4 files changed, 26 insertions, 13 deletions

diff --git a/src/inbound_group_session.c b/src/inbound_group_session.c
index bf00008..a54e55f 100644
--- a/src/inbound_group_session.c
+++ b/src/inbound_group_session.c
@@ -263,7 +263,8 @@ size_t olm_group_decrypt_max_plaintext_length(
 static size_t _decrypt(
     OlmInboundGroupSession *session,
     uint8_t * message, size_t message_length,
-    uint8_t * plaintext, size_t max_plaintext_length
+    uint8_t * plaintext, size_t max_plaintext_length,
+    uint32_t * message_index
 ) {
     struct _OlmDecodeGroupMessageResults decoded_results;
     size_t max_length, r;
@@ -286,6 +287,10 @@ static size_t _decrypt(
         return (size_t)-1;
     }
 
+    if (message_index != NULL) {
+        *message_index = decoded_results.message_index;
+    }
+
     /* verify the signature. We could do this before decoding the message, but
      * we allow for the possibility of future protocol versions which use a
      * different signing mechanism; we would rather throw "BAD_MESSAGE_VERSION"
@@ -349,7 +354,8 @@ static size_t _decrypt(
 size_t olm_group_decrypt(
     OlmInboundGroupSession *session,
     uint8_t * message, size_t message_length,
-    uint8_t * plaintext, size_t max_plaintext_length
+    uint8_t * plaintext, size_t max_plaintext_length,
+    uint32_t * message_index
 ) {
     size_t raw_message_length;
 
@@ -361,7 +367,8 @@ size_t olm_group_decrypt(
 
     return _decrypt(
         session, message, raw_message_length,
-        plaintext, max_plaintext_length
+        plaintext, max_plaintext_length,
+        message_index
     );
 }
 
diff --git a/src/message.cpp b/src/message.cpp
index 05fe2c7..1c11a4a 100644
--- a/src/message.cpp
+++ b/src/message.cpp
@@ -214,11 +214,13 @@ void olm::decode_message(
     reader.ciphertext = nullptr;
     reader.ciphertext_length = 0;
 
-    if (pos == end) return;
     if (input_length < mac_length) return;
+
+    if (pos == end) return;
     reader.version = *(pos++);
 
     while (pos != end) {
+        unknown = pos;
         pos = decode(
             pos, end, RATCHET_KEY_TAG,
             reader.ratchet_key, reader.ratchet_key_length
@@ -234,7 +236,6 @@ void olm::decode_message(
         if (unknown == pos) {
             pos = skip_unknown(pos, end);
         }
-        unknown = pos;
     }
 }
 
@@ -303,6 +304,7 @@ void olm::decode_one_time_key_message(
     reader.version = *(pos++);
 
     while (pos != end) {
+        unknown = pos;
         pos = decode(
             pos, end, ONE_TIME_KEY_ID_TAG,
             reader.one_time_key, reader.one_time_key_length
@@ -322,7 +324,6 @@ void olm::decode_one_time_key_message(
         if (unknown == pos) {
             pos = skip_unknown(pos, end);
         }
-        unknown = pos;
     }
 }
 
@@ -377,9 +378,12 @@ void _olm_decode_group_message(
     results->ciphertext_length = 0;
 
     if (input_length < trailer_length) return;
+
+    if (pos == end) return;
     results->version = *(pos++);
 
     while (pos != end) {
+        unknown = pos;
         pos = decode(
             pos, end, GROUP_MESSAGE_INDEX_TAG,
             results->message_index, has_message_index
@@ -391,7 +395,6 @@ void _olm_decode_group_message(
         if (unknown == pos) {
             pos = skip_unknown(pos, end);
         }
-        unknown = pos;
     }
 
     results->has_message_index = (int)has_message_index;
diff --git a/src/outbound_group_session.c b/src/outbound_group_session.c
index 4e4561a..ae45694 100644
--- a/src/outbound_group_session.c
+++ b/src/outbound_group_session.c
@@ -154,20 +154,23 @@ size_t olm_init_outbound_group_session_random_length(
 
 size_t olm_init_outbound_group_session(
     OlmOutboundGroupSession *session,
-    uint8_t const * random, size_t random_length
+    uint8_t *random, size_t random_length
 ) {
+    const uint8_t *random_ptr = random;
+
     if (random_length < olm_init_outbound_group_session_random_length(session)) {
         /* Insufficient random data for new session */
         session->last_error = OLM_NOT_ENOUGH_RANDOM;
         return (size_t)-1;
     }
 
-    megolm_init(&(session->ratchet), random, 0);
-    random += MEGOLM_RATCHET_LENGTH;
+    megolm_init(&(session->ratchet), random_ptr, 0);
+    random_ptr += MEGOLM_RATCHET_LENGTH;
 
-    _olm_crypto_ed25519_generate_key(random, &(session->signing_key));
-    random += ED25519_RANDOM_LENGTH;
+    _olm_crypto_ed25519_generate_key(random_ptr, &(session->signing_key));
+    random_ptr += ED25519_RANDOM_LENGTH;
 
+    _olm_unset(random, random_length);
     return 0;
 }
 
diff --git a/src/pickle_encoding.c b/src/pickle_encoding.c
index 5d5f8d7..a56e9e3 100644
--- a/src/pickle_encoding.c
+++ b/src/pickle_encoding.c
@@ -60,7 +60,7 @@ size_t _olm_enc_output(
         raw_output, length
     );
     _olm_encode_base64(raw_output, length, output);
-    return raw_length;
+    return base64_length;
 }