0,0 → 1,542 |
/** |
* \file chachapoly.c |
* |
* \brief ChaCha20-Poly1305 AEAD construction based on RFC 7539. |
* |
* Copyright (C) 2006-2016, ARM Limited, All Rights Reserved |
* SPDX-License-Identifier: GPL-2.0 |
* |
* 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. |
* |
* 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_CHACHAPOLY_C) |
|
#include "mbedtls/chachapoly.h" |
#include "mbedtls/platform_util.h" |
|
#include <string.h> |
|
#if defined(MBEDTLS_SELF_TEST) |
#if defined(MBEDTLS_PLATFORM_C) |
#include "mbedtls/platform.h" |
#else |
#include <stdio.h> |
#define mbedtls_printf printf |
#endif /* MBEDTLS_PLATFORM_C */ |
#endif /* MBEDTLS_SELF_TEST */ |
|
#if !defined(MBEDTLS_CHACHAPOLY_ALT) |
|
/* Parameter validation macros */ |
#define CHACHAPOLY_VALIDATE_RET( cond ) \ |
MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA ) |
#define CHACHAPOLY_VALIDATE( cond ) \ |
MBEDTLS_INTERNAL_VALIDATE( cond ) |
|
#define CHACHAPOLY_STATE_INIT ( 0 ) |
#define CHACHAPOLY_STATE_AAD ( 1 ) |
#define CHACHAPOLY_STATE_CIPHERTEXT ( 2 ) /* Encrypting or decrypting */ |
#define CHACHAPOLY_STATE_FINISHED ( 3 ) |
|
/** |
* \brief Adds nul bytes to pad the AAD for Poly1305. |
* |
* \param ctx The ChaCha20-Poly1305 context. |
*/ |
static int chachapoly_pad_aad( mbedtls_chachapoly_context *ctx ) |
{ |
uint32_t partial_block_len = (uint32_t) ( ctx->aad_len % 16U ); |
unsigned char zeroes[15]; |
|
if( partial_block_len == 0U ) |
return( 0 ); |
|
memset( zeroes, 0, sizeof( zeroes ) ); |
|
return( mbedtls_poly1305_update( &ctx->poly1305_ctx, |
zeroes, |
16U - partial_block_len ) ); |
} |
|
/** |
* \brief Adds nul bytes to pad the ciphertext for Poly1305. |
* |
* \param ctx The ChaCha20-Poly1305 context. |
*/ |
static int chachapoly_pad_ciphertext( mbedtls_chachapoly_context *ctx ) |
{ |
uint32_t partial_block_len = (uint32_t) ( ctx->ciphertext_len % 16U ); |
unsigned char zeroes[15]; |
|
if( partial_block_len == 0U ) |
return( 0 ); |
|
memset( zeroes, 0, sizeof( zeroes ) ); |
return( mbedtls_poly1305_update( &ctx->poly1305_ctx, |
zeroes, |
16U - partial_block_len ) ); |
} |
|
void mbedtls_chachapoly_init( mbedtls_chachapoly_context *ctx ) |
{ |
CHACHAPOLY_VALIDATE( ctx != NULL ); |
|
mbedtls_chacha20_init( &ctx->chacha20_ctx ); |
mbedtls_poly1305_init( &ctx->poly1305_ctx ); |
ctx->aad_len = 0U; |
ctx->ciphertext_len = 0U; |
ctx->state = CHACHAPOLY_STATE_INIT; |
ctx->mode = MBEDTLS_CHACHAPOLY_ENCRYPT; |
} |
|
void mbedtls_chachapoly_free( mbedtls_chachapoly_context *ctx ) |
{ |
if( ctx == NULL ) |
return; |
|
mbedtls_chacha20_free( &ctx->chacha20_ctx ); |
mbedtls_poly1305_free( &ctx->poly1305_ctx ); |
ctx->aad_len = 0U; |
ctx->ciphertext_len = 0U; |
ctx->state = CHACHAPOLY_STATE_INIT; |
ctx->mode = MBEDTLS_CHACHAPOLY_ENCRYPT; |
} |
|
int mbedtls_chachapoly_setkey( mbedtls_chachapoly_context *ctx, |
const unsigned char key[32] ) |
{ |
int ret; |
CHACHAPOLY_VALIDATE_RET( ctx != NULL ); |
CHACHAPOLY_VALIDATE_RET( key != NULL ); |
|
ret = mbedtls_chacha20_setkey( &ctx->chacha20_ctx, key ); |
|
return( ret ); |
} |
|
int mbedtls_chachapoly_starts( mbedtls_chachapoly_context *ctx, |
const unsigned char nonce[12], |
mbedtls_chachapoly_mode_t mode ) |
{ |
int ret; |
unsigned char poly1305_key[64]; |
CHACHAPOLY_VALIDATE_RET( ctx != NULL ); |
CHACHAPOLY_VALIDATE_RET( nonce != NULL ); |
|
/* Set counter = 0, will be update to 1 when generating Poly1305 key */ |
ret = mbedtls_chacha20_starts( &ctx->chacha20_ctx, nonce, 0U ); |
if( ret != 0 ) |
goto cleanup; |
|
/* Generate the Poly1305 key by getting the ChaCha20 keystream output with |
* counter = 0. This is the same as encrypting a buffer of zeroes. |
* Only the first 256-bits (32 bytes) of the key is used for Poly1305. |
* The other 256 bits are discarded. |
*/ |
memset( poly1305_key, 0, sizeof( poly1305_key ) ); |
ret = mbedtls_chacha20_update( &ctx->chacha20_ctx, sizeof( poly1305_key ), |
poly1305_key, poly1305_key ); |
if( ret != 0 ) |
goto cleanup; |
|
ret = mbedtls_poly1305_starts( &ctx->poly1305_ctx, poly1305_key ); |
|
if( ret == 0 ) |
{ |
ctx->aad_len = 0U; |
ctx->ciphertext_len = 0U; |
ctx->state = CHACHAPOLY_STATE_AAD; |
ctx->mode = mode; |
} |
|
cleanup: |
mbedtls_platform_zeroize( poly1305_key, 64U ); |
return( ret ); |
} |
|
int mbedtls_chachapoly_update_aad( mbedtls_chachapoly_context *ctx, |
const unsigned char *aad, |
size_t aad_len ) |
{ |
CHACHAPOLY_VALIDATE_RET( ctx != NULL ); |
CHACHAPOLY_VALIDATE_RET( aad_len == 0 || aad != NULL ); |
|
if( ctx->state != CHACHAPOLY_STATE_AAD ) |
return( MBEDTLS_ERR_CHACHAPOLY_BAD_STATE ); |
|
ctx->aad_len += aad_len; |
|
return( mbedtls_poly1305_update( &ctx->poly1305_ctx, aad, aad_len ) ); |
} |
|
int mbedtls_chachapoly_update( mbedtls_chachapoly_context *ctx, |
size_t len, |
const unsigned char *input, |
unsigned char *output ) |
{ |
int ret; |
CHACHAPOLY_VALIDATE_RET( ctx != NULL ); |
CHACHAPOLY_VALIDATE_RET( len == 0 || input != NULL ); |
CHACHAPOLY_VALIDATE_RET( len == 0 || output != NULL ); |
|
if( ( ctx->state != CHACHAPOLY_STATE_AAD ) && |
( ctx->state != CHACHAPOLY_STATE_CIPHERTEXT ) ) |
{ |
return( MBEDTLS_ERR_CHACHAPOLY_BAD_STATE ); |
} |
|
if( ctx->state == CHACHAPOLY_STATE_AAD ) |
{ |
ctx->state = CHACHAPOLY_STATE_CIPHERTEXT; |
|
ret = chachapoly_pad_aad( ctx ); |
if( ret != 0 ) |
return( ret ); |
} |
|
ctx->ciphertext_len += len; |
|
if( ctx->mode == MBEDTLS_CHACHAPOLY_ENCRYPT ) |
{ |
ret = mbedtls_chacha20_update( &ctx->chacha20_ctx, len, input, output ); |
if( ret != 0 ) |
return( ret ); |
|
ret = mbedtls_poly1305_update( &ctx->poly1305_ctx, output, len ); |
if( ret != 0 ) |
return( ret ); |
} |
else /* DECRYPT */ |
{ |
ret = mbedtls_poly1305_update( &ctx->poly1305_ctx, input, len ); |
if( ret != 0 ) |
return( ret ); |
|
ret = mbedtls_chacha20_update( &ctx->chacha20_ctx, len, input, output ); |
if( ret != 0 ) |
return( ret ); |
} |
|
return( 0 ); |
} |
|
int mbedtls_chachapoly_finish( mbedtls_chachapoly_context *ctx, |
unsigned char mac[16] ) |
{ |
int ret; |
unsigned char len_block[16]; |
CHACHAPOLY_VALIDATE_RET( ctx != NULL ); |
CHACHAPOLY_VALIDATE_RET( mac != NULL ); |
|
if( ctx->state == CHACHAPOLY_STATE_INIT ) |
{ |
return( MBEDTLS_ERR_CHACHAPOLY_BAD_STATE ); |
} |
|
if( ctx->state == CHACHAPOLY_STATE_AAD ) |
{ |
ret = chachapoly_pad_aad( ctx ); |
if( ret != 0 ) |
return( ret ); |
} |
else if( ctx->state == CHACHAPOLY_STATE_CIPHERTEXT ) |
{ |
ret = chachapoly_pad_ciphertext( ctx ); |
if( ret != 0 ) |
return( ret ); |
} |
|
ctx->state = CHACHAPOLY_STATE_FINISHED; |
|
/* The lengths of the AAD and ciphertext are processed by |
* Poly1305 as the final 128-bit block, encoded as little-endian integers. |
*/ |
len_block[ 0] = (unsigned char)( ctx->aad_len ); |
len_block[ 1] = (unsigned char)( ctx->aad_len >> 8 ); |
len_block[ 2] = (unsigned char)( ctx->aad_len >> 16 ); |
len_block[ 3] = (unsigned char)( ctx->aad_len >> 24 ); |
len_block[ 4] = (unsigned char)( ctx->aad_len >> 32 ); |
len_block[ 5] = (unsigned char)( ctx->aad_len >> 40 ); |
len_block[ 6] = (unsigned char)( ctx->aad_len >> 48 ); |
len_block[ 7] = (unsigned char)( ctx->aad_len >> 56 ); |
len_block[ 8] = (unsigned char)( ctx->ciphertext_len ); |
len_block[ 9] = (unsigned char)( ctx->ciphertext_len >> 8 ); |
len_block[10] = (unsigned char)( ctx->ciphertext_len >> 16 ); |
len_block[11] = (unsigned char)( ctx->ciphertext_len >> 24 ); |
len_block[12] = (unsigned char)( ctx->ciphertext_len >> 32 ); |
len_block[13] = (unsigned char)( ctx->ciphertext_len >> 40 ); |
len_block[14] = (unsigned char)( ctx->ciphertext_len >> 48 ); |
len_block[15] = (unsigned char)( ctx->ciphertext_len >> 56 ); |
|
ret = mbedtls_poly1305_update( &ctx->poly1305_ctx, len_block, 16U ); |
if( ret != 0 ) |
return( ret ); |
|
ret = mbedtls_poly1305_finish( &ctx->poly1305_ctx, mac ); |
|
return( ret ); |
} |
|
static int chachapoly_crypt_and_tag( mbedtls_chachapoly_context *ctx, |
mbedtls_chachapoly_mode_t mode, |
size_t length, |
const unsigned char nonce[12], |
const unsigned char *aad, |
size_t aad_len, |
const unsigned char *input, |
unsigned char *output, |
unsigned char tag[16] ) |
{ |
int ret; |
|
ret = mbedtls_chachapoly_starts( ctx, nonce, mode ); |
if( ret != 0 ) |
goto cleanup; |
|
ret = mbedtls_chachapoly_update_aad( ctx, aad, aad_len ); |
if( ret != 0 ) |
goto cleanup; |
|
ret = mbedtls_chachapoly_update( ctx, length, input, output ); |
if( ret != 0 ) |
goto cleanup; |
|
ret = mbedtls_chachapoly_finish( ctx, tag ); |
|
cleanup: |
return( ret ); |
} |
|
int mbedtls_chachapoly_encrypt_and_tag( mbedtls_chachapoly_context *ctx, |
size_t length, |
const unsigned char nonce[12], |
const unsigned char *aad, |
size_t aad_len, |
const unsigned char *input, |
unsigned char *output, |
unsigned char tag[16] ) |
{ |
CHACHAPOLY_VALIDATE_RET( ctx != NULL ); |
CHACHAPOLY_VALIDATE_RET( nonce != NULL ); |
CHACHAPOLY_VALIDATE_RET( tag != NULL ); |
CHACHAPOLY_VALIDATE_RET( aad_len == 0 || aad != NULL ); |
CHACHAPOLY_VALIDATE_RET( length == 0 || input != NULL ); |
CHACHAPOLY_VALIDATE_RET( length == 0 || output != NULL ); |
|
return( chachapoly_crypt_and_tag( ctx, MBEDTLS_CHACHAPOLY_ENCRYPT, |
length, nonce, aad, aad_len, |
input, output, tag ) ); |
} |
|
int mbedtls_chachapoly_auth_decrypt( mbedtls_chachapoly_context *ctx, |
size_t length, |
const unsigned char nonce[12], |
const unsigned char *aad, |
size_t aad_len, |
const unsigned char tag[16], |
const unsigned char *input, |
unsigned char *output ) |
{ |
int ret; |
unsigned char check_tag[16]; |
size_t i; |
int diff; |
CHACHAPOLY_VALIDATE_RET( ctx != NULL ); |
CHACHAPOLY_VALIDATE_RET( nonce != NULL ); |
CHACHAPOLY_VALIDATE_RET( tag != NULL ); |
CHACHAPOLY_VALIDATE_RET( aad_len == 0 || aad != NULL ); |
CHACHAPOLY_VALIDATE_RET( length == 0 || input != NULL ); |
CHACHAPOLY_VALIDATE_RET( length == 0 || output != NULL ); |
|
if( ( ret = chachapoly_crypt_and_tag( ctx, |
MBEDTLS_CHACHAPOLY_DECRYPT, length, nonce, |
aad, aad_len, input, output, check_tag ) ) != 0 ) |
{ |
return( ret ); |
} |
|
/* Check tag in "constant-time" */ |
for( diff = 0, i = 0; i < sizeof( check_tag ); i++ ) |
diff |= tag[i] ^ check_tag[i]; |
|
if( diff != 0 ) |
{ |
mbedtls_platform_zeroize( output, length ); |
return( MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED ); |
} |
|
return( 0 ); |
} |
|
#endif /* MBEDTLS_CHACHAPOLY_ALT */ |
|
#if defined(MBEDTLS_SELF_TEST) |
|
static const unsigned char test_key[1][32] = |
{ |
{ |
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, |
0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, |
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, |
0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f |
} |
}; |
|
static const unsigned char test_nonce[1][12] = |
{ |
{ |
0x07, 0x00, 0x00, 0x00, /* 32-bit common part */ |
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 /* 64-bit IV */ |
} |
}; |
|
static const unsigned char test_aad[1][12] = |
{ |
{ |
0x50, 0x51, 0x52, 0x53, 0xc0, 0xc1, 0xc2, 0xc3, |
0xc4, 0xc5, 0xc6, 0xc7 |
} |
}; |
|
static const size_t test_aad_len[1] = |
{ |
12U |
}; |
|
static const unsigned char test_input[1][114] = |
{ |
{ |
0x4c, 0x61, 0x64, 0x69, 0x65, 0x73, 0x20, 0x61, |
0x6e, 0x64, 0x20, 0x47, 0x65, 0x6e, 0x74, 0x6c, |
0x65, 0x6d, 0x65, 0x6e, 0x20, 0x6f, 0x66, 0x20, |
0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x61, 0x73, |
0x73, 0x20, 0x6f, 0x66, 0x20, 0x27, 0x39, 0x39, |
0x3a, 0x20, 0x49, 0x66, 0x20, 0x49, 0x20, 0x63, |
0x6f, 0x75, 0x6c, 0x64, 0x20, 0x6f, 0x66, 0x66, |
0x65, 0x72, 0x20, 0x79, 0x6f, 0x75, 0x20, 0x6f, |
0x6e, 0x6c, 0x79, 0x20, 0x6f, 0x6e, 0x65, 0x20, |
0x74, 0x69, 0x70, 0x20, 0x66, 0x6f, 0x72, 0x20, |
0x74, 0x68, 0x65, 0x20, 0x66, 0x75, 0x74, 0x75, |
0x72, 0x65, 0x2c, 0x20, 0x73, 0x75, 0x6e, 0x73, |
0x63, 0x72, 0x65, 0x65, 0x6e, 0x20, 0x77, 0x6f, |
0x75, 0x6c, 0x64, 0x20, 0x62, 0x65, 0x20, 0x69, |
0x74, 0x2e |
} |
}; |
|
static const unsigned char test_output[1][114] = |
{ |
{ |
0xd3, 0x1a, 0x8d, 0x34, 0x64, 0x8e, 0x60, 0xdb, |
0x7b, 0x86, 0xaf, 0xbc, 0x53, 0xef, 0x7e, 0xc2, |
0xa4, 0xad, 0xed, 0x51, 0x29, 0x6e, 0x08, 0xfe, |
0xa9, 0xe2, 0xb5, 0xa7, 0x36, 0xee, 0x62, 0xd6, |
0x3d, 0xbe, 0xa4, 0x5e, 0x8c, 0xa9, 0x67, 0x12, |
0x82, 0xfa, 0xfb, 0x69, 0xda, 0x92, 0x72, 0x8b, |
0x1a, 0x71, 0xde, 0x0a, 0x9e, 0x06, 0x0b, 0x29, |
0x05, 0xd6, 0xa5, 0xb6, 0x7e, 0xcd, 0x3b, 0x36, |
0x92, 0xdd, 0xbd, 0x7f, 0x2d, 0x77, 0x8b, 0x8c, |
0x98, 0x03, 0xae, 0xe3, 0x28, 0x09, 0x1b, 0x58, |
0xfa, 0xb3, 0x24, 0xe4, 0xfa, 0xd6, 0x75, 0x94, |
0x55, 0x85, 0x80, 0x8b, 0x48, 0x31, 0xd7, 0xbc, |
0x3f, 0xf4, 0xde, 0xf0, 0x8e, 0x4b, 0x7a, 0x9d, |
0xe5, 0x76, 0xd2, 0x65, 0x86, 0xce, 0xc6, 0x4b, |
0x61, 0x16 |
} |
}; |
|
static const size_t test_input_len[1] = |
{ |
114U |
}; |
|
static const unsigned char test_mac[1][16] = |
{ |
{ |
0x1a, 0xe1, 0x0b, 0x59, 0x4f, 0x09, 0xe2, 0x6a, |
0x7e, 0x90, 0x2e, 0xcb, 0xd0, 0x60, 0x06, 0x91 |
} |
}; |
|
#define ASSERT( cond, args ) \ |
do \ |
{ \ |
if( ! ( cond ) ) \ |
{ \ |
if( verbose != 0 ) \ |
mbedtls_printf args; \ |
\ |
return( -1 ); \ |
} \ |
} \ |
while( 0 ) |
|
int mbedtls_chachapoly_self_test( int verbose ) |
{ |
mbedtls_chachapoly_context ctx; |
unsigned i; |
int ret; |
unsigned char output[200]; |
unsigned char mac[16]; |
|
for( i = 0U; i < 1U; i++ ) |
{ |
if( verbose != 0 ) |
mbedtls_printf( " ChaCha20-Poly1305 test %u ", i ); |
|
mbedtls_chachapoly_init( &ctx ); |
|
ret = mbedtls_chachapoly_setkey( &ctx, test_key[i] ); |
ASSERT( 0 == ret, ( "setkey() error code: %i\n", ret ) ); |
|
ret = mbedtls_chachapoly_encrypt_and_tag( &ctx, |
test_input_len[i], |
test_nonce[i], |
test_aad[i], |
test_aad_len[i], |
test_input[i], |
output, |
mac ); |
|
ASSERT( 0 == ret, ( "crypt_and_tag() error code: %i\n", ret ) ); |
|
ASSERT( 0 == memcmp( output, test_output[i], test_input_len[i] ), |
( "failure (wrong output)\n" ) ); |
|
ASSERT( 0 == memcmp( mac, test_mac[i], 16U ), |
( "failure (wrong MAC)\n" ) ); |
|
mbedtls_chachapoly_free( &ctx ); |
|
if( verbose != 0 ) |
mbedtls_printf( "passed\n" ); |
} |
|
if( verbose != 0 ) |
mbedtls_printf( "\n" ); |
|
return( 0 ); |
} |
|
#endif /* MBEDTLS_SELF_TEST */ |
|
#endif /* MBEDTLS_CHACHAPOLY_C */ |