* try to import mbedtls and build it * add stubs socket class * some boilterplate, read and write function implemented * more boilterplate / current error in handshake because no CA cert is setup * add something so skip ca verification, can ws curl https://google.com ! * cleanup / close implemented * tweak CMakefiles * typo in include * update readme * disable unittests
		
			
				
	
	
		
			717 lines
		
	
	
		
			26 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			717 lines
		
	
	
		
			26 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /**
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|  * PSA API key derivation demonstration
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|  *
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|  * This program calculates a key ladder: a chain of secret material, each
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|  * derived from the previous one in a deterministic way based on a label.
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|  * Two keys are identical if and only if they are derived from the same key
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|  * using the same label.
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|  *
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|  * The initial key is called the master key. The master key is normally
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|  * randomly generated, but it could itself be derived from another key.
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|  *
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|  * This program derives a series of keys called intermediate keys.
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|  * The first intermediate key is derived from the master key using the
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|  * first label passed on the command line. Each subsequent intermediate
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|  * key is derived from the previous one using the next label passed
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|  * on the command line.
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|  *
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|  * This program has four modes of operation:
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|  *
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|  * - "generate": generate a random master key.
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|  * - "wrap": derive a wrapping key from the last intermediate key,
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|  *           and use that key to encrypt-and-authenticate some data.
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|  * - "unwrap": derive a wrapping key from the last intermediate key,
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|  *             and use that key to decrypt-and-authenticate some
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|  *             ciphertext created by wrap mode.
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|  * - "save": save the last intermediate key so that it can be reused as
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|  *           the master key in another run of the program.
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|  *
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|  * See the usage() output for the command line usage. See the file
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|  * `key_ladder_demo.sh` for an example run.
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|  */
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| 
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| /*  Copyright (C) 2018, ARM Limited, All Rights Reserved
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|  *  SPDX-License-Identifier: Apache-2.0
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|  *
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|  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
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|  *  not use this file except in compliance with the License.
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|  *  You may obtain a copy of the License at
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|  *
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|  *  http://www.apache.org/licenses/LICENSE-2.0
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|  *
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|  *  Unless required by applicable law or agreed to in writing, software
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|  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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|  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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|  *  See the License for the specific language governing permissions and
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|  *  limitations under the License.
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|  *
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|  *  This file is part of mbed TLS (https://tls.mbed.org)
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|  */
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| 
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| /* First include Mbed TLS headers to get the Mbed TLS configuration and
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|  * platform definitions that we'll use in this program. Also include
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|  * standard C headers for functions we'll use here. */
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| #if !defined(MBEDTLS_CONFIG_FILE)
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| #include "mbedtls/config.h"
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| #else
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| #include MBEDTLS_CONFIG_FILE
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| #endif
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| 
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| #include <stdlib.h>
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| #include <stdio.h>
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| #include <string.h>
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| 
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| #include "mbedtls/platform_util.h" // for mbedtls_platform_zeroize
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| 
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| /* If the build options we need are not enabled, compile a placeholder. */
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| #if !defined(MBEDTLS_SHA256_C) || !defined(MBEDTLS_MD_C) ||     \
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|     !defined(MBEDTLS_AES_C) || !defined(MBEDTLS_CCM_C) ||       \
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|     !defined(MBEDTLS_PSA_CRYPTO_C) || !defined(MBEDTLS_FS_IO)
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| int main( void )
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| {
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|     printf("MBEDTLS_SHA256_C and/or MBEDTLS_MD_C and/or "
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|            "MBEDTLS_AES_C and/or MBEDTLS_CCM_C and/or "
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|            "MBEDTLS_PSA_CRYPTO_C and/or MBEDTLS_FS_IO not defined.\n");
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|     return( 0 );
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| }
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| #else
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| 
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| /* The real program starts here. */
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| 
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| 
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| 
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| #include <psa/crypto.h>
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| 
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| /* Run a system function and bail out if it fails. */
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| #define SYS_CHECK( expr )                                       \
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|     do                                                          \
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|     {                                                           \
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|         if( ! ( expr ) )                                        \
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|         {                                                       \
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|             perror( #expr );                                    \
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|             status = DEMO_ERROR;                                \
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|             goto exit;                                          \
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|         }                                                       \
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|     }                                                           \
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|     while( 0 )
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| 
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| /* Run a PSA function and bail out if it fails. */
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| #define PSA_CHECK( expr )                                       \
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|     do                                                          \
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|     {                                                           \
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|         status = ( expr );                                      \
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|         if( status != PSA_SUCCESS )                             \
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|         {                                                       \
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|             printf( "Error %d at line %u: %s\n",                \
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|                     (int) status,                               \
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|                     __LINE__,                                   \
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|                     #expr );                                    \
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|             goto exit;                                          \
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|         }                                                       \
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|     }                                                           \
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|     while( 0 )
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| 
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| /* To report operational errors in this program, use an error code that is
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|  * different from every PSA error code. */
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| #define DEMO_ERROR 120
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| 
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| /* The maximum supported key ladder depth. */
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| #define MAX_LADDER_DEPTH 10
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| 
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| /* Salt to use when deriving an intermediate key. */
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| #define DERIVE_KEY_SALT ( (uint8_t *) "key_ladder_demo.derive" )
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| #define DERIVE_KEY_SALT_LENGTH ( strlen( (const char*) DERIVE_KEY_SALT ) )
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| 
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| /* Salt to use when deriving a wrapping key. */
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| #define WRAPPING_KEY_SALT ( (uint8_t *) "key_ladder_demo.wrap" )
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| #define WRAPPING_KEY_SALT_LENGTH ( strlen( (const char*) WRAPPING_KEY_SALT ) )
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| 
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| /* Size of the key derivation keys (applies both to the master key and
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|  * to intermediate keys). */
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| #define KEY_SIZE_BYTES 40
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| 
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| /* Algorithm for key derivation. */
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| #define KDF_ALG PSA_ALG_HKDF( PSA_ALG_SHA_256 )
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| 
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| /* Type and size of the key used to wrap data. */
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| #define WRAPPING_KEY_TYPE PSA_KEY_TYPE_AES
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| #define WRAPPING_KEY_BITS 128
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| 
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| /* Cipher mode used to wrap data. */
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| #define WRAPPING_ALG PSA_ALG_CCM
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| 
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| /* Nonce size used to wrap data. */
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| #define WRAPPING_IV_SIZE 13
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| 
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| /* Header used in files containing wrapped data. We'll save this header
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|  * directly without worrying about data representation issues such as
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|  * integer sizes and endianness, because the data is meant to be read
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|  * back by the same program on the same machine. */
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| #define WRAPPED_DATA_MAGIC "key_ladder_demo" // including trailing null byte
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| #define WRAPPED_DATA_MAGIC_LENGTH ( sizeof( WRAPPED_DATA_MAGIC ) )
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| typedef struct
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| {
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|     char magic[WRAPPED_DATA_MAGIC_LENGTH];
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|     size_t ad_size; /* Size of the additional data, which is this header. */
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|     size_t payload_size; /* Size of the encrypted data. */
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|     /* Store the IV inside the additional data. It's convenient. */
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|     uint8_t iv[WRAPPING_IV_SIZE];
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| } wrapped_data_header_t;
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| 
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| /* The modes that this program can operate in (see usage). */
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| enum program_mode
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| {
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|     MODE_GENERATE,
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|     MODE_SAVE,
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|     MODE_UNWRAP,
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|     MODE_WRAP
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| };
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| 
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| /* Save a key to a file. In the real world, you may want to export a derived
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|  * key sometimes, to share it with another party. */
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| static psa_status_t save_key( psa_key_handle_t key_handle,
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|                               const char *output_file_name )
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| {
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|     psa_status_t status = PSA_SUCCESS;
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|     uint8_t key_data[KEY_SIZE_BYTES];
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|     size_t key_size;
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|     FILE *key_file = NULL;
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| 
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|     PSA_CHECK( psa_export_key( key_handle,
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|                                key_data, sizeof( key_data ),
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|                                &key_size ) );
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|     SYS_CHECK( ( key_file = fopen( output_file_name, "wb" ) ) != NULL );
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|     SYS_CHECK( fwrite( key_data, 1, key_size, key_file ) == key_size );
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|     SYS_CHECK( fclose( key_file ) == 0 );
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|     key_file = NULL;
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| 
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| exit:
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|     if( key_file != NULL)
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|         fclose( key_file );
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|     return( status );
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| }
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| 
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| /* Generate a master key for use in this demo.
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|  *
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|  * Normally a master key would be non-exportable. For the purpose of this
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|  * demo, we want to save it to a file, to avoid relying on the keystore
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|  * capability of the PSA crypto library. */
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| static psa_status_t generate( const char *key_file_name )
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| {
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|     psa_status_t status = PSA_SUCCESS;
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|     psa_key_handle_t key_handle = 0;
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|     psa_key_policy_t policy = PSA_KEY_POLICY_INIT;
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| 
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|     PSA_CHECK( psa_allocate_key( &key_handle ) );
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|     psa_key_policy_set_usage( &policy,
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|                               PSA_KEY_USAGE_DERIVE | PSA_KEY_USAGE_EXPORT,
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|                               KDF_ALG );
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|     PSA_CHECK( psa_set_key_policy( key_handle, &policy ) );
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| 
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|     PSA_CHECK( psa_generate_key( key_handle,
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|                                  PSA_KEY_TYPE_DERIVE,
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|                                  PSA_BYTES_TO_BITS( KEY_SIZE_BYTES ),
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|                                  NULL, 0 ) );
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| 
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|     PSA_CHECK( save_key( key_handle, key_file_name ) );
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| 
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| exit:
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|     (void) psa_destroy_key( key_handle );
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|     return( status );
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| }
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| 
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| /* Load the master key from a file.
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|  *
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|  * In the real world, this master key would be stored in an internal memory
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|  * and the storage would be managed by the keystore capability of the PSA
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|  * crypto library. */
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| static psa_status_t import_key_from_file( psa_key_usage_t usage,
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|                                           psa_algorithm_t alg,
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|                                           const char *key_file_name,
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|                                           psa_key_handle_t *master_key_handle )
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| {
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|     psa_status_t status = PSA_SUCCESS;
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|     psa_key_policy_t policy = PSA_KEY_POLICY_INIT;
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|     uint8_t key_data[KEY_SIZE_BYTES];
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|     size_t key_size;
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|     FILE *key_file = NULL;
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|     unsigned char extra_byte;
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| 
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|     *master_key_handle = 0;
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| 
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|     SYS_CHECK( ( key_file = fopen( key_file_name, "rb" ) ) != NULL );
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|     SYS_CHECK( ( key_size = fread( key_data, 1, sizeof( key_data ),
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|                                    key_file ) ) != 0 );
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|     if( fread( &extra_byte, 1, 1, key_file ) != 0 )
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|     {
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|         printf( "Key file too large (max: %u).\n",
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|                 (unsigned) sizeof( key_data ) );
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|         status = DEMO_ERROR;
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|         goto exit;
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|     }
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|     SYS_CHECK( fclose( key_file ) == 0 );
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|     key_file = NULL;
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| 
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|     PSA_CHECK( psa_allocate_key( master_key_handle ) );
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|     psa_key_policy_set_usage( &policy, usage, alg );
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|     PSA_CHECK( psa_set_key_policy( *master_key_handle, &policy ) );
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|     PSA_CHECK( psa_import_key( *master_key_handle,
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|                                PSA_KEY_TYPE_DERIVE,
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|                                key_data, key_size ) );
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| exit:
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|     if( key_file != NULL )
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|         fclose( key_file );
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|     mbedtls_platform_zeroize( key_data, sizeof( key_data ) );
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|     if( status != PSA_SUCCESS )
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|     {
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|         /* If psa_allocate_key hasn't been called yet or has failed,
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|          * *master_key_handle is 0. psa_destroy_key(0) is guaranteed to do
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|          * nothing and return PSA_ERROR_INVALID_HANDLE. */
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|         (void) psa_destroy_key( *master_key_handle );
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|         *master_key_handle = 0;
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|     }
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|     return( status );
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| }
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| 
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| /* Derive the intermediate keys, using the list of labels provided on
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|  * the command line. On input, *key_handle is a handle to the master key.
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|  * This function closes the master key. On successful output, *key_handle
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|  * is a handle to the final derived key. */
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| static psa_status_t derive_key_ladder( const char *ladder[],
 | |
|                                        size_t ladder_depth,
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|                                        psa_key_handle_t *key_handle )
 | |
| {
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|     psa_status_t status = PSA_SUCCESS;
 | |
|     psa_key_policy_t policy = PSA_KEY_POLICY_INIT;
 | |
|     psa_crypto_generator_t generator = PSA_CRYPTO_GENERATOR_INIT;
 | |
|     size_t i;
 | |
|     psa_key_policy_set_usage( &policy,
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|                               PSA_KEY_USAGE_DERIVE | PSA_KEY_USAGE_EXPORT,
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|                               KDF_ALG );
 | |
| 
 | |
|     /* For each label in turn, ... */
 | |
|     for( i = 0; i < ladder_depth; i++ )
 | |
|     {
 | |
|         /* Start deriving material from the master key (if i=0) or from
 | |
|          * the current intermediate key (if i>0). */
 | |
|         PSA_CHECK( psa_key_derivation(
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|                        &generator,
 | |
|                        *key_handle,
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|                        KDF_ALG,
 | |
|                        DERIVE_KEY_SALT, DERIVE_KEY_SALT_LENGTH,
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|                        (uint8_t*) ladder[i], strlen( ladder[i] ),
 | |
|                        KEY_SIZE_BYTES ) );
 | |
|         /* When the parent key is not the master key, destroy it,
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|          * since it is no longer needed. */
 | |
|         PSA_CHECK( psa_close_key( *key_handle ) );
 | |
|         *key_handle = 0;
 | |
|         PSA_CHECK( psa_allocate_key( key_handle ) );
 | |
|         PSA_CHECK( psa_set_key_policy( *key_handle, &policy ) );
 | |
|         /* Use the generator obtained from the parent key to create
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|          * the next intermediate key. */
 | |
|         PSA_CHECK( psa_generator_import_key(
 | |
|                        *key_handle,
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|                        PSA_KEY_TYPE_DERIVE,
 | |
|                        PSA_BYTES_TO_BITS( KEY_SIZE_BYTES ),
 | |
|                        &generator ) );
 | |
|         PSA_CHECK( psa_generator_abort( &generator ) );
 | |
|     }
 | |
| 
 | |
| exit:
 | |
|     psa_generator_abort( &generator );
 | |
|     if( status != PSA_SUCCESS )
 | |
|     {
 | |
|         psa_close_key( *key_handle );
 | |
|         *key_handle = 0;
 | |
|     }
 | |
|     return( status );
 | |
| }
 | |
| 
 | |
| /* Derive a wrapping key from the last intermediate key. */
 | |
| static psa_status_t derive_wrapping_key( psa_key_usage_t usage,
 | |
|                                          psa_key_handle_t derived_key_handle,
 | |
|                                          psa_key_handle_t *wrapping_key_handle )
 | |
| {
 | |
|     psa_status_t status = PSA_SUCCESS;
 | |
|     psa_key_policy_t policy = PSA_KEY_POLICY_INIT;
 | |
|     psa_crypto_generator_t generator = PSA_CRYPTO_GENERATOR_INIT;
 | |
| 
 | |
|     *wrapping_key_handle = 0;
 | |
|     PSA_CHECK( psa_allocate_key( wrapping_key_handle ) );
 | |
|     psa_key_policy_set_usage( &policy, usage, WRAPPING_ALG );
 | |
|     PSA_CHECK( psa_set_key_policy( *wrapping_key_handle, &policy ) );
 | |
| 
 | |
|     PSA_CHECK( psa_key_derivation(
 | |
|                    &generator,
 | |
|                    derived_key_handle,
 | |
|                    KDF_ALG,
 | |
|                    WRAPPING_KEY_SALT, WRAPPING_KEY_SALT_LENGTH,
 | |
|                    NULL, 0,
 | |
|                    PSA_BITS_TO_BYTES( WRAPPING_KEY_BITS ) ) );
 | |
|     PSA_CHECK( psa_generator_import_key(
 | |
|                    *wrapping_key_handle,
 | |
|                    PSA_KEY_TYPE_AES,
 | |
|                    WRAPPING_KEY_BITS,
 | |
|                    &generator ) );
 | |
| 
 | |
| exit:
 | |
|     psa_generator_abort( &generator );
 | |
|     if( status != PSA_SUCCESS )
 | |
|     {
 | |
|         psa_close_key( *wrapping_key_handle );
 | |
|         *wrapping_key_handle = 0;
 | |
|     }
 | |
|     return( status );
 | |
| }
 | |
| 
 | |
| static psa_status_t wrap_data( const char *input_file_name,
 | |
|                                const char *output_file_name,
 | |
|                                psa_key_handle_t wrapping_key_handle )
 | |
| {
 | |
|     psa_status_t status;
 | |
|     FILE *input_file = NULL;
 | |
|     FILE *output_file = NULL;
 | |
|     long input_position;
 | |
|     size_t input_size;
 | |
|     size_t buffer_size = 0;
 | |
|     unsigned char *buffer = NULL;
 | |
|     size_t ciphertext_size;
 | |
|     wrapped_data_header_t header;
 | |
| 
 | |
|     /* Find the size of the data to wrap. */
 | |
|     SYS_CHECK( ( input_file = fopen( input_file_name, "rb" ) ) != NULL );
 | |
|     SYS_CHECK( fseek( input_file, 0, SEEK_END ) == 0 );
 | |
|     SYS_CHECK( ( input_position = ftell( input_file ) ) != -1 );
 | |
| #if LONG_MAX > SIZE_MAX
 | |
|     if( input_position > SIZE_MAX )
 | |
|     {
 | |
|         printf( "Input file too large.\n" );
 | |
|         status = DEMO_ERROR;
 | |
|         goto exit;
 | |
|     }
 | |
| #endif
 | |
|     input_size = input_position;
 | |
|     buffer_size = PSA_AEAD_ENCRYPT_OUTPUT_SIZE( WRAPPING_ALG, input_size );
 | |
|     /* Check for integer overflow. */
 | |
|     if( buffer_size < input_size )
 | |
|     {
 | |
|         printf( "Input file too large.\n" );
 | |
|         status = DEMO_ERROR;
 | |
|         goto exit;
 | |
|     }
 | |
| 
 | |
|     /* Load the data to wrap. */
 | |
|     SYS_CHECK( fseek( input_file, 0, SEEK_SET ) == 0 );
 | |
|     SYS_CHECK( ( buffer = calloc( 1, buffer_size ) ) != NULL );
 | |
|     SYS_CHECK( fread( buffer, 1, input_size, input_file ) == input_size );
 | |
|     SYS_CHECK( fclose( input_file ) == 0 );
 | |
|     input_file = NULL;
 | |
| 
 | |
|     /* Construct a header. */
 | |
|     memcpy( &header.magic, WRAPPED_DATA_MAGIC, WRAPPED_DATA_MAGIC_LENGTH );
 | |
|     header.ad_size = sizeof( header );
 | |
|     header.payload_size = input_size;
 | |
| 
 | |
|     /* Wrap the data. */
 | |
|     PSA_CHECK( psa_generate_random( header.iv, WRAPPING_IV_SIZE ) );
 | |
|     PSA_CHECK( psa_aead_encrypt( wrapping_key_handle, WRAPPING_ALG,
 | |
|                                  header.iv, WRAPPING_IV_SIZE,
 | |
|                                  (uint8_t *) &header, sizeof( header ),
 | |
|                                  buffer, input_size,
 | |
|                                  buffer, buffer_size,
 | |
|                                  &ciphertext_size ) );
 | |
| 
 | |
|     /* Write the output. */
 | |
|     SYS_CHECK( ( output_file = fopen( output_file_name, "wb" ) ) != NULL );
 | |
|     SYS_CHECK( fwrite( &header, 1, sizeof( header ),
 | |
|                        output_file ) == sizeof( header ) );
 | |
|     SYS_CHECK( fwrite( buffer, 1, ciphertext_size,
 | |
|                        output_file ) == ciphertext_size );
 | |
|     SYS_CHECK( fclose( output_file ) == 0 );
 | |
|     output_file = NULL;
 | |
| 
 | |
| exit:
 | |
|     if( input_file != NULL )
 | |
|         fclose( input_file );
 | |
|     if( output_file != NULL )
 | |
|         fclose( output_file );
 | |
|     if( buffer != NULL )
 | |
|         mbedtls_platform_zeroize( buffer, buffer_size );
 | |
|     free( buffer );
 | |
|     return( status );
 | |
| }
 | |
| 
 | |
| static psa_status_t unwrap_data( const char *input_file_name,
 | |
|                                  const char *output_file_name,
 | |
|                                  psa_key_handle_t wrapping_key_handle )
 | |
| {
 | |
|     psa_status_t status;
 | |
|     FILE *input_file = NULL;
 | |
|     FILE *output_file = NULL;
 | |
|     unsigned char *buffer = NULL;
 | |
|     size_t ciphertext_size = 0;
 | |
|     size_t plaintext_size;
 | |
|     wrapped_data_header_t header;
 | |
|     unsigned char extra_byte;
 | |
| 
 | |
|     /* Load and validate the header. */
 | |
|     SYS_CHECK( ( input_file = fopen( input_file_name, "rb" ) ) != NULL );
 | |
|     SYS_CHECK( fread( &header, 1, sizeof( header ),
 | |
|                       input_file ) == sizeof( header ) );
 | |
|     if( memcmp( &header.magic, WRAPPED_DATA_MAGIC,
 | |
|                 WRAPPED_DATA_MAGIC_LENGTH ) != 0 )
 | |
|     {
 | |
|         printf( "The input does not start with a valid magic header.\n" );
 | |
|         status = DEMO_ERROR;
 | |
|         goto exit;
 | |
|     }
 | |
|     if( header.ad_size != sizeof( header ) )
 | |
|     {
 | |
|         printf( "The header size is not correct.\n" );
 | |
|         status = DEMO_ERROR;
 | |
|         goto exit;
 | |
|     }
 | |
|     ciphertext_size =
 | |
|         PSA_AEAD_ENCRYPT_OUTPUT_SIZE( WRAPPING_ALG, header.payload_size );
 | |
|     /* Check for integer overflow. */
 | |
|     if( ciphertext_size < header.payload_size )
 | |
|     {
 | |
|         printf( "Input file too large.\n" );
 | |
|         status = DEMO_ERROR;
 | |
|         goto exit;
 | |
|     }
 | |
| 
 | |
|     /* Load the payload data. */
 | |
|     SYS_CHECK( ( buffer = calloc( 1, ciphertext_size ) ) != NULL );
 | |
|     SYS_CHECK( fread( buffer, 1, ciphertext_size,
 | |
|                       input_file ) == ciphertext_size );
 | |
|     if( fread( &extra_byte, 1, 1, input_file ) != 0 )
 | |
|     {
 | |
|         printf( "Extra garbage after ciphertext\n" );
 | |
|         status = DEMO_ERROR;
 | |
|         goto exit;
 | |
|     }
 | |
|     SYS_CHECK( fclose( input_file ) == 0 );
 | |
|     input_file = NULL;
 | |
| 
 | |
|     /* Unwrap the data. */
 | |
|     PSA_CHECK( psa_aead_decrypt( wrapping_key_handle, WRAPPING_ALG,
 | |
|                                  header.iv, WRAPPING_IV_SIZE,
 | |
|                                  (uint8_t *) &header, sizeof( header ),
 | |
|                                  buffer, ciphertext_size,
 | |
|                                  buffer, ciphertext_size,
 | |
|                                  &plaintext_size ) );
 | |
|     if( plaintext_size != header.payload_size )
 | |
|     {
 | |
|         printf( "Incorrect payload size in the header.\n" );
 | |
|         status = DEMO_ERROR;
 | |
|         goto exit;
 | |
|     }
 | |
| 
 | |
|     /* Write the output. */
 | |
|     SYS_CHECK( ( output_file = fopen( output_file_name, "wb" ) ) != NULL );
 | |
|     SYS_CHECK( fwrite( buffer, 1, plaintext_size,
 | |
|                        output_file ) == plaintext_size );
 | |
|     SYS_CHECK( fclose( output_file ) == 0 );
 | |
|     output_file = NULL;
 | |
| 
 | |
| exit:
 | |
|     if( input_file != NULL )
 | |
|         fclose( input_file );
 | |
|     if( output_file != NULL )
 | |
|         fclose( output_file );
 | |
|     if( buffer != NULL )
 | |
|         mbedtls_platform_zeroize( buffer, ciphertext_size );
 | |
|     free( buffer );
 | |
|     return( status );
 | |
| }
 | |
| 
 | |
| static psa_status_t run( enum program_mode mode,
 | |
|                          const char *key_file_name,
 | |
|                          const char *ladder[], size_t ladder_depth,
 | |
|                          const char *input_file_name,
 | |
|                          const char *output_file_name )
 | |
| {
 | |
|     psa_status_t status = PSA_SUCCESS;
 | |
|     psa_key_handle_t derivation_key_handle = 0;
 | |
|     psa_key_handle_t wrapping_key_handle = 0;
 | |
| 
 | |
|     /* Initialize the PSA crypto library. */
 | |
|     PSA_CHECK( psa_crypto_init( ) );
 | |
| 
 | |
|     /* Generate mode is unlike the others. Generate the master key and exit. */
 | |
|     if( mode == MODE_GENERATE )
 | |
|         return( generate( key_file_name ) );
 | |
| 
 | |
|     /* Read the master key. */
 | |
|     PSA_CHECK( import_key_from_file( PSA_KEY_USAGE_DERIVE | PSA_KEY_USAGE_EXPORT,
 | |
|                                      KDF_ALG,
 | |
|                                      key_file_name,
 | |
|                                      &derivation_key_handle ) );
 | |
| 
 | |
|     /* Calculate the derived key for this session. */
 | |
|     PSA_CHECK( derive_key_ladder( ladder, ladder_depth,
 | |
|                                   &derivation_key_handle ) );
 | |
| 
 | |
|     switch( mode )
 | |
|     {
 | |
|         case MODE_SAVE:
 | |
|             PSA_CHECK( save_key( derivation_key_handle, output_file_name ) );
 | |
|             break;
 | |
|         case MODE_UNWRAP:
 | |
|             PSA_CHECK( derive_wrapping_key( PSA_KEY_USAGE_DECRYPT,
 | |
|                                             derivation_key_handle,
 | |
|                                             &wrapping_key_handle ) );
 | |
|             PSA_CHECK( unwrap_data( input_file_name, output_file_name,
 | |
|                                     wrapping_key_handle ) );
 | |
|             break;
 | |
|         case MODE_WRAP:
 | |
|             PSA_CHECK( derive_wrapping_key( PSA_KEY_USAGE_ENCRYPT,
 | |
|                                             derivation_key_handle,
 | |
|                                             &wrapping_key_handle ) );
 | |
|             PSA_CHECK( wrap_data( input_file_name, output_file_name,
 | |
|                                   wrapping_key_handle ) );
 | |
|             break;
 | |
|         default:
 | |
|             /* Unreachable but some compilers don't realize it. */
 | |
|             break;
 | |
|     }
 | |
| 
 | |
| exit:
 | |
|     /* Close any remaining key. Deinitializing the crypto library would do
 | |
|      * this anyway, but explicitly closing handles makes the code easier
 | |
|      * to reuse. */
 | |
|     (void) psa_close_key( derivation_key_handle );
 | |
|     (void) psa_close_key( wrapping_key_handle );
 | |
|     /* Deinitialize the PSA crypto library. */
 | |
|     mbedtls_psa_crypto_free( );
 | |
|     return( status );
 | |
| }
 | |
| 
 | |
| static void usage( void )
 | |
| {
 | |
|     printf( "Usage: key_ladder_demo MODE [OPTION=VALUE]...\n" );
 | |
|     printf( "Demonstrate the usage of a key derivation ladder.\n" );
 | |
|     printf( "\n" );
 | |
|     printf( "Modes:\n" );
 | |
|     printf( "  generate  Generate the master key\n" );
 | |
|     printf( "  save      Save the derived key\n" );
 | |
|     printf( "  unwrap    Unwrap (decrypt) input with the derived key\n" );
 | |
|     printf( "  wrap      Wrap (encrypt) input with the derived key\n" );
 | |
|     printf( "\n" );
 | |
|     printf( "Options:\n" );
 | |
|     printf( "  input=FILENAME    Input file (required for wrap/unwrap)\n" );
 | |
|     printf( "  master=FILENAME   File containing the master key (default: master.key)\n" );
 | |
|     printf( "  output=FILENAME   Output file (required for save/wrap/unwrap)\n" );
 | |
|     printf( "  label=TEXT        Label for the key derivation.\n" );
 | |
|     printf( "                    This may be repeated multiple times.\n" );
 | |
|     printf( "                    To get the same key, you must use the same master key\n" );
 | |
|     printf( "                    and the same sequence of labels.\n" );
 | |
| }
 | |
| 
 | |
| #if defined(MBEDTLS_CHECK_PARAMS)
 | |
| #include "mbedtls/platform_util.h"
 | |
| void mbedtls_param_failed( const char *failure_condition,
 | |
|                            const char *file,
 | |
|                            int line )
 | |
| {
 | |
|     printf( "%s:%i: Input param failed - %s\n",
 | |
|                     file, line, failure_condition );
 | |
|     exit( EXIT_FAILURE );
 | |
| }
 | |
| #endif
 | |
| 
 | |
| int main( int argc, char *argv[] )
 | |
| {
 | |
|     const char *key_file_name = "master.key";
 | |
|     const char *input_file_name = NULL;
 | |
|     const char *output_file_name = NULL;
 | |
|     const char *ladder[MAX_LADDER_DEPTH];
 | |
|     size_t ladder_depth = 0;
 | |
|     int i;
 | |
|     enum program_mode mode;
 | |
|     psa_status_t status;
 | |
| 
 | |
|     if( argc <= 1 ||
 | |
|         strcmp( argv[1], "help" ) == 0 ||
 | |
|         strcmp( argv[1], "-help" ) == 0 ||
 | |
|         strcmp( argv[1], "--help" ) == 0 )
 | |
|     {
 | |
|         usage( );
 | |
|         return( EXIT_SUCCESS );
 | |
|     }
 | |
| 
 | |
|     for( i = 2; i < argc; i++ )
 | |
|     {
 | |
|         char *q = strchr( argv[i], '=' );
 | |
|         if( q == NULL )
 | |
|         {
 | |
|             printf( "Missing argument to option %s\n", argv[i] );
 | |
|             goto usage_failure;
 | |
|         }
 | |
|         *q = 0;
 | |
|         ++q;
 | |
|         if( strcmp( argv[i], "input" ) == 0 )
 | |
|             input_file_name = q;
 | |
|         else if( strcmp( argv[i], "label" ) == 0 )
 | |
|         {
 | |
|             if( ladder_depth == MAX_LADDER_DEPTH )
 | |
|             {
 | |
|                 printf( "Maximum ladder depth %u exceeded.\n",
 | |
|                                 (unsigned) MAX_LADDER_DEPTH );
 | |
|                 return( EXIT_FAILURE );
 | |
|             }
 | |
|             ladder[ladder_depth] = q;
 | |
|             ++ladder_depth;
 | |
|         }
 | |
|         else if( strcmp( argv[i], "master" ) == 0 )
 | |
|             key_file_name = q;
 | |
|         else if( strcmp( argv[i], "output" ) == 0 )
 | |
|             output_file_name = q;
 | |
|         else
 | |
|         {
 | |
|             printf( "Unknown option: %s\n", argv[i] );
 | |
|             goto usage_failure;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     if( strcmp( argv[1], "generate" ) == 0 )
 | |
|         mode = MODE_GENERATE;
 | |
|     else if( strcmp( argv[1], "save" ) == 0 )
 | |
|         mode = MODE_SAVE;
 | |
|     else if( strcmp( argv[1], "unwrap" ) == 0 )
 | |
|         mode = MODE_UNWRAP;
 | |
|     else if( strcmp( argv[1], "wrap" ) == 0 )
 | |
|         mode = MODE_WRAP;
 | |
|     else
 | |
|     {
 | |
|         printf( "Unknown action: %s\n", argv[1] );
 | |
|         goto usage_failure;
 | |
|     }
 | |
| 
 | |
|     if( input_file_name == NULL &&
 | |
|         ( mode == MODE_WRAP || mode == MODE_UNWRAP ) )
 | |
|     {
 | |
|         printf( "Required argument missing: input\n" );
 | |
|         return( DEMO_ERROR );
 | |
|     }
 | |
|     if( output_file_name == NULL &&
 | |
|         ( mode == MODE_SAVE || mode == MODE_WRAP || mode == MODE_UNWRAP ) )
 | |
|     {
 | |
|         printf( "Required argument missing: output\n" );
 | |
|         return( DEMO_ERROR );
 | |
|     }
 | |
| 
 | |
|     status = run( mode, key_file_name,
 | |
|                   ladder, ladder_depth,
 | |
|                   input_file_name, output_file_name );
 | |
|     return( status == PSA_SUCCESS ?
 | |
|             EXIT_SUCCESS :
 | |
|             EXIT_FAILURE );
 | |
| 
 | |
| usage_failure:
 | |
|     usage( );
 | |
|     return( EXIT_FAILURE );
 | |
| }
 | |
| #endif /* MBEDTLS_SHA256_C && MBEDTLS_MD_C && MBEDTLS_AES_C && MBEDTLS_CCM_C && MBEDTLS_PSA_CRYPTO_C && MBEDTLS_FS_IO */
 |