/* Parses channel payload returning new channel payload structure. */
-SilcChannelPayload silc_channel_payload_parse(SilcBuffer buffer)
+SilcChannelPayload silc_channel_payload_parse(const unsigned char *payload,
+ uint32 payload_len)
{
+ SilcBufferStruct buffer;
SilcChannelPayload new;
int ret;
SILC_LOG_DEBUG(("Parsing channel payload"));
+ silc_buffer_set(&buffer, (unsigned char *)payload, payload_len);
new = silc_calloc(1, sizeof(*new));
/* Parse the Channel Payload. Ignore the padding. */
- ret = silc_buffer_unformat(buffer,
+ ret = silc_buffer_unformat(&buffer,
SILC_STR_UI16_NSTRING_ALLOC(&new->channel_name,
&new->name_len),
SILC_STR_UI16_NSTRING_ALLOC(&new->channel_id,
if (ret == -1)
goto err;
- if ((new->name_len < 1 || new->name_len > buffer->len) ||
- (new->id_len < 1 || new->id_len > buffer->len)) {
+ if ((new->name_len < 1 || new->name_len > buffer.len) ||
+ (new->id_len < 1 || new->id_len > buffer.len)) {
SILC_LOG_ERROR(("Incorrect channel payload in packet, packet dropped"));
goto err;
}
/* Parses list of channel payloads returning list of payloads. */
-SilcDList silc_channel_payload_parse_list(SilcBuffer buffer)
+SilcDList silc_channel_payload_parse_list(const unsigned char *payload,
+ uint32 payload_len)
{
+ SilcBufferStruct buffer;
SilcDList list;
SilcChannelPayload new;
int len, ret;
SILC_LOG_DEBUG(("Parsing channel payload list"));
+ silc_buffer_set(&buffer, (unsigned char *)payload, payload_len);
list = silc_dlist_init();
- while (buffer->len) {
+ while (buffer.len) {
new = silc_calloc(1, sizeof(*new));
- ret = silc_buffer_unformat(buffer,
+ ret = silc_buffer_unformat(&buffer,
SILC_STR_UI16_NSTRING_ALLOC(&new->channel_name,
&new->name_len),
SILC_STR_UI16_NSTRING_ALLOC(&new->channel_id,
if (ret == -1)
goto err;
- if ((new->name_len < 1 || new->name_len > buffer->len) ||
- (new->id_len < 1 || new->id_len > buffer->len)) {
+ if ((new->name_len < 1 || new->name_len > buffer.len) ||
+ (new->id_len < 1 || new->id_len > buffer.len)) {
SILC_LOG_ERROR(("Incorrect channel payload in packet, packet dropped"));
goto err;
}
len = 2 + new->name_len + 2 + new->id_len + 4;
- if (buffer->len < len)
+ if (buffer.len < len)
break;
- silc_buffer_pull(buffer, len);
+ silc_buffer_pull(&buffer, len);
silc_dlist_add(list, new);
}
/* Encode new channel payload and returns it as buffer. */
-SilcBuffer silc_channel_payload_encode(unsigned char *channel_name,
+SilcBuffer silc_channel_payload_encode(const unsigned char *channel_name,
uint16 channel_name_len,
- unsigned char *channel_id,
+ const unsigned char *channel_id,
uint32 channel_id_len,
uint32 mode)
{
return buffer;
}
-/* Free's Channel Payload */
+/* Frees Channel Payload */
void silc_channel_payload_free(SilcChannelPayload payload)
{
while ((entry = silc_dlist_get(list)) != SILC_LIST_END) {
silc_free(entry->channel_name);
silc_free(entry->channel_id);
- silc_free(entry);
silc_dlist_del(list, entry);
+ silc_free(entry);
}
silc_dlist_uninit(list);
******************************************************************************/
+#define SILC_CHANNEL_MESSAGE_PAD(__payloadlen) (16 - (__payloadlen) % 16)
+
/* Channel Message Payload structure. Contents of this structure is parsed
from SILC packets. */
struct SilcChannelMessagePayloadStruct {
- uint16 flags;
+ SilcMessageFlags flags;
uint16 data_len;
unsigned char *data;
unsigned char *mac;
unsigned char *iv;
};
-/* Decrypts the channel message payload. */
+/* Decrypts the channel message payload. First push the IV out of the
+ packet. The IV is used in the decryption process. Then decrypt the
+ message. After decyprtion, take the MAC from the decrypted packet,
+ compute MAC and compare the MACs. If they match, the decryption was
+ successful and we have the channel message ready to be displayed. */
-int silc_channel_message_payload_decrypt(unsigned char *data,
- size_t data_len,
- SilcCipher cipher,
- SilcHmac hmac)
+bool silc_channel_message_payload_decrypt(unsigned char *data,
+ size_t data_len,
+ SilcCipher cipher,
+ SilcHmac hmac)
{
uint32 iv_len, mac_len;
unsigned char *end, *mac, mac2[32];
+ unsigned char *dst, iv[SILC_CIPHER_MAX_IV_SIZE];
- /* Decrypt the channel message. First push the IV out of the packet.
- The IV is used in the decryption process. Then decrypt the message.
- After decyprtion, take the MAC from the decrypted packet, compute MAC
- and compare the MACs. If they match, the decryption was successfull
- and we have the channel message ready to be displayed. */
+ /* Push the IV out of the packet, and copy the IV since we do not want
+ to modify the original data buffer. */
end = data + data_len;
-
- /* Push the IV out of the packet */
iv_len = silc_cipher_get_block_len(cipher);
+ memcpy(iv, end - iv_len, iv_len);
+
+ /* Allocate destination decryption buffer since we do not want to modify
+ the original data buffer, since we might want to call this function
+ many times for same payload. */
+ if (hmac)
+ dst = silc_calloc(data_len - iv_len, sizeof(*dst));
+ else
+ dst = data;
/* Decrypt the channel message */
- silc_cipher_decrypt(cipher, data, data, data_len - iv_len, (end - iv_len));
+ silc_cipher_decrypt(cipher, data, dst, data_len - iv_len, iv);
- /* Take the MAC */
if (hmac) {
+ /* Take the MAC */
+ end = dst + (data_len - iv_len);
mac_len = silc_hmac_len(hmac);
- mac = (end - iv_len - mac_len);
+ mac = (end - mac_len);
/* Check the MAC of the message */
SILC_LOG_DEBUG(("Checking channel message MACs"));
- silc_hmac_make(hmac, data, (data_len - iv_len - mac_len), mac2, &mac_len);
+ silc_hmac_make(hmac, dst, (data_len - iv_len - mac_len), mac2, &mac_len);
if (memcmp(mac, mac2, mac_len)) {
SILC_LOG_DEBUG(("Channel message MACs does not match"));
+ silc_free(dst);
return FALSE;
}
SILC_LOG_DEBUG(("MAC is Ok"));
+
+ /* Now copy the decrypted data into the buffer since it is verified
+ it decrypted correctly. */
+ memcpy(data, dst, data_len - iv_len);
+ memset(dst, 0, data_len - iv_len);
+ silc_free(dst);
}
return TRUE;
This also decrypts it and checks the MAC. */
SilcChannelMessagePayload
-silc_channel_message_payload_parse(SilcBuffer buffer,
+silc_channel_message_payload_parse(unsigned char *payload,
+ uint32 payload_len,
SilcCipher cipher,
SilcHmac hmac)
{
+ SilcBufferStruct buffer;
SilcChannelMessagePayload new;
int ret;
uint32 iv_len, mac_len;
SILC_LOG_DEBUG(("Parsing channel message payload"));
+ silc_buffer_set(&buffer, payload, payload_len);
+
/* Decrypt the payload */
- ret = silc_channel_message_payload_decrypt(buffer->data, buffer->len,
- cipher, hmac);
+ ret = silc_channel_message_payload_decrypt(buffer.data, buffer.len,
+ cipher, hmac);
if (ret == FALSE)
return NULL;
new = silc_calloc(1, sizeof(*new));
/* Parse the Channel Message Payload. Ignore the padding. */
- ret = silc_buffer_unformat(buffer,
+ ret = silc_buffer_unformat(&buffer,
SILC_STR_UI_SHORT(&new->flags),
SILC_STR_UI16_NSTRING_ALLOC(&new->data,
&new->data_len),
if (ret == -1)
goto err;
- if (new->data_len < 1 || new->data_len > buffer->len) {
+ if (new->data_len > buffer.len) {
SILC_LOG_ERROR(("Incorrect channel message payload in packet, "
"packet dropped"));
goto err;
SilcBuffer silc_channel_message_payload_encode(uint16 flags,
uint16 data_len,
- unsigned char *data,
+ const unsigned char *data,
uint16 iv_len,
unsigned char *iv,
SilcCipher cipher,
int i;
SilcBuffer buffer;
uint32 len, pad_len, mac_len;
- unsigned char pad[SILC_PACKET_MAX_PADLEN];
+ unsigned char pad[16];
unsigned char mac[32];
SILC_LOG_DEBUG(("Encoding channel message payload"));
since it is not encrypted. */
mac_len = silc_hmac_len(hmac);
len = 6 + data_len + mac_len;
- pad_len = SILC_PACKET_PADLEN((len + 2));
+ pad_len = SILC_CHANNEL_MESSAGE_PAD(len);
/* Allocate channel payload buffer */
len += pad_len + iv_len;
/* Return flags */
-uint16
+SilcMessageFlags
silc_channel_message_get_flags(SilcChannelMessagePayload payload)
{
return payload->flags;
/* Return MAC. The caller knows the length of the MAC */
-unsigned char *silc_channel_mesage_get_mac(SilcChannelMessagePayload payload)
+unsigned char *silc_channel_message_get_mac(SilcChannelMessagePayload payload)
{
return payload->mac;
}
/* Parses channel key payload returning new channel key payload structure */
-SilcChannelKeyPayload silc_channel_key_payload_parse(SilcBuffer buffer)
+SilcChannelKeyPayload
+silc_channel_key_payload_parse(const unsigned char *payload,
+ uint32 payload_len)
{
+ SilcBufferStruct buffer;
SilcChannelKeyPayload new;
int ret;
SILC_LOG_DEBUG(("Parsing channel key payload"));
+ silc_buffer_set(&buffer, (unsigned char *)payload, payload_len);
new = silc_calloc(1, sizeof(*new));
/* Parse the Channel Key Payload */
ret =
- silc_buffer_unformat(buffer,
+ silc_buffer_unformat(&buffer,
SILC_STR_UI16_NSTRING_ALLOC(&new->id, &new->id_len),
SILC_STR_UI16_NSTRING_ALLOC(&new->cipher,
&new->cipher_len),
to add channel key payload into a packet. */
SilcBuffer silc_channel_key_payload_encode(uint16 id_len,
- unsigned char *id,
+ const unsigned char *id,
uint16 cipher_len,
- unsigned char *cipher,
+ const unsigned char *cipher,
uint16 key_len,
- unsigned char *key)
+ const unsigned char *key)
{
SilcBuffer buffer;
uint32 len;
return buffer;
}
-/* Free's Channel Key Payload */
+/* Frees Channel Key Payload */
void silc_channel_key_payload_free(SilcChannelKeyPayload payload)
{
projects / silc.git / blobdiff