Use IV length of a crypter instead of block size for IV calculations

src/pluto/demux.c

@@ -1782,7 +1782,7 @@ process_packet(struct msg_digest **mdp)
 		 * the last phase 1 block, not the last block sent.
 		 */
 		{
-			size_t crypter_block_size;
+			size_t crypter_block_size, crypter_iv_size;
 			encryption_algorithm_t enc_alg;
 			crypter_t *crypter;
 			chunk_t data, iv;
@@ -1791,6 +1791,7 @@ process_packet(struct msg_digest **mdp)
 			enc_alg = oakley_to_encryption_algorithm(st->st_oakley.encrypt);
 			crypter = lib->crypto->create_crypter(lib->crypto, enc_alg, st->st_enc_key.len);
 			crypter_block_size = crypter->get_block_size(crypter);
+			crypter_iv_size = crypter->get_iv_size(crypter);
 
 			if (pbs_left(&md->message_pbs) % crypter_block_size != 0)
 			{
@@ -1817,17 +1818,17 @@ process_packet(struct msg_digest **mdp)
 			}
 
 			/* form iv by truncation */
-			st->st_new_iv_len = crypter_block_size;
+			st->st_new_iv_len = crypter_iv_size;
 			iv = chunk_create(st->st_new_iv, st->st_new_iv_len);
-			new_iv = alloca(crypter_block_size);
-			memcpy(new_iv, data.ptr + data.len - crypter_block_size,
-				   crypter_block_size);
+			new_iv = alloca(crypter_iv_size);
+			memcpy(new_iv, data.ptr + data.len - crypter_iv_size,
+				   crypter_iv_size);
 
 			crypter->set_key(crypter, st->st_enc_key);
 			crypter->decrypt(crypter, data, iv, NULL);
 			crypter->destroy(crypter);
 
-		memcpy(st->st_new_iv, new_iv, crypter_block_size);
+			memcpy(st->st_new_iv, new_iv, crypter_iv_size);
 			if (restore_iv)
 			{
 				memcpy(st->st_new_iv, new_iv, new_iv_len);

src/pluto/ipsec_doi.c

@@ -1753,7 +1753,7 @@ bool encrypt_message(pb_stream *pbs, struct state *st)
 	size_t enc_len = pbs_offset(pbs) - sizeof(struct isakmp_hdr);
 	chunk_t data, iv;
     char *new_iv;
-	size_t crypter_block_size;
+	size_t crypter_block_size, crypter_iv_size;
 	encryption_algorithm_t enc_alg;
 	crypter_t *crypter;
 
@@ -1761,6 +1761,7 @@ bool encrypt_message(pb_stream *pbs, struct state *st)
 	enc_alg = oakley_to_encryption_algorithm(st->st_oakley.encrypt);
 	crypter = lib->crypto->create_crypter(lib->crypto, enc_alg, st->st_enc_key.len);
 	crypter_block_size = crypter->get_block_size(crypter);
+	crypter_iv_size = crypter->get_iv_size(crypter);
 
 	/* Pad up to multiple of encryption blocksize.
 	 * See the description associated with the definition of
@@ -1781,15 +1782,15 @@ bool encrypt_message(pb_stream *pbs, struct state *st)
 	data = chunk_create(enc_start, enc_len);
 
 	/* form iv by truncation */
-	st->st_new_iv_len = crypter_block_size;
+	st->st_new_iv_len = crypter_iv_size;
 	iv = chunk_create(st->st_new_iv, st->st_new_iv_len);
 
 	crypter->set_key(crypter, st->st_enc_key);
 	crypter->encrypt(crypter, data, iv, NULL);
 	crypter->destroy(crypter);
 
-	new_iv = data.ptr + data.len - crypter_block_size;
-	memcpy(st->st_new_iv, new_iv, crypter_block_size);
+	new_iv = data.ptr + data.len - crypter_iv_size;
+	memcpy(st->st_new_iv, new_iv, crypter_iv_size);
 	update_iv(st);
 	DBG_cond_dump(DBG_CRYPT, "next IV:", st->st_iv, st->st_iv_len);
 	close_message(pbs);

src/pluto/pkcs7.c

@@ -473,7 +473,7 @@ end:
 			DBG1(DBG_LIB, "symmetric key length %d is wrong", symmetric_key.len);
 			goto failed;
 		}
-		if (iv.len != crypter->get_block_size(crypter))
+		if (iv.len != crypter->get_iv_size(crypter))
 		{
 			DBG1(DBG_LIB, "IV length %d is wrong", iv.len);
 			goto failed;
@@ -668,7 +668,7 @@ chunk_t pkcs7_build_envelopedData(chunk_t data, certificate_t *cert, int enc_alg
 		rng->destroy(rng);
 
 		rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
-		rng->allocate_bytes(rng, crypter->get_block_size(crypter), &iv);
+		rng->allocate_bytes(rng, crypter->get_iv_size(crypter), &iv);
 		DBG4(DBG_LIB, "initialization vector: %B", &iv);
 		rng->destroy(rng);
 	}