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WOWW: Add better support out of order parsing

This commit is contained in:
Gtker 2021-07-16 13:59:16 +02:00 committed by Wireshark GitLab Utility
parent 3f4ac5539b
commit b9a6268819
1 changed files with 40 additions and 22 deletions
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62
epan/dissectors/packet-woww.c
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@ -1957,10 +1957,10 @@ deduce_header(guint8 session_key[WOWW_SESSION_KEY_LENGTH],
static gboolean static gboolean
session_key_is_fully_deduced(const bool known_indices[WOWW_SESSION_KEY_LENGTH], session_key_is_fully_deduced(const bool known_indices[WOWW_SESSION_KEY_LENGTH],
guint8 header_length, guint8 header_length,
WowwParticipant_t* participant) { guint8 start_index) {
gboolean fully_deduced = true; gboolean fully_deduced = true;
for (guint8 i = 0; i < header_length; i++) { for (guint8 i = 0; i < header_length; i++) {
if (!known_indices[(participant->index + i) % WOWW_SESSION_KEY_LENGTH]) { if (!known_indices[(start_index + i) % WOWW_SESSION_KEY_LENGTH]) {
fully_deduced = false; fully_deduced = false;
} }
} }
@ -2002,39 +2002,57 @@ handle_packet_header(packet_info* pinfo,
return decrypted_header; return decrypted_header;
} }
// If we aren't ready to fully decrypt this header yet guint8* original_header_values = wmem_tree_lookup32(wowwConversation->headers_need_decryption, pinfo->num);
if (!session_key_is_fully_deduced(wowwConversation->known_indices, headerSize, participant)) {
// Packet isn't decrypted, make sure to do it later
guint8 *array_index = wmem_alloc(wmem_file_scope(), 2);
array_index[0] = participant->index;
array_index[1] = participant->last_encrypted_value;
wmem_tree_insert32(wowwConversation->headers_need_decryption, pinfo->num, array_index);
if (WOWW_CLIENT_TO_SERVER) { if (original_header_values) {
deduce_header(wowwConversation->session_key, wowwConversation->known_indices, header, participant); // Header has been seen before
} else {
// Skip the packet, but remember to acknowledge that values changed // Original value will need to be used
participant->index = (participant->index + headerSize) % WOWW_SESSION_KEY_LENGTH; if (!session_key_is_fully_deduced(wowwConversation->known_indices, headerSize, original_header_values[0])) {
participant->last_encrypted_value = header[headerSize - 1]; // Not ready yet
return NULL;
} }
return NULL; // Header can be decrypted and added to map
}
guint8* old_index = wmem_tree_lookup32(wowwConversation->headers_need_decryption, pinfo->num); }
else {
// Header has not been seen before
if (!session_key_is_fully_deduced(wowwConversation->known_indices, headerSize, participant->index)) {
// Packet isn't decrypted, make sure to do it later
guint8 *array_index = wmem_alloc(wmem_file_scope(), 2);
array_index[0] = participant->index;
array_index[1] = participant->last_encrypted_value;
wmem_tree_insert32(wowwConversation->headers_need_decryption, pinfo->num, array_index);
if (WOWW_CLIENT_TO_SERVER) {
deduce_header(wowwConversation->session_key, wowwConversation->known_indices, header, participant);
} else {
// Skip the packet, but remember to acknowledge that values changed
participant->index = (participant->index + headerSize) % WOWW_SESSION_KEY_LENGTH;
participant->last_encrypted_value = header[headerSize - 1];
}
return NULL;
}
else {
// Header can be decrypted and added to map
}
}
guint8 new_index = participant->index; guint8 new_index = participant->index;
guint8 new_last_encrypted = participant->last_encrypted_value; guint8 new_last_encrypted = participant->last_encrypted_value;
// If this is an out of order packet we must use the original state // If this is an out of order packet we must use the original state
if (old_index) { if (original_header_values) {
participant->index = old_index[0]; participant->index = original_header_values[0];
participant->last_encrypted_value = old_index[1]; participant->last_encrypted_value = original_header_values[1];
} }
decrypted_header = get_decrypted_header(wowwConversation->session_key, participant, header, headerSize); decrypted_header = get_decrypted_header(wowwConversation->session_key, participant, header, headerSize);
if (old_index) { if (original_header_values) {
participant->index = new_index; participant->index = new_index;
participant->last_encrypted_value = new_last_encrypted; participant->last_encrypted_value = new_last_encrypted;