Split aead_cipher_psa
Same as previous commit
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/programs/psa/aead_psa.c b/programs/psa/aead_psa.c
new file mode 100644
index 0000000..ebc7cd9
--- /dev/null
+++ b/programs/psa/aead_psa.c
@@ -0,0 +1,240 @@
+/*
+ * This is a simple example of multi-part AEAD computation using the PSA
+ * Crypto API. It comes with a companion program aead_non_psa.c, which does
+ * the same operations with the legacy Cipher 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 used with multi-part AEAD operations, the `mbedtls_cipher_context`
+ * serves a triple purpose (1) hold the key, (2) store the algorithm when no
+ * operation is active, and (3) save progress information for the current
+ * operation. With PSA those roles are held by disinct objects: (1) a
+ * psa_key_id_t to hold the key, a (2) psa_algorithm_t to represent the
+ * algorithm, and (3) a psa_operation_t for multi-part progress.
+ *
+ * On the other hand, with PSA, the algorithms encodes the desired tag length;
+ * with Cipher the desired tag length needs to be tracked separately.
+ *
+ * This program and its compation aead_non_psa.c illustrate this by doing the
+ * same sequence of multi-part AEAD 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_AES_C) || !defined(MBEDTLS_GCM_C) || \
+ !defined(MBEDTLS_CHACHAPOLY_C) || \
+ defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER)
+int main( void )
+{
+ printf( "MBEDTLS_PSA_CRYPTO_C and/or "
+ "MBEDTLS_AES_C and/or MBEDTLS_GCM_C and/or "
+ "MBEDTLS_CHACHAPOLY_C not defined, and/or "
+ "MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER defined\r\n" );
+ return( 0 );
+}
+#else
+
+#include <string.h>
+
+#include "psa/crypto.h"
+
+/*
+ * Dummy data and helper functions
+ */
+const char usage[] = "Usage: aead_psa [aes128-gcm|aes256-gcm|aes128-gcm_8|chachapoly]";
+
+const unsigned char iv1[12] = { 0x00 };
+const unsigned char add_data1[] = { 0x01, 0x02 };
+const unsigned char msg1_part1[] = { 0x03, 0x04 };
+const unsigned char msg1_part2[] = { 0x05, 0x06, 0x07 };
+const size_t msg1_size = sizeof( msg1_part1 ) + sizeof( msg1_part2 );
+
+const unsigned char iv2[12] = { 0x10 };
+const unsigned char add_data2[] = { 0x11, 0x12 };
+const unsigned char msg2_part1[] = { 0x13, 0x14 };
+const unsigned char msg2_part2[] = { 0x15, 0x16, 0x17 };
+const size_t msg2_size = sizeof( msg2_part1 ) + sizeof( msg2_part2 );
+
+const size_t msg_max_size = msg1_size > msg2_size ? msg1_size : msg2_size;
+
+const unsigned char key_bytes[32] = { 0x2a };
+
+void print_out( const char *title, unsigned char *out, size_t len )
+{
+ printf( "%s:", title );
+ for( size_t i = 0; i < len; i++ )
+ printf( " %02x", out[i] );
+ printf( "\n" );
+}
+
+#define CHK( code ) \
+ do { \
+ status = code; \
+ if( status != PSA_SUCCESS ) { \
+ printf( "%03d: status = %d\n", __LINE__, status ); \
+ goto exit; \
+ } \
+ } while( 0 )
+
+static psa_status_t aead_prepare( const char *info,
+ psa_key_id_t *key,
+ psa_algorithm_t *alg )
+{
+ psa_status_t status;
+
+ size_t key_bits;
+ psa_key_type_t key_type;
+ if( strcmp( info, "aes128-gcm" ) == 0 ) {
+ *alg = PSA_ALG_GCM;
+ key_bits = 128;
+ key_type = PSA_KEY_TYPE_AES;
+ } else if( strcmp( info, "aes256-gcm" ) == 0 ) {
+ *alg = PSA_ALG_GCM;
+ key_bits = 256;
+ key_type = PSA_KEY_TYPE_AES;
+ } else if( strcmp( info, "aes128-gcm_8" ) == 0 ) {
+ *alg = PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 8);
+ key_bits = 128;
+ key_type = PSA_KEY_TYPE_AES;
+ } else if( strcmp( info, "chachapoly" ) == 0 ) {
+ *alg = PSA_ALG_CHACHA20_POLY1305;
+ key_bits = 256;
+ key_type = PSA_KEY_TYPE_CHACHA20;
+ } else {
+ puts( usage );
+ return( PSA_ERROR_INVALID_ARGUMENT );
+ }
+
+ psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+ psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_ENCRYPT );
+ psa_set_key_algorithm( &attributes, *alg );
+ psa_set_key_type( &attributes, key_type );
+ psa_set_key_bits( &attributes, key_bits );
+
+ CHK( psa_import_key( &attributes, key_bytes, key_bits / 8, key ) );
+
+exit:
+ return( status );
+}
+
+static void aead_info( psa_key_id_t key, psa_algorithm_t alg )
+{
+ psa_key_attributes_t attr = PSA_KEY_ATTRIBUTES_INIT;
+ (void) psa_get_key_attributes( key, &attr );
+ psa_key_type_t key_type = psa_get_key_type( &attr );
+ size_t key_bits = psa_get_key_bits( &attr );
+ psa_algorithm_t base_alg = PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG( alg );
+ size_t tag_len = PSA_AEAD_TAG_LENGTH( key_type, key_bits, alg );
+
+ const char *type_str = key_type == PSA_KEY_TYPE_AES ? "AES"
+ : key_type == PSA_KEY_TYPE_CHACHA20 ? "Chacha"
+ : "???";
+ const char *base_str = base_alg == PSA_ALG_GCM ? "GCM"
+ : base_alg == PSA_ALG_CHACHA20_POLY1305 ? "ChachaPoly"
+ : "???";
+
+ printf( "%s, %u, %s, %u\n",
+ type_str, (unsigned) key_bits, base_str, (unsigned) tag_len );
+}
+
+static int aead_encrypt( psa_key_id_t key, psa_algorithm_t alg,
+ const unsigned char *iv, size_t iv_len,
+ const unsigned char *ad, size_t ad_len,
+ const unsigned char *pa, size_t pa_len,
+ const unsigned char *pb, size_t pb_len )
+{
+ psa_status_t status;
+ size_t olen, olen_tag;
+ unsigned char out[PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(msg_max_size)];
+ unsigned char *p = out, *end = out + sizeof( out );
+ unsigned char tag[PSA_AEAD_TAG_MAX_SIZE];
+
+ psa_aead_operation_t op = PSA_AEAD_OPERATION_INIT;
+ CHK( psa_aead_encrypt_setup( &op, key, alg ) );
+
+ CHK( psa_aead_set_nonce( &op, iv, iv_len ) );
+ CHK( psa_aead_update_ad( &op, ad, ad_len ) );
+ CHK( psa_aead_update( &op, pa, pa_len, p, end - p, &olen ) );
+ p += olen;
+ CHK( psa_aead_update( &op, pb, pb_len, p, end - p, &olen ) );
+ p += olen;
+ CHK( psa_aead_finish( &op, p, end - p, &olen,
+ tag, sizeof( tag ), &olen_tag ) );
+ p += olen;
+ memcpy( p, tag, olen_tag );
+ p += olen_tag;
+
+ olen = p - out;
+ print_out( "out", out, olen );
+
+exit:
+ /* required on errors, harmless on success */
+ psa_aead_abort( &op );
+ return( status );
+}
+
+static psa_status_t aead_demo( const char *info )
+{
+ psa_status_t status;
+
+ psa_key_id_t key;
+ psa_algorithm_t alg;
+
+ CHK( aead_prepare( info, &key, &alg ) );
+
+ aead_info( key, alg );
+
+ CHK( aead_encrypt( key, alg,
+ iv1, sizeof( iv1 ), add_data1, sizeof( add_data1 ),
+ msg1_part1, sizeof( msg1_part1 ),
+ msg1_part2, sizeof( msg1_part2 ) ) );
+ CHK( aead_encrypt( key, alg,
+ iv2, sizeof( iv2 ), add_data2, sizeof( add_data2 ),
+ msg2_part1, sizeof( msg2_part1 ),
+ msg2_part2, sizeof( msg2_part2 ) ) );
+
+exit:
+ psa_destroy_key( key );
+
+ return( status );
+}
+
+/*
+ * Main function
+ */
+int main( int argc, char **argv )
+{
+ if( argc != 2 )
+ {
+ puts( usage );
+ return( 1 );
+ }
+
+ psa_status_t status = psa_crypto_init();
+ if( status != PSA_SUCCESS )
+ printf( "psa init: %d\n", status );
+
+ aead_demo( argv[1] );
+}
+
+#endif