mirror of
https://github.com/cuberite/polarssl.git
synced 2025-11-03 20:22:59 -05:00
526 lines
15 KiB
C
526 lines
15 KiB
C
/*
|
|
* CTR_DRBG implementation based on AES-256 (NIST SP 800-90)
|
|
*
|
|
* Copyright (C) 2006-2014, Brainspark B.V.
|
|
*
|
|
* This file is part of PolarSSL (http://www.polarssl.org)
|
|
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
|
|
*
|
|
* All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
/*
|
|
* The NIST SP 800-90 DRBGs are described in the following publucation.
|
|
*
|
|
* http://csrc.nist.gov/publications/nistpubs/800-90/SP800-90revised_March2007.pdf
|
|
*/
|
|
|
|
#include "polarssl/config.h"
|
|
|
|
#if defined(POLARSSL_CTR_DRBG_C)
|
|
|
|
#include "polarssl/ctr_drbg.h"
|
|
|
|
#if defined(POLARSSL_FS_IO)
|
|
#include <stdio.h>
|
|
#endif
|
|
|
|
#if defined(POLARSSL_PLATFORM_C)
|
|
#include "polarssl/platform.h"
|
|
#else
|
|
#define polarssl_printf printf
|
|
#endif
|
|
|
|
/*
|
|
* Non-public function wrapped by ctr_crbg_init(). Necessary to allow NIST
|
|
* tests to succeed (which require known length fixed entropy)
|
|
*/
|
|
int ctr_drbg_init_entropy_len(
|
|
ctr_drbg_context *ctx,
|
|
int (*f_entropy)(void *, unsigned char *, size_t),
|
|
void *p_entropy,
|
|
const unsigned char *custom,
|
|
size_t len,
|
|
size_t entropy_len )
|
|
{
|
|
int ret;
|
|
unsigned char key[CTR_DRBG_KEYSIZE];
|
|
|
|
memset( ctx, 0, sizeof(ctr_drbg_context) );
|
|
memset( key, 0, CTR_DRBG_KEYSIZE );
|
|
|
|
ctx->f_entropy = f_entropy;
|
|
ctx->p_entropy = p_entropy;
|
|
|
|
ctx->entropy_len = entropy_len;
|
|
ctx->reseed_interval = CTR_DRBG_RESEED_INTERVAL;
|
|
|
|
/*
|
|
* Initialize with an empty key
|
|
*/
|
|
aes_setkey_enc( &ctx->aes_ctx, key, CTR_DRBG_KEYBITS );
|
|
|
|
if( ( ret = ctr_drbg_reseed( ctx, custom, len ) ) != 0 )
|
|
return( ret );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int ctr_drbg_init( ctr_drbg_context *ctx,
|
|
int (*f_entropy)(void *, unsigned char *, size_t),
|
|
void *p_entropy,
|
|
const unsigned char *custom,
|
|
size_t len )
|
|
{
|
|
return( ctr_drbg_init_entropy_len( ctx, f_entropy, p_entropy, custom, len,
|
|
CTR_DRBG_ENTROPY_LEN ) );
|
|
}
|
|
|
|
void ctr_drbg_set_prediction_resistance( ctr_drbg_context *ctx, int resistance )
|
|
{
|
|
ctx->prediction_resistance = resistance;
|
|
}
|
|
|
|
void ctr_drbg_set_entropy_len( ctr_drbg_context *ctx, size_t len )
|
|
{
|
|
ctx->entropy_len = len;
|
|
}
|
|
|
|
void ctr_drbg_set_reseed_interval( ctr_drbg_context *ctx, int interval )
|
|
{
|
|
ctx->reseed_interval = interval;
|
|
}
|
|
|
|
static int block_cipher_df( unsigned char *output,
|
|
const unsigned char *data, size_t data_len )
|
|
{
|
|
unsigned char buf[CTR_DRBG_MAX_SEED_INPUT + CTR_DRBG_BLOCKSIZE + 16];
|
|
unsigned char tmp[CTR_DRBG_SEEDLEN];
|
|
unsigned char key[CTR_DRBG_KEYSIZE];
|
|
unsigned char chain[CTR_DRBG_BLOCKSIZE];
|
|
unsigned char *p, *iv;
|
|
aes_context aes_ctx;
|
|
|
|
int i, j;
|
|
size_t buf_len, use_len;
|
|
|
|
memset( buf, 0, CTR_DRBG_MAX_SEED_INPUT + CTR_DRBG_BLOCKSIZE + 16 );
|
|
|
|
/*
|
|
* Construct IV (16 bytes) and S in buffer
|
|
* IV = Counter (in 32-bits) padded to 16 with zeroes
|
|
* S = Length input string (in 32-bits) || Length of output (in 32-bits) ||
|
|
* data || 0x80
|
|
* (Total is padded to a multiple of 16-bytes with zeroes)
|
|
*/
|
|
p = buf + CTR_DRBG_BLOCKSIZE;
|
|
*p++ = ( data_len >> 24 ) & 0xff;
|
|
*p++ = ( data_len >> 16 ) & 0xff;
|
|
*p++ = ( data_len >> 8 ) & 0xff;
|
|
*p++ = ( data_len ) & 0xff;
|
|
p += 3;
|
|
*p++ = CTR_DRBG_SEEDLEN;
|
|
memcpy( p, data, data_len );
|
|
p[data_len] = 0x80;
|
|
|
|
buf_len = CTR_DRBG_BLOCKSIZE + 8 + data_len + 1;
|
|
|
|
for( i = 0; i < CTR_DRBG_KEYSIZE; i++ )
|
|
key[i] = i;
|
|
|
|
aes_setkey_enc( &aes_ctx, key, CTR_DRBG_KEYBITS );
|
|
|
|
/*
|
|
* Reduce data to POLARSSL_CTR_DRBG_SEEDLEN bytes of data
|
|
*/
|
|
for( j = 0; j < CTR_DRBG_SEEDLEN; j += CTR_DRBG_BLOCKSIZE )
|
|
{
|
|
p = buf;
|
|
memset( chain, 0, CTR_DRBG_BLOCKSIZE );
|
|
use_len = buf_len;
|
|
|
|
while( use_len > 0 )
|
|
{
|
|
for( i = 0; i < CTR_DRBG_BLOCKSIZE; i++ )
|
|
chain[i] ^= p[i];
|
|
p += CTR_DRBG_BLOCKSIZE;
|
|
use_len -= ( use_len >= CTR_DRBG_BLOCKSIZE ) ?
|
|
CTR_DRBG_BLOCKSIZE : use_len;
|
|
|
|
aes_crypt_ecb( &aes_ctx, AES_ENCRYPT, chain, chain );
|
|
}
|
|
|
|
memcpy( tmp + j, chain, CTR_DRBG_BLOCKSIZE );
|
|
|
|
/*
|
|
* Update IV
|
|
*/
|
|
buf[3]++;
|
|
}
|
|
|
|
/*
|
|
* Do final encryption with reduced data
|
|
*/
|
|
aes_setkey_enc( &aes_ctx, tmp, CTR_DRBG_KEYBITS );
|
|
iv = tmp + CTR_DRBG_KEYSIZE;
|
|
p = output;
|
|
|
|
for( j = 0; j < CTR_DRBG_SEEDLEN; j += CTR_DRBG_BLOCKSIZE )
|
|
{
|
|
aes_crypt_ecb( &aes_ctx, AES_ENCRYPT, iv, iv );
|
|
memcpy( p, iv, CTR_DRBG_BLOCKSIZE );
|
|
p += CTR_DRBG_BLOCKSIZE;
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
static int ctr_drbg_update_internal( ctr_drbg_context *ctx,
|
|
const unsigned char data[CTR_DRBG_SEEDLEN] )
|
|
{
|
|
unsigned char tmp[CTR_DRBG_SEEDLEN];
|
|
unsigned char *p = tmp;
|
|
int i, j;
|
|
|
|
memset( tmp, 0, CTR_DRBG_SEEDLEN );
|
|
|
|
for( j = 0; j < CTR_DRBG_SEEDLEN; j += CTR_DRBG_BLOCKSIZE )
|
|
{
|
|
/*
|
|
* Increase counter
|
|
*/
|
|
for( i = CTR_DRBG_BLOCKSIZE; i > 0; i-- )
|
|
if( ++ctx->counter[i - 1] != 0 )
|
|
break;
|
|
|
|
/*
|
|
* Crypt counter block
|
|
*/
|
|
aes_crypt_ecb( &ctx->aes_ctx, AES_ENCRYPT, ctx->counter, p );
|
|
|
|
p += CTR_DRBG_BLOCKSIZE;
|
|
}
|
|
|
|
for( i = 0; i < CTR_DRBG_SEEDLEN; i++ )
|
|
tmp[i] ^= data[i];
|
|
|
|
/*
|
|
* Update key and counter
|
|
*/
|
|
aes_setkey_enc( &ctx->aes_ctx, tmp, CTR_DRBG_KEYBITS );
|
|
memcpy( ctx->counter, tmp + CTR_DRBG_KEYSIZE, CTR_DRBG_BLOCKSIZE );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
void ctr_drbg_update( ctr_drbg_context *ctx,
|
|
const unsigned char *additional, size_t add_len )
|
|
{
|
|
unsigned char add_input[CTR_DRBG_SEEDLEN];
|
|
|
|
if( add_len > 0 )
|
|
{
|
|
block_cipher_df( add_input, additional, add_len );
|
|
ctr_drbg_update_internal( ctx, add_input );
|
|
}
|
|
}
|
|
|
|
int ctr_drbg_reseed( ctr_drbg_context *ctx,
|
|
const unsigned char *additional, size_t len )
|
|
{
|
|
unsigned char seed[CTR_DRBG_MAX_SEED_INPUT];
|
|
size_t seedlen = 0;
|
|
|
|
if( ctx->entropy_len + len > CTR_DRBG_MAX_SEED_INPUT )
|
|
return( POLARSSL_ERR_CTR_DRBG_INPUT_TOO_BIG );
|
|
|
|
memset( seed, 0, CTR_DRBG_MAX_SEED_INPUT );
|
|
|
|
/*
|
|
* Gather entropy_len bytes of entropy to seed state
|
|
*/
|
|
if( 0 != ctx->f_entropy( ctx->p_entropy, seed,
|
|
ctx->entropy_len ) )
|
|
{
|
|
return( POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED );
|
|
}
|
|
|
|
seedlen += ctx->entropy_len;
|
|
|
|
/*
|
|
* Add additional data
|
|
*/
|
|
if( additional && len )
|
|
{
|
|
memcpy( seed + seedlen, additional, len );
|
|
seedlen += len;
|
|
}
|
|
|
|
/*
|
|
* Reduce to 384 bits
|
|
*/
|
|
block_cipher_df( seed, seed, seedlen );
|
|
|
|
/*
|
|
* Update state
|
|
*/
|
|
ctr_drbg_update_internal( ctx, seed );
|
|
ctx->reseed_counter = 1;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int ctr_drbg_random_with_add( void *p_rng,
|
|
unsigned char *output, size_t output_len,
|
|
const unsigned char *additional, size_t add_len )
|
|
{
|
|
int ret = 0;
|
|
ctr_drbg_context *ctx = (ctr_drbg_context *) p_rng;
|
|
unsigned char add_input[CTR_DRBG_SEEDLEN];
|
|
unsigned char *p = output;
|
|
unsigned char tmp[CTR_DRBG_BLOCKSIZE];
|
|
int i;
|
|
size_t use_len;
|
|
|
|
if( output_len > CTR_DRBG_MAX_REQUEST )
|
|
return( POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG );
|
|
|
|
if( add_len > CTR_DRBG_MAX_INPUT )
|
|
return( POLARSSL_ERR_CTR_DRBG_INPUT_TOO_BIG );
|
|
|
|
memset( add_input, 0, CTR_DRBG_SEEDLEN );
|
|
|
|
if( ctx->reseed_counter > ctx->reseed_interval ||
|
|
ctx->prediction_resistance )
|
|
{
|
|
if( ( ret = ctr_drbg_reseed( ctx, additional, add_len ) ) != 0 )
|
|
return( ret );
|
|
|
|
add_len = 0;
|
|
}
|
|
|
|
if( add_len > 0 )
|
|
{
|
|
block_cipher_df( add_input, additional, add_len );
|
|
ctr_drbg_update_internal( ctx, add_input );
|
|
}
|
|
|
|
while( output_len > 0 )
|
|
{
|
|
/*
|
|
* Increase counter
|
|
*/
|
|
for( i = CTR_DRBG_BLOCKSIZE; i > 0; i-- )
|
|
if( ++ctx->counter[i - 1] != 0 )
|
|
break;
|
|
|
|
/*
|
|
* Crypt counter block
|
|
*/
|
|
aes_crypt_ecb( &ctx->aes_ctx, AES_ENCRYPT, ctx->counter, tmp );
|
|
|
|
use_len = (output_len > CTR_DRBG_BLOCKSIZE ) ? CTR_DRBG_BLOCKSIZE : output_len;
|
|
/*
|
|
* Copy random block to destination
|
|
*/
|
|
memcpy( p, tmp, use_len );
|
|
p += use_len;
|
|
output_len -= use_len;
|
|
}
|
|
|
|
ctr_drbg_update_internal( ctx, add_input );
|
|
|
|
ctx->reseed_counter++;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int ctr_drbg_random( void *p_rng, unsigned char *output, size_t output_len )
|
|
{
|
|
return ctr_drbg_random_with_add( p_rng, output, output_len, NULL, 0 );
|
|
}
|
|
|
|
#if defined(POLARSSL_FS_IO)
|
|
int ctr_drbg_write_seed_file( ctr_drbg_context *ctx, const char *path )
|
|
{
|
|
int ret = POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR;
|
|
FILE *f;
|
|
unsigned char buf[ CTR_DRBG_MAX_INPUT ];
|
|
|
|
if( ( f = fopen( path, "wb" ) ) == NULL )
|
|
return( POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR );
|
|
|
|
if( ( ret = ctr_drbg_random( ctx, buf, CTR_DRBG_MAX_INPUT ) ) != 0 )
|
|
goto exit;
|
|
|
|
if( fwrite( buf, 1, CTR_DRBG_MAX_INPUT, f ) != CTR_DRBG_MAX_INPUT )
|
|
{
|
|
ret = POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR; /* LCOV_EXCL_LINE */
|
|
goto exit; /* LCOV_EXCL_LINE */
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
exit:
|
|
fclose( f );
|
|
return( ret );
|
|
}
|
|
|
|
int ctr_drbg_update_seed_file( ctr_drbg_context *ctx, const char *path )
|
|
{
|
|
FILE *f;
|
|
size_t n;
|
|
unsigned char buf[ CTR_DRBG_MAX_INPUT ];
|
|
|
|
if( ( f = fopen( path, "rb" ) ) == NULL )
|
|
return( POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR );
|
|
|
|
fseek( f, 0, SEEK_END );
|
|
n = (size_t) ftell( f );
|
|
fseek( f, 0, SEEK_SET );
|
|
|
|
if( n > CTR_DRBG_MAX_INPUT )
|
|
{
|
|
fclose( f );
|
|
return( POLARSSL_ERR_CTR_DRBG_INPUT_TOO_BIG );
|
|
}
|
|
|
|
if( fread( buf, 1, n, f ) != n )
|
|
{
|
|
fclose( f ); /* LCOV_EXCL_LINE */
|
|
return( POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR ); /* LCOV_EXCL_LINE */
|
|
}
|
|
|
|
fclose( f );
|
|
|
|
ctr_drbg_update( ctx, buf, n );
|
|
|
|
return( ctr_drbg_write_seed_file( ctx, path ) );
|
|
}
|
|
#endif /* POLARSSL_FS_IO */
|
|
|
|
#if defined(POLARSSL_SELF_TEST)
|
|
|
|
#include <stdio.h>
|
|
|
|
static unsigned char entropy_source_pr[96] =
|
|
{ 0xc1, 0x80, 0x81, 0xa6, 0x5d, 0x44, 0x02, 0x16,
|
|
0x19, 0xb3, 0xf1, 0x80, 0xb1, 0xc9, 0x20, 0x02,
|
|
0x6a, 0x54, 0x6f, 0x0c, 0x70, 0x81, 0x49, 0x8b,
|
|
0x6e, 0xa6, 0x62, 0x52, 0x6d, 0x51, 0xb1, 0xcb,
|
|
0x58, 0x3b, 0xfa, 0xd5, 0x37, 0x5f, 0xfb, 0xc9,
|
|
0xff, 0x46, 0xd2, 0x19, 0xc7, 0x22, 0x3e, 0x95,
|
|
0x45, 0x9d, 0x82, 0xe1, 0xe7, 0x22, 0x9f, 0x63,
|
|
0x31, 0x69, 0xd2, 0x6b, 0x57, 0x47, 0x4f, 0xa3,
|
|
0x37, 0xc9, 0x98, 0x1c, 0x0b, 0xfb, 0x91, 0x31,
|
|
0x4d, 0x55, 0xb9, 0xe9, 0x1c, 0x5a, 0x5e, 0xe4,
|
|
0x93, 0x92, 0xcf, 0xc5, 0x23, 0x12, 0xd5, 0x56,
|
|
0x2c, 0x4a, 0x6e, 0xff, 0xdc, 0x10, 0xd0, 0x68 };
|
|
|
|
static unsigned char entropy_source_nopr[64] =
|
|
{ 0x5a, 0x19, 0x4d, 0x5e, 0x2b, 0x31, 0x58, 0x14,
|
|
0x54, 0xde, 0xf6, 0x75, 0xfb, 0x79, 0x58, 0xfe,
|
|
0xc7, 0xdb, 0x87, 0x3e, 0x56, 0x89, 0xfc, 0x9d,
|
|
0x03, 0x21, 0x7c, 0x68, 0xd8, 0x03, 0x38, 0x20,
|
|
0xf9, 0xe6, 0x5e, 0x04, 0xd8, 0x56, 0xf3, 0xa9,
|
|
0xc4, 0x4a, 0x4c, 0xbd, 0xc1, 0xd0, 0x08, 0x46,
|
|
0xf5, 0x98, 0x3d, 0x77, 0x1c, 0x1b, 0x13, 0x7e,
|
|
0x4e, 0x0f, 0x9d, 0x8e, 0xf4, 0x09, 0xf9, 0x2e };
|
|
|
|
static const unsigned char nonce_pers_pr[16] =
|
|
{ 0xd2, 0x54, 0xfc, 0xff, 0x02, 0x1e, 0x69, 0xd2,
|
|
0x29, 0xc9, 0xcf, 0xad, 0x85, 0xfa, 0x48, 0x6c };
|
|
|
|
static const unsigned char nonce_pers_nopr[16] =
|
|
{ 0x1b, 0x54, 0xb8, 0xff, 0x06, 0x42, 0xbf, 0xf5,
|
|
0x21, 0xf1, 0x5c, 0x1c, 0x0b, 0x66, 0x5f, 0x3f };
|
|
|
|
static const unsigned char result_pr[16] =
|
|
{ 0x34, 0x01, 0x16, 0x56, 0xb4, 0x29, 0x00, 0x8f,
|
|
0x35, 0x63, 0xec, 0xb5, 0xf2, 0x59, 0x07, 0x23 };
|
|
|
|
static const unsigned char result_nopr[16] =
|
|
{ 0xa0, 0x54, 0x30, 0x3d, 0x8a, 0x7e, 0xa9, 0x88,
|
|
0x9d, 0x90, 0x3e, 0x07, 0x7c, 0x6f, 0x21, 0x8f };
|
|
|
|
static int test_offset;
|
|
static int ctr_drbg_self_test_entropy( void *data, unsigned char *buf,
|
|
size_t len )
|
|
{
|
|
const unsigned char *p = data;
|
|
memcpy( buf, p + test_offset, len );
|
|
test_offset += len;
|
|
return( 0 );
|
|
}
|
|
|
|
#define CHK( c ) if( (c) != 0 ) \
|
|
{ \
|
|
if( verbose != 0 ) \
|
|
polarssl_printf( "failed\n" ); \
|
|
return( 1 ); \
|
|
}
|
|
|
|
/*
|
|
* Checkup routine
|
|
*/
|
|
int ctr_drbg_self_test( int verbose )
|
|
{
|
|
ctr_drbg_context ctx;
|
|
unsigned char buf[16];
|
|
|
|
/*
|
|
* Based on a NIST CTR_DRBG test vector (PR = True)
|
|
*/
|
|
if( verbose != 0 )
|
|
polarssl_printf( " CTR_DRBG (PR = TRUE) : " );
|
|
|
|
test_offset = 0;
|
|
CHK( ctr_drbg_init_entropy_len( &ctx, ctr_drbg_self_test_entropy,
|
|
entropy_source_pr, nonce_pers_pr, 16, 32 ) );
|
|
ctr_drbg_set_prediction_resistance( &ctx, CTR_DRBG_PR_ON );
|
|
CHK( ctr_drbg_random( &ctx, buf, CTR_DRBG_BLOCKSIZE ) );
|
|
CHK( ctr_drbg_random( &ctx, buf, CTR_DRBG_BLOCKSIZE ) );
|
|
CHK( memcmp( buf, result_pr, CTR_DRBG_BLOCKSIZE ) );
|
|
|
|
if( verbose != 0 )
|
|
polarssl_printf( "passed\n" );
|
|
|
|
/*
|
|
* Based on a NIST CTR_DRBG test vector (PR = FALSE)
|
|
*/
|
|
if( verbose != 0 )
|
|
polarssl_printf( " CTR_DRBG (PR = FALSE): " );
|
|
|
|
test_offset = 0;
|
|
CHK( ctr_drbg_init_entropy_len( &ctx, ctr_drbg_self_test_entropy,
|
|
entropy_source_nopr, nonce_pers_nopr, 16, 32 ) );
|
|
CHK( ctr_drbg_random( &ctx, buf, 16 ) );
|
|
CHK( ctr_drbg_reseed( &ctx, NULL, 0 ) );
|
|
CHK( ctr_drbg_random( &ctx, buf, 16 ) );
|
|
CHK( memcmp( buf, result_nopr, 16 ) );
|
|
|
|
if( verbose != 0 )
|
|
polarssl_printf( "passed\n" );
|
|
|
|
if( verbose != 0 )
|
|
polarssl_printf( "\n" );
|
|
|
|
return( 0 );
|
|
}
|
|
#endif
|
|
|
|
#endif
|