1 files changed, 11 insertions, 27 deletions

diff --git a/src/methods/cipher_test/cipher_test.c b/src/methods/cipher_test/cipher_test.c
index 2516164..3241acf 100644
--- a/src/methods/cipher_test/cipher_test.c
+++ b/src/methods/cipher_test/cipher_test.c
@@ -117,13 +117,8 @@ static bool method_encrypt(fastd_context_t *ctx, fastd_peer_t *peer UNUSED, fast
 	if (tail_len)
 		memset(in.data+in.len, 0, tail_len);
 
-	size_t iv_length = session->method->cipher_info->iv_length;
-	uint8_t nonce[iv_length];
-	if (iv_length) {
-		memset(nonce, 0, iv_length);
-		memcpy(nonce, session->common.send_nonce, min_size_t(COMMON_NONCEBYTES, iv_length));
-		nonce[iv_length-1] = 1;
-	}
+	uint8_t nonce[session->method->cipher_info->iv_length];
+	fastd_method_expand_nonce(nonce, session->common.send_nonce, sizeof(nonce));
 
 	int n_blocks = block_count(in.len, sizeof(fastd_block128_t));
 
@@ -139,13 +134,9 @@ static bool method_encrypt(fastd_context_t *ctx, fastd_peer_t *peer UNUSED, fast
 
 	fastd_buffer_free(in);
 
-	fastd_buffer_pull_head(ctx, out, COMMON_HEADBYTES);
-
-	memcpy(out->data, session->common.send_nonce, COMMON_NONCEBYTES);
+	fastd_method_put_common_header(ctx, out, session->common.send_nonce, 0);
 	fastd_method_increment_nonce(&session->common);
 
-	((uint8_t*)out->data)[COMMON_NONCEBYTES] = 0; /* flags */
-
 	return true;
 }
 
@@ -156,24 +147,17 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho
 	if (!method_session_is_valid(ctx, session))
 		return false;
 
-	const uint8_t *common_nonce = in.data;
-
-	if (common_nonce[COMMON_NONCEBYTES]) /* flags */
+	uint8_t in_nonce[COMMON_NONCEBYTES];
+	uint8_t flags;
+	int64_t age;
+	if (!fastd_method_handle_common_header(ctx, &session->common, &in, in_nonce, &flags, &age))
 		return false;
 
-	size_t iv_length = session->method->cipher_info->iv_length;
-	uint8_t nonce[iv_length];
-	if (iv_length) {
-		memset(nonce, 0, iv_length);
-		memcpy(nonce, common_nonce, min_size_t(COMMON_NONCEBYTES, iv_length));
-		nonce[iv_length-1] = 1;
-	}
-
-	int64_t age;
-	if (!fastd_method_is_nonce_valid(ctx, &session->common, in.data, &age))
+	if (flags)
 		return false;
 
-	fastd_buffer_push_head(ctx, &in, COMMON_HEADBYTES);
+	uint8_t nonce[session->method->cipher_info->iv_length];
+	fastd_method_expand_nonce(nonce, in_nonce, sizeof(nonce));
 
 	size_t tail_len = alignto(in.len, sizeof(fastd_block128_t))-in.len;
 	*out = fastd_buffer_alloc(ctx, in.len, 0, tail_len);
@@ -190,7 +174,7 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho
 		return false;
 	}
 
-	if (!fastd_method_reorder_check(ctx, peer, &session->common, common_nonce, age)) {
+	if (!fastd_method_reorder_check(ctx, peer, &session->common, in_nonce, age)) {
 		fastd_buffer_free(*out);
 		*out = fastd_buffer_alloc(ctx, 0, 0, 0);
 	}