3329
  * scp(1): allow spaces to appear in usernames for local to remote
    and scp -3 remote to remote copies. bz#1164
  * ssh(1)/sshd(8): remove references to ChallengeResponseAuthentication
    in favour of KbdInteractiveAuthentication. The former is what was in
    SSHv1, the latter is what is in SSHv2 (RFC4256) and they were
    treated as somewhat but not entirely equivalent. We retain the old
    name as a deprecated alias so configuration files continue to work
    as well as a reference in the man page for people looking for it.
    bz#3303
  * ssh(1)/ssh-add(1)/ssh-keygen(1): fix decoding of X.509 subject name
    when extracting a key from a PKCS#11 certificate. bz#3327
  * ssh(1): restore blocking status on stdio fds before close. ssh(1)
    needs file descriptors in non-blocking mode to operate but it was
    not restoring the original state on exit. This could cause
    problems with fds shared with other programs via the shell,
    bz#3280 and GHPR246
  * ssh(1)/sshd(8): switch both client and server mainloops from
    select(3) to pselect(3). Avoids race conditions where a signal
    may arrive immediately before select(3) and not be processed until
    an event fires. bz#2158
  * ssh(1): sessions started with ControlPersist were incorrectly
    executing a shell when the -N (no shell) option was specified.
    bz#3290
  * ssh(1): check if IPQoS or TunnelDevice are already set before
    overriding. Prevents values in config files from overriding values
    supplied on the command line. bz#3319
  * ssh(1): fix debug message when finding a private key to match a
    certificate being attempted for user authentication. Previously it
    would print the certificate's path, whereas it was supposed to be
    showing the private key's path. GHPR247
  * sshd(8): match host certificates against host public keys, not
    private keys. Allows use of certificates with private keys held in
    a ssh-agent.  bz#3524
  * ssh(1): add a workaround for a bug in OpenSSH 7.4 sshd(8), which
    allows RSA/SHA2 signatures for public key authentication but fails
    to advertise this correctly via SSH2_MSG_EXT_INFO. This causes
    clients of these server to incorrectly match
    PubkeyAcceptedAlgorithmse and potentially refuse to offer valid
    keys. bz#3213
  * sftp(1)/scp(1): degrade gracefully if a sftp-server offers the
    limits@openssh.com extension but fails when the client tries to
    invoke it. bz#3318
  * ssh(1): allow ssh_config SetEnv to override $TERM, which is
    otherwise handled specially by the protocol. Useful in ~/.ssh/config
    to set TERM to something generic (e.g. "xterm" instead of
    "xterm-256color") for destinations that lack terminfo entries.
  * sftp-server(8): the limits@openssh.com extension was incorrectly
    marked as an operation that writes to the filesystem, which made it
    unavailable in sftp-server read-only mode. bz#3318
  * ssh(1): fix SEGV in UpdateHostkeys debug() message, triggered when
    the update removed more host keys than remain present.
  * Many manual page fixes.
- Additional changes from 8.6p1 release:
  = Security
  * sshd(8): OpenSSH 8.5 introduced the LogVerbose keyword. When this
    option was enabled with a set of patterns that activated logging
    in code that runs in the low-privilege sandboxed sshd process, the
    log messages were constructed in such a way that printf(3) format
    strings could effectively be specified the low-privilege code.
  = New features
  * sftp-server(8): add a new limits@openssh.com protocol extension
    that allows a client to discover various server limits, including
    maximum packet size and maximum read/write length.
  * sftp(1): use the new limits@openssh.com extension (when available)
    to select better transfer lengths in the client.
  * sshd(8): Add ModuliFile keyword to sshd_config to specify the
    location of the "moduli" file containing the groups for DH-GEX.
  * unit tests: Add a TEST_SSH_ELAPSED_TIMES environment variable to
    enable printing of the elapsed time in seconds of each test.
  = Bugfixes
  * ssh_config(5), sshd_config(5): sync CASignatureAlgorithms lists in
    manual pages with the current default. GHPR174
  * ssh(1): ensure that pkcs11_del_provider() is called before exit.
    GHPR234
  * ssh(1), sshd(8): fix problems in string->argv conversion. Multiple
    backslashes were not being dequoted correctly and quoted space in
    the middle of a string was being incorrectly split. GHPR223
  * ssh(1): return non-zero exit status when killed by signal; bz#3281
  * sftp-server(8): increase maximum SSH2_FXP_READ to match the maximum
    packet size. Also handle zero-length reads that are not explicitly
    banned by the spec.
- Additional changes from 8.5p1 release:
  = Security
  * ssh-agent(1): fixed a double-free memory corruption that was
    introduced in OpenSSH 8.2 . We treat all such memory faults as
    potentially exploitable. This bug could be reached by an attacker
    with access to the agent socket.
  = Potentially-incompatible changes
  * ssh(1), sshd(8): this release changes the first-preference signature
    algorithm from ECDSA to ED25519.
  * ssh(1), sshd(8): set the TOS/DSCP specified in the configuration
    for interactive use prior to TCP connect. The connection phase of
    the SSH session is time-sensitive and often explicitly interactive.
    The ultimate interactive/bulk TOS/DSCP will be set after
    authentication completes.
  * ssh(1), sshd(8): remove the pre-standardization cipher
    rijndael-cbc@lysator.liu.se. It is an alias for aes256-cbc before
    it was standardized in RFC4253 (2006), has been deprecated and
    disabled by default since OpenSSH 7.2 (2016) and was only briefly
    documented in ssh.1 in 2001.
  * ssh(1), sshd(8): update/replace the experimental post-quantum
    hybrid key exchange method based on Streamlined NTRU Prime coupled
    with X25519. The previous sntrup4591761x25519-sha512@tinyssh.org
    method is replaced with sntrup761x25519-sha512@openssh.com.
  * ssh(1): disable CheckHostIP by default. It provides insignificant
    benefits while making key rotation significantly more difficult,
    especially for hosts behind IP-based load-balancers.
  = New features
  * ssh(1): this release enables UpdateHostkeys by default subject to
    some conservative preconditions:
    - The key was matched in the UserKnownHostsFile (and not in the
      GlobalKnownHostsFile).
    - The same key does not exist under another name.
    - A certificate host key is not in use.
    - known_hosts contains no matching wildcard hostname pattern.
    - VerifyHostKeyDNS is not enabled.
    - The default UserKnownHostsFile is in use.
  * ssh(1), sshd(8): add a new LogVerbose configuration directive for
    that allows forcing maximum debug logging by file/function/line
    pattern-lists.
  * ssh(1): when prompting the user to accept a new hostkey, display
    any other host names/addresses already associated with the key.
  * ssh(1): allow UserKnownHostsFile=none to indicate that no
    known_hosts file should be used to identify host keys.
  * ssh(1): add a ssh_config KnownHostsCommand option that allows the
    client to obtain known_hosts data from a command in addition to
    the usual files.
  * ssh(1): add a ssh_config PermitRemoteOpen option that allows the
    client to restrict the destination when RemoteForward is used
    with SOCKS.
  * ssh(1): for FIDO keys, if a signature operation fails with a
    "incorrect PIN" reason and no PIN was initially requested from the
    user, then request a PIN and retry the operation. This supports
    some biometric devices that fall back to requiring PIN when reading
    of the biometric failed, and devices that require PINs for all
    hosted credentials.
  * sshd(8): implement client address-based rate-limiting via new
    sshd_config(5) PerSourceMaxStartups and PerSourceNetBlockSize
    directives that provide more fine-grained control on a per-origin
    address basis than the global MaxStartups limit.
  = Bugfixes
   * ssh(1): Prefix keyboard interactive prompts with "(user@host)" to
   make it easier to determine which connection they are associated
   with in cases like scp -3, ProxyJump, etc. bz#3224
  * sshd(8): fix sshd_config SetEnv directives located inside Match
    blocks. GHPR201
  * ssh(1): when requesting a FIDO token touch on stderr, inform the
    user once the touch has been recorded.
  * ssh(1): prevent integer overflow when ridiculously large
    ConnectTimeout values are specified, capping the effective value
    (for most platforms) at 24 days. bz#3229
  * ssh(1): consider the ECDSA key subtype when ordering host key
    algorithms in the client.
  * ssh(1), sshd(8): rename the PubkeyAcceptedKeyTypes keyword to
    PubkeyAcceptedAlgorithms. The previous name incorrectly suggested
    that it control allowed key algorithms, when this option actually
    specifies the signature algorithms that are accepted. The previous
    name remains available as an alias. bz#3253
  * ssh(1), sshd(8): similarly, rename HostbasedKeyTypes (ssh) and
    HostbasedAcceptedKeyTypes (sshd) to HostbasedAcceptedAlgorithms.
  * sftp-server(8): add missing lsetstat@openssh.com documentation
    and advertisement in the server's SSH2_FXP_VERSION hello packet.
  * ssh(1), sshd(8): more strictly enforce KEX state-machine by
    banning packet types once they are received. Fixes memleak caused
    by duplicate SSH2_MSG_KEX_DH_GEX_REQUEST (oss-fuzz #30078).
  * sftp(1): allow the full range of UIDs/GIDs for chown/chgrp on 32bit
    platforms instead of being limited by LONG_MAX. bz#3206
  * Minor man page fixes (capitalization, commas, etc.) bz#3223
  * sftp(1): when doing an sftp recursive upload or download of a
    read-only directory, ensure that the directory is created with
    write and execute permissions in the interim so that the transfer
    can actually complete, then set the directory permission as the
    final step. bz#3222
  * ssh-keygen(1): document the -Z, check the validity of its argument
    earlier and provide a better error message if it's not correct.
    bz#2879
  * ssh(1): ignore comments at the end of config lines in ssh_config,
    similar to what we already do for sshd_config. bz#2320
  * sshd_config(5): mention that DisableForwarding is valid in a
    sshd_config Match block. bz3239
  * sftp(1): fix incorrect sorting of "ls -ltr" under some
    circumstances. bz3248.
  * ssh(1), sshd(8): fix potential integer truncation of (unlikely)
    timeout values. bz#3250
  * ssh(1): make hostbased authentication send the signature algorithm
    in its SSH2_MSG_USERAUTH_REQUEST packets instead of the key type.
    This make HostbasedAcceptedAlgorithms do what it is supposed to -
    filter on signature algorithm and not key type.
- Rebased patches:
  * openssh-7.7p1-IPv6_X_forwarding.patch
  * openssh-7.7p1-X11_trusted_forwarding.patch
  * openssh-7.7p1-X_forward_with_disabled_ipv6.patch
  * openssh-7.7p1-cavstest-ctr.patch
  * openssh-7.7p1-cavstest-kdf.patch
  * openssh-7.7p1-disable_openssl_abi_check.patch
  * openssh-7.7p1-eal3.patch
  * openssh-7.7p1-enable_PAM_by_default.patch
  * openssh-7.7p1-fips.patch
  * openssh-7.7p1-fips_checks.patch
  * openssh-7.7p1-host_ident.patch
  * openssh-7.7p1-hostname_changes_when_forwarding_X.patch
  * openssh-7.7p1-ldap.patch
  * openssh-7.7p1-no_fork-no_pid_file.patch
  * openssh-7.7p1-pam_check_locks.patch
  * openssh-7.7p1-pts_names_formatting.patch
  * openssh-7.7p1-remove_xauth_cookies_on_exit.patch
  * openssh-7.7p1-seccomp_ipc_flock.patch
  * openssh-7.7p1-seccomp_stat.patch
  * openssh-7.7p1-send_locale.patch
  * openssh-7.7p1-sftp_force_permissions.patch
  * openssh-7.7p1-sftp_print_diagnostic_messages.patch
  * openssh-7.7p1-systemd-notify.patch
  * openssh-7.9p1-keygen-preserve-perms.patch
  * openssh-7.9p1-revert-new-qos-defaults.patch
  * openssh-8.0p1-gssapi-keyex.patch
  * openssh-8.1p1-audit.patch
  * openssh-8.1p1-seccomp-clock_gettime64.patch
  * openssh-8.1p1-seccomp-clock_nanosleep.patch
  * openssh-8.1p1-seccomp-clock_nanosleep_time64.patch
  * openssh-8.1p1-use-openssl-kdf.patch
  * openssh-8.4p1-vendordir.patch
  * openssh-fips-ensure-approved-moduli.patch
  * openssh-link-with-sk.patch
  * openssh-reenable-dh-group14-sha1-default.patch
  * openssh-whitelist-syscalls.patch
- Removed openssh-fix-ssh-copy-id.patch (fixed upstream).

OBS-URL: https://build.opensuse.org/request/show/922068
OBS-URL: https://build.opensuse.org/package/show/network/openssh?expand=0&rev=235
2021-10-07 08:06:58 +00:00

3916 lines
121 KiB
Diff
Raw Blame History

Index: openssh-8.8p1/Makefile.in
===================================================================
--- openssh-8.8p1.orig/Makefile.in
+++ openssh-8.8p1/Makefile.in
@@ -112,6 +112,7 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \
kex.o kexdh.o kexgex.o kexecdh.o kexc25519.o \
kexgexc.o kexgexs.o \
kexsntrup761x25519.o sntrup761.o kexgen.o \
+ kexgssc.o \
sftp-realpath.o platform-pledge.o platform-tracing.o platform-misc.o \
sshbuf-io.o
@@ -130,7 +131,7 @@ SSHDOBJS=sshd.o auth-rhosts.o auth-passw
auth-bsdauth.o auth2-hostbased.o auth2-kbdint.o \
auth2-none.o auth2-passwd.o auth2-pubkey.o \
monitor.o monitor_wrap.o auth-krb5.o \
- auth2-gss.o gss-serv.o gss-serv-krb5.o \
+ auth2-gss.o gss-serv.o gss-serv-krb5.o kexgsss.o \
loginrec.o auth-pam.o auth-shadow.o auth-sia.o md5crypt.o \
srclimit.o sftp-server.o sftp-common.o \
sandbox-null.o sandbox-rlimit.o sandbox-systrace.o sandbox-darwin.o \
Index: openssh-8.8p1/auth.c
===================================================================
--- openssh-8.8p1.orig/auth.c
+++ openssh-8.8p1/auth.c
@@ -402,7 +402,8 @@ auth_root_allowed(struct ssh *ssh, const
case PERMIT_NO_PASSWD:
if (strcmp(method, "publickey") == 0 ||
strcmp(method, "hostbased") == 0 ||
- strcmp(method, "gssapi-with-mic") == 0)
+ strcmp(method, "gssapi-with-mic") == 0 ||
+ strcmp(method, "gssapi-keyex") == 0)
return 1;
break;
case PERMIT_FORCED_ONLY:
@@ -730,97 +731,6 @@ fakepw(void)
}
/*
- * Returns the remote DNS hostname as a string. The returned string must not
- * be freed. NB. this will usually trigger a DNS query the first time it is
- * called.
- * This function does additional checks on the hostname to mitigate some
- * attacks on based on conflation of hostnames and IP addresses.
- */
-
-static char *
-remote_hostname(struct ssh *ssh)
-{
- struct sockaddr_storage from;
- socklen_t fromlen;
- struct addrinfo hints, *ai, *aitop;
- char name[NI_MAXHOST], ntop2[NI_MAXHOST];
- const char *ntop = ssh_remote_ipaddr(ssh);
-
- /* Get IP address of client. */
- fromlen = sizeof(from);
- memset(&from, 0, sizeof(from));
- if (getpeername(ssh_packet_get_connection_in(ssh),
- (struct sockaddr *)&from, &fromlen) == -1) {
- debug("getpeername failed: %.100s", strerror(errno));
- return xstrdup(ntop);
- }
-
- ipv64_normalise_mapped(&from, &fromlen);
- if (from.ss_family == AF_INET6)
- fromlen = sizeof(struct sockaddr_in6);
-
- debug3("Trying to reverse map address %.100s.", ntop);
- /* Map the IP address to a host name. */
- if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name),
- NULL, 0, NI_NAMEREQD) != 0) {
- /* Host name not found. Use ip address. */
- return xstrdup(ntop);
- }
-
- /*
- * if reverse lookup result looks like a numeric hostname,
- * someone is trying to trick us by PTR record like following:
- * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5
- */
- memset(&hints, 0, sizeof(hints));
- hints.ai_socktype = SOCK_DGRAM; /*dummy*/
- hints.ai_flags = AI_NUMERICHOST;
- if (getaddrinfo(name, NULL, &hints, &ai) == 0) {
- logit("Nasty PTR record \"%s\" is set up for %s, ignoring",
- name, ntop);
- freeaddrinfo(ai);
- return xstrdup(ntop);
- }
-
- /* Names are stored in lowercase. */
- lowercase(name);
-
- /*
- * Map it back to an IP address and check that the given
- * address actually is an address of this host. This is
- * necessary because anyone with access to a name server can
- * define arbitrary names for an IP address. Mapping from
- * name to IP address can be trusted better (but can still be
- * fooled if the intruder has access to the name server of
- * the domain).
- */
- memset(&hints, 0, sizeof(hints));
- hints.ai_family = from.ss_family;
- hints.ai_socktype = SOCK_STREAM;
- if (getaddrinfo(name, NULL, &hints, &aitop) != 0) {
- logit("reverse mapping checking getaddrinfo for %.700s "
- "[%s] failed.", name, ntop);
- return xstrdup(ntop);
- }
- /* Look for the address from the list of addresses. */
- for (ai = aitop; ai; ai = ai->ai_next) {
- if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2,
- sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 &&
- (strcmp(ntop, ntop2) == 0))
- break;
- }
- freeaddrinfo(aitop);
- /* If we reached the end of the list, the address was not there. */
- if (ai == NULL) {
- /* Address not found for the host name. */
- logit("Address %.100s maps to %.600s, but this does not "
- "map back to the address.", ntop, name);
- return xstrdup(ntop);
- }
- return xstrdup(name);
-}
-
-/*
* Return the canonical name of the host in the other side of the current
* connection. The host name is cached, so it is efficient to call this
* several times.
Index: openssh-8.8p1/auth2-gss.c
===================================================================
--- openssh-8.8p1.orig/auth2-gss.c
+++ openssh-8.8p1/auth2-gss.c
@@ -1,7 +1,7 @@
/* $OpenBSD: auth2-gss.c,v 1.32 2021/01/27 10:15:08 djm Exp $ */
/*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -56,6 +56,48 @@ static int input_gssapi_exchange_complet
static int input_gssapi_errtok(int, u_int32_t, struct ssh *);
/*
+ * The 'gssapi_keyex' userauth mechanism.
+ */
+static int
+userauth_gsskeyex(struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ int r, authenticated = 0;
+ struct sshbuf *b = NULL;
+ gss_buffer_desc mic, gssbuf;
+ u_char *p;
+ size_t len;
+
+ if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("%s: %s", __func__, ssh_err(r));
+
+ if ((b = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+
+ mic.value = p;
+ mic.length = len;
+
+ ssh_gssapi_buildmic(b, authctxt->user, authctxt->service,
+ "gssapi-keyex", ssh->kex->session_id);
+
+ if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
+ fatal("%s: sshbuf_mutable_ptr failed", __func__);
+ gssbuf.length = sshbuf_len(b);
+
+ /* gss_kex_context is NULL with privsep, so we can't check it here */
+ if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context,
+ &gssbuf, &mic))))
+ authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
+ authctxt->pw, 1));
+
+ sshbuf_free(b);
+ free(mic.value);
+
+ return (authenticated);
+}
+
+/*
* We only support those mechanisms that we know about (ie ones that we know
* how to check local user kuserok and the like)
*/
@@ -261,7 +303,8 @@ input_gssapi_exchange_complete(int type,
if ((r = sshpkt_get_end(ssh)) != 0)
fatal_fr(r, "parse packet");
- authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
+ authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
+ authctxt->pw, 1));
if ((!use_privsep || mm_is_monitor()) &&
(displayname = ssh_gssapi_displayname()) != NULL)
@@ -307,7 +350,8 @@ input_gssapi_mic(int type, u_int32_t ple
gssbuf.length = sshbuf_len(b);
if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
- authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
+ authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
+ authctxt->pw, 0));
else
logit("GSSAPI MIC check failed");
@@ -327,6 +371,12 @@ input_gssapi_mic(int type, u_int32_t ple
return 0;
}
+Authmethod method_gsskeyex = {
+ "gssapi-keyex",
+ userauth_gsskeyex,
+ &options.gss_authentication
+};
+
Authmethod method_gssapi = {
"gssapi-with-mic",
userauth_gssapi,
Index: openssh-8.8p1/auth2.c
===================================================================
--- openssh-8.8p1.orig/auth2.c
+++ openssh-8.8p1/auth2.c
@@ -71,6 +71,7 @@ extern Authmethod method_passwd;
extern Authmethod method_kbdint;
extern Authmethod method_hostbased;
#ifdef GSSAPI
+extern Authmethod method_gsskeyex;
extern Authmethod method_gssapi;
#endif
@@ -78,6 +79,7 @@ Authmethod *authmethods[] = {
&method_none,
&method_pubkey,
#ifdef GSSAPI
+ &method_gsskeyex,
&method_gssapi,
#endif
&method_passwd,
Index: openssh-8.8p1/canohost.c
===================================================================
--- openssh-8.8p1.orig/canohost.c
+++ openssh-8.8p1/canohost.c
@@ -35,6 +35,99 @@
#include "canohost.h"
#include "misc.h"
+/*
+ * Returns the remote DNS hostname as a string. The returned string must not
+ * be freed. NB. this will usually trigger a DNS query the first time it is
+ * called.
+ * This function does additional checks on the hostname to mitigate some
+ * attacks on legacy rhosts-style authentication.
+ * XXX is RhostsRSAAuthentication vulnerable to these?
+ * XXX Can we remove these checks? (or if not, remove RhostsRSAAuthentication?)
+ */
+
+char *
+remote_hostname(struct ssh *ssh)
+{
+ struct sockaddr_storage from;
+ socklen_t fromlen;
+ struct addrinfo hints, *ai, *aitop;
+ char name[NI_MAXHOST], ntop2[NI_MAXHOST];
+ const char *ntop = ssh_remote_ipaddr(ssh);
+
+ /* Get IP address of client. */
+ fromlen = sizeof(from);
+ memset(&from, 0, sizeof(from));
+ if (getpeername(ssh_packet_get_connection_in(ssh),
+ (struct sockaddr *)&from, &fromlen) == -1) {
+ debug("getpeername failed: %.100s", strerror(errno));
+ return xstrdup(ntop);
+ }
+
+ ipv64_normalise_mapped(&from, &fromlen);
+ if (from.ss_family == AF_INET6)
+ fromlen = sizeof(struct sockaddr_in6);
+
+ debug3("Trying to reverse map address %.100s.", ntop);
+ /* Map the IP address to a host name. */
+ if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name),
+ NULL, 0, NI_NAMEREQD) != 0) {
+ /* Host name not found. Use ip address. */
+ return xstrdup(ntop);
+ }
+
+ /*
+ * if reverse lookup result looks like a numeric hostname,
+ * someone is trying to trick us by PTR record like following:
+ * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5
+ */
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_socktype = SOCK_DGRAM; /*dummy*/
+ hints.ai_flags = AI_NUMERICHOST;
+ if (getaddrinfo(name, NULL, &hints, &ai) == 0) {
+ logit("Nasty PTR record \"%s\" is set up for %s, ignoring",
+ name, ntop);
+ freeaddrinfo(ai);
+ return xstrdup(ntop);
+ }
+
+ /* Names are stored in lowercase. */
+ lowercase(name);
+
+ /*
+ * Map it back to an IP address and check that the given
+ * address actually is an address of this host. This is
+ * necessary because anyone with access to a name server can
+ * define arbitrary names for an IP address. Mapping from
+ * name to IP address can be trusted better (but can still be
+ * fooled if the intruder has access to the name server of
+ * the domain).
+ */
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = from.ss_family;
+ hints.ai_socktype = SOCK_STREAM;
+ if (getaddrinfo(name, NULL, &hints, &aitop) != 0) {
+ logit("reverse mapping checking getaddrinfo for %.700s "
+ "[%s] failed.", name, ntop);
+ return xstrdup(ntop);
+ }
+ /* Look for the address from the list of addresses. */
+ for (ai = aitop; ai; ai = ai->ai_next) {
+ if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2,
+ sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 &&
+ (strcmp(ntop, ntop2) == 0))
+ break;
+ }
+ freeaddrinfo(aitop);
+ /* If we reached the end of the list, the address was not there. */
+ if (ai == NULL) {
+ /* Address not found for the host name. */
+ logit("Address %.100s maps to %.600s, but this does not "
+ "map back to the address.", ntop, name);
+ return xstrdup(ntop);
+ }
+ return xstrdup(name);
+}
+
void
ipv64_normalise_mapped(struct sockaddr_storage *addr, socklen_t *len)
{
Index: openssh-8.8p1/canohost.h
===================================================================
--- openssh-8.8p1.orig/canohost.h
+++ openssh-8.8p1/canohost.h
@@ -15,6 +15,9 @@
#ifndef _CANOHOST_H
#define _CANOHOST_H
+struct ssh;
+
+char *remote_hostname(struct ssh *);
char *get_peer_ipaddr(int);
int get_peer_port(int);
char *get_local_ipaddr(int);
Index: openssh-8.8p1/clientloop.c
===================================================================
--- openssh-8.8p1.orig/clientloop.c
+++ openssh-8.8p1/clientloop.c
@@ -112,6 +112,10 @@
#include "ssherr.h"
#include "hostfile.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
/* import options */
extern Options options;
@@ -1343,9 +1347,18 @@ client_loop(struct ssh *ssh, int have_pt
break;
/* Do channel operations unless rekeying in progress. */
- if (!ssh_packet_is_rekeying(ssh))
+ if (!ssh_packet_is_rekeying(ssh)) {
channel_after_select(ssh, readset, writeset);
+#ifdef GSSAPI
+ if (options.gss_renewal_rekey &&
+ ssh_gssapi_credentials_updated(NULL)) {
+ debug("credentials updated - forcing rekey");
+ need_rekeying = 1;
+ }
+#endif
+ }
+
/* Buffer input from the connection. */
client_process_net_input(ssh, readset);
Index: openssh-8.8p1/configure.ac
===================================================================
--- openssh-8.8p1.orig/configure.ac
+++ openssh-8.8p1/configure.ac
@@ -709,6 +709,30 @@ main() { if (NSVersionOfRunTimeLibrary("
[Use tunnel device compatibility to OpenBSD])
AC_DEFINE([SSH_TUN_PREPEND_AF], [1],
[Prepend the address family to IP tunnel traffic])
+ AC_MSG_CHECKING([if we have the Security Authorization Session API])
+ AC_TRY_COMPILE([#include <Security/AuthSession.h>],
+ [SessionCreate(0, 0);],
+ [ac_cv_use_security_session_api="yes"
+ AC_DEFINE([USE_SECURITY_SESSION_API], [1],
+ [platform has the Security Authorization Session API])
+ LIBS="$LIBS -framework Security"
+ AC_MSG_RESULT([yes])],
+ [ac_cv_use_security_session_api="no"
+ AC_MSG_RESULT([no])])
+ AC_MSG_CHECKING([if we have an in-memory credentials cache])
+ AC_TRY_COMPILE(
+ [#include <Kerberos/Kerberos.h>],
+ [cc_context_t c;
+ (void) cc_initialize (&c, 0, NULL, NULL);],
+ [AC_DEFINE([USE_CCAPI], [1],
+ [platform uses an in-memory credentials cache])
+ LIBS="$LIBS -framework Security"
+ AC_MSG_RESULT([yes])
+ if test "x$ac_cv_use_security_session_api" = "xno"; then
+ AC_MSG_ERROR([*** Need a security framework to use the credentials cache API ***])
+ fi],
+ [AC_MSG_RESULT([no])]
+ )
m4_pattern_allow([AU_IPv])
AC_CHECK_DECL([AU_IPv4], [],
AC_DEFINE([AU_IPv4], [0], [System only supports IPv4 audit records])
Index: openssh-8.8p1/gss-genr.c
===================================================================
--- openssh-8.8p1.orig/gss-genr.c
+++ openssh-8.8p1/gss-genr.c
@@ -1,7 +1,7 @@
/* $OpenBSD: gss-genr.c,v 1.28 2021/01/27 10:05:28 djm Exp $ */
/*
- * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -42,8 +42,34 @@
#include "log.h"
#include "ssh2.h"
+#include "cipher.h"
+#include "sshkey.h"
+#include "kex.h"
+#include "digest.h"
+#include "packet.h"
+
#include "ssh-gss.h"
+typedef struct {
+ char *encoded;
+ gss_OID oid;
+} ssh_gss_kex_mapping;
+
+/*
+ * XXX - It would be nice to find a more elegant way of handling the
+ * XXX passing of the key exchange context to the userauth routines
+ */
+
+Gssctxt *gss_kex_context = NULL;
+
+static ssh_gss_kex_mapping *gss_enc2oid = NULL;
+
+int
+ssh_gssapi_oid_table_ok(void)
+{
+ return (gss_enc2oid != NULL);
+}
+
/* sshbuf_get for gss_buffer_desc */
int
ssh_gssapi_get_buffer_desc(struct sshbuf *b, gss_buffer_desc *g)
@@ -59,6 +85,161 @@ ssh_gssapi_get_buffer_desc(struct sshbuf
return 0;
}
+/* sshpkt_get of gss_buffer_desc */
+int
+ssh_gssapi_sshpkt_get_buffer_desc(struct ssh *ssh, gss_buffer_desc *g)
+{
+ int r;
+ u_char *p;
+ size_t len;
+
+ if ((r = sshpkt_get_string(ssh, &p, &len)) != 0)
+ return r;
+ g->value = p;
+ g->length = len;
+ return 0;
+}
+
+/*
+ * Return a list of the gss-group1-sha1 mechanisms supported by this program
+ *
+ * We test mechanisms to ensure that we can use them, to avoid starting
+ * a key exchange with a bad mechanism
+ */
+
+char *
+ssh_gssapi_client_mechanisms(const char *host, const char *client,
+ const char *kex) {
+ gss_OID_set gss_supported = NULL;
+ OM_uint32 min_status;
+
+ if (GSS_ERROR(gss_indicate_mechs(&min_status, &gss_supported)))
+ return NULL;
+
+ return ssh_gssapi_kex_mechs(gss_supported, ssh_gssapi_check_mechanism,
+ host, client, kex);
+}
+
+char *
+ssh_gssapi_kex_mechs(gss_OID_set gss_supported, ssh_gssapi_check_fn *check,
+ const char *host, const char *client, const char *kex) {
+ struct sshbuf *buf = NULL;
+ size_t i;
+ int r, oidpos, enclen;
+ char *mechs, *encoded;
+ u_char digest[SSH_DIGEST_MAX_LENGTH];
+ char deroid[2];
+ struct ssh_digest_ctx *md = NULL;
+ char *s, *cp, *p;
+
+ if (gss_enc2oid != NULL) {
+ for (i = 0; gss_enc2oid[i].encoded != NULL; i++)
+ free(gss_enc2oid[i].encoded);
+ free(gss_enc2oid);
+ }
+
+ gss_enc2oid = xmalloc(sizeof(ssh_gss_kex_mapping) *
+ (gss_supported->count + 1));
+
+ if ((buf = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+
+ oidpos = 0;
+ s = cp = xstrdup(kex);
+ for (i = 0; i < gss_supported->count; i++) {
+ if (gss_supported->elements[i].length < 128 &&
+ (*check)(NULL, &(gss_supported->elements[i]), host, client)) {
+
+ deroid[0] = SSH_GSS_OIDTYPE;
+ deroid[1] = gss_supported->elements[i].length;
+
+ if ((md = ssh_digest_start(SSH_DIGEST_MD5)) == NULL ||
+ (r = ssh_digest_update(md, deroid, 2)) != 0 ||
+ (r = ssh_digest_update(md,
+ gss_supported->elements[i].elements,
+ gss_supported->elements[i].length)) != 0 ||
+ (r = ssh_digest_final(md, digest, sizeof(digest))) != 0)
+ fatal("%s: digest failed: %s", __func__,
+ ssh_err(r));
+ ssh_digest_free(md);
+ md = NULL;
+
+ encoded = xmalloc(ssh_digest_bytes(SSH_DIGEST_MD5)
+ * 2);
+ enclen = __b64_ntop(digest,
+ ssh_digest_bytes(SSH_DIGEST_MD5), encoded,
+ ssh_digest_bytes(SSH_DIGEST_MD5) * 2);
+
+ cp = strncpy(s, kex, strlen(kex));
+ for ((p = strsep(&cp, ",")); p && *p != '\0';
+ (p = strsep(&cp, ","))) {
+ if (sshbuf_len(buf) != 0 &&
+ (r = sshbuf_put_u8(buf, ',')) != 0)
+ fatal("%s: sshbuf_put_u8 error: %s",
+ __func__, ssh_err(r));
+ if ((r = sshbuf_put(buf, p, strlen(p))) != 0 ||
+ (r = sshbuf_put(buf, encoded, enclen)) != 0)
+ fatal("%s: sshbuf_put error: %s",
+ __func__, ssh_err(r));
+ }
+
+ gss_enc2oid[oidpos].oid = &(gss_supported->elements[i]);
+ gss_enc2oid[oidpos].encoded = encoded;
+ oidpos++;
+ }
+ }
+ free(s);
+ gss_enc2oid[oidpos].oid = NULL;
+ gss_enc2oid[oidpos].encoded = NULL;
+
+ if ((mechs = sshbuf_dup_string(buf)) == NULL)
+ fatal("%s: sshbuf_dup_string failed", __func__);
+
+ sshbuf_free(buf);
+
+ if (strlen(mechs) == 0) {
+ free(mechs);
+ mechs = NULL;
+ }
+
+ return (mechs);
+}
+
+gss_OID
+ssh_gssapi_id_kex(Gssctxt *ctx, char *name, int kex_type) {
+ int i = 0;
+
+#define SKIP_KEX_NAME(type) \
+ case type: \
+ if (strlen(name) < sizeof(type##_ID)) \
+ return GSS_C_NO_OID; \
+ name += sizeof(type##_ID) - 1; \
+ break;
+
+ switch (kex_type) {
+ SKIP_KEX_NAME(KEX_GSS_GRP1_SHA1)
+ SKIP_KEX_NAME(KEX_GSS_GRP14_SHA1)
+ SKIP_KEX_NAME(KEX_GSS_GRP14_SHA256)
+ SKIP_KEX_NAME(KEX_GSS_GRP16_SHA512)
+ SKIP_KEX_NAME(KEX_GSS_GEX_SHA1)
+ SKIP_KEX_NAME(KEX_GSS_NISTP256_SHA256)
+ SKIP_KEX_NAME(KEX_GSS_C25519_SHA256)
+ default:
+ return GSS_C_NO_OID;
+ }
+
+#undef SKIP_KEX_NAME
+
+ while (gss_enc2oid[i].encoded != NULL &&
+ strcmp(name, gss_enc2oid[i].encoded) != 0)
+ i++;
+
+ if (gss_enc2oid[i].oid != NULL && ctx != NULL)
+ ssh_gssapi_set_oid(ctx, gss_enc2oid[i].oid);
+
+ return gss_enc2oid[i].oid;
+}
+
/* Check that the OID in a data stream matches that in the context */
int
ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
@@ -215,7 +396,7 @@ ssh_gssapi_init_ctx(Gssctxt *ctx, int de
}
ctx->major = gss_init_sec_context(&ctx->minor,
- GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
+ ctx->client_creds, &ctx->context, ctx->name, ctx->oid,
GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
0, NULL, recv_tok, NULL, send_tok, flags, NULL);
@@ -245,8 +426,42 @@ ssh_gssapi_import_name(Gssctxt *ctx, con
}
OM_uint32
+ssh_gssapi_client_identity(Gssctxt *ctx, const char *name)
+{
+ gss_buffer_desc gssbuf;
+ gss_name_t gssname;
+ OM_uint32 status;
+ gss_OID_set oidset;
+
+ gssbuf.value = (void *) name;
+ gssbuf.length = strlen(gssbuf.value);
+
+ gss_create_empty_oid_set(&status, &oidset);
+ gss_add_oid_set_member(&status, ctx->oid, &oidset);
+
+ ctx->major = gss_import_name(&ctx->minor, &gssbuf,
+ GSS_C_NT_USER_NAME, &gssname);
+
+ if (!ctx->major)
+ ctx->major = gss_acquire_cred(&ctx->minor,
+ gssname, 0, oidset, GSS_C_INITIATE,
+ &ctx->client_creds, NULL, NULL);
+
+ gss_release_name(&status, &gssname);
+ gss_release_oid_set(&status, &oidset);
+
+ if (ctx->major)
+ ssh_gssapi_error(ctx);
+
+ return(ctx->major);
+}
+
+OM_uint32
ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
{
+ if (ctx == NULL)
+ return -1;
+
if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
GSS_C_QOP_DEFAULT, buffer, hash)))
ssh_gssapi_error(ctx);
@@ -254,6 +469,19 @@ ssh_gssapi_sign(Gssctxt *ctx, gss_buffer
return (ctx->major);
}
+/* Priviledged when used by server */
+OM_uint32
+ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
+{
+ if (ctx == NULL)
+ return -1;
+
+ ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
+ gssbuf, gssmic, NULL);
+
+ return (ctx->major);
+}
+
void
ssh_gssapi_buildmic(struct sshbuf *b, const char *user, const char *service,
const char *context, const struct sshbuf *session_id)
@@ -270,11 +498,16 @@ ssh_gssapi_buildmic(struct sshbuf *b, co
}
int
-ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
+ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host,
+ const char *client)
{
gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
OM_uint32 major, minor;
gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"};
+ Gssctxt *intctx = NULL;
+
+ if (ctx == NULL)
+ ctx = &intctx;
/* RFC 4462 says we MUST NOT do SPNEGO */
if (oid->length == spnego_oid.length &&
@@ -284,6 +517,10 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx
ssh_gssapi_build_ctx(ctx);
ssh_gssapi_set_oid(*ctx, oid);
major = ssh_gssapi_import_name(*ctx, host);
+
+ if (!GSS_ERROR(major) && client)
+ major = ssh_gssapi_client_identity(*ctx, client);
+
if (!GSS_ERROR(major)) {
major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token,
NULL);
@@ -293,10 +530,66 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx
GSS_C_NO_BUFFER);
}
- if (GSS_ERROR(major))
+ if (GSS_ERROR(major) || intctx != NULL)
ssh_gssapi_delete_ctx(ctx);
return (!GSS_ERROR(major));
}
+int
+ssh_gssapi_credentials_updated(Gssctxt *ctxt) {
+ static gss_name_t saved_name = GSS_C_NO_NAME;
+ static OM_uint32 saved_lifetime = 0;
+ static gss_OID saved_mech = GSS_C_NO_OID;
+ static gss_name_t name;
+ static OM_uint32 last_call = 0;
+ OM_uint32 lifetime, now, major, minor;
+ int equal;
+
+ now = time(NULL);
+
+ if (ctxt) {
+ debug("Rekey has happened - updating saved versions");
+
+ if (saved_name != GSS_C_NO_NAME)
+ gss_release_name(&minor, &saved_name);
+
+ major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
+ &saved_name, &saved_lifetime, NULL, NULL);
+
+ if (!GSS_ERROR(major)) {
+ saved_mech = ctxt->oid;
+ saved_lifetime+= now;
+ } else {
+ /* Handle the error */
+ }
+ return 0;
+ }
+
+ if (now - last_call < 10)
+ return 0;
+
+ last_call = now;
+
+ if (saved_mech == GSS_C_NO_OID)
+ return 0;
+
+ major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
+ &name, &lifetime, NULL, NULL);
+ if (major == GSS_S_CREDENTIALS_EXPIRED)
+ return 0;
+ else if (GSS_ERROR(major))
+ return 0;
+
+ major = gss_compare_name(&minor, saved_name, name, &equal);
+ gss_release_name(&minor, &name);
+ if (GSS_ERROR(major))
+ return 0;
+
+ if (equal && (saved_lifetime < lifetime + now - 10))
+ return 1;
+
+ return 0;
+}
+
#endif /* GSSAPI */
Index: openssh-8.8p1/gss-serv-krb5.c
===================================================================
--- openssh-8.8p1.orig/gss-serv-krb5.c
+++ openssh-8.8p1/gss-serv-krb5.c
@@ -1,7 +1,7 @@
/* $OpenBSD: gss-serv-krb5.c,v 1.9 2018/07/09 21:37:55 markus Exp $ */
/*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -120,7 +120,7 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl
krb5_error_code problem;
krb5_principal princ;
OM_uint32 maj_status, min_status;
- int len;
+ const char *new_ccname, *new_cctype;
const char *errmsg;
if (client->creds == NULL) {
@@ -180,11 +180,26 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl
return;
}
- client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache));
+ new_cctype = krb5_cc_get_type(krb_context, ccache);
+ new_ccname = krb5_cc_get_name(krb_context, ccache);
+
client->store.envvar = "KRB5CCNAME";
- len = strlen(client->store.filename) + 6;
- client->store.envval = xmalloc(len);
- snprintf(client->store.envval, len, "FILE:%s", client->store.filename);
+#ifdef USE_CCAPI
+ xasprintf(&client->store.envval, "API:%s", new_ccname);
+ client->store.filename = NULL;
+#else
+ if (new_ccname[0] == ':')
+ new_ccname++;
+ xasprintf(&client->store.envval, "%s:%s", new_cctype, new_ccname);
+ if (strcmp(new_cctype, "DIR") == 0) {
+ char *p;
+ p = strrchr(client->store.envval, '/');
+ if (p)
+ *p = '\0';
+ }
+ if ((strcmp(new_cctype, "FILE") == 0) || (strcmp(new_cctype, "DIR") == 0))
+ client->store.filename = xstrdup(new_ccname);
+#endif
#ifdef USE_PAM
if (options.use_pam)
@@ -193,9 +208,76 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl
krb5_cc_close(krb_context, ccache);
+ client->store.data = krb_context;
+
return;
}
+int
+ssh_gssapi_krb5_updatecreds(ssh_gssapi_ccache *store,
+ ssh_gssapi_client *client)
+{
+ krb5_ccache ccache = NULL;
+ krb5_principal principal = NULL;
+ char *name = NULL;
+ krb5_error_code problem;
+ OM_uint32 maj_status, min_status;
+
+ if ((problem = krb5_cc_resolve(krb_context, store->envval, &ccache))) {
+ logit("krb5_cc_resolve(): %.100s",
+ krb5_get_err_text(krb_context, problem));
+ return 0;
+ }
+
+ /* Find out who the principal in this cache is */
+ if ((problem = krb5_cc_get_principal(krb_context, ccache,
+ &principal))) {
+ logit("krb5_cc_get_principal(): %.100s",
+ krb5_get_err_text(krb_context, problem));
+ krb5_cc_close(krb_context, ccache);
+ return 0;
+ }
+
+ if ((problem = krb5_unparse_name(krb_context, principal, &name))) {
+ logit("krb5_unparse_name(): %.100s",
+ krb5_get_err_text(krb_context, problem));
+ krb5_free_principal(krb_context, principal);
+ krb5_cc_close(krb_context, ccache);
+ return 0;
+ }
+
+
+ if (strcmp(name,client->exportedname.value)!=0) {
+ debug("Name in local credentials cache differs. Not storing");
+ krb5_free_principal(krb_context, principal);
+ krb5_cc_close(krb_context, ccache);
+ krb5_free_unparsed_name(krb_context, name);
+ return 0;
+ }
+ krb5_free_unparsed_name(krb_context, name);
+
+ /* Name matches, so lets get on with it! */
+
+ if ((problem = krb5_cc_initialize(krb_context, ccache, principal))) {
+ logit("krb5_cc_initialize(): %.100s",
+ krb5_get_err_text(krb_context, problem));
+ krb5_free_principal(krb_context, principal);
+ krb5_cc_close(krb_context, ccache);
+ return 0;
+ }
+
+ krb5_free_principal(krb_context, principal);
+
+ if ((maj_status = gss_krb5_copy_ccache(&min_status, client->creds,
+ ccache))) {
+ logit("gss_krb5_copy_ccache() failed. Sorry!");
+ krb5_cc_close(krb_context, ccache);
+ return 0;
+ }
+
+ return 1;
+}
+
ssh_gssapi_mech gssapi_kerberos_mech = {
"toWM5Slw5Ew8Mqkay+al2g==",
"Kerberos",
@@ -203,7 +285,8 @@ ssh_gssapi_mech gssapi_kerberos_mech = {
NULL,
&ssh_gssapi_krb5_userok,
NULL,
- &ssh_gssapi_krb5_storecreds
+ &ssh_gssapi_krb5_storecreds,
+ &ssh_gssapi_krb5_updatecreds
};
#endif /* KRB5 */
Index: openssh-8.8p1/gss-serv.c
===================================================================
--- openssh-8.8p1.orig/gss-serv.c
+++ openssh-8.8p1/gss-serv.c
@@ -1,7 +1,7 @@
/* $OpenBSD: gss-serv.c,v 1.32 2020/03/13 03:17:07 djm Exp $ */
/*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -44,17 +44,19 @@
#include "session.h"
#include "misc.h"
#include "servconf.h"
+#include "uidswap.h"
#include "ssh-gss.h"
+#include "monitor_wrap.h"
extern ServerOptions options;
static ssh_gssapi_client gssapi_client =
- { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER,
- GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL, NULL}};
+ { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER, GSS_C_NO_CREDENTIAL,
+ GSS_C_NO_NAME, NULL, {NULL, NULL, NULL, NULL, NULL}, 0, 0};
ssh_gssapi_mech gssapi_null_mech =
- { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL};
+ { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL, NULL};
#ifdef KRB5
extern ssh_gssapi_mech gssapi_kerberos_mech;
@@ -141,6 +143,29 @@ ssh_gssapi_server_ctx(Gssctxt **ctx, gss
}
/* Unprivileged */
+char *
+ssh_gssapi_server_mechanisms(void) {
+ if (supported_oids == NULL)
+ ssh_gssapi_prepare_supported_oids();
+ return (ssh_gssapi_kex_mechs(supported_oids,
+ &ssh_gssapi_server_check_mech, NULL, NULL,
+ options.gss_kex_algorithms));
+}
+
+/* Unprivileged */
+int
+ssh_gssapi_server_check_mech(Gssctxt **dum, gss_OID oid, const char *data,
+ const char *dummy) {
+ Gssctxt *ctx = NULL;
+ int res;
+
+ res = !GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx, oid)));
+ ssh_gssapi_delete_ctx(&ctx);
+
+ return (res);
+}
+
+/* Unprivileged */
void
ssh_gssapi_supported_oids(gss_OID_set *oidset)
{
@@ -150,7 +175,9 @@ ssh_gssapi_supported_oids(gss_OID_set *o
gss_OID_set supported;
gss_create_empty_oid_set(&min_status, oidset);
- gss_indicate_mechs(&min_status, &supported);
+
+ if (GSS_ERROR(gss_indicate_mechs(&min_status, &supported)))
+ return;
while (supported_mechs[i]->name != NULL) {
if (GSS_ERROR(gss_test_oid_set_member(&min_status,
@@ -276,8 +303,48 @@ OM_uint32
ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
{
int i = 0;
+ int equal = 0;
+ gss_name_t new_name = GSS_C_NO_NAME;
+ gss_buffer_desc ename = GSS_C_EMPTY_BUFFER;
+
+ if (options.gss_store_rekey && client->used && ctx->client_creds) {
+ if (client->mech->oid.length != ctx->oid->length ||
+ (memcmp(client->mech->oid.elements,
+ ctx->oid->elements, ctx->oid->length) !=0)) {
+ debug("Rekeyed credentials have different mechanism");
+ return GSS_S_COMPLETE;
+ }
+
+ if ((ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
+ ctx->client_creds, ctx->oid, &new_name,
+ NULL, NULL, NULL))) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
+
+ ctx->major = gss_compare_name(&ctx->minor, client->name,
+ new_name, &equal);
+
+ if (GSS_ERROR(ctx->major)) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
+
+ if (!equal) {
+ debug("Rekeyed credentials have different name");
+ return GSS_S_COMPLETE;
+ }
- gss_buffer_desc ename;
+ debug("Marking rekeyed credentials for export");
+
+ gss_release_name(&ctx->minor, &client->name);
+ gss_release_cred(&ctx->minor, &client->creds);
+ client->name = new_name;
+ client->creds = ctx->client_creds;
+ ctx->client_creds = GSS_C_NO_CREDENTIAL;
+ client->updated = 1;
+ return GSS_S_COMPLETE;
+ }
client->mech = NULL;
@@ -292,6 +359,13 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_g
if (client->mech == NULL)
return GSS_S_FAILURE;
+ if (ctx->client_creds &&
+ (ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
+ ctx->client_creds, ctx->oid, &client->name, NULL, NULL, NULL))) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
+
if ((ctx->major = gss_display_name(&ctx->minor, ctx->client,
&client->displayname, NULL))) {
ssh_gssapi_error(ctx);
@@ -309,6 +383,8 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_g
return (ctx->major);
}
+ gss_release_buffer(&ctx->minor, &ename);
+
/* We can't copy this structure, so we just move the pointer to it */
client->creds = ctx->client_creds;
ctx->client_creds = GSS_C_NO_CREDENTIAL;
@@ -319,11 +395,20 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_g
void
ssh_gssapi_cleanup_creds(void)
{
- if (gssapi_client.store.filename != NULL) {
- /* Unlink probably isn't sufficient */
- debug("removing gssapi cred file\"%s\"",
- gssapi_client.store.filename);
- unlink(gssapi_client.store.filename);
+ krb5_ccache ccache = NULL;
+ krb5_error_code problem;
+
+ if (gssapi_client.store.data != NULL) {
+ if ((problem = krb5_cc_resolve(gssapi_client.store.data, gssapi_client.store.envval, &ccache))) {
+ debug("%s: krb5_cc_resolve(): %.100s", __func__,
+ krb5_get_err_text(gssapi_client.store.data, problem));
+ } else if ((problem = krb5_cc_destroy(gssapi_client.store.data, ccache))) {
+ debug("%s: krb5_cc_destroy(): %.100s", __func__,
+ krb5_get_err_text(gssapi_client.store.data, problem));
+ } else {
+ krb5_free_context(gssapi_client.store.data);
+ gssapi_client.store.data = NULL;
+ }
}
}
@@ -356,19 +441,23 @@ ssh_gssapi_do_child(char ***envp, u_int
/* Privileged */
int
-ssh_gssapi_userok(char *user)
+ssh_gssapi_userok(char *user, struct passwd *pw, int kex)
{
OM_uint32 lmin;
+ (void) kex; /* used in privilege separation */
+
if (gssapi_client.exportedname.length == 0 ||
gssapi_client.exportedname.value == NULL) {
debug("No suitable client data");
return 0;
}
if (gssapi_client.mech && gssapi_client.mech->userok)
- if ((*gssapi_client.mech->userok)(&gssapi_client, user))
+ if ((*gssapi_client.mech->userok)(&gssapi_client, user)) {
+ gssapi_client.used = 1;
+ gssapi_client.store.owner = pw;
return 1;
- else {
+ } else {
/* Destroy delegated credentials if userok fails */
gss_release_buffer(&lmin, &gssapi_client.displayname);
gss_release_buffer(&lmin, &gssapi_client.exportedname);
@@ -382,14 +471,90 @@ ssh_gssapi_userok(char *user)
return (0);
}
-/* Privileged */
-OM_uint32
-ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
+/* These bits are only used for rekeying. The unpriviledged child is running
+ * as the user, the monitor is root.
+ *
+ * In the child, we want to :
+ * *) Ask the monitor to store our credentials into the store we specify
+ * *) If it succeeds, maybe do a PAM update
+ */
+
+/* Stuff for PAM */
+
+#ifdef USE_PAM
+static int ssh_gssapi_simple_conv(int n, const struct pam_message **msg,
+ struct pam_response **resp, void *data)
{
- ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
- gssbuf, gssmic, NULL);
+ return (PAM_CONV_ERR);
+}
+#endif
- return (ctx->major);
+void
+ssh_gssapi_rekey_creds(void) {
+ int ok;
+#ifdef USE_PAM
+ int ret;
+ pam_handle_t *pamh = NULL;
+ struct pam_conv pamconv = {ssh_gssapi_simple_conv, NULL};
+ char *envstr;
+#endif
+
+ if (gssapi_client.store.filename == NULL &&
+ gssapi_client.store.envval == NULL &&
+ gssapi_client.store.envvar == NULL)
+ return;
+
+ ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store));
+
+ if (!ok)
+ return;
+
+ debug("Rekeyed credentials stored successfully");
+
+ /* Actually managing to play with the ssh pam stack from here will
+ * be next to impossible. In any case, we may want different options
+ * for rekeying. So, use our own :)
+ */
+#ifdef USE_PAM
+ if (!use_privsep) {
+ debug("Not even going to try and do PAM with privsep disabled");
+ return;
+ }
+
+ ret = pam_start("sshd-rekey", gssapi_client.store.owner->pw_name,
+ &pamconv, &pamh);
+ if (ret)
+ return;
+
+ xasprintf(&envstr, "%s=%s", gssapi_client.store.envvar,
+ gssapi_client.store.envval);
+
+ ret = pam_putenv(pamh, envstr);
+ if (!ret)
+ pam_setcred(pamh, PAM_REINITIALIZE_CRED);
+ pam_end(pamh, PAM_SUCCESS);
+#endif
+}
+
+int
+ssh_gssapi_update_creds(ssh_gssapi_ccache *store) {
+ int ok = 0;
+
+ /* Check we've got credentials to store */
+ if (!gssapi_client.updated)
+ return 0;
+
+ gssapi_client.updated = 0;
+
+ temporarily_use_uid(gssapi_client.store.owner);
+ if (gssapi_client.mech && gssapi_client.mech->updatecreds)
+ ok = (*gssapi_client.mech->updatecreds)(store, &gssapi_client);
+ else
+ debug("No update function for this mechanism");
+
+ restore_uid();
+
+ return ok;
}
/* Privileged */
Index: openssh-8.8p1/kex.c
===================================================================
--- openssh-8.8p1.orig/kex.c
+++ openssh-8.8p1/kex.c
@@ -57,11 +57,16 @@
#include "misc.h"
#include "dispatch.h"
#include "monitor.h"
+#include "xmalloc.h"
#include "ssherr.h"
#include "sshbuf.h"
#include "digest.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
#include "fips.h"
/* prototype */
@@ -119,6 +124,19 @@ static const struct kexalg kexalgs_all[]
#endif /* HAVE_EVP_SHA256 || !WITH_OPENSSL */
{ NULL, 0, -1, -1},
};
+static const struct kexalg gss_kexalgs[] = {
+#ifdef GSSAPI
+ { KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 },
+ { KEX_GSS_GRP1_SHA1_ID, KEX_GSS_GRP1_SHA1, 0, SSH_DIGEST_SHA1 },
+ { KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 },
+ { KEX_GSS_GRP14_SHA256_ID, KEX_GSS_GRP14_SHA256, 0, SSH_DIGEST_SHA256 },
+ { KEX_GSS_GRP16_SHA512_ID, KEX_GSS_GRP16_SHA512, 0, SSH_DIGEST_SHA512 },
+ { KEX_GSS_NISTP256_SHA256_ID, KEX_GSS_NISTP256_SHA256,
+ NID_X9_62_prime256v1, SSH_DIGEST_SHA256 },
+ { KEX_GSS_C25519_SHA256_ID, KEX_GSS_C25519_SHA256, 0, SSH_DIGEST_SHA256 },
+#endif
+ { NULL, 0, -1, -1 },
+};
static const struct kexalg kexalgs_fips140_2[] = {
#ifdef WITH_OPENSSL
@@ -146,12 +164,12 @@ static const struct kexalg kexalgs_fips1
/* Returns array of macs available depending on selected FIPS mode */
static const struct kexalg *
-fips_select_kexalgs(void)
+fips_select_kexalgs(const struct kexalg *algs)
{
int fips = fips_mode();
switch (fips) {
case 0:
- return kexalgs_all;
+ return algs;
case 1:
return kexalgs_fips140_2;
default:
@@ -162,13 +180,13 @@ fips_select_kexalgs(void)
}
char *
-kex_alg_list(char sep)
+kex_alg_list_internal(char sep, const struct kexalg *algs)
{
char *ret = NULL, *tmp;
size_t nlen, rlen = 0;
const struct kexalg *k;
- for (k = fips_select_kexalgs(); k->name != NULL; k++) {
+ for (k = fips_select_kexalgs(algs); k->name != NULL; k++) {
if (ret != NULL)
ret[rlen++] = sep;
nlen = strlen(k->name);
@@ -183,15 +201,31 @@ kex_alg_list(char sep)
return ret;
}
+char *
+kex_alg_list(char sep)
+{
+ return kex_alg_list_internal(sep, kexalgs_all);
+}
+
+char *
+kex_gss_alg_list(char sep)
+{
+ return kex_alg_list_internal(sep, gss_kexalgs);
+}
+
static const struct kexalg *
kex_alg_by_name(const char *name)
{
const struct kexalg *k;
- for (k = fips_select_kexalgs(); k->name != NULL; k++) {
+ for (k = fips_select_kexalgs(kexalgs_all); k->name != NULL; k++) {
if (strcmp(k->name, name) == 0)
return k;
}
+ for (k = gss_kexalgs; k->name != NULL; k++) {
+ if (strncmp(k->name, name, strlen(k->name)) == 0)
+ return k;
+ }
return NULL;
}
@@ -363,6 +397,29 @@ kex_assemble_names(char **listp, const c
return r;
}
+/* Validate GSS KEX method name list */
+int
+kex_gss_names_valid(const char *names)
+{
+ char *s, *cp, *p;
+
+ if (names == NULL || *names == '\0')
+ return 0;
+ s = cp = xstrdup(names);
+ for ((p = strsep(&cp, ",")); p && *p != '\0';
+ (p = strsep(&cp, ","))) {
+ if (strncmp(p, "gss-", 4) != 0
+ || kex_alg_by_name(p) == NULL) {
+ error("Unsupported KEX algorithm \"%.100s\"", p);
+ free(s);
+ return 0;
+ }
+ }
+ debug3("gss kex names ok: [%s]", names);
+ free(s);
+ return 1;
+}
+
/* put algorithm proposal into buffer */
int
kex_prop2buf(struct sshbuf *b, char *proposal[PROPOSAL_MAX])
@@ -745,6 +802,9 @@ kex_free(struct kex *kex)
sshbuf_free(kex->server_version);
sshbuf_free(kex->client_pub);
sshbuf_free(kex->session_id);
+#ifdef GSSAPI
+ free(kex->gss_host);
+#endif /* GSSAPI */
free(kex->failed_choice);
free(kex->hostkey_alg);
free(kex->name);
Index: openssh-8.8p1/kex.h
===================================================================
--- openssh-8.8p1.orig/kex.h
+++ openssh-8.8p1/kex.h
@@ -102,6 +102,15 @@ enum kex_exchange {
KEX_ECDH_SHA2,
KEX_C25519_SHA256,
KEX_KEM_SNTRUP761X25519_SHA512,
+#ifdef GSSAPI
+ KEX_GSS_GRP1_SHA1,
+ KEX_GSS_GRP14_SHA1,
+ KEX_GSS_GRP14_SHA256,
+ KEX_GSS_GRP16_SHA512,
+ KEX_GSS_GEX_SHA1,
+ KEX_GSS_NISTP256_SHA256,
+ KEX_GSS_C25519_SHA256,
+#endif
KEX_MAX
};
@@ -152,6 +161,12 @@ struct kex {
u_int flags;
int hash_alg;
int ec_nid;
+#ifdef GSSAPI
+ int gss_deleg_creds;
+ int gss_trust_dns;
+ char *gss_host;
+ char *gss_client;
+#endif
char *failed_choice;
int (*verify_host_key)(struct sshkey *, struct ssh *);
struct sshkey *(*load_host_public_key)(int, int, struct ssh *);
@@ -173,8 +188,10 @@ struct kex {
int kex_names_valid(const char *);
char *kex_alg_list(char);
+char *kex_gss_alg_list(char);
char *kex_names_cat(const char *, const char *);
int kex_assemble_names(char **, const char *, const char *);
+int kex_gss_names_valid(const char *);
int kex_exchange_identification(struct ssh *, int, const char *);
@@ -202,6 +219,12 @@ int kexgex_client(struct ssh *);
int kexgex_server(struct ssh *);
int kex_gen_client(struct ssh *);
int kex_gen_server(struct ssh *);
+#ifdef GSSAPI
+int kexgssgex_client(struct ssh *);
+int kexgssgex_server(struct ssh *);
+int kexgss_client(struct ssh *);
+int kexgss_server(struct ssh *);
+#endif
int kex_dh_keypair(struct kex *);
int kex_dh_enc(struct kex *, const struct sshbuf *, struct sshbuf **,
@@ -234,6 +257,12 @@ int kexgex_hash(int, const struct sshbu
const BIGNUM *, const u_char *, size_t,
u_char *, size_t *);
+int kex_gen_hash(int hash_alg, const struct sshbuf *client_version,
+ const struct sshbuf *server_version, const struct sshbuf *client_kexinit,
+ const struct sshbuf *server_kexinit, const struct sshbuf *server_host_key_blob,
+ const struct sshbuf *client_pub, const struct sshbuf *server_pub,
+ const struct sshbuf *shared_secret, u_char *hash, size_t *hashlen);
+
void kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
__attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
__attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
Index: openssh-8.8p1/kexdh.c
===================================================================
--- openssh-8.8p1.orig/kexdh.c
+++ openssh-8.8p1/kexdh.c
@@ -49,13 +49,23 @@ kex_dh_keygen(struct kex *kex)
{
switch (kex->kex_type) {
case KEX_DH_GRP1_SHA1:
+#ifdef GSSAPI
+ case KEX_GSS_GRP1_SHA1:
+#endif
kex->dh = dh_new_group1();
break;
case KEX_DH_GRP14_SHA1:
case KEX_DH_GRP14_SHA256:
+#ifdef GSSAPI
+ case KEX_GSS_GRP14_SHA1:
+ case KEX_GSS_GRP14_SHA256:
+#endif
kex->dh = dh_new_group14();
break;
case KEX_DH_GRP16_SHA512:
+#ifdef GSSAPI
+ case KEX_GSS_GRP16_SHA512:
+#endif
kex->dh = dh_new_group16();
break;
case KEX_DH_GRP18_SHA512:
Index: openssh-8.8p1/kexgen.c
===================================================================
--- openssh-8.8p1.orig/kexgen.c
+++ openssh-8.8p1/kexgen.c
@@ -44,7 +44,7 @@
static int input_kex_gen_init(int, u_int32_t, struct ssh *);
static int input_kex_gen_reply(int type, u_int32_t seq, struct ssh *ssh);
-static int
+int
kex_gen_hash(
int hash_alg,
const struct sshbuf *client_version,
Index: openssh-8.8p1/kexgssc.c
===================================================================
--- /dev/null
+++ openssh-8.8p1/kexgssc.c
@@ -0,0 +1,595 @@
+/*
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#if defined(GSSAPI) && defined(WITH_OPENSSL)
+
+#include "includes.h"
+
+#include <openssl/crypto.h>
+#include <openssl/bn.h>
+
+#include <string.h>
+
+#include "xmalloc.h"
+#include "sshbuf.h"
+#include "ssh2.h"
+#include "sshkey.h"
+#include "cipher.h"
+#include "kex.h"
+#include "log.h"
+#include "packet.h"
+#include "dh.h"
+#include "digest.h"
+#include "ssherr.h"
+
+#include "ssh-gss.h"
+
+int
+kexgss_client(struct ssh *ssh)
+{
+ struct kex *kex = ssh->kex;
+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER,
+ recv_tok = GSS_C_EMPTY_BUFFER,
+ gssbuf, msg_tok = GSS_C_EMPTY_BUFFER, *token_ptr;
+ Gssctxt *ctxt;
+ OM_uint32 maj_status, min_status, ret_flags;
+ struct sshbuf *server_blob = NULL;
+ struct sshbuf *shared_secret = NULL;
+ struct sshbuf *server_host_key_blob = NULL;
+ struct sshbuf *empty = sshbuf_new();
+ u_char *msg;
+ int type = 0;
+ int first = 1;
+ u_char hash[SSH_DIGEST_MAX_LENGTH];
+ size_t hashlen;
+ u_char c;
+ int r;
+
+ /* Initialise our GSSAPI world */
+ ssh_gssapi_build_ctx(&ctxt);
+ if (ssh_gssapi_id_kex(ctxt, kex->name, kex->kex_type)
+ == GSS_C_NO_OID)
+ fatal("Couldn't identify host exchange");
+
+ if (ssh_gssapi_import_name(ctxt, kex->gss_host))
+ fatal("Couldn't import hostname");
+
+ if (kex->gss_client &&
+ ssh_gssapi_client_identity(ctxt, kex->gss_client))
+ fatal("Couldn't acquire client credentials");
+
+ /* Step 1 */
+ switch (kex->kex_type) {
+ case KEX_GSS_GRP1_SHA1:
+ case KEX_GSS_GRP14_SHA1:
+ case KEX_GSS_GRP14_SHA256:
+ case KEX_GSS_GRP16_SHA512:
+ r = kex_dh_keypair(kex);
+ break;
+ case KEX_GSS_NISTP256_SHA256:
+ r = kex_ecdh_keypair(kex);
+ break;
+ case KEX_GSS_C25519_SHA256:
+ r = kex_c25519_keypair(kex);
+ break;
+ default:
+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+ }
+ if (r != 0)
+ return r;
+
+ token_ptr = GSS_C_NO_BUFFER;
+
+ do {
+ debug("Calling gss_init_sec_context");
+
+ maj_status = ssh_gssapi_init_ctx(ctxt,
+ kex->gss_deleg_creds, token_ptr, &send_tok,
+ &ret_flags);
+
+ if (GSS_ERROR(maj_status)) {
+ /* XXX Useles code: Missing send? */
+ if (send_tok.length != 0) {
+ if ((r = sshpkt_start(ssh,
+ SSH2_MSG_KEXGSS_CONTINUE)) != 0 ||
+ (r = sshpkt_put_string(ssh, send_tok.value,
+ send_tok.length)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ }
+ fatal("gss_init_context failed");
+ }
+
+ /* If we've got an old receive buffer get rid of it */
+ if (token_ptr != GSS_C_NO_BUFFER)
+ gss_release_buffer(&min_status, &recv_tok);
+
+ if (maj_status == GSS_S_COMPLETE) {
+ /* If mutual state flag is not true, kex fails */
+ if (!(ret_flags & GSS_C_MUTUAL_FLAG))
+ fatal("Mutual authentication failed");
+
+ /* If integ avail flag is not true kex fails */
+ if (!(ret_flags & GSS_C_INTEG_FLAG))
+ fatal("Integrity check failed");
+ }
+
+ /*
+ * If we have data to send, then the last message that we
+ * received cannot have been a 'complete'.
+ */
+ if (send_tok.length != 0) {
+ if (first) {
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_INIT)) != 0 ||
+ (r = sshpkt_put_string(ssh, send_tok.value,
+ send_tok.length)) != 0 ||
+ (r = sshpkt_put_stringb(ssh, kex->client_pub)) != 0)
+ fatal("failed to construct packet: %s", ssh_err(r));
+ first = 0;
+ } else {
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_CONTINUE)) != 0 ||
+ (r = sshpkt_put_string(ssh, send_tok.value,
+ send_tok.length)) != 0)
+ fatal("failed to construct packet: %s", ssh_err(r));
+ }
+ if ((r = sshpkt_send(ssh)) != 0)
+ fatal("failed to send packet: %s", ssh_err(r));
+ gss_release_buffer(&min_status, &send_tok);
+
+ /* If we've sent them data, they should reply */
+ do {
+ type = ssh_packet_read(ssh);
+ if (type == SSH2_MSG_KEXGSS_HOSTKEY) {
+ debug("Received KEXGSS_HOSTKEY");
+ if (server_host_key_blob)
+ fatal("Server host key received more than once");
+ if ((r = sshpkt_getb_froms(ssh, &server_host_key_blob)) != 0)
+ fatal("Failed to read server host key: %s", ssh_err(r));
+ }
+ } while (type == SSH2_MSG_KEXGSS_HOSTKEY);
+
+ switch (type) {
+ case SSH2_MSG_KEXGSS_CONTINUE:
+ debug("Received GSSAPI_CONTINUE");
+ if (maj_status == GSS_S_COMPLETE)
+ fatal("GSSAPI Continue received from server when complete");
+ if ((r = ssh_gssapi_sshpkt_get_buffer_desc(ssh,
+ &recv_tok)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("Failed to read token: %s", ssh_err(r));
+ break;
+ case SSH2_MSG_KEXGSS_COMPLETE:
+ debug("Received GSSAPI_COMPLETE");
+ if (msg_tok.value != NULL)
+ fatal("Received GSSAPI_COMPLETE twice?");
+ if ((r = sshpkt_getb_froms(ssh, &server_blob)) != 0 ||
+ (r = ssh_gssapi_sshpkt_get_buffer_desc(ssh,
+ &msg_tok)) != 0)
+ fatal("Failed to read message: %s", ssh_err(r));
+
+ /* Is there a token included? */
+ if ((r = sshpkt_get_u8(ssh, &c)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ if (c) {
+ if ((r = ssh_gssapi_sshpkt_get_buffer_desc(
+ ssh, &recv_tok)) != 0)
+ fatal("Failed to read token: %s", ssh_err(r));
+ /* If we're already complete - protocol error */
+ if (maj_status == GSS_S_COMPLETE)
+ sshpkt_disconnect(ssh, "Protocol error: received token when complete");
+ } else {
+ /* No token included */
+ if (maj_status != GSS_S_COMPLETE)
+ sshpkt_disconnect(ssh, "Protocol error: did not receive final token");
+ }
+ if ((r = sshpkt_get_end(ssh)) != 0) {
+ fatal("Expecting end of packet.");
+ }
+ break;
+ case SSH2_MSG_KEXGSS_ERROR:
+ debug("Received Error");
+ if ((r = sshpkt_get_u32(ssh, &maj_status)) != 0 ||
+ (r = sshpkt_get_u32(ssh, &min_status)) != 0 ||
+ (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
+ (r = sshpkt_get_string(ssh, NULL, NULL)) != 0 || /* lang tag */
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("sshpkt_get failed: %s", ssh_err(r));
+ fatal("GSSAPI Error: \n%.400s", msg);
+ default:
+ sshpkt_disconnect(ssh, "Protocol error: didn't expect packet type %d",
+ type);
+ }
+ token_ptr = &recv_tok;
+ } else {
+ /* No data, and not complete */
+ if (maj_status != GSS_S_COMPLETE)
+ fatal("Not complete, and no token output");
+ }
+ } while (maj_status & GSS_S_CONTINUE_NEEDED);
+
+ /*
+ * We _must_ have received a COMPLETE message in reply from the
+ * server, which will have set server_blob and msg_tok
+ */
+
+ if (type != SSH2_MSG_KEXGSS_COMPLETE)
+ fatal("Didn't receive a SSH2_MSG_KEXGSS_COMPLETE when I expected it");
+
+ /* compute shared secret */
+ switch (kex->kex_type) {
+ case KEX_GSS_GRP1_SHA1:
+ case KEX_GSS_GRP14_SHA1:
+ case KEX_GSS_GRP14_SHA256:
+ case KEX_GSS_GRP16_SHA512:
+ r = kex_dh_dec(kex, server_blob, &shared_secret);
+ break;
+ case KEX_GSS_C25519_SHA256:
+ if (sshbuf_ptr(server_blob)[sshbuf_len(server_blob)] & 0x80)
+ fatal("The received key has MSB of last octet set!");
+ r = kex_c25519_dec(kex, server_blob, &shared_secret);
+ break;
+ case KEX_GSS_NISTP256_SHA256:
+ if (sshbuf_len(server_blob) != 65)
+ fatal("The received NIST-P256 key did not match"
+ "expected length (expected 65, got %zu)", sshbuf_len(server_blob));
+
+ if (sshbuf_ptr(server_blob)[0] != POINT_CONVERSION_UNCOMPRESSED)
+ fatal("The received NIST-P256 key does not have first octet 0x04");
+
+ r = kex_ecdh_dec(kex, server_blob, &shared_secret);
+ break;
+ default:
+ r = SSH_ERR_INVALID_ARGUMENT;
+ break;
+ }
+ if (r != 0)
+ goto out;
+
+ hashlen = sizeof(hash);
+ if ((r = kex_gen_hash(
+ kex->hash_alg,
+ kex->client_version,
+ kex->server_version,
+ kex->my,
+ kex->peer,
+ (server_host_key_blob ? server_host_key_blob : empty),
+ kex->client_pub,
+ server_blob,
+ shared_secret,
+ hash, &hashlen)) != 0)
+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+
+ gssbuf.value = hash;
+ gssbuf.length = hashlen;
+
+ /* Verify that the hash matches the MIC we just got. */
+ if (GSS_ERROR(ssh_gssapi_checkmic(ctxt, &gssbuf, &msg_tok)))
+ sshpkt_disconnect(ssh, "Hash's MIC didn't verify");
+
+ gss_release_buffer(&min_status, &msg_tok);
+
+ if (kex->gss_deleg_creds)
+ ssh_gssapi_credentials_updated(ctxt);
+
+ if (gss_kex_context == NULL)
+ gss_kex_context = ctxt;
+ else
+ ssh_gssapi_delete_ctx(&ctxt);
+
+ if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
+ r = kex_send_newkeys(ssh);
+
+out:
+ explicit_bzero(hash, sizeof(hash));
+ explicit_bzero(kex->c25519_client_key, sizeof(kex->c25519_client_key));
+ sshbuf_free(empty);
+ sshbuf_free(server_host_key_blob);
+ sshbuf_free(server_blob);
+ sshbuf_free(shared_secret);
+ sshbuf_free(kex->client_pub);
+ kex->client_pub = NULL;
+ return r;
+}
+
+int
+kexgssgex_client(struct ssh *ssh)
+{
+ struct kex *kex = ssh->kex;
+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER,
+ recv_tok = GSS_C_EMPTY_BUFFER, gssbuf,
+ msg_tok = GSS_C_EMPTY_BUFFER, *token_ptr;
+ Gssctxt *ctxt;
+ OM_uint32 maj_status, min_status, ret_flags;
+ struct sshbuf *shared_secret = NULL;
+ BIGNUM *p = NULL;
+ BIGNUM *g = NULL;
+ struct sshbuf *buf = NULL;
+ struct sshbuf *server_host_key_blob = NULL;
+ struct sshbuf *server_blob = NULL;
+ BIGNUM *dh_server_pub = NULL;
+ u_char *msg;
+ int type = 0;
+ int first = 1;
+ u_char hash[SSH_DIGEST_MAX_LENGTH];
+ size_t hashlen;
+ const BIGNUM *pub_key, *dh_p, *dh_g;
+ int nbits = 0, min = DH_GRP_MIN, max = DH_GRP_MAX;
+ struct sshbuf *empty = sshbuf_new();
+ u_char c;
+ int r;
+
+ /* Initialise our GSSAPI world */
+ ssh_gssapi_build_ctx(&ctxt);
+ if (ssh_gssapi_id_kex(ctxt, kex->name, kex->kex_type)
+ == GSS_C_NO_OID)
+ fatal("Couldn't identify host exchange");
+
+ if (ssh_gssapi_import_name(ctxt, kex->gss_host))
+ fatal("Couldn't import hostname");
+
+ if (kex->gss_client &&
+ ssh_gssapi_client_identity(ctxt, kex->gss_client))
+ fatal("Couldn't acquire client credentials");
+
+ debug("Doing group exchange");
+ nbits = dh_estimate(kex->dh_need * 8);
+
+ kex->min = DH_GRP_MIN;
+ kex->max = DH_GRP_MAX;
+ kex->nbits = nbits;
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_GROUPREQ)) != 0 ||
+ (r = sshpkt_put_u32(ssh, min)) != 0 ||
+ (r = sshpkt_put_u32(ssh, nbits)) != 0 ||
+ (r = sshpkt_put_u32(ssh, max)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal("Failed to construct a packet: %s", ssh_err(r));
+
+ if ((r = ssh_packet_read_expect(ssh, SSH2_MSG_KEXGSS_GROUP)) != 0)
+ fatal("Error: %s", ssh_err(r));
+
+ if ((r = sshpkt_get_bignum2(ssh, &p)) != 0 ||
+ (r = sshpkt_get_bignum2(ssh, &g)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("shpkt_get_bignum2 failed: %s", ssh_err(r));
+
+ if (BN_num_bits(p) < min || BN_num_bits(p) > max)
+ fatal("GSSGRP_GEX group out of range: %d !< %d !< %d",
+ min, BN_num_bits(p), max);
+
+ if ((kex->dh = dh_new_group(g, p)) == NULL)
+ fatal("dn_new_group() failed");
+ p = g = NULL; /* belong to kex->dh now */
+
+ if ((r = dh_gen_key(kex->dh, kex->we_need * 8)) != 0)
+ goto out;
+ DH_get0_key(kex->dh, &pub_key, NULL);
+
+ token_ptr = GSS_C_NO_BUFFER;
+
+ do {
+ /* Step 2 - call GSS_Init_sec_context() */
+ debug("Calling gss_init_sec_context");
+
+ maj_status = ssh_gssapi_init_ctx(ctxt,
+ kex->gss_deleg_creds, token_ptr, &send_tok,
+ &ret_flags);
+
+ if (GSS_ERROR(maj_status)) {
+ /* XXX Useles code: Missing send? */
+ if (send_tok.length != 0) {
+ if ((r = sshpkt_start(ssh,
+ SSH2_MSG_KEXGSS_CONTINUE)) != 0 ||
+ (r = sshpkt_put_string(ssh, send_tok.value,
+ send_tok.length)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ }
+ fatal("gss_init_context failed");
+ }
+
+ /* If we've got an old receive buffer get rid of it */
+ if (token_ptr != GSS_C_NO_BUFFER)
+ gss_release_buffer(&min_status, &recv_tok);
+
+ if (maj_status == GSS_S_COMPLETE) {
+ /* If mutual state flag is not true, kex fails */
+ if (!(ret_flags & GSS_C_MUTUAL_FLAG))
+ fatal("Mutual authentication failed");
+
+ /* If integ avail flag is not true kex fails */
+ if (!(ret_flags & GSS_C_INTEG_FLAG))
+ fatal("Integrity check failed");
+ }
+
+ /*
+ * If we have data to send, then the last message that we
+ * received cannot have been a 'complete'.
+ */
+ if (send_tok.length != 0) {
+ if (first) {
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_INIT)) != 0 ||
+ (r = sshpkt_put_string(ssh, send_tok.value,
+ send_tok.length)) != 0 ||
+ (r = sshpkt_put_bignum2(ssh, pub_key)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ first = 0;
+ } else {
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_CONTINUE)) != 0 ||
+ (r = sshpkt_put_string(ssh,send_tok.value,
+ send_tok.length)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ }
+ if ((r = sshpkt_send(ssh)) != 0)
+ fatal("sshpkt_send failed: %s", ssh_err(r));
+ gss_release_buffer(&min_status, &send_tok);
+
+ /* If we've sent them data, they should reply */
+ do {
+ type = ssh_packet_read(ssh);
+ if (type == SSH2_MSG_KEXGSS_HOSTKEY) {
+ debug("Received KEXGSS_HOSTKEY");
+ if (server_host_key_blob)
+ fatal("Server host key received more than once");
+ if ((r = sshpkt_getb_froms(ssh, &server_host_key_blob)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ }
+ } while (type == SSH2_MSG_KEXGSS_HOSTKEY);
+
+ switch (type) {
+ case SSH2_MSG_KEXGSS_CONTINUE:
+ debug("Received GSSAPI_CONTINUE");
+ if (maj_status == GSS_S_COMPLETE)
+ fatal("GSSAPI Continue received from server when complete");
+ if ((r = ssh_gssapi_sshpkt_get_buffer_desc(ssh,
+ &recv_tok)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ break;
+ case SSH2_MSG_KEXGSS_COMPLETE:
+ debug("Received GSSAPI_COMPLETE");
+ if (msg_tok.value != NULL)
+ fatal("Received GSSAPI_COMPLETE twice?");
+ if ((r = sshpkt_getb_froms(ssh, &server_blob)) != 0 ||
+ (r = ssh_gssapi_sshpkt_get_buffer_desc(ssh,
+ &msg_tok)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+
+ /* Is there a token included? */
+ if ((r = sshpkt_get_u8(ssh, &c)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ if (c) {
+ if ((r = ssh_gssapi_sshpkt_get_buffer_desc(
+ ssh, &recv_tok)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ /* If we're already complete - protocol error */
+ if (maj_status == GSS_S_COMPLETE)
+ sshpkt_disconnect(ssh, "Protocol error: received token when complete");
+ } else {
+ /* No token included */
+ if (maj_status != GSS_S_COMPLETE)
+ sshpkt_disconnect(ssh, "Protocol error: did not receive final token");
+ }
+ break;
+ case SSH2_MSG_KEXGSS_ERROR:
+ debug("Received Error");
+ if ((r = sshpkt_get_u32(ssh, &maj_status)) != 0 ||
+ (r = sshpkt_get_u32(ssh, &min_status)) != 0 ||
+ (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
+ (r = sshpkt_get_string(ssh, NULL, NULL)) != 0 || /* lang tag */
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ fatal("GSSAPI Error: \n%.400s", msg);
+ default:
+ sshpkt_disconnect(ssh, "Protocol error: didn't expect packet type %d",
+ type);
+ }
+ token_ptr = &recv_tok;
+ } else {
+ /* No data, and not complete */
+ if (maj_status != GSS_S_COMPLETE)
+ fatal("Not complete, and no token output");
+ }
+ } while (maj_status & GSS_S_CONTINUE_NEEDED);
+
+ /*
+ * We _must_ have received a COMPLETE message in reply from the
+ * server, which will have set dh_server_pub and msg_tok
+ */
+
+ if (type != SSH2_MSG_KEXGSS_COMPLETE)
+ fatal("Didn't receive a SSH2_MSG_KEXGSS_COMPLETE when I expected it");
+
+ /* 7. C verifies that the key Q_S is valid */
+ /* 8. C computes shared secret */
+ if ((buf = sshbuf_new()) == NULL ||
+ (r = sshbuf_put_stringb(buf, server_blob)) != 0 ||
+ (r = sshbuf_get_bignum2(buf, &dh_server_pub)) != 0)
+ goto out;
+ sshbuf_free(buf);
+
+ if ((shared_secret = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+
+ if ((r = kex_dh_compute_key(kex, dh_server_pub, shared_secret)) != 0)
+ goto out;
+
+ DH_get0_pqg(kex->dh, &dh_p, NULL, &dh_g);
+ hashlen = sizeof(hash);
+ if ((r = kexgex_hash(
+ kex->hash_alg,
+ kex->client_version,
+ kex->server_version,
+ kex->my,
+ kex->peer,
+ (server_host_key_blob ? server_host_key_blob : empty),
+ kex->min, kex->nbits, kex->max,
+ dh_p, dh_g,
+ pub_key,
+ dh_server_pub,
+ sshbuf_ptr(shared_secret), sshbuf_len(shared_secret),
+ hash, &hashlen)) != 0)
+ fatal("Failed to calculate hash: %s", ssh_err(r));
+
+ gssbuf.value = hash;
+ gssbuf.length = hashlen;
+
+ /* Verify that the hash matches the MIC we just got. */
+ if (GSS_ERROR(ssh_gssapi_checkmic(ctxt, &gssbuf, &msg_tok)))
+ sshpkt_disconnect(ssh, "Hash's MIC didn't verify");
+
+ gss_release_buffer(&min_status, &msg_tok);
+
+ /* save session id */
+ if (kex->session_id == NULL) {
+ kex->session_id = sshbuf_new ();
+ if ((r = sshbuf_put(kex->session_id, hash, hashlen)) != 0)
+ goto out;
+ }
+
+ if (kex->gss_deleg_creds)
+ ssh_gssapi_credentials_updated(ctxt);
+
+ if (gss_kex_context == NULL)
+ gss_kex_context = ctxt;
+ else
+ ssh_gssapi_delete_ctx(&ctxt);
+
+ /* Finally derive the keys and send them */
+ if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
+ r = kex_send_newkeys(ssh);
+out:
+ sshbuf_free(server_blob);
+ sshbuf_free(empty);
+ explicit_bzero(hash, sizeof(hash));
+ DH_free(kex->dh);
+ kex->dh = NULL;
+ BN_clear_free(dh_server_pub);
+ sshbuf_free(shared_secret);
+ sshbuf_free(server_host_key_blob);
+ return r;
+}
+#endif /* defined(GSSAPI) && defined(WITH_OPENSSL) */
Index: openssh-8.8p1/kexgsss.c
===================================================================
--- /dev/null
+++ openssh-8.8p1/kexgsss.c
@@ -0,0 +1,474 @@
+/*
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#if defined(GSSAPI) && defined(WITH_OPENSSL)
+
+#include <string.h>
+
+#include <openssl/crypto.h>
+#include <openssl/bn.h>
+
+#include "xmalloc.h"
+#include "sshbuf.h"
+#include "ssh2.h"
+#include "sshkey.h"
+#include "cipher.h"
+#include "kex.h"
+#include "log.h"
+#include "packet.h"
+#include "dh.h"
+#include "ssh-gss.h"
+#include "monitor_wrap.h"
+#include "misc.h" /* servconf.h needs misc.h for struct ForwardOptions */
+#include "servconf.h"
+#include "ssh-gss.h"
+#include "digest.h"
+#include "ssherr.h"
+
+extern ServerOptions options;
+
+int
+kexgss_server(struct ssh *ssh)
+{
+ struct kex *kex = ssh->kex;
+ OM_uint32 maj_status, min_status;
+
+ /*
+ * Some GSSAPI implementations use the input value of ret_flags (an
+ * output variable) as a means of triggering mechanism specific
+ * features. Initializing it to zero avoids inadvertently
+ * activating this non-standard behaviour.
+ */
+
+ OM_uint32 ret_flags = 0;
+ gss_buffer_desc gssbuf, recv_tok, msg_tok;
+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+ Gssctxt *ctxt = NULL;
+ struct sshbuf *shared_secret = NULL;
+ struct sshbuf *client_pubkey = NULL;
+ struct sshbuf *server_pubkey = NULL;
+ struct sshbuf *empty = sshbuf_new();
+ int type = 0;
+ gss_OID oid;
+ char *mechs;
+ u_char hash[SSH_DIGEST_MAX_LENGTH];
+ size_t hashlen;
+ int r;
+
+ /* Initialise GSSAPI */
+
+ /* If we're rekeying, privsep means that some of the private structures
+ * in the GSSAPI code are no longer available. This kludges them back
+ * into life
+ */
+ if (!ssh_gssapi_oid_table_ok()) {
+ mechs = ssh_gssapi_server_mechanisms();
+ free(mechs);
+ }
+
+ debug2("%s: Identifying %s", __func__, kex->name);
+ oid = ssh_gssapi_id_kex(NULL, kex->name, kex->kex_type);
+ if (oid == GSS_C_NO_OID)
+ fatal("Unknown gssapi mechanism");
+
+ debug2("%s: Acquiring credentials", __func__);
+
+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, oid))))
+ fatal("Unable to acquire credentials for the server");
+
+ do {
+ debug("Wait SSH2_MSG_KEXGSS_INIT");
+ type = ssh_packet_read(ssh);
+ switch(type) {
+ case SSH2_MSG_KEXGSS_INIT:
+ if (client_pubkey != NULL)
+ fatal("Received KEXGSS_INIT after initialising");
+ if ((r = ssh_gssapi_sshpkt_get_buffer_desc(ssh,
+ &recv_tok)) != 0 ||
+ (r = sshpkt_getb_froms(ssh, &client_pubkey)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+
+ switch (kex->kex_type) {
+ case KEX_GSS_GRP1_SHA1:
+ case KEX_GSS_GRP14_SHA1:
+ case KEX_GSS_GRP14_SHA256:
+ case KEX_GSS_GRP16_SHA512:
+ r = kex_dh_enc(kex, client_pubkey, &server_pubkey,
+ &shared_secret);
+ break;
+ case KEX_GSS_NISTP256_SHA256:
+ r = kex_ecdh_enc(kex, client_pubkey, &server_pubkey,
+ &shared_secret);
+ break;
+ case KEX_GSS_C25519_SHA256:
+ r = kex_c25519_enc(kex, client_pubkey, &server_pubkey,
+ &shared_secret);
+ break;
+ default:
+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+ }
+ if (r != 0)
+ goto out;
+
+ /* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */
+ break;
+ case SSH2_MSG_KEXGSS_CONTINUE:
+ if ((r = ssh_gssapi_sshpkt_get_buffer_desc(ssh,
+ &recv_tok)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ break;
+ default:
+ sshpkt_disconnect(ssh,
+ "Protocol error: didn't expect packet type %d",
+ type);
+ }
+
+ maj_status = PRIVSEP(ssh_gssapi_accept_ctx(ctxt, &recv_tok,
+ &send_tok, &ret_flags));
+
+ gss_release_buffer(&min_status, &recv_tok);
+
+ if (maj_status != GSS_S_COMPLETE && send_tok.length == 0)
+ fatal("Zero length token output when incomplete");
+
+ if (client_pubkey == NULL)
+ fatal("No client public key");
+
+ if (maj_status & GSS_S_CONTINUE_NEEDED) {
+ debug("Sending GSSAPI_CONTINUE");
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_CONTINUE)) != 0 ||
+ (r = sshpkt_put_string(ssh, send_tok.value, send_tok.length)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ gss_release_buffer(&min_status, &send_tok);
+ }
+ } while (maj_status & GSS_S_CONTINUE_NEEDED);
+
+ if (GSS_ERROR(maj_status)) {
+ if (send_tok.length > 0) {
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_CONTINUE)) != 0 ||
+ (r = sshpkt_put_string(ssh, send_tok.value, send_tok.length)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ }
+ fatal("accept_ctx died");
+ }
+
+ if (!(ret_flags & GSS_C_MUTUAL_FLAG))
+ fatal("Mutual Authentication flag wasn't set");
+
+ if (!(ret_flags & GSS_C_INTEG_FLAG))
+ fatal("Integrity flag wasn't set");
+
+ hashlen = sizeof(hash);
+ if ((r = kex_gen_hash(
+ kex->hash_alg,
+ kex->client_version,
+ kex->server_version,
+ kex->peer,
+ kex->my,
+ empty,
+ client_pubkey,
+ server_pubkey,
+ shared_secret,
+ hash, &hashlen)) != 0)
+ goto out;
+
+ gssbuf.value = hash;
+ gssbuf.length = hashlen;
+
+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_sign(ctxt, &gssbuf, &msg_tok))))
+ fatal("Couldn't get MIC");
+
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_COMPLETE)) != 0 ||
+ (r = sshpkt_put_stringb(ssh, server_pubkey)) != 0 ||
+ (r = sshpkt_put_string(ssh, msg_tok.value, msg_tok.length)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+
+ if (send_tok.length != 0) {
+ if ((r = sshpkt_put_u8(ssh, 1)) != 0 || /* true */
+ (r = sshpkt_put_string(ssh, send_tok.value, send_tok.length)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ } else {
+ if ((r = sshpkt_put_u8(ssh, 0)) != 0) /* false */
+ fatal("sshpkt failed: %s", ssh_err(r));
+ }
+ if ((r = sshpkt_send(ssh)) != 0)
+ fatal("sshpkt_send failed: %s", ssh_err(r));
+
+ gss_release_buffer(&min_status, &send_tok);
+ gss_release_buffer(&min_status, &msg_tok);
+
+ if (gss_kex_context == NULL)
+ gss_kex_context = ctxt;
+ else
+ ssh_gssapi_delete_ctx(&ctxt);
+
+ if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
+ r = kex_send_newkeys(ssh);
+
+ /* If this was a rekey, then save out any delegated credentials we
+ * just exchanged. */
+ if (options.gss_store_rekey)
+ ssh_gssapi_rekey_creds();
+out:
+ sshbuf_free(empty);
+ explicit_bzero(hash, sizeof(hash));
+ sshbuf_free(shared_secret);
+ sshbuf_free(client_pubkey);
+ sshbuf_free(server_pubkey);
+ return r;
+}
+
+int
+kexgssgex_server(struct ssh *ssh)
+{
+ struct kex *kex = ssh->kex;
+ OM_uint32 maj_status, min_status;
+
+ /*
+ * Some GSSAPI implementations use the input value of ret_flags (an
+ * output variable) as a means of triggering mechanism specific
+ * features. Initializing it to zero avoids inadvertently
+ * activating this non-standard behaviour.
+ */
+
+ OM_uint32 ret_flags = 0;
+ gss_buffer_desc gssbuf, recv_tok, msg_tok;
+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+ Gssctxt *ctxt = NULL;
+ struct sshbuf *shared_secret = NULL;
+ int type = 0;
+ gss_OID oid;
+ char *mechs;
+ u_char hash[SSH_DIGEST_MAX_LENGTH];
+ size_t hashlen;
+ BIGNUM *dh_client_pub = NULL;
+ const BIGNUM *pub_key, *dh_p, *dh_g;
+ int min = -1, max = -1, nbits = -1;
+ int cmin = -1, cmax = -1; /* client proposal */
+ struct sshbuf *empty = sshbuf_new();
+ int r;
+
+ /* Initialise GSSAPI */
+
+ /* If we're rekeying, privsep means that some of the private structures
+ * in the GSSAPI code are no longer available. This kludges them back
+ * into life
+ */
+ if (!ssh_gssapi_oid_table_ok())
+ if ((mechs = ssh_gssapi_server_mechanisms()))
+ free(mechs);
+
+ debug2("%s: Identifying %s", __func__, kex->name);
+ oid = ssh_gssapi_id_kex(NULL, kex->name, kex->kex_type);
+ if (oid == GSS_C_NO_OID)
+ fatal("Unknown gssapi mechanism");
+
+ debug2("%s: Acquiring credentials", __func__);
+
+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, oid))))
+ fatal("Unable to acquire credentials for the server");
+
+ /* 5. S generates an ephemeral key pair (do the allocations early) */
+ debug("Doing group exchange");
+ ssh_packet_read_expect(ssh, SSH2_MSG_KEXGSS_GROUPREQ);
+ /* store client proposal to provide valid signature */
+ if ((r = sshpkt_get_u32(ssh, &cmin)) != 0 ||
+ (r = sshpkt_get_u32(ssh, &nbits)) != 0 ||
+ (r = sshpkt_get_u32(ssh, &cmax)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ kex->nbits = nbits;
+ kex->min = cmin;
+ kex->max = cmax;
+ min = MAX(DH_GRP_MIN, cmin);
+ max = MIN(DH_GRP_MAX, cmax);
+ nbits = MAXIMUM(DH_GRP_MIN, nbits);
+ nbits = MINIMUM(DH_GRP_MAX, nbits);
+ if (max < min || nbits < min || max < nbits)
+ fatal("GSS_GEX, bad parameters: %d !< %d !< %d",
+ min, nbits, max);
+ kex->dh = PRIVSEP(choose_dh(min, nbits, max));
+ if (kex->dh == NULL) {
+ sshpkt_disconnect(ssh, "Protocol error: no matching group found");
+ fatal("Protocol error: no matching group found");
+ }
+
+ DH_get0_pqg(kex->dh, &dh_p, NULL, &dh_g);
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_GROUP)) != 0 ||
+ (r = sshpkt_put_bignum2(ssh, dh_p)) != 0 ||
+ (r = sshpkt_put_bignum2(ssh, dh_g)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+
+ if ((r = ssh_packet_write_wait(ssh)) != 0)
+ fatal("ssh_packet_write_wait: %s", ssh_err(r));
+
+ /* Compute our exchange value in parallel with the client */
+ if ((r = dh_gen_key(kex->dh, kex->we_need * 8)) != 0)
+ goto out;
+
+ do {
+ debug("Wait SSH2_MSG_GSSAPI_INIT");
+ type = ssh_packet_read(ssh);
+ switch(type) {
+ case SSH2_MSG_KEXGSS_INIT:
+ if (dh_client_pub != NULL)
+ fatal("Received KEXGSS_INIT after initialising");
+ if ((r = ssh_gssapi_sshpkt_get_buffer_desc(ssh,
+ &recv_tok)) != 0 ||
+ (r = sshpkt_get_bignum2(ssh, &dh_client_pub)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+
+ /* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */
+ break;
+ case SSH2_MSG_KEXGSS_CONTINUE:
+ if ((r = ssh_gssapi_sshpkt_get_buffer_desc(ssh,
+ &recv_tok)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ break;
+ default:
+ sshpkt_disconnect(ssh,
+ "Protocol error: didn't expect packet type %d",
+ type);
+ }
+
+ maj_status = PRIVSEP(ssh_gssapi_accept_ctx(ctxt, &recv_tok,
+ &send_tok, &ret_flags));
+
+ gss_release_buffer(&min_status, &recv_tok);
+
+ if (maj_status != GSS_S_COMPLETE && send_tok.length == 0)
+ fatal("Zero length token output when incomplete");
+
+ if (dh_client_pub == NULL)
+ fatal("No client public key");
+
+ if (maj_status & GSS_S_CONTINUE_NEEDED) {
+ debug("Sending GSSAPI_CONTINUE");
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_CONTINUE)) != 0 ||
+ (r = sshpkt_put_string(ssh, send_tok.value, send_tok.length)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ gss_release_buffer(&min_status, &send_tok);
+ }
+ } while (maj_status & GSS_S_CONTINUE_NEEDED);
+
+ if (GSS_ERROR(maj_status)) {
+ if (send_tok.length > 0) {
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_CONTINUE)) != 0 ||
+ (r = sshpkt_put_string(ssh, send_tok.value, send_tok.length)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ }
+ fatal("accept_ctx died");
+ }
+
+ if (!(ret_flags & GSS_C_MUTUAL_FLAG))
+ fatal("Mutual Authentication flag wasn't set");
+
+ if (!(ret_flags & GSS_C_INTEG_FLAG))
+ fatal("Integrity flag wasn't set");
+
+ /* calculate shared secret */
+ if ((shared_secret = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if ((r = kex_dh_compute_key(kex, dh_client_pub, shared_secret)) != 0)
+ goto out;
+
+ DH_get0_key(kex->dh, &pub_key, NULL);
+ DH_get0_pqg(kex->dh, &dh_p, NULL, &dh_g);
+ hashlen = sizeof(hash);
+ if ((r = kexgex_hash(
+ kex->hash_alg,
+ kex->client_version,
+ kex->server_version,
+ kex->peer,
+ kex->my,
+ empty,
+ cmin, nbits, cmax,
+ dh_p, dh_g,
+ dh_client_pub,
+ pub_key,
+ sshbuf_ptr(shared_secret), sshbuf_len(shared_secret),
+ hash, &hashlen)) != 0)
+ fatal("kexgex_hash failed: %s", ssh_err(r));
+
+ gssbuf.value = hash;
+ gssbuf.length = hashlen;
+
+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_sign(ctxt, &gssbuf, &msg_tok))))
+ fatal("Couldn't get MIC");
+
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_COMPLETE)) != 0 ||
+ (r = sshpkt_put_bignum2(ssh, pub_key)) != 0 ||
+ (r = sshpkt_put_string(ssh, msg_tok.value, msg_tok.length)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+
+ if (send_tok.length != 0) {
+ if ((r = sshpkt_put_u8(ssh, 1)) != 0 || /* true */
+ (r = sshpkt_put_string(ssh, send_tok.value, send_tok.length)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ } else {
+ if ((r = sshpkt_put_u8(ssh, 0)) != 0) /* false */
+ fatal("sshpkt failed: %s", ssh_err(r));
+ }
+ if ((r = sshpkt_send(ssh)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+
+ gss_release_buffer(&min_status, &send_tok);
+ gss_release_buffer(&min_status, &msg_tok);
+
+ if (gss_kex_context == NULL)
+ gss_kex_context = ctxt;
+ else
+ ssh_gssapi_delete_ctx(&ctxt);
+
+ /* Finally derive the keys and send them */
+ if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
+ r = kex_send_newkeys(ssh);
+
+ /* If this was a rekey, then save out any delegated credentials we
+ * just exchanged. */
+ if (options.gss_store_rekey)
+ ssh_gssapi_rekey_creds();
+out:
+ sshbuf_free(empty);
+ explicit_bzero(hash, sizeof(hash));
+ DH_free(kex->dh);
+ kex->dh = NULL;
+ BN_clear_free(dh_client_pub);
+ sshbuf_free(shared_secret);
+ return r;
+}
+#endif /* defined(GSSAPI) && defined(WITH_OPENSSL) */
Index: openssh-8.8p1/monitor.c
===================================================================
--- openssh-8.8p1.orig/monitor.c
+++ openssh-8.8p1/monitor.c
@@ -145,6 +145,8 @@ int mm_answer_gss_setup_ctx(struct ssh *
int mm_answer_gss_accept_ctx(struct ssh *, int, struct sshbuf *);
int mm_answer_gss_userok(struct ssh *, int, struct sshbuf *);
int mm_answer_gss_checkmic(struct ssh *, int, struct sshbuf *);
+int mm_answer_gss_sign(struct ssh*, int, struct sshbuf *);
+int mm_answer_gss_updatecreds(struct ssh*, int, struct sshbuf *);
#endif
#ifdef SSH_AUDIT_EVENTS
@@ -217,11 +219,18 @@ struct mon_table mon_dispatch_proto20[]
{MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
{MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok},
{MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic},
+ {MONITOR_REQ_GSSSIGN, MON_ONCE, mm_answer_gss_sign},
#endif
{0, 0, NULL}
};
struct mon_table mon_dispatch_postauth20[] = {
+#ifdef GSSAPI
+ {MONITOR_REQ_GSSSETUP, 0, mm_answer_gss_setup_ctx},
+ {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
+ {MONITOR_REQ_GSSSIGN, 0, mm_answer_gss_sign},
+ {MONITOR_REQ_GSSUPCREDS, 0, mm_answer_gss_updatecreds},
+#endif
#ifdef WITH_OPENSSL
{MONITOR_REQ_MODULI, 0, mm_answer_moduli},
#endif
@@ -290,6 +299,10 @@ monitor_child_preauth(struct ssh *ssh, s
/* Permit requests for moduli and signatures */
monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
+#ifdef GSSAPI
+ /* and for the GSSAPI key exchange */
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
+#endif
/* The first few requests do not require asynchronous access */
while (!authenticated) {
@@ -401,6 +414,10 @@ monitor_child_postauth(struct ssh *ssh,
monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
+#ifdef GSSAPI
+ /* and for the GSSAPI key exchange */
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
+#endif
if (auth_opts->permit_pty_flag) {
monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
@@ -1730,6 +1747,17 @@ monitor_apply_keystate(struct ssh *ssh,
# ifdef OPENSSL_HAS_ECC
kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
# endif
+# ifdef GSSAPI
+ if (options.gss_keyex) {
+ kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
+ kex->kex[KEX_GSS_GRP14_SHA256] = kexgss_server;
+ kex->kex[KEX_GSS_GRP16_SHA512] = kexgss_server;
+ kex->kex[KEX_GSS_GEX_SHA1] = kexgssgex_server;
+ kex->kex[KEX_GSS_NISTP256_SHA256] = kexgss_server;
+ kex->kex[KEX_GSS_C25519_SHA256] = kexgss_server;
+ }
+# endif
#endif /* WITH_OPENSSL */
kex->kex[KEX_C25519_SHA256] = kex_gen_server;
kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
@@ -1822,8 +1850,8 @@ mm_answer_gss_setup_ctx(struct ssh *ssh,
u_char *p;
int r;
- if (!options.gss_authentication)
- fatal_f("GSSAPI authentication not enabled");
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal_f("GSSAPI not enabled");
if ((r = sshbuf_get_string(m, &p, &len)) != 0)
fatal_fr(r, "parse");
@@ -1855,8 +1883,8 @@ mm_answer_gss_accept_ctx(struct ssh *ssh
OM_uint32 flags = 0; /* GSI needs this */
int r;
- if (!options.gss_authentication)
- fatal_f("GSSAPI authentication not enabled");
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal_f("GSSAPI not enabled");
if ((r = ssh_gssapi_get_buffer_desc(m, &in)) != 0)
fatal_fr(r, "ssh_gssapi_get_buffer_desc");
@@ -1876,6 +1904,7 @@ mm_answer_gss_accept_ctx(struct ssh *ssh
monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSIGN, 1);
}
return (0);
}
@@ -1887,8 +1916,8 @@ mm_answer_gss_checkmic(struct ssh *ssh,
OM_uint32 ret;
int r;
- if (!options.gss_authentication)
- fatal_f("GSSAPI authentication not enabled");
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal_f("GSSAPI not enabled");
if ((r = ssh_gssapi_get_buffer_desc(m, &gssbuf)) != 0 ||
(r = ssh_gssapi_get_buffer_desc(m, &mic)) != 0)
@@ -1914,13 +1943,17 @@ mm_answer_gss_checkmic(struct ssh *ssh,
int
mm_answer_gss_userok(struct ssh *ssh, int sock, struct sshbuf *m)
{
- int r, authenticated;
+ int r, authenticated, kex;
const char *displayname;
- if (!options.gss_authentication)
- fatal_f("GSSAPI authentication not enabled");
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal_f("GSSAPI not enabled");
- authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
+ if ((r = sshbuf_get_u32(m, &kex)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ authenticated = authctxt->valid &&
+ ssh_gssapi_userok(authctxt->user, authctxt->pw, kex);
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, authenticated)) != 0)
@@ -1929,7 +1962,11 @@ mm_answer_gss_userok(struct ssh *ssh, in
debug3_f("sending result %d", authenticated);
mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
- auth_method = "gssapi-with-mic";
+ if (kex) {
+ auth_method = "gssapi-keyex";
+ } else {
+ auth_method = "gssapi-with-mic";
+ }
if ((displayname = ssh_gssapi_displayname()) != NULL)
auth2_record_info(authctxt, "%s", displayname);
@@ -1937,5 +1974,85 @@ mm_answer_gss_userok(struct ssh *ssh, in
/* Monitor loop will terminate if authenticated */
return (authenticated);
}
+
+int
+mm_answer_gss_sign(struct ssh *ssh, int socket, struct sshbuf *m)
+{
+ gss_buffer_desc data;
+ gss_buffer_desc hash = GSS_C_EMPTY_BUFFER;
+ OM_uint32 major, minor;
+ size_t len;
+ u_char *p = NULL;
+ int r;
+
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal("%s: GSSAPI not enabled", __func__);
+
+ if ((r = sshbuf_get_string(m, &p, &len)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ data.value = p;
+ data.length = len;
+ /* Lengths of SHA-1, SHA-256 and SHA-512 hashes that are used */
+ if (data.length != 20 && data.length != 32 && data.length != 64)
+ fatal("%s: data length incorrect: %d", __func__,
+ (int) data.length);
+
+ /* Save the session ID on the first time around */
+ if (session_id2_len == 0) {
+ session_id2_len = data.length;
+ session_id2 = xmalloc(session_id2_len);
+ memcpy(session_id2, data.value, session_id2_len);
+ }
+ major = ssh_gssapi_sign(gsscontext, &data, &hash);
+
+ free(data.value);
+
+ sshbuf_reset(m);
+
+ if ((r = sshbuf_put_u32(m, major)) != 0 ||
+ (r = sshbuf_put_string(m, hash.value, hash.length)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ mm_request_send(socket, MONITOR_ANS_GSSSIGN, m);
+
+ gss_release_buffer(&minor, &hash);
+
+ /* Turn on getpwnam permissions */
+ monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
+
+ /* And credential updating, for when rekeying */
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSUPCREDS, 1);
+
+ return (0);
+}
+
+int
+mm_answer_gss_updatecreds(struct ssh *ssh, int socket, struct sshbuf *m) {
+ ssh_gssapi_ccache store;
+ int r, ok;
+
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal("%s: GSSAPI not enabled", __func__);
+
+ if ((r = sshbuf_get_string(m, (u_char **)&store.filename, NULL)) != 0 ||
+ (r = sshbuf_get_string(m, (u_char **)&store.envvar, NULL)) != 0 ||
+ (r = sshbuf_get_string(m, (u_char **)&store.envval, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ ok = ssh_gssapi_update_creds(&store);
+
+ free(store.filename);
+ free(store.envvar);
+ free(store.envval);
+
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, ok)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ mm_request_send(socket, MONITOR_ANS_GSSUPCREDS, m);
+
+ return(0);
+}
+
#endif /* GSSAPI */
Index: openssh-8.8p1/monitor.h
===================================================================
--- openssh-8.8p1.orig/monitor.h
+++ openssh-8.8p1/monitor.h
@@ -63,6 +63,8 @@ enum monitor_reqtype {
MONITOR_REQ_PAM_FREE_CTX = 110, MONITOR_ANS_PAM_FREE_CTX = 111,
MONITOR_REQ_AUDIT_EVENT = 112, MONITOR_REQ_AUDIT_COMMAND = 113,
+ MONITOR_REQ_GSSSIGN = 150, MONITOR_ANS_GSSSIGN = 151,
+ MONITOR_REQ_GSSUPCREDS = 152, MONITOR_ANS_GSSUPCREDS = 153,
};
struct ssh;
Index: openssh-8.8p1/monitor_wrap.c
===================================================================
--- openssh-8.8p1.orig/monitor_wrap.c
+++ openssh-8.8p1/monitor_wrap.c
@@ -999,13 +999,15 @@ mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss
}
int
-mm_ssh_gssapi_userok(char *user)
+mm_ssh_gssapi_userok(char *user, struct passwd *pw, int kex)
{
struct sshbuf *m;
int r, authenticated = 0;
if ((m = sshbuf_new()) == NULL)
fatal_f("sshbuf_new failed");
+ if ((r = sshbuf_put_u32(m, kex)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m);
mm_request_receive_expect(pmonitor->m_recvfd,
@@ -1018,4 +1020,57 @@ mm_ssh_gssapi_userok(char *user)
debug3_f("user %sauthenticated", authenticated ? "" : "not ");
return (authenticated);
}
+
+OM_uint32
+mm_ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *data, gss_buffer_desc *hash)
+{
+ struct sshbuf *m;
+ OM_uint32 major;
+ int r;
+
+ if ((m = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+ if ((r = sshbuf_put_string(m, data->value, data->length)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSIGN, m);
+ mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSIGN, m);
+
+ if ((r = sshbuf_get_u32(m, &major)) != 0 ||
+ (r = ssh_gssapi_get_buffer_desc(m, hash)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ sshbuf_free(m);
+
+ return (major);
+}
+
+int
+mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *store)
+{
+ struct sshbuf *m;
+ int r, ok;
+
+ if ((m = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+
+ if ((r = sshbuf_put_cstring(m,
+ store->filename ? store->filename : "")) != 0 ||
+ (r = sshbuf_put_cstring(m,
+ store->envvar ? store->envvar : "")) != 0 ||
+ (r = sshbuf_put_cstring(m,
+ store->envval ? store->envval : "")) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUPCREDS, m);
+ mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUPCREDS, m);
+
+ if ((r = sshbuf_get_u32(m, &ok)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ sshbuf_free(m);
+
+ return (ok);
+}
+
#endif /* GSSAPI */
Index: openssh-8.8p1/monitor_wrap.h
===================================================================
--- openssh-8.8p1.orig/monitor_wrap.h
+++ openssh-8.8p1/monitor_wrap.h
@@ -65,8 +65,10 @@ int mm_sshkey_verify(const struct sshkey
OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *,
gss_buffer_desc *, gss_buffer_desc *, OM_uint32 *);
-int mm_ssh_gssapi_userok(char *user);
+int mm_ssh_gssapi_userok(char *user, struct passwd *, int kex);
OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
+OM_uint32 mm_ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
+int mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *);
#endif
#ifdef USE_PAM
Index: openssh-8.8p1/readconf.c
===================================================================
--- openssh-8.8p1.orig/readconf.c
+++ openssh-8.8p1/readconf.c
@@ -67,6 +67,7 @@
#include "uidswap.h"
#include "myproposal.h"
#include "digest.h"
+#include "ssh-gss.h"
#include "fips.h"
@@ -163,6 +164,8 @@ typedef enum {
oClearAllForwardings, oNoHostAuthenticationForLocalhost,
oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
oAddressFamily, oGssAuthentication, oGssDelegateCreds,
+ oGssTrustDns, oGssKeyEx, oGssClientIdentity, oGssRenewalRekey,
+ oGssServerIdentity, oGssKexAlgorithms,
oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
oSendEnv, oSetEnv, oControlPath, oControlMaster, oControlPersist,
oHashKnownHosts,
@@ -208,10 +211,22 @@ static struct {
/* Sometimes-unsupported options */
#if defined(GSSAPI)
{ "gssapiauthentication", oGssAuthentication },
+ { "gssapikeyexchange", oGssKeyEx },
{ "gssapidelegatecredentials", oGssDelegateCreds },
+ { "gssapitrustdns", oGssTrustDns },
+ { "gssapiclientidentity", oGssClientIdentity },
+ { "gssapiserveridentity", oGssServerIdentity },
+ { "gssapirenewalforcesrekey", oGssRenewalRekey },
+ { "gssapikexalgorithms", oGssKexAlgorithms },
# else
{ "gssapiauthentication", oUnsupported },
+ { "gssapikeyexchange", oUnsupported },
{ "gssapidelegatecredentials", oUnsupported },
+ { "gssapitrustdns", oUnsupported },
+ { "gssapiclientidentity", oUnsupported },
+ { "gssapiserveridentity", oUnsupported },
+ { "gssapirenewalforcesrekey", oUnsupported },
+ { "gssapikexalgorithms", oUnsupported },
#endif
#ifdef ENABLE_PKCS11
{ "pkcs11provider", oPKCS11Provider },
@@ -1115,10 +1130,42 @@ parse_time:
intptr = &options->gss_authentication;
goto parse_flag;
+ case oGssKeyEx:
+ intptr = &options->gss_keyex;
+ goto parse_flag;
+
case oGssDelegateCreds:
intptr = &options->gss_deleg_creds;
goto parse_flag;
+ case oGssTrustDns:
+ intptr = &options->gss_trust_dns;
+ goto parse_flag;
+
+ case oGssClientIdentity:
+ charptr = &options->gss_client_identity;
+ goto parse_string;
+
+ case oGssServerIdentity:
+ charptr = &options->gss_server_identity;
+ goto parse_string;
+
+ case oGssRenewalRekey:
+ intptr = &options->gss_renewal_rekey;
+ goto parse_flag;
+
+ case oGssKexAlgorithms:
+ arg = argv_next(&ac, &av);
+ if (!arg || *arg == '\0')
+ fatal("%.200s line %d: Missing argument.",
+ filename, linenum);
+ if (!kex_gss_names_valid(arg))
+ fatal("%.200s line %d: Bad GSSAPI KexAlgorithms '%s'.",
+ filename, linenum, arg ? arg : "<NONE>");
+ if (*activep && options->gss_kex_algorithms == NULL)
+ options->gss_kex_algorithms = xstrdup(arg);
+ break;
+
case oBatchMode:
intptr = &options->batch_mode;
goto parse_flag;
@@ -2352,7 +2399,13 @@ initialize_options(Options * options)
options->fwd_opts.streamlocal_bind_unlink = -1;
options->pubkey_authentication = -1;
options->gss_authentication = -1;
+ options->gss_keyex = -1;
options->gss_deleg_creds = -1;
+ options->gss_trust_dns = -1;
+ options->gss_renewal_rekey = -1;
+ options->gss_client_identity = NULL;
+ options->gss_server_identity = NULL;
+ options->gss_kex_algorithms = NULL;
options->password_authentication = -1;
options->kbd_interactive_authentication = -1;
options->kbd_interactive_devices = NULL;
@@ -2509,8 +2562,18 @@ fill_default_options(Options * options)
options->pubkey_authentication = 1;
if (options->gss_authentication == -1)
options->gss_authentication = 0;
+ if (options->gss_keyex == -1)
+ options->gss_keyex = 0;
if (options->gss_deleg_creds == -1)
options->gss_deleg_creds = 0;
+ if (options->gss_trust_dns == -1)
+ options->gss_trust_dns = 0;
+ if (options->gss_renewal_rekey == -1)
+ options->gss_renewal_rekey = 0;
+#ifdef GSSAPI
+ if (options->gss_kex_algorithms == NULL)
+ options->gss_kex_algorithms = strdup(GSS_KEX_DEFAULT_KEX);
+#endif
if (options->password_authentication == -1)
options->password_authentication = 1;
if (options->kbd_interactive_authentication == -1)
@@ -3306,7 +3369,14 @@ dump_client_config(Options *o, const cha
dump_cfg_fmtint(oGatewayPorts, o->fwd_opts.gateway_ports);
#ifdef GSSAPI
dump_cfg_fmtint(oGssAuthentication, o->gss_authentication);
+ dump_cfg_fmtint(oGssKeyEx, o->gss_keyex);
dump_cfg_fmtint(oGssDelegateCreds, o->gss_deleg_creds);
+ dump_cfg_fmtint(oGssTrustDns, o->gss_trust_dns);
+ dump_cfg_fmtint(oGssRenewalRekey, o->gss_renewal_rekey);
+ dump_cfg_string(oGssClientIdentity, o->gss_client_identity);
+ dump_cfg_string(oGssServerIdentity, o->gss_server_identity);
+ dump_cfg_string(oGssKexAlgorithms, o->gss_kex_algorithms ?
+ o->gss_kex_algorithms : GSS_KEX_DEFAULT_KEX);
#endif /* GSSAPI */
dump_cfg_fmtint(oHashKnownHosts, o->hash_known_hosts);
dump_cfg_fmtint(oHostbasedAuthentication, o->hostbased_authentication);
Index: openssh-8.8p1/readconf.h
===================================================================
--- openssh-8.8p1.orig/readconf.h
+++ openssh-8.8p1/readconf.h
@@ -39,7 +39,13 @@ typedef struct {
int pubkey_authentication; /* Try ssh2 pubkey authentication. */
int hostbased_authentication; /* ssh2's rhosts_rsa */
int gss_authentication; /* Try GSS authentication */
+ int gss_keyex; /* Try GSS key exchange */
int gss_deleg_creds; /* Delegate GSS credentials */
+ int gss_trust_dns; /* Trust DNS for GSS canonicalization */
+ int gss_renewal_rekey; /* Credential renewal forces rekey */
+ char *gss_client_identity; /* Principal to initiate GSSAPI with */
+ char *gss_server_identity; /* GSSAPI target principal */
+ char *gss_kex_algorithms; /* GSSAPI kex methods to be offered by client. */
int password_authentication; /* Try password
* authentication. */
int kbd_interactive_authentication; /* Try keyboard-interactive auth. */
Index: openssh-8.8p1/servconf.c
===================================================================
--- openssh-8.8p1.orig/servconf.c
+++ openssh-8.8p1/servconf.c
@@ -70,6 +70,7 @@
#include "auth.h"
#include "myproposal.h"
#include "digest.h"
+#include "ssh-gss.h"
#include "fips.h"
static void add_listen_addr(ServerOptions *, const char *,
@@ -138,8 +139,11 @@ initialize_server_options(ServerOptions
options->kerberos_ticket_cleanup = -1;
options->kerberos_get_afs_token = -1;
options->gss_authentication=-1;
+ options->gss_keyex = -1;
options->gss_cleanup_creds = -1;
options->gss_strict_acceptor = -1;
+ options->gss_store_rekey = -1;
+ options->gss_kex_algorithms = NULL;
options->password_authentication = -1;
options->kbd_interactive_authentication = -1;
options->permit_empty_passwd = -1;
@@ -379,10 +383,18 @@ fill_default_server_options(ServerOption
options->kerberos_get_afs_token = 0;
if (options->gss_authentication == -1)
options->gss_authentication = 0;
+ if (options->gss_keyex == -1)
+ options->gss_keyex = 0;
if (options->gss_cleanup_creds == -1)
options->gss_cleanup_creds = 1;
if (options->gss_strict_acceptor == -1)
options->gss_strict_acceptor = 1;
+ if (options->gss_store_rekey == -1)
+ options->gss_store_rekey = 0;
+#ifdef GSSAPI
+ if (options->gss_kex_algorithms == NULL)
+ options->gss_kex_algorithms = strdup(GSS_KEX_DEFAULT_KEX);
+#endif
if (options->password_authentication == -1)
options->password_authentication = 1;
if (options->kbd_interactive_authentication == -1)
@@ -530,6 +542,7 @@ typedef enum {
sHostKeyAlgorithms, sPerSourceMaxStartups, sPerSourceNetBlockSize,
sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile,
sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor,
+ sGssKeyEx, sGssKexAlgorithms, sGssStoreRekey,
sAcceptEnv, sSetEnv, sPermitTunnel,
sMatch, sPermitOpen, sPermitListen, sForceCommand, sChrootDirectory,
sUsePrivilegeSeparation, sAllowAgentForwarding,
@@ -613,12 +626,22 @@ static struct {
#ifdef GSSAPI
{ "gssapiauthentication", sGssAuthentication, SSHCFG_ALL },
{ "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL },
+ { "gssapicleanupcreds", sGssCleanupCreds, SSHCFG_GLOBAL },
{ "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL },
+ { "gssapikeyexchange", sGssKeyEx, SSHCFG_GLOBAL },
+ { "gssapistorecredentialsonrekey", sGssStoreRekey, SSHCFG_GLOBAL },
+ { "gssapikexalgorithms", sGssKexAlgorithms, SSHCFG_GLOBAL },
#else
{ "gssapiauthentication", sUnsupported, SSHCFG_ALL },
{ "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL },
+ { "gssapicleanupcreds", sUnsupported, SSHCFG_GLOBAL },
{ "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL },
+ { "gssapikeyexchange", sUnsupported, SSHCFG_GLOBAL },
+ { "gssapistorecredentialsonrekey", sUnsupported, SSHCFG_GLOBAL },
+ { "gssapikexalgorithms", sUnsupported, SSHCFG_GLOBAL },
#endif
+ { "gssusesessionccache", sUnsupported, SSHCFG_GLOBAL },
+ { "gssapiusesessioncredcache", sUnsupported, SSHCFG_GLOBAL },
{ "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL },
{ "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL },
{ "challengeresponseauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL }, /* alias */
@@ -1605,6 +1628,10 @@ process_server_config_line_depth(ServerO
intptr = &options->gss_authentication;
goto parse_flag;
+ case sGssKeyEx:
+ intptr = &options->gss_keyex;
+ goto parse_flag;
+
case sGssCleanupCreds:
intptr = &options->gss_cleanup_creds;
goto parse_flag;
@@ -1613,6 +1640,22 @@ process_server_config_line_depth(ServerO
intptr = &options->gss_strict_acceptor;
goto parse_flag;
+ case sGssStoreRekey:
+ intptr = &options->gss_store_rekey;
+ goto parse_flag;
+
+ case sGssKexAlgorithms:
+ arg = argv_next(&ac, &av);
+ if (!arg || *arg == '\0')
+ fatal("%.200s line %d: Missing argument.",
+ filename, linenum);
+ if (!kex_gss_names_valid(arg))
+ fatal("%.200s line %d: Bad GSSAPI KexAlgorithms '%s'.",
+ filename, linenum, arg ? arg : "<NONE>");
+ if (*activep && options->gss_kex_algorithms == NULL)
+ options->gss_kex_algorithms = xstrdup(arg);
+ break;
+
case sPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
@@ -2921,6 +2964,10 @@ dump_config(ServerOptions *o)
#ifdef GSSAPI
dump_cfg_fmtint(sGssAuthentication, o->gss_authentication);
dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds);
+ dump_cfg_fmtint(sGssKeyEx, o->gss_keyex);
+ dump_cfg_fmtint(sGssStrictAcceptor, o->gss_strict_acceptor);
+ dump_cfg_fmtint(sGssStoreRekey, o->gss_store_rekey);
+ dump_cfg_string(sGssKexAlgorithms, o->gss_kex_algorithms);
#endif
dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication);
dump_cfg_fmtint(sKbdInteractiveAuthentication,
Index: openssh-8.8p1/servconf.h
===================================================================
--- openssh-8.8p1.orig/servconf.h
+++ openssh-8.8p1/servconf.h
@@ -141,8 +141,11 @@ typedef struct {
int kerberos_get_afs_token; /* If true, try to get AFS token if
* authenticated with Kerberos. */
int gss_authentication; /* If true, permit GSSAPI authentication */
+ int gss_keyex; /* If true, permit GSSAPI key exchange */
int gss_cleanup_creds; /* If true, destroy cred cache on logout */
int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */
+ int gss_store_rekey;
+ char *gss_kex_algorithms; /* GSSAPI kex methods to be offered by client. */
int password_authentication; /* If true, permit password
* authentication. */
int kbd_interactive_authentication; /* If true, permit */
Index: openssh-8.8p1/session.c
===================================================================
--- openssh-8.8p1.orig/session.c
+++ openssh-8.8p1/session.c
@@ -2709,13 +2709,19 @@ do_cleanup(struct ssh *ssh, Authctxt *au
#ifdef KRB5
if (options.kerberos_ticket_cleanup &&
- authctxt->krb5_ctx)
+ authctxt->krb5_ctx) {
+ temporarily_use_uid(authctxt->pw);
krb5_cleanup_proc(authctxt);
+ restore_uid();
+ }
#endif
#ifdef GSSAPI
- if (options.gss_cleanup_creds)
+ if (options.gss_cleanup_creds) {
+ temporarily_use_uid(authctxt->pw);
ssh_gssapi_cleanup_creds();
+ restore_uid();
+ }
#endif
/* remove agent socket */
Index: openssh-8.8p1/ssh-gss.h
===================================================================
--- openssh-8.8p1.orig/ssh-gss.h
+++ openssh-8.8p1/ssh-gss.h
@@ -1,6 +1,6 @@
/* $OpenBSD: ssh-gss.h,v 1.15 2021/01/27 10:05:28 djm Exp $ */
/*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -61,10 +61,30 @@
#define SSH_GSS_OIDTYPE 0x06
+#define SSH2_MSG_KEXGSS_INIT 30
+#define SSH2_MSG_KEXGSS_CONTINUE 31
+#define SSH2_MSG_KEXGSS_COMPLETE 32
+#define SSH2_MSG_KEXGSS_HOSTKEY 33
+#define SSH2_MSG_KEXGSS_ERROR 34
+#define SSH2_MSG_KEXGSS_GROUPREQ 40
+#define SSH2_MSG_KEXGSS_GROUP 41
+#define KEX_GSS_GRP1_SHA1_ID "gss-group1-sha1-"
+#define KEX_GSS_GRP14_SHA1_ID "gss-group14-sha1-"
+#define KEX_GSS_GRP14_SHA256_ID "gss-group14-sha256-"
+#define KEX_GSS_GRP16_SHA512_ID "gss-group16-sha512-"
+#define KEX_GSS_GEX_SHA1_ID "gss-gex-sha1-"
+#define KEX_GSS_NISTP256_SHA256_ID "gss-nistp256-sha256-"
+#define KEX_GSS_C25519_SHA256_ID "gss-curve25519-sha256-"
+
+#define GSS_KEX_DEFAULT_KEX \
+ KEX_GSS_GEX_SHA1_ID "," \
+ KEX_GSS_GRP14_SHA1_ID
+
typedef struct {
char *filename;
char *envvar;
char *envval;
+ struct passwd *owner;
void *data;
} ssh_gssapi_ccache;
@@ -72,8 +92,11 @@ typedef struct {
gss_buffer_desc displayname;
gss_buffer_desc exportedname;
gss_cred_id_t creds;
+ gss_name_t name;
struct ssh_gssapi_mech_struct *mech;
ssh_gssapi_ccache store;
+ int used;
+ int updated;
} ssh_gssapi_client;
typedef struct ssh_gssapi_mech_struct {
@@ -84,6 +107,7 @@ typedef struct ssh_gssapi_mech_struct {
int (*userok) (ssh_gssapi_client *, char *);
int (*localname) (ssh_gssapi_client *, char **);
void (*storecreds) (ssh_gssapi_client *);
+ int (*updatecreds) (ssh_gssapi_ccache *, ssh_gssapi_client *);
} ssh_gssapi_mech;
typedef struct {
@@ -94,10 +118,11 @@ typedef struct {
gss_OID oid; /* client */
gss_cred_id_t creds; /* server */
gss_name_t client; /* server */
- gss_cred_id_t client_creds; /* server */
+ gss_cred_id_t client_creds; /* both */
} Gssctxt;
extern ssh_gssapi_mech *supported_mechs[];
+extern Gssctxt *gss_kex_context;
int ssh_gssapi_check_oid(Gssctxt *, void *, size_t);
void ssh_gssapi_set_oid_data(Gssctxt *, void *, size_t);
@@ -109,6 +134,7 @@ OM_uint32 ssh_gssapi_test_oid_supported(
struct sshbuf;
int ssh_gssapi_get_buffer_desc(struct sshbuf *, gss_buffer_desc *);
+int ssh_gssapi_sshpkt_get_buffer_desc(struct ssh *, gss_buffer_desc *);
OM_uint32 ssh_gssapi_import_name(Gssctxt *, const char *);
OM_uint32 ssh_gssapi_init_ctx(Gssctxt *, int,
@@ -123,17 +149,33 @@ void ssh_gssapi_delete_ctx(Gssctxt **);
OM_uint32 ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
void ssh_gssapi_buildmic(struct sshbuf *, const char *,
const char *, const char *, const struct sshbuf *);
-int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *);
+int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *, const char *);
+OM_uint32 ssh_gssapi_client_identity(Gssctxt *, const char *);
+int ssh_gssapi_credentials_updated(Gssctxt *);
/* In the server */
+typedef int ssh_gssapi_check_fn(Gssctxt **, gss_OID, const char *,
+ const char *);
+char *ssh_gssapi_client_mechanisms(const char *, const char *, const char *);
+char *ssh_gssapi_kex_mechs(gss_OID_set, ssh_gssapi_check_fn *, const char *,
+ const char *, const char *);
+gss_OID ssh_gssapi_id_kex(Gssctxt *, char *, int);
+int ssh_gssapi_server_check_mech(Gssctxt **,gss_OID, const char *,
+ const char *);
OM_uint32 ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
-int ssh_gssapi_userok(char *name);
+int ssh_gssapi_userok(char *, struct passwd *, int kex);
OM_uint32 ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
void ssh_gssapi_do_child(char ***, u_int *);
void ssh_gssapi_cleanup_creds(void);
void ssh_gssapi_storecreds(void);
const char *ssh_gssapi_displayname(void);
+char *ssh_gssapi_server_mechanisms(void);
+int ssh_gssapi_oid_table_ok(void);
+
+int ssh_gssapi_update_creds(ssh_gssapi_ccache *store);
+void ssh_gssapi_rekey_creds(void);
+
#endif /* GSSAPI */
#endif /* _SSH_GSS_H */
Index: openssh-8.8p1/ssh.1
===================================================================
--- openssh-8.8p1.orig/ssh.1
+++ openssh-8.8p1/ssh.1
@@ -530,7 +530,13 @@ For full details of the options listed b
.It GatewayPorts
.It GlobalKnownHostsFile
.It GSSAPIAuthentication
+.It GSSAPIKeyExchange
+.It GSSAPIClientIdentity
.It GSSAPIDelegateCredentials
+.It GSSAPIKexAlgorithms
+.It GSSAPIRenewalForcesRekey
+.It GSSAPIServerIdentity
+.It GSSAPITrustDns
.It HashKnownHosts
.It Host
.It HostbasedAcceptedAlgorithms
@@ -607,6 +613,8 @@ flag),
(supported message integrity codes),
.Ar kex
(key exchange algorithms),
+.Ar kex-gss
+(GSSAPI key exchange algorithms),
.Ar key
(key types),
.Ar key-cert
Index: openssh-8.8p1/ssh.c
===================================================================
--- openssh-8.8p1.orig/ssh.c
+++ openssh-8.8p1/ssh.c
@@ -781,6 +781,8 @@ main(int ac, char **av)
else if (strcmp(optarg, "kex") == 0 ||
strcasecmp(optarg, "KexAlgorithms") == 0)
cp = kex_alg_list('\n');
+ else if (strcmp(optarg, "kex-gss") == 0)
+ cp = kex_gss_alg_list('\n');
else if (strcmp(optarg, "key") == 0)
cp = sshkey_alg_list(0, 0, 0, '\n');
else if (strcmp(optarg, "key-cert") == 0)
@@ -807,7 +809,7 @@ main(int ac, char **av)
cp[n] = '\n';
} else if (strcmp(optarg, "help") == 0) {
cp = xstrdup(
- "cipher\ncipher-auth\ncompression\nkex\n"
+ "cipher\ncipher-auth\ncompression\nkex\nkex-gss\n"
"key\nkey-cert\nkey-plain\nkey-sig\nmac\n"
"protocol-version\nsig");
}
Index: openssh-8.8p1/ssh_config
===================================================================
--- openssh-8.8p1.orig/ssh_config
+++ openssh-8.8p1/ssh_config
@@ -40,6 +40,8 @@ Host *
# HostbasedAuthentication no
# GSSAPIAuthentication no
# GSSAPIDelegateCredentials no
+# GSSAPIKeyExchange no
+# GSSAPITrustDNS no
# BatchMode no
# CheckHostIP yes
# AddressFamily any
Index: openssh-8.8p1/ssh_config.5
===================================================================
--- openssh-8.8p1.orig/ssh_config.5
+++ openssh-8.8p1/ssh_config.5
@@ -835,10 +835,67 @@ The default is
Specifies whether user authentication based on GSSAPI is allowed.
The default is
.Cm no .
+.It Cm GSSAPIClientIdentity
+If set, specifies the GSSAPI client identity that ssh should use when
+connecting to the server. The default is unset, which means that the default
+identity will be used.
.It Cm GSSAPIDelegateCredentials
Forward (delegate) credentials to the server.
The default is
.Cm no .
+.It Cm GSSAPIKeyExchange
+Specifies whether key exchange based on GSSAPI may be used. When using
+GSSAPI key exchange the server need not have a host key.
+The default is
+.Dq no .
+.It Cm GSSAPIRenewalForcesRekey
+If set to
+.Dq yes
+then renewal of the client's GSSAPI credentials will force the rekeying of the
+ssh connection. With a compatible server, this will delegate the renewed
+credentials to a session on the server.
+.Pp
+Checks are made to ensure that credentials are only propagated when the new
+credentials match the old ones on the originating client and where the
+receiving server still has the old set in its cache.
+.Pp
+The default is
+.Dq no .
+.Pp
+For this to work
+.Cm GSSAPIKeyExchange
+needs to be enabled in the server and also used by the client.
+.It Cm GSSAPIServerIdentity
+If set, specifies the GSSAPI server identity that ssh should expect when
+connecting to the server. The default is unset, which means that the
+expected GSSAPI server identity will be determined from the target
+hostname.
+.It Cm GSSAPITrustDns
+Set to
+.Dq yes
+to indicate that the DNS is trusted to securely canonicalize
+the name of the host being connected to. If
+.Dq no ,
+the hostname entered on the
+command line will be passed untouched to the GSSAPI library.
+The default is
+.Dq no .
+.It Cm GSSAPIKexAlgorithms
+The list of key exchange algorithms that are offered for GSSAPI
+key exchange. Possible values are
+.Bd -literal -offset 3n
+gss-gex-sha1-,
+gss-group1-sha1-,
+gss-group14-sha1-,
+gss-group14-sha256-,
+gss-group16-sha512-,
+gss-nistp256-sha256-,
+gss-curve25519-sha256-
+.Ed
+.Pp
+The default is
+.Dq gss-gex-sha1-,gss-group14-sha1- .
+This option only applies to protocol version 2 connections using GSSAPI.
.It Cm HashKnownHosts
Indicates that
.Xr ssh 1
Index: openssh-8.8p1/sshconnect2.c
===================================================================
--- openssh-8.8p1.orig/sshconnect2.c
+++ openssh-8.8p1/sshconnect2.c
@@ -81,8 +81,6 @@
#endif
/* import */
-extern char *client_version_string;
-extern char *server_version_string;
extern Options options;
/*
@@ -220,6 +218,11 @@ ssh_kex2(struct ssh *ssh, char *host, st
char *s, *all_key;
int r, use_known_hosts_order = 0;
+#if defined(GSSAPI) && defined(WITH_OPENSSL)
+ char *orig = NULL, *gss = NULL;
+ char *gss_host = NULL;
+#endif
+
xxx_host = host;
xxx_hostaddr = hostaddr;
xxx_conn_info = cinfo;
@@ -264,6 +267,35 @@ ssh_kex2(struct ssh *ssh, char *host, st
compat_pkalg_proposal(ssh, options.hostkeyalgorithms);
}
+#if defined(GSSAPI) && defined(WITH_OPENSSL)
+ if (options.gss_keyex) {
+ /* Add the GSSAPI mechanisms currently supported on this
+ * client to the key exchange algorithm proposal */
+ orig = myproposal[PROPOSAL_KEX_ALGS];
+
+ if (options.gss_server_identity)
+ gss_host = xstrdup(options.gss_server_identity);
+ else if (options.gss_trust_dns)
+ gss_host = remote_hostname(ssh);
+ else
+ gss_host = xstrdup(host);
+
+ gss = ssh_gssapi_client_mechanisms(gss_host,
+ options.gss_client_identity, options.gss_kex_algorithms);
+ if (gss) {
+ debug("Offering GSSAPI proposal: %s", gss);
+ xasprintf(&myproposal[PROPOSAL_KEX_ALGS],
+ "%s,%s", gss, orig);
+
+ /* If we've got GSSAPI algorithms, then we also support the
+ * 'null' hostkey, as a last resort */
+ orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS];
+ xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS],
+ "%s,null", orig);
+ }
+ }
+#endif
+
if (options.rekey_limit || options.rekey_interval)
ssh_packet_set_rekey_limits(ssh, options.rekey_limit,
options.rekey_interval);
@@ -282,16 +314,46 @@ ssh_kex2(struct ssh *ssh, char *host, st
# ifdef OPENSSL_HAS_ECC
ssh->kex->kex[KEX_ECDH_SHA2] = kex_gen_client;
# endif
-#endif
+# ifdef GSSAPI
+ if (options.gss_keyex) {
+ ssh->kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client;
+ ssh->kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client;
+ ssh->kex->kex[KEX_GSS_GRP14_SHA256] = kexgss_client;
+ ssh->kex->kex[KEX_GSS_GRP16_SHA512] = kexgss_client;
+ ssh->kex->kex[KEX_GSS_GEX_SHA1] = kexgssgex_client;
+ ssh->kex->kex[KEX_GSS_NISTP256_SHA256] = kexgss_client;
+ ssh->kex->kex[KEX_GSS_C25519_SHA256] = kexgss_client;
+ }
+# endif
+#endif /* WITH_OPENSSL */
ssh->kex->kex[KEX_C25519_SHA256] = kex_gen_client;
ssh->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_client;
ssh->kex->verify_host_key=&verify_host_key_callback;
+#if defined(GSSAPI) && defined(WITH_OPENSSL)
+ if (options.gss_keyex) {
+ ssh->kex->gss_deleg_creds = options.gss_deleg_creds;
+ ssh->kex->gss_trust_dns = options.gss_trust_dns;
+ ssh->kex->gss_client = options.gss_client_identity;
+ ssh->kex->gss_host = gss_host;
+ }
+#endif
+
ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &ssh->kex->done);
/* remove ext-info from the KEX proposals for rekeying */
myproposal[PROPOSAL_KEX_ALGS] =
compat_kex_proposal(ssh, options.kex_algorithms);
+#if defined(GSSAPI) && defined(WITH_OPENSSL)
+ /* repair myproposal after it was crumpled by the */
+ /* ext-info removal above */
+ if (gss) {
+ orig = myproposal[PROPOSAL_KEX_ALGS];
+ xasprintf(&myproposal[PROPOSAL_KEX_ALGS],
+ "%s,%s", gss, orig);
+ free(gss);
+ }
+#endif
if ((r = kex_prop2buf(ssh->kex->my, myproposal)) != 0)
fatal_r(r, "kex_prop2buf");
@@ -385,6 +447,7 @@ static int input_gssapi_response(int typ
static int input_gssapi_token(int type, u_int32_t, struct ssh *);
static int input_gssapi_error(int, u_int32_t, struct ssh *);
static int input_gssapi_errtok(int, u_int32_t, struct ssh *);
+static int userauth_gsskeyex(struct ssh *);
#endif
void userauth(struct ssh *, char *);
@@ -401,6 +464,11 @@ static char *authmethods_get(void);
Authmethod authmethods[] = {
#ifdef GSSAPI
+ {"gssapi-keyex",
+ userauth_gsskeyex,
+ NULL,
+ &options.gss_keyex,
+ NULL},
{"gssapi-with-mic",
userauth_gssapi,
userauth_gssapi_cleanup,
@@ -776,12 +844,23 @@ userauth_gssapi(struct ssh *ssh)
OM_uint32 min;
int r, ok = 0;
gss_OID mech = NULL;
+ char *gss_host;
+
+ if (options.gss_server_identity)
+ gss_host = xstrdup(options.gss_server_identity);
+ else if (options.gss_trust_dns)
+ gss_host = remote_hostname(ssh);
+ else
+ gss_host = xstrdup(authctxt->host);
/* Try one GSSAPI method at a time, rather than sending them all at
* once. */
if (authctxt->gss_supported_mechs == NULL)
- gss_indicate_mechs(&min, &authctxt->gss_supported_mechs);
+ if (GSS_ERROR(gss_indicate_mechs(&min, &authctxt->gss_supported_mechs))) {
+ free(gss_host);
+ return 0;
+ }
/* Check to see whether the mechanism is usable before we offer it */
while (authctxt->mech_tried < authctxt->gss_supported_mechs->count &&
@@ -790,13 +869,15 @@ userauth_gssapi(struct ssh *ssh)
elements[authctxt->mech_tried];
/* My DER encoding requires length<128 */
if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt,
- mech, authctxt->host)) {
+ mech, gss_host, options.gss_client_identity)) {
ok = 1; /* Mechanism works */
} else {
authctxt->mech_tried++;
}
}
+ free(gss_host);
+
if (!ok || mech == NULL)
return 0;
@@ -1037,6 +1118,55 @@ input_gssapi_error(int type, u_int32_t p
free(lang);
return r;
}
+
+int
+userauth_gsskeyex(struct ssh *ssh)
+{
+ struct sshbuf *b = NULL;
+ Authctxt *authctxt = ssh->authctxt;
+ gss_buffer_desc gssbuf;
+ gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
+ OM_uint32 ms;
+ int r;
+
+ static int attempt = 0;
+ if (attempt++ >= 1)
+ return (0);
+
+ if (gss_kex_context == NULL) {
+ debug("No valid Key exchange context");
+ return (0);
+ }
+
+ if ((b = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+
+ ssh_gssapi_buildmic(b, authctxt->server_user, authctxt->service,
+ "gssapi-keyex", ssh->kex->session_id);
+
+ if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
+ fatal("%s: sshbuf_mutable_ptr failed", __func__);
+ gssbuf.length = sshbuf_len(b);
+
+ if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) {
+ sshbuf_free(b);
+ return (0);
+ }
+
+ if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
+ (r = sshpkt_put_string(ssh, mic.value, mic.length)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal("%s: %s", __func__, ssh_err(r));
+
+ sshbuf_free(b);
+ gss_release_buffer(&ms, &mic);
+
+ return (1);
+}
+
#endif /* GSSAPI */
static int
Index: openssh-8.8p1/sshd.c
===================================================================
--- openssh-8.8p1.orig/sshd.c
+++ openssh-8.8p1/sshd.c
@@ -817,8 +817,8 @@ notify_hostkeys(struct ssh *ssh)
}
debug3_f("sent %u hostkeys", nkeys);
if (nkeys == 0)
- fatal_f("no hostkeys");
- if ((r = sshpkt_send(ssh)) != 0)
+ debug3("%s: no hostkeys", __func__);
+ else if ((r = sshpkt_send(ssh)) != 0)
sshpkt_fatal(ssh, r, "%s: send", __func__);
sshbuf_free(buf);
}
@@ -1912,7 +1912,8 @@ main(int ac, char **av)
free(fp);
}
accumulate_host_timing_secret(cfg, NULL);
- if (!sensitive_data.have_ssh2_key) {
+ /* The GSSAPI key exchange can run without a host key */
+ if (!sensitive_data.have_ssh2_key && !options.gss_keyex) {
logit("sshd: no hostkeys available -- exiting.");
exit(1);
}
@@ -2407,6 +2408,48 @@ do_ssh2_kex(struct ssh *ssh)
myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal(
ssh, list_hostkey_types());
+#if defined(GSSAPI) && defined(WITH_OPENSSL)
+ {
+ char *orig;
+ char *gss = NULL;
+ char *newstr = NULL;
+ orig = myproposal[PROPOSAL_KEX_ALGS];
+
+ /*
+ * If we don't have a host key, then there's no point advertising
+ * the other key exchange algorithms
+ */
+
+ if (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]) == 0)
+ orig = NULL;
+
+ if (options.gss_keyex)
+ gss = ssh_gssapi_server_mechanisms();
+ else
+ gss = NULL;
+
+ if (gss && orig)
+ xasprintf(&newstr, "%s,%s", gss, orig);
+ else if (gss)
+ newstr = gss;
+ else if (orig)
+ newstr = orig;
+
+ /*
+ * If we've got GSSAPI mechanisms, then we've got the 'null' host
+ * key alg, but we can't tell people about it unless its the only
+ * host key algorithm we support
+ */
+ if (gss && (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS])) == 0)
+ myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = "null";
+
+ if (newstr)
+ myproposal[PROPOSAL_KEX_ALGS] = newstr;
+ else
+ fatal("No supported key exchange algorithms");
+ }
+#endif
+
/* start key exchange */
if ((r = kex_setup(ssh, myproposal)) != 0)
fatal_r(r, "kex_setup");
@@ -2422,7 +2465,18 @@ do_ssh2_kex(struct ssh *ssh)
# ifdef OPENSSL_HAS_ECC
kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
# endif
-#endif
+# ifdef GSSAPI
+ if (options.gss_keyex) {
+ kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
+ kex->kex[KEX_GSS_GRP14_SHA256] = kexgss_server;
+ kex->kex[KEX_GSS_GRP16_SHA512] = kexgss_server;
+ kex->kex[KEX_GSS_GEX_SHA1] = kexgssgex_server;
+ kex->kex[KEX_GSS_NISTP256_SHA256] = kexgss_server;
+ kex->kex[KEX_GSS_C25519_SHA256] = kexgss_server;
+ }
+# endif
+#endif /* WITH_OPENSSL */
kex->kex[KEX_C25519_SHA256] = kex_gen_server;
kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
kex->load_host_public_key=&get_hostkey_public_by_type;
Index: openssh-8.8p1/sshd_config
===================================================================
--- openssh-8.8p1.orig/sshd_config
+++ openssh-8.8p1/sshd_config
@@ -69,6 +69,8 @@ AuthorizedKeysFile .ssh/authorized_keys
# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes
+#GSSAPIStrictAcceptorCheck yes
+#GSSAPIKeyExchange no
# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
Index: openssh-8.8p1/sshd_config.5
===================================================================
--- openssh-8.8p1.orig/sshd_config.5
+++ openssh-8.8p1/sshd_config.5
@@ -652,6 +652,11 @@ Specifies whether to automatically destr
on logout.
The default is
.Cm yes .
+.It Cm GSSAPIKeyExchange
+Specifies whether key exchange based on GSSAPI is allowed. GSSAPI key exchange
+doesn't rely on ssh keys to verify host identity.
+The default is
+.Cm no .
.It Cm GSSAPIStrictAcceptorCheck
Determines whether to be strict about the identity of the GSSAPI acceptor
a client authenticates against.
@@ -666,6 +671,31 @@ machine's default store.
This facility is provided to assist with operation on multi homed machines.
The default is
.Cm yes .
+.It Cm GSSAPIStoreCredentialsOnRekey
+Controls whether the user's GSSAPI credentials should be updated following a
+successful connection rekeying. This option can be used to accepted renewed
+or updated credentials from a compatible client. The default is
+.Dq no .
+.Pp
+For this to work
+.Cm GSSAPIKeyExchange
+needs to be enabled in the server and also used by the client.
+.It Cm GSSAPIKexAlgorithms
+The list of key exchange algorithms that are accepted by GSSAPI
+key exchange. Possible values are
+.Bd -literal -offset 3n
+gss-gex-sha1-,
+gss-group1-sha1-,
+gss-group14-sha1-,
+gss-group14-sha256-,
+gss-group16-sha512-,
+gss-nistp256-sha256-,
+gss-curve25519-sha256-
+.Ed
+.Pp
+The default is
+.Dq gss-gex-sha1-,gss-group14-sha1- .
+This option only applies to protocol version 2 connections using GSSAPI.
.It Cm HostbasedAcceptedAlgorithms
Specifies the signature algorithms that will be accepted for hostbased
authentication as a list of comma-separated patterns.
Index: openssh-8.8p1/sshkey.c
===================================================================
--- openssh-8.8p1.orig/sshkey.c
+++ openssh-8.8p1/sshkey.c
@@ -156,6 +156,7 @@ static const struct keytype keytypes[] =
KEY_ECDSA_SK_CERT, NID_X9_62_prime256v1, 1, 0 },
# endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
+ { "null", "null", NULL, KEY_NULL, 0, 0, 0 },
{ NULL, NULL, NULL, -1, -1, 0, 0 }
};
@@ -257,7 +258,7 @@ sshkey_alg_list(int certs_only, int plai
const struct keytype *kt;
for (kt = keytypes; kt->type != -1; kt++) {
- if (kt->name == NULL)
+ if (kt->name == NULL || kt->type == KEY_NULL)
continue;
if (!include_sigonly && kt->sigonly)
continue;
Index: openssh-8.8p1/sshkey.h
===================================================================
--- openssh-8.8p1.orig/sshkey.h
+++ openssh-8.8p1/sshkey.h
@@ -71,6 +71,7 @@ enum sshkey_types {
KEY_ECDSA_SK_CERT,
KEY_ED25519_SK,
KEY_ED25519_SK_CERT,
+ KEY_NULL,
KEY_UNSPEC
};
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