891 lines
29 KiB
C
891 lines
29 KiB
C
/*
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* CTR_DRBG implementation based on AES-256 (NIST SP 800-90)
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*
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* Copyright The Mbed TLS Contributors
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/*
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* The NIST SP 800-90 DRBGs are described in the following publication.
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*
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* http://csrc.nist.gov/publications/nistpubs/800-90/SP800-90revised_March2007.pdf
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*/
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#include "common.h"
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#if defined(MBEDTLS_CTR_DRBG_C)
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#include "mbedtls/ctr_drbg.h"
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#include "mbedtls/platform_util.h"
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#include "mbedtls/error.h"
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#include <string.h>
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#if defined(MBEDTLS_FS_IO)
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#include <stdio.h>
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#endif
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#include "mbedtls/platform.h"
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/*
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* CTR_DRBG context initialization
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*/
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void mbedtls_ctr_drbg_init( mbedtls_ctr_drbg_context *ctx )
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{
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memset( ctx, 0, sizeof( mbedtls_ctr_drbg_context ) );
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/* Indicate that the entropy nonce length is not set explicitly.
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* See mbedtls_ctr_drbg_set_nonce_len(). */
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ctx->reseed_counter = -1;
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ctx->reseed_interval = MBEDTLS_CTR_DRBG_RESEED_INTERVAL;
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}
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/*
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* This function resets CTR_DRBG context to the state immediately
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* after initial call of mbedtls_ctr_drbg_init().
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*/
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void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx )
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{
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if( ctx == NULL )
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return;
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#if defined(MBEDTLS_THREADING_C)
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/* The mutex is initialized iff f_entropy is set. */
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if( ctx->f_entropy != NULL )
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mbedtls_mutex_free( &ctx->mutex );
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#endif
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mbedtls_aes_free( &ctx->aes_ctx );
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mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ctr_drbg_context ) );
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ctx->reseed_interval = MBEDTLS_CTR_DRBG_RESEED_INTERVAL;
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ctx->reseed_counter = -1;
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}
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void mbedtls_ctr_drbg_set_prediction_resistance( mbedtls_ctr_drbg_context *ctx,
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int resistance )
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{
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ctx->prediction_resistance = resistance;
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}
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void mbedtls_ctr_drbg_set_entropy_len( mbedtls_ctr_drbg_context *ctx,
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size_t len )
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{
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ctx->entropy_len = len;
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}
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int mbedtls_ctr_drbg_set_nonce_len( mbedtls_ctr_drbg_context *ctx,
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size_t len )
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{
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/* If mbedtls_ctr_drbg_seed() has already been called, it's
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* too late. Return the error code that's closest to making sense. */
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if( ctx->f_entropy != NULL )
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return( MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED );
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if( len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
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return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
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#if SIZE_MAX > INT_MAX
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/* This shouldn't be an issue because
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* MBEDTLS_CTR_DRBG_MAX_SEED_INPUT < INT_MAX in any sensible
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* configuration, but make sure anyway. */
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if( len > INT_MAX )
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return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
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#endif
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/* For backward compatibility with Mbed TLS <= 2.19, store the
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* entropy nonce length in a field that already exists, but isn't
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* used until after the initial seeding. */
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/* Due to the capping of len above, the value fits in an int. */
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ctx->reseed_counter = (int) len;
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return( 0 );
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}
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void mbedtls_ctr_drbg_set_reseed_interval( mbedtls_ctr_drbg_context *ctx,
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int interval )
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{
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ctx->reseed_interval = interval;
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}
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static int block_cipher_df( unsigned char *output,
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const unsigned char *data, size_t data_len )
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{
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unsigned char buf[MBEDTLS_CTR_DRBG_MAX_SEED_INPUT +
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MBEDTLS_CTR_DRBG_BLOCKSIZE + 16];
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unsigned char tmp[MBEDTLS_CTR_DRBG_SEEDLEN];
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unsigned char key[MBEDTLS_CTR_DRBG_KEYSIZE];
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unsigned char chain[MBEDTLS_CTR_DRBG_BLOCKSIZE];
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unsigned char *p, *iv;
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mbedtls_aes_context aes_ctx;
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int ret = 0;
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int i, j;
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size_t buf_len, use_len;
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if( data_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
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return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
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memset( buf, 0, MBEDTLS_CTR_DRBG_MAX_SEED_INPUT +
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MBEDTLS_CTR_DRBG_BLOCKSIZE + 16 );
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mbedtls_aes_init( &aes_ctx );
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/*
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* Construct IV (16 bytes) and S in buffer
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* IV = Counter (in 32-bits) padded to 16 with zeroes
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* S = Length input string (in 32-bits) || Length of output (in 32-bits) ||
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* data || 0x80
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* (Total is padded to a multiple of 16-bytes with zeroes)
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*/
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p = buf + MBEDTLS_CTR_DRBG_BLOCKSIZE;
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MBEDTLS_PUT_UINT32_BE( data_len, p, 0);
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p += 4 + 3;
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*p++ = MBEDTLS_CTR_DRBG_SEEDLEN;
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memcpy( p, data, data_len );
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p[data_len] = 0x80;
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buf_len = MBEDTLS_CTR_DRBG_BLOCKSIZE + 8 + data_len + 1;
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for( i = 0; i < MBEDTLS_CTR_DRBG_KEYSIZE; i++ )
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key[i] = i;
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if( ( ret = mbedtls_aes_setkey_enc( &aes_ctx, key,
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MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
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{
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goto exit;
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}
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/*
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* Reduce data to MBEDTLS_CTR_DRBG_SEEDLEN bytes of data
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*/
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for( j = 0; j < MBEDTLS_CTR_DRBG_SEEDLEN; j += MBEDTLS_CTR_DRBG_BLOCKSIZE )
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{
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p = buf;
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memset( chain, 0, MBEDTLS_CTR_DRBG_BLOCKSIZE );
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use_len = buf_len;
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while( use_len > 0 )
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{
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for( i = 0; i < MBEDTLS_CTR_DRBG_BLOCKSIZE; i++ )
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chain[i] ^= p[i];
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p += MBEDTLS_CTR_DRBG_BLOCKSIZE;
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use_len -= ( use_len >= MBEDTLS_CTR_DRBG_BLOCKSIZE ) ?
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MBEDTLS_CTR_DRBG_BLOCKSIZE : use_len;
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if( ( ret = mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT,
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chain, chain ) ) != 0 )
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{
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goto exit;
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}
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}
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memcpy( tmp + j, chain, MBEDTLS_CTR_DRBG_BLOCKSIZE );
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/*
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* Update IV
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*/
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buf[3]++;
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}
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/*
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* Do final encryption with reduced data
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*/
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if( ( ret = mbedtls_aes_setkey_enc( &aes_ctx, tmp,
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MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
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{
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goto exit;
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}
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iv = tmp + MBEDTLS_CTR_DRBG_KEYSIZE;
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p = output;
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for( j = 0; j < MBEDTLS_CTR_DRBG_SEEDLEN; j += MBEDTLS_CTR_DRBG_BLOCKSIZE )
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{
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if( ( ret = mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT,
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iv, iv ) ) != 0 )
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{
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goto exit;
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}
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memcpy( p, iv, MBEDTLS_CTR_DRBG_BLOCKSIZE );
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p += MBEDTLS_CTR_DRBG_BLOCKSIZE;
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}
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exit:
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mbedtls_aes_free( &aes_ctx );
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/*
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* tidy up the stack
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*/
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mbedtls_platform_zeroize( buf, sizeof( buf ) );
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mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
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mbedtls_platform_zeroize( key, sizeof( key ) );
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mbedtls_platform_zeroize( chain, sizeof( chain ) );
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if( 0 != ret )
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{
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/*
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* wipe partial seed from memory
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*/
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mbedtls_platform_zeroize( output, MBEDTLS_CTR_DRBG_SEEDLEN );
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}
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return( ret );
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}
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/* CTR_DRBG_Update (SP 800-90A §10.2.1.2)
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* ctr_drbg_update_internal(ctx, provided_data)
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* implements
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* CTR_DRBG_Update(provided_data, Key, V)
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* with inputs and outputs
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* ctx->aes_ctx = Key
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* ctx->counter = V
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*/
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static int ctr_drbg_update_internal( mbedtls_ctr_drbg_context *ctx,
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const unsigned char data[MBEDTLS_CTR_DRBG_SEEDLEN] )
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{
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unsigned char tmp[MBEDTLS_CTR_DRBG_SEEDLEN];
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unsigned char *p = tmp;
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int i, j;
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int ret = 0;
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memset( tmp, 0, MBEDTLS_CTR_DRBG_SEEDLEN );
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for( j = 0; j < MBEDTLS_CTR_DRBG_SEEDLEN; j += MBEDTLS_CTR_DRBG_BLOCKSIZE )
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{
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/*
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* Increase counter
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*/
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for( i = MBEDTLS_CTR_DRBG_BLOCKSIZE; i > 0; i-- )
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if( ++ctx->counter[i - 1] != 0 )
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break;
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/*
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* Crypt counter block
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*/
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if( ( ret = mbedtls_aes_crypt_ecb( &ctx->aes_ctx, MBEDTLS_AES_ENCRYPT,
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ctx->counter, p ) ) != 0 )
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{
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goto exit;
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}
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p += MBEDTLS_CTR_DRBG_BLOCKSIZE;
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}
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for( i = 0; i < MBEDTLS_CTR_DRBG_SEEDLEN; i++ )
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tmp[i] ^= data[i];
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/*
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* Update key and counter
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*/
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if( ( ret = mbedtls_aes_setkey_enc( &ctx->aes_ctx, tmp,
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MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
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{
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goto exit;
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}
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memcpy( ctx->counter, tmp + MBEDTLS_CTR_DRBG_KEYSIZE,
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MBEDTLS_CTR_DRBG_BLOCKSIZE );
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exit:
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mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
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return( ret );
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}
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/* CTR_DRBG_Instantiate with derivation function (SP 800-90A §10.2.1.3.2)
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* mbedtls_ctr_drbg_update(ctx, additional, add_len)
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* implements
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* CTR_DRBG_Instantiate(entropy_input, nonce, personalization_string,
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* security_strength) -> initial_working_state
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* with inputs
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* ctx->counter = all-bits-0
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* ctx->aes_ctx = context from all-bits-0 key
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* additional[:add_len] = entropy_input || nonce || personalization_string
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* and with outputs
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* ctx = initial_working_state
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*/
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int mbedtls_ctr_drbg_update_ret( mbedtls_ctr_drbg_context *ctx,
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const unsigned char *additional,
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size_t add_len )
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{
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unsigned char add_input[MBEDTLS_CTR_DRBG_SEEDLEN];
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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if( add_len == 0 )
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return( 0 );
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if( ( ret = block_cipher_df( add_input, additional, add_len ) ) != 0 )
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goto exit;
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if( ( ret = ctr_drbg_update_internal( ctx, add_input ) ) != 0 )
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goto exit;
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exit:
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mbedtls_platform_zeroize( add_input, sizeof( add_input ) );
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return( ret );
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}
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#if !defined(MBEDTLS_DEPRECATED_REMOVED)
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void mbedtls_ctr_drbg_update( mbedtls_ctr_drbg_context *ctx,
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const unsigned char *additional,
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size_t add_len )
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{
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/* MAX_INPUT would be more logical here, but we have to match
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* block_cipher_df()'s limits since we can't propagate errors */
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if( add_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
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add_len = MBEDTLS_CTR_DRBG_MAX_SEED_INPUT;
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(void) mbedtls_ctr_drbg_update_ret( ctx, additional, add_len );
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}
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#endif /* MBEDTLS_DEPRECATED_REMOVED */
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/* CTR_DRBG_Reseed with derivation function (SP 800-90A §10.2.1.4.2)
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* mbedtls_ctr_drbg_reseed(ctx, additional, len, nonce_len)
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* implements
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* CTR_DRBG_Reseed(working_state, entropy_input, additional_input)
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* -> new_working_state
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* with inputs
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* ctx contains working_state
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* additional[:len] = additional_input
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* and entropy_input comes from calling ctx->f_entropy
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* for (ctx->entropy_len + nonce_len) bytes
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* and with output
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* ctx contains new_working_state
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*/
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static int mbedtls_ctr_drbg_reseed_internal( mbedtls_ctr_drbg_context *ctx,
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const unsigned char *additional,
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size_t len,
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size_t nonce_len )
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{
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unsigned char seed[MBEDTLS_CTR_DRBG_MAX_SEED_INPUT];
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size_t seedlen = 0;
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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if( ctx->entropy_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
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return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
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if( nonce_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT - ctx->entropy_len )
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return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
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if( len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT - ctx->entropy_len - nonce_len )
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return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
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memset( seed, 0, MBEDTLS_CTR_DRBG_MAX_SEED_INPUT );
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/* Gather entropy_len bytes of entropy to seed state. */
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if( 0 != ctx->f_entropy( ctx->p_entropy, seed, ctx->entropy_len ) )
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{
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return( MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED );
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}
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seedlen += ctx->entropy_len;
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/* Gather entropy for a nonce if requested. */
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if( nonce_len != 0 )
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{
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if( 0 != ctx->f_entropy( ctx->p_entropy, seed + seedlen, nonce_len ) )
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{
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return( MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED );
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}
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seedlen += nonce_len;
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}
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/* Add additional data if provided. */
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if( additional != NULL && len != 0 )
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{
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memcpy( seed + seedlen, additional, len );
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seedlen += len;
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}
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/* Reduce to 384 bits. */
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if( ( ret = block_cipher_df( seed, seed, seedlen ) ) != 0 )
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goto exit;
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/* Update state. */
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if( ( ret = ctr_drbg_update_internal( ctx, seed ) ) != 0 )
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goto exit;
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ctx->reseed_counter = 1;
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exit:
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mbedtls_platform_zeroize( seed, sizeof( seed ) );
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return( ret );
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}
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int mbedtls_ctr_drbg_reseed( mbedtls_ctr_drbg_context *ctx,
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const unsigned char *additional, size_t len )
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{
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return( mbedtls_ctr_drbg_reseed_internal( ctx, additional, len, 0 ) );
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}
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/* Return a "good" nonce length for CTR_DRBG. The chosen nonce length
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* is sufficient to achieve the maximum security strength given the key
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* size and entropy length. If there is enough entropy in the initial
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* call to the entropy function to serve as both the entropy input and
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* the nonce, don't make a second call to get a nonce. */
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static size_t good_nonce_len( size_t entropy_len )
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{
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if( entropy_len >= MBEDTLS_CTR_DRBG_KEYSIZE * 3 / 2 )
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return( 0 );
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else
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return( ( entropy_len + 1 ) / 2 );
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}
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/* CTR_DRBG_Instantiate with derivation function (SP 800-90A §10.2.1.3.2)
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* mbedtls_ctr_drbg_seed(ctx, f_entropy, p_entropy, custom, len)
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* implements
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* CTR_DRBG_Instantiate(entropy_input, nonce, personalization_string,
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* security_strength) -> initial_working_state
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* with inputs
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* custom[:len] = nonce || personalization_string
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* where entropy_input comes from f_entropy for ctx->entropy_len bytes
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* and with outputs
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* ctx = initial_working_state
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*/
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int mbedtls_ctr_drbg_seed( mbedtls_ctr_drbg_context *ctx,
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int (*f_entropy)(void *, unsigned char *, size_t),
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void *p_entropy,
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const unsigned char *custom,
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size_t len )
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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unsigned char key[MBEDTLS_CTR_DRBG_KEYSIZE];
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size_t nonce_len;
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memset( key, 0, MBEDTLS_CTR_DRBG_KEYSIZE );
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/* The mutex is initialized iff f_entropy is set. */
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#if defined(MBEDTLS_THREADING_C)
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mbedtls_mutex_init( &ctx->mutex );
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#endif
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mbedtls_aes_init( &ctx->aes_ctx );
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ctx->f_entropy = f_entropy;
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ctx->p_entropy = p_entropy;
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if( ctx->entropy_len == 0 )
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ctx->entropy_len = MBEDTLS_CTR_DRBG_ENTROPY_LEN;
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/* ctx->reseed_counter contains the desired amount of entropy to
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* grab for a nonce (see mbedtls_ctr_drbg_set_nonce_len()).
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* If it's -1, indicating that the entropy nonce length was not set
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* explicitly, use a sufficiently large nonce for security. */
|
|
nonce_len = ( ctx->reseed_counter >= 0 ?
|
|
(size_t) ctx->reseed_counter :
|
|
good_nonce_len( ctx->entropy_len ) );
|
|
|
|
/* Initialize with an empty key. */
|
|
if( ( ret = mbedtls_aes_setkey_enc( &ctx->aes_ctx, key,
|
|
MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
|
|
{
|
|
return( ret );
|
|
}
|
|
|
|
/* Do the initial seeding. */
|
|
if( ( ret = mbedtls_ctr_drbg_reseed_internal( ctx, custom, len,
|
|
nonce_len ) ) != 0 )
|
|
{
|
|
return( ret );
|
|
}
|
|
return( 0 );
|
|
}
|
|
|
|
/* CTR_DRBG_Generate with derivation function (SP 800-90A §10.2.1.5.2)
|
|
* mbedtls_ctr_drbg_random_with_add(ctx, output, output_len, additional, add_len)
|
|
* implements
|
|
* CTR_DRBG_Reseed(working_state, entropy_input, additional[:add_len])
|
|
* -> working_state_after_reseed
|
|
* if required, then
|
|
* CTR_DRBG_Generate(working_state_after_reseed,
|
|
* requested_number_of_bits, additional_input)
|
|
* -> status, returned_bits, new_working_state
|
|
* with inputs
|
|
* ctx contains working_state
|
|
* requested_number_of_bits = 8 * output_len
|
|
* additional[:add_len] = additional_input
|
|
* and entropy_input comes from calling ctx->f_entropy
|
|
* and with outputs
|
|
* status = SUCCESS (this function does the reseed internally)
|
|
* returned_bits = output[:output_len]
|
|
* ctx contains new_working_state
|
|
*/
|
|
int mbedtls_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;
|
|
mbedtls_ctr_drbg_context *ctx = (mbedtls_ctr_drbg_context *) p_rng;
|
|
unsigned char add_input[MBEDTLS_CTR_DRBG_SEEDLEN];
|
|
unsigned char *p = output;
|
|
unsigned char tmp[MBEDTLS_CTR_DRBG_BLOCKSIZE];
|
|
int i;
|
|
size_t use_len;
|
|
|
|
if( output_len > MBEDTLS_CTR_DRBG_MAX_REQUEST )
|
|
return( MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG );
|
|
|
|
if( add_len > MBEDTLS_CTR_DRBG_MAX_INPUT )
|
|
return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
|
|
|
|
memset( add_input, 0, MBEDTLS_CTR_DRBG_SEEDLEN );
|
|
|
|
if( ctx->reseed_counter > ctx->reseed_interval ||
|
|
ctx->prediction_resistance )
|
|
{
|
|
if( ( ret = mbedtls_ctr_drbg_reseed( ctx, additional, add_len ) ) != 0 )
|
|
{
|
|
return( ret );
|
|
}
|
|
add_len = 0;
|
|
}
|
|
|
|
if( add_len > 0 )
|
|
{
|
|
if( ( ret = block_cipher_df( add_input, additional, add_len ) ) != 0 )
|
|
goto exit;
|
|
if( ( ret = ctr_drbg_update_internal( ctx, add_input ) ) != 0 )
|
|
goto exit;
|
|
}
|
|
|
|
while( output_len > 0 )
|
|
{
|
|
/*
|
|
* Increase counter
|
|
*/
|
|
for( i = MBEDTLS_CTR_DRBG_BLOCKSIZE; i > 0; i-- )
|
|
if( ++ctx->counter[i - 1] != 0 )
|
|
break;
|
|
|
|
/*
|
|
* Crypt counter block
|
|
*/
|
|
if( ( ret = mbedtls_aes_crypt_ecb( &ctx->aes_ctx, MBEDTLS_AES_ENCRYPT,
|
|
ctx->counter, tmp ) ) != 0 )
|
|
{
|
|
goto exit;
|
|
}
|
|
|
|
use_len = ( output_len > MBEDTLS_CTR_DRBG_BLOCKSIZE )
|
|
? MBEDTLS_CTR_DRBG_BLOCKSIZE : output_len;
|
|
/*
|
|
* Copy random block to destination
|
|
*/
|
|
memcpy( p, tmp, use_len );
|
|
p += use_len;
|
|
output_len -= use_len;
|
|
}
|
|
|
|
if( ( ret = ctr_drbg_update_internal( ctx, add_input ) ) != 0 )
|
|
goto exit;
|
|
|
|
ctx->reseed_counter++;
|
|
|
|
exit:
|
|
mbedtls_platform_zeroize( add_input, sizeof( add_input ) );
|
|
mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
|
|
return( ret );
|
|
}
|
|
|
|
int mbedtls_ctr_drbg_random( void *p_rng, unsigned char *output,
|
|
size_t output_len )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
mbedtls_ctr_drbg_context *ctx = (mbedtls_ctr_drbg_context *) p_rng;
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
|
|
return( ret );
|
|
#endif
|
|
|
|
ret = mbedtls_ctr_drbg_random_with_add( ctx, output, output_len, NULL, 0 );
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
|
|
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
|
|
#endif
|
|
|
|
return( ret );
|
|
}
|
|
|
|
#if defined(MBEDTLS_FS_IO)
|
|
int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx,
|
|
const char *path )
|
|
{
|
|
int ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
|
|
FILE *f;
|
|
unsigned char buf[ MBEDTLS_CTR_DRBG_MAX_INPUT ];
|
|
|
|
if( ( f = fopen( path, "wb" ) ) == NULL )
|
|
return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
|
|
|
|
if( ( ret = mbedtls_ctr_drbg_random( ctx, buf,
|
|
MBEDTLS_CTR_DRBG_MAX_INPUT ) ) != 0 )
|
|
goto exit;
|
|
|
|
if( fwrite( buf, 1, MBEDTLS_CTR_DRBG_MAX_INPUT, f ) !=
|
|
MBEDTLS_CTR_DRBG_MAX_INPUT )
|
|
{
|
|
ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
|
|
}
|
|
else
|
|
{
|
|
ret = 0;
|
|
}
|
|
|
|
exit:
|
|
mbedtls_platform_zeroize( buf, sizeof( buf ) );
|
|
|
|
fclose( f );
|
|
return( ret );
|
|
}
|
|
|
|
int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx,
|
|
const char *path )
|
|
{
|
|
int ret = 0;
|
|
FILE *f = NULL;
|
|
size_t n;
|
|
unsigned char buf[ MBEDTLS_CTR_DRBG_MAX_INPUT ];
|
|
unsigned char c;
|
|
|
|
if( ( f = fopen( path, "rb" ) ) == NULL )
|
|
return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
|
|
|
|
n = fread( buf, 1, sizeof( buf ), f );
|
|
if( fread( &c, 1, 1, f ) != 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG;
|
|
goto exit;
|
|
}
|
|
if( n == 0 || ferror( f ) )
|
|
{
|
|
ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
|
|
goto exit;
|
|
}
|
|
fclose( f );
|
|
f = NULL;
|
|
|
|
ret = mbedtls_ctr_drbg_update_ret( ctx, buf, n );
|
|
|
|
exit:
|
|
mbedtls_platform_zeroize( buf, sizeof( buf ) );
|
|
if( f != NULL )
|
|
fclose( f );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
return( mbedtls_ctr_drbg_write_seed_file( ctx, path ) );
|
|
}
|
|
#endif /* MBEDTLS_FS_IO */
|
|
|
|
#if defined(MBEDTLS_SELF_TEST)
|
|
|
|
/* The CTR_DRBG NIST test vectors used here are available at
|
|
* https://csrc.nist.gov/CSRC/media/Projects/Cryptographic-Algorithm-Validation-Program/documents/drbg/drbgtestvectors.zip
|
|
*
|
|
* The parameters used to derive the test data are:
|
|
*
|
|
* [AES-128 use df]
|
|
* [PredictionResistance = True/False]
|
|
* [EntropyInputLen = 128]
|
|
* [NonceLen = 64]
|
|
* [PersonalizationStringLen = 128]
|
|
* [AdditionalInputLen = 0]
|
|
* [ReturnedBitsLen = 512]
|
|
*
|
|
* [AES-256 use df]
|
|
* [PredictionResistance = True/False]
|
|
* [EntropyInputLen = 256]
|
|
* [NonceLen = 128]
|
|
* [PersonalizationStringLen = 256]
|
|
* [AdditionalInputLen = 0]
|
|
* [ReturnedBitsLen = 512]
|
|
*
|
|
*/
|
|
|
|
#if defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
|
|
static const unsigned char entropy_source_pr[] =
|
|
{ 0x04, 0xd9, 0x49, 0xa6, 0xdc, 0xe8, 0x6e, 0xbb,
|
|
0xf1, 0x08, 0x77, 0x2b, 0x9e, 0x08, 0xca, 0x92,
|
|
0x65, 0x16, 0xda, 0x99, 0xa2, 0x59, 0xf3, 0xe8,
|
|
0x38, 0x7e, 0x3f, 0x6b, 0x51, 0x70, 0x7b, 0x20,
|
|
0xec, 0x53, 0xd0, 0x66, 0xc3, 0x0f, 0xe3, 0xb0,
|
|
0xe0, 0x86, 0xa6, 0xaa, 0x5f, 0x72, 0x2f, 0xad,
|
|
0xf7, 0xef, 0x06, 0xb8, 0xd6, 0x9c, 0x9d, 0xe8 };
|
|
|
|
static const unsigned char entropy_source_nopr[] =
|
|
{ 0x07, 0x0d, 0x59, 0x63, 0x98, 0x73, 0xa5, 0x45,
|
|
0x27, 0x38, 0x22, 0x7b, 0x76, 0x85, 0xd1, 0xa9,
|
|
0x74, 0x18, 0x1f, 0x3c, 0x22, 0xf6, 0x49, 0x20,
|
|
0x4a, 0x47, 0xc2, 0xf3, 0x85, 0x16, 0xb4, 0x6f,
|
|
0x00, 0x2e, 0x71, 0xda, 0xed, 0x16, 0x9b, 0x5c };
|
|
|
|
static const unsigned char pers_pr[] =
|
|
{ 0xbf, 0xa4, 0x9a, 0x8f, 0x7b, 0xd8, 0xb1, 0x7a,
|
|
0x9d, 0xfa, 0x45, 0xed, 0x21, 0x52, 0xb3, 0xad };
|
|
|
|
static const unsigned char pers_nopr[] =
|
|
{ 0x4e, 0x61, 0x79, 0xd4, 0xc2, 0x72, 0xa1, 0x4c,
|
|
0xf1, 0x3d, 0xf6, 0x5e, 0xa3, 0xa6, 0xe5, 0x0f };
|
|
|
|
static const unsigned char result_pr[] =
|
|
{ 0xc9, 0x0a, 0xaf, 0x85, 0x89, 0x71, 0x44, 0x66,
|
|
0x4f, 0x25, 0x0b, 0x2b, 0xde, 0xd8, 0xfa, 0xff,
|
|
0x52, 0x5a, 0x1b, 0x32, 0x5e, 0x41, 0x7a, 0x10,
|
|
0x1f, 0xef, 0x1e, 0x62, 0x23, 0xe9, 0x20, 0x30,
|
|
0xc9, 0x0d, 0xad, 0x69, 0xb4, 0x9c, 0x5b, 0xf4,
|
|
0x87, 0x42, 0xd5, 0xae, 0x5e, 0x5e, 0x43, 0xcc,
|
|
0xd9, 0xfd, 0x0b, 0x93, 0x4a, 0xe3, 0xd4, 0x06,
|
|
0x37, 0x36, 0x0f, 0x3f, 0x72, 0x82, 0x0c, 0xcf };
|
|
|
|
static const unsigned char result_nopr[] =
|
|
{ 0x31, 0xc9, 0x91, 0x09, 0xf8, 0xc5, 0x10, 0x13,
|
|
0x3c, 0xd3, 0x96, 0xf9, 0xbc, 0x2c, 0x12, 0xc0,
|
|
0x7c, 0xc1, 0x61, 0x5f, 0xa3, 0x09, 0x99, 0xaf,
|
|
0xd7, 0xf2, 0x36, 0xfd, 0x40, 0x1a, 0x8b, 0xf2,
|
|
0x33, 0x38, 0xee, 0x1d, 0x03, 0x5f, 0x83, 0xb7,
|
|
0xa2, 0x53, 0xdc, 0xee, 0x18, 0xfc, 0xa7, 0xf2,
|
|
0xee, 0x96, 0xc6, 0xc2, 0xcd, 0x0c, 0xff, 0x02,
|
|
0x76, 0x70, 0x69, 0xaa, 0x69, 0xd1, 0x3b, 0xe8 };
|
|
#else /* MBEDTLS_CTR_DRBG_USE_128_BIT_KEY */
|
|
|
|
static const unsigned char entropy_source_pr[] =
|
|
{ 0xca, 0x58, 0xfd, 0xf2, 0xb9, 0x77, 0xcb, 0x49,
|
|
0xd4, 0xe0, 0x5b, 0xe2, 0x39, 0x50, 0xd9, 0x8a,
|
|
0x6a, 0xb3, 0xc5, 0x2f, 0xdf, 0x74, 0xd5, 0x85,
|
|
0x8f, 0xd1, 0xba, 0x64, 0x54, 0x7b, 0xdb, 0x1e,
|
|
0xc5, 0xea, 0x24, 0xc0, 0xfa, 0x0c, 0x90, 0x15,
|
|
0x09, 0x20, 0x92, 0x42, 0x32, 0x36, 0x45, 0x45,
|
|
0x7d, 0x20, 0x76, 0x6b, 0xcf, 0xa2, 0x15, 0xc8,
|
|
0x2f, 0x9f, 0xbc, 0x88, 0x3f, 0x80, 0xd1, 0x2c,
|
|
0xb7, 0x16, 0xd1, 0x80, 0x9e, 0xe1, 0xc9, 0xb3,
|
|
0x88, 0x1b, 0x21, 0x45, 0xef, 0xa1, 0x7f, 0xce,
|
|
0xc8, 0x92, 0x35, 0x55, 0x2a, 0xd9, 0x1d, 0x8e,
|
|
0x12, 0x38, 0xac, 0x01, 0x4e, 0x38, 0x18, 0x76,
|
|
0x9c, 0xf2, 0xb6, 0xd4, 0x13, 0xb6, 0x2c, 0x77,
|
|
0xc0, 0xe7, 0xe6, 0x0c, 0x47, 0x44, 0x95, 0xbe };
|
|
|
|
static const unsigned char entropy_source_nopr[] =
|
|
{ 0x4c, 0xfb, 0x21, 0x86, 0x73, 0x34, 0x6d, 0x9d,
|
|
0x50, 0xc9, 0x22, 0xe4, 0x9b, 0x0d, 0xfc, 0xd0,
|
|
0x90, 0xad, 0xf0, 0x4f, 0x5c, 0x3b, 0xa4, 0x73,
|
|
0x27, 0xdf, 0xcd, 0x6f, 0xa6, 0x3a, 0x78, 0x5c,
|
|
0x01, 0x69, 0x62, 0xa7, 0xfd, 0x27, 0x87, 0xa2,
|
|
0x4b, 0xf6, 0xbe, 0x47, 0xef, 0x37, 0x83, 0xf1,
|
|
0xb7, 0xec, 0x46, 0x07, 0x23, 0x63, 0x83, 0x4a,
|
|
0x1b, 0x01, 0x33, 0xf2, 0xc2, 0x38, 0x91, 0xdb,
|
|
0x4f, 0x11, 0xa6, 0x86, 0x51, 0xf2, 0x3e, 0x3a,
|
|
0x8b, 0x1f, 0xdc, 0x03, 0xb1, 0x92, 0xc7, 0xe7 };
|
|
|
|
static const unsigned char pers_pr[] =
|
|
{ 0x5a, 0x70, 0x95, 0xe9, 0x81, 0x40, 0x52, 0x33,
|
|
0x91, 0x53, 0x7e, 0x75, 0xd6, 0x19, 0x9d, 0x1e,
|
|
0xad, 0x0d, 0xc6, 0xa7, 0xde, 0x6c, 0x1f, 0xe0,
|
|
0xea, 0x18, 0x33, 0xa8, 0x7e, 0x06, 0x20, 0xe9 };
|
|
|
|
static const unsigned char pers_nopr[] =
|
|
{ 0x88, 0xee, 0xb8, 0xe0, 0xe8, 0x3b, 0xf3, 0x29,
|
|
0x4b, 0xda, 0xcd, 0x60, 0x99, 0xeb, 0xe4, 0xbf,
|
|
0x55, 0xec, 0xd9, 0x11, 0x3f, 0x71, 0xe5, 0xeb,
|
|
0xcb, 0x45, 0x75, 0xf3, 0xd6, 0xa6, 0x8a, 0x6b };
|
|
|
|
static const unsigned char result_pr[] =
|
|
{ 0xce, 0x2f, 0xdb, 0xb6, 0xd9, 0xb7, 0x39, 0x85,
|
|
0x04, 0xc5, 0xc0, 0x42, 0xc2, 0x31, 0xc6, 0x1d,
|
|
0x9b, 0x5a, 0x59, 0xf8, 0x7e, 0x0d, 0xcc, 0x62,
|
|
0x7b, 0x65, 0x11, 0x55, 0x10, 0xeb, 0x9e, 0x3d,
|
|
0xa4, 0xfb, 0x1c, 0x6a, 0x18, 0xc0, 0x74, 0xdb,
|
|
0xdd, 0xe7, 0x02, 0x23, 0x63, 0x21, 0xd0, 0x39,
|
|
0xf9, 0xa7, 0xc4, 0x52, 0x84, 0x3b, 0x49, 0x40,
|
|
0x72, 0x2b, 0xb0, 0x6c, 0x9c, 0xdb, 0xc3, 0x43 };
|
|
|
|
static const unsigned char result_nopr[] =
|
|
{ 0xa5, 0x51, 0x80, 0xa1, 0x90, 0xbe, 0xf3, 0xad,
|
|
0xaf, 0x28, 0xf6, 0xb7, 0x95, 0xe9, 0xf1, 0xf3,
|
|
0xd6, 0xdf, 0xa1, 0xb2, 0x7d, 0xd0, 0x46, 0x7b,
|
|
0x0c, 0x75, 0xf5, 0xfa, 0x93, 0x1e, 0x97, 0x14,
|
|
0x75, 0xb2, 0x7c, 0xae, 0x03, 0xa2, 0x96, 0x54,
|
|
0xe2, 0xf4, 0x09, 0x66, 0xea, 0x33, 0x64, 0x30,
|
|
0x40, 0xd1, 0x40, 0x0f, 0xe6, 0x77, 0x87, 0x3a,
|
|
0xf8, 0x09, 0x7c, 0x1f, 0xe9, 0xf0, 0x02, 0x98 };
|
|
#endif /* MBEDTLS_CTR_DRBG_USE_128_BIT_KEY */
|
|
|
|
static size_t 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 ) \
|
|
mbedtls_printf( "failed\n" ); \
|
|
return( 1 ); \
|
|
}
|
|
|
|
#define SELF_TEST_OUTPUT_DISCARD_LENGTH 64
|
|
|
|
/*
|
|
* Checkup routine
|
|
*/
|
|
int mbedtls_ctr_drbg_self_test( int verbose )
|
|
{
|
|
mbedtls_ctr_drbg_context ctx;
|
|
unsigned char buf[ sizeof( result_pr ) ];
|
|
|
|
mbedtls_ctr_drbg_init( &ctx );
|
|
|
|
/*
|
|
* Based on a NIST CTR_DRBG test vector (PR = True)
|
|
*/
|
|
if( verbose != 0 )
|
|
mbedtls_printf( " CTR_DRBG (PR = TRUE) : " );
|
|
|
|
test_offset = 0;
|
|
mbedtls_ctr_drbg_set_entropy_len( &ctx, MBEDTLS_CTR_DRBG_KEYSIZE );
|
|
mbedtls_ctr_drbg_set_nonce_len( &ctx, MBEDTLS_CTR_DRBG_KEYSIZE / 2 );
|
|
CHK( mbedtls_ctr_drbg_seed( &ctx,
|
|
ctr_drbg_self_test_entropy,
|
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(void *) entropy_source_pr,
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pers_pr, MBEDTLS_CTR_DRBG_KEYSIZE ) );
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mbedtls_ctr_drbg_set_prediction_resistance( &ctx, MBEDTLS_CTR_DRBG_PR_ON );
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CHK( mbedtls_ctr_drbg_random( &ctx, buf, SELF_TEST_OUTPUT_DISCARD_LENGTH ) );
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CHK( mbedtls_ctr_drbg_random( &ctx, buf, sizeof( result_pr ) ) );
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CHK( memcmp( buf, result_pr, sizeof( result_pr ) ) );
|
|
|
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mbedtls_ctr_drbg_free( &ctx );
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n" );
|
|
|
|
/*
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|
* Based on a NIST CTR_DRBG test vector (PR = FALSE)
|
|
*/
|
|
if( verbose != 0 )
|
|
mbedtls_printf( " CTR_DRBG (PR = FALSE): " );
|
|
|
|
mbedtls_ctr_drbg_init( &ctx );
|
|
|
|
test_offset = 0;
|
|
mbedtls_ctr_drbg_set_entropy_len( &ctx, MBEDTLS_CTR_DRBG_KEYSIZE);
|
|
mbedtls_ctr_drbg_set_nonce_len( &ctx, MBEDTLS_CTR_DRBG_KEYSIZE / 2 );
|
|
CHK( mbedtls_ctr_drbg_seed( &ctx,
|
|
ctr_drbg_self_test_entropy,
|
|
(void *) entropy_source_nopr,
|
|
pers_nopr, MBEDTLS_CTR_DRBG_KEYSIZE ) );
|
|
CHK( mbedtls_ctr_drbg_reseed( &ctx, NULL, 0 ) );
|
|
CHK( mbedtls_ctr_drbg_random( &ctx, buf, SELF_TEST_OUTPUT_DISCARD_LENGTH ) );
|
|
CHK( mbedtls_ctr_drbg_random( &ctx, buf, sizeof( result_nopr ) ) );
|
|
CHK( memcmp( buf, result_nopr, sizeof( result_nopr ) ) );
|
|
|
|
mbedtls_ctr_drbg_free( &ctx );
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n" );
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "\n" );
|
|
|
|
return( 0 );
|
|
}
|
|
#endif /* MBEDTLS_SELF_TEST */
|
|
|
|
#endif /* MBEDTLS_CTR_DRBG_C */
|