--- a/common-kex.c	Wed May 16 21:56:50 2012 +0800
+++ b/common-kex.c	Wed May 16 22:54:51 2012 +0800
@@ -293,7 +293,6 @@
 	hash_state hs;
 	unsigned int C2S_keysize, S2C_keysize;
 	char mactransletter, macrecvletter; /* Client or server specific */
-	int recv_cipher = 0, trans_cipher = 0;
 
 	TRACE(("enter gen_new_keys"))
 	/* the dh_K and hash are the start of all hashes, we make use of that */
@@ -330,31 +329,39 @@
 	hashkeys(C2S_key, C2S_keysize, &hs, 'C');
 	hashkeys(S2C_key, S2C_keysize, &hs, 'D');
 
-	recv_cipher = find_cipher(ses.newkeys->recv.algo_crypt->cipherdesc->name);
-	if (recv_cipher < 0)
-	    dropbear_exit("Crypto error");
-	if (ses.newkeys->recv.crypt_mode->start(recv_cipher, 
-			recv_IV, recv_key, 
-			ses.newkeys->recv.algo_crypt->keysize, 0, 
-			&ses.newkeys->recv.cipher_state) != CRYPT_OK) {
-		dropbear_exit("Crypto error");
+	if (ses.newkeys->recv.algo_crypt->cipherdesc != NULL) {
+		int recv_cipher = find_cipher(ses.newkeys->recv.algo_crypt->cipherdesc->name);
+		if (recv_cipher < 0)
+			dropbear_exit("Crypto error");
+		if (ses.newkeys->recv.crypt_mode->start(recv_cipher, 
+				recv_IV, recv_key, 
+				ses.newkeys->recv.algo_crypt->keysize, 0, 
+				&ses.newkeys->recv.cipher_state) != CRYPT_OK) {
+			dropbear_exit("Crypto error");
+		}
 	}
 
-	trans_cipher = find_cipher(ses.newkeys->trans.algo_crypt->cipherdesc->name);
-	if (trans_cipher < 0)
-	    dropbear_exit("Crypto error");
-	if (ses.newkeys->trans.crypt_mode->start(trans_cipher, 
-			trans_IV, trans_key, 
-			ses.newkeys->trans.algo_crypt->keysize, 0, 
-			&ses.newkeys->trans.cipher_state) != CRYPT_OK) {
-		dropbear_exit("Crypto error");
+	if (ses.newkeys->trans.algo_crypt->cipherdesc != NULL) {
+		int trans_cipher = find_cipher(ses.newkeys->trans.algo_crypt->cipherdesc->name);
+		if (trans_cipher < 0)
+			dropbear_exit("Crypto error");
+		if (ses.newkeys->trans.crypt_mode->start(trans_cipher, 
+				trans_IV, trans_key, 
+				ses.newkeys->trans.algo_crypt->keysize, 0, 
+				&ses.newkeys->trans.cipher_state) != CRYPT_OK) {
+			dropbear_exit("Crypto error");
+		}
 	}
-	
+
 	/* MAC keys */
-	hashkeys(ses.newkeys->trans.mackey, 
-			ses.newkeys->trans.algo_mac->keysize, &hs, mactransletter);
-	hashkeys(ses.newkeys->recv.mackey, 
-			ses.newkeys->recv.algo_mac->keysize, &hs, macrecvletter);
+	if (ses.newkeys->trans.algo_mac->hashdesc != NULL) {
+		hashkeys(ses.newkeys->trans.mackey, 
+				ses.newkeys->trans.algo_mac->keysize, &hs, mactransletter);
+	}
+	if (ses.newkeys->recv.algo_mac->hashdesc != NULL) {
+		hashkeys(ses.newkeys->recv.mackey, 
+				ses.newkeys->recv.algo_mac->keysize, &hs, macrecvletter);
+	}
 	ses.newkeys->trans.hash_index = find_hash(ses.newkeys->trans.algo_mac->hashdesc->name),
 	ses.newkeys->recv.hash_index = find_hash(ses.newkeys->recv.algo_mac->hashdesc->name),