5 files changed, 144 insertions, 151 deletions

diff --git a/usr.bin/ssh/kex.c b/usr.bin/ssh/kex.c
index c10c77ead60..a6c8174a425 100644
--- a/usr.bin/ssh/kex.c
+++ b/usr.bin/ssh/kex.c
@@ -28,13 +28,14 @@
  */
 
 #include "includes.h"
-RCSID("$Id: kex.c,v 1.6 2000/05/08 17:42:25 markus Exp $");
+RCSID("$Id: kex.c,v 1.7 2000/05/25 20:45:20 markus Exp $");
 
 #include "ssh.h"
 #include "ssh2.h"
 #include "xmalloc.h"
 #include "buffer.h"
 #include "bufaux.h"
+#include "packet.h"
 #include "cipher.h"
 #include "compat.h"
 
@@ -49,15 +50,17 @@ RCSID("$Id: kex.c,v 1.6 2000/05/08 17:42:25 markus Exp $");
 
 #include "kex.h"
 
+#define KEX_COOKIE_LEN	16
+
 Buffer *
 kex_init(char *myproposal[PROPOSAL_MAX])
 {
-	char c = 0;
-	unsigned char cookie[16];
+	int first_kex_packet_follows = 0;
+	unsigned char cookie[KEX_COOKIE_LEN];
 	u_int32_t rand = 0;
 	int i;
 	Buffer *ki = xmalloc(sizeof(*ki));
-	for (i = 0; i < 16; i++) {
+	for (i = 0; i < KEX_COOKIE_LEN; i++) {
 		if (i % 4 == 0)
 			rand = arc4random();
 		cookie[i] = rand & 0xff;
@@ -67,11 +70,55 @@ kex_init(char *myproposal[PROPOSAL_MAX])
 	buffer_append(ki, (char *)cookie, sizeof cookie);
 	for (i = 0; i < PROPOSAL_MAX; i++)
 		buffer_put_cstring(ki, myproposal[i]);
-	buffer_append(ki, &c, 1); /* boolean   first_kex_packet_follows */
-	buffer_put_int(ki, 0);    /* uint32    0 (reserved for future extension) */
+	buffer_put_char(ki, first_kex_packet_follows);
+	buffer_put_int(ki, 0);				/* uint32 reserved */
 	return ki;
 }
 
+/* send kexinit, parse and save reply */
+void
+kex_exchange_kexinit(
+    Buffer *my_kexinit, Buffer *peer_kexint,
+    char *peer_proposal[PROPOSAL_MAX])
+{
+	int i;
+	char *ptr;
+	int plen;
+
+	debug("send KEXINIT");
+	packet_start(SSH2_MSG_KEXINIT);
+	packet_put_raw(buffer_ptr(my_kexinit), buffer_len(my_kexinit));	
+	packet_send();
+	packet_write_wait();
+	debug("done");
+
+	/*
+	 * read and save raw KEXINIT payload in buffer. this is used during
+	 * computation of the session_id and the session keys.
+	 */
+	debug("wait KEXINIT");
+	packet_read_expect(&plen, SSH2_MSG_KEXINIT);
+	ptr = packet_get_raw(&plen);
+	buffer_append(peer_kexint, ptr, plen);
+
+	/* parse packet and save algorithm proposal */
+	/* skip cookie */
+	for (i = 0; i < KEX_COOKIE_LEN; i++)
+		packet_get_char();
+	/* extract kex init proposal strings */
+	for (i = 0; i < PROPOSAL_MAX; i++) {
+		peer_proposal[i] = packet_get_string(NULL);
+		debug("got kexinit: %s", peer_proposal[i]);
+	}
+	/* first kex follow / reserved */
+	i = packet_get_char();
+	debug("first kex follow: %d ", i);
+	i = packet_get_int();
+	debug("reserved: %d ", i);
+	packet_done();
+	debug("done");
+}
+
 /* diffie-hellman-group1-sha1 */
 
 int
@@ -134,12 +181,6 @@ dh_new_group1()
 }
 
 void
-bignum_print(BIGNUM *b)
-{
-	BN_print_fp(stderr,b);
-}
-
-void
 dump_digest(unsigned char *digest, int len)
 {
 	int i;
@@ -246,10 +287,13 @@ char *
 get_match(char *client, char *server)
 {
 	char *sproposals[MAX_PROP];
-	char *p;
+	char *c, *s, *p, *ret;
 	int i, j, nproposals;
 
-	for ((p = strtok(server, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
+	c = xstrdup(client);
+	s = xstrdup(server);
+
+	for ((p = strtok(s, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
 		if (i < MAX_PROP)
 			sproposals[i] = p;
 		else
@@ -257,11 +301,18 @@ get_match(char *client, char *server)
 	}
 	nproposals = i;
 
-	for ((p = strtok(client, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
-		for (j = 0; j < nproposals; j++)
-			if (strcmp(p, sproposals[j]) == 0)
-				return xstrdup(p);
+	for ((p = strtok(c, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
+		for (j = 0; j < nproposals; j++) {
+			if (strcmp(p, sproposals[j]) == 0) {
+				ret = xstrdup(p);
+				xfree(c);
+				xfree(s);
+				return ret;
+			}
+		}
 	}
+	xfree(c);
+	xfree(s);
 	return NULL;
 }
 void
@@ -355,7 +406,6 @@ choose_hostkeyalg(Kex *k, char *client, char *server)
 Kex *
 kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server)
 {
-	int i;
 	int mode;
 	int ctos;				/* direction: if true client-to-server */
 	int need;
@@ -383,10 +433,6 @@ kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server
 	choose_kex(k, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
 	choose_hostkeyalg(k, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
 	    sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
-	for (i = 0; i < PROPOSAL_MAX; i++) {
-		xfree(cprop[i]);
-		xfree(sprop[i]);
-	}
 	need = 0;
 	for (mode = 0; mode < MODE_MAX; mode++) {
 	    if (need < k->enc[mode].key_len)
@@ -396,9 +442,7 @@ kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server
 	    if (need < k->mac[mode].key_len)
 		    need = k->mac[mode].key_len;
 	}
-	/* need runden? */
-#define WE_NEED 32
-	k->we_need = WE_NEED;
+	/* XXX need runden? */
 	k->we_need = need;
 	return k;
 }
diff --git a/usr.bin/ssh/kex.h b/usr.bin/ssh/kex.h
index 5395ebc3f08..7e5c67024bf 100644
--- a/usr.bin/ssh/kex.h
+++ b/usr.bin/ssh/kex.h
@@ -91,12 +91,17 @@ struct Kex {
 };
 
 Buffer	*kex_init(char *myproposal[PROPOSAL_MAX]);
-int	dh_pub_is_valid(DH *dh, BIGNUM *dh_pub);
-DH	*dh_new_group1();
-Kex 	*kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server);
+void
+kex_exchange_kexinit(
+    Buffer *my_kexinit, Buffer *peer_kexint,
+    char *peer_proposal[PROPOSAL_MAX]);
+Kex *
+kex_choose_conf(char *cprop[PROPOSAL_MAX],
+    char *sprop[PROPOSAL_MAX], int server);
 int	kex_derive_keys(Kex *k, unsigned char *hash, BIGNUM *shared_secret);
-void	bignum_print(BIGNUM *b);
 void	packet_set_kex(Kex *k);
+int	dh_pub_is_valid(DH *dh, BIGNUM *dh_pub);
+DH	*dh_new_group1();
 
 unsigned char *
 kex_hash(
diff --git a/usr.bin/ssh/myproposal.h b/usr.bin/ssh/myproposal.h
index 8b24179724f..9611d89517d 100644
--- a/usr.bin/ssh/myproposal.h
+++ b/usr.bin/ssh/myproposal.h
@@ -6,7 +6,7 @@
 #define	KEX_DEFAULT_LANG	""
 
 
-static const char *myproposal[PROPOSAL_MAX] = {
+static char *myproposal[PROPOSAL_MAX] = {
 	KEX_DEFAULT_KEX,
 	KEX_DEFAULT_PK_ALG,
 	KEX_DEFAULT_ENCRYPT,
diff --git a/usr.bin/ssh/sshconnect2.c b/usr.bin/ssh/sshconnect2.c
index 99ffb2c478d..0abcf89a0a0 100644
--- a/usr.bin/ssh/sshconnect2.c
+++ b/usr.bin/ssh/sshconnect2.c
@@ -28,7 +28,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshconnect2.c,v 1.10 2000/05/08 17:42:25 markus Exp $");
+RCSID("$OpenBSD: sshconnect2.c,v 1.11 2000/05/25 20:45:20 markus Exp $");
 
 #include <openssl/bn.h>
 #include <openssl/rsa.h>
@@ -68,16 +68,12 @@ unsigned char *session_id2 = NULL;
 int session_id2_len = 0;
 
 void
-ssh_kex2(char *host, struct sockaddr *hostaddr)
+ssh_kex_dh(Kex *kex, char *host, struct sockaddr *hostaddr,
+    Buffer *client_kexinit, Buffer *server_kexinit)
 {
-	Kex *kex;
-	char *cprop[PROPOSAL_MAX];
-	char *sprop[PROPOSAL_MAX];
-	Buffer *client_kexinit;
-	Buffer *server_kexinit;
-	int payload_len, dlen;
+	int i;
+	int plen, dlen;
 	unsigned int klen, kout;
-	char *ptr;
 	char *signature = NULL;
 	unsigned int slen;
 	char *server_host_key_blob = NULL;
@@ -86,72 +82,10 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 	DH *dh;
 	BIGNUM *dh_server_pub = 0;
 	BIGNUM *shared_secret = 0;
-	int i;
 	unsigned char *kbuf;
 	unsigned char *hash;
 
-/* KEXINIT */
-
-	debug("Sending KEX init.");
-	if (options.ciphers != NULL) {
-		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
-		myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
-	} else if (options.cipher == SSH_CIPHER_3DES) {
-		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
-		myproposal[PROPOSAL_ENC_ALGS_STOC] =
-		    cipher_name(SSH_CIPHER_3DES_CBC);
-	} else if (options.cipher == SSH_CIPHER_BLOWFISH) {
-		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
-		myproposal[PROPOSAL_ENC_ALGS_STOC] =
-		    cipher_name(SSH_CIPHER_BLOWFISH_CBC);
-	}
-	if (options.compression) {
-		myproposal[PROPOSAL_COMP_ALGS_CTOS] = "zlib";
-		myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib";
-	} else {
-		myproposal[PROPOSAL_COMP_ALGS_CTOS] = "none";
-		myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
-	}
-	for (i = 0; i < PROPOSAL_MAX; i++)
-		cprop[i] = xstrdup(myproposal[i]);
-
-	client_kexinit = kex_init(cprop);
-	packet_start(SSH2_MSG_KEXINIT);
-	packet_put_raw(buffer_ptr(client_kexinit), buffer_len(client_kexinit));	
-	packet_send();
-	packet_write_wait();
-
-	debug("done");
-
-	packet_read_expect(&payload_len, SSH2_MSG_KEXINIT);
-
-	/* save payload for session_id */
-	server_kexinit = xmalloc(sizeof(*server_kexinit));
-	buffer_init(server_kexinit);
-	ptr = packet_get_raw(&payload_len);
-	buffer_append(server_kexinit, ptr, payload_len);
-
-	/* skip cookie */
-	for (i = 0; i < 16; i++)
-		(void) packet_get_char();
-	/* kex init proposal strings */
-	for (i = 0; i < PROPOSAL_MAX; i++) {
-		sprop[i] = packet_get_string(NULL);
-		debug("got kexinit string: %s", sprop[i]);
-	}
-	i = (int) packet_get_char();
-	debug("first kex follow == %d", i);
-	i = packet_get_int();
-	debug("reserved == %d", i);
-	packet_done();
-
-	debug("done read kexinit");
-	kex = kex_choose_conf(cprop, sprop, 0);
-
-/* KEXDH */
-
 	debug("Sending SSH2_MSG_KEXDH_INIT.");
-
 	/* generate and send 'e', client DH public key */
 	dh = dh_new_group1();
 	packet_start(SSH2_MSG_KEXDH_INIT);
@@ -172,7 +106,7 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 
 	debug("Wait SSH2_MSG_KEXDH_REPLY.");
 
-	packet_read_expect(&payload_len, SSH2_MSG_KEXDH_REPLY);
+	packet_read_expect(&plen, SSH2_MSG_KEXDH_REPLY);
 
 	debug("Got SSH2_MSG_KEXDH_REPLY.");
 
@@ -233,10 +167,7 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 	    shared_secret
 	);
 	xfree(server_host_key_blob);
-	buffer_free(client_kexinit);
-	buffer_free(server_kexinit);
-	xfree(client_kexinit);
-	xfree(server_kexinit);
+	DH_free(dh);
 #ifdef DEBUG_KEXDH
 	fprintf(stderr, "hash == ");
 	for (i = 0; i< 20; i++)
@@ -250,16 +181,61 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 	kex_derive_keys(kex, hash, shared_secret);
 	packet_set_kex(kex);
 
-	/* have keys, free DH */
-	DH_free(dh);
-
 	/* save session id */
 	session_id2_len = 20;
 	session_id2 = xmalloc(session_id2_len);
 	memcpy(session_id2, hash, session_id2_len);
+}
+
+void
+ssh_kex2(char *host, struct sockaddr *hostaddr)
+{
+	int i, plen;
+	Kex *kex;
+	Buffer *client_kexinit, *server_kexinit;
+	char *sprop[PROPOSAL_MAX];
+
+	if (options.ciphers != NULL) {
+		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+		myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
+	} else if (options.cipher == SSH_CIPHER_3DES) {
+		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+		myproposal[PROPOSAL_ENC_ALGS_STOC] =
+		    (char *) cipher_name(SSH_CIPHER_3DES_CBC);
+	} else if (options.cipher == SSH_CIPHER_BLOWFISH) {
+		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+		myproposal[PROPOSAL_ENC_ALGS_STOC] =
+		    (char *) cipher_name(SSH_CIPHER_BLOWFISH_CBC);
+	}
+	if (options.compression) {
+		myproposal[PROPOSAL_COMP_ALGS_CTOS] = "zlib";
+		myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib";
+	} else {
+		myproposal[PROPOSAL_COMP_ALGS_CTOS] = "none";
+		myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
+	}
+
+	/* buffers with raw kexinit messages */
+	server_kexinit = xmalloc(sizeof(*server_kexinit));
+	buffer_init(server_kexinit);
+	client_kexinit = kex_init(myproposal);
+
+	/* algorithm negotiation */
+	kex_exchange_kexinit(client_kexinit, server_kexinit, sprop);
+	kex = kex_choose_conf(myproposal, sprop, 0);
+	for (i = 0; i < PROPOSAL_MAX; i++)
+		xfree(sprop[i]);
+
+	/* server authentication and session key agreement */
+	ssh_kex_dh(kex, host, hostaddr, client_kexinit, server_kexinit);
+
+	buffer_free(client_kexinit);
+	buffer_free(server_kexinit);
+	xfree(client_kexinit);
+	xfree(server_kexinit);
 
 	debug("Wait SSH2_MSG_NEWKEYS.");
-	packet_read_expect(&payload_len, SSH2_MSG_NEWKEYS);
+	packet_read_expect(&plen, SSH2_MSG_NEWKEYS);
 	packet_done();
 	debug("GOT SSH2_MSG_NEWKEYS.");
 
@@ -278,6 +254,7 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 #endif
 	debug("done: KEX2.");
 }
+
 /*
  * Authenticate user
  */
diff --git a/usr.bin/ssh/sshd.c b/usr.bin/ssh/sshd.c
index d5283ce72f1..4a1a47fc968 100644
--- a/usr.bin/ssh/sshd.c
+++ b/usr.bin/ssh/sshd.c
@@ -14,7 +14,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.117 2000/05/18 13:27:36 djm Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.118 2000/05/25 20:45:20 markus Exp $");
 
 #include "xmalloc.h"
 #include "rsa.h"
@@ -1149,7 +1149,6 @@ do_ssh2_kex()
 	int payload_len, dlen;
 	int slen;
 	unsigned int klen, kout;
-	char *ptr;
 	unsigned char *signature = NULL;
 	unsigned char *server_host_key_blob = NULL;
 	unsigned int sbloblen;
@@ -1161,7 +1160,6 @@ do_ssh2_kex()
 	unsigned char *hash;
 	Kex *kex;
 	char *cprop[PROPOSAL_MAX];
-	char *sprop[PROPOSAL_MAX];
 
 /* KEXINIT */
 
@@ -1169,46 +1167,15 @@ do_ssh2_kex()
 		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
 		myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
 	}
-
-	debug("Sending KEX init.");
-
-	for (i = 0; i < PROPOSAL_MAX; i++)
-		sprop[i] = xstrdup(myproposal[i]);
-	server_kexinit = kex_init(sprop);
-	packet_start(SSH2_MSG_KEXINIT);
-	packet_put_raw(buffer_ptr(server_kexinit), buffer_len(server_kexinit));	
-	packet_send();
-	packet_write_wait();
-
-	debug("done");
-
-	packet_read_expect(&payload_len, SSH2_MSG_KEXINIT);
-
-	/*
-	 * save raw KEXINIT payload in buffer. this is used during
-	 * computation of the session_id and the session keys.
-	 */
+	server_kexinit = kex_init(myproposal);
 	client_kexinit = xmalloc(sizeof(*client_kexinit));
 	buffer_init(client_kexinit);
-	ptr = packet_get_raw(&payload_len);
-	buffer_append(client_kexinit, ptr, payload_len);
 
-	/* skip cookie */
-	for (i = 0; i < 16; i++)
-		(void) packet_get_char();
-	/* save kex init proposal strings */
-	for (i = 0; i < PROPOSAL_MAX; i++) {
-		cprop[i] = packet_get_string(NULL);
-		debug("got kexinit string: %s", cprop[i]);
-	}
-
-	i = (int) packet_get_char();
-	debug("first kex follow == %d", i);
-	i = packet_get_int();
-	debug("reserved == %d", i);
-
-	debug("done read kexinit");
-	kex = kex_choose_conf(cprop, sprop, 1);
+	/* algorithm negotiation */
+	kex_exchange_kexinit(server_kexinit, client_kexinit, cprop);
+	kex = kex_choose_conf(cprop, myproposal, 1);
+	for (i = 0; i < PROPOSAL_MAX; i++)
+		xfree(cprop[i]);
 
 /* KEXDH */