+/* $OpenBSD: kex.c,v 1.76 2006/08/03 03:34:42 deraadt Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
*
*/
#include "includes.h"
-RCSID("$OpenBSD: kex.c,v 1.64 2005/07/25 11:59:39 markus Exp $");
+
+#include <sys/param.h>
+
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
#include <openssl/crypto.h>
-#include "ssh2.h"
#include "xmalloc.h"
+#include "ssh2.h"
#include "buffer.h"
-#include "bufaux.h"
#include "packet.h"
#include "compat.h"
#include "cipher.h"
-#include "kex.h"
#include "key.h"
+#include "kex.h"
#include "log.h"
#include "mac.h"
#include "match.h"
#define KEX_COOKIE_LEN 16
+#if OPENSSL_VERSION_NUMBER >= 0x00907000L
+# if defined(HAVE_EVP_SHA256)
+# define evp_ssh_sha256 EVP_sha256
+# else
+extern const EVP_MD *evp_ssh_sha256(void);
+# endif
+#endif
+
/* prototype */
static void kex_kexinit_finish(Kex *);
static void kex_choose_conf(Kex *);
int i;
char **proposal;
- proposal = xmalloc(PROPOSAL_MAX * sizeof(char *));
+ proposal = xcalloc(PROPOSAL_MAX, sizeof(char *));
buffer_init(&b);
buffer_append(&b, buffer_ptr(raw), buffer_len(raw));
{
Kex *kex;
- kex = xmalloc(sizeof(*kex));
- memset(kex, 0, sizeof(*kex));
+ kex = xcalloc(1, sizeof(*kex));
buffer_init(&kex->peer);
buffer_init(&kex->my);
kex_prop2buf(&kex->my, proposal);
enc->key_len = cipher_keylen(enc->cipher);
enc->block_size = cipher_blocksize(enc->cipher);
}
+
static void
choose_mac(Mac *mac, char *client, char *server)
{
mac->key = NULL;
mac->enabled = 0;
}
+
static void
choose_comp(Comp *comp, char *client, char *server)
{
}
comp->name = name;
}
+
static void
choose_kex(Kex *k, char *client, char *server)
{
fatal("no kex alg");
if (strcmp(k->name, KEX_DH1) == 0) {
k->kex_type = KEX_DH_GRP1_SHA1;
+ k->evp_md = EVP_sha1();
} else if (strcmp(k->name, KEX_DH14) == 0) {
k->kex_type = KEX_DH_GRP14_SHA1;
- } else if (strcmp(k->name, KEX_DHGEX) == 0) {
+ k->evp_md = EVP_sha1();
+ } else if (strcmp(k->name, KEX_DHGEX_SHA1) == 0) {
k->kex_type = KEX_DH_GEX_SHA1;
+ k->evp_md = EVP_sha1();
+#if OPENSSL_VERSION_NUMBER >= 0x00907000L
+ } else if (strcmp(k->name, KEX_DHGEX_SHA256) == 0) {
+ k->kex_type = KEX_DH_GEX_SHA256;
+ k->evp_md = evp_ssh_sha256();
+#endif
#ifdef GSSAPI
} else if (strncmp(k->name, KEX_GSS_GEX_SHA1_ID,
- sizeof(KEX_GSS_GEX_SHA1_ID)-1) == 0) {
+ sizeof(KEX_GSS_GEX_SHA1_ID) - 1) == 0) {
k->kex_type = KEX_GSS_GEX_SHA1;
- } else if (strncmp(k->name, KEX_GSS_GRP1_SHA1_ID,
- sizeof(KEX_GSS_GRP1_SHA1_ID)-1) == 0) {
+ k->evp_md = EVP_sha1();
+ } else if (strncmp(k->name, KEX_GSS_GRP1_SHA1_ID,
+ sizeof(KEX_GSS_GRP1_SHA1_ID) - 1) == 0) {
k->kex_type = KEX_GSS_GRP1_SHA1;
+ k->evp_md = EVP_sha1();
+ } else if (strncmp(k->name, KEX_GSS_GRP14_SHA1_ID,
+ sizeof(KEX_GSS_GRP14_SHA1_ID) - 1) == 0) {
+ k->kex_type = KEX_GSS_GRP14_SHA1;
+ k->evp_md = EVP_sha1();
#endif
} else
fatal("bad kex alg %s", k->name);
}
+
static void
choose_hostkeyalg(Kex *k, char *client, char *server)
{
/* Algorithm Negotiation */
for (mode = 0; mode < MODE_MAX; mode++) {
- newkeys = xmalloc(sizeof(*newkeys));
- memset(newkeys, 0, sizeof(*newkeys));
+ newkeys = xcalloc(1, sizeof(*newkeys));
kex->newkeys[mode] = newkeys;
ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN);
nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC;
}
static u_char *
-derive_key(Kex *kex, int id, u_int need, u_char *hash, BIGNUM *shared_secret)
+derive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen,
+ BIGNUM *shared_secret)
{
Buffer b;
- const EVP_MD *evp_md = EVP_sha1();
EVP_MD_CTX md;
char c = id;
u_int have;
- int mdsz = EVP_MD_size(evp_md);
+ int mdsz;
u_char *digest;
- if (mdsz < 0)
- fatal("derive_key: mdsz < 0");
+ if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0)
+ fatal("bad kex md size %d", mdsz);
digest = xmalloc(roundup(need, mdsz));
buffer_init(&b);
buffer_put_bignum2(&b, shared_secret);
/* K1 = HASH(K || H || "A" || session_id) */
- EVP_DigestInit(&md, evp_md);
+ EVP_DigestInit(&md, kex->evp_md);
if (!(datafellows & SSH_BUG_DERIVEKEY))
EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
- EVP_DigestUpdate(&md, hash, mdsz);
+ EVP_DigestUpdate(&md, hash, hashlen);
EVP_DigestUpdate(&md, &c, 1);
EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len);
EVP_DigestFinal(&md, digest, NULL);
* Key = K1 || K2 || ... || Kn
*/
for (have = mdsz; need > have; have += mdsz) {
- EVP_DigestInit(&md, evp_md);
+ EVP_DigestInit(&md, kex->evp_md);
if (!(datafellows & SSH_BUG_DERIVEKEY))
EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
- EVP_DigestUpdate(&md, hash, mdsz);
+ EVP_DigestUpdate(&md, hash, hashlen);
EVP_DigestUpdate(&md, digest, have);
EVP_DigestFinal(&md, digest + have, NULL);
}
#define NKEYS 6
void
-kex_derive_keys(Kex *kex, u_char *hash, BIGNUM *shared_secret)
+kex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret)
{
u_char *keys[NKEYS];
u_int i, mode, ctos;
- for (i = 0; i < NKEYS; i++)
- keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, shared_secret);
+ for (i = 0; i < NKEYS; i++) {
+ keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen,
+ shared_secret);
+ }
debug2("kex_derive_keys");
for (mode = 0; mode < MODE_MAX; mode++) {
current_keys[mode] = kex->newkeys[mode];
kex->newkeys[mode] = NULL;
- ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN);
+ ctos = (!kex->server && mode == MODE_OUT) ||
+ (kex->server && mode == MODE_IN);
current_keys[mode]->enc.iv = keys[ctos ? 0 : 1];
current_keys[mode]->enc.key = keys[ctos ? 2 : 3];
current_keys[mode]->mac.key = keys[ctos ? 4 : 5];