forgot -kb, remove openssl/ssl conditional
diff --git a/kex.c b/kex.c
new file mode 100644
index 0000000..114df78
--- /dev/null
+++ b/kex.c
@@ -0,0 +1,424 @@
+/*
+ * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by Markus Friedl.
+ * 4. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+RCSID("$Id: kex.c,v 1.7 2000/04/16 01:52:47 damien Exp $");
+
+#include "ssh.h"
+#include "ssh2.h"
+#include "xmalloc.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "cipher.h"
+#include "compat.h"
+
+#include <openssl/bn.h>
+#include <openssl/dh.h>
+
+#include <openssl/crypto.h>
+#include <openssl/bio.h>
+#include <openssl/bn.h>
+#include <openssl/dh.h>
+#include <openssl/pem.h>
+
+#include "kex.h"
+
+Buffer *
+kex_init(char *myproposal[PROPOSAL_MAX])
+{
+ char c = 0;
+ unsigned char cookie[16];
+ u_int32_t rand = 0;
+ int i;
+ Buffer *ki = xmalloc(sizeof(*ki));
+ for (i = 0; i < 16; i++) {
+ if (i % 4 == 0)
+ rand = arc4random();
+ cookie[i] = rand & 0xff;
+ rand >>= 8;
+ }
+ buffer_init(ki);
+ buffer_append(ki, (char *)cookie, sizeof cookie);
+ for (i = 0; i < PROPOSAL_MAX; i++)
+ buffer_put_cstring(ki, myproposal[i]);
+ buffer_append(ki, &c, 1); /* boolean first_kex_packet_follows */
+ buffer_put_int(ki, 0); /* uint32 0 (reserved for future extension) */
+ return ki;
+}
+
+/* diffie-hellman-group1-sha1 */
+
+int
+dh_pub_is_valid(DH *dh, BIGNUM *dh_pub)
+{
+ int i;
+ 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;
+ }
+ for (i = 0; i <= n; i++)
+ if (BN_is_bit_set(dh_pub, i))
+ bits_set++;
+ debug("bits set: %d/%d", bits_set, BN_num_bits(dh->p));
+
+ /* if g==2 and bits_set==1 then computing log_g(dh_pub) is trivial */
+ if (bits_set > 1 && (BN_cmp(dh_pub, dh->p) == -1))
+ return 1;
+ log("invalid public DH value (%d/%d)", bits_set, BN_num_bits(dh->p));
+ return 0;
+}
+
+DH *
+dh_new_group1()
+{
+ 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);
+ do {
+ if (DH_generate_key(dh) == 0)
+ fatal("DH_generate_key");
+ if (tries++ > 10)
+ fatal("dh_new_group1: too many bad keys: giving up");
+ } while (!dh_pub_is_valid(dh, dh->pub_key));
+ return dh;
+}
+
+void
+bignum_print(BIGNUM *b)
+{
+ BN_print_fp(stderr,b);
+}
+
+void
+dump_digest(unsigned char *digest, int len)
+{
+ int i;
+ for (i = 0; i< len; i++){
+ fprintf(stderr, "%02x", digest[i]);
+ if(i%2!=0)
+ fprintf(stderr, " ");
+ }
+ fprintf(stderr, "\n");
+}
+
+unsigned char *
+kex_hash(
+ char *client_version_string,
+ char *server_version_string,
+ char *ckexinit, int ckexinitlen,
+ char *skexinit, int skexinitlen,
+ char *serverhostkeyblob, int sbloblen,
+ 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_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)
+{
+ Buffer b;
+ EVP_MD *evp_md = EVP_sha1();
+ EVP_MD_CTX md;
+ char c = id;
+ int have;
+ int mdsz = evp_md->md_size;
+ unsigned char *digest = xmalloc(((need+mdsz-1)/mdsz)*mdsz);
+
+ buffer_init(&b);
+ buffer_put_bignum2(&b, shared_secret);
+
+ EVP_DigestInit(&md, evp_md);
+ 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_DigestFinal(&md, digest, NULL);
+
+ /* expand */
+ for (have = mdsz; need > have; have += mdsz) {
+ EVP_DigestInit(&md, evp_md);
+ EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
+ EVP_DigestUpdate(&md, hash, mdsz);
+ EVP_DigestUpdate(&md, digest, have);
+ EVP_DigestFinal(&md, digest + have, NULL);
+ }
+ buffer_free(&b);
+#ifdef DEBUG_KEX
+ fprintf(stderr, "Digest '%c'== ", c);
+ dump_digest(digest, need);
+#endif
+ return digest;
+}
+
+#define NKEYS 6
+
+#define MAX_PROP 20
+#define SEP ","
+
+char *
+get_match(char *client, char *server)
+{
+ char *sproposals[MAX_PROP];
+ char *p;
+ int i, j, nproposals;
+
+ for ((p = strtok(server, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
+ if (i < MAX_PROP)
+ sproposals[i] = p;
+ else
+ break;
+ }
+ nproposals = i;
+
+ for ((p = strtok(client, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
+ for (j = 0; j < nproposals; j++)
+ if (strcmp(p, sproposals[j]) == 0)
+ return xstrdup(p);
+ }
+ return NULL;
+}
+void
+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->name = name;
+ enc->enabled = 0;
+ enc->iv = NULL;
+ enc->key = NULL;
+}
+void
+choose_mac(Mac *mac, char *client, char *server)
+{
+ char *name = get_match(client, server);
+ if (name == NULL)
+ fatal("no matching mac found: client %s server %s", client, server);
+ if (strcmp(name, "hmac-md5") == 0) {
+ mac->md = EVP_md5();
+ } else if (strcmp(name, "hmac-sha1") == 0) {
+ mac->md = EVP_sha1();
+ } else if (strcmp(name, "hmac-ripemd160@openssh.com") == 0) {
+ mac->md = EVP_ripemd160();
+ } else {
+ fatal("unsupported mac %s", name);
+ }
+ mac->name = name;
+ mac->mac_len = mac->md->md_size;
+ mac->key_len = datafellows ? 16 : mac->mac_len;
+ mac->key = NULL;
+ mac->enabled = 0;
+}
+void
+choose_comp(Comp *comp, char *client, char *server)
+{
+ char *name = get_match(client, server);
+ if (name == NULL)
+ fatal("no matching comp found: client %s server %s", client, server);
+ if (strcmp(name, "zlib") == 0) {
+ comp->type = 1;
+ } else if (strcmp(name, "none") == 0) {
+ comp->type = 0;
+ } else {
+ fatal("unsupported comp %s", name);
+ }
+ comp->name = name;
+}
+void
+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)
+ fatal("bad kex alg %s", k->name);
+}
+void
+choose_hostkeyalg(Kex *k, char *client, char *server)
+{
+ k->hostkeyalg = get_match(client, server);
+ if (k->hostkeyalg == NULL)
+ fatal("no hostkey alg");
+ if (strcmp(k->hostkeyalg, KEX_DSS) != 0)
+ fatal("bad hostkey alg %s", k->hostkeyalg);
+}
+
+Kex *
+kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server)
+{
+ int i;
+ int mode;
+ int ctos; /* direction: if true client-to-server */
+ int need;
+ Kex *k;
+
+ k = xmalloc(sizeof(*k));
+ memset(k, 0, sizeof(*k));
+ k->server = server;
+
+ for (mode = 0; mode < MODE_MAX; mode++) {
+ int nenc, nmac, ncomp;
+ ctos = (!k->server && mode == MODE_OUT) || (k->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]);
+ debug("kex: %s %s %s %s",
+ ctos ? "client->server" : "server->client",
+ k->enc[mode].name,
+ k->mac[mode].name,
+ k->comp[mode].name);
+ }
+ choose_kex(k, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
+ choose_hostkeyalg(k, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
+ sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
+ for (i = 0; i < PROPOSAL_MAX; i++) {
+ xfree(cprop[i]);
+ xfree(sprop[i]);
+ }
+ 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->mac[mode].key_len)
+ need = k->mac[mode].key_len;
+ }
+ /* need runden? */
+#define WE_NEED 32
+ k->we_need = WE_NEED;
+ k->we_need = need;
+ return k;
+}
+
+int
+kex_derive_keys(Kex *k, unsigned char *hash, BIGNUM *shared_secret)
+{
+ int i;
+ int mode;
+ int ctos;
+ unsigned char *keys[NKEYS];
+
+ for (i = 0; i < NKEYS; i++)
+ keys[i] = derive_key('A'+i, k->we_need, hash, shared_secret);
+
+ 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];
+ }
+ return 0;
+}