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Merged
merged 4 commits into from
Feb 1, 2019
Merged

Make further adaptations to new EC public key format #41

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cd0f276
Update pointer in PSA-based mbedtls_pk_write_pubkey()
Feb 1, 2019
69777ca
Add function to find OID for PSA ECC curve identifiers
Feb 1, 2019
9acfd73
Adapt mbedtls_pk_write_pubkey_der() to the new PSA public key format
Feb 1, 2019
00114d7
Adapt test in test_suite_pk to work with new PSA public key format
Feb 1, 2019
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77 changes: 77 additions & 0 deletions include/mbedtls/psa_util.h
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Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,7 @@
#include "ecp.h"
#include "md.h"
#include "pk.h"
#include "oid.h"

/* Translations for symmetric crypto. */

Expand Down Expand Up @@ -155,6 +156,82 @@ static inline psa_algorithm_t mbedtls_psa_translate_md( mbedtls_md_type_t md_alg

/* Translations for ECC. */

static inline int mbedtls_psa_get_ecc_oid_from_id(
psa_ecc_curve_t curve, char const **oid, size_t *oid_len )
{
switch( curve )
{
#if defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED)
case PSA_ECC_CURVE_SECP192R1:
*oid = MBEDTLS_OID_EC_GRP_SECP192R1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP192R1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_SECP192R1_ENABLED */
#if defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED)
case PSA_ECC_CURVE_SECP224R1:
*oid = MBEDTLS_OID_EC_GRP_SECP224R1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP224R1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_SECP224R1_ENABLED */
#if defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
case PSA_ECC_CURVE_SECP256R1:
*oid = MBEDTLS_OID_EC_GRP_SECP256R1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP256R1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_SECP256R1_ENABLED */
#if defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED)
case PSA_ECC_CURVE_SECP384R1:
*oid = MBEDTLS_OID_EC_GRP_SECP384R1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP384R1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_SECP384R1_ENABLED */
#if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED)
case PSA_ECC_CURVE_SECP521R1:
*oid = MBEDTLS_OID_EC_GRP_SECP521R1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP521R1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_SECP521R1_ENABLED */
#if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
case PSA_ECC_CURVE_SECP192K1:
*oid = MBEDTLS_OID_EC_GRP_SECP192K1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP192K1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_SECP192K1_ENABLED */
#if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
case PSA_ECC_CURVE_SECP224K1:
*oid = MBEDTLS_OID_EC_GRP_SECP224K1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP224K1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_SECP224K1_ENABLED */
#if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
case PSA_ECC_CURVE_SECP256K1:
*oid = MBEDTLS_OID_EC_GRP_SECP256K1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_SECP256K1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_SECP256K1_ENABLED */
#if defined(MBEDTLS_ECP_DP_BP256R1_ENABLED)
case PSA_ECC_CURVE_BRAINPOOL_P256R1:
*oid = MBEDTLS_OID_EC_GRP_BP256R1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_BP256R1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_BP256R1_ENABLED */
#if defined(MBEDTLS_ECP_DP_BP384R1_ENABLED)
case PSA_ECC_CURVE_BRAINPOOL_P384R1:
*oid = MBEDTLS_OID_EC_GRP_BP384R1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_BP384R1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_BP384R1_ENABLED */
#if defined(MBEDTLS_ECP_DP_BP512R1_ENABLED)
case PSA_ECC_CURVE_BRAINPOOL_P512R1:
*oid = MBEDTLS_OID_EC_GRP_BP512R1;
*oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_BP512R1 );
return( 0 );
#endif /* MBEDTLS_ECP_DP_BP512R1_ENABLED */
}

return( -1 );
}

static inline psa_ecc_curve_t mbedtls_psa_translate_ecc_group( mbedtls_ecp_group_id grpid )
{
switch( grpid )
Expand Down
56 changes: 44 additions & 12 deletions library/pkwrite.c
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Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,7 @@

#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#include "mbedtls/psa_util.h"
#endif
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
Expand Down Expand Up @@ -181,7 +182,8 @@ int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
}
else
{
memmove( *p - len, start, len );
*p -= len;
memmove( *p, start, len );
}
}
else
Expand All @@ -196,16 +198,13 @@ int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, si
int ret;
unsigned char *c;
size_t len = 0, par_len = 0, oid_len;
mbedtls_pk_type_t pk_type;
const char *oid;

c = buf + size;

MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, key ) );

if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_OPAQUE )
{
return( (int) len );
}
if( c - buf < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );

Expand All @@ -220,18 +219,51 @@ int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, si
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_BIT_STRING ) );

if( ( ret = mbedtls_oid_get_oid_by_pk_alg( mbedtls_pk_get_type( key ),
&oid, &oid_len ) ) != 0 )
{
return( ret );
}

pk_type = mbedtls_pk_get_type( key );
#if defined(MBEDTLS_ECP_C)
if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
if( pk_type == MBEDTLS_PK_ECKEY )
{
MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, mbedtls_pk_ec( *key ) ) );
}
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( pk_type == MBEDTLS_PK_OPAQUE )
{
psa_status_t status;
psa_key_type_t key_type;
psa_key_handle_t handle;
psa_ecc_curve_t curve;

handle = *((psa_key_handle_t*) key->pk_ctx );

status = psa_get_key_information( handle, &key_type,
NULL /* bitsize not needed */ );
if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );

curve = PSA_KEY_TYPE_GET_CURVE( key_type );
if( curve == 0 )
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );

ret = mbedtls_psa_get_ecc_oid_from_id( curve, &oid, &oid_len );
if( ret != 0 )
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );

/* Write EC algorithm parameters; that's akin
* to pk_write_ec_param() above. */
MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_oid( &c, buf,
oid, oid_len ) );

/* The rest of the function works as for legacy EC contexts. */
pk_type = MBEDTLS_PK_ECKEY;
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */

if( ( ret = mbedtls_oid_get_oid_by_pk_alg( pk_type, &oid,
&oid_len ) ) != 0 )
{
return( ret );
}

MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, buf, oid, oid_len,
par_len ) );
Expand Down
57 changes: 39 additions & 18 deletions tests/suites/test_suite_pk.function
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Original file line number Diff line number Diff line change
Expand Up @@ -778,44 +778,65 @@ exit:
void pk_psa_sign( )
{
mbedtls_pk_context pk;
psa_key_handle_t key;
unsigned char hash[50], sig[100], pkey[100];
size_t sig_len, klen = 0;
unsigned char hash[50], sig[100], pkey_legacy[100], pkey_psa[100];
unsigned char *pkey_legacy_start, *pkey_psa_start;
size_t sig_len, klen_legacy, klen_psa;
int ret;
psa_key_handle_t handle;

/*
* This tests making signatures with a wrapped PSA key:
* - generate a fresh PSA key
* - generate a fresh ECP legacy PK context
* - wrap it in a PK context and make a signature this way
* - extract the public key
* - parse it to a PK context and verify the signature this way
*/

/* Create legacy EC public/private key in PK context. */
mbedtls_pk_init( &pk );
TEST_ASSERT( mbedtls_pk_setup( &pk,
mbedtls_pk_info_from_type( MBEDTLS_PK_ECKEY ) ) == 0 );
TEST_ASSERT( mbedtls_ecp_gen_key( MBEDTLS_ECP_DP_SECP256R1,
(mbedtls_ecp_keypair*) pk.pk_ctx,
rnd_std_rand, NULL ) == 0 );

/* Export underlying public key for re-importing in a legacy context. */
ret = mbedtls_pk_write_pubkey_der( &pk, pkey_legacy,
sizeof( pkey_legacy ) );
TEST_ASSERT( ret >= 0 );
klen_legacy = (size_t) ret;
/* mbedtls_pk_write_pubkey_der() writes backwards in the data buffer. */
pkey_legacy_start = pkey_legacy + sizeof( pkey_legacy ) - klen_legacy;

/* Turn PK context into an opaque one. */
TEST_ASSERT( psa_allocate_key( &handle ) == PSA_SUCCESS );
TEST_ASSERT( mbedtls_pk_wrap_as_opaque( &pk, &handle,
PSA_ALG_SHA_256 ) == 0 );

memset( hash, 0x2a, sizeof hash );
memset( sig, 0, sizeof sig );
memset( pkey, 0, sizeof pkey );

key = pk_psa_genkey();
TEST_ASSERT( key != 0 );

TEST_ASSERT( mbedtls_pk_setup_opaque( &pk, key ) == 0 );

TEST_ASSERT( mbedtls_pk_sign( &pk, MBEDTLS_MD_SHA256,
hash, sizeof hash, sig, &sig_len,
NULL, NULL ) == 0 );

mbedtls_pk_free( &pk );

TEST_ASSERT( PSA_SUCCESS == psa_export_public_key(
key, pkey, sizeof( pkey ), &klen ) );
TEST_ASSERT( PSA_SUCCESS == psa_destroy_key( key ) );
/* Export underlying public key for re-importing in a psa context. */
ret = mbedtls_pk_write_pubkey_der( &pk, pkey_psa,
sizeof( pkey_psa ) );
TEST_ASSERT( ret >= 0 );
klen_psa = (size_t) ret;
/* mbedtls_pk_write_pubkey_der() writes backwards in the data buffer. */
pkey_psa_start = pkey_psa + sizeof( pkey_psa ) - klen_psa;

mbedtls_pk_init( &pk );

TEST_ASSERT( mbedtls_pk_parse_public_key( &pk, pkey, klen ) == 0 );
TEST_ASSERT( klen_psa == klen_legacy );
TEST_ASSERT( memcmp( pkey_psa_start, pkey_legacy_start, klen_psa ) == 0 );

mbedtls_pk_free( &pk );
TEST_ASSERT( PSA_SUCCESS == psa_destroy_key( handle ) );

mbedtls_pk_init( &pk );
TEST_ASSERT( mbedtls_pk_parse_public_key( &pk, pkey_legacy_start,
klen_legacy ) == 0 );
TEST_ASSERT( mbedtls_pk_verify( &pk, MBEDTLS_MD_SHA256,
hash, sizeof hash, sig, sig_len ) == 0 );

Expand Down