+++ /dev/null
-/*
-
- payload.c
-
- Author: Pekka Riikonen <priikone@silcnet.org>
-
- Copyright (C) 2000 - 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; 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.
-
-*/
-/* $Id$ */
-
-#include "silc.h"
-#include "silcske_i.h"
-
-/* Encodes Key Exchange Start Payload into a SILC Buffer to be sent
- to the other end. */
-
-SilcSKEStatus silc_ske_payload_start_encode(SilcSKE ske,
- SilcSKEStartPayload payload,
- SilcBuffer *return_buffer)
-{
- SilcBuffer buf;
- int ret;
-
- SILC_LOG_DEBUG(("Encoding KE Start Payload"));
-
- if (!payload)
- return SILC_SKE_STATUS_ERROR;
-
- buf = silc_buffer_alloc_size(payload->len);
- if (!buf)
- return SILC_SKE_STATUS_OUT_OF_MEMORY;
-
- /* Encode the payload */
- ret = silc_buffer_format(buf,
- SILC_STR_UI_CHAR(0), /* RESERVED field */
- SILC_STR_UI_CHAR(payload->flags),
- SILC_STR_UI_SHORT(payload->len),
- SILC_STR_UI_XNSTRING(payload->cookie,
- payload->cookie_len),
- SILC_STR_UI_SHORT(payload->version_len),
- SILC_STR_UI_XNSTRING(payload->version,
- payload->version_len),
- SILC_STR_UI_SHORT(payload->ke_grp_len),
- SILC_STR_UI_XNSTRING(payload->ke_grp_list,
- payload->ke_grp_len),
- SILC_STR_UI_SHORT(payload->pkcs_alg_len),
- SILC_STR_UI_XNSTRING(payload->pkcs_alg_list,
- payload->pkcs_alg_len),
- SILC_STR_UI_SHORT(payload->enc_alg_len),
- SILC_STR_UI_XNSTRING(payload->enc_alg_list,
- payload->enc_alg_len),
- SILC_STR_UI_SHORT(payload->hash_alg_len),
- SILC_STR_UI_XNSTRING(payload->hash_alg_list,
- payload->hash_alg_len),
- SILC_STR_UI_SHORT(payload->hmac_alg_len),
- SILC_STR_UI_XNSTRING(payload->hmac_alg_list,
- payload->hmac_alg_len),
- SILC_STR_UI_SHORT(payload->comp_alg_len),
- SILC_STR_UI_XNSTRING(payload->comp_alg_list,
- payload->comp_alg_len),
- SILC_STR_END);
- if (ret == -1) {
- silc_buffer_free(buf);
- return SILC_SKE_STATUS_ERROR;
- }
-
- /* Return the encoded buffer */
- *return_buffer = buf;
-
- SILC_LOG_HEXDUMP(("KE Start Payload"), buf->data, silc_buffer_len(buf));
-
- return SILC_SKE_STATUS_OK;
-}
-
-/* Parses the Key Exchange Start Payload. Parsed data is returned
- to allocated payload structure. */
-
-SilcSKEStatus
-silc_ske_payload_start_decode(SilcSKE ske,
- SilcBuffer buffer,
- SilcSKEStartPayload *return_payload)
-{
- SilcSKEStartPayload payload;
- SilcSKEStatus status = SILC_SKE_STATUS_ERROR;
- unsigned char tmp;
- int ret;
-
- SILC_LOG_DEBUG(("Decoding Key Exchange Start Payload"));
-
- SILC_LOG_HEXDUMP(("KE Start Payload"), buffer->data,
- silc_buffer_len(buffer));
-
- payload = silc_calloc(1, sizeof(*payload));
- if (!payload)
- return SILC_SKE_STATUS_OUT_OF_MEMORY;
- payload->cookie_len = SILC_SKE_COOKIE_LEN;
-
- /* Parse start of the payload */
- ret =
- silc_buffer_unformat(buffer,
- SILC_STR_UI_CHAR(&tmp), /* RESERVED Field */
- SILC_STR_UI_CHAR(&payload->flags),
- SILC_STR_UI_SHORT(&payload->len),
- SILC_STR_UI_XNSTRING_ALLOC(&payload->cookie,
- payload->cookie_len),
- SILC_STR_UI16_NSTRING_ALLOC(&payload->version,
- &payload->version_len),
- SILC_STR_UI16_NSTRING_ALLOC(&payload->ke_grp_list,
- &payload->ke_grp_len),
- SILC_STR_UI16_NSTRING_ALLOC(&payload->pkcs_alg_list,
- &payload->pkcs_alg_len),
- SILC_STR_UI16_NSTRING_ALLOC(&payload->enc_alg_list,
- &payload->enc_alg_len),
- SILC_STR_UI16_NSTRING_ALLOC(&payload->hash_alg_list,
- &payload->hash_alg_len),
- SILC_STR_UI16_NSTRING_ALLOC(&payload->hmac_alg_list,
- &payload->hmac_alg_len),
- SILC_STR_UI16_NSTRING_ALLOC(&payload->comp_alg_list,
- &payload->comp_alg_len),
- SILC_STR_END);
- if (ret == -1) {
- SILC_LOG_ERROR(("Malformed KE Start Payload"));
- status = SILC_SKE_STATUS_BAD_PAYLOAD;
- goto err;
- }
-
- if (tmp != 0) {
- SILC_LOG_ERROR(("Bad RESERVED field in KE Start Payload"));
- status = SILC_SKE_STATUS_BAD_RESERVED_FIELD;
- goto err;
- }
-
- if (payload->len != silc_buffer_len(buffer)) {
- SILC_LOG_ERROR(("Garbage after KE Start Payload"));
- status = SILC_SKE_STATUS_BAD_PAYLOAD_LENGTH;
- goto err;
- }
-
- /* Check for mandatory fields */
- if (!payload->cookie || !payload->version_len ||
- !payload->ke_grp_len || !payload->pkcs_alg_len ||
- !payload->enc_alg_len || !payload->hash_alg_len ||
- !payload->hmac_alg_len) {
- SILC_LOG_ERROR(("KE Start Payload is missing mandatory fields"));
- status = SILC_SKE_STATUS_BAD_PAYLOAD;
- goto err;
- }
-
- /* Return the payload */
- *return_payload = payload;
-
- return SILC_SKE_STATUS_OK;
-
- err:
- silc_ske_payload_start_free(payload);
-
- ske->status = status;
- return status;
-}
-
-/* Free's Start Payload */
-
-void silc_ske_payload_start_free(SilcSKEStartPayload payload)
-{
- if (payload) {
- silc_free(payload->cookie);
- silc_free(payload->version);
- silc_free(payload->ke_grp_list);
- silc_free(payload->pkcs_alg_list);
- silc_free(payload->enc_alg_list);
- silc_free(payload->hash_alg_list);
- silc_free(payload->hmac_alg_list);
- silc_free(payload->comp_alg_list);
- silc_free(payload);
- }
-}
-
-/* Encodes Key Exchange Payload into a SILC Buffer to be sent to the other
- end. */
-
-SilcSKEStatus silc_ske_payload_ke_encode(SilcSKE ske,
- SilcSKEKEPayload payload,
- SilcBuffer *return_buffer)
-{
- SilcBuffer buf;
- unsigned char *x_str;
- SilcUInt32 x_len;
- int ret;
-
- SILC_LOG_DEBUG(("Encoding KE Payload"));
-
- if (!payload)
- return SILC_SKE_STATUS_ERROR;
-
- if (ske->start_payload &&
- ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL &&
- !payload->sign_data) {
- SILC_LOG_DEBUG(("Signature data is missing"));
- return SILC_SKE_STATUS_ERROR;
- }
-
- /* Encode the integer into binary data */
- x_str = silc_mp_mp2bin(&payload->x, 0, &x_len);
-
- /* Allocate channel payload buffer. The length of the buffer
- is 4 + public key + 2 + x + 2 + signature. */
- buf = silc_buffer_alloc_size(4 + payload->pk_len + 2 + x_len +
- 2 + payload->sign_len);
- if (!buf)
- return SILC_SKE_STATUS_OUT_OF_MEMORY;
-
- /* Encode the payload */
- ret = silc_buffer_format(buf,
- SILC_STR_UI_SHORT(payload->pk_len),
- SILC_STR_UI_SHORT(payload->pk_type),
- SILC_STR_UI_XNSTRING(payload->pk_data,
- payload->pk_len),
- SILC_STR_UI_SHORT(x_len),
- SILC_STR_UI_XNSTRING(x_str, x_len),
- SILC_STR_UI_SHORT(payload->sign_len),
- SILC_STR_UI_XNSTRING(payload->sign_data,
- payload->sign_len),
- SILC_STR_END);
- if (ret == -1) {
- memset(x_str, 'F', x_len);
- silc_free(x_str);
- silc_buffer_free(buf);
- return SILC_SKE_STATUS_ERROR;
- }
-
- /* Return encoded buffer */
- *return_buffer = buf;
-
- SILC_LOG_HEXDUMP(("KE Payload"), buf->data, silc_buffer_len(buf));
-
- memset(x_str, 'F', x_len);
- silc_free(x_str);
-
- return SILC_SKE_STATUS_OK;
-}
-
-/* Parses the Key Exchange Payload. Parsed data is returned to allocated
- payload structure. */
-
-SilcSKEStatus silc_ske_payload_ke_decode(SilcSKE ske,
- SilcBuffer buffer,
- SilcSKEKEPayload *return_payload)
-{
- SilcSKEStatus status = SILC_SKE_STATUS_ERROR;
- SilcSKEKEPayload payload;
- unsigned char *x = NULL;
- SilcUInt16 x_len;
- SilcUInt32 tot_len = 0, len2;
- int ret;
-
- SILC_LOG_DEBUG(("Decoding Key Exchange Payload"));
-
- SILC_LOG_HEXDUMP(("KE Payload"), buffer->data, silc_buffer_len(buffer));
-
- payload = silc_calloc(1, sizeof(*payload));
- if (!payload)
- return SILC_SKE_STATUS_OUT_OF_MEMORY;
-
- len2 = silc_buffer_len(buffer);
-
- /* Parse start of the payload */
- ret = silc_buffer_unformat(buffer,
- SILC_STR_UI_SHORT(&payload->pk_len),
- SILC_STR_UI_SHORT(&payload->pk_type),
- SILC_STR_END);
- if (ret == -1) {
- SILC_LOG_ERROR(("Cannot decode public key from KE payload"));
- status = SILC_SKE_STATUS_BAD_PAYLOAD;
- goto err;
- }
-
- if (ske->start_payload &&
- ((payload->pk_type < SILC_SKE_PK_TYPE_SILC ||
- payload->pk_type > SILC_SKE_PK_TYPE_SPKI) || !payload->pk_len)) {
- SILC_LOG_ERROR(("Malformed public key in KE payload"));
- status = SILC_SKE_STATUS_BAD_PAYLOAD;
- goto err;
- }
-
- tot_len += payload->pk_len + 4;
-
- /* Parse PK data and the signature */
- silc_buffer_pull(buffer, 4);
- ret = silc_buffer_unformat(buffer,
- SILC_STR_UI_XNSTRING_ALLOC(&payload->pk_data,
- payload->pk_len),
- SILC_STR_UI16_NSTRING_ALLOC(&x, &x_len),
- SILC_STR_UI16_NSTRING_ALLOC(&payload->sign_data,
- &payload->sign_len),
- SILC_STR_END);
- if (ret == -1) {
- SILC_LOG_ERROR(("Malformed KE Payload"));
- status = SILC_SKE_STATUS_BAD_PAYLOAD;
- goto err;
- }
-
- tot_len += x_len + 2;
- tot_len += payload->sign_len + 2;
-
- if (x_len < 16) {
- SILC_LOG_ERROR(("Too short DH value in KE Payload"));
- status = SILC_SKE_STATUS_BAD_PAYLOAD;
- goto err;
- }
-
- if (ske->start_payload &&
- (ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL) &&
- (payload->sign_len < 3 || !payload->sign_data)) {
- SILC_LOG_ERROR(("The signature data is missing - both parties are "
- "required to do authentication"));
- status = SILC_SKE_STATUS_BAD_PAYLOAD;
- goto err;
- }
-
- if (tot_len != len2) {
- SILC_LOG_ERROR(("Garbage after KE payload"));
- status = SILC_SKE_STATUS_BAD_PAYLOAD_LENGTH;
- goto err;
- }
-
- /* Decode the binary data to integer */
- silc_mp_init(&payload->x);
- silc_mp_bin2mp(x, x_len, &payload->x);
- memset(x, 0, sizeof(x_len));
- silc_free(x);
-
- /* Return the payload */
- *return_payload = payload;
-
- return SILC_SKE_STATUS_OK;
-
- err:
- silc_free(payload->pk_data);
- silc_free(payload->sign_data);
- silc_free(x);
- silc_free(payload);
- ske->status = status;
- return status;
-}
-
-/* Free's KE Payload */
-
-void silc_ske_payload_ke_free(SilcSKEKEPayload payload)
-{
- if (payload) {
- silc_free(payload->pk_data);
- silc_mp_uninit(&payload->x);
- silc_free(payload->sign_data);
- silc_free(payload);
- }
-}
projects / crypto.git / blobdiff