openssh/openssh-6.5p1-audit5-session_key_destruction.patch

# session key destruction and auditing
# based on:
#   https://bugzilla.mindrot.org/show_bug.cgi?id=1402
#   https://bugzilla.mindrot.org/attachment.cgi?id=2014
#   by jchadima@redhat.com

diff --git a/openssh-6.5p1/audit-bsm.c b/openssh-6.5p1/audit-bsm.c
--- a/openssh-6.5p1/audit-bsm.c
+++ b/openssh-6.5p1/audit-bsm.c
@@ -480,9 +480,15 @@ audit_unsupported_body(int what)
 	/* not implemented */
 }
 
 void
 audit_kex_body(int ctos, char *enc, char *mac, char *compress, pid_t pid, uid_t uid)
 {
 	/* not implemented */
 }
+
+void
+audit_session_key_free_body(int ctos, pid_t pid, uid_t uid)
+{
+	/* not implemented */
+}
 #endif /* BSM */
diff --git a/openssh-6.5p1/audit-linux.c b/openssh-6.5p1/audit-linux.c
--- a/openssh-6.5p1/audit-linux.c
+++ b/openssh-6.5p1/audit-linux.c
@@ -289,24 +289,25 @@ audit_unsupported_body(int what)
 		/* no problem, the next instruction will be fatal() */
 		return;
 	audit_log_user_message(audit_fd, AUDIT_CRYPTO_SESSION,
 			buf, NULL, get_remote_ipaddr(), NULL, 0);
 	audit_close(audit_fd);
 #endif
 }
 
+const static char *direction[] = { "from-server", "from-client", "both" };
+
 void
 audit_kex_body(int ctos, char *enc, char *mac, char *compress, pid_t pid,
 	       uid_t uid)
 {
 #ifdef AUDIT_CRYPTO_SESSION
 	char buf[AUDIT_LOG_SIZE];
 	int audit_fd, audit_ok;
-	const static char *direction[] = { "from-server", "from-client", "both" };
 	Cipher *cipher = cipher_by_name(enc);
 	char *s;
 
 	snprintf(buf, sizeof(buf), "op=start direction=%s cipher=%s ksize=%d spid=%jd suid=%jd rport=%d laddr=%s lport=%d ",
 		direction[ctos], enc, cipher ? 8 * cipher->key_len : 0,
 		(intmax_t)pid, (intmax_t)uid,
 		get_remote_port(), (s = get_local_ipaddr(packet_get_connection_in())), get_local_port());
 	free(s);
@@ -322,9 +323,37 @@ audit_kex_body(int ctos, char *enc, char
 			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)))
 		fatal("cannot write into audit"); /* Must prevent login */
 #endif
 }
 
+void
+audit_session_key_free_body(int ctos, pid_t pid, uid_t uid)
+{
+	char buf[AUDIT_LOG_SIZE];
+	int audit_fd, audit_ok;
+	char *s;
+
+	snprintf(buf, sizeof(buf), "op=destroy kind=session fp=? direction=%s spid=%jd suid=%jd rport=%d laddr=%s lport=%d ",
+		 direction[ctos], (intmax_t)pid, (intmax_t)uid,
+		 get_remote_port(),
+		 (s = get_local_ipaddr(packet_get_connection_in())),
+		 get_local_port());
+	free(s);
+	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, 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");
+}
+
 #endif /* USE_LINUX_AUDIT */
diff --git a/openssh-6.5p1/audit.c b/openssh-6.5p1/audit.c
--- a/openssh-6.5p1/audit.c
+++ b/openssh-6.5p1/audit.c
@@ -138,16 +138,22 @@ audit_unsupported(int what)
 }
 
 void
 audit_kex(int ctos, char *enc, char *mac, char *comp)
 {
 	PRIVSEP(audit_kex_body(ctos, enc, mac, comp, getpid(), getuid()));
 }
 
+void
+audit_session_key_free(int ctos)
+{
+	PRIVSEP(audit_session_key_free_body(ctos, getpid(), getuid()));
+}
+
 # ifndef CUSTOM_SSH_AUDIT_EVENTS
 /*
  * Null implementations of audit functions.
  * These get used if SSH_AUDIT_EVENTS is defined but no audit module is enabled.
  */
 
 /*
  * Called after a connection has been accepted but before any authentication
@@ -269,10 +275,20 @@ audit_unsupported_body(int what)
 void
 audit_kex_body(int ctos, char *enc, char *mac, char *compress, pid_t pid,
 	       uid_t uid)
 {
 	debug("audit protocol negotiation euid %d direction %d cipher %s mac %s compresion %s from pid %ld uid %u",
 		(unsigned)geteuid(), ctos, enc, mac, compress, (long)pid,
 	        (unsigned)uid);
 }
+
+/*
+ * 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);
+}
 # endif  /* !defined CUSTOM_SSH_AUDIT_EVENTS */
 #endif /* SSH_AUDIT_EVENTS */
diff --git a/openssh-6.5p1/audit.h b/openssh-6.5p1/audit.h
--- a/openssh-6.5p1/audit.h
+++ b/openssh-6.5p1/audit.h
@@ -57,10 +57,12 @@ 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);
 
 #endif /* _SSH_AUDIT_H */
diff --git a/openssh-6.5p1/auditstub.c b/openssh-6.5p1/auditstub.c
--- a/openssh-6.5p1/auditstub.c
+++ b/openssh-6.5p1/auditstub.c
@@ -22,18 +22,29 @@
  * 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.
  *
  * Red Hat author: Jan F. Chadima <jchadima@redhat.com>
  */
 
+#include <sys/types.h>
+
 void
 audit_unsupported(int n)
 {
 }
 
 void
 audit_kex(int ctos, char *enc, char *mac, char *comp)
 {
 }
 
+void
+audit_session_key_free(int ctos)
+{
+}
+
+void
+audit_session_key_free_body(int ctos, pid_t pid, uid_t uid)
+{
+}
diff --git a/openssh-6.5p1/kex.c b/openssh-6.5p1/kex.c
--- a/openssh-6.5p1/kex.c
+++ b/openssh-6.5p1/kex.c
@@ -698,8 +698,39 @@ dump_digest(char *msg, u_char *digest, i
 		if (i%32 == 31)
 			fprintf(stderr, "\n");
 		else if (i%8 == 7)
 			fprintf(stderr, " ");
 	}
 	fprintf(stderr, "\n");
 }
 #endif
+
+static void
+enc_destroy(Enc *enc)
+{
+	if (enc == NULL)
+		return;
+
+	if (enc->key) {
+		memset(enc->key, 0, enc->key_len);
+		free(enc->key);
+	}
+
+	if (enc->iv) {
+		memset(enc->iv,  0, enc->block_size);
+		free(enc->iv);
+	}
+
+	memset(enc, 0, sizeof(*enc));
+}
+
+void
+newkeys_destroy(Newkeys *newkeys)
+{
+	if (newkeys == NULL)
+		return;
+
+	enc_destroy(&newkeys->enc);
+	mac_destroy(&newkeys->mac);
+	memset(&newkeys->comp, 0, sizeof(newkeys->comp));
+}
+
diff --git a/openssh-6.5p1/kex.h b/openssh-6.5p1/kex.h
--- a/openssh-6.5p1/kex.h
+++ b/openssh-6.5p1/kex.h
@@ -163,16 +163,18 @@ void	 kexdh_client(Kex *);
 void	 kexdh_server(Kex *);
 void	 kexgex_client(Kex *);
 void	 kexgex_server(Kex *);
 void	 kexecdh_client(Kex *);
 void	 kexecdh_server(Kex *);
 void	 kexc25519_client(Kex *);
 void	 kexc25519_server(Kex *);
 
+void	 newkeys_destroy(Newkeys *newkeys);
+
 void
 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
     BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
 void
 kexgex_hash(int, char *, char *, char *, int, char *,
     int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
     BIGNUM *, BIGNUM *, u_char **, u_int *);
 #ifdef OPENSSL_HAS_ECC
diff --git a/openssh-6.5p1/mac.c b/openssh-6.5p1/mac.c
--- a/openssh-6.5p1/mac.c
+++ b/openssh-6.5p1/mac.c
@@ -219,16 +219,30 @@ mac_clear(Mac *mac)
 		if (mac->umac_ctx != NULL)
 			umac128_delete(mac->umac_ctx);
 	} else if (mac->evp_md != NULL)
 		HMAC_cleanup(&mac->evp_ctx);
 	mac->evp_md = NULL;
 	mac->umac_ctx = NULL;
 }
 
+void
+mac_destroy(Mac *mac)
+{
+	if (mac == NULL)
+		return;
+
+	if (mac->key) {
+		memset(mac->key, 0, mac->key_len);
+		free(mac->key);
+	}
+
+	memset(mac, 0, sizeof(*mac));
+}
+
 /* XXX copied from ciphers_valid */
 #define	MAC_SEP	","
 int
 mac_valid(const char *names)
 {
 	char *maclist, *cp, *p;
 
 	if (names == NULL || strcmp(names, "") == 0)
diff --git a/openssh-6.5p1/mac.h b/openssh-6.5p1/mac.h
--- a/openssh-6.5p1/mac.h
+++ b/openssh-6.5p1/mac.h
@@ -24,8 +24,9 @@
  */
 
 int	 mac_valid(const char *);
 char	*mac_alg_list(char);
 int	 mac_setup(Mac *, char *);
 int	 mac_init(Mac *);
 u_char	*mac_compute(Mac *, u_int32_t, u_char *, int);
 void	 mac_clear(Mac *);
+void	 mac_destroy(Mac *);
diff --git a/openssh-6.5p1/monitor.c b/openssh-6.5p1/monitor.c
--- a/openssh-6.5p1/monitor.c
+++ b/openssh-6.5p1/monitor.c
@@ -185,16 +185,17 @@ int mm_answer_gss_checkmic(int, Buffer *
 #endif
 
 #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 *);
 #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 */
@@ -238,16 +239,17 @@ struct mon_table mon_dispatch_proto20[] 
     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
     {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},
 #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},
@@ -277,16 +279,17 @@ struct mon_table mon_dispatch_postauth20
     {MONITOR_REQ_PTYCLEANUP, 0, 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, 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},
 #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},
@@ -310,30 +313,32 @@ struct mon_table mon_dispatch_proto15[] 
     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
     {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},
 #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},
 #endif
     {0, 0, NULL}
 };
 
 struct mon_table *mon_dispatch;
 
 /* Specifies if a certain message is allowed at the moment */
 
@@ -1971,21 +1976,23 @@ mm_get_keystate(struct monitor *pmonitor
 		goto skip;
 	} else {
 		/* Get the Kex for rekeying */
 		*pmonitor->m_pkex = mm_get_kex(&m);
 	}
 
 	blob = buffer_get_string(&m, &bloblen);
 	current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
+	memset(blob, 0, bloblen);
 	free(blob);
 
 	debug3("%s: Waiting for second key", __func__);
 	blob = buffer_get_string(&m, &bloblen);
 	current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
+	memset(blob, 0, bloblen);
 	free(blob);
 
 	/* Now get sequence numbers for the packets */
 	seqnr = buffer_get_int(&m);
 	blocks = buffer_get_int64(&m);
 	packets = buffer_get_int(&m);
 	bytes = buffer_get_int64(&m);
 	packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes);
@@ -2021,16 +2028,31 @@ mm_get_keystate(struct monitor *pmonitor
 
 	/* Roaming */
 	if (compat20) {
 		child_state.sent_bytes = buffer_get_int64(&m);
 		child_state.recv_bytes = buffer_get_int64(&m);
 	}
 
 	buffer_free(&m);
+
+#ifdef SSH_AUDIT_EVENTS
+	if (compat20) {
+		buffer_init(&m);
+		mm_request_receive_expect(pmonitor->m_sendfd,
+					  MONITOR_REQ_AUDIT_SESSION_KEY_FREE, &m);
+		mm_answer_audit_session_key_free_body(pmonitor->m_sendfd, &m);
+		buffer_free(&m);
+	}
+#endif
+
+	/* Drain any buffered messages from the child */
+	while (pmonitor->m_log_recvfd >= 0 && monitor_read_log(pmonitor) == 0)
+		;
+
 }
 
 
 /* Allocation functions for zlib */
 void *
 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
 {
 	size_t len = (size_t) size * ncount;
@@ -2465,9 +2487,27 @@ mm_answer_audit_kex_body(int sock, Buffe
 	free(mac);
 	free(compress);
 	buffer_clear(m);
 
 	mm_request_send(sock, MONITOR_ANS_AUDIT_KEX, m);
 	return 0;
 }
 
+int
+mm_answer_audit_session_key_free_body(int sock, Buffer *m)
+{
+	int ctos;
+	pid_t pid;
+	uid_t uid;
+
+	ctos = buffer_get_int(m);
+	pid = buffer_get_int64(m);
+	uid = buffer_get_int64(m);
+
+	audit_session_key_free_body(ctos, pid, uid);
+
+	buffer_clear(m);
+
+	mm_request_send(sock, MONITOR_ANS_AUDIT_SESSION_KEY_FREE, m);
+	return 0;
+}
 #endif /* SSH_AUDIT_EVENTS */
diff --git a/openssh-6.5p1/monitor.h b/openssh-6.5p1/monitor.h
--- a/openssh-6.5p1/monitor.h
+++ b/openssh-6.5p1/monitor.h
@@ -67,16 +67,17 @@ enum monitor_reqtype {
 	MONITOR_REQ_PAM_INIT_CTX = 104, MONITOR_ANS_PAM_INIT_CTX = 105,
 	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,
 
 };
 
 struct mm_master;
 struct monitor {
 	int			 m_recvfd;
 	int			 m_sendfd;
 	int			 m_log_recvfd;
diff --git a/openssh-6.5p1/monitor_wrap.c b/openssh-6.5p1/monitor_wrap.c
--- a/openssh-6.5p1/monitor_wrap.c
+++ b/openssh-6.5p1/monitor_wrap.c
@@ -651,22 +651,24 @@ mm_send_keystate(struct monitor *monitor
 	    __func__, packet_get_newkeys(MODE_OUT),
 	    packet_get_newkeys(MODE_IN));
 
 	/* Keys from Kex */
 	if (!mm_newkeys_to_blob(MODE_OUT, &blob, &bloblen))
 		fatal("%s: conversion of newkeys failed", __func__);
 
 	buffer_put_string(&m, blob, bloblen);
+	memset(blob, 0, bloblen);
 	free(blob);
 
 	if (!mm_newkeys_to_blob(MODE_IN, &blob, &bloblen))
 		fatal("%s: conversion of newkeys failed", __func__);
 
 	buffer_put_string(&m, blob, bloblen);
+	memset(blob, 0, bloblen);
 	free(blob);
 
 	packet_get_state(MODE_OUT, &seqnr, &blocks, &packets, &bytes);
 	buffer_put_int(&m, seqnr);
 	buffer_put_int64(&m, blocks);
 	buffer_put_int(&m, packets);
 	buffer_put_int64(&m, bytes);
 	packet_get_state(MODE_IN, &seqnr, &blocks, &packets, &bytes);
@@ -1520,9 +1522,24 @@ mm_audit_kex_body(int ctos, char *cipher
 	buffer_put_int64(&m, uid);
 
 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_KEX, &m);
 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUDIT_KEX,
 				  &m);
 
 	buffer_free(&m);
 }
+
+void
+mm_audit_session_key_free_body(int ctos, pid_t pid, uid_t uid)
+{
+	Buffer m;
+
+	buffer_init(&m);
+	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);
+}
 #endif /* SSH_AUDIT_EVENTS */
diff --git a/openssh-6.5p1/monitor_wrap.h b/openssh-6.5p1/monitor_wrap.h
--- a/openssh-6.5p1/monitor_wrap.h
+++ b/openssh-6.5p1/monitor_wrap.h
@@ -74,16 +74,17 @@ 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);
 #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-6.5p1/packet.c b/openssh-6.5p1/packet.c
--- a/openssh-6.5p1/packet.c
+++ b/openssh-6.5p1/packet.c
@@ -56,16 +56,17 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <signal.h>
 #include <time.h>
 
 #include "xmalloc.h"
+#include "audit.h"
 #include "buffer.h"
 #include "packet.h"
 #include "crc32.h"
 #include "compress.h"
 #include "deattack.h"
 #include "channels.h"
 #include "compat.h"
 #include "ssh1.h"
@@ -469,41 +470,51 @@ packet_get_connection_in(void)
 /* Returns the descriptor used for writing. */
 
 int
 packet_get_connection_out(void)
 {
 	return active_state->connection_out;
 }
 
+static int
+packet_state_has_keys (const struct session_state *state)
+{
+	return state != NULL &&
+		(state->newkeys[MODE_IN] != NULL || state->newkeys[MODE_OUT] != NULL);
+}
+
 /* Closes the connection and clears and frees internal data structures. */
 
 void
 packet_close(void)
 {
 	if (!active_state->initialized)
 		return;
 	active_state->initialized = 0;
-	if (active_state->connection_in == active_state->connection_out) {
-		shutdown(active_state->connection_out, SHUT_RDWR);
-		close(active_state->connection_out);
-	} else {
-		close(active_state->connection_in);
-		close(active_state->connection_out);
-	}
 	buffer_free(&active_state->input);
 	buffer_free(&active_state->output);
 	buffer_free(&active_state->outgoing_packet);
 	buffer_free(&active_state->incoming_packet);
 	if (active_state->compression_buffer_ready) {
 		buffer_free(&active_state->compression_buffer);
 		buffer_compress_uninit();
 	}
-	cipher_cleanup(&active_state->send_context);
-	cipher_cleanup(&active_state->receive_context);
+	if (packet_state_has_keys(active_state)) {
+		cipher_cleanup(&active_state->send_context);
+		cipher_cleanup(&active_state->receive_context);
+		audit_session_key_free(2);
+	}
+	if (active_state->connection_in == active_state->connection_out) {
+		shutdown(active_state->connection_out, SHUT_RDWR);
+		close(active_state->connection_out);
+	} else {
+		close(active_state->connection_in);
+		close(active_state->connection_out);
+	}
 }
 
 /* Sets remote side protocol flags. */
 
 void
 packet_set_protocol_flags(u_int protocol_flags)
 {
 	active_state->remote_protocol_flags = protocol_flags;
@@ -729,16 +740,35 @@ packet_send1(void)
 
 	/*
 	 * Note that the packet is now only buffered in output.  It won't be
 	 * actually sent until packet_write_wait or packet_write_poll is
 	 * called.
 	 */
 }
 
+static void
+newkeys_destroy_and_free(Newkeys *newkeys)
+{
+	if (newkeys == NULL)
+		return;
+
+	free(newkeys->enc.name);
+
+	mac_clear(&newkeys->mac);
+	/* MAC may happen to be empty - if the GCM mode of AES is used */
+	if (newkeys->mac.name)
+		free(newkeys->mac.name);
+
+	free(newkeys->comp.name);
+
+	newkeys_destroy(newkeys);
+	free(newkeys);
+}
+
 void
 set_newkeys(int mode)
 {
 	Enc *enc;
 	Mac *mac;
 	Comp *comp;
 	CipherContext *cc;
 	u_int64_t *max_blocks;
@@ -754,31 +784,19 @@ set_newkeys(int mode)
 	} else {
 		cc = &active_state->receive_context;
 		crypt_type = CIPHER_DECRYPT;
 		active_state->p_read.packets = active_state->p_read.blocks = 0;
 		max_blocks = &active_state->max_blocks_in;
 	}
 	if (active_state->newkeys[mode] != NULL) {
 		debug("set_newkeys: rekeying");
+		audit_session_key_free(mode);
 		cipher_cleanup(cc);
-		enc  = &active_state->newkeys[mode]->enc;
-		mac  = &active_state->newkeys[mode]->mac;
-		comp = &active_state->newkeys[mode]->comp;
-		mac_clear(mac);
-		memset(enc->iv,  0, enc->iv_len);
-		memset(enc->key, 0, enc->key_len);
-		memset(mac->key, 0, mac->key_len);
-		free(enc->name);
-		free(enc->iv);
-		free(enc->key);
-		free(mac->name);
-		free(mac->key);
-		free(comp->name);
-		free(active_state->newkeys[mode]);
+		newkeys_destroy_and_free(active_state->newkeys[mode]);
 	}
 	active_state->newkeys[mode] = kex_get_newkeys(mode);
 	if (active_state->newkeys[mode] == NULL)
 		fatal("newkeys: no keys for mode %d", mode);
 	enc  = &active_state->newkeys[mode]->enc;
 	mac  = &active_state->newkeys[mode]->mac;
 	comp = &active_state->newkeys[mode]->comp;
 	if (cipher_authlen(enc->cipher) == 0 && mac_init(mac) == 0)
@@ -2004,54 +2022,93 @@ packet_get_output(void)
 }
 
 void *
 packet_get_newkeys(int mode)
 {
 	return (void *)active_state->newkeys[mode];
 }
 
+static void
+packet_destroy_state(struct session_state *state)
+{
+	if (state == NULL)
+		return;
+
+	cipher_cleanup(&state->receive_context);
+	cipher_cleanup(&state->send_context);
+
+	buffer_free(&state->input);
+	buffer_free(&state->output);
+	buffer_free(&state->outgoing_packet);
+	buffer_free(&state->incoming_packet);
+	buffer_free(&state->compression_buffer);
+	newkeys_destroy_and_free(state->newkeys[MODE_IN]);
+	state->newkeys[MODE_IN] = NULL;
+	newkeys_destroy_and_free(state->newkeys[MODE_OUT]);
+	state->newkeys[MODE_OUT] = NULL;
+	mac_destroy(state->packet_discard_mac);
+//	TAILQ_HEAD(, packet) outgoing;
+//	memset(state, 0, sizeof(state));
+}
+
+void
+packet_destroy_all(int audit_it, int privsep)
+{
+	if (audit_it)
+		audit_it = packet_state_has_keys (active_state) ||
+			packet_state_has_keys (backup_state);
+	packet_destroy_state(active_state);
+	packet_destroy_state(backup_state);
+	if (audit_it) {
+#ifdef SSH_AUDIT_EVENTS
+		if (privsep)
+			audit_session_key_free(2);
+		else
+			audit_session_key_free_body(2, getpid(), getuid());
+#endif
+	}
+}
+
 /*
  * Save the state for the real connection, and use a separate state when
  * resuming a suspended connection.
  */
 void
 packet_backup_state(void)
 {
-	struct session_state *tmp;
-
 	close(active_state->connection_in);
 	active_state->connection_in = -1;
 	close(active_state->connection_out);
 	active_state->connection_out = -1;
-	if (backup_state)
-		tmp = backup_state;
-	else
-		tmp = alloc_session_state();
 	backup_state = active_state;
-	active_state = tmp;
+	active_state = alloc_session_state();
 }
 
 /*
  * Swap in the old state when resuming a connecion.
  */
 void
 packet_restore_state(void)
 {
 	struct session_state *tmp;
 	void *buf;
 	u_int len;
 
 	tmp = backup_state;
 	backup_state = active_state;
 	active_state = tmp;
 	active_state->connection_in = backup_state->connection_in;
-	backup_state->connection_in = -1;
 	active_state->connection_out = backup_state->connection_out;
-	backup_state->connection_out = -1;
 	len = buffer_len(&backup_state->input);
 	if (len > 0) {
 		buf = buffer_ptr(&backup_state->input);
 		buffer_append(&active_state->input, buf, len);
 		buffer_clear(&backup_state->input);
 		add_recv_bytes(len);
 	}
+	backup_state->connection_in = -1;
+	backup_state->connection_out = -1;
+	packet_destroy_state(backup_state);
+	free(backup_state);
+	backup_state = NULL;
 }
+
diff --git a/openssh-6.5p1/packet.h b/openssh-6.5p1/packet.h
--- a/openssh-6.5p1/packet.h
+++ b/openssh-6.5p1/packet.h
@@ -119,9 +119,10 @@ void	 packet_set_rekey_limits(u_int32_t,
 time_t	 packet_get_rekey_timeout(void);
 
 void	 packet_backup_state(void);
 void	 packet_restore_state(void);
 
 void	*packet_get_input(void);
 void	*packet_get_output(void);
 
+void	 packet_destroy_all(int, int);
 #endif				/* PACKET_H */
diff --git a/openssh-6.5p1/session.c b/openssh-6.5p1/session.c
--- a/openssh-6.5p1/session.c
+++ b/openssh-6.5p1/session.c
@@ -1689,16 +1689,19 @@ do_child(Session *s, const char *command
 	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();
+	/* 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();
 		do_pwchange(s);
 		exit(1);
 	}
diff --git a/openssh-6.5p1/sshd.c b/openssh-6.5p1/sshd.c
--- a/openssh-6.5p1/sshd.c
+++ b/openssh-6.5p1/sshd.c
@@ -711,16 +711,18 @@ privsep_preauth(Authctxt *authctxt)
 		setproctitle("%s", "[net]");
 		if (box != NULL)
 			ssh_sandbox_child(box);
 
 		return 0;
 	}
 }
 
+extern Newkeys *current_keys[];
+
 static void
 privsep_postauth(Authctxt *authctxt)
 {
 	u_int32_t rnd[256];
 
 #ifdef DISABLE_FD_PASSING
 	if (1) {
 #else
@@ -735,16 +737,20 @@ privsep_postauth(Authctxt *authctxt)
 	monitor_reinit(pmonitor);
 
 	pmonitor->m_pid = fork();
 	if (pmonitor->m_pid == -1)
 		fatal("fork of unprivileged child failed");
 	else if (pmonitor->m_pid != 0) {
 		verbose("User child is on pid %ld", (long)pmonitor->m_pid);
 		buffer_clear(&loginmsg);
+ 		newkeys_destroy(current_keys[MODE_OUT]);
+		newkeys_destroy(current_keys[MODE_IN]);
+		audit_session_key_free_body(2, getpid(), getuid());
+		packet_destroy_all(0, 0);
 		monitor_child_postauth(pmonitor);
 
 		/* NEVERREACHED */
 		exit(0);
 	}
 
 	/* child */
 
@@ -2104,16 +2110,17 @@ main(int ac, char **av)
 		do_authentication(authctxt);
 	}
 	/*
 	 * If we use privilege separation, the unprivileged child transfers
 	 * the current keystate and exits
 	 */
 	if (use_privsep) {
 		mm_send_keystate(pmonitor);
+		packet_destroy_all(1, 1);
 		exit(0);
 	}
 
  authenticated:
 	/*
 	 * Cancel the alarm we set to limit the time taken for
 	 * authentication.
 	 */
@@ -2156,16 +2163,18 @@ main(int ac, char **av)
 
 	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);
+
 	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);
 
 #ifdef USE_PAM
@@ -2497,26 +2506,38 @@ do_ssh2_kex(void)
 #endif
 	debug("KEX done");
 }
 
 /* server specific fatal cleanup */
 void
 cleanup_exit(int i)
 {
+	static int in_cleanup = 0;
+	int is_privsep_child;
+
+	/* cleanup_exit can be called at the very least from the privsep
+	   wrappers used for auditing.  Make sure we don't recurse
+	   indefinitely. */
+	if (in_cleanup)
+		_exit(i);
+	in_cleanup = 1;
+
 	if (the_authctxt) {
 		do_cleanup(the_authctxt);
 		if (use_privsep && privsep_is_preauth && pmonitor->m_pid > 1) {
 			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();
+	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);
 }