- 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/packet.c b/packet.c
index 1a634cf..a4a0b05 100644
--- a/packet.c
+++ b/packet.c
@@ -37,7 +37,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: packet.c,v 1.56 2001/03/03 21:41:07 millert Exp $");
+RCSID("$OpenBSD: packet.c,v 1.57 2001/04/03 23:32:12 markus Exp $");
#include "xmalloc.h"
#include "buffer.h"
@@ -121,21 +121,9 @@
int use_ssh2_packet_format = 0;
/* Session key information for Encryption and MAC */
-Kex *kex = NULL;
+Newkeys *newkeys[MODE_MAX];
void
-packet_set_kex(Kex *k)
-{
- if( k->mac[MODE_IN ].key == NULL ||
- k->enc[MODE_IN ].key == NULL ||
- k->enc[MODE_IN ].iv == NULL ||
- k->mac[MODE_OUT].key == NULL ||
- k->enc[MODE_OUT].key == NULL ||
- k->enc[MODE_OUT].iv == NULL)
- fatal("bad KEX");
- kex = k;
-}
-void
clear_enc_keys(Enc *enc, int len)
{
memset(enc->iv, 0, len);
@@ -150,6 +138,7 @@
{
DBG(debug("use_ssh2_packet_format"));
use_ssh2_packet_format = 1;
+ newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL;
}
/*
@@ -522,6 +511,41 @@
*/
}
+void
+set_newkeys(int mode)
+{
+ Enc *enc;
+ Mac *mac;
+ Comp *comp;
+ CipherContext *cc;
+
+ debug("newkeys: mode %d", mode);
+
+ cc = (mode == MODE_OUT) ? &send_context : &receive_context;
+ if (newkeys[mode] != NULL) {
+ debug("newkeys: rekeying");
+ memset(cc, 0, sizeof(*cc));
+ // free old keys, reset compression cipher-contexts;
+ }
+ newkeys[mode] = kex_get_newkeys(mode);
+ if (newkeys[mode] == NULL)
+ fatal("newkeys: no keys for mode %d", mode);
+ enc = &newkeys[mode]->enc;
+ mac = &newkeys[mode]->mac;
+ comp = &newkeys[mode]->comp;
+ if (mac->md != NULL)
+ mac->enabled = 1;
+ DBG(debug("cipher_init_context: %d", mode));
+ cipher_init(cc, enc->cipher, enc->key, enc->cipher->key_len,
+ enc->iv, enc->cipher->block_size);
+ clear_enc_keys(enc, enc->cipher->key_len);
+ if (comp->type != 0 && comp->enabled == 0) {
+ comp->enabled = 1;
+ if (! packet_compression)
+ packet_start_compression(6);
+ }
+}
+
/*
* Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
*/
@@ -540,10 +564,10 @@
Comp *comp = NULL;
int block_size;
- if (kex != NULL) {
- enc = &kex->enc[MODE_OUT];
- mac = &kex->mac[MODE_OUT];
- comp = &kex->comp[MODE_OUT];
+ if (newkeys[MODE_OUT] != NULL) {
+ enc = &newkeys[MODE_OUT]->enc;
+ mac = &newkeys[MODE_OUT]->mac;
+ comp = &newkeys[MODE_OUT]->comp;
}
block_size = enc ? enc->cipher->block_size : 8;
@@ -622,22 +646,8 @@
log("outgoing seqnr wraps around");
buffer_clear(&outgoing_packet);
- if (type == SSH2_MSG_NEWKEYS) {
- if (kex==NULL || mac==NULL || enc==NULL || comp==NULL)
- fatal("packet_send2: no KEX");
- if (mac->md != NULL)
- mac->enabled = 1;
- DBG(debug("cipher_init send_context"));
- cipher_init(&send_context, enc->cipher,
- enc->key, enc->cipher->key_len,
- enc->iv, enc->cipher->block_size);
- clear_enc_keys(enc, kex->we_need);
- if (comp->type != 0 && comp->enabled == 0) {
- comp->enabled = 1;
- if (! packet_compression)
- packet_start_compression(6);
- }
- }
+ if (type == SSH2_MSG_NEWKEYS)
+ set_newkeys(MODE_OUT);
}
void
@@ -833,10 +843,10 @@
Mac *mac = NULL;
Comp *comp = NULL;
- if (kex != NULL) {
- enc = &kex->enc[MODE_IN];
- mac = &kex->mac[MODE_IN];
- comp = &kex->comp[MODE_IN];
+ if (newkeys[MODE_IN] != NULL) {
+ enc = &newkeys[MODE_IN]->enc;
+ mac = &newkeys[MODE_IN]->mac;
+ comp = &newkeys[MODE_IN]->comp;
}
maclen = mac && mac->enabled ? mac->mac_len : 0;
block_size = enc ? enc->cipher->block_size : 8;
@@ -930,22 +940,8 @@
/* extract packet type */
type = (u_char)buf[0];
- if (type == SSH2_MSG_NEWKEYS) {
- if (kex==NULL || mac==NULL || enc==NULL || comp==NULL)
- fatal("packet_read_poll2: no KEX");
- if (mac->md != NULL)
- mac->enabled = 1;
- DBG(debug("cipher_init receive_context"));
- cipher_init(&receive_context, enc->cipher,
- enc->key, enc->cipher->key_len,
- enc->iv, enc->cipher->block_size);
- clear_enc_keys(enc, kex->we_need);
- if (comp->type != 0 && comp->enabled == 0) {
- comp->enabled = 1;
- if (! packet_compression)
- packet_start_compression(6);
- }
- }
+ if (type == SSH2_MSG_NEWKEYS)
+ set_newkeys(MODE_IN);
#ifdef PACKET_DEBUG
fprintf(stderr, "read/plain[%d]:\r\n", type);
@@ -1339,8 +1335,8 @@
have = buffer_len(&outgoing_packet);
debug2("packet_inject_ignore: current %d", have);
- if (kex != NULL)
- enc = &kex->enc[MODE_OUT];
+ if (newkeys[MODE_OUT] != NULL)
+ enc = &newkeys[MODE_OUT]->enc;
blocksize = enc ? enc->cipher->block_size : 8;
padlen = blocksize - (have % blocksize);
if (padlen < 4)