openssh/openssh-6.0p1-audit5.patch

diff -up openssh-6.0p1/audit-bsm.c.audit5 openssh-6.0p1/audit-bsm.c
--- openssh-6.0p1/audit-bsm.c.audit5	2012-08-06 20:37:50.036345216 +0200
+++ openssh-6.0p1/audit-bsm.c	2012-08-06 20:37:50.046345177 +0200
@@ -491,4 +491,22 @@ audit_session_key_free_body(int ctos, pi
 {
 	/* 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 -up openssh-6.0p1/audit.c.audit5 openssh-6.0p1/audit.c
--- openssh-6.0p1/audit.c.audit5	2012-08-06 20:37:50.036345216 +0200
+++ openssh-6.0p1/audit.c	2012-08-06 20:37:50.047345173 +0200
@@ -290,5 +290,24 @@ audit_session_key_free_body(int ctos, pi
 	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 -up openssh-6.0p1/audit.h.audit5 openssh-6.0p1/audit.h
--- openssh-6.0p1/audit.h.audit5	2012-08-06 20:37:50.037345212 +0200
+++ openssh-6.0p1/audit.h	2012-08-06 20:37:50.047345173 +0200
@@ -48,6 +48,8 @@ enum ssh_audit_event_type {
 };
 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);
@@ -64,5 +66,7 @@ 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 -up openssh-6.0p1/audit-linux.c.audit5 openssh-6.0p1/audit-linux.c
--- openssh-6.0p1/audit-linux.c.audit5	2012-08-06 20:37:50.037345212 +0200
+++ openssh-6.0p1/audit-linux.c	2012-08-06 20:37:50.046345177 +0200
@@ -356,4 +356,50 @@ audit_session_key_free_body(int ctos, pi
 		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 -up openssh-6.0p1/key.c.audit5 openssh-6.0p1/key.c
--- openssh-6.0p1/key.c.audit5	2012-08-06 20:37:49.992345388 +0200
+++ openssh-6.0p1/key.c	2012-08-06 20:37:50.048345169 +0200
@@ -1794,6 +1794,30 @@ key_demote(const Key *k)
 }
 
 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
+	default:
+		fatal("key_is_private: bad key type %d", k->type);
+		return 1;
+	}
+}
+
+int
 key_is_cert(const Key *k)
 {
 	if (k == NULL)
diff -up openssh-6.0p1/key.h.audit5 openssh-6.0p1/key.h
--- openssh-6.0p1/key.h.audit5	2012-08-06 20:37:49.993345384 +0200
+++ openssh-6.0p1/key.h	2012-08-06 20:37:50.049345165 +0200
@@ -109,6 +109,7 @@ 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_plain(int);
 int	 key_to_certified(Key *, int);
 int	 key_drop_cert(Key *);
diff -up openssh-6.0p1/monitor.c.audit5 openssh-6.0p1/monitor.c
--- openssh-6.0p1/monitor.c.audit5	2012-08-06 20:37:50.040345200 +0200
+++ openssh-6.0p1/monitor.c	2012-08-06 20:37:50.049345165 +0200
@@ -114,6 +114,8 @@ extern Buffer auth_debug;
 extern int auth_debug_init;
 extern Buffer loginmsg;
 
+extern void destroy_sensitive_data(int);
+
 /* State exported from the child */
 
 struct {
@@ -190,6 +192,7 @@ int mm_answer_audit_end_command(int, Buf
 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 *);
@@ -244,6 +247,7 @@ struct mon_table mon_dispatch_proto20[]
     {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},
@@ -284,6 +288,7 @@ struct mon_table mon_dispatch_postauth20
     {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}
 };
@@ -318,6 +323,7 @@ struct mon_table mon_dispatch_proto15[]
     {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}
 };
@@ -333,6 +339,7 @@ struct mon_table mon_dispatch_postauth15
     {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}
 };
@@ -1744,6 +1751,8 @@ mm_answer_term(int sock, Buffer *req)
 		sshpam_cleanup();
 #endif
 
+	destroy_sensitive_data(0);
+
 	while (waitpid(pmonitor->m_pid, &status, 0) == -1)
 		if (errno != EINTR)
 			exit(1);
@@ -2485,4 +2494,25 @@ mm_answer_audit_session_key_free_body(in
 	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);
+
+	xfree(fp);
+	buffer_clear(m);
+
+	mm_request_send(sock, MONITOR_ANS_AUDIT_SERVER_KEY_FREE, m);
+	return 0;
+}
 #endif /* SSH_AUDIT_EVENTS */
diff -up openssh-6.0p1/monitor.h.audit5 openssh-6.0p1/monitor.h
--- openssh-6.0p1/monitor.h.audit5	2012-08-06 20:37:50.040345200 +0200
+++ openssh-6.0p1/monitor.h	2012-08-06 20:37:50.050345161 +0200
@@ -64,6 +64,7 @@ enum monitor_reqtype {
 	MONITOR_REQ_AUDIT_UNSUPPORTED, MONITOR_ANS_AUDIT_UNSUPPORTED,
 	MONITOR_REQ_AUDIT_KEX, MONITOR_ANS_AUDIT_KEX,
 	MONITOR_REQ_AUDIT_SESSION_KEY_FREE, MONITOR_ANS_AUDIT_SESSION_KEY_FREE,
+	MONITOR_REQ_AUDIT_SERVER_KEY_FREE, MONITOR_ANS_AUDIT_SERVER_KEY_FREE,
 	MONITOR_REQ_TERM,
 	MONITOR_REQ_JPAKE_STEP1, MONITOR_ANS_JPAKE_STEP1,
 	MONITOR_REQ_JPAKE_GET_PWDATA, MONITOR_ANS_JPAKE_GET_PWDATA,
diff -up openssh-6.0p1/monitor_wrap.c.audit5 openssh-6.0p1/monitor_wrap.c
--- openssh-6.0p1/monitor_wrap.c.audit5	2012-08-06 20:37:50.041345196 +0200
+++ openssh-6.0p1/monitor_wrap.c	2012-08-06 20:37:50.050345161 +0200
@@ -1539,4 +1539,20 @@ mm_audit_session_key_free_body(int ctos,
 				  &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 -up openssh-6.0p1/monitor_wrap.h.audit5 openssh-6.0p1/monitor_wrap.h
--- openssh-6.0p1/monitor_wrap.h.audit5	2012-08-06 20:37:50.041345196 +0200
+++ openssh-6.0p1/monitor_wrap.h	2012-08-06 20:37:50.051345157 +0200
@@ -80,6 +80,7 @@ void mm_audit_end_command(int, const cha
 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;
diff -up openssh-6.0p1/session.c.audit5 openssh-6.0p1/session.c
--- openssh-6.0p1/session.c.audit5	2012-08-06 20:37:50.043345189 +0200
+++ openssh-6.0p1/session.c	2012-08-06 20:37:50.052345153 +0200
@@ -136,7 +136,7 @@ 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. */
@@ -1633,7 +1633,7 @@ do_child(Session *s, const char *command
 	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);
diff -up openssh-6.0p1/sshd.c.audit5 openssh-6.0p1/sshd.c
--- openssh-6.0p1/sshd.c.audit5	2012-08-06 20:37:50.044345185 +0200
+++ openssh-6.0p1/sshd.c	2012-08-06 20:37:50.053345149 +0200
@@ -255,7 +255,7 @@ Buffer loginmsg;
 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);
@@ -274,6 +274,15 @@ close_listen_socks(void)
 	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)
 {
@@ -534,22 +543,47 @@ sshd_exchange_identification(int sock_in
 	}
 }
 
-/* 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],
+					FIPS_mode() ? SSH_FP_SHA1 : SSH_FP_MD5,
+					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);
+				xfree(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;
 		}
@@ -563,6 +597,8 @@ void
 demote_sensitive_data(void)
 {
 	Key *tmp;
+	pid_t pid;
+	uid_t uid;
 	int i;
 
 	if (sensitive_data.server_key) {
@@ -571,13 +607,27 @@ demote_sensitive_data(void)
 		sensitive_data.server_key = tmp;
 	}
 
+	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],
+					FIPS_mode() ? SSH_FP_SHA1 : SSH_FP_MD5,
+					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);
+				xfree(fp);
+			}
 		}
 		/* Certs do not need demotion */
 	}
@@ -1149,6 +1199,7 @@ server_accept_loop(int *sock_in, int *so
 		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);
@@ -2054,7 +2105,7 @@ main(int ac, char **av)
 		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,
@@ -2065,6 +2116,7 @@ main(int ac, char **av)
 
 	/* 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);
@@ -2293,7 +2345,7 @@ do_ssh1_kex(void)
 			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);
@@ -2404,6 +2456,8 @@ cleanup_exit(int i)
 		}
 	}
 	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' */