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openssh/openssh-7.7p1-fips_checks.patch
Marcus Meissner 3f6eda5c88 - Update to openssh 9.9p1: 
* No changes for askpass, see main package changelog for
    details.

- Update to openssh 9.9p1:
  = Future deprecation notice
  * OpenSSH plans to remove support for the DSA signature algorithm
    in early 2025. This release disables DSA by default at compile
    time. DSA, as specified in the SSHv2 protocol, is inherently
    weak - being limited to a 160 bit private key and use of the
    SHA1 digest. Its estimated security level is only 80 bits
    symmetric equivalent.
    OpenSSH has disabled DSA keys by default since 2015 but has
    retained run-time optional support for them. DSA was the only
    mandatory-to-implement algorithm in the SSHv2 RFCs, mostly
    because alternative algorithms were encumbered by patents when
    the SSHv2 protocol was specified.
    This has not been the case for decades at this point and better
    algorithms are well supported by all actively-maintained SSH
    implementations. We do not consider the costs of maintaining
    DSA in OpenSSH to be justified and hope that removing it from
    OpenSSH can accelerate its wider deprecation in supporting
    cryptography libraries.
  = Potentially-incompatible changes
  * ssh(1): remove support for pre-authentication compression.
    OpenSSH has only supported post-authentication compression in
    the server for some years. Compression before authentication
    significantly increases the attack surface of SSH servers and
    risks creating oracles that reveal information about
    information sent during authentication.

OBS-URL: https://build.opensuse.org/package/show/network/openssh?expand=0&rev=275
2024-09-25 08:42:29 +00:00

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# HG changeset patch
# Parent e9b69da9a0f8dca923f8fc2836b38fe6590c791a
#
# Simple implementation of FIPS 140-2 selfchecks. Use OpenSSL to generate and
# verify checksums of binaries. Any hash iused in OpenSSH can be used (MD5 would
# obviously be a poor choice, since OpenSSL would barf and abort immediately in
# FIPS mode). SHA-2 seems to be a reasonable choice.
#
# The logic of the checks is as follows: decide whether FIPS mode is mandated
# (either by checking /proc/sys/crypto/fips_enabled or environment variable
# SSH_FORCE_FIPS. In FIPS mode, checksums are required to match (inability to
# retrieve pre-calculated hash is a fatal error). In non-FIPS mode the checks
# still must be performed, unless the hashes are not installed. Thus if the hash
# file is not found (or the hash matches), proceed in non-FIPS mode and abort
# otherwise.
Index: openssh-8.8p1/fips-check.c
===================================================================
--- /dev/null
+++ openssh-8.8p1/fips-check.c
@@ -0,0 +1,34 @@
+#include "includes.h"
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "digest.h"
+#include "fips.h"
+
+#include <openssl/err.h>
+
+#define PROC_NAME_LEN 64
+
+static const char *argv0;
+
+void
+print_help_exit(int ev)
+{
+ fprintf(stderr, "%s <-c|-w> <file> <checksum_file>\n", argv0);
+ fprintf(stderr, " -c verify hash of 'file' against hash in 'checksum_file'\n");
+ fprintf(stderr, " -w write hash of 'file' into 'checksum_file'\n");
+ exit(ev);
+}
+
+int
+main(int argc, char **argv)
+{
+ fips_ssh_init();
+ return 0;
+}
Index: openssh-8.8p1/fips.c
===================================================================
--- openssh-8.8p1.orig/fips.c
+++ openssh-8.8p1/fips.c
@@ -35,30 +35,293 @@
#include "log.h"
#include "xmalloc.h"
+#include <errno.h>
+#include <fcntl.h>
#include <string.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
#include <openssl/crypto.h>
+#include <openssl/err.h>
+#include <openssl/hmac.h>
static int fips_state = -1;
+/* calculates HMAC of contents of a file given by filename using the hash
+ * algorithm specified by FIPS_HMAC_EVP in fips.h and placing the result into
+ * newly allacated memory - remember to free it when not needed anymore */
static int
-fips_check_required_env(void)
+hmac_file(const char *filename, u_char **hmac_out)
+{
+ int check = -1;
+ int fd;
+ struct stat fs;
+ void *hmap;
+ unsigned char *hmac;
+ unsigned char *hmac_rv = NULL;
+
+ hmac = xmalloc(FIPS_HMAC_LEN);
+
+ fd = open(filename, O_RDONLY);
+ if (-1 == fd)
+ goto bail_out;
+
+ if (-1 == fstat(fd, &fs))
+ goto bail_out;
+
+ hmap = mmap(NULL, fs.st_size, PROT_READ, MAP_SHARED, fd, 0);
+
+ if ((void *)(-1) != hmap) {
+ hmac_rv = HMAC(FIPS_HMAC_EVP(), FIPS_HMAC_KEY
+ , strlen(FIPS_HMAC_KEY), hmap, fs.st_size, hmac, NULL);
+ check = CHECK_OK;
+ munmap(hmap, fs.st_size);
+ }
+ close(fd);
+
+bail_out:
+ if (hmac_rv) {
+ check = CHECK_OK;
+ *hmac_out = hmac;
+ } else {
+ check = CHECK_FAIL;
+ *hmac_out = NULL;
+ free(hmac);
+ }
+ return check;
+}
+
+/* find pathname of binary of process with PID pid. exe is buffer expected to
+ * be capable of holding at least max_pathlen characters
+ */
+static int
+get_executable_path(pid_t pid, char *exe, int max_pathlen)
+{
+ char exe_sl[PROC_EXE_PATH_LEN];
+ int n;
+ int rv = -1;
+
+ n = snprintf(exe_sl, sizeof(exe_sl), "/proc/%u/exe", pid);
+ if ((n <= 10) || (n >= max_pathlen)) {
+ fatal("error compiling filename of link to executable");
+ }
+
+ exe[0] = 0;
+ n = readlink(exe_sl, exe, max_pathlen);
+ /* the file doesn't need to exist - procfs might not be mounted in
+ * chroot */
+ if (n == -1) {
+ rv = CHECK_MISSING;
+ } else {
+ if (n < max_pathlen) {
+ exe[n] = 0;
+ rv = CHECK_OK;
+ } else {
+ rv = CHECK_FAIL;
+ }
+ }
+ return rv;
+}
+
+/* Read HMAC from file chk, allocating enough memory to hold the HMAC and
+ * return it in *hmac.
+ * Remember to free() it when it's not needed anymore.
+ */
+static int
+read_hmac(const char *chk, u_char **hmac)
+{
+ int check = -1;
+ int fdh, n;
+ u_char *hmac_in;
+
+ *hmac = NULL;
+
+ fdh = open(chk, O_RDONLY);
+ if (-1 == fdh) {
+ switch (errno) {
+ case ENOENT:
+ check = CHECK_MISSING;
+ debug("fips: checksum file %s is missing\n", chk);
+ break;
+ default:
+ check = CHECK_FAIL;
+ debug("fips: ckecksum file %s not accessible\n", chk);
+ break;
+
+ }
+ goto bail_out;
+ }
+
+ hmac_in = xmalloc(FIPS_HMAC_LEN);
+
+ n = read(fdh, (void *)hmac_in, FIPS_HMAC_LEN);
+ if (FIPS_HMAC_LEN != n) {
+ debug("fips: unable to read whole checksum from checksum file\n");
+ free (hmac_in);
+ check = CHECK_FAIL;
+ } else {
+ check = CHECK_OK;
+ *hmac = hmac_in;
+ }
+bail_out:
+ return check;
+}
+
+static int
+fips_hmac_self(void)
+{
+ int check = -1;
+ u_char *hmac = NULL, *hmac_chk = NULL;
+ char *exe, *chk;
+
+ exe = xmalloc(PATH_MAX);
+ chk = xmalloc(PATH_MAX);
+
+ /* we will need to add the suffix and the null terminator */
+ check = get_executable_path(getpid(), exe
+ , PATH_MAX - strlen(CHECKSUM_SUFFIX) - 1);
+ if (CHECK_OK != check)
+ goto cleanup;
+
+ strncpy(chk, exe, PATH_MAX);
+ strlcat(chk, CHECKSUM_SUFFIX, PATH_MAX);
+
+ check = read_hmac(chk, &hmac_chk);
+ if (CHECK_OK != check)
+ goto cleanup;
+
+ check = hmac_file(exe, &hmac);
+ if (CHECK_OK != check)
+ goto cleanup;
+
+ check = memcmp(hmac, hmac_chk, FIPS_HMAC_LEN);
+ if (0 == check) {
+ check = CHECK_OK;
+ debug("fips: checksum matches\n");
+ } else {
+ check = CHECK_FAIL;
+ debug("fips: checksum mismatch!\n");
+ }
+
+cleanup:
+ free(hmac);
+ free(hmac_chk);
+ free(chk);
+ free(exe);
+
+ return check;
+}
+
+static int
+fips_check_required_proc(void)
{
int fips_required = 0;
- char *env = getenv(SSH_FORCE_FIPS_ENV);
+ int fips_fd;
+ char fips_sys = 0;
- if (env) {
- errno = 0;
- fips_required = strtol(env, NULL, 10);
- if (errno) {
- debug("bogus value in the %s environment variable, ignoring\n"
- , SSH_FORCE_FIPS_ENV);
- fips_required = 0;
- } else
- fips_required = 1;
+ struct stat dummy;
+ if (-1 == stat(FIPS_PROC_PATH, &dummy)) {
+ switch (errno) {
+ case ENOENT:
+ case ENOTDIR:
+ break;
+ default:
+ fatal("Check for system-wide FIPS mode is required and %s cannot"
+ " be accessed for reason other than non-existence - aborting"
+ , FIPS_PROC_PATH);
+ break;
+ }
+ } else {
+ if (-1 == (fips_fd = open(FIPS_PROC_PATH, O_RDONLY)))
+ fatal("Check for system-wide FIPS mode is required and %s cannot"
+ " be opened for reading - aborting"
+ , FIPS_PROC_PATH);
+ if (1 > read(fips_fd, &fips_sys, 1))
+ fatal("Check for system-wide FIPS mode is required and %s doesn't"
+ " return at least one character - aborting"
+ , FIPS_PROC_PATH);
+ close(fips_sys);
+ switch (fips_sys) {
+ case '0':
+ case '1':
+ fips_required = fips_sys - '0';
+ break;
+ default:
+ fatal("Bogus character %c found in %s - aborting"
+ , fips_sys, FIPS_PROC_PATH);
+ }
}
return fips_required;
}
+static int
+fips_check_required_env(void)
+{
+ return (NULL != getenv(SSH_FORCE_FIPS_ENV));
+}
+
+static int
+fips_required(void)
+{
+ int fips_requests = 0;
+ fips_requests += fips_check_required_proc();
+ fips_requests += fips_check_required_env();
+ return fips_requests;
+}
+
+/* check whether FIPS mode is required and perform selfchecksum/selftest */
+void
+fips_ssh_init(void)
+{
+ int checksum;
+
+ checksum = fips_hmac_self();
+
+ if (fips_required()) {
+ switch (checksum) {
+ case CHECK_OK:
+ debug("fips: mandatory checksum ok");
+ break;
+ case CHECK_FAIL:
+ fatal("fips: mandatory checksum failed - aborting");
+ break;
+ case CHECK_MISSING:
+ fatal("fips: mandatory checksum data missing - aborting");
+ break;
+ default:
+ fatal("Fatal error: internal error at %s:%u"
+ , __FILE__, __LINE__);
+ break;
+ }
+ fips_state = FIPS_mode_set(1);
+ if (1 != fips_state) {
+ ERR_load_crypto_strings();
+ u_long err = ERR_get_error();
+ error("fips: OpenSSL error %lx: %s"
+ , err, ERR_error_string(err, NULL));
+ fatal("fips: unable to set OpenSSL into FIPS mode - aborting");
+ }
+ } else {
+ switch (checksum) {
+ case CHECK_OK:
+ debug("fips: checksum ok");
+ break;
+ case CHECK_FAIL:
+ fatal("fips: checksum failed - aborting");
+ break;
+ case CHECK_MISSING:
+ debug("fips: checksum data missing, but not required - continuing non-FIPS");
+ break;
+ default:
+ fatal("Fatal error: internal error at %s:%u",
+ __FILE__, __LINE__);
+ break;
+ }
+ }
+ return;
+}
+
int
fips_mode(void)
{
Index: openssh-8.8p1/fips.h
===================================================================
--- openssh-8.8p1.orig/fips.h
+++ openssh-8.8p1/fips.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2012 Petr Cerny. All rights reserved.
+ * Copyright (c) 2012-2014 Petr Cerny. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -27,6 +27,15 @@
#include "sshkey.h"
#define SSH_FORCE_FIPS_ENV "SSH_FORCE_FIPS"
+#define FIPS_PROC_PATH "/proc/sys/crypto/fips_enabled"
+
+#define PROC_EXE_PATH_LEN 64
+#define CHECKSUM_SUFFIX ".hmac"
+#define FIPS_HMAC_KEY "HMAC_KEY:OpenSSH-FIPS@SLE"
+#define FIPS_HMAC_EVP EVP_sha256
+#define FIPS_HMAC_LEN 32
+
+void fips_ssh_init(void);
typedef enum {
FIPS_FILTER_CIPHERS,
@@ -34,6 +43,12 @@ typedef enum {
FIPS_FILTER_KEX_ALGS
} fips_filters;
+typedef enum {
+ CHECK_OK = 0,
+ CHECK_FAIL,
+ CHECK_MISSING
+} fips_checksum_status;
+
int fips_mode(void);
int fips_correct_dgst(int);
int fips_dgst_min(void);
@@ -41,4 +56,3 @@ enum fp_type fips_correct_fp_type(enum
int fips_filter_crypto(char **, fips_filters);
#endif
-
Index: openssh-8.8p1/sftp-server.c
===================================================================
--- openssh-8.8p1.orig/sftp-server.c
+++ openssh-8.8p1/sftp-server.c
@@ -57,6 +57,8 @@ char *sftp_realpath(const char *, char *
/* Maximum data read that we are willing to accept */
#define SFTP_MAX_READ_LENGTH (SFTP_MAX_MSG_LENGTH - 1024)
+#include "fips.h"
+
/* Our verbosity */
static LogLevel log_level = SYSLOG_LEVEL_ERROR;
@@ -1717,6 +1719,9 @@ sftp_server_main(int argc, char **argv,
extern char *optarg;
extern char *__progname;
+ /* initialize fips */
+ fips_ssh_init();
+
__progname = ssh_get_progname(argv[0]);
log_init(__progname, log_level, log_facility, log_stderr);
Index: openssh-8.8p1/ssh.c
===================================================================
--- openssh-8.8p1.orig/ssh.c
+++ openssh-8.8p1/ssh.c
@@ -113,6 +113,8 @@
#include "ssh-pkcs11.h"
#endif
+#include "fips.h"
+
extern char *__progname;
/* Saves a copy of argv for setproctitle emulation */
@@ -632,6 +634,10 @@ main(int ac, char **av)
u_int j;
struct ssh_conn_info *cinfo = NULL;
+ /* initialize fips - can go before ssh_malloc_init(), since that is a
+ * OpenBSD-only thing (as of OpenSSH 7.6p1) */
+ fips_ssh_init();
+
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
Index: openssh-8.8p1/sshd.c
===================================================================
--- openssh-8.8p1.orig/sshd.c
+++ openssh-8.8p1/sshd.c
@@ -1547,6 +1547,10 @@ main(int ac, char **av)
struct connection_info connection_info;
sigset_t sigmask;
+ /* initialize fips - can go before ssh_malloc_init(), since that is a
+ * OpenBSD-only thing (as of OpenSSH 7.6p1) */
+ fips_ssh_init();
+
memset(&connection_info, 0, sizeof(connection_info));
#ifdef HAVE_SECUREWARE
(void)set_auth_parameters(ac, av);
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