-/******************************************************************************
-
- SILC_MESSAGE_FLAG_SIGNED Payload
-
-******************************************************************************/
-
-/* The SILC_MESSAGE_FLAG_SIGNED Payload */
-struct SilcSignedPayloadStruct {
- SilcUInt16 pk_len;
- SilcUInt16 pk_type;
- SilcUInt16 sign_len;
- unsigned char *pk_data;
- unsigned char *sign_data;
-};
-
-/* Encodes the data to be signed to SILC_MESSAGE_FLAG_SIGNED Payload */
-
-static SilcBuffer
-silc_signed_payload_encode_data(const unsigned char *message_payload,
- SilcUInt32 message_payload_len,
- unsigned char *pk,
- SilcUInt32 pk_len, SilcUInt32 pk_type)
-{
- SilcBuffer sign;
-
- sign = silc_buffer_alloc_size(message_payload_len + 4 + pk_len);
- if (!sign)
- return NULL;
-
- silc_buffer_format(sign,
- SILC_STR_UI_XNSTRING(message_payload,
- message_payload_len),
- SILC_STR_UI_SHORT(pk_len),
- SILC_STR_UI_SHORT(pk_type),
- SILC_STR_END);
-
- if (pk && pk_len) {
- silc_buffer_pull(sign, message_payload_len + 4);
- silc_buffer_format(sign,
- SILC_STR_UI_XNSTRING(pk, pk_len),
- SILC_STR_END);
- silc_buffer_push(sign, message_payload_len + 4);
- }
-
- return sign;
-}
-
-/* Parses the SILC_MESSAGE_FLAG_SIGNED Payload */
-
-SilcSignedPayload silc_signed_payload_parse(const unsigned char *data,
- SilcUInt32 data_len)
-{
- SilcSignedPayload sig;
- SilcBufferStruct buffer;
- int ret;
-
- SILC_LOG_DEBUG(("Parsing SILC_MESSAGE_FLAG_SIGNED Payload"));
-
- silc_buffer_set(&buffer, (unsigned char *)data, data_len);
- sig = silc_calloc(1, sizeof(*sig));
- if (!sig)
- return NULL;
-
- /* Parse the payload */
- ret = silc_buffer_unformat(&buffer,
- SILC_STR_UI_SHORT(&sig->pk_len),
- SILC_STR_UI_SHORT(&sig->pk_type),
- SILC_STR_END);
- if (ret == -1 || sig->pk_len > data_len - 4) {
- silc_signed_payload_free(sig);
- return NULL;
- }
-
- silc_buffer_pull(&buffer, 4);
- ret = silc_buffer_unformat(&buffer,
- SILC_STR_UI_XNSTRING_ALLOC(&sig->pk_data,
- sig->pk_len),
- SILC_STR_UI16_NSTRING_ALLOC(&sig->sign_data,
- &sig->sign_len),
- SILC_STR_END);
- if (ret == -1) {
- silc_signed_payload_free(sig);
- return NULL;
- }
- silc_buffer_push(&buffer, 4);
-
- /* Signature must be provided */
- if (sig->sign_len < 1) {
- silc_signed_payload_free(sig);
- return NULL;
- }
-
- return sig;
-}
-
-/* Encodes the SILC_MESSAGE_FLAG_SIGNED Payload and computes the digital
- signature. */
-
-SilcBuffer silc_signed_payload_encode(const unsigned char *message_payload,
- SilcUInt32 message_payload_len,
- SilcPublicKey public_key,
- SilcPrivateKey private_key,
- SilcHash hash,
- bool include_public_key)
-{
- SilcBuffer buffer, sign;
- SilcPKCS pkcs;
- unsigned char auth_data[2048];
- SilcUInt32 auth_len;
- unsigned char *pk = NULL;
- SilcUInt32 pk_len = 0;
- SilcUInt16 pk_type;
-
- if (!message_payload || !message_payload_len || !private_key || !hash)
- return NULL;
- if (include_public_key && !public_key)
- return NULL;
-
- if (include_public_key)
- pk = silc_pkcs_public_key_encode(public_key, &pk_len);
-
- /* Now we support only SILC style public key */
- pk_type = SILC_SKE_PK_TYPE_SILC;
-
- /* Encode the data to be signed */
- sign = silc_signed_payload_encode_data(message_payload,
- message_payload_len,
- pk, pk_len, pk_type);
- if (!sign) {
- silc_free(pk);
- return NULL;
- }
-
- /* Sign the buffer */
-
- /* Allocate PKCS object */
- if (!silc_pkcs_alloc(private_key->name, &pkcs)) {
- silc_buffer_clear(sign);
- silc_buffer_free(sign);
- silc_free(pk);
- return NULL;
- }
- silc_pkcs_private_key_set(pkcs, private_key);
-
- /* Compute the hash and the signature. */
- if (silc_pkcs_get_key_len(pkcs) / 8 > sizeof(auth_data) - 1 ||
- !silc_pkcs_sign_with_hash(pkcs, hash, sign->data, sign->len, auth_data,
- &auth_len)) {
- silc_buffer_clear(sign);
- silc_buffer_free(sign);
- silc_pkcs_free(pkcs);
- silc_free(pk);
- return NULL;
- }
-
- /* Encode the SILC_MESSAGE_FLAG_SIGNED Payload */
-
- buffer = silc_buffer_alloc_size(4 + pk_len + 2 + auth_len);
- if (!buffer) {
- silc_buffer_clear(sign);
- silc_buffer_free(sign);
- silc_pkcs_free(pkcs);
- memset(auth_data, 0, sizeof(auth_data));
- silc_free(pk);
- return NULL;
- }
-
- silc_buffer_format(sign,
- SILC_STR_UI_SHORT(pk_len),
- SILC_STR_UI_SHORT(pk_type),
- SILC_STR_END);
-
- if (pk_len && pk) {
- silc_buffer_pull(sign, 4);
- silc_buffer_format(sign,
- SILC_STR_UI_XNSTRING(pk, pk_len),
- SILC_STR_END);
- silc_buffer_push(sign, 4);
- }
-
- silc_buffer_pull(sign, 4 + pk_len);
- silc_buffer_format(sign,
- SILC_STR_UI_SHORT(auth_len),
- SILC_STR_UI_XNSTRING(auth_data, auth_len),
- SILC_STR_END);
- silc_buffer_push(sign, 4 + pk_len);
-
- memset(auth_data, 0, sizeof(auth_data));
- silc_pkcs_free(pkcs);
- silc_buffer_clear(sign);
- silc_buffer_free(sign);
- silc_free(pk);
-
- return buffer;
-}
-
-/* Free the payload */
-
-void silc_signed_payload_free(SilcSignedPayload sig)
-{
- if (sig) {
- memset(sig->sign_data, 0, sig->sign_len);
- silc_free(sig->sign_data);
- silc_free(sig->pk_data);
- silc_free(sig);
- }
-}
-
-/* Verify the signature in SILC_MESSAGE_FLAG_SIGNED Payload */
-
-int silc_signed_payload_verify(SilcSignedPayload sig,
- bool channel_message,
- void *message_payload,
- SilcPublicKey remote_public_key,
- SilcHash hash)
-{
- int ret = SILC_AUTH_FAILED;
-#if 0
- SilcBuffer sign;
- SilcPKCS pkcs;
-
- if (!sig || !remote_public_key || !hash)
- return ret;
-
- /* Generate the signature verification data */
- if (channel_message) {
- SilcChannelMessagePayload chm =
- (SilcChannelMessagePayload)message_payload;
- SilcBuffer tmp;
-
- /* Encode Channel Message Payload */
- tmp = silc_buffer_alloc_size(6 + chm->data_len + chm->pad_len +
- chm->iv_len);
- silc_buffer_format(tmp,
- SILC_STR_UI_SHORT(chm->flags),
- SILC_STR_UI_SHORT(chm->data_len),
- SILC_STR_UI_XNSTRING(chm->data, chm->data_len),
- SILC_STR_UI_SHORT(chm->pad_len),
- SILC_STR_UI_XNSTRING(chm->pad, chm->pad_len),
- SILC_STR_UI_XNSTRING(chm->iv, chm->iv_len),
- SILC_STR_END);
-
- sign = silc_signed_payload_encode_data(tmp->data, tmp->len,
- sig->pk_data, sig->pk_len,
- sig->pk_type);
- silc_buffer_clear(tmp);
- silc_buffer_free(tmp);
- } else {
- SilcPrivateMessagePayload prm =
- (SilcPrivateMessagePayload)message_payload;
- SilcBuffer tmp;
-
- /* Encode Private Message Payload */
- tmp = silc_buffer_alloc_size(4 + prm->data_len +
- SILC_PRIVATE_MESSAGE_PAD(4 + prm->data_len));
- silc_buffer_format(tmp,
- SILC_STR_UI_SHORT(prm->flags),
- SILC_STR_UI_SHORT(prm->message_len),
- SILC_STR_UI_XNSTRING(prm->message, prm->message_len),
- SILC_STR_END);
-
- sign = silc_signed_payload_encode_data(tmp->data, tmp->len,
- sig->pk_data, sig->pk_len,
- sig->pk_type);
- silc_buffer_clear(tmp);
- silc_buffer_free(tmp);
- }
-
- if (!sign)
- return ret;
-
- /* Allocate PKCS object */
- if (!silc_pkcs_alloc(remote_public_key->name, &pkcs)) {
- silc_buffer_clear(sign);
- silc_buffer_free(sign);
- return ret;
- }
- silc_pkcs_public_key_set(pkcs, remote_public_key);
-
- /* Verify the authentication data */
- if (!silc_pkcs_verify_with_hash(pkcs, hash, payload->sign_data
- payload->sign_len,
- sign->data, sign->len)) {
-
- silc_buffer_clear(sign);
- silc_buffer_free(sign);
- silc_pkcs_free(pkcs);
- SILC_LOG_DEBUG(("Signature verification failed"));
- return ret;
- }
-
- ret = SILC_AUTH_OK;
-
- silc_buffer_clear(sign);
- silc_buffer_free(sign);
- silc_pkcs_free(pkcs);
-
- SILC_LOG_DEBUG(("Signature verification successful"));
-
-#endif
- return ret;
-}
-
-/* Return the public key from the payload */