/*
- silcauth.c
+ silcauth.c
Author: Pekka Riikonen <priikone@silcnet.org>
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
#include "silcincludes.h"
#include "silcauth.h"
+#include "silcchannel_i.h"
+#include "silcprivate_i.h"
/******************************************************************************
if (ret_len)
*ret_len = buf->len;
+ silc_buffer_clear(buf);
silc_buffer_free(buf);
silc_free(id_data);
silc_free(pk);
return NULL;
/* Allocate PKCS object */
- if (!silc_pkcs_alloc(public_key->name, &pkcs)) {
+ if (!silc_pkcs_alloc(private_key->name, &pkcs)) {
memset(tmp, 0, tmp_len);
silc_free(tmp);
return NULL;
{
return payload->port;
}
+
+/******************************************************************************
+
+ 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 */
+
+SilcPublicKey silc_signed_payload_get_public_key(SilcSignedPayload sig)
+{
+ SilcPublicKey pk;
+
+ if (!sig->pk_data || !silc_pkcs_public_key_decode(sig->pk_data,
+ sig->pk_len, &pk))
+ return NULL;
+
+ return pk;
+}
projects / silc.git / blobdiff