mbedtls/programs/psa/hmac_non_psa.c
Manuel Pégourié-Gonnard edf6e83cbc Split hmac_md_psa.c
Having two programs might make comparison easier, and will make it
easier to people to use just the PSA one as an example.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2022-01-27 12:36:39 +01:00

114 lines
3.3 KiB
C

/*
* This is a companion to hmac_psa.c, doing the same operations with the
* legacy MD API. The goal is that comparing the two programs will help people
* migrating to the PSA Crypto API.
*
* Copyright The Mbed TLS Contributors
* 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.
*/
/*
* When in comes to multi-part HMAC operations, the `mbedtls_md_context`
* serves a dual purpose (1) hold the key, and (2) save progress information
* for the current operation. With PSA those roles are held by two disinct
* objects: (1) a psa_key_id_t to hold the key, and (2) a psa_operation_t for
* multi-part progress.
*
* This program and its companion hmac_psa.c illustrate this by doing the
* same sequence of multi-part HMAC computation with both APIs; looking at the
* two side by side should make the differences and similarities clear.
*/
#include <stdio.h>
#include "mbedtls/build_info.h"
#if !defined(MBEDTLS_MD_C)
int main( void )
{
printf( "MBEDTLS_MD_C not defined\r\n" );
return( 0 );
}
#else
#include "mbedtls/md.h"
/*
* Dummy inputs for HMAC
*/
const unsigned char msg1_part1[] = { 0x01, 0x02 };
const unsigned char msg1_part2[] = { 0x03, 0x04 };
const unsigned char msg2_part1[] = { 0x05, 0x05 };
const unsigned char msg2_part2[] = { 0x06, 0x06 };
const unsigned char key_bytes[32] = { 0 };
unsigned char out[32];
void print_out( const char *title )
{
printf( "%s:", title );
for( size_t i = 0; i < sizeof( out ); i++ )
printf( " %02x", out[i] );
printf( "\n" );
}
#define CHK( code ) \
do { \
ret = code; \
if( ret != 0 ) \
goto exit; \
} while( 0 )
int hmac_demo(void)
{
int ret;
mbedtls_md_context_t ctx;
mbedtls_md_init( &ctx );
/* prepare context and load key */
CHK( mbedtls_md_setup( &ctx, mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ), 1 ) );
CHK( mbedtls_md_hmac_starts( &ctx, key_bytes, sizeof( key_bytes ) ) );
/* compute HMAC(key, msg1_part1 | msg1_part2) */
CHK( mbedtls_md_hmac_update( &ctx, msg1_part1, sizeof( msg1_part1 ) ) );
CHK( mbedtls_md_hmac_update( &ctx, msg1_part2, sizeof( msg1_part2 ) ) );
CHK( mbedtls_md_hmac_finish( &ctx, out ) );
print_out( "msg1" );
/* compute HMAC(key, msg2_part1 | msg2_part2) */
CHK( mbedtls_md_hmac_reset( &ctx ) ); // prepare for new operation
CHK( mbedtls_md_hmac_update( &ctx, msg2_part1, sizeof( msg2_part1 ) ) );
CHK( mbedtls_md_hmac_update( &ctx, msg2_part2, sizeof( msg2_part2 ) ) );
CHK( mbedtls_md_hmac_finish( &ctx, out ) );
print_out( "msg2" );
exit:
mbedtls_md_free( &ctx );
return( ret );
}
int main(void)
{
int ret = hmac_demo();
if( ret != 0 )
printf( "ret = %d (-0x%04x)\n", ret, (unsigned) -ret );
}
#endif