--- a/svr-kex.c	Tue Jul 20 12:06:37 2004 +0000
+++ b/svr-kex.c	Mon Jul 26 02:44:20 2004 +0000
@@ -70,87 +70,15 @@
  * See the ietf-secsh-transport draft, section 6, for details */
 static void send_msg_kexdh_reply(mp_int *dh_e) {
 
-	mp_int dh_p, dh_q, dh_g, dh_y, dh_f;
-	unsigned char randbuf[DH_P_LEN];
-	int dh_q_len;
-	hash_state hs;
+	mp_int dh_y, dh_f;
 
 	TRACE(("enter send_msg_kexdh_reply"));
 	
-	m_mp_init_multi(&dh_g, &dh_p, &dh_q, &dh_y, &dh_f, NULL);
-
-	/* read the prime and generator*/
-	if (mp_read_unsigned_bin(&dh_p, (unsigned char*)dh_p_val, DH_P_LEN)
-			!= MP_OKAY) {
-		dropbear_exit("Diffie-Hellman error");
-	}
-	
-	if (mp_set_int(&dh_g, DH_G_VAL) != MP_OKAY) {
-		dropbear_exit("Diffie-Hellman error");
-	}
-
-	/* calculate q = (p-1)/2 */
-	if (mp_sub_d(&dh_p, 1, &dh_y) != MP_OKAY) { /*dh_y is just a temp var here*/
-		dropbear_exit("Diffie-Hellman error");
-	}
-	if (mp_div_2(&dh_y, &dh_q) != MP_OKAY) {
-		dropbear_exit("Diffie-Hellman error");
-	}
-
-	dh_q_len = mp_unsigned_bin_size(&dh_q);
-
-	/* calculate our random value dh_y */
-	do {
-		assert((unsigned int)dh_q_len <= sizeof(randbuf));
-		genrandom(randbuf, dh_q_len);
-		if (mp_read_unsigned_bin(&dh_y, randbuf, dh_q_len) != MP_OKAY) {
-			dropbear_exit("Diffie-Hellman error");
-		}
-	} while (mp_cmp(&dh_y, &dh_q) == MP_GT || mp_cmp_d(&dh_y, 0) != MP_GT);
-
-	/* f = g^y mod p */
-	if (mp_exptmod(&dh_g, &dh_y, &dh_p, &dh_f) != MP_OKAY) {
-		dropbear_exit("Diffie-Hellman error");
-	}
-	mp_clear(&dh_g);
+	gen_kexdh_vals(&dh_f, &dh_y);
 
-	/* K = e^y mod p */
-	ses.dh_K = (mp_int*)m_malloc(sizeof(mp_int));
-	m_mp_init(ses.dh_K);
-	if (mp_exptmod(dh_e, &dh_y, &dh_p, ses.dh_K) != MP_OKAY) {
-		dropbear_exit("Diffie-Hellman error");
-	}
-
-	/* clear no longer needed vars */
-	mp_clear_multi(&dh_y, &dh_p, &dh_q, NULL);
+	kexdh_comb_key(&dh_f, &dh_y, dh_e, svr_opts.hostkey);
+	mp_clear(&dh_y);
 
-	/* Create the remainder of the hash buffer, to generate the exchange hash */
-	/* K_S, the host key */
-	buf_put_pub_key(ses.kexhashbuf, svr_opts.hostkey, 
-			ses.newkeys->algo_hostkey);
-	/* e, exchange value sent by the client */
-	buf_putmpint(ses.kexhashbuf, dh_e);
-	/* f, exchange value sent by the server */
-	buf_putmpint(ses.kexhashbuf, &dh_f);
-	/* K, the shared secret */
-	buf_putmpint(ses.kexhashbuf, ses.dh_K);
-
-	/* calculate the hash H to sign */
-	sha1_init(&hs);
-	buf_setpos(ses.kexhashbuf, 0);
-	sha1_process(&hs, buf_getptr(ses.kexhashbuf, ses.kexhashbuf->len),
-			ses.kexhashbuf->len);
-	sha1_done(&hs, ses.hash);
-	buf_free(ses.kexhashbuf);
-	ses.kexhashbuf = NULL;
-	
-	/* first time around, we set the session_id to H */
-	if (ses.session_id == NULL) {
-		/* create the session_id, this never needs freeing */
-		ses.session_id = (unsigned char*)m_malloc(SHA1_HASH_SIZE);
-		memcpy(ses.session_id, ses.hash, SHA1_HASH_SIZE);
-	}
-	
 	/* we can start creating the kexdh_reply packet */
 	CHECKCLEARTOWRITE();
 	buf_putbyte(ses.writepayload, SSH_MSG_KEXDH_REPLY);
@@ -171,105 +99,3 @@
 	TRACE(("leave send_msg_kexdh_reply"));
 }
 
-/* read the client's choice of algorithms */
-void svr_read_kex() {
-
-	algo_type * algo;
-	char * erralgo = NULL;
-
-	int goodguess = 0;
-	int allgood = 1; /* we AND this with each goodguess and see if its still
-						true after */
-
-	buf_incrpos(ses.payload, 16); /* start after the cookie */
-
-	ses.newkeys = (struct key_context*)m_malloc(sizeof(struct key_context));
-
-	/* kex_algorithms */
-	algo = svr_buf_match_algo(ses.payload, sshkex, &goodguess);
-	allgood &= goodguess;
-	if (algo == NULL) {
-		erralgo = "kex";
-		goto error;
-	}
-	ses.newkeys->algo_kex = algo->val;
-
-	/* server_host_key_algorithms */
-	algo = svr_buf_match_algo(ses.payload, sshhostkey, &goodguess);
-	allgood &= goodguess;
-	if (algo == NULL) {
-		erralgo = "hostkey";
-		goto error;
-	}
-	ses.newkeys->algo_hostkey = algo->val;
-
-	/* encryption_algorithms_client_to_server */
-	algo = svr_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;
-
-	/* encryption_algorithms_server_to_client */
-	algo = svr_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;
-
-	/* mac_algorithms_client_to_server */
-	algo = svr_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;
-
-	/* mac_algorithms_server_to_client */
-	algo = svr_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;
-
-	/* compression_algorithms_client_to_server */
-	algo = svr_buf_match_algo(ses.payload, sshcompress, &goodguess);
-	if (algo == NULL) {
-		erralgo = "comp c->s";
-		goto error;
-	}
-	ses.newkeys->recv_algo_comp = algo->val;
-
-	/* compression_algorithms_server_to_client */
-	algo = svr_buf_match_algo(ses.payload, sshcompress, &goodguess);
-	if (algo == NULL) {
-		erralgo = "comp s->c";
-		goto error;
-	}
-	ses.newkeys->trans_algo_comp = algo->val;
-
-	/* languages_client_to_server */
-	buf_eatstring(ses.payload);
-
-	/* languages_server_to_client */
-	buf_eatstring(ses.payload);
-
-	/* first_kex_packet_follows */
-	if (buf_getbyte(ses.payload)) {
-		ses.kexstate.firstfollows = 1;
-		/* if the guess wasn't good, we ignore the packet sent */
-		if (!allgood) {
-			ses.ignorenext = 1;
-		}
-	}
-
-	/* reserved for future extensions */
-	buf_getint(ses.payload);
-	return;
-
-error:
-	dropbear_exit("no matching algo %s", erralgo);
-}