silcchannel.c
- Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+ Author: Pekka Riikonen <priikone@silcnet.org>
- Copyright (C) 1997 - 2000 Pekka Riikonen
+ Copyright (C) 1997 - 2005 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
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
+ the Free Software Foundation; version 2 of the License.
+
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
*/
-/* Channel Payload, Channel Message Payload and Channel Key Payload
- implementations. */
+/* Channel Payload and Channel Key Payload implementations. */
/* $Id$ */
-#include "silcincludes.h"
+#include "silc.h"
#include "silcchannel.h"
/******************************************************************************
/* Channel Message Payload structure. Contents of this structure is parsed
from SILC packets. */
struct SilcChannelPayloadStruct {
- unsigned short name_len;
unsigned char *channel_name;
- unsigned short id_len;
unsigned char *channel_id;
- unsigned int mode;
+ SilcUInt32 mode;
+ SilcUInt16 name_len;
+ SilcUInt16 id_len;
};
/* Parses channel payload returning new channel payload structure. */
-SilcChannelPayload silc_channel_payload_parse(SilcBuffer buffer)
+SilcChannelPayload silc_channel_payload_parse(const unsigned char *payload,
+ SilcUInt32 payload_len)
{
- SilcChannelPayload new;
+ SilcBufferStruct buffer;
+ SilcChannelPayload newp;
int ret;
SILC_LOG_DEBUG(("Parsing channel payload"));
- new = silc_calloc(1, sizeof(*new));
+ silc_buffer_set(&buffer, (unsigned char *)payload, payload_len);
+ newp = silc_calloc(1, sizeof(*newp));
+ if (!newp)
+ return NULL;
/* Parse the Channel Payload. Ignore the padding. */
- ret = silc_buffer_unformat(buffer,
- SILC_STR_UI16_NSTRING_ALLOC(&new->channel_name,
- &new->name_len),
- SILC_STR_UI16_NSTRING_ALLOC(&new->channel_id,
- &new->id_len),
- SILC_STR_UI_INT(&new->mode),
+ ret = silc_buffer_unformat(&buffer,
+ SILC_STR_UI16_NSTRING_ALLOC(&newp->channel_name,
+ &newp->name_len),
+ SILC_STR_UI16_NSTRING_ALLOC(&newp->channel_id,
+ &newp->id_len),
+ SILC_STR_UI_INT(&newp->mode),
SILC_STR_END);
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 ((newp->name_len < 1 || newp->name_len > silc_buffer_len(&buffer) - 8) ||
+ (newp->id_len < 1 || newp->id_len > silc_buffer_len(&buffer) - 8) ||
+ (newp->id_len + newp->name_len > silc_buffer_len(&buffer) - 8)) {
SILC_LOG_ERROR(("Incorrect channel payload in packet, packet dropped"));
goto err;
}
- return new;
+ return newp;
err:
- silc_channel_payload_free(new);
+ silc_channel_payload_free(newp);
return NULL;
}
/* 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,
+ SilcUInt32 payload_len)
{
+ SilcBufferStruct buffer;
SilcDList list;
- SilcChannelPayload new;
- int len, ret;
+ SilcChannelPayload newp;
+ SilcUInt32 len;
+ int ret;
SILC_LOG_DEBUG(("Parsing channel payload list"));
+ silc_buffer_set(&buffer, (unsigned char *)payload, payload_len);
list = silc_dlist_init();
- while (buffer->len) {
- new = silc_calloc(1, sizeof(*new));
- ret = silc_buffer_unformat(buffer,
- SILC_STR_UI16_NSTRING_ALLOC(&new->channel_name,
- &new->name_len),
- SILC_STR_UI16_NSTRING_ALLOC(&new->channel_id,
- &new->id_len),
- SILC_STR_UI_INT(&new->mode),
+ while (silc_buffer_len(&buffer)) {
+ newp = silc_calloc(1, sizeof(*newp));
+ if (!newp)
+ goto err;
+ ret = silc_buffer_unformat(&buffer,
+ SILC_STR_UI16_NSTRING_ALLOC(&newp->channel_name,
+ &newp->name_len),
+ SILC_STR_UI16_NSTRING_ALLOC(&newp->channel_id,
+ &newp->id_len),
+ SILC_STR_UI_INT(&newp->mode),
SILC_STR_END);
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 ((newp->name_len < 1 || newp->name_len > silc_buffer_len(&buffer) - 8) ||
+ (newp->id_len < 1 || newp->id_len > silc_buffer_len(&buffer) - 8) ||
+ (newp->id_len + newp->name_len > silc_buffer_len(&buffer) - 8)) {
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)
+ len = 2 + newp->name_len + 2 + newp->id_len + 4;
+ if (silc_buffer_len(&buffer) < len)
break;
- silc_buffer_pull(buffer, len);
+ silc_buffer_pull(&buffer, len);
- silc_dlist_add(list, new);
+ silc_dlist_add(list, newp);
}
-
+
return list;
err:
/* Encode new channel payload and returns it as buffer. */
-SilcBuffer silc_channel_payload_encode(unsigned char *channel_name,
- unsigned short channel_name_len,
- unsigned char *channel_id,
- unsigned int channel_id_len,
- unsigned int mode)
+SilcBuffer silc_channel_payload_encode(const unsigned char *channel_name,
+ SilcUInt16 channel_name_len,
+ const unsigned char *channel_id,
+ SilcUInt32 channel_id_len,
+ SilcUInt32 mode)
{
SilcBuffer buffer;
SILC_LOG_DEBUG(("Encoding message payload"));
- buffer = silc_buffer_alloc(2 + channel_name_len + 2 + channel_id_len + 4);
- silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));
+ buffer = silc_buffer_alloc_size(2 + channel_name_len + 2 +
+ channel_id_len + 4);
+ if (!buffer)
+ return NULL;
/* Encode the Channel Payload */
- silc_buffer_format(buffer,
+ silc_buffer_format(buffer,
SILC_STR_UI_SHORT(channel_name_len),
SILC_STR_UI_XNSTRING(channel_name, channel_name_len),
SILC_STR_UI_SHORT(channel_id_len),
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);
/* Return the channel name */
unsigned char *silc_channel_get_name(SilcChannelPayload payload,
- unsigned int *channel_name_len)
+ SilcUInt32 *channel_name_len)
{
if (channel_name_len)
*channel_name_len = payload->name_len;
/* Return the channel ID */
unsigned char *silc_channel_get_id(SilcChannelPayload payload,
- unsigned int *channel_id_len)
+ SilcUInt32 *channel_id_len)
{
if (channel_id_len)
*channel_id_len = payload->id_len;
/* Return the channel ID as parsed ID. */
-SilcChannelID *silc_channel_get_id_parse(SilcChannelPayload payload)
+SilcBool silc_channel_get_id_parse(SilcChannelPayload payload,
+ SilcChannelID *ret_channel_id)
{
return silc_id_str2id(payload->channel_id, payload->id_len,
- SILC_ID_CHANNEL);
+ SILC_ID_CHANNEL, ret_channel_id,
+ sizeof(SilcChannelID));
}
/* Return the mode. The mode is arbitrary. It can be the mode of the
channel or perhaps the mode of the client on the channel. The protocol
dictates what the usage of the mode is in different circumstances. */
-unsigned int silc_channel_get_mode(SilcChannelPayload payload)
+SilcUInt32 silc_channel_get_mode(SilcChannelPayload payload)
{
return payload->mode;
}
-/******************************************************************************
-
- Channel Message Payload
-
-******************************************************************************/
-
-/* Channel Message Payload structure. Contents of this structure is parsed
- from SILC packets. */
-struct SilcChannelMessagePayloadStruct {
- unsigned short data_len;
- unsigned char *data;
- unsigned char *mac;
- unsigned char *iv;
-};
-
-/* Decrypts the channel message payload. */
-
-int silc_channel_message_payload_decrypt(unsigned char *data,
- size_t data_len,
- SilcCipher cipher,
- SilcHmac hmac)
-{
- unsigned int iv_len, mac_len;
- unsigned char *end, *mac, mac2[32];
-
- /* 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. */
- end = data + data_len;
-
- /* Push the IV out of the packet */
- iv_len = silc_cipher_get_block_len(cipher);
-
- /* Decrypt the channel message */
- silc_cipher_decrypt(cipher, data, data, data_len - iv_len, (end - iv_len));
-
- /* Take the MAC */
- if (hmac) {
- mac_len = silc_hmac_len(hmac);
- mac = (end - iv_len - 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);
- if (memcmp(mac, mac2, mac_len)) {
- SILC_LOG_DEBUG(("Channel message MACs does not match"));
- return FALSE;
- }
- SILC_LOG_DEBUG(("MAC is Ok"));
- }
-
- return TRUE;
-}
-
-/* Parses channel message payload returning new channel payload structure.
- This also decrypts it and checks the MAC. */
-
-SilcChannelMessagePayload
-silc_channel_message_payload_parse(SilcBuffer buffer,
- SilcCipher cipher,
- SilcHmac hmac)
-{
- SilcChannelMessagePayload new;
- int ret;
- unsigned int iv_len, mac_len;
-
- SILC_LOG_DEBUG(("Parsing channel message payload"));
-
- /* Decrypt the payload */
- ret = silc_channel_message_payload_decrypt(buffer->data, buffer->len,
- cipher, hmac);
- if (ret == FALSE)
- return NULL;
-
- iv_len = silc_cipher_get_block_len(cipher);
- mac_len = silc_hmac_len(hmac);
-
- new = silc_calloc(1, sizeof(*new));
-
- /* Parse the Channel Message Payload. Ignore the padding. */
- ret = silc_buffer_unformat(buffer,
- SILC_STR_UI16_NSTRING_ALLOC(&new->data,
- &new->data_len),
- SILC_STR_UI16_NSTRING(NULL, NULL),
- SILC_STR_UI_XNSTRING(&new->mac, mac_len),
- SILC_STR_UI_XNSTRING(&new->iv, iv_len),
- SILC_STR_END);
- if (ret == -1)
- goto err;
-
- if (new->data_len < 1 || new->data_len > buffer->len) {
- SILC_LOG_ERROR(("Incorrect channel messaeg payload in packet, "
- "packet dropped"));
- goto err;
- }
-
- return new;
-
- err:
- silc_channel_message_payload_free(new);
- return NULL;
-}
-
-/* Encodes channel message payload into a buffer and returns it. This is used
- to add channel message payload into a packet. As the channel payload is
- encrypted separately from other parts of the packet padding must
- be applied to the payload. */
-
-SilcBuffer silc_channel_message_payload_encode(unsigned short data_len,
- unsigned char *data,
- unsigned short iv_len,
- unsigned char *iv,
- SilcCipher cipher,
- SilcHmac hmac,
- SilcRng rng)
-{
- int i;
- SilcBuffer buffer;
- unsigned int len, pad_len, mac_len;
- unsigned char pad[SILC_PACKET_MAX_PADLEN];
- unsigned char mac[32];
-
- SILC_LOG_DEBUG(("Encoding channel message payload"));
-
- /* Calculate length of padding. IV is not included into the calculation
- since it is not encrypted. */
- mac_len = silc_hmac_len(hmac);
- len = 4 + data_len + mac_len;
- pad_len = SILC_PACKET_PADLEN((len + 2));
-
- /* Allocate channel payload buffer */
- len += pad_len + iv_len;
- buffer = silc_buffer_alloc(len);
-
- /* Generate padding */
- for (i = 0; i < pad_len; i++) pad[i] = silc_rng_get_byte(rng);
-
- /* Encode the Channel Message Payload */
- silc_buffer_pull_tail(buffer, 4 + data_len + pad_len);
- silc_buffer_format(buffer,
- SILC_STR_UI_SHORT(data_len),
- SILC_STR_UI_XNSTRING(data, data_len),
- SILC_STR_UI_SHORT(pad_len),
- SILC_STR_UI_XNSTRING(pad, pad_len),
- SILC_STR_END);
-
- /* Compute the MAC of the channel message data */
- silc_hmac_make(hmac, buffer->data, buffer->len, mac, &mac_len);
-
- /* Put rest of the data to the payload */
- silc_buffer_pull_tail(buffer, mac_len + iv_len);
- silc_buffer_pull(buffer, 4 + data_len + pad_len);
- silc_buffer_format(buffer,
- SILC_STR_UI_XNSTRING(mac, mac_len),
- SILC_STR_UI_XNSTRING(iv, iv_len),
- SILC_STR_END);
- silc_buffer_push(buffer, 4 + data_len + pad_len);
-
- /* Encrypt payload of the packet. This is encrypted with the channel key. */
- silc_cipher_encrypt(cipher, buffer->data, buffer->data,
- buffer->len - iv_len, iv);
-
- memset(pad, 0, sizeof(pad));
- memset(mac, 0, sizeof(mac));
-
- return buffer;
-}
-
-/* Free's Channel Message Payload */
-
-void silc_channel_message_payload_free(SilcChannelMessagePayload payload)
-{
- if (payload->data) {
- memset(payload->data, 0, payload->data_len);
- silc_free(payload->data);
- }
- silc_free(payload);
-}
-
-/* Return data */
-
-unsigned char *silc_channel_message_get_data(SilcChannelMessagePayload payload,
- unsigned int *data_len)
-{
- if (data_len)
- *data_len = payload->data_len;
-
- return payload->data;
-}
-
-/* Return MAC. The caller knows the length of the MAC */
-
-unsigned char *silc_channel_mesage_get_mac(SilcChannelMessagePayload payload)
-{
- return payload->mac;
-}
-
-/* Return IV. The caller knows the length of the IV */
-
-unsigned char *silc_channel_message_get_iv(SilcChannelMessagePayload payload)
-{
- return payload->iv;
-}
/******************************************************************************
/* Channel Key Payload structrue. Channel keys are parsed from SILC
packets into this structure. */
struct SilcChannelKeyPayloadStruct {
- unsigned short id_len;
unsigned char *id;
- unsigned short cipher_len;
unsigned char *cipher;
- unsigned short key_len;
unsigned char *key;
+ SilcUInt16 id_len;
+ SilcUInt16 cipher_len;
+ SilcUInt16 key_len;
};
/* 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,
+ SilcUInt32 payload_len)
{
- SilcChannelKeyPayload new;
+ SilcBufferStruct buffer;
+ SilcChannelKeyPayload newp;
int ret;
SILC_LOG_DEBUG(("Parsing channel key payload"));
- new = silc_calloc(1, sizeof(*new));
+ silc_buffer_set(&buffer, (unsigned char *)payload, payload_len);
+ newp = silc_calloc(1, sizeof(*newp));
+ if (!newp)
+ return NULL;
/* Parse the Channel Key Payload */
ret =
- silc_buffer_unformat(buffer,
- SILC_STR_UI16_NSTRING_ALLOC(&new->id, &new->id_len),
- SILC_STR_UI16_NSTRING_ALLOC(&new->cipher,
- &new->cipher_len),
- SILC_STR_UI16_NSTRING_ALLOC(&new->key, &new->key_len),
+ silc_buffer_unformat(&buffer,
+ SILC_STR_UI16_NSTRING_ALLOC(&newp->id, &newp->id_len),
+ SILC_STR_UI16_NSTRING_ALLOC(&newp->cipher,
+ &newp->cipher_len),
+ SILC_STR_UI16_NSTRING_ALLOC(&newp->key,
+ &newp->key_len),
SILC_STR_END);
if (ret == -1)
goto err;
- if (new->id_len < 1 || new->key_len < 1 || new->cipher_len < 1) {
+ if (newp->id_len < 1 || newp->key_len < 1 || newp->cipher_len < 1 ||
+ newp->id_len + newp->cipher_len + newp->key_len > silc_buffer_len(&buffer) - 6) {
SILC_LOG_ERROR(("Incorrect channel key payload in packet"));
goto err;
}
- return new;
+ return newp;
err:
- if (new->id)
- silc_free(new->id);
- if (new->cipher)
- silc_free(new->cipher);
- if (new->key)
- silc_free(new->key);
- silc_free(new);
+ if (newp->id)
+ silc_free(newp->id);
+ if (newp->cipher)
+ silc_free(newp->cipher);
+ if (newp->key)
+ silc_free(newp->key);
+ silc_free(newp);
return NULL;
}
-/* Encodes channel key payload into a buffer and returns it. This is used
+/* Encodes channel key payload into a buffer and returns it. This is used
to add channel key payload into a packet. */
-SilcBuffer silc_channel_key_payload_encode(unsigned short id_len,
- unsigned char *id,
- unsigned short cipher_len,
- unsigned char *cipher,
- unsigned short key_len,
- unsigned char *key)
+SilcBuffer silc_channel_key_payload_encode(SilcUInt16 id_len,
+ const unsigned char *id,
+ SilcUInt16 cipher_len,
+ const unsigned char *cipher,
+ SilcUInt16 key_len,
+ const unsigned char *key)
{
SilcBuffer buffer;
- unsigned int len;
+ SilcUInt32 len;
SILC_LOG_DEBUG(("Encoding channel key payload"));
- /* Allocate channel payload buffer. Length is 2 + id + 2 + key +
+ /* Allocate channel payload buffer. Length is 2 + id + 2 + key +
2 + cipher */
len = 2 + id_len + 2 + key_len + 2 + cipher_len;
- buffer = silc_buffer_alloc(len);
-
- silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));
+ buffer = silc_buffer_alloc_size(len);
+ if (!buffer)
+ return NULL;
/* Encode the Channel Payload */
- silc_buffer_format(buffer,
+ silc_buffer_format(buffer,
SILC_STR_UI_SHORT(id_len),
SILC_STR_UI_XNSTRING(id, id_len),
SILC_STR_UI_SHORT(cipher_len),
return buffer;
}
-/* Free's Channel Key Payload */
+/* Frees Channel Key Payload */
void silc_channel_key_payload_free(SilcChannelKeyPayload payload)
{
if (payload) {
- if (payload->id)
- silc_free(payload->id);
- if (payload->cipher)
- silc_free(payload->cipher);
+ silc_free(payload->id);
+ silc_free(payload->cipher);
if (payload->key) {
memset(payload->key, 0, payload->key_len);
silc_free(payload->key);
/* Return ID */
-unsigned char *silc_channel_key_get_id(SilcChannelKeyPayload payload,
- unsigned int *id_len)
+unsigned char *silc_channel_key_get_id(SilcChannelKeyPayload payload,
+ SilcUInt32 *id_len)
{
if (id_len)
*id_len = payload->id_len;
/* Return cipher name */
unsigned char *silc_channel_key_get_cipher(SilcChannelKeyPayload payload,
- unsigned int *cipher_len)
+ SilcUInt32 *cipher_len)
{
if (cipher_len)
*cipher_len = payload->cipher_len;
/* Return key */
unsigned char *silc_channel_key_get_key(SilcChannelKeyPayload payload,
- unsigned int *key_len)
+ SilcUInt32 *key_len)
{
if (key_len)
*key_len = payload->key_len;
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