pk_wrap.c: add support for ecdsa signature verification using PSA

Use PSA internally to verify signatures.
Add a conversion to a raw signature format.
This commit is contained in:
Andrzej Kurek 2018-10-31 05:16:46 -04:00
parent e10f191543
commit 8b036a6082

View File

@ -45,6 +45,12 @@
#include "mbedtls/platform_util.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#include "mbedtls/x509.h"
#include "mbedtls/asn1.h"
#endif
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
@ -472,6 +478,259 @@ static int ecdsa_can_do( mbedtls_pk_type_t type )
return( type == MBEDTLS_PK_ECDSA );
}
#if defined(MBEDTLS_USE_PSA_CRYPTO)
static psa_status_t mbedtls_psa_get_free_key_slot( psa_key_slot_t *key )
{
for( psa_key_slot_t slot = 1; slot <= 32; slot++ )
{
if( psa_get_key_information( slot, NULL, NULL ) == PSA_ERROR_EMPTY_SLOT )
{
*key = slot;
return( PSA_SUCCESS );
}
}
return( PSA_ERROR_INSUFFICIENT_MEMORY );
}
static psa_algorithm_t translate_md_to_psa( mbedtls_md_type_t md_alg )
{
switch( md_alg )
{
#if defined(MBEDTLS_MD2_C)
case MBEDTLS_MD_MD2:
return( PSA_ALG_MD2 );
#endif
#if defined(MBEDTLS_MD4_C)
case MBEDTLS_MD_MD4:
return( PSA_ALG_MD4 );
#endif
#if defined(MBEDTLS_MD5_C)
case MBEDTLS_MD_MD5:
return( PSA_ALG_MD5 );
#endif
#if defined(MBEDTLS_SHA1_C)
case MBEDTLS_MD_SHA1:
return( PSA_ALG_SHA_1 );
#endif
#if defined(MBEDTLS_SHA256_C)
case MBEDTLS_MD_SHA224:
return( PSA_ALG_SHA_224 );
case MBEDTLS_MD_SHA256:
return( PSA_ALG_SHA_256 );
#endif
#if defined(MBEDTLS_SHA512_C)
case MBEDTLS_MD_SHA384:
return( PSA_ALG_SHA_384 );
case MBEDTLS_MD_SHA512:
return( PSA_ALG_SHA_512 );
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case MBEDTLS_MD_RIPEMD160:
return( PSA_ALG_RIPEMD160 );
#endif
case MBEDTLS_MD_NONE: // Intentional fallthrough
default:
return( 0 );
}
}
/*
* Convert a signature from an ASN.1 sequence of two integers
* to a raw {r,s} buffer. Note: upon a successful call, the caller
* takes ownership of the sig->p buffer.
*/
static int extract_ecdsa_sig( unsigned char **p, const unsigned char *end,
mbedtls_asn1_buf *sig )
{
int ret;
size_t len_signature;
size_t len_partial;
int tag_type;
if( ( end - *p ) < 1 )
return( MBEDTLS_ERR_X509_INVALID_SIGNATURE +
MBEDTLS_ERR_ASN1_OUT_OF_DATA );
tag_type = **p;
if( ( ret = mbedtls_asn1_get_tag(p, end, &len_partial,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) {
return( MBEDTLS_ERR_X509_INVALID_SIGNATURE + ret );
}
if( ( ret = mbedtls_asn1_get_tag( p, end, &len_partial, MBEDTLS_ASN1_INTEGER ) )
!= 0 )
return( ret );
if( **p == '\0' ) {
( *p )++;
len_partial--;
}
sig->p = mbedtls_calloc( 2, len_partial );
if( sig->p == NULL ) {
return( MBEDTLS_ERR_ASN1_ALLOC_FAILED );
}
memcpy( sig->p, *p, len_partial );
len_signature = len_partial;
( *p ) += len_partial;
if( ( ret = mbedtls_asn1_get_tag( p, end, &len_partial, MBEDTLS_ASN1_INTEGER ) )
!= 0 )
{
mbedtls_free( sig->p );
return( ret );
}
if( **p == '\0' ) {
( *p )++;
len_partial--;
}
memcpy( sig->p + len_partial, *p, len_partial );
len_signature += len_partial;
sig->tag = tag_type;
sig->len = len_signature;
( *p ) += len_partial;
return( 0 );
}
static psa_ecc_curve_t mbedtls_ecc_group_to_psa( mbedtls_ecp_group_id grpid )
{
switch( grpid )
{
#if defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED)
case MBEDTLS_ECP_DP_SECP192R1:
return( PSA_ECC_CURVE_SECP192R1 );
#endif
#if defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED)
case MBEDTLS_ECP_DP_SECP224R1:
return( PSA_ECC_CURVE_SECP224R1 );
#endif
#if defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
case MBEDTLS_ECP_DP_SECP256R1:
return( PSA_ECC_CURVE_SECP256R1 );
#endif
#if defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED)
case MBEDTLS_ECP_DP_SECP384R1:
return( PSA_ECC_CURVE_SECP384R1 );
#endif
#if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED)
case MBEDTLS_ECP_DP_SECP521R1:
return( PSA_ECC_CURVE_SECP521R1 );
#endif
#if defined(MBEDTLS_ECP_DP_BP256R1_ENABLED)
case MBEDTLS_ECP_DP_BP256R1:
return( PSA_ECC_CURVE_BRAINPOOL_P256R1 );
#endif
#if defined(MBEDTLS_ECP_DP_BP384R1_ENABLED)
case MBEDTLS_ECP_DP_BP384R1:
return( PSA_ECC_CURVE_BRAINPOOL_P384R1 );
#endif
#if defined(MBEDTLS_ECP_DP_BP512R1_ENABLED)
case MBEDTLS_ECP_DP_BP512R1:
return( PSA_ECC_CURVE_BRAINPOOL_P512R1 );
#endif
#if defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED)
case MBEDTLS_ECP_DP_CURVE25519:
return( PSA_ECC_CURVE_CURVE25519 );
#endif
#if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
case MBEDTLS_ECP_DP_SECP192K1:
return( PSA_ECC_CURVE_SECP192K1 );
#endif
#if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
case MBEDTLS_ECP_DP_SECP224K1:
return( PSA_ECC_CURVE_SECP224K1 );
#endif
#if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
case MBEDTLS_ECP_DP_SECP256K1:
return( PSA_ECC_CURVE_SECP256K1 );
#endif
#if defined(MBEDTLS_ECP_DP_CURVE448_ENABLED)
case MBEDTLS_ECP_DP_CURVE448:
return( PSA_ECC_CURVE_CURVE448 );
#endif
default:
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_slot_t key_slot;
psa_key_policy_t policy;
psa_key_type_t psa_type;
mbedtls_pk_context key;
mbedtls_asn1_buf signature;
int key_len;
const int buff_len = 30 + 2 * MBEDTLS_ECP_MAX_BYTES; // Equivalent of ECP_PUB_DER_MAX_BYTES
unsigned char buf[buff_len];
unsigned char *p = ( unsigned char* ) sig;
mbedtls_pk_info_t pk_info = mbedtls_eckey_info;
psa_algorithm_t psa_sig_md = PSA_ALG_ECDSA( translate_md_to_psa( md_alg ) );
psa_ecc_curve_t curve = mbedtls_ecc_group_to_psa ( ( (mbedtls_ecdsa_context *) ctx )->grp.id );
((void) md_alg);
memset( &signature, 0, sizeof( mbedtls_asn1_buf ) );
mbedtls_platform_zeroize( buf, buff_len );
key.pk_info = &pk_info;
key.pk_ctx = ctx;
psa_crypto_init();
psa_type = PSA_KEY_TYPE_ECC_PUBLIC_KEY( curve );
if( extract_ecdsa_sig( &p, p + sig_len, &signature ) != 0 )
{
ret = MBEDTLS_ERR_PK_BAD_INPUT_DATA;
goto cleanup;
}
key_len = mbedtls_pk_write_pubkey_der( &key, buf, buff_len );
if( key_len <= 0 )
{
ret = MBEDTLS_ERR_PK_BAD_INPUT_DATA;
goto cleanup;
}
if( mbedtls_psa_get_free_key_slot( &key_slot ) != PSA_SUCCESS )
{
ret = MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
goto cleanup;
}
psa_key_policy_init( &policy );
psa_key_policy_set_usage( &policy, PSA_KEY_USAGE_VERIFY, psa_sig_md );
if( psa_set_key_policy( key_slot, &policy ) != PSA_SUCCESS )
{
ret = MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
goto cleanup;
}
if( psa_import_key( key_slot, psa_type, buf+buff_len-key_len, key_len )
!= PSA_SUCCESS )
{
ret = MBEDTLS_ERR_PK_BAD_INPUT_DATA;
goto cleanup;
}
if( psa_asymmetric_verify( key_slot, psa_sig_md,
hash, hash_len,
signature.p, signature.len )
!= PSA_SUCCESS )
{
psa_destroy_key( key_slot );
ret = MBEDTLS_ERR_ECP_VERIFY_FAILED;
goto cleanup;
}
ret = 0;
psa_destroy_key( key_slot );
cleanup:
mbedtls_free( signature.p );
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 )
@ -487,6 +746,7 @@ static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
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,