mbedtls/library/pk.c
2019-02-05 05:09:05 -05:00

647 lines
18 KiB
C

/*
* Public Key abstraction layer
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_PK_C)
#include "mbedtls/pk.h"
#include "mbedtls/pk_internal.h"
#include "mbedtls/platform_util.h"
#if defined(MBEDTLS_RSA_C)
#include "mbedtls/rsa.h"
#endif
#if defined(MBEDTLS_ECP_C)
#include "mbedtls/ecp.h"
#endif
#if defined(MBEDTLS_ECDSA_C)
#include "mbedtls/ecdsa.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "mbedtls/psa_util.h"
#endif
#include <limits.h>
#include <stdint.h>
/* Parameter validation macros based on platform_util.h */
#define PK_VALIDATE_RET( cond ) \
MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_PK_BAD_INPUT_DATA )
#define PK_VALIDATE( cond ) \
MBEDTLS_INTERNAL_VALIDATE( cond )
/*
* Initialise a mbedtls_pk_context
*/
void mbedtls_pk_init( mbedtls_pk_context *ctx )
{
PK_VALIDATE( ctx != NULL );
ctx->pk_info = NULL;
ctx->pk_ctx = NULL;
}
/*
* Free (the components of) a mbedtls_pk_context
*/
void mbedtls_pk_free( mbedtls_pk_context *ctx )
{
if( ctx == NULL )
return;
if ( ctx->pk_info != NULL )
ctx->pk_info->ctx_free_func( ctx->pk_ctx );
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_pk_context ) );
}
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
/*
* Initialize a restart context
*/
void mbedtls_pk_restart_init( mbedtls_pk_restart_ctx *ctx )
{
PK_VALIDATE( ctx != NULL );
ctx->pk_info = NULL;
ctx->rs_ctx = NULL;
}
/*
* Free the components of a restart context
*/
void mbedtls_pk_restart_free( mbedtls_pk_restart_ctx *ctx )
{
if( ctx == NULL || ctx->pk_info == NULL ||
ctx->pk_info->rs_free_func == NULL )
{
return;
}
ctx->pk_info->rs_free_func( ctx->rs_ctx );
ctx->pk_info = NULL;
ctx->rs_ctx = NULL;
}
#endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
/*
* Get pk_info structure from type
*/
const mbedtls_pk_info_t * mbedtls_pk_info_from_type( mbedtls_pk_type_t pk_type )
{
switch( pk_type ) {
#if defined(MBEDTLS_RSA_C)
case MBEDTLS_PK_RSA:
return( &mbedtls_rsa_info );
#endif
#if defined(MBEDTLS_ECP_C)
case MBEDTLS_PK_ECKEY:
return( &mbedtls_eckey_info );
case MBEDTLS_PK_ECKEY_DH:
return( &mbedtls_eckeydh_info );
#endif
#if defined(MBEDTLS_ECDSA_C)
case MBEDTLS_PK_ECDSA:
return( &mbedtls_ecdsa_info );
#endif
/* MBEDTLS_PK_RSA_ALT omitted on purpose */
default:
return( NULL );
}
}
/*
* Initialise context
*/
int mbedtls_pk_setup( mbedtls_pk_context *ctx, const mbedtls_pk_info_t *info )
{
PK_VALIDATE_RET( ctx != NULL );
if( info == NULL || ctx->pk_info != NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
if( ( ctx->pk_ctx = info->ctx_alloc_func() ) == NULL )
return( MBEDTLS_ERR_PK_ALLOC_FAILED );
ctx->pk_info = info;
return( 0 );
}
#if defined(MBEDTLS_USE_PSA_CRYPTO)
/*
* Initialise a PSA-wrapping context
*/
int mbedtls_pk_setup_opaque( mbedtls_pk_context *ctx, const psa_key_handle_t key )
{
const mbedtls_pk_info_t * const info = &mbedtls_pk_opaque_info;
psa_key_handle_t *pk_ctx;
psa_key_type_t type;
if( ctx == NULL || ctx->pk_info != NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
if( PSA_SUCCESS != psa_get_key_information( key, &type, NULL ) )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
/* Current implementation of can_do() relies on this. */
if( ! PSA_KEY_TYPE_IS_ECC_KEYPAIR( type ) )
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE) ;
if( ( ctx->pk_ctx = info->ctx_alloc_func() ) == NULL )
return( MBEDTLS_ERR_PK_ALLOC_FAILED );
ctx->pk_info = info;
pk_ctx = (psa_key_handle_t *) ctx->pk_ctx;
*pk_ctx = key;
return( 0 );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
/*
* Initialize an RSA-alt context
*/
int mbedtls_pk_setup_rsa_alt( mbedtls_pk_context *ctx, void * key,
mbedtls_pk_rsa_alt_decrypt_func decrypt_func,
mbedtls_pk_rsa_alt_sign_func sign_func,
mbedtls_pk_rsa_alt_key_len_func key_len_func )
{
mbedtls_rsa_alt_context *rsa_alt;
const mbedtls_pk_info_t *info = &mbedtls_rsa_alt_info;
PK_VALIDATE_RET( ctx != NULL );
if( ctx->pk_info != NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
if( ( ctx->pk_ctx = info->ctx_alloc_func() ) == NULL )
return( MBEDTLS_ERR_PK_ALLOC_FAILED );
ctx->pk_info = info;
rsa_alt = (mbedtls_rsa_alt_context *) ctx->pk_ctx;
rsa_alt->key = key;
rsa_alt->decrypt_func = decrypt_func;
rsa_alt->sign_func = sign_func;
rsa_alt->key_len_func = key_len_func;
return( 0 );
}
#endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
/*
* Tell if a PK can do the operations of the given type
*/
int mbedtls_pk_can_do( const mbedtls_pk_context *ctx, mbedtls_pk_type_t type )
{
/* A context with null pk_info is not set up yet and can't do anything.
* For backward compatibility, also accept NULL instead of a context
* pointer. */
if( ctx == NULL || ctx->pk_info == NULL )
return( 0 );
return( ctx->pk_info->can_do( type ) );
}
/*
* Helper for mbedtls_pk_sign and mbedtls_pk_verify
*/
static inline int pk_hashlen_helper( mbedtls_md_type_t md_alg, size_t *hash_len )
{
const mbedtls_md_info_t *md_info;
if( *hash_len != 0 )
return( 0 );
if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL )
return( -1 );
*hash_len = mbedtls_md_get_size( md_info );
return( 0 );
}
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
/*
* Helper to set up a restart context if needed
*/
static int pk_restart_setup( mbedtls_pk_restart_ctx *ctx,
const mbedtls_pk_info_t *info )
{
/* Don't do anything if already set up or invalid */
if( ctx == NULL || ctx->pk_info != NULL )
return( 0 );
/* Should never happen when we're called */
if( info->rs_alloc_func == NULL || info->rs_free_func == NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
if( ( ctx->rs_ctx = info->rs_alloc_func() ) == NULL )
return( MBEDTLS_ERR_PK_ALLOC_FAILED );
ctx->pk_info = info;
return( 0 );
}
#endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
/*
* Verify a signature (restartable)
*/
int mbedtls_pk_verify_restartable( mbedtls_pk_context *ctx,
mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len,
mbedtls_pk_restart_ctx *rs_ctx )
{
PK_VALIDATE_RET( ctx != NULL );
PK_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE && hash_len == 0 ) ||
hash != NULL );
PK_VALIDATE_RET( sig != NULL );
if( ctx->pk_info == NULL ||
pk_hashlen_helper( md_alg, &hash_len ) != 0 )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
/* optimization: use non-restartable version if restart disabled */
if( rs_ctx != NULL &&
mbedtls_ecp_restart_is_enabled() &&
ctx->pk_info->verify_rs_func != NULL )
{
int ret;
if( ( ret = pk_restart_setup( rs_ctx, ctx->pk_info ) ) != 0 )
return( ret );
ret = ctx->pk_info->verify_rs_func( ctx->pk_ctx,
md_alg, hash, hash_len, sig, sig_len, rs_ctx->rs_ctx );
if( ret != MBEDTLS_ERR_ECP_IN_PROGRESS )
mbedtls_pk_restart_free( rs_ctx );
return( ret );
}
#else /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
(void) rs_ctx;
#endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
if( ctx->pk_info->verify_func == NULL )
return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
return( ctx->pk_info->verify_func( ctx->pk_ctx, md_alg, hash, hash_len,
sig, sig_len ) );
}
/*
* Verify a signature
*/
int mbedtls_pk_verify( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len )
{
return( mbedtls_pk_verify_restartable( ctx, md_alg, hash, hash_len,
sig, sig_len, NULL ) );
}
/*
* Verify a signature with options
*/
int mbedtls_pk_verify_ext( mbedtls_pk_type_t type, const void *options,
mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len )
{
PK_VALIDATE_RET( ctx != NULL );
PK_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE && hash_len == 0 ) ||
hash != NULL );
PK_VALIDATE_RET( sig != NULL );
if( ctx->pk_info == NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
if( ! mbedtls_pk_can_do( ctx, type ) )
return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
if( type == MBEDTLS_PK_RSASSA_PSS )
{
#if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PKCS1_V21)
int ret;
const mbedtls_pk_rsassa_pss_options *pss_opts;
#if SIZE_MAX > UINT_MAX
if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
#endif /* SIZE_MAX > UINT_MAX */
if( options == NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
pss_opts = (const mbedtls_pk_rsassa_pss_options *) options;
if( sig_len < mbedtls_pk_get_len( ctx ) )
return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
ret = mbedtls_rsa_rsassa_pss_verify_ext( mbedtls_pk_rsa( *ctx ),
NULL, NULL, MBEDTLS_RSA_PUBLIC,
md_alg, (unsigned int) hash_len, hash,
pss_opts->mgf1_hash_id,
pss_opts->expected_salt_len,
sig );
if( ret != 0 )
return( ret );
if( sig_len > mbedtls_pk_get_len( ctx ) )
return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
return( 0 );
#else
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
#endif /* MBEDTLS_RSA_C && MBEDTLS_PKCS1_V21 */
}
/* General case: no options */
if( options != NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
return( mbedtls_pk_verify( ctx, md_alg, hash, hash_len, sig, sig_len ) );
}
/*
* Make a signature (restartable)
*/
int mbedtls_pk_sign_restartable( mbedtls_pk_context *ctx,
mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
mbedtls_pk_restart_ctx *rs_ctx )
{
PK_VALIDATE_RET( ctx != NULL );
PK_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE && hash_len == 0 ) ||
hash != NULL );
PK_VALIDATE_RET( sig != NULL );
if( ctx->pk_info == NULL ||
pk_hashlen_helper( md_alg, &hash_len ) != 0 )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
/* optimization: use non-restartable version if restart disabled */
if( rs_ctx != NULL &&
mbedtls_ecp_restart_is_enabled() &&
ctx->pk_info->sign_rs_func != NULL )
{
int ret;
if( ( ret = pk_restart_setup( rs_ctx, ctx->pk_info ) ) != 0 )
return( ret );
ret = ctx->pk_info->sign_rs_func( ctx->pk_ctx, md_alg,
hash, hash_len, sig, sig_len, f_rng, p_rng, rs_ctx->rs_ctx );
if( ret != MBEDTLS_ERR_ECP_IN_PROGRESS )
mbedtls_pk_restart_free( rs_ctx );
return( ret );
}
#else /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
(void) rs_ctx;
#endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
if( ctx->pk_info->sign_func == NULL )
return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
return( ctx->pk_info->sign_func( ctx->pk_ctx, md_alg, hash, hash_len,
sig, sig_len, f_rng, p_rng ) );
}
/*
* Make a signature
*/
int mbedtls_pk_sign( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
{
return( mbedtls_pk_sign_restartable( ctx, md_alg, hash, hash_len,
sig, sig_len, f_rng, p_rng, NULL ) );
}
/*
* Decrypt message
*/
int mbedtls_pk_decrypt( mbedtls_pk_context *ctx,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen, size_t osize,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
{
PK_VALIDATE_RET( ctx != NULL );
PK_VALIDATE_RET( input != NULL || ilen == 0 );
PK_VALIDATE_RET( output != NULL || osize == 0 );
PK_VALIDATE_RET( olen != NULL );
if( ctx->pk_info == NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
if( ctx->pk_info->decrypt_func == NULL )
return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
return( ctx->pk_info->decrypt_func( ctx->pk_ctx, input, ilen,
output, olen, osize, f_rng, p_rng ) );
}
/*
* Encrypt message
*/
int mbedtls_pk_encrypt( mbedtls_pk_context *ctx,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen, size_t osize,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
{
PK_VALIDATE_RET( ctx != NULL );
PK_VALIDATE_RET( input != NULL || ilen == 0 );
PK_VALIDATE_RET( output != NULL || osize == 0 );
PK_VALIDATE_RET( olen != NULL );
if( ctx->pk_info == NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
if( ctx->pk_info->encrypt_func == NULL )
return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
return( ctx->pk_info->encrypt_func( ctx->pk_ctx, input, ilen,
output, olen, osize, f_rng, p_rng ) );
}
/*
* Check public-private key pair
*/
int mbedtls_pk_check_pair( const mbedtls_pk_context *pub, const mbedtls_pk_context *prv )
{
PK_VALIDATE_RET( pub != NULL );
PK_VALIDATE_RET( prv != NULL );
if( pub->pk_info == NULL ||
prv->pk_info == NULL )
{
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
}
if( prv->pk_info->check_pair_func == NULL )
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
if( prv->pk_info->type == MBEDTLS_PK_RSA_ALT )
{
if( pub->pk_info->type != MBEDTLS_PK_RSA )
return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
}
else
{
if( pub->pk_info != prv->pk_info )
return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
}
return( prv->pk_info->check_pair_func( pub->pk_ctx, prv->pk_ctx ) );
}
/*
* Get key size in bits
*/
size_t mbedtls_pk_get_bitlen( const mbedtls_pk_context *ctx )
{
/* For backward compatibility, accept NULL or a context that
* isn't set up yet, and return a fake value that should be safe. */
if( ctx == NULL || ctx->pk_info == NULL )
return( 0 );
return( ctx->pk_info->get_bitlen( ctx->pk_ctx ) );
}
/*
* Export debug information
*/
int mbedtls_pk_debug( const mbedtls_pk_context *ctx, mbedtls_pk_debug_item *items )
{
PK_VALIDATE_RET( ctx != NULL );
if( ctx->pk_info == NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
if( ctx->pk_info->debug_func == NULL )
return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
ctx->pk_info->debug_func( ctx->pk_ctx, items );
return( 0 );
}
/*
* Access the PK type name
*/
const char *mbedtls_pk_get_name( const mbedtls_pk_context *ctx )
{
if( ctx == NULL || ctx->pk_info == NULL )
return( "invalid PK" );
return( ctx->pk_info->name );
}
/*
* Access the PK type
*/
mbedtls_pk_type_t mbedtls_pk_get_type( const mbedtls_pk_context *ctx )
{
if( ctx == NULL || ctx->pk_info == NULL )
return( MBEDTLS_PK_NONE );
return( ctx->pk_info->type );
}
#if defined(MBEDTLS_USE_PSA_CRYPTO)
/*
* Load the key to a PSA key slot,
* then turn the PK context into a wrapper for that key slot.
*
* Currently only works for EC private keys.
*/
int mbedtls_pk_wrap_as_opaque( mbedtls_pk_context *pk,
psa_key_handle_t *slot,
psa_algorithm_t hash_alg )
{
#if !defined(MBEDTLS_ECP_C)
return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
#else
psa_key_handle_t key;
const mbedtls_ecp_keypair *ec;
unsigned char d[MBEDTLS_ECP_MAX_BYTES];
size_t d_len;
psa_ecc_curve_t curve_id;
psa_key_type_t key_type;
psa_key_policy_t policy;
int ret;
/* export the private key material in the format PSA wants */
if( mbedtls_pk_get_type( pk ) != MBEDTLS_PK_ECKEY )
return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
ec = mbedtls_pk_ec( *pk );
d_len = ( ec->grp.nbits + 7 ) / 8;
if( ( ret = mbedtls_mpi_write_binary( &ec->d, d, d_len ) ) != 0 )
return( ret );
curve_id = mbedtls_ecp_curve_info_from_grp_id( ec->grp.id )->tls_id;
key_type = PSA_KEY_TYPE_ECC_KEYPAIR(
mbedtls_psa_parse_tls_ecc_group ( curve_id ) );
/* allocate a key slot */
if( PSA_SUCCESS != psa_allocate_key( &key ) )
return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
/* set policy */
policy = psa_key_policy_init();
psa_key_policy_set_usage( &policy, PSA_KEY_USAGE_SIGN,
PSA_ALG_ECDSA(hash_alg) );
if( PSA_SUCCESS != psa_set_key_policy( key, &policy ) )
return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
/* import private key in slot */
if( PSA_SUCCESS != psa_import_key( key, key_type, d, d_len ) )
return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
/* remember slot number to be destroyed later by caller */
*slot = key;
/* make PK context wrap the key slot */
mbedtls_pk_free( pk );
mbedtls_pk_init( pk );
return( mbedtls_pk_setup_opaque( pk, key ) );
#endif /* MBEDTLS_ECP_C */
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#endif /* MBEDTLS_PK_C */