/*
* Public Key abstraction layer: wrapper functions
*
* Copyright (C) 2006-2020, 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"
#include "mbedtls/error.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_ERR_ERROR_CORRUPTION_DETECTED;
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_ERR_ERROR_CORRUPTION_DETECTED;
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_ERR_ERROR_CORRUPTION_DETECTED;
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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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_arg, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
const unsigned char *sig, size_t sig_len )
{
mbedtls_ecdsa_context *ctx = ctx_arg;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_key_handle_t key_handle = 0;
psa_status_t status;
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;
size_t curve_bits;
psa_ecc_curve_t curve;
#if TARGET_TFM
curve = mbedtls_ecp_curve_info_from_grp_id( ctx->grp.id )->tls_id;
#else
curve = mbedtls_ecc_group_to_psa( ctx->grp.id, &curve_bits );
#endif
const size_t signature_part_size = ( ctx->grp.nbits + 7 ) / 8;
if( curve == 0 )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
/* mbedtls_pk_write_pubkey() 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_set_key_type( &attributes, PSA_KEY_TYPE_ECC_PUBLIC_KEY( curve ) );
psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_VERIFY_HASH );
psa_set_key_algorithm( &attributes, psa_sig_md );
status = psa_import_key( &attributes,
buf + sizeof( buf ) - key_len, key_len,
&key_handle );
if( status != PSA_SUCCESS )
{
ret = mbedtls_psa_err_translate_pk( status );
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_verify_hash( key_handle, 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_handle );
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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
((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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
((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 );
if( *sig_len > MBEDTLS_PK_SIGNATURE_MAX_SIZE )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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;
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
if( PSA_SUCCESS != psa_get_key_attributes( *key, &attributes ) )
return( 0 );
bits = psa_get_key_bits( &attributes );
psa_reset_key_attributes( &attributes );
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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_algorithm_t alg = PSA_ALG_ECDSA( mbedtls_psa_translate_md( md_alg ) );
size_t 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_attributes( *key, &attributes );
if( status != PSA_SUCCESS )
return( mbedtls_psa_err_translate_pk( status ) );
buf_len = MBEDTLS_ECDSA_MAX_SIG_LEN( psa_get_key_bits( &attributes ) );
psa_reset_key_attributes( &attributes );
if( buf_len > MBEDTLS_PK_SIGNATURE_MAX_SIZE )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
/* make the signature */
status = psa_sign_hash( *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 */
