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Handle differing c2s and s2c algorithms properly

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--HG--
extra : convert_revision : 5a8d0e105df84e50bc3e9d80486d6986634ff900
This commit is contained in:
Matt Johnston 2004-07-29 15:43:26 +00:00
parent e1491b8ec6
commit bf785cbcec
1 changed files with 50 additions and 23 deletions
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73
common-kex.c
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@ -411,7 +411,6 @@ void recv_msg_kexinit() {
if (IS_DROPBEAR_CLIENT) {
#ifdef DROPBEAR_CLIENT
/* read the peer's choice of algos */
read_kex_algos();
@ -433,10 +432,8 @@ void recv_msg_kexinit() {
buf_getptr(ses.payload, ses.payload->len),
ses.payload->len);
#endif
} else {
/* SERVER */
#ifdef DROPBEAR_SERVER
/* read the peer's choice of algos */
read_kex_algos();
@ -457,7 +454,6 @@ void recv_msg_kexinit() {
buf_getptr(ses.transkexinit, ses.transkexinit->len),
ses.transkexinit->len);
ses.requirenext = SSH_MSG_KEXDH_INIT;
#endif
}
buf_free(ses.transkexinit);
@ -596,7 +592,17 @@ void kexdh_comb_key(mp_int *dh_pub_us, mp_int *dh_priv, mp_int *dh_pub_them,
* algos for the client or server. */
static void read_kex_algos() {
algo_type * algo;
/* for asymmetry */
algo_type * c2s_hash_algo = NULL;
algo_type * s2c_hash_algo = NULL;
algo_type * c2s_cipher_algo = NULL;
algo_type * s2c_cipher_algo = NULL;
algo_type * c2s_comp_algo = NULL;
algo_type * s2c_comp_algo = NULL;
/* the generic one */
algo_type * algo = NULL;
/* which algo couldn't match */
char * erralgo = NULL;
int goodguess = 0;
@ -628,58 +634,46 @@ static void read_kex_algos() {
ses.newkeys->algo_hostkey = algo->val;
/* encryption_algorithms_client_to_server */
algo = ses.buf_match_algo(ses.payload, sshciphers, &goodguess);
c2s_cipher_algo = ses.buf_match_algo(ses.payload, sshciphers, &goodguess);
if (algo == NULL) {
erralgo = "enc c->s";
goto error;
}
ses.newkeys->recv_algo_crypt = (struct dropbear_cipher*)algo->data;
TRACE(("enc algo recv %s", algo->name));
/* encryption_algorithms_server_to_client */
algo = ses.buf_match_algo(ses.payload, sshciphers, &goodguess);
s2c_cipher_algo = ses.buf_match_algo(ses.payload, sshciphers, &goodguess);
if (algo == NULL) {
erralgo = "enc s->c";
goto error;
}
ses.newkeys->trans_algo_crypt = (struct dropbear_cipher*)algo->data;
TRACE(("enc algo trans %s", algo->name));
/* mac_algorithms_client_to_server */
algo = ses.buf_match_algo(ses.payload, sshhashes, &goodguess);
c2s_hash_algo = ses.buf_match_algo(ses.payload, sshhashes, &goodguess);
if (algo == NULL) {
erralgo = "mac c->s";
goto error;
}
ses.newkeys->recv_algo_mac = (struct dropbear_hash*)algo->data;
TRACE(("mac algo recv %s", algo->name));
/* mac_algorithms_server_to_client */
algo = ses.buf_match_algo(ses.payload, sshhashes, &goodguess);
s2c_hash_algo = ses.buf_match_algo(ses.payload, sshhashes, &goodguess);
if (algo == NULL) {
erralgo = "mac s->c";
goto error;
}
ses.newkeys->trans_algo_mac = (struct dropbear_hash*)algo->data;
TRACE(("mac algo trans %s", algo->name));
/* compression_algorithms_client_to_server */
algo = ses.buf_match_algo(ses.payload, sshcompress, &goodguess);
c2s_comp_algo = ses.buf_match_algo(ses.payload, sshcompress, &goodguess);
if (algo == NULL) {
erralgo = "comp c->s";
goto error;
}
ses.newkeys->recv_algo_comp = algo->val;
TRACE(("comp algo recv %s", algo->name));
/* compression_algorithms_server_to_client */
algo = ses.buf_match_algo(ses.payload, sshcompress, &goodguess);
s2c_comp_algo = ses.buf_match_algo(ses.payload, sshcompress, &goodguess);
if (algo == NULL) {
erralgo = "comp s->c";
goto error;
}
ses.newkeys->trans_algo_comp = algo->val;
TRACE(("comp algo trans %s", algo->name));
/* languages_client_to_server */
buf_eatstring(ses.payload);
@ -696,6 +690,39 @@ static void read_kex_algos() {
}
}
/* Handle the asymmetry */
if (IS_DROPBEAR_CLIENT) {
ses.newkeys->recv_algo_crypt =
(struct dropbear_cipher*)s2c_cipher_algo->data;
ses.newkeys->trans_algo_crypt =
(struct dropbear_cipher*)c2s_cipher_algo->data;
ses.newkeys->recv_algo_mac =
(struct dropbear_hash*)s2c_hash_algo->data;
ses.newkeys->trans_algo_mac =
(struct dropbear_hash*)c2s_hash_algo->data;
ses.newkeys->recv_algo_comp = s2c_comp_algo->val;
ses.newkeys->trans_algo_comp = c2s_comp_algo->val;
} else {
/* SERVER */
ses.newkeys->recv_algo_crypt =
(struct dropbear_cipher*)c2s_cipher_algo->data;
ses.newkeys->trans_algo_crypt =
(struct dropbear_cipher*)s2c_cipher_algo->data;
ses.newkeys->recv_algo_mac =
(struct dropbear_hash*)c2s_hash_algo->data;
ses.newkeys->trans_algo_mac =
(struct dropbear_hash*)s2c_hash_algo->data;
ses.newkeys->recv_algo_comp = c2s_comp_algo->val;
ses.newkeys->trans_algo_comp = s2c_comp_algo->val;
}
TRACE(("enc algo recv %s", algo->name));
TRACE(("enc algo trans %s", algo->name));
TRACE(("mac algo recv %s", algo->name));
TRACE(("mac algo trans %s", algo->name));
TRACE(("comp algo recv %s", algo->name));
TRACE(("comp algo trans %s", algo->name));
/* reserved for future extensions */
buf_getint(ses.payload);
return;