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esp32 hwcrypto: Rework hardware crypto locking

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Should protect against concurrent use of hardware crypto primitives,
with good performance.

Not necessary to call esp_aes_acquire_hardware(),
esp_sha_acquire_hardware(), etc when using these APIs. These are
provided for external users calling the hardware crypto hardware
directly, to coexist with this implementation.
This commit is contained in:
Angus Gratton
2016-09-02 18:36:26 +10:00
committed by Wu Jian Gang
parent 4167b68eef
commit 0647d1e922
8 changed files with 235 additions and 340 deletions
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209
components/esp32/hwcrypto/aes.c
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@@ -1,8 +1,10 @@
/*
* FIPS-197 compliant AES implementation
* ESP32 hardware accelerated AES implementation
* based on mbedTLS FIPS-197 compliant version.
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* Additions Copyright (C) 2016, Espressif Systems (Shanghai) PTE Ltd
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -25,22 +27,30 @@
* http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf
*/
#include <string.h>
#include "aes.h"
#include "esp_crypto.h"
#include "hwcrypto/aes.h"
#include "rom/aes.h"
#include <sys/lock.h>
/* Implementation that should never be optimized out by the compiler */
//static void bzero( void *v, size_t n ) {
// volatile unsigned char *p = v; while( n-- ) *p++ = 0;
//}
static _lock_t aes_lock;
void esp_aes_acquire_hardware( void )
{
/* newlib locks lazy initialize on ESP-IDF */
_lock_acquire(&aes_lock);
ets_aes_enable();
}
void esp_aes_release_hardware( void )
{
uint8_t zero[256/8] = { 0 };
ets_aes_setkey_enc(zero, AES256);
ets_aes_disable();
_lock_release(&aes_lock);
}
void esp_aes_init( AES_CTX *ctx )
{
memset( ctx, 0, sizeof( AES_CTX ) );
AES_LOCK();
AES_TAKE();
ets_aes_enable();
AES_UNLOCK();
bzero( ctx, sizeof( AES_CTX ) );
}
void esp_aes_free( AES_CTX *ctx )
@@ -50,117 +60,94 @@ void esp_aes_free( AES_CTX *ctx )
}
bzero( ctx, sizeof( AES_CTX ) );
}
AES_LOCK();
AES_GIVE();
if (false == AES_IS_USED()) {
ets_aes_disable();
/* Translate number of bits to an AES_BITS enum */
static int keybits_to_aesbits(unsigned int keybits)
{
switch (keybits) {
case 128:
return AES128;
case 192:
return AES192;
break;
case 256:
return AES256;
default:
return ( ERR_AES_INVALID_KEY_LENGTH );
}
AES_UNLOCK();
}
/*
* AES key schedule (encryption)
*
*/
int esp_aes_setkey_enc( AES_CTX *ctx, const unsigned char *key,
unsigned int keybits )
{
enum AES_BITS keybit;
uint16_t keybyte = keybits / 8;
switch (keybits) {
case 128:
keybit = AES128;
break;
case 192:
keybit = AES192;
break;
case 256:
keybit = AES256;
break;
default:
return ( ERR_AES_INVALID_KEY_LENGTH );
uint16_t keybytes = keybits / 8;
int aesbits = keybits_to_aesbits(keybits);
if (aesbits < 0) {
return aesbits;
}
if (ctx->enc.keyflag == false) {
ctx->enc.keyflag = true;
ctx->enc.keybits = keybits;
memset(ctx->enc.key, 0, sizeof(ctx->enc.key));
memcpy(ctx->enc.key, key, keybyte);
} else {
ets_aes_setkey_enc(key, keybit);
}
ctx->enc.aesbits = aesbits;
bzero(ctx->enc.key, sizeof(ctx->enc.key));
memcpy(ctx->enc.key, key, keybytes);
return 0;
}
/*
* AES key schedule (decryption)
*
*/
int esp_aes_setkey_dec( AES_CTX *ctx, const unsigned char *key,
unsigned int keybits )
{
enum AES_BITS keybit;
uint16_t keybyte = keybits / 8;
switch (keybits) {
case 128:
keybit = AES128;
break;
case 192:
keybit = AES192;
break;
case 256:
keybit = AES256;
break;
default:
return ( ERR_AES_INVALID_KEY_LENGTH );
uint16_t keybytes = keybits / 8;
int aesbits = keybits_to_aesbits(keybits);
if (aesbits < 0) {
return aesbits;
}
if (ctx->dec.keyflag == false) {
ctx->dec.keyflag = true;
ctx->dec.keybits = keybits;
memset(ctx->dec.key, 0, sizeof(ctx->dec.key));
memcpy(ctx->dec.key, key, keybyte);
} else {
ets_aes_setkey_dec(key, keybit);
}
ctx->dec.aesbits = aesbits;
bzero(ctx->dec.key, sizeof(ctx->dec.key));
memcpy(ctx->dec.key, key, keybytes);
return 0;
}
static void esp_aes_process_enable(AES_CTX *ctx, int mode)
/*
* Inner AES-ECB function. Call only when protected by esp_aes_acquire_hardware().
*
* Optimisation to prevent overhead of locking each time when
* encrypting many blocks in sequence.
*/
static int esp_aes_crypt_ecb_inner( AES_CTX *ctx,
int mode,
const unsigned char input[16],
unsigned char output[16] )
{
if ( mode == AES_ENCRYPT ) {
esp_aes_setkey_enc(ctx, ctx->enc.key, ctx->enc.keybits);
ets_aes_setkey_enc(ctx->enc.key, ctx->enc.aesbits);
ets_aes_crypt(input, output);
} else {
esp_aes_setkey_dec(ctx, ctx->dec.key, ctx->dec.keybits);
ets_aes_setkey_dec(ctx->enc.key, ctx->enc.aesbits);
/* TODO: previous commit esp_aes_decrypt function calls this but this is not correct! */
ets_aes_crypt(input, output);
}
return;
}
static void esp_aes_process_disable(AES_CTX *ctx, int mode)
{
return 0;
}
/*
* AES-ECB block encryption
*/
void esp_aes_encrypt( AES_CTX *ctx,
const unsigned char input[16],
unsigned char output[16] )
{
ets_aes_crypt(input, output);
return ;
esp_aes_acquire_hardware();
esp_aes_crypt_ecb_inner(ctx, AES_ENCRYPT, input, output);
esp_aes_release_hardware();
}
/*
* AES-ECB block decryption
*/
@@ -169,9 +156,9 @@ void esp_aes_decrypt( AES_CTX *ctx,
const unsigned char input[16],
unsigned char output[16] )
{
ets_aes_crypt(input, output);
return ;
esp_aes_acquire_hardware();
esp_aes_crypt_ecb_inner(ctx, AES_DECRYPT, input, output);
esp_aes_release_hardware();
}
@@ -183,20 +170,9 @@ int esp_aes_crypt_ecb( AES_CTX *ctx,
const unsigned char input[16],
unsigned char output[16] )
{
AES_LOCK();
esp_aes_process_enable(ctx, mode);
if ( mode == AES_ENCRYPT ) {
esp_aes_encrypt( ctx, input, output );
} else {
esp_aes_decrypt( ctx, input, output );
}
esp_aes_process_disable(ctx, mode);
AES_UNLOCK();
esp_aes_acquire_hardware();
esp_aes_crypt_ecb_inner(ctx, mode, input, output);
esp_aes_release_hardware();
return 0;
}
@@ -218,10 +194,12 @@ int esp_aes_crypt_cbc( AES_CTX *ctx,
return ( ERR_AES_INVALID_INPUT_LENGTH );
}
esp_aes_acquire_hardware();
if ( mode == AES_DECRYPT ) {
while ( length > 0 ) {
memcpy( temp, input, 16 );
esp_aes_crypt_ecb( ctx, mode, input, output );
esp_aes_crypt_ecb_inner( ctx, mode, input, output );
for ( i = 0; i < 16; i++ ) {
output[i] = (unsigned char)( output[i] ^ iv[i] );
@@ -239,7 +217,7 @@ int esp_aes_crypt_cbc( AES_CTX *ctx,
output[i] = (unsigned char)( input[i] ^ iv[i] );
}
esp_aes_crypt_ecb( ctx, mode, output, output );
esp_aes_crypt_ecb_inner( ctx, mode, output, output );
memcpy( iv, output, 16 );
input += 16;
@@ -248,6 +226,8 @@ int esp_aes_crypt_cbc( AES_CTX *ctx,
}
}
esp_aes_release_hardware();
return 0;
}
@@ -265,10 +245,12 @@ int esp_aes_crypt_cfb128( AES_CTX *ctx,
int c;
size_t n = *iv_off;
esp_aes_acquire_hardware();
if ( mode == AES_DECRYPT ) {
while ( length-- ) {
if ( n == 0 ) {
esp_aes_crypt_ecb( ctx, AES_ENCRYPT, iv, iv );
esp_aes_crypt_ecb_inner( ctx, AES_ENCRYPT, iv, iv );
}
c = *input++;
@@ -280,7 +262,7 @@ int esp_aes_crypt_cfb128( AES_CTX *ctx,
} else {
while ( length-- ) {
if ( n == 0 ) {
esp_aes_crypt_ecb( ctx, AES_ENCRYPT, iv, iv );
esp_aes_crypt_ecb_inner( ctx, AES_ENCRYPT, iv, iv );
}
iv[n] = *output++ = (unsigned char)( iv[n] ^ *input++ );
@@ -291,6 +273,8 @@ int esp_aes_crypt_cfb128( AES_CTX *ctx,
*iv_off = n;
esp_aes_release_hardware();
return 0;
}
@@ -307,9 +291,11 @@ int esp_aes_crypt_cfb8( AES_CTX *ctx,
unsigned char c;
unsigned char ov[17];
esp_aes_acquire_hardware();
while ( length-- ) {
memcpy( ov, iv, 16 );
esp_aes_crypt_ecb( ctx, AES_ENCRYPT, iv, iv );
esp_aes_crypt_ecb_inner( ctx, AES_ENCRYPT, iv, iv );
if ( mode == AES_DECRYPT ) {
ov[16] = *input;
@@ -324,6 +310,8 @@ int esp_aes_crypt_cfb8( AES_CTX *ctx,
memcpy( iv, ov + 1, 16 );
}
esp_aes_release_hardware();
return 0;
}
@@ -341,9 +329,11 @@ int esp_aes_crypt_ctr( AES_CTX *ctx,
int c, i;
size_t n = *nc_off;
esp_aes_acquire_hardware();
while ( length-- ) {
if ( n == 0 ) {
esp_aes_crypt_ecb( ctx, AES_ENCRYPT, nonce_counter, stream_block );
esp_aes_crypt_ecb_inner( ctx, AES_ENCRYPT, nonce_counter, stream_block );
for ( i = 16; i > 0; i-- )
if ( ++nonce_counter[i - 1] != 0 ) {
@@ -358,6 +348,7 @@ int esp_aes_crypt_ctr( AES_CTX *ctx,
*nc_off = n;
esp_aes_release_hardware();
return 0;
}