868da0741c
This commit resolves a blocking in esp_aes_block function. Introduce: The problem was in the fact that AES is switched off at the moment when he should give out the processed data. But because of the disabled, the operation can not be completed successfully, there is an infinite hang. The reason for this behavior is that the registers for controlling the inclusion of AES, SHA, MPI have shared registers and they were not protected from sharing. Fix some related issue with shared using of AES SHA RSA accelerators. Closes: https://github.com/espressif/esp-idf/issues/2295#issuecomment-432898137
626 lines
18 KiB
C
626 lines
18 KiB
C
/**
|
|
* \brief AES block cipher, ESP32 hardware accelerated version
|
|
* Based on mbedTLS FIPS-197 compliant version.
|
|
*
|
|
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
|
|
* Additions Copyright (C) 2016-2017, Espressif Systems (Shanghai) PTE Ltd
|
|
* 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.
|
|
*
|
|
*/
|
|
/*
|
|
* The AES block cipher was designed by Vincent Rijmen and Joan Daemen.
|
|
*
|
|
* http://csrc.nist.gov/encryption/aes/rijndael/Rijndael.pdf
|
|
* http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf
|
|
*/
|
|
#include <string.h>
|
|
#include "mbedtls/aes.h"
|
|
#include "hwcrypto/aes.h"
|
|
#include "soc/dport_reg.h"
|
|
#include "soc/hwcrypto_reg.h"
|
|
#include <sys/lock.h>
|
|
|
|
#include <freertos/FreeRTOS.h>
|
|
|
|
#include "soc/cpu.h"
|
|
#include <stdio.h>
|
|
#include "driver/periph_ctrl.h"
|
|
|
|
|
|
/* AES uses a spinlock mux not a lock as the underlying block operation
|
|
only takes 208 cycles (to write key & compute block), +600 cycles
|
|
for DPORT protection but +3400 cycles again if you use a full sized lock.
|
|
|
|
For CBC, CFB, etc. this may mean that interrupts are disabled for a longer
|
|
period of time for bigger lengths. However at the moment this has to happen
|
|
anyway due to DPORT protection...
|
|
*/
|
|
static portMUX_TYPE aes_spinlock = portMUX_INITIALIZER_UNLOCKED;
|
|
|
|
void esp_aes_acquire_hardware( void )
|
|
{
|
|
portENTER_CRITICAL(&aes_spinlock);
|
|
|
|
/* Enable AES hardware */
|
|
periph_module_enable(PERIPH_AES_MODULE);
|
|
}
|
|
|
|
void esp_aes_release_hardware( void )
|
|
{
|
|
/* Disable AES hardware */
|
|
periph_module_disable(PERIPH_AES_MODULE);
|
|
|
|
portEXIT_CRITICAL(&aes_spinlock);
|
|
}
|
|
|
|
void esp_aes_init( esp_aes_context *ctx )
|
|
{
|
|
bzero( ctx, sizeof( esp_aes_context ) );
|
|
}
|
|
|
|
void esp_aes_free( esp_aes_context *ctx )
|
|
{
|
|
if ( ctx == NULL ) {
|
|
return;
|
|
}
|
|
|
|
bzero( ctx, sizeof( esp_aes_context ) );
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* AES key schedule (same for encryption or decryption, as hardware handles schedule)
|
|
*
|
|
*/
|
|
int esp_aes_setkey( esp_aes_context *ctx, const unsigned char *key,
|
|
unsigned int keybits )
|
|
{
|
|
if (keybits != 128 && keybits != 192 && keybits != 256) {
|
|
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
|
|
}
|
|
ctx->key_bytes = keybits / 8;
|
|
memcpy(ctx->key, key, ctx->key_bytes);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Helper function to copy key from esp_aes_context buffer
|
|
* to hardware key registers.
|
|
*
|
|
* Call only while holding esp_aes_acquire_hardware().
|
|
*/
|
|
static inline void esp_aes_setkey_hardware( esp_aes_context *ctx, int mode)
|
|
{
|
|
const uint32_t MODE_DECRYPT_BIT = 4;
|
|
unsigned mode_reg_base = (mode == ESP_AES_ENCRYPT) ? 0 : MODE_DECRYPT_BIT;
|
|
|
|
for (int i = 0; i < ctx->key_bytes/4; ++i) {
|
|
DPORT_REG_WRITE(AES_KEY_BASE + i * 4, *(((uint32_t *)ctx->key) + i));
|
|
}
|
|
|
|
DPORT_REG_WRITE(AES_MODE_REG, mode_reg_base + ((ctx->key_bytes / 8) - 2));
|
|
}
|
|
|
|
/* Run a single 16 byte block of AES, using the hardware engine.
|
|
*
|
|
* Call only while holding esp_aes_acquire_hardware().
|
|
*/
|
|
static inline void esp_aes_block(const void *input, void *output)
|
|
{
|
|
const uint32_t *input_words = (const uint32_t *)input;
|
|
uint32_t *output_words = (uint32_t *)output;
|
|
uint32_t *mem_block = (uint32_t *)AES_TEXT_BASE;
|
|
|
|
for(int i = 0; i < 4; i++) {
|
|
mem_block[i] = input_words[i];
|
|
}
|
|
|
|
DPORT_REG_WRITE(AES_START_REG, 1);
|
|
while (DPORT_REG_READ(AES_IDLE_REG) != 1) { }
|
|
esp_dport_access_read_buffer(output_words, (uint32_t)&mem_block[0], 4);
|
|
}
|
|
|
|
/*
|
|
* AES-ECB block encryption
|
|
*/
|
|
int esp_internal_aes_encrypt( esp_aes_context *ctx,
|
|
const unsigned char input[16],
|
|
unsigned char output[16] )
|
|
{
|
|
esp_aes_acquire_hardware();
|
|
esp_aes_setkey_hardware(ctx, ESP_AES_ENCRYPT);
|
|
esp_aes_block(input, output);
|
|
esp_aes_release_hardware();
|
|
return 0;
|
|
}
|
|
|
|
void esp_aes_encrypt( esp_aes_context *ctx,
|
|
const unsigned char input[16],
|
|
unsigned char output[16] )
|
|
{
|
|
esp_internal_aes_encrypt(ctx, input, output);
|
|
}
|
|
|
|
/*
|
|
* AES-ECB block decryption
|
|
*/
|
|
|
|
int esp_internal_aes_decrypt( esp_aes_context *ctx,
|
|
const unsigned char input[16],
|
|
unsigned char output[16] )
|
|
{
|
|
esp_aes_acquire_hardware();
|
|
esp_aes_setkey_hardware(ctx, ESP_AES_DECRYPT);
|
|
esp_aes_block(input, output);
|
|
esp_aes_release_hardware();
|
|
return 0;
|
|
}
|
|
|
|
void esp_aes_decrypt( esp_aes_context *ctx,
|
|
const unsigned char input[16],
|
|
unsigned char output[16] )
|
|
{
|
|
esp_internal_aes_decrypt(ctx, input, output);
|
|
}
|
|
|
|
|
|
/*
|
|
* AES-ECB block encryption/decryption
|
|
*/
|
|
int esp_aes_crypt_ecb( esp_aes_context *ctx,
|
|
int mode,
|
|
const unsigned char input[16],
|
|
unsigned char output[16] )
|
|
{
|
|
esp_aes_acquire_hardware();
|
|
esp_aes_setkey_hardware(ctx, mode);
|
|
esp_aes_block(input, output);
|
|
esp_aes_release_hardware();
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* AES-CBC buffer encryption/decryption
|
|
*/
|
|
int esp_aes_crypt_cbc( esp_aes_context *ctx,
|
|
int mode,
|
|
size_t length,
|
|
unsigned char iv[16],
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
int i;
|
|
uint32_t *output_words = (uint32_t *)output;
|
|
const uint32_t *input_words = (const uint32_t *)input;
|
|
uint32_t *iv_words = (uint32_t *)iv;
|
|
unsigned char temp[16];
|
|
|
|
if ( length % 16 ) {
|
|
return ( ERR_ESP_AES_INVALID_INPUT_LENGTH );
|
|
}
|
|
|
|
esp_aes_acquire_hardware();
|
|
|
|
esp_aes_setkey_hardware(ctx, mode);
|
|
|
|
if ( mode == ESP_AES_DECRYPT ) {
|
|
while ( length > 0 ) {
|
|
memcpy(temp, input_words, 16);
|
|
esp_aes_block(input_words, output_words);
|
|
|
|
for ( i = 0; i < 4; i++ ) {
|
|
output_words[i] = output_words[i] ^ iv_words[i];
|
|
}
|
|
|
|
memcpy( iv_words, temp, 16 );
|
|
|
|
input_words += 4;
|
|
output_words += 4;
|
|
length -= 16;
|
|
}
|
|
} else { // ESP_AES_ENCRYPT
|
|
while ( length > 0 ) {
|
|
|
|
for ( i = 0; i < 4; i++ ) {
|
|
output_words[i] = input_words[i] ^ iv_words[i];
|
|
}
|
|
|
|
esp_aes_block(output_words, output_words);
|
|
memcpy( iv_words, output_words, 16 );
|
|
|
|
input_words += 4;
|
|
output_words += 4;
|
|
length -= 16;
|
|
}
|
|
}
|
|
|
|
esp_aes_release_hardware();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* AES-CFB128 buffer encryption/decryption
|
|
*/
|
|
int esp_aes_crypt_cfb128( esp_aes_context *ctx,
|
|
int mode,
|
|
size_t length,
|
|
size_t *iv_off,
|
|
unsigned char iv[16],
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
int c;
|
|
size_t n = *iv_off;
|
|
|
|
esp_aes_acquire_hardware();
|
|
|
|
esp_aes_setkey_hardware(ctx, ESP_AES_ENCRYPT);
|
|
|
|
if ( mode == ESP_AES_DECRYPT ) {
|
|
while ( length-- ) {
|
|
if ( n == 0 ) {
|
|
esp_aes_block(iv, iv );
|
|
}
|
|
|
|
c = *input++;
|
|
*output++ = (unsigned char)( c ^ iv[n] );
|
|
iv[n] = (unsigned char) c;
|
|
|
|
n = ( n + 1 ) & 0x0F;
|
|
}
|
|
} else {
|
|
while ( length-- ) {
|
|
if ( n == 0 ) {
|
|
esp_aes_block(iv, iv );
|
|
}
|
|
|
|
iv[n] = *output++ = (unsigned char)( iv[n] ^ *input++ );
|
|
|
|
n = ( n + 1 ) & 0x0F;
|
|
}
|
|
}
|
|
|
|
*iv_off = n;
|
|
|
|
esp_aes_release_hardware();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* AES-CFB8 buffer encryption/decryption
|
|
*/
|
|
int esp_aes_crypt_cfb8( esp_aes_context *ctx,
|
|
int mode,
|
|
size_t length,
|
|
unsigned char iv[16],
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
unsigned char c;
|
|
unsigned char ov[17];
|
|
|
|
esp_aes_acquire_hardware();
|
|
|
|
esp_aes_setkey_hardware(ctx, ESP_AES_ENCRYPT);
|
|
|
|
while ( length-- ) {
|
|
memcpy( ov, iv, 16 );
|
|
esp_aes_block(iv, iv);
|
|
|
|
if ( mode == ESP_AES_DECRYPT ) {
|
|
ov[16] = *input;
|
|
}
|
|
|
|
c = *output++ = (unsigned char)( iv[0] ^ *input++ );
|
|
|
|
if ( mode == ESP_AES_ENCRYPT ) {
|
|
ov[16] = c;
|
|
}
|
|
|
|
memcpy( iv, ov + 1, 16 );
|
|
}
|
|
|
|
esp_aes_release_hardware();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* AES-CTR buffer encryption/decryption
|
|
*/
|
|
int esp_aes_crypt_ctr( esp_aes_context *ctx,
|
|
size_t length,
|
|
size_t *nc_off,
|
|
unsigned char nonce_counter[16],
|
|
unsigned char stream_block[16],
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
int c, i;
|
|
size_t n = *nc_off;
|
|
|
|
esp_aes_acquire_hardware();
|
|
|
|
esp_aes_setkey_hardware(ctx, ESP_AES_ENCRYPT);
|
|
|
|
while ( length-- ) {
|
|
if ( n == 0 ) {
|
|
esp_aes_block(nonce_counter, stream_block);
|
|
|
|
for ( i = 16; i > 0; i-- )
|
|
if ( ++nonce_counter[i - 1] != 0 ) {
|
|
break;
|
|
}
|
|
}
|
|
c = *input++;
|
|
*output++ = (unsigned char)( c ^ stream_block[n] );
|
|
|
|
n = ( n + 1 ) & 0x0F;
|
|
}
|
|
|
|
*nc_off = n;
|
|
|
|
esp_aes_release_hardware();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Below XTS implementation is copied aes.c of mbedtls library.
|
|
* When MBEDTLS_AES_ALT is defined mbedtls expects alternate
|
|
* definition of XTS functions to be available. Even if this
|
|
* could have been avoided, it is done for consistency reason.
|
|
*/
|
|
|
|
void esp_aes_xts_init( esp_aes_xts_context *ctx )
|
|
{
|
|
esp_aes_init( &ctx->crypt );
|
|
esp_aes_init( &ctx->tweak );
|
|
}
|
|
|
|
void esp_aes_xts_free( esp_aes_xts_context *ctx )
|
|
{
|
|
esp_aes_free( &ctx->crypt );
|
|
esp_aes_free( &ctx->tweak );
|
|
}
|
|
|
|
static int esp_aes_xts_decode_keys( const unsigned char *key,
|
|
unsigned int keybits,
|
|
const unsigned char **key1,
|
|
unsigned int *key1bits,
|
|
const unsigned char **key2,
|
|
unsigned int *key2bits )
|
|
{
|
|
const unsigned int half_keybits = keybits / 2;
|
|
const unsigned int half_keybytes = half_keybits / 8;
|
|
|
|
switch( keybits )
|
|
{
|
|
case 256: break;
|
|
case 512: break;
|
|
default : return( MBEDTLS_ERR_AES_INVALID_KEY_LENGTH );
|
|
}
|
|
|
|
*key1bits = half_keybits;
|
|
*key2bits = half_keybits;
|
|
*key1 = &key[0];
|
|
*key2 = &key[half_keybytes];
|
|
|
|
return 0;
|
|
}
|
|
|
|
int esp_aes_xts_setkey_enc( mbedtls_aes_xts_context *ctx,
|
|
const unsigned char *key,
|
|
unsigned int keybits)
|
|
{
|
|
int ret;
|
|
const unsigned char *key1, *key2;
|
|
unsigned int key1bits, key2bits;
|
|
|
|
ret = esp_aes_xts_decode_keys( key, keybits, &key1, &key1bits,
|
|
&key2, &key2bits );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
/* Set the tweak key. Always set tweak key for the encryption mode. */
|
|
ret = esp_aes_setkey( &ctx->tweak, key2, key2bits );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
/* Set crypt key for encryption. */
|
|
return esp_aes_setkey( &ctx->crypt, key1, key1bits );
|
|
}
|
|
|
|
int esp_aes_xts_setkey_dec( mbedtls_aes_xts_context *ctx,
|
|
const unsigned char *key,
|
|
unsigned int keybits)
|
|
{
|
|
int ret;
|
|
const unsigned char *key1, *key2;
|
|
unsigned int key1bits, key2bits;
|
|
|
|
ret = esp_aes_xts_decode_keys( key, keybits, &key1, &key1bits,
|
|
&key2, &key2bits );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
/* Set the tweak key. Always set tweak key for encryption. */
|
|
ret = esp_aes_setkey( &ctx->tweak, key2, key2bits );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
/* Set crypt key for decryption. */
|
|
return esp_aes_setkey( &ctx->crypt, key1, key1bits );
|
|
}
|
|
|
|
/* Endianess with 64 bits values */
|
|
#ifndef GET_UINT64_LE
|
|
#define GET_UINT64_LE(n,b,i) \
|
|
{ \
|
|
(n) = ( (uint64_t) (b)[(i) + 7] << 56 ) \
|
|
| ( (uint64_t) (b)[(i) + 6] << 48 ) \
|
|
| ( (uint64_t) (b)[(i) + 5] << 40 ) \
|
|
| ( (uint64_t) (b)[(i) + 4] << 32 ) \
|
|
| ( (uint64_t) (b)[(i) + 3] << 24 ) \
|
|
| ( (uint64_t) (b)[(i) + 2] << 16 ) \
|
|
| ( (uint64_t) (b)[(i) + 1] << 8 ) \
|
|
| ( (uint64_t) (b)[(i) ] ); \
|
|
}
|
|
#endif
|
|
|
|
#ifndef PUT_UINT64_LE
|
|
#define PUT_UINT64_LE(n,b,i) \
|
|
{ \
|
|
(b)[(i) + 7] = (unsigned char) ( (n) >> 56 ); \
|
|
(b)[(i) + 6] = (unsigned char) ( (n) >> 48 ); \
|
|
(b)[(i) + 5] = (unsigned char) ( (n) >> 40 ); \
|
|
(b)[(i) + 4] = (unsigned char) ( (n) >> 32 ); \
|
|
(b)[(i) + 3] = (unsigned char) ( (n) >> 24 ); \
|
|
(b)[(i) + 2] = (unsigned char) ( (n) >> 16 ); \
|
|
(b)[(i) + 1] = (unsigned char) ( (n) >> 8 ); \
|
|
(b)[(i) ] = (unsigned char) ( (n) ); \
|
|
}
|
|
#endif
|
|
|
|
typedef unsigned char esp_be128[16];
|
|
|
|
/*
|
|
* GF(2^128) multiplication function
|
|
*
|
|
* This function multiplies a field element by x in the polynomial field
|
|
* representation. It uses 64-bit word operations to gain speed but compensates
|
|
* for machine endianess and hence works correctly on both big and little
|
|
* endian machines.
|
|
*/
|
|
static void esp_gf128mul_x_ble( unsigned char r[16],
|
|
const unsigned char x[16] )
|
|
{
|
|
uint64_t a, b, ra, rb;
|
|
|
|
GET_UINT64_LE( a, x, 0 );
|
|
GET_UINT64_LE( b, x, 8 );
|
|
|
|
ra = ( a << 1 ) ^ 0x0087 >> ( 8 - ( ( b >> 63 ) << 3 ) );
|
|
rb = ( a >> 63 ) | ( b << 1 );
|
|
|
|
PUT_UINT64_LE( ra, r, 0 );
|
|
PUT_UINT64_LE( rb, r, 8 );
|
|
}
|
|
|
|
/*
|
|
* AES-XTS buffer encryption/decryption
|
|
*/
|
|
int esp_aes_crypt_xts( mbedtls_aes_xts_context *ctx,
|
|
int mode,
|
|
size_t length,
|
|
const unsigned char data_unit[16],
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
int ret;
|
|
size_t blocks = length / 16;
|
|
size_t leftover = length % 16;
|
|
unsigned char tweak[16];
|
|
unsigned char prev_tweak[16];
|
|
unsigned char tmp[16];
|
|
|
|
/* Sectors must be at least 16 bytes. */
|
|
if( length < 16 )
|
|
return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
|
|
|
|
/* NIST SP 80-38E disallows data units larger than 2**20 blocks. */
|
|
if( length > ( 1 << 20 ) * 16 )
|
|
return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
|
|
|
|
/* Compute the tweak. */
|
|
ret = esp_aes_crypt_ecb( &ctx->tweak, MBEDTLS_AES_ENCRYPT,
|
|
data_unit, tweak );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
while( blocks-- )
|
|
{
|
|
size_t i;
|
|
|
|
if( leftover && ( mode == MBEDTLS_AES_DECRYPT ) && blocks == 0 )
|
|
{
|
|
/* We are on the last block in a decrypt operation that has
|
|
* leftover bytes, so we need to use the next tweak for this block,
|
|
* and this tweak for the lefover bytes. Save the current tweak for
|
|
* the leftovers and then update the current tweak for use on this,
|
|
* the last full block. */
|
|
memcpy( prev_tweak, tweak, sizeof( tweak ) );
|
|
esp_gf128mul_x_ble( tweak, tweak );
|
|
}
|
|
|
|
for( i = 0; i < 16; i++ )
|
|
tmp[i] = input[i] ^ tweak[i];
|
|
|
|
ret = esp_aes_crypt_ecb( &ctx->crypt, mode, tmp, tmp );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
for( i = 0; i < 16; i++ )
|
|
output[i] = tmp[i] ^ tweak[i];
|
|
|
|
/* Update the tweak for the next block. */
|
|
esp_gf128mul_x_ble( tweak, tweak );
|
|
|
|
output += 16;
|
|
input += 16;
|
|
}
|
|
|
|
if( leftover )
|
|
{
|
|
/* If we are on the leftover bytes in a decrypt operation, we need to
|
|
* use the previous tweak for these bytes (as saved in prev_tweak). */
|
|
unsigned char *t = mode == MBEDTLS_AES_DECRYPT ? prev_tweak : tweak;
|
|
|
|
/* We are now on the final part of the data unit, which doesn't divide
|
|
* evenly by 16. It's time for ciphertext stealing. */
|
|
size_t i;
|
|
unsigned char *prev_output = output - 16;
|
|
|
|
/* Copy ciphertext bytes from the previous block to our output for each
|
|
* byte of cyphertext we won't steal. At the same time, copy the
|
|
* remainder of the input for this final round (since the loop bounds
|
|
* are the same). */
|
|
for( i = 0; i < leftover; i++ )
|
|
{
|
|
output[i] = prev_output[i];
|
|
tmp[i] = input[i] ^ t[i];
|
|
}
|
|
|
|
/* Copy ciphertext bytes from the previous block for input in this
|
|
* round. */
|
|
for( ; i < 16; i++ )
|
|
tmp[i] = prev_output[i] ^ t[i];
|
|
|
|
ret = esp_aes_crypt_ecb( &ctx->crypt, mode, tmp, tmp );
|
|
if( ret != 0 )
|
|
return ret;
|
|
|
|
/* Write the result back to the previous block, overriding the previous
|
|
* output we copied. */
|
|
for( i = 0; i < 16; i++ )
|
|
prev_output[i] = tmp[i] ^ t[i];
|
|
}
|
|
|
|
return( 0 );
|
|
}
|