mbedtls/library/pk_wrap.c
Hanno Becker 5d5e90a610 Adapt ecdsa_verify_wrap() to new EC public key format
Previously, PSA used SubjectPublicKeyInfo structures to serialize EC public keys.
This has recently been changed to using ECPoint structures instead, but the wrapper
making PSA ECDSA verification available through Mbed TLS' PK API hasn't yet been
adapted accordingly - which is what this commit does.

Luckily, Mbed TLS' PK API offers two functions mbedtls_pk_write_pubkey()
and mbedtls_pk_write_pubkey_der(), the latter exporting a SubjectPublicKeyInfo
structure and the former exporting an ECPoint structure in case of EC public
keys. For the adaptation of the ECDSA wrapper ecdsa_verify_wrap() it is therefore
sufficient to use mbedtls_pk_write_pubkey() instead of mbedtls_pk_write_pubkey_der().
2019-01-28 11:41:37 +00:00

1058 lines
30 KiB
C

/*
* Public Key abstraction layer: wrapper functions
*
* 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_internal.h"
/* Even if RSA not activated, for the sake of RSA-alt */
#include "mbedtls/rsa.h"
#include <string.h>
#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/asn1write.h"
#endif
#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
#include "mbedtls/platform_util.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#include "mbedtls/psa_util.h"
#include "mbedtls/asn1.h"
#endif
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#include <limits.h>
#include <stdint.h>
#if defined(MBEDTLS_RSA_C)
static int rsa_can_do( mbedtls_pk_type_t type )
{
return( type == MBEDTLS_PK_RSA ||
type == MBEDTLS_PK_RSASSA_PSS );
}
static size_t rsa_get_bitlen( const void *ctx )
{
const mbedtls_rsa_context * rsa = (const mbedtls_rsa_context *) ctx;
return( 8 * mbedtls_rsa_get_len( rsa ) );
}
static int rsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len )
{
int ret;
mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
size_t rsa_len = mbedtls_rsa_get_len( rsa );
#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( sig_len < rsa_len )
return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
if( ( ret = mbedtls_rsa_pkcs1_verify( rsa, NULL, NULL,
MBEDTLS_RSA_PUBLIC, md_alg,
(unsigned int) hash_len, hash, sig ) ) != 0 )
return( ret );
/* The buffer contains a valid signature followed by extra data.
* We have a special error code for that so that so that callers can
* use mbedtls_pk_verify() to check "Does the buffer start with a
* valid signature?" and not just "Does the buffer contain a valid
* signature?". */
if( sig_len > rsa_len )
return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
return( 0 );
}
static int rsa_sign_wrap( void *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_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
#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 */
*sig_len = mbedtls_rsa_get_len( rsa );
return( mbedtls_rsa_pkcs1_sign( rsa, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
md_alg, (unsigned int) hash_len, hash, sig ) );
}
static int rsa_decrypt_wrap( void *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 )
{
mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
if( ilen != mbedtls_rsa_get_len( rsa ) )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
return( mbedtls_rsa_pkcs1_decrypt( rsa, f_rng, p_rng,
MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
}
static int rsa_encrypt_wrap( void *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 )
{
mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
*olen = mbedtls_rsa_get_len( rsa );
if( *olen > osize )
return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE );
return( mbedtls_rsa_pkcs1_encrypt( rsa, f_rng, p_rng, MBEDTLS_RSA_PUBLIC,
ilen, input, output ) );
}
static int rsa_check_pair_wrap( const void *pub, const void *prv )
{
return( mbedtls_rsa_check_pub_priv( (const mbedtls_rsa_context *) pub,
(const mbedtls_rsa_context *) prv ) );
}
static void *rsa_alloc_wrap( void )
{
void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_context ) );
if( ctx != NULL )
mbedtls_rsa_init( (mbedtls_rsa_context *) ctx, 0, 0 );
return( ctx );
}
static void rsa_free_wrap( void *ctx )
{
mbedtls_rsa_free( (mbedtls_rsa_context *) ctx );
mbedtls_free( ctx );
}
static void rsa_debug( const void *ctx, mbedtls_pk_debug_item *items )
{
items->type = MBEDTLS_PK_DEBUG_MPI;
items->name = "rsa.N";
items->value = &( ((mbedtls_rsa_context *) ctx)->N );
items++;
items->type = MBEDTLS_PK_DEBUG_MPI;
items->name = "rsa.E";
items->value = &( ((mbedtls_rsa_context *) ctx)->E );
}
const mbedtls_pk_info_t mbedtls_rsa_info = {
MBEDTLS_PK_RSA,
"RSA",
rsa_get_bitlen,
rsa_can_do,
rsa_verify_wrap,
rsa_sign_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
rsa_decrypt_wrap,
rsa_encrypt_wrap,
rsa_check_pair_wrap,
rsa_alloc_wrap,
rsa_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
rsa_debug,
};
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECP_C)
/*
* Generic EC key
*/
static int eckey_can_do( mbedtls_pk_type_t type )
{
return( type == MBEDTLS_PK_ECKEY ||
type == MBEDTLS_PK_ECKEY_DH ||
type == MBEDTLS_PK_ECDSA );
}
static size_t eckey_get_bitlen( const void *ctx )
{
return( ((mbedtls_ecp_keypair *) ctx)->grp.pbits );
}
#if defined(MBEDTLS_ECDSA_C)
/* Forward declarations */
static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len );
static int ecdsa_sign_wrap( void *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 );
static int eckey_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len )
{
int ret;
mbedtls_ecdsa_context ecdsa;
mbedtls_ecdsa_init( &ecdsa );
if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
ret = ecdsa_verify_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len );
mbedtls_ecdsa_free( &ecdsa );
return( ret );
}
static int eckey_sign_wrap( void *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 )
{
int ret;
mbedtls_ecdsa_context ecdsa;
mbedtls_ecdsa_init( &ecdsa );
if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
ret = ecdsa_sign_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len,
f_rng, p_rng );
mbedtls_ecdsa_free( &ecdsa );
return( ret );
}
#if defined(MBEDTLS_ECP_RESTARTABLE)
/* Forward declarations */
static int ecdsa_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len,
void *rs_ctx );
static int ecdsa_sign_rs_wrap( void *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,
void *rs_ctx );
/*
* Restart context for ECDSA operations with ECKEY context
*
* We need to store an actual ECDSA context, as we need to pass the same to
* the underlying ecdsa function, so we can't create it on the fly every time.
*/
typedef struct
{
mbedtls_ecdsa_restart_ctx ecdsa_rs;
mbedtls_ecdsa_context ecdsa_ctx;
} eckey_restart_ctx;
static void *eckey_rs_alloc( void )
{
eckey_restart_ctx *rs_ctx;
void *ctx = mbedtls_calloc( 1, sizeof( eckey_restart_ctx ) );
if( ctx != NULL )
{
rs_ctx = ctx;
mbedtls_ecdsa_restart_init( &rs_ctx->ecdsa_rs );
mbedtls_ecdsa_init( &rs_ctx->ecdsa_ctx );
}
return( ctx );
}
static void eckey_rs_free( void *ctx )
{
eckey_restart_ctx *rs_ctx;
if( ctx == NULL)
return;
rs_ctx = ctx;
mbedtls_ecdsa_restart_free( &rs_ctx->ecdsa_rs );
mbedtls_ecdsa_free( &rs_ctx->ecdsa_ctx );
mbedtls_free( ctx );
}
static int eckey_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len,
void *rs_ctx )
{
int ret;
eckey_restart_ctx *rs = rs_ctx;
/* Should never happen */
if( rs == NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
/* set up our own sub-context if needed (that is, on first run) */
if( rs->ecdsa_ctx.grp.pbits == 0 )
MBEDTLS_MPI_CHK( mbedtls_ecdsa_from_keypair( &rs->ecdsa_ctx, ctx ) );
MBEDTLS_MPI_CHK( ecdsa_verify_rs_wrap( &rs->ecdsa_ctx,
md_alg, hash, hash_len,
sig, sig_len, &rs->ecdsa_rs ) );
cleanup:
return( ret );
}
static int eckey_sign_rs_wrap( void *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,
void *rs_ctx )
{
int ret;
eckey_restart_ctx *rs = rs_ctx;
/* Should never happen */
if( rs == NULL )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
/* set up our own sub-context if needed (that is, on first run) */
if( rs->ecdsa_ctx.grp.pbits == 0 )
MBEDTLS_MPI_CHK( mbedtls_ecdsa_from_keypair( &rs->ecdsa_ctx, ctx ) );
MBEDTLS_MPI_CHK( ecdsa_sign_rs_wrap( &rs->ecdsa_ctx, md_alg,
hash, hash_len, sig, sig_len,
f_rng, p_rng, &rs->ecdsa_rs ) );
cleanup:
return( ret );
}
#endif /* MBEDTLS_ECP_RESTARTABLE */
#endif /* MBEDTLS_ECDSA_C */
static int eckey_check_pair( const void *pub, const void *prv )
{
return( mbedtls_ecp_check_pub_priv( (const mbedtls_ecp_keypair *) pub,
(const mbedtls_ecp_keypair *) prv ) );
}
static void *eckey_alloc_wrap( void )
{
void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );
if( ctx != NULL )
mbedtls_ecp_keypair_init( ctx );
return( ctx );
}
static void eckey_free_wrap( void *ctx )
{
mbedtls_ecp_keypair_free( (mbedtls_ecp_keypair *) ctx );
mbedtls_free( ctx );
}
static void eckey_debug( const void *ctx, mbedtls_pk_debug_item *items )
{
items->type = MBEDTLS_PK_DEBUG_ECP;
items->name = "eckey.Q";
items->value = &( ((mbedtls_ecp_keypair *) ctx)->Q );
}
const mbedtls_pk_info_t mbedtls_eckey_info = {
MBEDTLS_PK_ECKEY,
"EC",
eckey_get_bitlen,
eckey_can_do,
#if defined(MBEDTLS_ECDSA_C)
eckey_verify_wrap,
eckey_sign_wrap,
#if defined(MBEDTLS_ECP_RESTARTABLE)
eckey_verify_rs_wrap,
eckey_sign_rs_wrap,
#endif
#else /* MBEDTLS_ECDSA_C */
NULL,
NULL,
#endif /* MBEDTLS_ECDSA_C */
NULL,
NULL,
eckey_check_pair,
eckey_alloc_wrap,
eckey_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
eckey_rs_alloc,
eckey_rs_free,
#endif
eckey_debug,
};
/*
* EC key restricted to ECDH
*/
static int eckeydh_can_do( mbedtls_pk_type_t type )
{
return( type == MBEDTLS_PK_ECKEY ||
type == MBEDTLS_PK_ECKEY_DH );
}
const mbedtls_pk_info_t mbedtls_eckeydh_info = {
MBEDTLS_PK_ECKEY_DH,
"EC_DH",
eckey_get_bitlen, /* Same underlying key structure */
eckeydh_can_do,
NULL,
NULL,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
NULL,
NULL,
eckey_check_pair,
eckey_alloc_wrap, /* Same underlying key structure */
eckey_free_wrap, /* Same underlying key structure */
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
eckey_debug, /* Same underlying key structure */
};
#endif /* MBEDTLS_ECP_C */
#if defined(MBEDTLS_ECDSA_C)
static int ecdsa_can_do( mbedtls_pk_type_t type )
{
return( type == MBEDTLS_PK_ECDSA );
}
#if defined(MBEDTLS_USE_PSA_CRYPTO)
/*
* An ASN.1 encoded signature is a sequence of two ASN.1 integers. Parse one of
* those integers and convert it to the fixed-length encoding expected by PSA.
*/
static int extract_ecdsa_sig_int( unsigned char **from, const unsigned char *end,
unsigned char *to, size_t to_len )
{
int ret;
size_t unpadded_len, padding_len;
if( ( ret = mbedtls_asn1_get_tag( from, end, &unpadded_len,
MBEDTLS_ASN1_INTEGER ) ) != 0 )
{
return( ret );
}
while( unpadded_len > 0 && **from == 0x00 )
{
( *from )++;
unpadded_len--;
}
if( unpadded_len > to_len || unpadded_len == 0 )
return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
padding_len = to_len - unpadded_len;
memset( to, 0x00, padding_len );
memcpy( to + padding_len, *from, unpadded_len );
( *from ) += unpadded_len;
return( 0 );
}
/*
* Convert a signature from an ASN.1 sequence of two integers
* to a raw {r,s} buffer. Note: the provided sig buffer must be at least
* twice as big as int_size.
*/
static int extract_ecdsa_sig( unsigned char **p, const unsigned char *end,
unsigned char *sig, size_t int_size )
{
int ret;
size_t tmp_size;
if( ( ret = mbedtls_asn1_get_tag( p, end, &tmp_size,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( ret );
/* Extract r */
if( ( ret = extract_ecdsa_sig_int( p, end, sig, int_size ) ) != 0 )
return( ret );
/* Extract s */
if( ( ret = extract_ecdsa_sig_int( p, end, sig + int_size, int_size ) ) != 0 )
return( ret );
return( 0 );
}
static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len )
{
int ret;
psa_key_handle_t key_slot;
psa_key_policy_t policy;
psa_key_type_t psa_type;
mbedtls_pk_context key;
int key_len;
/* see ECP_PUB_DER_MAX_BYTES in pkwrite.c */
unsigned char buf[30 + 2 * MBEDTLS_ECP_MAX_BYTES];
unsigned char *p;
mbedtls_pk_info_t pk_info = mbedtls_eckey_info;
psa_algorithm_t psa_sig_md, psa_md;
psa_ecc_curve_t curve = mbedtls_psa_translate_ecc_group(
( (mbedtls_ecdsa_context *) ctx )->grp.id );
const size_t signature_part_size = ( ( (mbedtls_ecdsa_context *) ctx )->grp.nbits + 7 ) / 8;
if( curve == 0 )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
/* mbedlts_pk_write_pubkey_der() expects a full PK context,
* re-construct one to make it happy */
key.pk_info = &pk_info;
key.pk_ctx = ctx;
p = buf + sizeof( buf );
key_len = mbedtls_pk_write_pubkey( &p, buf, &key );
if( key_len <= 0 )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
psa_md = mbedtls_psa_translate_md( md_alg );
if( psa_md == 0 )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
psa_sig_md = PSA_ALG_ECDSA( psa_md );
psa_type = PSA_KEY_TYPE_ECC_PUBLIC_KEY( curve );
if( ( ret = psa_allocate_key( &key_slot ) ) != PSA_SUCCESS )
return( mbedtls_psa_err_translate_pk( ret ) );
policy = psa_key_policy_init();
psa_key_policy_set_usage( &policy, PSA_KEY_USAGE_VERIFY, psa_sig_md );
if( ( ret = psa_set_key_policy( key_slot, &policy ) ) != PSA_SUCCESS )
{
ret = mbedtls_psa_err_translate_pk( ret );
goto cleanup;
}
if( psa_import_key( key_slot, psa_type, buf + sizeof( buf ) - key_len, key_len )
!= PSA_SUCCESS )
{
ret = MBEDTLS_ERR_PK_BAD_INPUT_DATA;
goto cleanup;
}
/* We don't need the exported key anymore and can
* reuse its buffer for signature extraction. */
if( 2 * signature_part_size > sizeof( buf ) )
{
ret = MBEDTLS_ERR_PK_BAD_INPUT_DATA;
goto cleanup;
}
p = (unsigned char*) sig;
if( ( ret = extract_ecdsa_sig( &p, sig + sig_len, buf,
signature_part_size ) ) != 0 )
{
goto cleanup;
}
if( psa_asymmetric_verify( key_slot, psa_sig_md,
hash, hash_len,
buf, 2 * signature_part_size )
!= PSA_SUCCESS )
{
ret = MBEDTLS_ERR_ECP_VERIFY_FAILED;
goto cleanup;
}
if( p != sig + sig_len )
{
ret = MBEDTLS_ERR_PK_SIG_LEN_MISMATCH;
goto cleanup;
}
ret = 0;
cleanup:
psa_destroy_key( key_slot );
return( ret );
}
#else /* MBEDTLS_USE_PSA_CRYPTO */
static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len )
{
int ret;
((void) md_alg);
ret = mbedtls_ecdsa_read_signature( (mbedtls_ecdsa_context *) ctx,
hash, hash_len, sig, sig_len );
if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
return( ret );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
static int ecdsa_sign_wrap( void *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_ecdsa_write_signature( (mbedtls_ecdsa_context *) ctx,
md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng ) );
}
#if defined(MBEDTLS_ECP_RESTARTABLE)
static int ecdsa_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len,
void *rs_ctx )
{
int ret;
((void) md_alg);
ret = mbedtls_ecdsa_read_signature_restartable(
(mbedtls_ecdsa_context *) ctx,
hash, hash_len, sig, sig_len,
(mbedtls_ecdsa_restart_ctx *) rs_ctx );
if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
return( ret );
}
static int ecdsa_sign_rs_wrap( void *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,
void *rs_ctx )
{
return( mbedtls_ecdsa_write_signature_restartable(
(mbedtls_ecdsa_context *) ctx,
md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng,
(mbedtls_ecdsa_restart_ctx *) rs_ctx ) );
}
#endif /* MBEDTLS_ECP_RESTARTABLE */
static void *ecdsa_alloc_wrap( void )
{
void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_context ) );
if( ctx != NULL )
mbedtls_ecdsa_init( (mbedtls_ecdsa_context *) ctx );
return( ctx );
}
static void ecdsa_free_wrap( void *ctx )
{
mbedtls_ecdsa_free( (mbedtls_ecdsa_context *) ctx );
mbedtls_free( ctx );
}
#if defined(MBEDTLS_ECP_RESTARTABLE)
static void *ecdsa_rs_alloc( void )
{
void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_restart_ctx ) );
if( ctx != NULL )
mbedtls_ecdsa_restart_init( ctx );
return( ctx );
}
static void ecdsa_rs_free( void *ctx )
{
mbedtls_ecdsa_restart_free( ctx );
mbedtls_free( ctx );
}
#endif /* MBEDTLS_ECP_RESTARTABLE */
const mbedtls_pk_info_t mbedtls_ecdsa_info = {
MBEDTLS_PK_ECDSA,
"ECDSA",
eckey_get_bitlen, /* Compatible key structures */
ecdsa_can_do,
ecdsa_verify_wrap,
ecdsa_sign_wrap,
#if defined(MBEDTLS_ECP_RESTARTABLE)
ecdsa_verify_rs_wrap,
ecdsa_sign_rs_wrap,
#endif
NULL,
NULL,
eckey_check_pair, /* Compatible key structures */
ecdsa_alloc_wrap,
ecdsa_free_wrap,
#if defined(MBEDTLS_ECP_RESTARTABLE)
ecdsa_rs_alloc,
ecdsa_rs_free,
#endif
eckey_debug, /* Compatible key structures */
};
#endif /* MBEDTLS_ECDSA_C */
#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
/*
* Support for alternative RSA-private implementations
*/
static int rsa_alt_can_do( mbedtls_pk_type_t type )
{
return( type == MBEDTLS_PK_RSA );
}
static size_t rsa_alt_get_bitlen( const void *ctx )
{
const mbedtls_rsa_alt_context *rsa_alt = (const mbedtls_rsa_alt_context *) ctx;
return( 8 * rsa_alt->key_len_func( rsa_alt->key ) );
}
static int rsa_alt_sign_wrap( void *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_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
#if SIZE_MAX > UINT_MAX
if( UINT_MAX < hash_len )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
#endif /* SIZE_MAX > UINT_MAX */
*sig_len = rsa_alt->key_len_func( rsa_alt->key );
return( rsa_alt->sign_func( rsa_alt->key, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
md_alg, (unsigned int) hash_len, hash, sig ) );
}
static int rsa_alt_decrypt_wrap( void *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 )
{
mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
((void) f_rng);
((void) p_rng);
if( ilen != rsa_alt->key_len_func( rsa_alt->key ) )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
return( rsa_alt->decrypt_func( rsa_alt->key,
MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
}
#if defined(MBEDTLS_RSA_C)
static int rsa_alt_check_pair( const void *pub, const void *prv )
{
unsigned char sig[MBEDTLS_MPI_MAX_SIZE];
unsigned char hash[32];
size_t sig_len = 0;
int ret;
if( rsa_alt_get_bitlen( prv ) != rsa_get_bitlen( pub ) )
return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
memset( hash, 0x2a, sizeof( hash ) );
if( ( ret = rsa_alt_sign_wrap( (void *) prv, MBEDTLS_MD_NONE,
hash, sizeof( hash ),
sig, &sig_len, NULL, NULL ) ) != 0 )
{
return( ret );
}
if( rsa_verify_wrap( (void *) pub, MBEDTLS_MD_NONE,
hash, sizeof( hash ), sig, sig_len ) != 0 )
{
return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
}
return( 0 );
}
#endif /* MBEDTLS_RSA_C */
static void *rsa_alt_alloc_wrap( void )
{
void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_alt_context ) );
if( ctx != NULL )
memset( ctx, 0, sizeof( mbedtls_rsa_alt_context ) );
return( ctx );
}
static void rsa_alt_free_wrap( void *ctx )
{
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_rsa_alt_context ) );
mbedtls_free( ctx );
}
const mbedtls_pk_info_t mbedtls_rsa_alt_info = {
MBEDTLS_PK_RSA_ALT,
"RSA-alt",
rsa_alt_get_bitlen,
rsa_alt_can_do,
NULL,
rsa_alt_sign_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
rsa_alt_decrypt_wrap,
NULL,
#if defined(MBEDTLS_RSA_C)
rsa_alt_check_pair,
#else
NULL,
#endif
rsa_alt_alloc_wrap,
rsa_alt_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL,
NULL,
#endif
NULL,
};
#endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
#if defined(MBEDTLS_USE_PSA_CRYPTO)
static void *pk_opaque_alloc_wrap( void )
{
void *ctx = mbedtls_calloc( 1, sizeof( psa_key_handle_t ) );
/* no _init() function to call, an calloc() already zeroized */
return( ctx );
}
static void pk_opaque_free_wrap( void *ctx )
{
mbedtls_platform_zeroize( ctx, sizeof( psa_key_handle_t ) );
mbedtls_free( ctx );
}
static size_t pk_opaque_get_bitlen( const void *ctx )
{
const psa_key_handle_t *key = (const psa_key_handle_t *) ctx;
size_t bits;
if( PSA_SUCCESS != psa_get_key_information( *key, NULL, &bits ) )
return( 0 );
return( bits );
}
static int pk_opaque_can_do( mbedtls_pk_type_t type )
{
/* For now opaque PSA keys can only wrap ECC keypairs,
* as checked by setup_psa().
* Also, ECKEY_DH does not really make sense with the current API. */
return( type == MBEDTLS_PK_ECKEY ||
type == MBEDTLS_PK_ECDSA );
}
/*
* Simultaneously convert and move raw MPI from the beginning of a buffer
* to an ASN.1 MPI at the end of the buffer.
* See also mbedtls_asn1_write_mpi().
*
* p: pointer to the end of the output buffer
* start: start of the output buffer, and also of the mpi to write at the end
* n_len: length of the mpi to read from start
*/
static int asn1_write_mpibuf( unsigned char **p, unsigned char *start,
size_t n_len )
{
int ret;
size_t len = 0;
if( (size_t)( *p - start ) < n_len )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
len = n_len;
*p -= len;
memmove( *p, start, len );
/* ASN.1 DER encoding requires minimal length, so skip leading 0s.
* Neither r nor s should be 0, but as a failsafe measure, still detect
* that rather than overflowing the buffer in case of a PSA error. */
while( len > 0 && **p == 0x00 )
{
++(*p);
--len;
}
/* this is only reached if the signature was invalid */
if( len == 0 )
return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
/* if the msb is 1, ASN.1 requires that we prepend a 0.
* Neither r nor s can be 0, so we can assume len > 0 at all times. */
if( **p & 0x80 )
{
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = 0x00;
len += 1;
}
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
MBEDTLS_ASN1_INTEGER ) );
return( (int) len );
}
/* Transcode signature from PSA format to ASN.1 sequence.
* See ecdsa_signature_to_asn1 in ecdsa.c, but with byte buffers instead of
* MPIs, and in-place.
*
* [in/out] sig: the signature pre- and post-transcoding
* [in/out] sig_len: signature length pre- and post-transcoding
* [int] buf_len: the available size the in/out buffer
*/
static int pk_ecdsa_sig_asn1_from_psa( unsigned char *sig, size_t *sig_len,
size_t buf_len )
{
int ret;
size_t len = 0;
const size_t rs_len = *sig_len / 2;
unsigned char *p = sig + buf_len;
MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig + rs_len, rs_len ) );
MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig, rs_len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, sig, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, sig,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
memmove( sig, p, len );
*sig_len = len;
return( 0 );
}
static int pk_opaque_sign_wrap( void *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 )
{
const psa_key_handle_t *key = (const psa_key_handle_t *) ctx;
psa_algorithm_t alg = PSA_ALG_ECDSA( mbedtls_psa_translate_md( md_alg ) );
size_t bits, buf_len;
psa_status_t status;
/* PSA has its own RNG */
(void) f_rng;
(void) p_rng;
/* PSA needs an output buffer of known size, but our API doesn't provide
* that information. Assume that the buffer is large enough for a
* maximal-length signature with that key (otherwise the application is
* buggy anyway). */
status = psa_get_key_information( *key, NULL, &bits );
if( status != PSA_SUCCESS )
return( mbedtls_psa_err_translate_pk( status ) );
buf_len = MBEDTLS_ECDSA_MAX_SIG_LEN( bits );
/* make the signature */
status = psa_asymmetric_sign( *key, alg, hash, hash_len,
sig, buf_len, sig_len );
if( status != PSA_SUCCESS )
return( mbedtls_psa_err_translate_pk( status ) );
/* transcode it to ASN.1 sequence */
return( pk_ecdsa_sig_asn1_from_psa( sig, sig_len, buf_len ) );
}
const mbedtls_pk_info_t mbedtls_pk_opaque_info = {
MBEDTLS_PK_OPAQUE,
"Opaque",
pk_opaque_get_bitlen,
pk_opaque_can_do,
NULL, /* verify - will be done later */
pk_opaque_sign_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL, /* restartable verify - not relevant */
NULL, /* restartable sign - not relevant */
#endif
NULL, /* decrypt - will be done later */
NULL, /* encrypt - will be done later */
NULL, /* check_pair - could be done later or left NULL */
pk_opaque_alloc_wrap,
pk_opaque_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
NULL, /* restart alloc - not relevant */
NULL, /* restart free - not relevant */
#endif
NULL, /* debug - could be done later, or even left NULL */
};
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#endif /* MBEDTLS_PK_C */