1 files changed, 170 insertions, 160 deletions

diff --git a/packet.c b/packet.c
index d6dad2da6..ad1f6b497 100644
--- a/packet.c
+++ b/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.234 2016/07/18 11:35:33 markus Exp $ */
+/* $OpenBSD: packet.c,v 1.243 2016/10/11 21:47:45 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -38,8 +38,7 @@
  */
 
 #include "includes.h"
- 
-#include <sys/param.h>  /* MIN roundup */
+
 #include <sys/types.h>
 #include "openbsd-compat/sys-queue.h"
 #include <sys/socket.h>
@@ -122,10 +121,10 @@ struct session_state {
         u_int remote_protocol_flags;
 
         /* Encryption context for receiving data.  Only used for decryption. */
-        struct sshcipher_ctx receive_context;
+        struct sshcipher_ctx *receive_context;
 
         /* Encryption context for sending data.  Only used for encryption. */
-        struct sshcipher_ctx send_context;
+        struct sshcipher_ctx *send_context;
 
         /* Buffer for raw input data from the socket. */
         struct sshbuf *input;
@@ -205,6 +204,9 @@ struct session_state {
         /* Used in packet_send2 */
         int rekeying;
 
+        /* Used in ssh_packet_send_mux() */
+        int mux;
+
         /* Used in packet_set_interactive */
         int set_interactive_called;
 
@@ -217,6 +219,10 @@ struct session_state {
         /* SSH1 CRC compensation attack detector */
         struct deattack_ctx deattack;
 
+        /* Hook for fuzzing inbound packets */
+        ssh_packet_hook_fn *hook_in;
+        void *hook_in_ctx;
+
         TAILQ_HEAD(, packet) outgoing;
 };
 
@@ -261,6 +267,13 @@ ssh_alloc_session_state(void)
         return NULL;
 }
 
+void
+ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
+{
+        ssh->state->hook_in = hook;
+        ssh->state->hook_in_ctx = ctx;
+}
+
 /* Returns nonzero if rekeying is in progress */
 int
 ssh_packet_is_rekeying(struct ssh *ssh)
@@ -326,6 +339,19 @@ ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
                 state->packet_timeout_ms = timeout * count * 1000;
 }
 
+void
+ssh_packet_set_mux(struct ssh *ssh)
+{
+        ssh->state->mux = 1;
+        ssh->state->rekeying = 0;
+}
+
+int
+ssh_packet_get_mux(struct ssh *ssh)
+{
+        return ssh->state->mux;
+}
+
 int
 ssh_packet_stop_discard(struct ssh *ssh)
 {
@@ -529,7 +555,6 @@ void
 ssh_packet_close(struct ssh *ssh)
 {
         struct session_state *state = ssh->state;
-        int r;
         u_int mode;
 
         if (!state->initialized)
@@ -573,10 +598,9 @@ ssh_packet_close(struct ssh *ssh)
                                 inflateEnd(stream);
                 }
         }
-        if ((r = cipher_cleanup(&state->send_context)) != 0)
-                error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
-        if ((r = cipher_cleanup(&state->receive_context)) != 0)
-                error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
+        cipher_free(state->send_context);
+        cipher_free(state->receive_context);
+        state->send_context = state->receive_context = NULL;
         free(ssh->remote_ipaddr);
         ssh->remote_ipaddr = NULL;
         free(ssh->state);
@@ -759,86 +783,6 @@ uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
         /* NOTREACHED */
 }
 
-/* Serialise compression state into a blob for privsep */
-static int
-ssh_packet_get_compress_state(struct sshbuf *m, struct ssh *ssh)
-{
-        struct session_state *state = ssh->state;
-        struct sshbuf *b;
-        int r;
-
-        if ((b = sshbuf_new()) == NULL)
-                return SSH_ERR_ALLOC_FAIL;
-        if (state->compression_in_started) {
-                if ((r = sshbuf_put_string(b, &state->compression_in_stream,
-                    sizeof(state->compression_in_stream))) != 0)
-                        goto out;
-        } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
-                goto out;
-        if (state->compression_out_started) {
-                if ((r = sshbuf_put_string(b, &state->compression_out_stream,
-                    sizeof(state->compression_out_stream))) != 0)
-                        goto out;
-        } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
-                goto out;
-        r = sshbuf_put_stringb(m, b);
- out:
-        sshbuf_free(b);
-        return r;
-}
-
-/* Deserialise compression state from a blob for privsep */
-static int
-ssh_packet_set_compress_state(struct ssh *ssh, struct sshbuf *m)
-{
-        struct session_state *state = ssh->state;
-        struct sshbuf *b = NULL;
-        int r;
-        const u_char *inblob, *outblob;
-        size_t inl, outl;
-
-        if ((r = sshbuf_froms(m, &b)) != 0)
-                goto out;
-        if ((r = sshbuf_get_string_direct(b, &inblob, &inl)) != 0 ||
-            (r = sshbuf_get_string_direct(b, &outblob, &outl)) != 0)
-                goto out;
-        if (inl == 0)
-                state->compression_in_started = 0;
-        else if (inl != sizeof(state->compression_in_stream)) {
-                r = SSH_ERR_INTERNAL_ERROR;
-                goto out;
-        } else {
-                state->compression_in_started = 1;
-                memcpy(&state->compression_in_stream, inblob, inl);
-        }
-        if (outl == 0)
-                state->compression_out_started = 0;
-        else if (outl != sizeof(state->compression_out_stream)) {
-                r = SSH_ERR_INTERNAL_ERROR;
-                goto out;
-        } else {
-                state->compression_out_started = 1;
-                memcpy(&state->compression_out_stream, outblob, outl);
-        }
-        r = 0;
- out:
-        sshbuf_free(b);
-        return r;
-}
-
-void
-ssh_packet_set_compress_hooks(struct ssh *ssh, void *ctx,
-    void *(*allocfunc)(void *, u_int, u_int),
-    void (*freefunc)(void *, void *))
-{
-        ssh->state->compression_out_stream.zalloc = (alloc_func)allocfunc;
-        ssh->state->compression_out_stream.zfree = (free_func)freefunc;
-        ssh->state->compression_out_stream.opaque = ctx;
-        ssh->state->compression_in_stream.zalloc = (alloc_func)allocfunc;
-        ssh->state->compression_in_stream.zfree = (free_func)freefunc;
-        ssh->state->compression_in_stream.opaque = ctx;
-}
-
 /*
  * Causes any further packets to be encrypted using the given key.  The same
  * key is used for both sending and reception.  However, both directions are
@@ -870,8 +814,8 @@ ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen,
             NULL, 0, CIPHER_DECRYPT) != 0))
                 fatal("%s: cipher_init failed: %s", __func__, ssh_err(r));
         if (!state->cipher_warning_done &&
-            ((wmsg = cipher_warning_message(&state->send_context)) != NULL ||
-            (wmsg = cipher_warning_message(&state->send_context)) != NULL)) {
+            ((wmsg = cipher_warning_message(state->send_context)) != NULL ||
+            (wmsg = cipher_warning_message(state->send_context)) != NULL)) {
                 error("Warning: %s", wmsg);
                 state->cipher_warning_done = 1;
         }
@@ -917,7 +861,7 @@ ssh_packet_send1(struct ssh *ssh)
 
         /* Insert padding. Initialized to zero in packet_start1() */
         padding = 8 - len % 8;
-        if (!state->send_context.plaintext) {
+        if (!cipher_ctx_is_plaintext(state->send_context)) {
                 cp = sshbuf_mutable_ptr(state->outgoing_packet);
                 if (cp == NULL) {
                         r = SSH_ERR_INTERNAL_ERROR;
@@ -947,7 +891,7 @@ ssh_packet_send1(struct ssh *ssh)
         if ((r = sshbuf_reserve(state->output,
             sshbuf_len(state->outgoing_packet), &cp)) != 0)
                 goto out;
-        if ((r = cipher_crypt(&state->send_context, 0, cp,
+        if ((r = cipher_crypt(state->send_context, 0, cp,
             sshbuf_ptr(state->outgoing_packet),
             sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
                 goto out;
@@ -978,33 +922,34 @@ ssh_set_newkeys(struct ssh *ssh, int mode)
         struct sshenc *enc;
         struct sshmac *mac;
         struct sshcomp *comp;
-        struct sshcipher_ctx *cc;
+        struct sshcipher_ctx **ccp;
+        struct packet_state *ps;
         u_int64_t *max_blocks;
-        const char *wmsg;
+        const char *wmsg, *dir;
         int r, crypt_type;
 
         debug2("set_newkeys: mode %d", mode);
 
         if (mode == MODE_OUT) {
-                cc = &state->send_context;
+                dir = "output";
+                ccp = &state->send_context;
                 crypt_type = CIPHER_ENCRYPT;
-                state->p_send.packets = state->p_send.blocks = 0;
+                ps = &state->p_send;
                 max_blocks = &state->max_blocks_out;
         } else {
-                cc = &state->receive_context;
+                dir = "input";
+                ccp = &state->receive_context;
                 crypt_type = CIPHER_DECRYPT;
-                state->p_read.packets = state->p_read.blocks = 0;
+                ps = &state->p_read;
                 max_blocks = &state->max_blocks_in;
         }
         if (state->newkeys[mode] != NULL) {
-                debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
-                   "output %llu bytes %llu blocks",
-                   (unsigned long long)state->p_read.bytes,
-                   (unsigned long long)state->p_read.blocks,
-                   (unsigned long long)state->p_send.bytes,
-                   (unsigned long long)state->p_send.blocks);
-                if ((r = cipher_cleanup(cc)) != 0)
-                        return r;
+                debug("%s: rekeying after %llu %s blocks"
+                    " (%llu bytes total)", __func__,
+                    (unsigned long long)ps->blocks, dir,
+                    (unsigned long long)ps->bytes);
+                cipher_free(*ccp);
+                *ccp = NULL;
                 enc  = &state->newkeys[mode]->enc;
                 mac  = &state->newkeys[mode]->mac;
                 comp = &state->newkeys[mode]->comp;
@@ -1020,6 +965,8 @@ ssh_set_newkeys(struct ssh *ssh, int mode)
                 free(comp->name);
                 free(state->newkeys[mode]);
         }
+        /* note that both bytes and the seqnr are not reset */
+        ps->packets = ps->blocks = 0;
         /* move newkeys from kex to state */
         if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
                 return SSH_ERR_INTERNAL_ERROR;
@@ -1033,11 +980,11 @@ ssh_set_newkeys(struct ssh *ssh, int mode)
         }
         mac->enabled = 1;
         DBG(debug("cipher_init_context: %d", mode));
-        if ((r = cipher_init(cc, enc->cipher, enc->key, enc->key_len,
+        if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
             enc->iv, enc->iv_len, crypt_type)) != 0)
                 return r;
         if (!state->cipher_warning_done &&
-            (wmsg = cipher_warning_message(cc)) != NULL) {
+            (wmsg = cipher_warning_message(*ccp)) != NULL) {
                 error("Warning: %s", wmsg);
                 state->cipher_warning_done = 1;
         }
@@ -1068,7 +1015,7 @@ ssh_set_newkeys(struct ssh *ssh, int mode)
         else
                 *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
         if (state->rekey_limit)
-                *max_blocks = MIN(*max_blocks,
+                *max_blocks = MINIMUM(*max_blocks,
                     state->rekey_limit / enc->block_size);
         debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
         return 0;
@@ -1111,7 +1058,7 @@ ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
                 return 1;
 
         /* Rekey after (cipher-specific) maxiumum blocks */
-        out_blocks = roundup(outbound_packet_len,
+        out_blocks = ROUNDUP(outbound_packet_len,
             state->newkeys[MODE_OUT]->enc.block_size);
         return (state->max_blocks_out &&
             (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
@@ -1158,7 +1105,7 @@ ssh_packet_enable_delayed_compress(struct ssh *ssh)
 }
 
 /* Used to mute debug logging for noisy packet types */
-static int
+int
 ssh_packet_log_type(u_char type)
 {
         switch (type) {
@@ -1239,7 +1186,7 @@ ssh_packet_send2_wrapped(struct ssh *ssh)
         if (state->extra_pad) {
                 tmp = state->extra_pad;
                 state->extra_pad =
-                    roundup(state->extra_pad, block_size);
+                    ROUNDUP(state->extra_pad, block_size);
                 /* check if roundup overflowed */
                 if (state->extra_pad < tmp)
                         return SSH_ERR_INVALID_ARGUMENT;
@@ -1259,7 +1206,7 @@ ssh_packet_send2_wrapped(struct ssh *ssh)
         }
         if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
                 goto out;
-        if (enc && !state->send_context.plaintext) {
+        if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
                 /* random padding */
                 arc4random_buf(cp, padlen);
         } else {
@@ -1291,7 +1238,7 @@ ssh_packet_send2_wrapped(struct ssh *ssh)
         if ((r = sshbuf_reserve(state->output,
             sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
                 goto out;
-        if ((r = cipher_crypt(&state->send_context, state->p_send.seqnr, cp,
+        if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
             sshbuf_ptr(state->outgoing_packet),
             len - aadlen, aadlen, authlen)) != 0)
                 goto out;
@@ -1606,7 +1553,7 @@ ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
          * (C)1998 CORE-SDI, Buenos Aires Argentina
          * Ariel Futoransky(futo@core-sdi.com)
          */
-        if (!state->receive_context.plaintext) {
+        if (!cipher_ctx_is_plaintext(state->receive_context)) {
                 emsg = NULL;
                 switch (detect_attack(&state->deattack,
                     sshbuf_ptr(state->input), padded_len)) {
@@ -1635,7 +1582,7 @@ ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
         sshbuf_reset(state->incoming_packet);
         if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
                 goto out;
-        if ((r = cipher_crypt(&state->receive_context, 0, p,
+        if ((r = cipher_crypt(state->receive_context, 0, p,
             sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
                 goto out;
 
@@ -1703,6 +1650,44 @@ ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
         return r;
 }
 
+static int
+ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
+{
+        struct session_state *state = ssh->state;
+        const u_char *cp;
+        size_t need;
+        int r;
+
+        if (ssh->kex)
+                return SSH_ERR_INTERNAL_ERROR;
+        *typep = SSH_MSG_NONE;
+        cp = sshbuf_ptr(state->input);
+        if (state->packlen == 0) {
+                if (sshbuf_len(state->input) < 4 + 1)
+                        return 0; /* packet is incomplete */
+                state->packlen = PEEK_U32(cp);
+                if (state->packlen < 4 + 1 ||
+                    state->packlen > PACKET_MAX_SIZE)
+                        return SSH_ERR_MESSAGE_INCOMPLETE;
+        }
+        need = state->packlen + 4;
+        if (sshbuf_len(state->input) < need)
+                return 0; /* packet is incomplete */
+        sshbuf_reset(state->incoming_packet);
+        if ((r = sshbuf_put(state->incoming_packet, cp + 4,
+            state->packlen)) != 0 ||
+            (r = sshbuf_consume(state->input, need)) != 0 ||
+            (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
+            (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
+                return r;
+        if (ssh_packet_log_type(*typep))
+                debug3("%s: type %u", __func__, *typep);
+        /* sshbuf_dump(state->incoming_packet, stderr); */
+        /* reset for next packet */
+        state->packlen = 0;
+        return r;
+}
+
 int
 ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
 {
@@ -1715,6 +1700,9 @@ ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
         struct sshcomp *comp = NULL;
         int r;
 
+        if (state->mux)
+                return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
+
         *typep = SSH_MSG_NONE;
 
         if (state->packet_discard)
@@ -1733,7 +1721,7 @@ ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
         aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
 
         if (aadlen && state->packlen == 0) {
-                if (cipher_get_length(&state->receive_context,
+                if (cipher_get_length(state->receive_context,
                     &state->packlen, state->p_read.seqnr,
                     sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
                         return 0;
@@ -1759,7 +1747,7 @@ ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
                 if ((r = sshbuf_reserve(state->incoming_packet, block_size,
                     &cp)) != 0)
                         goto out;
-                if ((r = cipher_crypt(&state->receive_context,
+                if ((r = cipher_crypt(state->receive_context,
                     state->p_send.seqnr, cp, sshbuf_ptr(state->input),
                     block_size, 0, 0)) != 0)
                         goto out;
@@ -1827,7 +1815,7 @@ ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
         if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
             &cp)) != 0)
                 goto out;
-        if ((r = cipher_crypt(&state->receive_context, state->p_read.seqnr, cp,
+        if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
             sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
                 goto out;
         if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
@@ -1907,9 +1895,11 @@ ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
                         return r;
                 return SSH_ERR_PROTOCOL_ERROR;
         }
-        if (*typep == SSH2_MSG_NEWKEYS)
-                r = ssh_set_newkeys(ssh, MODE_IN);
-        else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
+        if (state->hook_in != NULL &&
+            (r = state->hook_in(ssh, state->incoming_packet, typep,
+            state->hook_in_ctx)) != 0)
+                return r;
+        if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
                 r = ssh_packet_enable_delayed_compress(ssh);
         else
                 r = 0;
@@ -2452,21 +2442,14 @@ ssh_packet_get_output(struct ssh *ssh)
 static int
 ssh_packet_set_postauth(struct ssh *ssh)
 {
-        struct sshcomp *comp;
-        int r, mode;
+        int r;
 
         debug("%s: called", __func__);
         /* This was set in net child, but is not visible in user child */
         ssh->state->after_authentication = 1;
         ssh->state->rekeying = 0;
-        for (mode = 0; mode < MODE_MAX; mode++) {
-                if (ssh->state->newkeys[mode] == NULL)
-                        continue;
-                comp = &ssh->state->newkeys[mode]->comp;
-                if (comp && comp->enabled &&
-                    (r = ssh_packet_init_compression(ssh)) != 0)
-                        return r;
-        }
+        if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
+                return r;
         return 0;
 }
 
@@ -2509,8 +2492,8 @@ newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
         enc = &newkey->enc;
         mac = &newkey->mac;
         comp = &newkey->comp;
-        cc = (mode == MODE_OUT) ? &ssh->state->send_context :
-            &ssh->state->receive_context;
+        cc = (mode == MODE_OUT) ? ssh->state->send_context :
+            ssh->state->receive_context;
         if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
                 return r;
         if ((b = sshbuf_new()) == NULL)
@@ -2530,7 +2513,6 @@ newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
                         goto out;
         }
         if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
-            (r = sshbuf_put_u32(b, comp->enabled)) != 0 ||
             (r = sshbuf_put_cstring(b, comp->name)) != 0)
                 goto out;
         r = sshbuf_put_stringb(m, b);
@@ -2549,18 +2531,18 @@ ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
         int r, ssh1cipher;
 
         if (!compat20) {
-                ssh1cipher = cipher_get_number(state->receive_context.cipher);
-                slen = cipher_get_keyiv_len(&state->send_context);
-                rlen = cipher_get_keyiv_len(&state->receive_context);
+                ssh1cipher = cipher_ctx_get_number(state->receive_context);
+                slen = cipher_get_keyiv_len(state->send_context);
+                rlen = cipher_get_keyiv_len(state->receive_context);
                 if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
                     (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
                     (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
                     (r = sshbuf_put_u32(m, slen)) != 0 ||
                     (r = sshbuf_reserve(m, slen, &p)) != 0 ||
-                    (r = cipher_get_keyiv(&state->send_context, p, slen)) != 0 ||
+                    (r = cipher_get_keyiv(state->send_context, p, slen)) != 0 ||
                     (r = sshbuf_put_u32(m, rlen)) != 0 ||
                     (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
-                    (r = cipher_get_keyiv(&state->receive_context, p, rlen)) != 0)
+                    (r = cipher_get_keyiv(state->receive_context, p, rlen)) != 0)
                         return r;
         } else {
                 if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
@@ -2579,21 +2561,19 @@ ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
                         return r;
         }
 
-        slen = cipher_get_keycontext(&state->send_context, NULL);
-        rlen = cipher_get_keycontext(&state->receive_context, NULL);
+        slen = cipher_get_keycontext(state->send_context, NULL);
+        rlen = cipher_get_keycontext(state->receive_context, NULL);
         if ((r = sshbuf_put_u32(m, slen)) != 0 ||
             (r = sshbuf_reserve(m, slen, &p)) != 0)
                 return r;
-        if (cipher_get_keycontext(&state->send_context, p) != (int)slen)
+        if (cipher_get_keycontext(state->send_context, p) != (int)slen)
                 return SSH_ERR_INTERNAL_ERROR;
         if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
             (r = sshbuf_reserve(m, rlen, &p)) != 0)
                 return r;
-        if (cipher_get_keycontext(&state->receive_context, p) != (int)rlen)
+        if (cipher_get_keycontext(state->receive_context, p) != (int)rlen)
                 return SSH_ERR_INTERNAL_ERROR;
-
-        if ((r = ssh_packet_get_compress_state(m, ssh)) != 0 ||
-            (r = sshbuf_put_stringb(m, state->input)) != 0 ||
+        if ((r = sshbuf_put_stringb(m, state->input)) != 0 ||
             (r = sshbuf_put_stringb(m, state->output)) != 0)
                 return r;
 
@@ -2647,7 +2627,6 @@ newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
                 mac->key_len = maclen;
         }
         if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
-            (r = sshbuf_get_u32(b, (u_int *)&comp->enabled)) != 0 ||
             (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
                 goto out;
         if (enc->name == NULL ||
@@ -2735,11 +2714,11 @@ ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
                         return SSH_ERR_KEY_UNKNOWN_CIPHER;
                 ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
                     (int)ssh1cipher);
-                if (cipher_get_keyiv_len(&state->send_context) != (int)slen ||
-                    cipher_get_keyiv_len(&state->receive_context) != (int)rlen)
+                if (cipher_get_keyiv_len(state->send_context) != (int)slen ||
+                    cipher_get_keyiv_len(state->receive_context) != (int)rlen)
                         return SSH_ERR_INVALID_FORMAT;
-                if ((r = cipher_set_keyiv(&state->send_context, ivout)) != 0 ||
-                    (r = cipher_set_keyiv(&state->receive_context, ivin)) != 0)
+                if ((r = cipher_set_keyiv(state->send_context, ivout)) != 0 ||
+                    (r = cipher_set_keyiv(state->receive_context, ivin)) != 0)
                         return r;
         } else {
                 if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
@@ -2769,14 +2748,13 @@ ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
         if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
             (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
                 return r;
-        if (cipher_get_keycontext(&state->send_context, NULL) != (int)slen ||
-            cipher_get_keycontext(&state->receive_context, NULL) != (int)rlen)
+        if (cipher_get_keycontext(state->send_context, NULL) != (int)slen ||
+            cipher_get_keycontext(state->receive_context, NULL) != (int)rlen)
                 return SSH_ERR_INVALID_FORMAT;
-        cipher_set_keycontext(&state->send_context, keyout);
-        cipher_set_keycontext(&state->receive_context, keyin);
+        cipher_set_keycontext(state->send_context, keyout);
+        cipher_set_keycontext(state->receive_context, keyin);
 
-        if ((r = ssh_packet_set_compress_state(ssh, m)) != 0 ||
-            (r = ssh_packet_set_postauth(ssh)) != 0)
+        if ((r = ssh_packet_set_postauth(ssh)) != 0)
                 return r;
 
         sshbuf_reset(state->input);
@@ -2969,11 +2947,43 @@ sshpkt_start(struct ssh *ssh, u_char type)
         return sshbuf_put(ssh->state->outgoing_packet, buf, len);
 }
 
+static int
+ssh_packet_send_mux(struct ssh *ssh)
+{
+        struct session_state *state = ssh->state;
+        u_char type, *cp;
+        size_t len;
+        int r;
+
+        if (ssh->kex)
+                return SSH_ERR_INTERNAL_ERROR;
+        len = sshbuf_len(state->outgoing_packet);
+        if (len < 6)
+                return SSH_ERR_INTERNAL_ERROR;
+        cp = sshbuf_mutable_ptr(state->outgoing_packet);
+        type = cp[5];
+        if (ssh_packet_log_type(type))
+                debug3("%s: type %u", __func__, type);
+        /* drop everything, but the connection protocol */
+        if (type >= SSH2_MSG_CONNECTION_MIN &&
+            type <= SSH2_MSG_CONNECTION_MAX) {
+                POKE_U32(cp, len - 4);
+                if ((r = sshbuf_putb(state->output,
+                    state->outgoing_packet)) != 0)
+                        return r;
+                /* sshbuf_dump(state->output, stderr); */
+        }
+        sshbuf_reset(state->outgoing_packet);
+        return 0;
+}
+
 /* send it */
 
 int
 sshpkt_send(struct ssh *ssh)
 {
+        if (ssh->state && ssh->state->mux)
+                return ssh_packet_send_mux(ssh);
         if (compat20)
                 return ssh_packet_send2(ssh);
         else