- markus@cvs.openbsd.org 2002/06/19 18:01:00

     [cipher.c monitor.c monitor_wrap.c packet.c packet.h]
     make the monitor sync the transfer ssh1 session key;
     transfer keycontext only for RC4 (this is still depends on EVP
     implementation details and is broken).

6 files changed, 55 insertions, 42 deletions

diff --git a/ChangeLog b/ChangeLog
index 56847778..664f8626 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -30,6 +30,11 @@
       ssh-keysign.c ssh.1 sshconnect.c sshconnect.h sshconnect2.c ttymodes.c
       xmalloc.h]
      KNF done automatically while reading....
+   - markus@cvs.openbsd.org 2002/06/19 18:01:00
+     [cipher.c monitor.c monitor_wrap.c packet.c packet.h]
+     make the monitor sync the transfer ssh1 session key;
+     transfer keycontext only for RC4 (this is still depends on EVP
+     implementation details and is broken).
  - (bal) Cygwin special handling of empty passwords wrong.  Patch by
    vinschen@redhat.com
 
@@ -960,4 +965,4 @@
  - (stevesk) entropy.c: typo in debug message
  - (djm) ssh-keygen -i needs seeded RNG; report from markus@
 
-$Id: ChangeLog,v 1.2225 2002/06/21 00:41:51 mouring Exp $
+$Id: ChangeLog,v 1.2226 2002/06/21 00:43:42 mouring Exp $
diff --git a/cipher.c b/cipher.c
index 39807d5c..b18c701f 100644
--- a/cipher.c
+++ b/cipher.c
@@ -35,7 +35,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: cipher.c,v 1.58 2002/06/04 23:05:49 markus Exp $");
+RCSID("$OpenBSD: cipher.c,v 1.59 2002/06/19 18:01:00 markus Exp $");
 
 #include "xmalloc.h"
 #include "log.h"
@@ -689,28 +689,14 @@ int
 cipher_get_keycontext(CipherContext *cc, u_char *dat)
 {
 	Cipher *c = cc->cipher;
-	int plen;
+	int plen = 0;
 
-	if (c->number == SSH_CIPHER_3DES) {
-		struct ssh1_3des_ctx *desc;
-		desc = EVP_CIPHER_CTX_get_app_data(&cc->evp);
-		if (desc == NULL)
-			fatal("%s: no 3des context", __func__);
-		plen = EVP_X_STATE_LEN(desc->k1);
+	if (c->evptype == EVP_rc4) {
+		plen = EVP_X_STATE_LEN(cc->evp);
 		if (dat == NULL)
-			return (3*plen);
-		memcpy(dat, EVP_X_STATE(desc->k1), plen);
-		memcpy(dat + plen, EVP_X_STATE(desc->k2), plen);
-		memcpy(dat + 2*plen, EVP_X_STATE(desc->k3), plen);
-		return (3*plen);
+			return (plen);
+		memcpy(dat, EVP_X_STATE(cc->evp), plen);
 	}
-
-	/* Generic EVP */
-	plen = EVP_X_STATE_LEN(cc->evp);
-	if (dat == NULL)
-		return (plen);
-
-	memcpy(dat, EVP_X_STATE(cc->evp), plen);
 	return (plen);
 }
 
@@ -720,16 +706,7 @@ cipher_set_keycontext(CipherContext *cc, u_char *dat)
 	Cipher *c = cc->cipher;
 	int plen;
 
-	if (c->number == SSH_CIPHER_3DES) {
-		struct ssh1_3des_ctx *desc;
-		desc = EVP_CIPHER_CTX_get_app_data(&cc->evp);
-		if (desc == NULL)
-			fatal("%s: no 3des context", __func__);
-		plen = EVP_X_STATE_LEN(desc->k1);
-		memcpy(EVP_X_STATE(desc->k1), dat, plen);
-		memcpy(EVP_X_STATE(desc->k2), dat + plen, plen);
-		memcpy(EVP_X_STATE(desc->k3), dat + 2*plen, plen);
-	} else {
+	if (c->evptype == EVP_rc4) {
 		plen = EVP_X_STATE_LEN(cc->evp);
 		memcpy(EVP_X_STATE(cc->evp), dat, plen);
 	}
diff --git a/monitor.c b/monitor.c
index 39009f70..c769f12e 100644
--- a/monitor.c
+++ b/monitor.c
@@ -25,7 +25,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: monitor.c,v 1.14 2002/06/04 23:05:49 markus Exp $");
+RCSID("$OpenBSD: monitor.c,v 1.15 2002/06/19 18:01:00 markus Exp $");
 
 #include <openssl/dh.h>
 
@@ -83,6 +83,8 @@ struct {
 	u_int ivinlen;
 	u_char *ivout;
 	u_int ivoutlen;
+	u_char *ssh1key;
+	u_int ssh1keylen;
 	int ssh1cipher;
 	int ssh1protoflags;
 	u_char *input;
@@ -1303,14 +1305,13 @@ monitor_apply_keystate(struct monitor *pmonitor)
 		set_newkeys(MODE_IN);
 		set_newkeys(MODE_OUT);
 	} else {
-		u_char key[SSH_SESSION_KEY_LENGTH];
-
-		memset(key, 'a', sizeof(key));
 		packet_set_protocol_flags(child_state.ssh1protoflags);
-		packet_set_encryption_key(key, SSH_SESSION_KEY_LENGTH,
-		    child_state.ssh1cipher);
+		packet_set_encryption_key(child_state.ssh1key,
+		    child_state.ssh1keylen, child_state.ssh1cipher);
+		xfree(child_state.ssh1key);
 	}
 
+	/* for rc4 and other stateful ciphers */
 	packet_set_keycontext(MODE_OUT, child_state.keyout);
 	xfree(child_state.keyout);
 	packet_set_keycontext(MODE_IN, child_state.keyin);
@@ -1396,6 +1397,8 @@ mm_get_keystate(struct monitor *pmonitor)
 	if (!compat20) {
 		child_state.ssh1protoflags = buffer_get_int(&m);
 		child_state.ssh1cipher = buffer_get_int(&m);
+		child_state.ssh1key = buffer_get_string(&m,
+		    &child_state.ssh1keylen);
 		child_state.ivout = buffer_get_string(&m,
 		    &child_state.ivoutlen);
 		child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
diff --git a/monitor_wrap.c b/monitor_wrap.c
index e4087462..f7e332d8 100644
--- a/monitor_wrap.c
+++ b/monitor_wrap.c
@@ -25,7 +25,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: monitor_wrap.c,v 1.10 2002/06/19 00:27:55 deraadt Exp $");
+RCSID("$OpenBSD: monitor_wrap.c,v 1.11 2002/06/19 18:01:00 markus Exp $");
 
 #include <openssl/bn.h>
 #include <openssl/dh.h>
@@ -520,13 +520,21 @@ mm_send_keystate(struct monitor *pmonitor)
 
 	if (!compat20) {
 		u_char iv[24];
-		int ivlen;
+		u_char *key;
+		u_int ivlen, keylen;
 
 		buffer_put_int(&m, packet_get_protocol_flags());
 
 		buffer_put_int(&m, packet_get_ssh1_cipher());
 
-		debug3("%s: Sending ssh1 IV", __func__);
+		debug3("%s: Sending ssh1 KEY+IV", __func__);
+		keylen = packet_get_encryption_key(NULL);
+		key = xmalloc(keylen+1);	/* add 1 if keylen == 0 */
+		keylen = packet_get_encryption_key(key);
+		buffer_put_string(&m, key, keylen);
+		memset(key, 0, keylen);
+		xfree(key);
+
 		ivlen = packet_get_keyiv_len(MODE_OUT);
 		packet_get_keyiv(MODE_OUT, iv, ivlen);
 		buffer_put_string(&m, iv, ivlen);
diff --git a/packet.c b/packet.c
index abc89e76..86511276 100644
--- a/packet.c
+++ b/packet.c
@@ -37,7 +37,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: packet.c,v 1.94 2002/06/04 23:02:06 markus Exp $");
+RCSID("$OpenBSD: packet.c,v 1.95 2002/06/19 18:01:00 markus Exp $");
 
 #include "xmalloc.h"
 #include "buffer.h"
@@ -60,6 +60,7 @@ RCSID("$OpenBSD: packet.c,v 1.94 2002/06/04 23:02:06 markus Exp $");
 #include "log.h"
 #include "canohost.h"
 #include "misc.h"
+#include "ssh.h"
 
 #ifdef PACKET_DEBUG
 #define DBG(x) x
@@ -118,6 +119,10 @@ Newkeys *newkeys[MODE_MAX];
 static u_int32_t read_seqnr = 0;
 static u_int32_t send_seqnr = 0;
 
+/* Session key for protocol v1 */
+static u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
+static u_int ssh1_keylen;
+
 /* roundup current message to extra_pad bytes */
 static u_char extra_pad = 0;
 
@@ -391,6 +396,7 @@ packet_start_compression(int level)
  * key is used for both sending and reception.  However, both directions are
  * encrypted independently of each other.
  */
+
 void
 packet_set_encryption_key(const u_char *key, u_int keylen,
     int number)
@@ -400,10 +406,23 @@ packet_set_encryption_key(const u_char *key, u_int keylen,
 		fatal("packet_set_encryption_key: unknown cipher number %d", number);
 	if (keylen < 20)
 		fatal("packet_set_encryption_key: keylen too small: %d", keylen);
+	if (keylen > SSH_SESSION_KEY_LENGTH)
+		fatal("packet_set_encryption_key: keylen too big: %d", keylen);
+	memcpy(ssh1_key, key, keylen);
+	ssh1_keylen = keylen;
 	cipher_init(&send_context, cipher, key, keylen, NULL, 0, CIPHER_ENCRYPT);
 	cipher_init(&receive_context, cipher, key, keylen, NULL, 0, CIPHER_DECRYPT);
 }
 
+u_int
+packet_get_encryption_key(u_char *key)
+{
+	if (key == NULL)
+		return (ssh1_keylen);
+	memcpy(key, ssh1_key, ssh1_keylen);
+	return (ssh1_keylen);
+}
+
 /* Start constructing a packet to send. */
 void
 packet_start(u_char type)
diff --git a/packet.h b/packet.h
index 151ca74a..3ff75593 100644
--- a/packet.h
+++ b/packet.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: packet.h,v 1.34 2002/03/18 17:16:38 markus Exp $	*/
+/*	$OpenBSD: packet.h,v 1.35 2002/06/19 18:01:00 markus Exp $	*/
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -24,6 +24,7 @@ int      packet_get_connection_in(void);
 int      packet_get_connection_out(void);
 void     packet_close(void);
 void	 packet_set_encryption_key(const u_char *, u_int, int);
+u_int	 packet_get_encryption_key(u_char *);
 void     packet_set_protocol_flags(u_int);
 u_int	 packet_get_protocol_flags(void);
 void     packet_start_compression(int);