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/*
* Copyright (C) 2001 Nikos Mavroyanopoulos
*
* This file is part of GNUTLS.
*
* GNUTLS 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.
*
* GNUTLS 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include <gnutls_int.h>
#include <gnutls_errors.h>
#include <x509_b64.h>
#include <auth_x509.h>
#include <gnutls_cert.h>
#include <x509_asn1.h>
#include <x509_der.h>
#include <gnutls_datum.h>
#include <gnutls_gcry.h>
#include <gnutls_privkey.h>
#include <gnutls_global.h>
#include <gnutls_pk.h>
#include <debug.h>
#include <gnutls_buffers.h>
#include <gnutls_sig.h>
/* Generates a signature of all the previous sent packets in the
* handshake procedure.
*/
int _gnutls_generate_sig_from_hdata( GNUTLS_STATE state, gnutls_cert* cert, gnutls_private_key *pkey, gnutls_datum *signature) {
gnutls_datum data;
int size = gnutls_get_handshake_buffer_size( state);
int ret;
data.data = gnutls_malloc(size);
data.size = size;
if (data.data==NULL) {
gnutls_assert();
return GNUTLS_E_MEMORY_ERROR;
}
gnutls_read_handshake_buffer( state, data.data, data.size);
ret = _gnutls_pkcs1_rsa_generate_sig( cert, pkey, &data, signature);
gnutls_free_datum( &data);
if (ret < 0) {
gnutls_assert();
return ret;
}
return ret;
}
/* Generates a signature of all the random data and the parameters.
* Used in DHE_* ciphersuites.
*/
int _gnutls_generate_sig_params( GNUTLS_STATE state, gnutls_cert* cert, gnutls_private_key *pkey, gnutls_datum* params, gnutls_datum *signature)
{
gnutls_datum sdata;
int size = 2*TLS_RANDOM_SIZE;
int ret;
sdata.data = gnutls_malloc( size+params->size);
sdata.size = size + params->size;
if (sdata.data==NULL) {
gnutls_assert();
return GNUTLS_E_MEMORY_ERROR;
}
memcpy( sdata.data, state->security_parameters.client_random, TLS_RANDOM_SIZE);
memcpy( &sdata.data[TLS_RANDOM_SIZE], state->security_parameters.server_random, TLS_RANDOM_SIZE);
memcpy( &sdata.data[2*TLS_RANDOM_SIZE], params->data, params->size);
ret = _gnutls_pkcs1_rsa_generate_sig( cert, pkey, &sdata, signature);
gnutls_free_datum( &sdata);
if (ret < 0) {
gnutls_assert();
return ret;
}
return ret;
}
/* This will create a PKCS1 signature, as defined in the TLS protocol.
* Cert is the certificate of the corresponding private key. It is only checked if
* it supports signing.
*/
int _gnutls_pkcs1_rsa_generate_sig( gnutls_cert* cert, gnutls_private_key *pkey, const gnutls_datum *data, gnutls_datum *signature)
{
int ret;
opaque digest[20+16];
gnutls_datum tmpdata;
GNUTLS_HASH_HANDLE td;
/* If our certificate supports signing
*/
if ( cert != NULL)
if ( cert->keyUsage != 0)
if ( !(cert->keyUsage & X509KEY_DIGITAL_SIGNATURE)) {
gnutls_assert();
return GNUTLS_E_X509_KEY_USAGE_VIOLATION;
}
switch(pkey->pk_algorithm) {
case GNUTLS_PK_RSA:
td = gnutls_hash_init( GNUTLS_MAC_MD5);
if (td==NULL) {
gnutls_assert();
return GNUTLS_E_MEMORY_ERROR;
}
gnutls_hash( td, data->data, data->size);
gnutls_hash_deinit( td, digest);
td = gnutls_hash_init( GNUTLS_MAC_SHA);
if (td==NULL) {
gnutls_assert();
return GNUTLS_E_MEMORY_ERROR;
}
gnutls_hash( td, data->data, data->size);
gnutls_hash_deinit( td, &digest[16]);
tmpdata.data = digest;
tmpdata.size = 20+16; /* md5 + sha */
break;
default:
gnutls_assert();
return GNUTLS_E_UNIMPLEMENTED_FEATURE;
break;
}
/* encrypt der */
if ( (ret=_gnutls_pkcs1_rsa_encrypt( signature, tmpdata, pkey->params[0], pkey->params[1], 1)) < 0) {
gnutls_assert();
return ret;
}
return 0;
}
int _gnutls_pkcs1_rsa_verify_sig( gnutls_cert *cert, const gnutls_datum *data, gnutls_datum *signature) {
int ret;
gnutls_datum plain, vdata;
opaque digest[20+16];
GNUTLS_HASH_HANDLE td;
if (cert->version == 0 || cert==NULL) { /* this is the only way to check
* if it is initialized
*/
gnutls_assert();
return GNUTLS_E_X509_CERTIFICATE_ERROR;
}
/* If the certificate supports signing continue.
*/
if ( cert != NULL)
if ( cert->keyUsage != 0)
if ( !(cert->keyUsage & X509KEY_DIGITAL_SIGNATURE)) {
gnutls_assert();
return GNUTLS_E_X509_KEY_USAGE_VIOLATION;
}
switch(cert->subject_pk_algorithm) {
case GNUTLS_PK_RSA:
td = gnutls_hash_init( GNUTLS_MAC_MD5);
if (td==NULL) {
gnutls_assert();
return GNUTLS_E_MEMORY_ERROR;
}
gnutls_hash( td, data->data, data->size);
gnutls_hash_deinit( td, digest);
td = gnutls_hash_init( GNUTLS_MAC_SHA);
if (td==NULL) {
gnutls_assert();
return GNUTLS_E_MEMORY_ERROR;
}
gnutls_hash( td, data->data, data->size);
gnutls_hash_deinit( td, &digest[16]);
vdata.data = digest;
vdata.size = 20+16; /* md5 + sha */
break;
default:
gnutls_assert();
return GNUTLS_E_UNIMPLEMENTED_FEATURE;
}
/* decrypt signature */
if ( (ret=_gnutls_pkcs1_rsa_decrypt( &plain, *signature, cert->params[1], cert->params[0], 1)) < 0) {
gnutls_assert();
return ret;
}
if (plain.size != vdata.size) {
gnutls_assert();
gnutls_sfree_datum( &plain);
return GNUTLS_E_PK_SIGNATURE_FAILED;
}
if ( memcmp(plain.data, vdata.data, plain.size)!=0) {
gnutls_assert();
gnutls_sfree_datum( &plain);
return GNUTLS_E_PK_SIGNATURE_FAILED;
}
gnutls_sfree_datum( &plain);
return 0;
}
/* Verifies a TLS signature (like the one in the client certificate
* verify message). ubuffer_size is a buffer to remove from the hash buffer
* in order to avoid hashing the last message.
*/
int _gnutls_verify_sig_hdata( GNUTLS_STATE state, gnutls_cert *cert, gnutls_datum* signature, int ubuffer_size) {
gnutls_datum data;
int size = gnutls_get_handshake_buffer_size( state) - ubuffer_size; /* do not get the last message */
int ret;
data.data = gnutls_malloc(size);
data.size = size;
if (data.data==NULL) {
gnutls_assert();
return GNUTLS_E_MEMORY_ERROR;
}
gnutls_read_handshake_buffer( state, data.data, data.size);
ret = _gnutls_pkcs1_rsa_verify_sig( cert, &data, signature);
if (ret < 0) {
gnutls_assert();
return ret;
}
return ret;
}
/* Generates a signature of all the random data and the parameters.
* Used in DHE_* ciphersuites.
*/
int _gnutls_verify_sig_params( GNUTLS_STATE state, gnutls_cert *cert, const gnutls_datum* params, gnutls_datum *signature)
{
gnutls_datum sdata;
int size = 2*TLS_RANDOM_SIZE;
int ret;
sdata.data = gnutls_malloc( size+params->size);
sdata.size = size + params->size;
if (sdata.data==NULL) {
gnutls_assert();
return GNUTLS_E_MEMORY_ERROR;
}
memcpy( sdata.data, state->security_parameters.client_random, TLS_RANDOM_SIZE);
memcpy( &sdata.data[TLS_RANDOM_SIZE], state->security_parameters.server_random, TLS_RANDOM_SIZE);
memcpy( &sdata.data[2*TLS_RANDOM_SIZE], params->data, params->size);
ret = _gnutls_pkcs1_rsa_verify_sig( cert, &sdata, signature);
gnutls_free_datum( &sdata);
if (ret < 0) {
gnutls_assert();
return ret;
}
return ret;
}
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