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>
diff --git a/programs/psa/hmac_psa.c b/programs/psa/hmac_psa.c
new file mode 100644
index 0000000..019b7ff
--- /dev/null
+++ b/programs/psa/hmac_psa.c
@@ -0,0 +1,131 @@
+/*
+ * This is a simple example of multi-part HMAC computation using the PSA
+ * Crypto API. It comes with a companion program hmac_non_psa.c, which does
+ * 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_non_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_PSA_CRYPTO_C) || \
+ defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER)
+int main( void )
+{
+ printf( "MBEDTLS_PSA_CRYPTO_C not defined, "
+ "and/or MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER defined\r\n" );
+ return( 0 );
+}
+#else
+
+#include "psa/crypto.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 { \
+ status = code; \
+ if( status != PSA_SUCCESS ) \
+ goto exit; \
+ } while( 0 )
+
+psa_status_t hmac_demo(void)
+{
+ psa_status_t status;
+ psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+ psa_key_id_t key = 0;
+ psa_algorithm_t alg = PSA_ALG_HMAC(PSA_ALG_SHA_256);
+
+ /* prepare key */
+ psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_SIGN_MESSAGE );
+ psa_set_key_algorithm( &attributes, alg );
+ psa_set_key_type( &attributes, PSA_KEY_TYPE_HMAC );
+ psa_set_key_bits( &attributes, 8 * sizeof( key_bytes ) );
+
+ status = psa_import_key( &attributes, key_bytes, sizeof( key_bytes ), &key );
+ if( status != PSA_SUCCESS )
+ return( status );
+
+ /* prepare operation */
+ psa_mac_operation_t op = PSA_MAC_OPERATION_INIT;
+ size_t out_len = 0;
+
+ /* compute HMAC(key, msg1_part1 | msg1_part2) */
+ CHK( psa_mac_sign_setup( &op, key, alg ) );
+ CHK( psa_mac_update( &op, msg1_part1, sizeof( msg1_part1 ) ) );
+ CHK( psa_mac_update( &op, msg1_part2, sizeof( msg1_part2 ) ) );
+ CHK( psa_mac_sign_finish( &op, out, sizeof( out ), &out_len ) );
+ print_out( "msg1" );
+
+ /* compute HMAC(key, msg2_part1 | msg2_part2) */
+ CHK( psa_mac_sign_setup( &op, key, alg ) );
+ CHK( psa_mac_update( &op, msg2_part1, sizeof( msg2_part1 ) ) );
+ CHK( psa_mac_update( &op, msg2_part2, sizeof( msg2_part2 ) ) );
+ CHK( psa_mac_sign_finish( &op, out, sizeof( out ), &out_len ) );
+ print_out( "msg2" );
+
+exit:
+ psa_mac_abort( &op );
+ psa_destroy_key( key );
+
+ return( status );
+}
+
+int main(void)
+{
+ psa_status_t status = psa_crypto_init();
+ if( status != PSA_SUCCESS )
+ printf( "psa init: %d\n", status );
+
+ status = hmac_demo();
+ if( status != PSA_SUCCESS )
+ printf( "hmac_demo: %d\n", status );
+}
+
+#endif