other process of HMAC computing and encryption is needed this function
cannot be used. */
-void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac,
+void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac, uint32 sequence,
SilcBuffer buffer, uint32 len)
{
unsigned char mac[32];
data area thus this uses the length found in buffer, not the length
sent as argument. */
if (hmac) {
+ unsigned char psn[4];
+
silc_hmac_init(hmac);
+
+ /* XXX Backwards support for old MAC computation.
+ XXX Remove in 0.7.x */
+ if (!silc_hmac_get_b(hmac)) {
+ SILC_PUT32_MSB(sequence, psn);
+ silc_hmac_update(hmac, psn, 4);
+ }
+
silc_hmac_update(hmac, buffer->data, buffer->len);
silc_hmac_final(hmac, mac, &mac_len);
silc_buffer_put_tail(buffer, mac, mac_len);
memset(mac, 0, sizeof(mac));
}
- /* Encrypt the data area of the packet. 2 bytes of the packet
- are not encrypted. */
+ /* Encrypt the data area of the packet. */
if (cipher) {
- SILC_LOG_DEBUG(("Encrypting packet, cipher %s, len %d (%d)",
- cipher->cipher->name, len, len - 2));
- cipher->cipher->encrypt(cipher->context, buffer->data + 2,
- buffer->data + 2, len - 2, cipher->iv);
+ SILC_LOG_DEBUG(("Encrypting packet, cipher %s, len %d",
+ cipher->cipher->name, len));
+ /* XXX Backwards support for 0.5.x
+ XXX Remove in 0.7.x */
+ if (hmac && silc_hmac_get_b(hmac))
+ silc_cipher_encrypt(cipher, buffer->data + 2, buffer->data + 2,
+ len - 1, cipher->iv);
+ else
+ silc_cipher_encrypt(cipher, buffer->data, buffer->data, len, cipher->iv);
}
/* Pull the HMAC into the visible data area in the buffer */
^ ^
Start of assembled packet
- Packet construct is as follows (* = won't be encrypted):
+ Packet construct is as follows:
n bytes SILC Header
- 2 bytes Payload length (*)
+ 2 bytes Payload length
1 byte Flags
1 byte Packet type
2 bytes Source ID Length
*/
-void silc_packet_assemble(SilcPacketContext *ctx)
+void silc_packet_assemble(SilcPacketContext *ctx, SilcCipher cipher)
{
unsigned char tmppad[SILC_PACKET_MAX_PADLEN];
+ int block_len = cipher ? silc_cipher_get_block_len(cipher) : 0;
int i;
SILC_LOG_DEBUG(("Assembling outgoing packet"));
ctx->src_id_len + ctx->dst_id_len;
/* Calculate the length of the padding. The padding is calculated from
- the data that will be encrypted. As protocol states 3 first bytes
- of the packet are not encrypted they are not included in the
- padding calculation. */
- if (!ctx->padlen)
- ctx->padlen = SILC_PACKET_PADLEN(ctx->truelen);
+ the data that will be encrypted. */
+ if (!ctx->padlen) {
+ ctx->padlen = SILC_PACKET_PADLEN(ctx->truelen, block_len);
+ /* XXX backwards support for 0.5.x
+ XXX remove in 0.7.x */
+ if (cipher->back)
+ ctx->padlen = SILC_PACKET_PADLEN2(ctx->truelen, block_len);
+ }
/* Put the start of the data section to the right place. */
silc_buffer_push(ctx->buffer, SILC_PACKET_HEADER_LEN +
******************************************************************************/
-/* Processes the received data. This checks the received data and
- calls parser callback that handles the actual packet decryption
- and parsing. If more than one packet was received this calls the
- parser multiple times. The parser callback will get context
- SilcPacketParserContext that includes the packet and the `context'
- sent to this function. */
+static int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
+ uint32 sequence, SilcBuffer buffer,
+ bool normal);
+
+/* Receives packet from network and reads the data into connection's
+ incoming data buffer. If the data was read directly this returns the
+ read bytes, if error occured this returns -1, if the data could not
+ be read directly at this time this returns -2 in which case the data
+ should be read again at some later time, or If EOF occured this returns
+ 0. */
+
+int silc_packet_receive(SilcSocketConnection sock)
+{
+ int ret;
+
+ SILC_LOG_DEBUG(("Receiving packet from %s:%d [%s]", sock->hostname,
+ sock->port,
+ (sock->type == SILC_SOCKET_TYPE_UNKNOWN ? "Unknown" :
+ sock->type == SILC_SOCKET_TYPE_CLIENT ? "Client" :
+ sock->type == SILC_SOCKET_TYPE_SERVER ? "Server" :
+ "Router")));
+
+ /* Read some data from connection */
+ ret = silc_socket_read(sock);
+
+ return ret;
+}
+
+/* Processes and decrypts the incmoing data, and calls parser callback
+ for each received packet that will handle the actual packet parsing.
+ If more than one packet was received this calls the parser multiple
+ times. The parser callback will get context SilcPacketParserContext
+ that includes the packet and the `parser_context' sent to this
+ function.
+
+ The `local_is_router' indicates whether the caller is router server
+ in which case the receiving process of a certain packet types may
+ be special. Normal server and client must set it to FALSE. The
+ SilcPacketParserContext will indicate also whether the received
+ packet was normal or special packet. */
void silc_packet_receive_process(SilcSocketConnection sock,
+ bool local_is_router,
SilcCipher cipher, SilcHmac hmac,
+ uint32 sequence,
SilcPacketParserCallback parser,
- void *context)
+ void *parser_context)
{
SilcPacketParserContext *parse_ctx;
- int packetlen, paddedlen, count, mac_len = 0;
+ int packetlen, paddedlen, mac_len = 0;
+ int block_len = cipher ? silc_cipher_get_block_len(cipher) : 0;
- /* We need at least 2 bytes of data to be able to start processing
- the packet. */
- if (sock->inbuf->len < 2)
+ if (sock->inbuf->len < SILC_PACKET_MIN_HEADER_LEN)
return;
if (hmac)
mac_len = silc_hmac_len(hmac);
/* Parse the packets from the data */
- count = 0;
while (sock->inbuf->len > 0) {
- SILC_PACKET_LENGTH(sock->inbuf, packetlen, paddedlen);
- paddedlen += 2;
- count++;
+ /* Decrypt first 16 bytes of the packet */
+ if (!SILC_IS_INBUF_PENDING(sock) && cipher) {
+ /* XXX backwards support for 0.5.x
+ XXX remove in 0.7.x */
+ if (cipher->back)
+ silc_cipher_decrypt(cipher, sock->inbuf->data + 2,
+ sock->inbuf->data + 2,
+ SILC_PACKET_MIN_HEADER_LEN, cipher->iv);
+ else
+ silc_cipher_decrypt(cipher, sock->inbuf->data, sock->inbuf->data,
+ SILC_PACKET_MIN_HEADER_LEN, cipher->iv);
+ }
+
+ /* Get packet lenght and full packet length with padding */
+ SILC_PACKET_LENGTH(sock->inbuf, packetlen);
+ /* XXX backwards support for 0.5.x
+ XXX remove in 0.7.x */
+ if (cipher && cipher->back) {
+ paddedlen = packetlen + SILC_PACKET_PADLEN2(packetlen, block_len);
+ paddedlen += 2;
+ } else {
+ paddedlen = packetlen + SILC_PACKET_PADLEN(packetlen, block_len);
+ }
+
+ /* Sanity checks */
if (packetlen < SILC_PACKET_MIN_LEN) {
SILC_LOG_DEBUG(("Received invalid packet, dropped"));
silc_buffer_clear(sock->inbuf);
}
if (sock->inbuf->len < paddedlen + mac_len) {
- SILC_LOG_DEBUG(("Received partial packet, waiting for the rest"));
+ SILC_LOG_DEBUG(("Received partial packet, waiting for the rest"
+ "(%d < %d)", sock->inbuf->len, paddedlen + mac_len));
+ SILC_SET_INBUF_PENDING(sock);
return;
}
+ SILC_UNSET_INBUF_PENDING(sock);
parse_ctx = silc_calloc(1, sizeof(*parse_ctx));
parse_ctx->packet = silc_packet_context_alloc();
parse_ctx->packet->buffer = silc_buffer_alloc(paddedlen + mac_len);
+ parse_ctx->packet->sequence = sequence++;
parse_ctx->sock = sock;
- parse_ctx->context = context;
+ parse_ctx->context = parser_context;
silc_buffer_pull_tail(parse_ctx->packet->buffer,
SILC_BUFFER_END(parse_ctx->packet->buffer));
silc_buffer_put(parse_ctx->packet->buffer, sock->inbuf->data,
- paddedlen + mac_len);
+ paddedlen + mac_len);
+
+ SILC_LOG_HEXDUMP(("Incoming packet (%d) (%d bytes decrypted), len %d",
+ sequence - 1, block_len, paddedlen + mac_len),
+ sock->inbuf->data, paddedlen + mac_len);
+
+ /* Check whether this is normal or special packet */
+ if (local_is_router) {
+ if (sock->inbuf->data[3] == SILC_PACKET_PRIVATE_MESSAGE &&
+ (sock->inbuf->data[2] & SILC_PACKET_FLAG_PRIVMSG_KEY))
+ parse_ctx->normal = FALSE;
+ else if (sock->inbuf->data[3] != SILC_PACKET_CHANNEL_MESSAGE ||
+ (sock->inbuf->data[3] == SILC_PACKET_CHANNEL_MESSAGE &&
+ sock->type == SILC_SOCKET_TYPE_ROUTER))
+ parse_ctx->normal = TRUE;
+ } else {
+ if (sock->inbuf->data[3] == SILC_PACKET_PRIVATE_MESSAGE &&
+ (sock->inbuf->data[2] & SILC_PACKET_FLAG_PRIVMSG_KEY))
+ parse_ctx->normal = FALSE;
+ else if (sock->inbuf->data[3] != SILC_PACKET_CHANNEL_MESSAGE)
+ parse_ctx->normal = TRUE;
+ }
- SILC_LOG_HEXDUMP(("Incoming packet, len %d",
- parse_ctx->packet->buffer->len),
- parse_ctx->packet->buffer->data,
- parse_ctx->packet->buffer->len);
+ /* Decrypt rest of the packet */
+ if (cipher)
+ silc_packet_decrypt(cipher, hmac, parse_ctx->packet->sequence,
+ parse_ctx->packet->buffer, parse_ctx->normal);
/* Call the parser */
if (parser)
- (*parser)(parse_ctx);
+ (*parser)(parse_ctx, parser_context);
/* Pull the packet from inbuf thus we'll get the next one
in the inbuf. */
- silc_buffer_pull(sock->inbuf, paddedlen);
- if (hmac)
- silc_buffer_pull(sock->inbuf, mac_len);
+ silc_buffer_pull(sock->inbuf, paddedlen + mac_len);
}
SILC_LOG_DEBUG(("Clearing inbound buffer"));
silc_buffer_clear(sock->inbuf);
}
-/* Receives packet from network and reads the data into connection's
- incoming data buffer. If the data was read directly this returns the
- read bytes, if error occured this returns -1, if the data could not
- be read directly at this time this returns -2 in which case the data
- should be read again at some later time, or If EOF occured this returns
- 0. */
-
-int silc_packet_receive(SilcSocketConnection sock)
-{
- int ret;
-
- SILC_LOG_DEBUG(("Receiving packet from %s:%d [%s]", sock->hostname,
- sock->port,
- (sock->type == SILC_SOCKET_TYPE_UNKNOWN ? "Unknown" :
- sock->type == SILC_SOCKET_TYPE_CLIENT ? "Client" :
- sock->type == SILC_SOCKET_TYPE_SERVER ? "Server" :
- "Router")));
-
- /* Read some data from connection */
- ret = silc_socket_read(sock);
-
- return ret;
-}
-
/* Checks MAC in the packet. Returns TRUE if MAC is Ok. This is called
after packet has been totally decrypted and parsed. */
-static int silc_packet_check_mac(SilcHmac hmac, SilcBuffer buffer)
+static int silc_packet_check_mac(SilcHmac hmac, SilcBuffer buffer,
+ uint32 sequence)
{
/* Check MAC */
if (hmac) {
- unsigned char mac[32];
+ unsigned char mac[32], psn[4];
uint32 mac_len;
SILC_LOG_DEBUG(("Verifying MAC"));
/* Compute HMAC of packet */
+
memset(mac, 0, sizeof(mac));
silc_hmac_init(hmac);
+
+ /* XXX Backwards support for old MAC computation.
+ XXX Remove in 0.7.x */
+ if (!silc_hmac_get_b(hmac)) {
+ SILC_PUT32_MSB(sequence, psn);
+ silc_hmac_update(hmac, psn, 4);
+ }
+
silc_hmac_update(hmac, buffer->data, buffer->len);
silc_hmac_final(hmac, mac, &mac_len);
/* Compare the HMAC's (buffer->tail has the packet's HMAC) */
if (memcmp(mac, buffer->tail, mac_len)) {
SILC_LOG_ERROR(("MAC failed"));
+ assert(FALSE);
return FALSE;
}
SILC_LOG_DEBUG(("Decrypting rest of the packet"));
/* Decrypt rest of the packet */
- silc_buffer_pull(buffer, SILC_PACKET_MIN_HEADER_LEN - 2);
- cipher->cipher->decrypt(cipher->context, buffer->data + 2,
- buffer->data + 2, buffer->len - 2,
- cipher->iv);
- silc_buffer_push(buffer, SILC_PACKET_MIN_HEADER_LEN - 2);
+ silc_buffer_pull(buffer, SILC_PACKET_MIN_HEADER_LEN);
+ /* XXX backwards support for 0.5.x
+ XXX remove in 0.7.x */
+ if (cipher->back)
+ silc_cipher_decrypt(cipher, buffer->data + 2, buffer->data + 2,
+ buffer->len - 2,
+ cipher->iv);
+ else
+ silc_cipher_decrypt(cipher, buffer->data, buffer->data, buffer->len,
+ cipher->iv);
+ silc_buffer_push(buffer, SILC_PACKET_MIN_HEADER_LEN);
SILC_LOG_HEXDUMP(("Fully decrypted packet, len %d", buffer->len),
buffer->data, buffer->len);
{
/* Decrypt rest of the header plus padding */
if (cipher) {
- uint16 truelen, len1, len2, padlen;
+ uint16 truelen, len1, len2, padlen, blocklen;
/* Pull MAC from packet before decryption */
if (hmac) {
SILC_GET16_MSB(len1, &buffer->data[4]);
SILC_GET16_MSB(len2, &buffer->data[6]);
+ blocklen = silc_cipher_get_block_len(cipher);
truelen = SILC_PACKET_HEADER_LEN + len1 + len2;
- padlen = SILC_PACKET_PADLEN(truelen);
- len1 = (truelen + padlen) - (SILC_PACKET_MIN_HEADER_LEN - 2);
- silc_buffer_pull(buffer, SILC_PACKET_MIN_HEADER_LEN - 2);
- if (len1 - 2 > buffer->len) {
- SILC_LOG_DEBUG(("Garbage in header of packet, bad packet length, "
- "packet dropped"));
- return FALSE;
- }
+ /* XXX backwards support for 0.5.x
+ XXX remove in 0.7.x */
+ if (cipher->back) {
+ padlen = SILC_PACKET_PADLEN2(truelen, blocklen);
+ len1 = (truelen + padlen) - (SILC_PACKET_MIN_HEADER_LEN);
+
+ silc_buffer_pull(buffer, SILC_PACKET_MIN_HEADER_LEN);
+
+ if (len1 - 2 > buffer->len) {
+ SILC_LOG_DEBUG(("Garbage in header of packet, bad packet length, "
+ "packet dropped"));
+ return FALSE;
+ }
- cipher->cipher->decrypt(cipher->context, buffer->data + 2,
- buffer->data + 2, len1 - 2,
- cipher->iv);
- silc_buffer_push(buffer, SILC_PACKET_MIN_HEADER_LEN - 2);
+ silc_cipher_decrypt(cipher, buffer->data + 2, buffer->data + 2,
+ len1 - 2, cipher->iv);
+ } else {
+ blocklen = silc_cipher_get_block_len(cipher);
+ truelen = SILC_PACKET_HEADER_LEN + len1 + len2;
+ padlen = SILC_PACKET_PADLEN(truelen, blocklen);
+ len1 = (truelen + padlen) - SILC_PACKET_MIN_HEADER_LEN;
+
+ silc_buffer_pull(buffer, SILC_PACKET_MIN_HEADER_LEN);
+
+ if (len1 > buffer->len) {
+ SILC_LOG_DEBUG(("Garbage in header of packet, bad packet length, "
+ "packet dropped"));
+ return FALSE;
+ }
+
+ silc_cipher_decrypt(cipher, buffer->data, buffer->data, len1, cipher->iv);
+ }
+ silc_buffer_push(buffer, SILC_PACKET_MIN_HEADER_LEN);
}
return TRUE;
the callback return TRUE the packet is normal and FALSE if the packet
is special and requires special procesing. */
-int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
- SilcBuffer buffer, SilcPacketContext *packet,
- SilcPacketCheckDecrypt check_packet,
- void *context)
+static int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
+ uint32 sequence, SilcBuffer buffer,
+ bool normal)
{
- int check;
-
- /* Decrypt start of the packet header */
- if (cipher)
- silc_cipher_decrypt(cipher, buffer->data + 2, buffer->data + 2,
- SILC_PACKET_MIN_HEADER_LEN - 2, cipher->iv);
-
- /* Do packet checking, whether the packet is normal or special */
- check = check_packet((SilcPacketType)buffer->data[3], buffer,
- packet, context);
-
/* If the packet type is not any special type lets decrypt rest
of the packet here. */
- if (check == TRUE) {
+ if (normal == TRUE) {
/* Normal packet, decrypt rest of the packet */
if (!silc_packet_decrypt_rest(cipher, hmac, buffer))
return -1;
/* Check MAC */
- if (!silc_packet_check_mac(hmac, buffer))
+ if (!silc_packet_check_mac(hmac, buffer, sequence))
return -1;
return 0;
return -1;
/* Check MAC */
- if (!silc_packet_check_mac(hmac, buffer))
+ if (!silc_packet_check_mac(hmac, buffer, sequence))
return -1;
return 1;
function returns the type of the packet. The data section of the
buffer is parsed, not head or tail sections. */
-SilcPacketType silc_packet_parse(SilcPacketContext *ctx)
+SilcPacketType silc_packet_parse(SilcPacketContext *ctx, SilcCipher cipher)
{
SilcBuffer buffer = ctx->buffer;
int len, ret;
+ int block_len = cipher ? silc_cipher_get_block_len(cipher) : 0;
SILC_LOG_DEBUG(("Parsing incoming packet"));
if (ctx->src_id_len > SILC_PACKET_MAX_ID_LEN ||
ctx->dst_id_len > SILC_PACKET_MAX_ID_LEN) {
- SILC_LOG_ERROR(("Bad ID lengths in packet"));
+ SILC_LOG_ERROR(("Bad ID lengths in packet (%d and %d)",
+ ctx->src_id_len, ctx->dst_id_len));
return SILC_PACKET_NONE;
}
/* Calculate length of padding in packet */
- ctx->padlen = SILC_PACKET_PADLEN(ctx->truelen);
+ ctx->padlen = SILC_PACKET_PADLEN(ctx->truelen, block_len);
silc_buffer_pull(buffer, len);
ret = silc_buffer_unformat(buffer,
if (ret == -1)
return SILC_PACKET_NONE;
+ /* XXX backwards support for 0.5.x
+ XXX remove in 0.7.x */
+ silc_buffer_pull(buffer,
+ ctx->src_id_len + 1 + ctx->dst_id_len + ctx->padlen);
+ SILC_LOG_DEBUG(("**************** %d", buffer->len));
+ if (buffer->len == 2)
+ ctx->padlen += 2;
+ silc_buffer_push(buffer, ret);
+
silc_buffer_push(buffer, len);
SILC_LOG_HEXDUMP(("parsed packet, len %d", ctx->buffer->len),
the header in a way that it does not take the data area into account
and parses the header and padding area only. */
-SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx)
+SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx,
+ SilcCipher cipher)
{
SilcBuffer buffer = ctx->buffer;
int len, tmplen, ret;
+ int block_len = cipher ? silc_cipher_get_block_len(cipher) : 0;
SILC_LOG_DEBUG(("Parsing incoming packet"));
SILC_STR_UI_SHORT(&ctx->dst_id_len),
SILC_STR_UI_CHAR(&ctx->src_id_type),
SILC_STR_END);
- if (len == -1)
+ if (len == -1) {
+ SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
return SILC_PACKET_NONE;
+ }
if (ctx->src_id_len > SILC_PACKET_MAX_ID_LEN ||
ctx->dst_id_len > SILC_PACKET_MAX_ID_LEN) {
- SILC_LOG_ERROR(("Bad ID lengths in packet"));
+ SILC_LOG_ERROR(("Bad ID lengths in packet (%d and %d)",
+ ctx->src_id_len, ctx->dst_id_len));
return SILC_PACKET_NONE;
}
the data area is not used in the padding calculation as it won't
be decrypted by the caller. */
tmplen = SILC_PACKET_HEADER_LEN + ctx->src_id_len + ctx->dst_id_len;
- ctx->padlen = SILC_PACKET_PADLEN(tmplen);
+ /* XXX backwards support for 0.5.x
+ XXX remove in 0.7.x */
+ if (ctx->back)
+ ctx->padlen = SILC_PACKET_PADLEN2(tmplen, block_len);
+ else
+ ctx->padlen = SILC_PACKET_PADLEN(tmplen, block_len);
silc_buffer_pull(buffer, len);
ret = silc_buffer_unformat(buffer,
ctx->dst_id_len),
SILC_STR_UI_XNSTRING(NULL, ctx->padlen),
SILC_STR_END);
- if (ret == -1)
+ if (ret == -1) {
+ SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
return SILC_PACKET_NONE;
+ }
silc_buffer_push(buffer, len);
projects / silc.git / blobdiff