mbedtls/programs/pkey/gen_key.c
Krzysztof Stachowiak a08652233d Unify the example programs' termination
This is done to account for platforms, for which we want custom behavior
upon the program termination, hence we call `mbedtls_exit()` instead of
returning from `main()`.

For the sake of consistency, introduces the modifications have been made
to the test and utility examples as well. These, while less likely to be
used in the low level environments, won't suffer from such a change.
2020-05-11 22:20:32 +02:00

451 lines
13 KiB
C

/*
* Key generation application
*
* 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_exit exit
#define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
#define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
#endif /* MBEDTLS_PLATFORM_C */
#if defined(MBEDTLS_PK_WRITE_C) && defined(MBEDTLS_FS_IO) && \
defined(MBEDTLS_ENTROPY_C) && defined(MBEDTLS_CTR_DRBG_C)
#include "mbedtls/error.h"
#include "mbedtls/pk.h"
#include "mbedtls/ecdsa.h"
#include "mbedtls/rsa.h"
#include "mbedtls/error.h"
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if !defined(_WIN32)
#include <unistd.h>
#define DEV_RANDOM_THRESHOLD 32
int dev_random_entropy_poll( void *data, unsigned char *output,
size_t len, size_t *olen )
{
FILE *file;
size_t ret, left = len;
unsigned char *p = output;
((void) data);
*olen = 0;
file = fopen( "/dev/random", "rb" );
if( file == NULL )
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
while( left > 0 )
{
/* /dev/random can return much less than requested. If so, try again */
ret = fread( p, 1, left, file );
if( ret == 0 && ferror( file ) )
{
fclose( file );
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
}
p += ret;
left -= ret;
sleep( 1 );
}
fclose( file );
*olen = len;
return( 0 );
}
#endif /* !_WIN32 */
#endif
#if defined(MBEDTLS_ECP_C)
#define DFL_EC_CURVE mbedtls_ecp_curve_list()->grp_id
#else
#define DFL_EC_CURVE 0
#endif
#if !defined(_WIN32) && defined(MBEDTLS_FS_IO)
#define USAGE_DEV_RANDOM \
" use_dev_random=0|1 default: 0\n"
#else
#define USAGE_DEV_RANDOM ""
#endif /* !_WIN32 && MBEDTLS_FS_IO */
#define FORMAT_PEM 0
#define FORMAT_DER 1
#define DFL_TYPE MBEDTLS_PK_RSA
#define DFL_RSA_KEYSIZE 4096
#define DFL_FILENAME "keyfile.key"
#define DFL_FORMAT FORMAT_PEM
#define DFL_USE_DEV_RANDOM 0
#define USAGE \
"\n usage: gen_key param=<>...\n" \
"\n acceptable parameters:\n" \
" type=rsa|ec default: rsa\n" \
" rsa_keysize=%%d default: 4096\n" \
" ec_curve=%%s see below\n" \
" filename=%%s default: keyfile.key\n" \
" format=pem|der default: pem\n" \
USAGE_DEV_RANDOM \
"\n"
#if !defined(MBEDTLS_PK_WRITE_C) || !defined(MBEDTLS_PEM_WRITE_C) || \
!defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_ENTROPY_C) || \
!defined(MBEDTLS_CTR_DRBG_C)
int main( void )
{
mbedtls_printf( "MBEDTLS_PK_WRITE_C and/or MBEDTLS_FS_IO and/or "
"MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C and/or "
"MBEDTLS_PEM_WRITE_C"
"not defined.\n" );
mbedtls_exit( 0 );
}
#else
/*
* global options
*/
struct options
{
int type; /* the type of key to generate */
int rsa_keysize; /* length of key in bits */
int ec_curve; /* curve identifier for EC keys */
const char *filename; /* filename of the key file */
int format; /* the output format to use */
int use_dev_random; /* use /dev/random as entropy source */
} opt;
static int write_private_key( mbedtls_pk_context *key, const char *output_file )
{
int ret;
FILE *f;
unsigned char output_buf[16000];
unsigned char *c = output_buf;
size_t len = 0;
memset(output_buf, 0, 16000);
if( opt.format == FORMAT_PEM )
{
if( ( ret = mbedtls_pk_write_key_pem( key, output_buf, 16000 ) ) != 0 )
return( ret );
len = strlen( (char *) output_buf );
}
else
{
if( ( ret = mbedtls_pk_write_key_der( key, output_buf, 16000 ) ) < 0 )
return( ret );
len = ret;
c = output_buf + sizeof(output_buf) - len;
}
if( ( f = fopen( output_file, "wb" ) ) == NULL )
return( -1 );
if( fwrite( c, 1, len, f ) != len )
{
fclose( f );
return( -1 );
}
fclose( f );
return( 0 );
}
int main( int argc, char *argv[] )
{
int ret = 1;
int exit_code = MBEDTLS_EXIT_FAILURE;
mbedtls_pk_context key;
char buf[1024];
int i;
char *p, *q;
mbedtls_mpi N, P, Q, D, E, DP, DQ, QP;
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
const char *pers = "gen_key";
#if defined(MBEDTLS_ECP_C)
const mbedtls_ecp_curve_info *curve_info;
#endif
/*
* Set to sane values
*/
mbedtls_mpi_init( &N ); mbedtls_mpi_init( &P ); mbedtls_mpi_init( &Q );
mbedtls_mpi_init( &D ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &DP );
mbedtls_mpi_init( &DQ ); mbedtls_mpi_init( &QP );
mbedtls_pk_init( &key );
mbedtls_ctr_drbg_init( &ctr_drbg );
memset( buf, 0, sizeof( buf ) );
if( argc == 0 )
{
usage:
mbedtls_printf( USAGE );
#if defined(MBEDTLS_ECP_C)
mbedtls_printf( " available ec_curve values:\n" );
curve_info = mbedtls_ecp_curve_list();
mbedtls_printf( " %s (default)\n", curve_info->name );
while( ( ++curve_info )->name != NULL )
mbedtls_printf( " %s\n", curve_info->name );
#endif /* MBEDTLS_ECP_C */
goto exit;
}
opt.type = DFL_TYPE;
opt.rsa_keysize = DFL_RSA_KEYSIZE;
opt.ec_curve = DFL_EC_CURVE;
opt.filename = DFL_FILENAME;
opt.format = DFL_FORMAT;
opt.use_dev_random = DFL_USE_DEV_RANDOM;
for( i = 1; i < argc; i++ )
{
p = argv[i];
if( ( q = strchr( p, '=' ) ) == NULL )
goto usage;
*q++ = '\0';
if( strcmp( p, "type" ) == 0 )
{
if( strcmp( q, "rsa" ) == 0 )
opt.type = MBEDTLS_PK_RSA;
else if( strcmp( q, "ec" ) == 0 )
opt.type = MBEDTLS_PK_ECKEY;
else
goto usage;
}
else if( strcmp( p, "format" ) == 0 )
{
if( strcmp( q, "pem" ) == 0 )
opt.format = FORMAT_PEM;
else if( strcmp( q, "der" ) == 0 )
opt.format = FORMAT_DER;
else
goto usage;
}
else if( strcmp( p, "rsa_keysize" ) == 0 )
{
opt.rsa_keysize = atoi( q );
if( opt.rsa_keysize < 1024 ||
opt.rsa_keysize > MBEDTLS_MPI_MAX_BITS )
goto usage;
}
#if defined(MBEDTLS_ECP_C)
else if( strcmp( p, "ec_curve" ) == 0 )
{
if( ( curve_info = mbedtls_ecp_curve_info_from_name( q ) ) == NULL )
goto usage;
opt.ec_curve = curve_info->grp_id;
}
#endif
else if( strcmp( p, "filename" ) == 0 )
opt.filename = q;
else if( strcmp( p, "use_dev_random" ) == 0 )
{
opt.use_dev_random = atoi( q );
if( opt.use_dev_random < 0 || opt.use_dev_random > 1 )
goto usage;
}
else
goto usage;
}
mbedtls_printf( "\n . Seeding the random number generator..." );
fflush( stdout );
mbedtls_entropy_init( &entropy );
#if !defined(_WIN32) && defined(MBEDTLS_FS_IO)
if( opt.use_dev_random )
{
if( ( ret = mbedtls_entropy_add_source( &entropy, dev_random_entropy_poll,
NULL, DEV_RANDOM_THRESHOLD,
MBEDTLS_ENTROPY_SOURCE_STRONG ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_entropy_add_source returned -0x%04x\n", -ret );
goto exit;
}
mbedtls_printf("\n Using /dev/random, so can take a long time! " );
fflush( stdout );
}
#endif /* !_WIN32 && MBEDTLS_FS_IO */
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 -0x%04x\n", -ret );
goto exit;
}
/*
* 1.1. Generate the key
*/
mbedtls_printf( "\n . Generating the private key ..." );
fflush( stdout );
if( ( ret = mbedtls_pk_setup( &key,
mbedtls_pk_info_from_type( (mbedtls_pk_type_t) opt.type ) ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_pk_setup returned -0x%04x", -ret );
goto exit;
}
#if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_GENPRIME)
if( opt.type == MBEDTLS_PK_RSA )
{
ret = mbedtls_rsa_gen_key( mbedtls_pk_rsa( key ), mbedtls_ctr_drbg_random, &ctr_drbg,
opt.rsa_keysize, 65537 );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_rsa_gen_key returned -0x%04x", -ret );
goto exit;
}
}
else
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECP_C)
if( opt.type == MBEDTLS_PK_ECKEY )
{
ret = mbedtls_ecp_gen_key( (mbedtls_ecp_group_id) opt.ec_curve,
mbedtls_pk_ec( key ),
mbedtls_ctr_drbg_random, &ctr_drbg );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecp_gen_key returned -0x%04x", -ret );
goto exit;
}
}
else
#endif /* MBEDTLS_ECP_C */
{
mbedtls_printf( " failed\n ! key type not supported\n" );
goto exit;
}
/*
* 1.2 Print the key
*/
mbedtls_printf( " ok\n . Key information:\n" );
#if defined(MBEDTLS_RSA_C)
if( mbedtls_pk_get_type( &key ) == MBEDTLS_PK_RSA )
{
mbedtls_rsa_context *rsa = mbedtls_pk_rsa( key );
if( ( ret = mbedtls_rsa_export ( rsa, &N, &P, &Q, &D, &E ) ) != 0 ||
( ret = mbedtls_rsa_export_crt( rsa, &DP, &DQ, &QP ) ) != 0 )
{
mbedtls_printf( " failed\n ! could not export RSA parameters\n\n" );
goto exit;
}
mbedtls_mpi_write_file( "N: ", &N, 16, NULL );
mbedtls_mpi_write_file( "E: ", &E, 16, NULL );
mbedtls_mpi_write_file( "D: ", &D, 16, NULL );
mbedtls_mpi_write_file( "P: ", &P, 16, NULL );
mbedtls_mpi_write_file( "Q: ", &Q, 16, NULL );
mbedtls_mpi_write_file( "DP: ", &DP, 16, NULL );
mbedtls_mpi_write_file( "DQ: ", &DQ, 16, NULL );
mbedtls_mpi_write_file( "QP: ", &QP, 16, NULL );
}
else
#endif
#if defined(MBEDTLS_ECP_C)
if( mbedtls_pk_get_type( &key ) == MBEDTLS_PK_ECKEY )
{
mbedtls_ecp_keypair *ecp = mbedtls_pk_ec( key );
mbedtls_printf( "curve: %s\n",
mbedtls_ecp_curve_info_from_grp_id( ecp->grp.id )->name );
mbedtls_mpi_write_file( "X_Q: ", &ecp->Q.X, 16, NULL );
mbedtls_mpi_write_file( "Y_Q: ", &ecp->Q.Y, 16, NULL );
mbedtls_mpi_write_file( "D: ", &ecp->d , 16, NULL );
}
else
#endif
mbedtls_printf(" ! key type not supported\n");
/*
* 1.3 Export key
*/
mbedtls_printf( " . Writing key to file..." );
if( ( ret = write_private_key( &key, opt.filename ) ) != 0 )
{
mbedtls_printf( " failed\n" );
goto exit;
}
mbedtls_printf( " ok\n" );
exit_code = MBEDTLS_EXIT_SUCCESS;
exit:
if( exit_code != MBEDTLS_EXIT_SUCCESS )
{
#ifdef MBEDTLS_ERROR_C
mbedtls_strerror( ret, buf, sizeof( buf ) );
mbedtls_printf( " - %s\n", buf );
#else
mbedtls_printf("\n");
#endif
}
mbedtls_mpi_free( &N ); mbedtls_mpi_free( &P ); mbedtls_mpi_free( &Q );
mbedtls_mpi_free( &D ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &DP );
mbedtls_mpi_free( &DQ ); mbedtls_mpi_free( &QP );
mbedtls_pk_free( &key );
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
#if defined(_WIN32)
mbedtls_printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
mbedtls_exit( exit_code );
}
#endif /* MBEDTLS_PK_WRITE_C && MBEDTLS_PEM_WRITE_C && MBEDTLS_FS_IO &&
* MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */