]> andersk Git - openssh.git/blobdiff - kex.c
- (djm) Big OpenBSD sync:
[openssh.git] / kex.c
diff --git a/kex.c b/kex.c
index 8a83db47e8067761e8ed37dfb34aeff65efecfd6..68b9e522e73d96bfdc9b8c502ccb700ef7427888 100644 (file)
--- 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)
 {
@@ -236,6 +259,59 @@ kex_hash(
        return digest;
 }
 
+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)
 {
@@ -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;
        }
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