- (djm) Big OpenBSD sync:

   - markus@cvs.openbsd.org  2000/09/30 10:27:44
     [log.c]
     allow loglevel debug
   - markus@cvs.openbsd.org  2000/10/03 11:59:57
     [packet.c]
     hmac->mac
   - markus@cvs.openbsd.org  2000/10/03 12:03:03
     [auth-krb4.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c]
     move fake-auth from auth1.c to individual auth methods, disables s/key in
     debug-msg
   - markus@cvs.openbsd.org  2000/10/03 12:16:48
     ssh.c
     do not resolve canonname, i have no idea why this was added oin ossh
   - markus@cvs.openbsd.org  2000/10/09 15:30:44
     ssh-keygen.1 ssh-keygen.c
     -X now reads private ssh.com DSA keys, too.
   - markus@cvs.openbsd.org  2000/10/09 15:32:34
     auth-options.c
     clear options on every call.
   - markus@cvs.openbsd.org  2000/10/09 15:51:00
     authfd.c authfd.h
     interop with ssh-agent2, from <res@shore.net>
   - markus@cvs.openbsd.org  2000/10/10 14:20:45
     compat.c
     use rexexp for version string matching
   - provos@cvs.openbsd.org  2000/10/10 22:02:18
     [kex.c kex.h myproposal.h ssh.h ssh2.h sshconnect2.c sshd.c dh.c dh.h]
     First rough implementation of the diffie-hellman group exchange.  The
     client can ask the server for bigger groups to perform the diffie-hellman
     in, thus increasing the attack complexity when using ciphers with longer
     keys.  University of Windsor provided network, T the company.
   - markus@cvs.openbsd.org  2000/10/11 13:59:52
     [auth-rsa.c auth2.c]
     clear auth options unless auth sucessfull
   - markus@cvs.openbsd.org  2000/10/11 14:00:27
     [auth-options.h]
     clear auth options unless auth sucessfull
   - markus@cvs.openbsd.org  2000/10/11 14:03:27
     [scp.1 scp.c]
     support 'scp -o' with help from mouring@pconline.com
   - markus@cvs.openbsd.org  2000/10/11 14:11:35
     [dh.c]
     Wall
   - markus@cvs.openbsd.org  2000/10/11 14:14:40
     [auth.h auth2.c readconf.c readconf.h readpass.c servconf.c servconf.h]
     [ssh.h sshconnect2.c sshd_config auth2-skey.c cli.c cli.h]
     add support for s/key (kbd-interactive) to ssh2, based on work by
     mkiernan@avantgo.com and me
   - markus@cvs.openbsd.org  2000/10/11 14:27:24
     [auth.c auth1.c auth2.c authfile.c cipher.c cipher.h kex.c kex.h]
     [myproposal.h packet.c readconf.c session.c ssh.c ssh.h sshconnect1.c]
     [sshconnect2.c sshd.c]
     new cipher framework
   - markus@cvs.openbsd.org  2000/10/11 14:45:21
     [cipher.c]
     remove DES
   - markus@cvs.openbsd.org  2000/10/12 03:59:20
     [cipher.c cipher.h sshconnect1.c sshconnect2.c sshd.c]
     enable DES in SSH-1 clients only
   - markus@cvs.openbsd.org  2000/10/12 08:21:13
     [kex.h packet.c]
     remove unused
   - markus@cvs.openbsd.org  2000/10/13 12:34:46
     [sshd.c]
     Kludge for F-Secure Macintosh < 1.0.2; appro@fy.chalmers.se
   - markus@cvs.openbsd.org  2000/10/13 12:59:15
     [cipher.c cipher.h myproposal.h  rijndael.c rijndael.h]
     rijndael/aes support
   - markus@cvs.openbsd.org  2000/10/13 13:10:54
     [sshd.8]
     more info about -V
   - markus@cvs.openbsd.org  2000/10/13 13:12:02
     [myproposal.h]
     prefer no compression

1 files changed, 115 insertions, 54 deletions

diff --git a/kex.c b/kex.c
index 8a83db47..68b9e522 100644
--- a/kex.c
+++ b/kex.c
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: kex.c,v 1.10 2000/09/07 20:27:51 deraadt Exp $");
+RCSID("$OpenBSD: kex.c,v 1.12 2000/10/11 20:27:23 markus Exp $");
 
 #include "ssh.h"
 #include "ssh2.h"
@@ -31,7 +31,6 @@ RCSID("$OpenBSD: kex.c,v 1.10 2000/09/07 20:27:51 deraadt Exp $");
 #include "buffer.h"
 #include "bufaux.h"
 #include "packet.h"
-#include "cipher.h"
 #include "compat.h"
 
 #include <openssl/bn.h>
@@ -123,11 +122,6 @@ dh_pub_is_valid(DH *dh, BIGNUM *dh_pub)
 	int n = BN_num_bits(dh_pub);
 	int bits_set = 0;
 
-	/* we only accept g==2 */
-	if (!BN_is_word(dh->g, 2)) {
-		log("invalid DH base != 2");
-		return 0;
-	}
 	if (dh_pub->neg) {
 		log("invalid public DH value: negativ");
 		return 0;
@@ -145,27 +139,10 @@ dh_pub_is_valid(DH *dh, BIGNUM *dh_pub)
 }
 
 DH *
-dh_new_group1()
+dh_gen_key(DH *dh)
 {
-	static char *group1 =
-	    "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
-	    "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
-	    "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
-	    "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
-	    "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE65381"
-	    "FFFFFFFF" "FFFFFFFF";
-	DH *dh;
-	int ret, tries = 0;
-	dh = DH_new();
-	if(dh == NULL)
-		fatal("DH_new");
-	ret = BN_hex2bn(&dh->p, group1);
-	if(ret<0)
-		fatal("BN_hex2bn");
-	dh->g = BN_new();
-	if(dh->g == NULL)
-		fatal("DH_new g");
-	BN_set_word(dh->g, 2);
+	int tries = 0;
+
 	do {
 		if (DH_generate_key(dh) == 0)
 			fatal("DH_generate_key");
@@ -175,6 +152,52 @@ dh_new_group1()
 	return dh;
 }
 
+DH *
+dh_new_group_asc(const char *gen, const char *modulus)
+{
+	DH *dh;
+	int ret;
+
+	dh = DH_new();
+	if (dh == NULL)
+		fatal("DH_new");
+
+	if ((ret = BN_hex2bn(&dh->p, modulus)) < 0)
+		fatal("BN_hex2bn p");
+	if ((ret = BN_hex2bn(&dh->g, gen)) < 0)
+		fatal("BN_hex2bn g");
+
+	return (dh_gen_key(dh));
+}
+
+DH *
+dh_new_group(BIGNUM *gen, BIGNUM *modulus)
+{
+	DH *dh;
+
+	dh = DH_new();
+	if (dh == NULL)
+		fatal("DH_new");
+	dh->p = modulus;
+	dh->g = gen;
+
+	return (dh_gen_key(dh));
+}
+
+DH *
+dh_new_group1()
+{
+	static char *gen = "2", *group1 =
+	    "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
+	    "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
+	    "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
+	    "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
+	    "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE65381"
+	    "FFFFFFFF" "FFFFFFFF";
+
+	return (dh_new_group_asc(gen, group1));
+}
+
 void
 dump_digest(unsigned char *digest, int len)
 {
@@ -237,6 +260,59 @@ kex_hash(
 }
 
 unsigned char *
+kex_hash_gex(
+    char *client_version_string,
+    char *server_version_string,
+    char *ckexinit, int ckexinitlen,
+    char *skexinit, int skexinitlen,
+    char *serverhostkeyblob, int sbloblen,
+    int minbits, BIGNUM *prime, BIGNUM *gen,
+    BIGNUM *client_dh_pub,
+    BIGNUM *server_dh_pub,
+    BIGNUM *shared_secret)
+{
+	Buffer b;
+	static unsigned char digest[EVP_MAX_MD_SIZE];
+	EVP_MD *evp_md = EVP_sha1();
+	EVP_MD_CTX md;
+
+	buffer_init(&b);
+	buffer_put_string(&b, client_version_string, strlen(client_version_string));
+	buffer_put_string(&b, server_version_string, strlen(server_version_string));
+
+	/* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
+	buffer_put_int(&b, ckexinitlen+1);
+	buffer_put_char(&b, SSH2_MSG_KEXINIT);
+	buffer_append(&b, ckexinit, ckexinitlen);
+	buffer_put_int(&b, skexinitlen+1);
+	buffer_put_char(&b, SSH2_MSG_KEXINIT);
+	buffer_append(&b, skexinit, skexinitlen);
+
+	buffer_put_string(&b, serverhostkeyblob, sbloblen);
+	buffer_put_int(&b, minbits);
+	buffer_put_bignum2(&b, prime);
+	buffer_put_bignum2(&b, gen);
+	buffer_put_bignum2(&b, client_dh_pub);
+	buffer_put_bignum2(&b, server_dh_pub);
+	buffer_put_bignum2(&b, shared_secret);
+	
+#ifdef DEBUG_KEX
+	buffer_dump(&b);
+#endif
+
+	EVP_DigestInit(&md, evp_md);
+	EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
+	EVP_DigestFinal(&md, digest, NULL);
+
+	buffer_free(&b);
+
+#ifdef DEBUG_KEX
+	dump_digest(digest, evp_md->md_size);
+#endif
+	return digest;
+}
+
+unsigned char *
 derive_key(int id, int need, char unsigned *hash, BIGNUM *shared_secret)
 {
 	Buffer b;
@@ -318,28 +394,9 @@ choose_enc(Enc *enc, char *client, char *server)
 	char *name = get_match(client, server);
 	if (name == NULL)
 		fatal("no matching cipher found: client %s server %s", client, server);
-	enc->type = cipher_number(name);
-
-	switch (enc->type) {
-	case SSH_CIPHER_3DES_CBC:
-		enc->key_len = 24;
-		enc->iv_len = 8;
-		enc->block_size = 8;
-		break;
-	case SSH_CIPHER_BLOWFISH_CBC:
-	case SSH_CIPHER_CAST128_CBC:
-		enc->key_len = 16;
-		enc->iv_len = 8;
-		enc->block_size = 8;
-		break;
-	case SSH_CIPHER_ARCFOUR:
-		enc->key_len = 16;
-		enc->iv_len = 0;
-		enc->block_size = 8;
-		break;
-	default:
-		fatal("unsupported cipher %s", name);
-	}
+	enc->cipher = cipher_by_name(name);
+	if (enc->cipher == NULL)
+		fatal("matching cipher is not supported: %s", name);
 	enc->name = name;
 	enc->enabled = 0;
 	enc->iv = NULL;
@@ -387,7 +444,11 @@ choose_kex(Kex *k, char *client, char *server)
 	k->name = get_match(client, server);
 	if (k->name == NULL)
 		fatal("no kex alg");
-	if (strcmp(k->name, KEX_DH1) != 0)
+	if (strcmp(k->name, KEX_DH1) == 0) {
+		k->kex_type = DH_GRP1_SHA1;
+	} else if (strcmp(k->name, KEX_DHGEX) == 0) {
+		k->kex_type = DH_GEX_SHA1;
+	} else
 		fatal("bad kex alg %s", k->name);
 }
 void
@@ -432,10 +493,10 @@ kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server
 	    sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
 	need = 0;
 	for (mode = 0; mode < MODE_MAX; mode++) {
-	    if (need < k->enc[mode].key_len)
-		    need = k->enc[mode].key_len;
-	    if (need < k->enc[mode].iv_len)
-		    need = k->enc[mode].iv_len;
+	    if (need < k->enc[mode].cipher->key_len)
+		    need = k->enc[mode].cipher->key_len;
+	    if (need < k->enc[mode].cipher->block_size)
+		    need = k->enc[mode].cipher->block_size;
 	    if (need < k->mac[mode].key_len)
 		    need = k->mac[mode].key_len;
 	}