openssh/openssh-6.6p1-audit6-server_key_destruction.patch

# server key destruction and auditing
# based on:
#   https://bugzilla.mindrot.org/show_bug.cgi?id=1402
#   https://bugzilla.mindrot.org/attachment.cgi?id=2015
#   by jchadima@redhat.com

diff --git a/openssh-6.6p1/audit-bsm.c b/openssh-6.6p1/audit-bsm.c
--- a/openssh-6.6p1/audit-bsm.c
+++ b/openssh-6.6p1/audit-bsm.c
@@ -486,9 +486,27 @@ audit_kex_body(int ctos, char *enc, char
 	/* not implemented */
 }
 
 void
 audit_session_key_free_body(int ctos, pid_t pid, uid_t uid)
 {
 	/* not implemented */
 }
+
+void
+audit_destroy_sensitive_data(const char *fp)
+{
+	/* not implemented */
+}
+
+void
+audit_destroy_sensitive_data(const char *fp, pid_t pid, uid_t uid)
+{
+	/* not implemented */
+}
+
+void
+audit_generate_ephemeral_server_key(const char *fp)
+{
+	/* not implemented */
+}
 #endif /* BSM */
diff --git a/openssh-6.6p1/audit-linux.c b/openssh-6.6p1/audit-linux.c
--- a/openssh-6.6p1/audit-linux.c
+++ b/openssh-6.6p1/audit-linux.c
@@ -351,9 +351,55 @@ audit_session_key_free_body(int ctos, pi
 	audit_ok = audit_log_user_message(audit_fd, AUDIT_CRYPTO_KEY_USER,
 			buf, NULL, get_remote_ipaddr(), NULL, 1);
 	audit_close(audit_fd);
 	/* do not abort if the error is EPERM and sshd is run as non root user */
 	if ((audit_ok < 0) && ((audit_ok != -1) || (getuid() == 0)))
 		error("cannot write into audit");
 }
 
+void
+audit_destroy_sensitive_data(const char *fp, pid_t pid, uid_t uid)
+{
+	char buf[AUDIT_LOG_SIZE];
+	int audit_fd, audit_ok;
+
+	snprintf(buf, sizeof(buf), "op=destroy kind=server fp=%s direction=? spid=%jd suid=%jd ",
+		fp, (intmax_t)pid, (intmax_t)uid);
+	audit_fd = audit_open();
+	if (audit_fd < 0) {
+		if (errno != EINVAL && errno != EPROTONOSUPPORT &&
+					 errno != EAFNOSUPPORT)
+			error("cannot open audit");
+		return;
+	}
+	audit_ok = audit_log_user_message(audit_fd, AUDIT_CRYPTO_KEY_USER,
+			buf, NULL,
+			listening_for_clients() ? NULL : get_remote_ipaddr(),
+			NULL, 1);
+	audit_close(audit_fd);
+	/* do not abort if the error is EPERM and sshd is run as non root user */
+	if ((audit_ok < 0) && ((audit_ok != -1) || (getuid() == 0)))
+		error("cannot write into audit");
+}
+
+void
+audit_generate_ephemeral_server_key(const char *fp)
+{
+	char buf[AUDIT_LOG_SIZE];
+	int audit_fd, audit_ok;
+
+	snprintf(buf, sizeof(buf), "op=create kind=server fp=%s direction=? ", fp);
+	audit_fd = audit_open();
+	if (audit_fd < 0) {
+		if (errno != EINVAL && errno != EPROTONOSUPPORT &&
+					 errno != EAFNOSUPPORT)
+			error("cannot open audit");
+		return;
+	}
+	audit_ok = audit_log_user_message(audit_fd, AUDIT_CRYPTO_KEY_USER,
+			buf, NULL, 0, NULL, 1);
+	audit_close(audit_fd);
+	/* do not abort if the error is EPERM and sshd is run as non root user */
+	if ((audit_ok < 0) && ((audit_ok != -1) || (getuid() == 0)))
+		error("cannot write into audit");
+}
 #endif /* USE_LINUX_AUDIT */
diff --git a/openssh-6.6p1/audit.c b/openssh-6.6p1/audit.c
--- a/openssh-6.6p1/audit.c
+++ b/openssh-6.6p1/audit.c
@@ -285,10 +285,29 @@ audit_kex_body(int ctos, char *enc, char
  * This will be called on succesfull session key discard
  */
 void
 audit_session_key_free_body(int ctos, pid_t pid, uid_t uid)
 {
 	debug("audit session key discard euid %u direction %d from pid %ld uid %u",
 		(unsigned)geteuid(), ctos, (long)pid, (unsigned)uid);
 }
+
+/*
+ * This will be called on destroy private part of the server key
+ */
+void
+audit_destroy_sensitive_data(const char *fp, pid_t pid, uid_t uid)
+{
+	debug("audit destroy sensitive data euid %d fingerprint %s from pid %ld uid %u",
+		geteuid(), fp, (long)pid, (unsigned)uid);
+}
+
+/*
+ * This will be called on generation of the ephemeral server key
+ */
+void
+audit_generate_ephemeral_server_key(const char *)
+{
+	debug("audit create ephemeral server key euid %d fingerprint %s", geteuid(), fp);
+}
 # endif  /* !defined CUSTOM_SSH_AUDIT_EVENTS */
 #endif /* SSH_AUDIT_EVENTS */
diff --git a/openssh-6.6p1/audit.h b/openssh-6.6p1/audit.h
--- a/openssh-6.6p1/audit.h
+++ b/openssh-6.6p1/audit.h
@@ -43,26 +43,30 @@ enum ssh_audit_event_type {
 	SSH_INVALID_USER,
 	SSH_NOLOGIN,		/* denied by /etc/nologin, not implemented */
 	SSH_CONNECTION_CLOSE,	/* closed after attempting auth or session */
 	SSH_CONNECTION_ABANDON,	/* closed without completing auth */
 	SSH_AUDIT_UNKNOWN
 };
 typedef enum ssh_audit_event_type ssh_audit_event_t;
 
+int	listening_for_clients(void);
+
 void	audit_connection_from(const char *, int);
 void	audit_event(ssh_audit_event_t);
 void	audit_count_session_open(void);
 void	audit_session_open(struct logininfo *);
 void	audit_session_close(struct logininfo *);
 int	audit_run_command(const char *);
 void 	audit_end_command(int, const char *);
 ssh_audit_event_t audit_classify_auth(const char *);
 int	audit_keyusage(int, const char *, unsigned, char *, int);
 void	audit_key(int, int *, const Key *);
 void	audit_unsupported(int);
 void	audit_kex(int, char *, char *, char *);
 void	audit_unsupported_body(int);
 void	audit_kex_body(int, char *, char *, char *, pid_t, uid_t);
 void	audit_session_key_free(int ctos);
 void	audit_session_key_free_body(int ctos, pid_t, uid_t);
+void	audit_destroy_sensitive_data(const char *, pid_t, uid_t);
+void	audit_generate_ephemeral_server_key(const char *);
 
 #endif /* _SSH_AUDIT_H */
diff --git a/openssh-6.6p1/key.c b/openssh-6.6p1/key.c
--- a/openssh-6.6p1/key.c
+++ b/openssh-6.6p1/key.c
@@ -1964,16 +1964,43 @@ key_demote(const Key *k)
 		fatal("key_demote: bad key type %d", k->type);
 		break;
 	}
 
 	return (pk);
 }
 
 int
+key_is_private(const Key *k)
+{
+	switch (k->type) {
+	case KEY_RSA_CERT_V00:
+	case KEY_RSA_CERT:
+	case KEY_RSA1:
+	case KEY_RSA:
+		return k->rsa->d != NULL;
+	case KEY_DSA_CERT_V00:
+	case KEY_DSA_CERT:
+	case KEY_DSA:
+		return k->dsa->priv_key != NULL;
+#ifdef OPENSSL_HAS_ECC
+	case KEY_ECDSA_CERT:
+	case KEY_ECDSA:
+		return EC_KEY_get0_private_key(k->ecdsa) != NULL;
+#endif
+	case KEY_ED25519_CERT:
+	case KEY_ED25519:
+		return k->ed25519_sk != NULL;
+	default:
+		fatal("key_is_private: bad key type %d", k->type);
+		return 1;
+	}
+}
+
+int
 key_is_cert(const Key *k)
 {
 	if (k == NULL)
 		return 0;
 	return key_type_is_cert(k->type);
 }
 
 /* Return the cert-less equivalent to a certified key type */
diff --git a/openssh-6.6p1/key.h b/openssh-6.6p1/key.h
--- a/openssh-6.6p1/key.h
+++ b/openssh-6.6p1/key.h
@@ -113,16 +113,17 @@ int		 key_read(Key *, char **);
 u_int		 key_size(const Key *);
 enum fp_type	 key_fp_type_select(void);
 char		*key_fp_type_str(enum fp_type);
 
 Key	*key_generate(int, u_int);
 Key	*key_from_private(const Key *);
 int	 key_type_from_name(char *);
 int	 key_is_cert(const Key *);
+int	 key_is_private(const Key *k);
 int	 key_type_is_cert(int);
 int	 key_type_plain(int);
 int	 key_to_certified(Key *, int);
 int	 key_drop_cert(Key *);
 int	 key_certify(Key *, Key *);
 void	 key_cert_copy(const Key *, struct Key *);
 int	 key_cert_check_authority(const Key *, int, int, const char *,
 	    const char **);
diff --git a/openssh-6.6p1/monitor.c b/openssh-6.6p1/monitor.c
--- a/openssh-6.6p1/monitor.c
+++ b/openssh-6.6p1/monitor.c
@@ -109,16 +109,18 @@ extern u_int utmp_len;
 extern Newkeys *current_keys[];
 extern z_stream incoming_stream;
 extern z_stream outgoing_stream;
 extern u_char session_id[];
 extern Buffer auth_debug;
 extern int auth_debug_init;
 extern Buffer loginmsg;
 
+extern void destroy_sensitive_data(int);
+
 /* State exported from the child */
 
 struct {
 	z_stream incoming;
 	z_stream outgoing;
 	u_char *keyin;
 	u_int keyinlen;
 	u_char *keyout;
@@ -180,16 +182,17 @@ int mm_answer_gss_checkmic(int, Buffer *
 
 #ifdef SSH_AUDIT_EVENTS
 int mm_answer_audit_event(int, Buffer *);
 int mm_answer_audit_command(int, Buffer *);
 int mm_answer_audit_end_command(int, Buffer *);
 int mm_answer_audit_unsupported_body(int, Buffer *);
 int mm_answer_audit_kex_body(int, Buffer *);
 int mm_answer_audit_session_key_free_body(int, Buffer *);
+int mm_answer_audit_server_key_free(int, Buffer *);
 #endif
 
 static int monitor_read_log(struct monitor *);
 
 static Authctxt *authctxt;
 static BIGNUM *ssh1_challenge = NULL;	/* used for ssh1 rsa auth */
 
 /* local state for key verify */
@@ -234,16 +237,17 @@ struct mon_table mon_dispatch_proto20[] 
     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 #endif
 #ifdef SSH_AUDIT_EVENTS
     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
     {MONITOR_REQ_AUDIT_UNSUPPORTED, MON_PERMIT, mm_answer_audit_unsupported_body},
     {MONITOR_REQ_AUDIT_KEX, MON_PERMIT, mm_answer_audit_kex_body},
     {MONITOR_REQ_AUDIT_SESSION_KEY_FREE, MON_PERMIT, mm_answer_audit_session_key_free_body},
+    {MONITOR_REQ_AUDIT_SERVER_KEY_FREE, MON_PERMIT, mm_answer_audit_server_key_free},
 #endif
 #ifdef BSD_AUTH
     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 #endif
 #ifdef SKEY
     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
@@ -267,16 +271,17 @@ struct mon_table mon_dispatch_postauth20
     {MONITOR_REQ_TERM, 0, mm_answer_term},
 #ifdef SSH_AUDIT_EVENTS
     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
     {MONITOR_REQ_AUDIT_END_COMMAND, MON_PERMIT, mm_answer_audit_end_command},
     {MONITOR_REQ_AUDIT_UNSUPPORTED, MON_PERMIT, mm_answer_audit_unsupported_body},
     {MONITOR_REQ_AUDIT_KEX, MON_PERMIT, mm_answer_audit_kex_body},
     {MONITOR_REQ_AUDIT_SESSION_KEY_FREE, MON_PERMIT, mm_answer_audit_session_key_free_body},
+    {MONITOR_REQ_AUDIT_SERVER_KEY_FREE, MON_PERMIT, mm_answer_audit_server_key_free},
 #endif
     {0, 0, NULL}
 };
 
 struct mon_table mon_dispatch_proto15[] = {
     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
     {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
     {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
@@ -301,31 +306,33 @@ struct mon_table mon_dispatch_proto15[] 
     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 #endif
 #ifdef SSH_AUDIT_EVENTS
     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
     {MONITOR_REQ_AUDIT_UNSUPPORTED, MON_PERMIT, mm_answer_audit_unsupported_body},
     {MONITOR_REQ_AUDIT_KEX, MON_PERMIT, mm_answer_audit_kex_body},
     {MONITOR_REQ_AUDIT_SESSION_KEY_FREE, MON_PERMIT, mm_answer_audit_session_key_free_body},
+    {MONITOR_REQ_AUDIT_SERVER_KEY_FREE, MON_PERMIT, mm_answer_audit_server_key_free},
 #endif
     {0, 0, NULL}
 };
 
 struct mon_table mon_dispatch_postauth15[] = {
     {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
     {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
     {MONITOR_REQ_TERM, 0, mm_answer_term},
 #ifdef SSH_AUDIT_EVENTS
     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
     {MONITOR_REQ_AUDIT_END_COMMAND, MON_PERMIT, mm_answer_audit_end_command},
     {MONITOR_REQ_AUDIT_UNSUPPORTED, MON_PERMIT, mm_answer_audit_unsupported_body},
     {MONITOR_REQ_AUDIT_KEX, MON_PERMIT, mm_answer_audit_kex_body},
     {MONITOR_REQ_AUDIT_SESSION_KEY_FREE, MON_PERMIT, mm_answer_audit_session_key_free_body},
+    {MONITOR_REQ_AUDIT_SERVER_KEY_FREE, MON_PERMIT, mm_answer_audit_server_key_free},
 #endif
     {0, 0, NULL}
 };
 
 struct mon_table *mon_dispatch;
 
 /* Specifies if a certain message is allowed at the moment */
 
@@ -1739,16 +1746,18 @@ mm_answer_term(int sock, Buffer *req)
 	/* The child is terminating */
 	session_destroy_all(&mm_session_close);
 
 #ifdef USE_PAM
 	if (options.use_pam)
 		sshpam_cleanup();
 #endif
 
+	destroy_sensitive_data(0);
+
 	while (waitpid(pmonitor->m_pid, &status, 0) == -1)
 		if (errno != EINTR)
 			exit(1);
 
 	res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
 
 	/* Terminate process */
 	exit(res);
@@ -2280,10 +2289,31 @@ mm_answer_audit_session_key_free_body(in
 
 	audit_session_key_free_body(ctos, pid, uid);
 
 	buffer_clear(m);
 
 	mm_request_send(sock, MONITOR_ANS_AUDIT_SESSION_KEY_FREE, m);
 	return 0;
 }
+
+int
+mm_answer_audit_server_key_free(int sock, Buffer *m)
+{
+	int len;
+	char *fp;
+	pid_t pid;
+	uid_t uid;
+
+	fp = buffer_get_string(m, &len);
+	pid = buffer_get_int64(m);
+	uid = buffer_get_int64(m);
+
+	audit_destroy_sensitive_data(fp, pid, uid);
+
+	free(fp);
+	buffer_clear(m);
+
+	mm_request_send(sock, MONITOR_ANS_AUDIT_SERVER_KEY_FREE, m);
+	return 0;
+}
 #endif /* SSH_AUDIT_EVENTS */
 
diff --git a/openssh-6.6p1/monitor.h b/openssh-6.6p1/monitor.h
--- a/openssh-6.6p1/monitor.h
+++ b/openssh-6.6p1/monitor.h
@@ -63,16 +63,17 @@ enum monitor_reqtype {
 	MONITOR_REQ_PAM_QUERY = 106, MONITOR_ANS_PAM_QUERY = 107,
 	MONITOR_REQ_PAM_RESPOND = 108, MONITOR_ANS_PAM_RESPOND = 109,
 	MONITOR_REQ_PAM_FREE_CTX = 110, MONITOR_ANS_PAM_FREE_CTX = 111,
 	MONITOR_REQ_AUDIT_EVENT = 112, MONITOR_REQ_AUDIT_COMMAND = 113,
 	MONITOR_ANS_AUDIT_COMMAND = 114, MONITOR_REQ_AUDIT_END_COMMAND = 115,
 	MONITOR_REQ_AUDIT_UNSUPPORTED = 116, MONITOR_ANS_AUDIT_UNSUPPORTED = 117,
 	MONITOR_REQ_AUDIT_KEX = 118, MONITOR_ANS_AUDIT_KEX = 119,
 	MONITOR_REQ_AUDIT_SESSION_KEY_FREE = 120, MONITOR_ANS_AUDIT_SESSION_KEY_FREE = 121,
+	MONITOR_REQ_AUDIT_SERVER_KEY_FREE = 122, MONITOR_ANS_AUDIT_SERVER_KEY_FREE = 123,
 
 };
 
 struct mm_master;
 struct monitor {
 	int			 m_recvfd;
 	int			 m_sendfd;
 	int			 m_log_recvfd;
diff --git a/openssh-6.6p1/monitor_wrap.c b/openssh-6.6p1/monitor_wrap.c
--- a/openssh-6.6p1/monitor_wrap.c
+++ b/openssh-6.6p1/monitor_wrap.c
@@ -1373,10 +1373,26 @@ mm_audit_session_key_free_body(int ctos,
 	buffer_put_int(&m, ctos);
 	buffer_put_int64(&m, pid);
 	buffer_put_int64(&m, uid);
 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_SESSION_KEY_FREE, &m);
 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUDIT_SESSION_KEY_FREE,
 				  &m);
 	buffer_free(&m);
 }
+
+void
+mm_audit_destroy_sensitive_data(const char *fp, pid_t pid, uid_t uid)
+{
+	Buffer m;
+
+	buffer_init(&m);
+	buffer_put_cstring(&m, fp);
+	buffer_put_int64(&m, pid);
+	buffer_put_int64(&m, uid);
+
+	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_SERVER_KEY_FREE, &m);
+	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUDIT_SERVER_KEY_FREE,
+				  &m);
+	buffer_free(&m);
+}
 #endif /* SSH_AUDIT_EVENTS */
 
diff --git a/openssh-6.6p1/monitor_wrap.h b/openssh-6.6p1/monitor_wrap.h
--- a/openssh-6.6p1/monitor_wrap.h
+++ b/openssh-6.6p1/monitor_wrap.h
@@ -75,16 +75,17 @@ void mm_sshpam_free_ctx(void *);
 #ifdef SSH_AUDIT_EVENTS
 #include "audit.h"
 void mm_audit_event(ssh_audit_event_t);
 int mm_audit_run_command(const char *);
 void mm_audit_end_command(int, const char *);
 void mm_audit_unsupported_body(int);
 void mm_audit_kex_body(int, char *, char *, char *, pid_t, uid_t);
 void mm_audit_session_key_free_body(int, pid_t, uid_t);
+void mm_audit_destroy_sensitive_data(const char *, pid_t, uid_t);
 #endif
 
 struct Session;
 void mm_terminate(void);
 int mm_pty_allocate(int *, int *, char *, size_t);
 void mm_session_pty_cleanup2(struct Session *);
 
 /* SSHv1 interfaces */
diff --git a/openssh-6.6p1/session.c b/openssh-6.6p1/session.c
--- a/openssh-6.6p1/session.c
+++ b/openssh-6.6p1/session.c
@@ -132,17 +132,17 @@ static int session_pty_req(Session *);
 
 /* import */
 extern ServerOptions options;
 extern char *__progname;
 extern int log_stderr;
 extern int debug_flag;
 extern u_int utmp_len;
 extern int startup_pipe;
-extern void destroy_sensitive_data(void);
+extern void destroy_sensitive_data(int);
 extern Buffer loginmsg;
 
 /* original command from peer. */
 const char *original_command = NULL;
 
 /* data */
 static int sessions_first_unused = -1;
 static int sessions_nalloc = 0;
@@ -1693,17 +1693,17 @@ do_child(Session *s, const char *command
 	char **env;
 	int env_size;
 	char *argv[ARGV_MAX];
 	const char *shell, *shell0, *hostname = NULL;
 	struct passwd *pw = s->pw;
 	int r = 0;
 
 	/* remove hostkey from the child's memory */
-	destroy_sensitive_data();
+	destroy_sensitive_data(1);
 	/* Don't audit this - both us and the parent would be talking to the
 	   monitor over a single socket, with no synchronization. */
 	packet_destroy_all(0, 1);
 
 	/* Force a password change */
 	if (s->authctxt->force_pwchange) {
 		do_setusercontext(pw);
 		child_close_fds();
diff --git a/openssh-6.6p1/sshd.c b/openssh-6.6p1/sshd.c
--- a/openssh-6.6p1/sshd.c
+++ b/openssh-6.6p1/sshd.c
@@ -259,17 +259,17 @@ Buffer cfg;
 
 /* message to be displayed after login */
 Buffer loginmsg;
 
 /* Unprivileged user */
 struct passwd *privsep_pw = NULL;
 
 /* Prototypes for various functions defined later in this file. */
-void destroy_sensitive_data(void);
+void destroy_sensitive_data(int);
 void demote_sensitive_data(void);
 
 static void do_ssh1_kex(void);
 static void do_ssh2_kex(void);
 
 /*
  * Close all listening sockets
  */
@@ -278,16 +278,25 @@ close_listen_socks(void)
 {
 	int i;
 
 	for (i = 0; i < num_listen_socks; i++)
 		close(listen_socks[i]);
 	num_listen_socks = -1;
 }
 
+/*
+ * Is this process listening for clients (i.e. not specific to any specific
+ * client connection?)
+ */
+int listening_for_clients(void)
+{
+	return num_listen_socks > 0;
+}
+
 static void
 close_startup_pipes(void)
 {
 	int i;
 
 	if (startup_pipes)
 		for (i = 0; i < options.max_startups; i++)
 			if (startup_pipes[i] != -1)
@@ -557,60 +566,99 @@ sshd_exchange_identification(int sock_in
 		close(sock_out);
 		logit("Protocol major versions differ for %s: %.200s vs. %.200s",
 		    get_remote_ipaddr(),
 		    server_version_string, client_version_string);
 		cleanup_exit(255);
 	}
 }
 
-/* Destroy the host and server keys.  They will no longer be needed. */
+/*
+ * Destroy the host and server keys.  They will no longer be needed.  Careful,
+ * this can be called from cleanup_exit() - i.e. from just about anywhere.
+ */
 void
-destroy_sensitive_data(void)
+destroy_sensitive_data(int privsep)
 {
 	int i;
+	pid_t pid;
+	uid_t uid;
 
 	if (sensitive_data.server_key) {
 		key_free(sensitive_data.server_key);
 		sensitive_data.server_key = NULL;
 	}
+	pid = getpid();
+	uid = getuid();
 	for (i = 0; i < options.num_host_key_files; i++) {
 		if (sensitive_data.host_keys[i]) {
+			char *fp;
+
+			if (key_is_private(sensitive_data.host_keys[i]))
+				fp = key_fingerprint(sensitive_data.host_keys[i],
+					key_fp_type_select(), SSH_FP_HEX);
+			else
+				fp = NULL;
 			key_free(sensitive_data.host_keys[i]);
 			sensitive_data.host_keys[i] = NULL;
+			if (fp != NULL) {
+				if (privsep)
+					PRIVSEP(audit_destroy_sensitive_data(fp,
+						pid, uid));
+				else
+					audit_destroy_sensitive_data(fp,
+						pid, uid);
+				free(fp);
+			}
 		}
-		if (sensitive_data.host_certificates[i]) {
+		if (sensitive_data.host_certificates
+		    && sensitive_data.host_certificates[i]) {
 			key_free(sensitive_data.host_certificates[i]);
 			sensitive_data.host_certificates[i] = NULL;
 		}
 	}
 	sensitive_data.ssh1_host_key = NULL;
 	explicit_bzero(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
 }
 
 /* Demote private to public keys for network child */
 void
 demote_sensitive_data(void)
 {
 	Key *tmp;
+	pid_t pid;
+	uid_t uid;
 	int i;
 
+	pid = getpid();
+	uid = getuid();
 	if (sensitive_data.server_key) {
 		tmp = key_demote(sensitive_data.server_key);
 		key_free(sensitive_data.server_key);
 		sensitive_data.server_key = tmp;
 	}
 
 	for (i = 0; i < options.num_host_key_files; i++) {
 		if (sensitive_data.host_keys[i]) {
+			char *fp;
+
+			if (key_is_private(sensitive_data.host_keys[i]))
+				fp = key_fingerprint(sensitive_data.host_keys[i],
+					key_fp_type_select(), SSH_FP_HEX);
+			else
+				fp = NULL;
 			tmp = key_demote(sensitive_data.host_keys[i]);
 			key_free(sensitive_data.host_keys[i]);
 			sensitive_data.host_keys[i] = tmp;
 			if (tmp->type == KEY_RSA1)
 				sensitive_data.ssh1_host_key = tmp;
+			if (fp != NULL) {
+				audit_destroy_sensitive_data(fp, pid, uid);
+				free(fp);
+			}
 		}
 		/* Certs do not need demotion */
 	}
 
 	/* We do not clear ssh1_host key and cookie.  XXX - Okay Niels? */
 }
 
 static void
@@ -1201,16 +1249,17 @@ server_accept_loop(int *sock_in, int *so
 
 		/* Wait in select until there is a connection. */
 		ret = select(maxfd+1, fdset, NULL, NULL, NULL);
 		if (ret < 0 && errno != EINTR)
 			error("select: %.100s", strerror(errno));
 		if (received_sigterm) {
 			logit("Received signal %d; terminating.",
 			    (int) received_sigterm);
+			destroy_sensitive_data(0);
 			close_listen_socks();
 			unlink(options.pid_file);
 			exit(received_sigterm == SIGTERM ? 0 : 255);
 		}
 		if (key_used && key_do_regen) {
 			generate_ephemeral_server_key();
 			key_used = 0;
 			key_do_regen = 0;
@@ -2167,27 +2216,28 @@ main(int ac, char **av)
 	/*
 	 * In privilege separation, we fork another child and prepare
 	 * file descriptor passing.
 	 */
 	if (use_privsep) {
 		privsep_postauth(authctxt);
 		/* the monitor process [priv] will not return */
 		if (!compat20)
-			destroy_sensitive_data();
+			destroy_sensitive_data(0);
 	}
 
 	packet_set_timeout(options.client_alive_interval,
 	    options.client_alive_count_max);
 
 	/* Start session. */
 	do_authenticated(authctxt);
 
 	/* The connection has been terminated. */
 	packet_destroy_all(1, 1);
+	destroy_sensitive_data(1);
 
 	packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes);
 	packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes);
 	verbose("Transferred: sent %llu, received %llu bytes",
 	    (unsigned long long)obytes, (unsigned long long)ibytes);
 
 	verbose("Closing connection to %.500s port %d", remote_ip, remote_port);
 
@@ -2412,17 +2462,17 @@ do_ssh1_kex(void)
 			fatal("%s: hash failed", __func__);
 		ssh_digest_free(md);
 		explicit_bzero(buf, bytes);
 		free(buf);
 		for (i = 0; i < 16; i++)
 			session_id[i] = session_key[i] ^ session_key[i + 16];
 	}
 	/* Destroy the private and public keys. No longer. */
-	destroy_sensitive_data();
+	destroy_sensitive_data(0);
 
 	if (use_privsep)
 		mm_ssh1_session_id(session_id);
 
 	/* Destroy the decrypted integer.  It is no longer needed. */
 	BN_clear_free(session_key_int);
 
 	/* Set the session key.  From this on all communications will be encrypted. */
@@ -2556,16 +2606,18 @@ cleanup_exit(int i)
 			debug("Killing privsep child %d", pmonitor->m_pid);
 			if (kill(pmonitor->m_pid, SIGKILL) != 0 &&
 			    errno != ESRCH)
 				error("%s: kill(%d): %s", __func__,
 				    pmonitor->m_pid, strerror(errno));
 		}
 	}
 	is_privsep_child = use_privsep && (pmonitor != NULL) && !mm_is_monitor();
+	if (sensitive_data.host_keys != NULL)
+		destroy_sensitive_data(is_privsep_child);
 	packet_destroy_all(1, is_privsep_child);
 #ifdef SSH_AUDIT_EVENTS
 	/* done after do_cleanup so it can cancel the PAM auth 'thread' */
 	if ((the_authctxt == NULL || !the_authctxt->authenticated) &&
 	    (!use_privsep || mm_is_monitor()))
 		audit_event(SSH_CONNECTION_ABANDON);
 #endif
 	_exit(i);