mbedtls/programs/pkey/pk_decrypt.c
2015-09-04 14:21:07 +02:00

169 lines
4.5 KiB
C

/*
* Public key-based simple decryption 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>
#define mbedtls_printf printf
#endif
#if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_PK_PARSE_C) && \
defined(MBEDTLS_FS_IO) && defined(MBEDTLS_ENTROPY_C) && \
defined(MBEDTLS_CTR_DRBG_C)
#include "mbedtls/error.h"
#include "mbedtls/pk.h"
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include <stdio.h>
#include <string.h>
#endif
#if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_PK_PARSE_C) || \
!defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_ENTROPY_C) || \
!defined(MBEDTLS_CTR_DRBG_C)
int main( void )
{
mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_PK_PARSE_C and/or "
"MBEDTLS_FS_IO and/or MBEDTLS_ENTROPY_C and/or "
"MBEDTLS_CTR_DRBG_C not defined.\n");
return( 0 );
}
#else
int main( int argc, char *argv[] )
{
FILE *f;
int ret, c;
size_t i, olen = 0;
mbedtls_pk_context pk;
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
unsigned char result[1024];
unsigned char buf[512];
const char *pers = "mbedtls_pk_decrypt";
((void) argv);
mbedtls_ctr_drbg_init( &ctr_drbg );
memset(result, 0, sizeof( result ) );
ret = 1;
if( argc != 2 )
{
mbedtls_printf( "usage: mbedtls_pk_decrypt <key_file>\n" );
#if defined(_WIN32)
mbedtls_printf( "\n" );
#endif
goto exit;
}
mbedtls_printf( "\n . Seeding the random number generator..." );
fflush( stdout );
mbedtls_entropy_init( &entropy );
if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
(const unsigned char *) pers,
strlen( pers ) ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned %d\n", ret );
goto exit;
}
mbedtls_printf( "\n . Reading private key from '%s'", argv[1] );
fflush( stdout );
mbedtls_pk_init( &pk );
if( ( ret = mbedtls_pk_parse_keyfile( &pk, argv[1], "" ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_pk_parse_keyfile returned -0x%04x\n", -ret );
goto exit;
}
/*
* Extract the RSA encrypted value from the text file
*/
ret = 1;
if( ( f = fopen( "result-enc.txt", "rb" ) ) == NULL )
{
mbedtls_printf( "\n ! Could not open %s\n\n", "result-enc.txt" );
goto exit;
}
i = 0;
while( fscanf( f, "%02X", &c ) > 0 &&
i < (int) sizeof( buf ) )
buf[i++] = (unsigned char) c;
fclose( f );
/*
* Decrypt the encrypted RSA data and print the result.
*/
mbedtls_printf( "\n . Decrypting the encrypted data" );
fflush( stdout );
if( ( ret = mbedtls_pk_decrypt( &pk, buf, i, result, &olen, sizeof(result),
mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_pk_decrypt returned -0x%04x\n", -ret );
goto exit;
}
mbedtls_printf( "\n . OK\n\n" );
mbedtls_printf( "The decrypted result is: '%s'\n\n", result );
ret = 0;
exit:
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
#if defined(MBEDTLS_ERROR_C)
if( ret != 0 )
{
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( ret );
}
#endif /* MBEDTLS_BIGNUM_C && MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO &&
MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */