text: /***************************************************************************//**
   * # License
   *
   * The licensor of this software is Silicon Laboratories Inc. Your use of this
   * software is governed by the terms of Silicon Labs Master Software License
   * Agreement (MSLA) available at
   * www.silabs.com/about-us/legal/master-software-license-agreement. This
   * software is Third Party Software licensed by Silicon Labs from a third party
   * and is governed by the sections of the MSLA applicable to Third Party
   * Software and the additional terms set forth below.
   *
   ******************************************************************************/
  /*
   *  Public key-based signature verification program
   *
   *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
   *  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.
   *
   *  This file is part of mbed TLS (https://tls.mbed.org)
   */
  
  #if !defined(MBEDTLS_CONFIG_FILE)
  #include "mbedtls/config.h"
  #else
  #include MBEDTLS_CONFIG_FILE
  #endif
  
  #if defined(MBEDTLS_PLATFORM_C)
  #include "mbedtls/platform.h"
  #else
  #include <stdio.h>
  #include <stdlib.h>
  #define mbedtls_snprintf        snprintf
  #define mbedtls_printf          printf
  #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
  #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
  #endif /* MBEDTLS_PLATFORM_C */
  
  #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_MD_C) || \
      !defined(MBEDTLS_SHA256_C) || !defined(MBEDTLS_PK_PARSE_C) ||   \
      !defined(MBEDTLS_FS_IO)
  int main( void )
  {
      mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_MD_C and/or "
             "MBEDTLS_SHA256_C and/or MBEDTLS_PK_PARSE_C and/or "
             "MBEDTLS_FS_IO not defined.\n");
      return( 0 );
  }
  #else
  
  #include "mbedtls/error.h"
  #include "mbedtls/md.h"
  #include "mbedtls/pk.h"
  
  #include <stdio.h>
  #include <string.h>
  
  int main( int argc, char *argv[] )
  {
      FILE *f;
      int ret = 1;
      int exit_code = MBEDTLS_EXIT_FAILURE;
      size_t i;
      mbedtls_pk_context pk;
      unsigned char hash[32];
      unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
      char filename[512];
  
      mbedtls_pk_init( &pk );
  
      if( argc != 3 )
      {
          mbedtls_printf( "usage: mbedtls_pk_verify <key_file> <filename>\n" );
  
  #if defined(_WIN32)
          mbedtls_printf( "\n" );
  #endif
  
          goto exit;
      }
  
      mbedtls_printf( "\n  . Reading public key from '%s'", argv[1] );
      fflush( stdout );
  
      if( ( ret = mbedtls_pk_parse_public_keyfile( &pk, argv[1] ) ) != 0 )
      {
          mbedtls_printf( " failed\n  ! mbedtls_pk_parse_public_keyfile returned -0x%04x\n", -ret );
          goto exit;
      }
  
      /*
       * Extract the signature from the file
       */
      mbedtls_snprintf( filename, sizeof(filename), "%s.sig", argv[2] );
  
      if( ( f = fopen( filename, "rb" ) ) == NULL )
      {
          mbedtls_printf( "\n  ! Could not open %s\n\n", filename );
          goto exit;
      }
  
  
      i = fread( buf, 1, sizeof(buf), f );
  
      fclose( f );
  
      /*
       * Compute the SHA-256 hash of the input file and
       * verify the signature
       */
      mbedtls_printf( "\n  . Verifying the SHA-256 signature" );
      fflush( stdout );
  
      if( ( ret = mbedtls_md_file(
                      mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ),
                      argv[2], hash ) ) != 0 )
      {
          mbedtls_printf( " failed\n  ! Could not open or read %s\n\n", argv[2] );
          goto exit;
      }
  
      if( ( ret = mbedtls_pk_verify( &pk, MBEDTLS_MD_SHA256, hash, 0,
                             buf, i ) ) != 0 )
      {
          mbedtls_printf( " failed\n  ! mbedtls_pk_verify returned -0x%04x\n", -ret );
          goto exit;
      }
  
      mbedtls_printf( "\n  . OK (the signature is valid)\n\n" );
  
      exit_code = MBEDTLS_EXIT_SUCCESS;
  
  exit:
      mbedtls_pk_free( &pk );
  
  #if defined(MBEDTLS_ERROR_C)
      if( exit_code != MBEDTLS_EXIT_SUCCESS )
      {
          mbedtls_strerror( ret, (char *) buf, sizeof(buf) );
          mbedtls_printf( "  !  Last error was: %s\n", buf );
      }
  #endif
  
  #if defined(_WIN32)
      mbedtls_printf( "  + Press Enter to exit this program.\n" );
      fflush( stdout ); getchar();
  #endif
  
      return( exit_code );
  }
  #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_SHA256_C &&
            MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO */
  