Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
- Copyright (C) 1997 - 2000 Pekka Riikonen
+ Copyright (C) 1997 - 2001 Pekka Riikonen
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
int silc_packet_send(SilcSocketConnection sock, int force_send)
{
+ SILC_LOG_DEBUG(("Sending packet to %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")));
+
/* Send now if forced to do so */
if (force_send == TRUE) {
int ret;
cannot be used. */
void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac,
- SilcBuffer buffer, unsigned int len)
+ SilcBuffer buffer, uint32 len)
{
unsigned char mac[32];
-
- if (cipher) {
- SILC_LOG_DEBUG(("Encrypting packet, cipher %s, len %d (%d)",
- cipher->cipher->name, len, len - 2));
- }
+ uint32 mac_len;
/* Compute HMAC. This assumes that HMAC is created from the entire
data area thus this uses the length found in buffer, not the length
sent as argument. */
if (hmac) {
- silc_hmac_make(hmac, buffer->data, buffer->len, mac);
- silc_buffer_put_tail(buffer, mac, hmac->hash->hash->hash_len);
+ silc_hmac_make(hmac, buffer->data, buffer->len, 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. */
- if (cipher)
+ 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);
+ }
/* Pull the HMAC into the visible data area in the buffer */
if (hmac)
- silc_buffer_pull_tail(buffer, hmac->hash->hash->hash_len);
+ silc_buffer_pull_tail(buffer, mac_len);
}
/* Assembles a new packet to be ready for send out. The buffer sent as
Packet construct is as follows (* = won't be encrypted):
- x bytes SILC Header
+ n bytes SILC Header
2 bytes Payload length (*)
1 byte Flags
1 byte Packet type
- 1 byte Source ID Type
2 bytes Source ID Length
- x bytes Source ID
- 1 byte Destination ID Type
2 bytes Destination ID Length
- x bytes Destination ID
+ 1 byte Source ID Type
+ n bytes Source ID
+ 1 byte Destination ID Type
+ n bytes Destination ID
1 - 16 bytes Padding
- x bytes Data payload
+ n bytes Data payload
All fields in the packet will be authenticated by MAC. The MAC is
- not computed here, it must be computed differently before encrypting
+ not computed here, it must be computed separately before encrypting
the packet.
*/
/* Get random padding */
#if 1
- for (i = 0; i < ctx->padlen; i++)
- tmppad[i] = silc_rng_get_byte(ctx->rng);
+ for (i = 0; i < ctx->padlen; i++) tmppad[i] = silc_rng_global_get_byte();
#else
/* XXX: For testing - to be removed */
memset(tmppad, 65, sizeof(tmppad));
outgoing buffer in SilcSocketConnection object. */
void silc_packet_send_prepare(SilcSocketConnection sock,
- unsigned int header_len,
- unsigned int padlen,
- unsigned int data_len)
+ uint32 header_len,
+ uint32 padlen,
+ uint32 data_len)
{
int totlen, oldlen;
/* There is some pending data in the buffer. */
/* Allocate more space if needed */
- if ((sock->outbuf->end - sock->outbuf->tail) < data_len) {
+ if ((sock->outbuf->end - sock->outbuf->tail) <
+ (totlen + 20)) {
SILC_LOG_DEBUG(("Reallocating outgoing data buffer"));
sock->outbuf = silc_buffer_realloc(sock->outbuf,
- sock->outbuf->truelen + totlen);
+ sock->outbuf->truelen +
+ (totlen * 2));
}
oldlen = sock->outbuf->len;
} else {
/* Buffer is free for use */
silc_buffer_clear(sock->outbuf);
+
+ /* Allocate more space if needed */
+ if ((sock->outbuf->end - sock->outbuf->tail) < (totlen + 20)) {
+ SILC_LOG_DEBUG(("Reallocating outgoing data buffer"));
+ sock->outbuf = silc_buffer_realloc(sock->outbuf,
+ sock->outbuf->truelen +
+ (totlen * 2));
+ }
+
silc_buffer_pull_tail(sock->outbuf, totlen);
silc_buffer_pull(sock->outbuf, header_len + padlen);
}
This returns amount of bytes read or -1 on error or -2 on case where
all of the data could not be read at once. */
-int silc_packet_read(int sock, SilcBuffer dest)
+int silc_packet_read(int fd, SilcSocketConnection sock)
{
int len = 0;
unsigned char buf[SILC_PACKET_READ_SIZE];
- SILC_LOG_DEBUG(("Reading data from socket %d", sock));
+ SILC_LOG_DEBUG(("Reading data from socket %d", fd));
/* Read the data from the socket. */
- len = read(sock, buf, sizeof(buf));
+ len = read(fd, buf, sizeof(buf));
if (len < 0) {
if (errno == EAGAIN || errno == EINTR) {
SILC_LOG_DEBUG(("Could not read immediately, will do it later"));
return -2;
}
- SILC_LOG_ERROR(("Cannot read from socket: %d", strerror(errno)));
+ SILC_LOG_ERROR(("Cannot read from socket: %d:%s", fd, strerror(errno)));
return -1;
}
if (!len)
return 0;
- /* Insert the data to the buffer. If the data doesn't fit to the
- buffer space is allocated for the buffer. */
- /* XXX: This may actually be bad thing as if there is pending data in
- the buffer they will be lost! */
- if (dest) {
-
- /* If the data doesn't fit we just have to allocate a whole new
- data area */
- if (dest->truelen <= len) {
-
- /* Free the old buffer */
- memset(dest->head, 'F', dest->truelen);
- silc_free(dest->head);
-
- /* Allocate new data area */
- len += SILC_PACKET_DEFAULT_SIZE;
- dest->data = silc_calloc(len, sizeof(char));
- dest->truelen = len;
- dest->len = 0;
- dest->head = dest->data;
- dest->data = dest->data;
- dest->tail = dest->data;
- dest->end = dest->data + dest->truelen;
- len -= SILC_PACKET_DEFAULT_SIZE;
- }
+ /* Insert the data to the buffer. */
- silc_buffer_put_tail(dest, buf, len);
- silc_buffer_pull_tail(dest, len);
- }
+ if (!sock->inbuf)
+ sock->inbuf = silc_buffer_alloc(SILC_PACKET_DEFAULT_SIZE);
+
+ /* If the data does not fit to the buffer reallocate it */
+ if ((sock->inbuf->end - sock->inbuf->tail) < len)
+ sock->inbuf = silc_buffer_realloc(sock->inbuf, sock->inbuf->truelen +
+ (len * 2));
+ silc_buffer_put_tail(sock->inbuf, buf, len);
+ silc_buffer_pull_tail(sock->inbuf, len);
SILC_LOG_DEBUG(("Read %d bytes", len));
return;
if (hmac)
- mac_len = hmac->hash->hash->hash_len;
+ mac_len = hmac->hmac->len;
/* Parse the packets from the data */
count = 0;
if (packetlen < SILC_PACKET_MIN_LEN) {
SILC_LOG_DEBUG(("Received invalid packet, dropped"));
+ silc_buffer_clear(sock->inbuf);
return;
}
}
parse_ctx = silc_calloc(1, sizeof(*parse_ctx));
- parse_ctx->packet = silc_calloc(1, sizeof(*parse_ctx->packet));
+ parse_ctx->packet = silc_packet_context_alloc();
parse_ctx->packet->buffer = silc_buffer_alloc(paddedlen + mac_len);
parse_ctx->sock = sock;
- parse_ctx->cipher = cipher;
- parse_ctx->hmac = hmac;
parse_ctx->context = context;
silc_buffer_pull_tail(parse_ctx->packet->buffer,
silc_buffer_pull(sock->inbuf, mac_len);
}
+ SILC_LOG_DEBUG(("Clearing inbound buffer"));
silc_buffer_clear(sock->inbuf);
}
{
int ret;
- /* Allocate the incoming data buffer if not done already. */
- if (!sock->inbuf)
- sock->inbuf = silc_buffer_alloc(SILC_PACKET_DEFAULT_SIZE);
-
- /* Read some data from connection */
- ret = silc_packet_read(sock->sock, sock->inbuf);
+ 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")));
- /* Error */
- if (ret == -1) {
- SILC_LOG_ERROR(("Error reading packet, dropped"));
- }
+ /* Read some data from connection */
+ ret = silc_packet_read(sock->sock, sock);
return ret;
}
/* Check MAC */
if (hmac) {
unsigned char mac[32];
+ uint32 mac_len;
SILC_LOG_DEBUG(("Verifying MAC"));
/* Compute HMAC of packet */
memset(mac, 0, sizeof(mac));
- silc_hmac_make(hmac, buffer->data, buffer->len, mac);
+ silc_hmac_make(hmac, buffer->data, buffer->len, mac, &mac_len);
/* Compare the HMAC's (buffer->tail has the packet's HMAC) */
- if (memcmp(mac, buffer->tail, hmac->hash->hash->hash_len)) {
- SILC_LOG_DEBUG(("MAC failed"));
+ if (memcmp(mac, buffer->tail, mac_len)) {
+ SILC_LOG_ERROR(("MAC failed"));
return FALSE;
}
/* Pull MAC from packet before decryption */
if (hmac) {
- if ((buffer->len - hmac->hash->hash->hash_len) > SILC_PACKET_MIN_LEN) {
- silc_buffer_push_tail(buffer, hmac->hash->hash->hash_len);
+ if ((buffer->len - hmac->hmac->len) > SILC_PACKET_MIN_LEN) {
+ silc_buffer_push_tail(buffer, hmac->hmac->len);
} else {
SILC_LOG_DEBUG(("Bad MAC length in packet, packet dropped"));
return FALSE;
{
/* Decrypt rest of the header plus padding */
if (cipher) {
- unsigned short truelen, len1, len2, padlen;
+ uint16 truelen, len1, len2, padlen;
/* Pull MAC from packet before decryption */
if (hmac) {
- if ((buffer->len - hmac->hash->hash->hash_len) > SILC_PACKET_MIN_LEN) {
- silc_buffer_push_tail(buffer, hmac->hash->hash->hash_len);
+ if ((buffer->len - hmac->hmac->len) > SILC_PACKET_MIN_LEN) {
+ silc_buffer_push_tail(buffer, hmac->hmac->len);
} else {
SILC_LOG_DEBUG(("Bad MAC length in packet, packet dropped"));
return FALSE;
the HMAC of the packet. If any other special or customized decryption
processing is required this function cannot be used. This returns
-1 on error, 0 when packet is normal packet and 1 when the packet
- is special and requires special processing. */
+ is special and requires special processing.
+
+ The `check_packet' is a callback funtion that this function will
+ call. The callback relates to the checking whether the packet is
+ normal packet or special packet and how it should be processed. If
+ 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)
+ SilcBuffer buffer, SilcPacketContext *packet,
+ SilcPacketCheckDecrypt check_packet,
+ void *context)
{
-#if 0
- SILC_LOG_DEBUG(("Decrypting packet, cipher %s, len %d (%d)",
- cipher->cipher->name, len, len - 2));
-#endif
+ int check;
/* Decrypt start of the packet header */
if (cipher)
- cipher->cipher->decrypt(cipher->context, buffer->data + 2,
- buffer->data + 2, SILC_PACKET_MIN_HEADER_LEN - 2,
- cipher->iv);
+ 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 ((buffer->data[3] == SILC_PACKET_PRIVATE_MESSAGE &&
- !(buffer->data[2] & SILC_PACKET_FLAG_PRIVMSG_KEY)) ||
- buffer->data[3] != SILC_PACKET_CHANNEL_MESSAGE) {
-
+ if (check == 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))
- return FALSE;
+ return -1;
return 0;
} else {
/* Packet requires special handling, decrypt rest of the header.
This only decrypts. */
- silc_packet_decrypt_rest_special(cipher, hmac, buffer);
+ if (!silc_packet_decrypt_rest_special(cipher, hmac, buffer))
+ return -1;
/* Check MAC */
if (!silc_packet_check_mac(hmac, buffer))
- return FALSE;
+ return -1;
return 1;
}
SilcPacketType silc_packet_parse(SilcPacketContext *ctx)
{
SilcBuffer buffer = ctx->buffer;
- int len;
+ int len, ret;
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)
+ return SILC_PACKET_NONE;
if (ctx->src_id_len > SILC_PACKET_MAX_ID_LEN ||
ctx->dst_id_len > SILC_PACKET_MAX_ID_LEN) {
ctx->padlen = SILC_PACKET_PADLEN(ctx->truelen);
silc_buffer_pull(buffer, len);
- silc_buffer_unformat(buffer,
- SILC_STR_UI_XNSTRING_ALLOC(&ctx->src_id,
- ctx->src_id_len),
- SILC_STR_UI_CHAR(&ctx->dst_id_type),
- SILC_STR_UI_XNSTRING_ALLOC(&ctx->dst_id,
- ctx->dst_id_len),
- SILC_STR_UI_XNSTRING(NULL, ctx->padlen),
- SILC_STR_END);
+ ret = silc_buffer_unformat(buffer,
+ SILC_STR_UI_XNSTRING_ALLOC(&ctx->src_id,
+ ctx->src_id_len),
+ SILC_STR_UI_CHAR(&ctx->dst_id_type),
+ SILC_STR_UI_XNSTRING_ALLOC(&ctx->dst_id,
+ ctx->dst_id_len),
+ SILC_STR_UI_XNSTRING(NULL, ctx->padlen),
+ SILC_STR_END);
+ if (ret == -1)
+ return SILC_PACKET_NONE;
+
silc_buffer_push(buffer, len);
SILC_LOG_HEXDUMP(("parsed packet, len %d", ctx->buffer->len),
SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx)
{
SilcBuffer buffer = ctx->buffer;
- int len, tmplen;
+ int len, tmplen, ret;
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)
+ return SILC_PACKET_NONE;
if (ctx->src_id_len > SILC_PACKET_MAX_ID_LEN ||
ctx->dst_id_len > SILC_PACKET_MAX_ID_LEN) {
ctx->padlen = SILC_PACKET_PADLEN(tmplen);
silc_buffer_pull(buffer, len);
- silc_buffer_unformat(buffer,
- SILC_STR_UI_XNSTRING_ALLOC(&ctx->src_id,
- ctx->src_id_len),
- SILC_STR_UI_CHAR(&ctx->dst_id_type),
- SILC_STR_UI_XNSTRING_ALLOC(&ctx->dst_id,
- ctx->dst_id_len),
- SILC_STR_UI_XNSTRING(NULL, ctx->padlen),
- SILC_STR_END);
+ ret = silc_buffer_unformat(buffer,
+ SILC_STR_UI_XNSTRING_ALLOC(&ctx->src_id,
+ ctx->src_id_len),
+ SILC_STR_UI_CHAR(&ctx->dst_id_type),
+ SILC_STR_UI_XNSTRING_ALLOC(&ctx->dst_id,
+ ctx->dst_id_len),
+ SILC_STR_UI_XNSTRING(NULL, ctx->padlen),
+ SILC_STR_END);
+ if (ret == -1)
+ return SILC_PACKET_NONE;
+
silc_buffer_push(buffer, len);
SILC_LOG_HEXDUMP(("parsed packet, len %d", ctx->buffer->len),
return ctx->type;
}
+
+/* Allocate packet context */
+
+SilcPacketContext *silc_packet_context_alloc()
+{
+ SilcPacketContext *ctx = silc_calloc(1, sizeof(*ctx));
+ ctx->users++;
+ return ctx;
+}
+
+/* Increse the reference count of the packet context. */
+
+SilcPacketContext *silc_packet_context_dup(SilcPacketContext *ctx)
+{
+ ctx->users++;
+ SILC_LOG_DEBUG(("Packet context %p refcnt %d->%d", ctx, ctx->users - 1,
+ ctx->users));
+ return ctx;
+}
+
+/* Decrese the reference count of the packet context and free it only if
+ it is zero. */
+
+void silc_packet_context_free(SilcPacketContext *ctx)
+{
+ ctx->users--;
+ SILC_LOG_DEBUG(("Packet context %p refcnt %d->%d", ctx, ctx->users + 1,
+ ctx->users));
+ if (ctx->users < 1)
+ {
+ if (ctx->buffer)
+ silc_buffer_free(ctx->buffer);
+ if (ctx->src_id)
+ silc_free(ctx->src_id);
+ if (ctx->dst_id)
+ silc_free(ctx->dst_id);
+ silc_free(ctx);
+ }
+}
projects / silc.git / blobdiff