- markus@cvs.openbsd.org 2001/04/03 23:32:12
[kex.c kex.h packet.c sshconnect2.c sshd.c]
undo parts of recent my changes: main part of keyexchange does not
need dispatch-callbacks, since application data is delayed until
the keyexchange completes (if i understand the drafts correctly).
add some infrastructure for re-keying.
diff --git a/kex.c b/kex.c
index a0a5b46..3b42d32 100644
--- a/kex.c
+++ b/kex.c
@@ -23,7 +23,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: kex.c,v 1.26 2001/04/03 19:53:29 markus Exp $");
+RCSID("$OpenBSD: kex.c,v 1.27 2001/04/03 23:32:11 markus Exp $");
#include <openssl/crypto.h>
@@ -131,7 +131,7 @@
for (i = 30; i <= 49; i++)
dispatch_set(i, &kex_protocol_error);
buffer_clear(&kex->peer);
- buffer_clear(&kex->my);
+ /* buffer_clear(&kex->my); */
kex->flags &= ~KEX_INIT_SENT;
}
@@ -152,7 +152,6 @@
int dlen;
Kex *kex = (Kex *)ctxt;
- dispatch_set(SSH2_MSG_KEXINIT, &kex_protocol_error);
debug("SSH2_MSG_KEXINIT received");
ptr = packet_get_raw(&dlen);
@@ -274,18 +273,20 @@
}
void
-kex_choose_conf(Kex *k)
+kex_choose_conf(Kex *kex)
{
+ Newkeys *newkeys;
char **my, **peer;
char **cprop, **sprop;
+ int nenc, nmac, ncomp;
int mode;
int ctos; /* direction: if true client-to-server */
int need;
- my = kex_buf2prop(&k->my);
- peer = kex_buf2prop(&k->peer);
+ my = kex_buf2prop(&kex->my);
+ peer = kex_buf2prop(&kex->peer);
- if (k->server) {
+ if (kex->server) {
cprop=peer;
sprop=my;
} else {
@@ -294,42 +295,44 @@
}
for (mode = 0; mode < MODE_MAX; mode++) {
- int nenc, nmac, ncomp;
- ctos = (!k->server && mode == MODE_OUT) || (k->server && mode == MODE_IN);
+ newkeys = xmalloc(sizeof(*newkeys));
+ memset(newkeys, 0, sizeof(*newkeys));
+ kex->keys[mode] = newkeys;
+ ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN);
nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC;
nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC;
ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
- choose_enc (&k->enc [mode], cprop[nenc], sprop[nenc]);
- choose_mac (&k->mac [mode], cprop[nmac], sprop[nmac]);
- choose_comp(&k->comp[mode], cprop[ncomp], sprop[ncomp]);
+ choose_enc (&newkeys->enc, cprop[nenc], sprop[nenc]);
+ choose_mac (&newkeys->mac, cprop[nmac], sprop[nmac]);
+ choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]);
debug("kex: %s %s %s %s",
ctos ? "client->server" : "server->client",
- k->enc[mode].name,
- k->mac[mode].name,
- k->comp[mode].name);
+ newkeys->enc.name,
+ newkeys->mac.name,
+ newkeys->comp.name);
}
- choose_kex(k, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
- choose_hostkeyalg(k, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
+ choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
+ choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
need = 0;
for (mode = 0; mode < MODE_MAX; mode++) {
- 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;
+ newkeys = kex->keys[mode];
+ if (need < newkeys->enc.cipher->key_len)
+ need = newkeys->enc.cipher->key_len;
+ if (need < newkeys->enc.cipher->block_size)
+ need = newkeys->enc.cipher->block_size;
+ if (need < newkeys->mac.key_len)
+ need = newkeys->mac.key_len;
}
/* XXX need runden? */
- k->we_need = need;
+ kex->we_need = need;
kex_prop_free(my);
kex_prop_free(peer);
-
}
u_char *
-derive_key(int id, int need, u_char *hash, BIGNUM *shared_secret)
+derive_key(Kex *kex, int id, int need, u_char *hash, BIGNUM *shared_secret)
{
Buffer b;
EVP_MD *evp_md = EVP_sha1();
@@ -346,7 +349,7 @@
EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); /* shared_secret K */
EVP_DigestUpdate(&md, hash, mdsz); /* transport-06 */
EVP_DigestUpdate(&md, &c, 1); /* key id */
- EVP_DigestUpdate(&md, hash, mdsz); /* session id */
+ EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len);
EVP_DigestFinal(&md, digest, NULL);
/* expand */
@@ -365,26 +368,36 @@
return digest;
}
+Newkeys *x_newkeys[MODE_MAX];
+
#define NKEYS 6
void
-kex_derive_keys(Kex *k, u_char *hash, BIGNUM *shared_secret)
+kex_derive_keys(Kex *kex, u_char *hash, BIGNUM *shared_secret)
{
- int i;
- int mode;
- int ctos;
+ Newkeys *newkeys;
u_char *keys[NKEYS];
+ int i, mode, ctos;
for (i = 0; i < NKEYS; i++)
- keys[i] = derive_key('A'+i, k->we_need, hash, shared_secret);
+ keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, shared_secret);
+ debug("kex_derive_keys");
for (mode = 0; mode < MODE_MAX; mode++) {
- ctos = (!k->server && mode == MODE_OUT) || (k->server && mode == MODE_IN);
- k->enc[mode].iv = keys[ctos ? 0 : 1];
- k->enc[mode].key = keys[ctos ? 2 : 3];
- k->mac[mode].key = keys[ctos ? 4 : 5];
+ newkeys = kex->keys[mode];
+ ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN);
+ newkeys->enc.iv = keys[ctos ? 0 : 1];
+ newkeys->enc.key = keys[ctos ? 2 : 3];
+ newkeys->mac.key = keys[ctos ? 4 : 5];
+ x_newkeys[mode] = newkeys;
}
}
+Newkeys *
+kex_get_newkeys(int mode)
+{
+ return x_newkeys[mode];
+}
+
#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
void
dump_digest(char *msg, u_char *digest, int len)