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_non_psa.c b/programs/psa/hmac_non_psa.c
new file mode 100644
index 0000000..c7ced7c
--- /dev/null
+++ b/programs/psa/hmac_non_psa.c
@@ -0,0 +1,113 @@
+/*
+ * 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