mbedtls/programs/pkey/rsa_verify.c
2018-06-14 23:01:55 +01:00

166 lines
4.4 KiB
C

/*
* RSA/SHA-256 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_printf printf
#define mbedtls_snprintf snprintf
#define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
#define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
#endif /* MBEDTLS_PLATFORM_C */
#if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_RSA_C) || \
!defined(MBEDTLS_SHA256_C) || !defined(MBEDTLS_MD_C) || \
!defined(MBEDTLS_FS_IO)
int main( void )
{
mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_RSA_C and/or "
"MBEDTLS_MD_C and/or "
"MBEDTLS_SHA256_C and/or MBEDTLS_FS_IO not defined.\n");
return( 0 );
}
#else
#include "mbedtls/rsa.h"
#include "mbedtls/md.h"
#include <stdio.h>
#include <string.h>
int main( int argc, char *argv[] )
{
FILE *f;
int ret = 1, c;
int exit_code = MBEDTLS_EXIT_FAILURE;
size_t i;
mbedtls_rsa_context rsa;
unsigned char hash[32];
unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
char filename[512];
mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 );
if( argc != 2 )
{
mbedtls_printf( "usage: rsa_verify <filename>\n" );
#if defined(_WIN32)
mbedtls_printf( "\n" );
#endif
goto exit;
}
mbedtls_printf( "\n . Reading public key from rsa_pub.txt" );
fflush( stdout );
if( ( f = fopen( "rsa_pub.txt", "rb" ) ) == NULL )
{
mbedtls_printf( " failed\n ! Could not open rsa_pub.txt\n" \
" ! Please run rsa_genkey first\n\n" );
goto exit;
}
if( ( ret = mbedtls_mpi_read_file( &rsa.N, 16, f ) ) != 0 ||
( ret = mbedtls_mpi_read_file( &rsa.E, 16, f ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_mpi_read_file returned %d\n\n", ret );
fclose( f );
goto exit;
}
rsa.len = ( mbedtls_mpi_bitlen( &rsa.N ) + 7 ) >> 3;
fclose( f );
/*
* Extract the RSA signature from the text file
*/
mbedtls_snprintf( filename, sizeof(filename), "%s.sig", argv[1] );
if( ( f = fopen( filename, "rb" ) ) == NULL )
{
mbedtls_printf( "\n ! Could not open %s\n\n", filename );
goto exit;
}
i = 0;
while( fscanf( f, "%02X", &c ) > 0 &&
i < (int) sizeof( buf ) )
buf[i++] = (unsigned char) c;
fclose( f );
if( i != rsa.len )
{
mbedtls_printf( "\n ! Invalid RSA signature format\n\n" );
goto exit;
}
/*
* Compute the SHA-256 hash of the input file and
* verify the signature
*/
mbedtls_printf( "\n . Verifying the RSA/SHA-256 signature" );
fflush( stdout );
if( ( ret = mbedtls_md_file(
mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ),
argv[1], hash ) ) != 0 )
{
mbedtls_printf( " failed\n ! Could not open or read %s\n\n", argv[1] );
goto exit;
}
if( ( ret = mbedtls_rsa_pkcs1_verify( &rsa, NULL, NULL, MBEDTLS_RSA_PUBLIC,
MBEDTLS_MD_SHA256, 20, hash, buf ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_rsa_pkcs1_verify returned -0x%0x\n\n", -ret );
goto exit;
}
mbedtls_printf( "\n . OK (the signature is valid)\n\n" );
exit_code = MBEDTLS_EXIT_SUCCESS;
exit:
mbedtls_rsa_free( &rsa );
#if defined(_WIN32)
mbedtls_printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
return( exit_code );
}
#endif /* MBEDTLS_BIGNUM_C && MBEDTLS_RSA_C && MBEDTLS_SHA256_C &&
MBEDTLS_FS_IO */