SilcUInt8 refcnt; /* Reference counter */
unsigned int is_router : 1; /* Set if router stream */
unsigned int destroyed : 1; /* Set if destroyed */
+ unsigned int iv_included : 1; /* Set if IV included */
};
/* Initial size of stream buffers */
/* Header length without source and destination ID's. */
#define SILC_PACKET_HEADER_LEN 10
-/* Minimum length of SILC Packet Header. This much is decrypted always
- when packet is received to be able to get all the relevant data out
- from the header. */
+/* Minimum length of SILC Packet Header. */
#define SILC_PACKET_MIN_HEADER_LEN 16
+#define SILC_PACKET_MIN_HEADER_LEN_IV 32
/* Maximum padding length */
#define SILC_PACKET_MAX_PADLEN 128
/* Minimum packet length */
#define SILC_PACKET_MIN_LEN (SILC_PACKET_HEADER_LEN + 1)
-
-/* Macros */
-
/* Returns true length of the packet. */
#define SILC_PACKET_LENGTH(__packetdata, __ret_truelen, __ret_paddedlen) \
do { \
stream->is_router = TRUE;
}
+/* Mark to include IV in ciphertext */
+
+void silc_packet_stream_set_iv_included(SilcPacketStream stream)
+{
+ stream->iv_included = TRUE;
+}
/* Links `callbacks' to `stream' for specified packet types */
SilcCipher cipher,
SilcHmac hmac)
{
- unsigned char tmppad[SILC_PACKET_MAX_PADLEN];
+ unsigned char tmppad[SILC_PACKET_MAX_PADLEN], iv[32], psn[4];
int block_len = (cipher ? silc_cipher_get_block_len(cipher) : 0);
- int i, enclen, truelen, padlen;
+ int i, enclen, truelen, padlen, ivlen = 0, psnlen = 0;
SilcBufferStruct packet;
SILC_LOG_DEBUG(("Sending packet %s (%d) flags %d, src %d dst %d,"
enclen = truelen = (data_len + SILC_PACKET_HEADER_LEN +
src_id_len + dst_id_len);
+ /* If IV is included, the IV and sequence number is added to packet */
+ if (stream->iv_included && cipher) {
+ ivlen = block_len;
+ psnlen = sizeof(psn);
+ memcpy(iv, silc_cipher_get_iv(cipher), block_len);
+ }
+
/* We automatically figure out the packet structure from the packet
type and flags, and calculate correct length. Private messages with
private keys and channel messages are special packets as their
type == SILC_PACKET_CHANNEL_MESSAGE) {
/* Padding is calculated from header + IDs */
- SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN +
- src_id_len +
- dst_id_len), block_len, padlen);
+ SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
+ psnlen), block_len, padlen);
/* Length to encrypt, header + IDs + padding. */
- enclen = SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len + padlen;
+ enclen = (SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
+ padlen + psnlen);
} else {
/* Padding is calculated from true length of the packet */
if (flags & SILC_PACKET_FLAG_LONG_PAD)
- SILC_PACKET_PADLEN_MAX(truelen, block_len, padlen);
+ SILC_PACKET_PADLEN_MAX(truelen + psnlen, block_len, padlen);
else
- SILC_PACKET_PADLEN(truelen, block_len, padlen);
+ SILC_PACKET_PADLEN(truelen + psnlen, block_len, padlen);
- enclen += padlen;
+ enclen += padlen + psnlen;
}
/* Remove implementation specific flags */
silc_mutex_lock(stream->lock);
/* Get packet pointer from the outgoing buffer */
- if (!silc_packet_send_prepare(stream, truelen + padlen, hmac, &packet)) {
+ if (!silc_packet_send_prepare(stream, truelen + padlen + ivlen + psnlen,
+ hmac, &packet)) {
silc_mutex_unlock(stream->lock);
return FALSE;
}
+ SILC_PUT32_MSB(stream->send_psn, psn);
+
/* Create the packet. This creates the SILC header, adds padding, and
the actual packet data. */
i = silc_buffer_format(&packet,
+ SILC_STR_UI_XNSTRING(iv, ivlen),
+ SILC_STR_UI_XNSTRING(psn, psnlen),
SILC_STR_UI_SHORT(truelen),
SILC_STR_UI_CHAR(flags),
SILC_STR_UI_CHAR(type),
}
SILC_LOG_HEXDUMP(("Assembled packet, len %d", silc_buffer_len(&packet)),
- packet.data, silc_buffer_len(&packet));
+ silc_buffer_data(&packet), silc_buffer_len(&packet));
/* Encrypt the packet */
if (cipher) {
SILC_LOG_DEBUG(("Encrypting packet"));
- if (!silc_cipher_encrypt(cipher, packet.data, packet.data,
- enclen, NULL)) {
+ if (!silc_cipher_encrypt(cipher, packet.data + ivlen,
+ packet.data + ivlen, enclen, NULL)) {
SILC_LOG_ERROR(("Packet encryption failed"));
silc_mutex_unlock(stream->lock);
return FALSE;
/* Compute HMAC */
if (hmac) {
- unsigned char psn[4];
SilcUInt32 mac_len;
/* MAC is computed from the entire encrypted packet data, and put
to the end of the packet. */
silc_hmac_init(hmac);
- SILC_PUT32_MSB(stream->send_psn, psn);
- silc_hmac_update(hmac, psn, 4);
+ silc_hmac_update(hmac, psn, sizeof(psn));
silc_hmac_update(hmac, packet.data, silc_buffer_len(&packet));
silc_hmac_final(hmac, packet.tail, &mac_len);
silc_buffer_pull_tail(&packet, mac_len);
const unsigned char *data,
SilcUInt32 data_len,
const unsigned char *packet_mac,
+ const unsigned char *packet_seq,
SilcUInt32 sequence)
{
/* Check MAC */
/* Compute HMAC of packet */
silc_hmac_init(hmac);
- SILC_PUT32_MSB(sequence, psn);
- silc_hmac_update(hmac, psn, 4);
+
+ if (!packet_seq) {
+ SILC_PUT32_MSB(sequence, psn);
+ silc_hmac_update(hmac, psn, 4);
+ } else
+ silc_hmac_update(hmac, packet_seq, 4);
+
silc_hmac_update(hmac, data, data_len);
silc_hmac_final(hmac, mac, &mac_len);
{
SilcPacket packet;
SilcUInt16 packetlen;
- SilcUInt32 paddedlen, mac_len, block_len;
+ SilcUInt32 paddedlen, mac_len, block_len, ivlen, psnlen;
unsigned char tmp[SILC_PACKET_MIN_HEADER_LEN], *header;
- unsigned char iv[SILC_CIPHER_MAX_IV_SIZE];
+ unsigned char iv[SILC_CIPHER_MAX_IV_SIZE], *packet_seq = NULL;
SilcBool normal = TRUE;
int ret;
/* Parse the packets from the data */
while (silc_buffer_len(&stream->inbuf) > 0) {
+ ivlen = psnlen = 0;
- if (silc_buffer_len(&stream->inbuf) < SILC_PACKET_MIN_HEADER_LEN) {
+ if (silc_buffer_len(&stream->inbuf) <
+ stream->iv_included ? SILC_PACKET_MIN_HEADER_LEN :
+ SILC_PACKET_MIN_HEADER_LEN_IV) {
SILC_LOG_DEBUG(("Partial packet in queue, waiting for the rest"));
return;
}
/* Decrypt first block of the packet to get the length field out */
if (stream->receive_key) {
block_len = silc_cipher_get_block_len(stream->receive_key);
- memcpy(iv, silc_cipher_get_iv(stream->receive_key), block_len);
- silc_cipher_decrypt(stream->receive_key, stream->inbuf.data,
+
+ if (stream->iv_included) {
+ /* IV is included in the ciphertext */
+ memcpy(iv, stream->inbuf.data, block_len);
+ ivlen = block_len;
+ psnlen = 4;
+ } else
+ memcpy(iv, silc_cipher_get_iv(stream->receive_key), block_len);
+
+ silc_cipher_decrypt(stream->receive_key, stream->inbuf.data + ivlen,
tmp, block_len, iv);
+
header = tmp;
+ if (stream->iv_included) {
+ /* Take sequence number from packet */
+ packet_seq = header;
+ header += 4;
+ }
} else {
block_len = SILC_PACKET_MIN_HEADER_LEN;
header = stream->inbuf.data;
return;
}
- if (silc_buffer_len(&stream->inbuf) < paddedlen + mac_len) {
+ if (silc_buffer_len(&stream->inbuf) < paddedlen + ivlen + mac_len) {
SILC_LOG_DEBUG(("Received partial packet, waiting for the rest "
"(%d bytes)",
paddedlen + mac_len - silc_buffer_len(&stream->inbuf)));
/* Check MAC of the packet */
if (!silc_packet_check_mac(stream->receive_hmac, stream->inbuf.data,
- paddedlen, stream->inbuf.data + paddedlen,
- stream->receive_psn)) {
+ paddedlen + ivlen,
+ stream->inbuf.data + ivlen + paddedlen,
+ packet_seq, stream->receive_psn)) {
silc_mutex_unlock(stream->lock);
SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MAC_FAILED);
silc_mutex_lock(stream->lock);
}
SILC_LOG_HEXDUMP(("Incoming packet (%d) len %d",
- stream->receive_psn, paddedlen + mac_len),
- stream->inbuf.data, paddedlen + mac_len);
+ stream->receive_psn, paddedlen + ivlen + mac_len),
+ stream->inbuf.data, paddedlen + ivlen + mac_len);
/* Put the decrypted part, and rest of the encrypted data, and decrypt */
silc_buffer_pull_tail(&packet->buffer, paddedlen);
- silc_buffer_put(&packet->buffer, header, block_len);
- silc_buffer_pull(&packet->buffer, block_len);
- silc_buffer_put(&packet->buffer, stream->inbuf.data + block_len,
- paddedlen - block_len);
+ silc_buffer_put(&packet->buffer, header, block_len - psnlen);
+ silc_buffer_pull(&packet->buffer, block_len - psnlen);
+ silc_buffer_put(&packet->buffer, (stream->inbuf.data + ivlen +
+ psnlen + (block_len - psnlen)),
+ paddedlen - ivlen - psnlen - (block_len - psnlen));
if (stream->receive_key) {
silc_cipher_set_iv(stream->receive_key, iv);
ret = silc_packet_decrypt(stream->receive_key, stream->receive_hmac,
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