fix(mbedtls): Fixed the transmission of return values of the esp-aes APIs

- Earlier, some intermediate return values were not stored and returned,
thus incorrect return values used to get transmitted to the upper layer of APIs.

- Also, zeroised the output buffer in case of error condition.
This commit is contained in:
harshal.patil 2023-07-12 14:07:43 +05:30
parent 4fc8964ec3
commit ae3026a60b
3 changed files with 102 additions and 39 deletions

View File

@ -73,6 +73,10 @@ void esp_aes_release_hardware( void )
/* Run a single 16 byte block of AES, using the hardware engine.
*
* Call only while holding esp_aes_acquire_hardware().
*
* The function esp_aes_block zeroises the output buffer in the case of following conditions:
* 1. If key is not written in the hardware
* 2. If the fault injection check failed
*/
static int esp_aes_block(esp_aes_context *ctx, const void *input, void *output)
{
@ -86,7 +90,7 @@ static int esp_aes_block(esp_aes_context *ctx, const void *input, void *output)
key write to hardware. Treat this as a fatal error and zero the output block.
*/
if (ctx->key_in_hardware != ctx->key_bytes) {
bzero(output, 16);
mbedtls_platform_zeroize(output, 16);
return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
}
i0 = input_words[0];
@ -190,7 +194,6 @@ int esp_aes_crypt_ecb(esp_aes_context *ctx,
ctx->key_in_hardware = aes_hal_setkey(ctx->key, ctx->key_bytes, mode);
r = esp_aes_block(ctx, input, output);
esp_aes_release_hardware();
return r;
}
@ -205,6 +208,7 @@ int esp_aes_crypt_cbc(esp_aes_context *ctx,
const unsigned char *input,
unsigned char *output )
{
int ret = -1;
uint32_t *output_words = (uint32_t *)output;
const uint32_t *input_words = (const uint32_t *)input;
uint32_t *iv_words = (uint32_t *)iv;
@ -226,7 +230,10 @@ int esp_aes_crypt_cbc(esp_aes_context *ctx,
if ( mode == ESP_AES_DECRYPT ) {
while ( length > 0 ) {
memcpy(temp, input_words, 16);
esp_aes_block(ctx, input_words, output_words);
ret = esp_aes_block(ctx, input_words, output_words);
if (ret != 0) {
goto cleanup;
}
output_words[0] = output_words[0] ^ iv_words[0];
output_words[1] = output_words[1] ^ iv_words[1];
@ -247,7 +254,11 @@ int esp_aes_crypt_cbc(esp_aes_context *ctx,
output_words[2] = input_words[2] ^ iv_words[2];
output_words[3] = input_words[3] ^ iv_words[3];
esp_aes_block(ctx, output_words, output_words);
ret = esp_aes_block(ctx, output_words, output_words);
if (ret != 0) {
goto cleanup;
}
memcpy( iv_words, output_words, 16 );
input_words += 4;
@ -255,10 +266,11 @@ int esp_aes_crypt_cbc(esp_aes_context *ctx,
length -= 16;
}
}
ret = 0;
cleanup:
esp_aes_release_hardware();
return 0;
return ret;
}
/*
@ -272,7 +284,7 @@ int esp_aes_crypt_cfb128(esp_aes_context *ctx,
const unsigned char *input,
unsigned char *output )
{
int c;
int c, ret = -1;
size_t n = *iv_off;
if (!valid_key_length(ctx)) {
@ -286,7 +298,10 @@ int esp_aes_crypt_cfb128(esp_aes_context *ctx,
if ( mode == ESP_AES_DECRYPT ) {
while ( length-- ) {
if ( n == 0 ) {
esp_aes_block(ctx, iv, iv);
ret = esp_aes_block(ctx, iv, iv);
if (ret != 0) {
goto cleanup;
}
}
c = *input++;
@ -298,7 +313,10 @@ int esp_aes_crypt_cfb128(esp_aes_context *ctx,
} else {
while ( length-- ) {
if ( n == 0 ) {
esp_aes_block(ctx, iv, iv);
ret = esp_aes_block(ctx, iv, iv);
if (ret != 0) {
goto cleanup;
}
}
iv[n] = *output++ = (unsigned char)( iv[n] ^ *input++ );
@ -308,10 +326,11 @@ int esp_aes_crypt_cfb128(esp_aes_context *ctx,
}
*iv_off = n;
ret = 0;
cleanup:
esp_aes_release_hardware();
return 0;
return ret;
}
/*
@ -324,6 +343,7 @@ int esp_aes_crypt_cfb8(esp_aes_context *ctx,
const unsigned char *input,
unsigned char *output )
{
int ret = -1;
unsigned char c;
unsigned char ov[17];
@ -338,7 +358,10 @@ int esp_aes_crypt_cfb8(esp_aes_context *ctx,
while ( length-- ) {
memcpy( ov, iv, 16 );
esp_aes_block(ctx, iv, iv);
ret = esp_aes_block(ctx, iv, iv);
if (ret != 0) {
goto cleanup;
}
if ( mode == ESP_AES_DECRYPT ) {
ov[16] = *input;
@ -352,10 +375,11 @@ int esp_aes_crypt_cfb8(esp_aes_context *ctx,
memcpy( iv, ov + 1, 16 );
}
ret = 0;
cleanup:
esp_aes_release_hardware();
return 0;
return ret;
}
/*
@ -370,6 +394,7 @@ int esp_aes_crypt_ctr(esp_aes_context *ctx,
unsigned char *output )
{
int c, i;
int ret = -1;
size_t n = *nc_off;
if (!valid_key_length(ctx)) {
@ -383,7 +408,10 @@ int esp_aes_crypt_ctr(esp_aes_context *ctx,
while ( length-- ) {
if ( n == 0 ) {
esp_aes_block(ctx, nonce_counter, stream_block);
ret = esp_aes_block(ctx, nonce_counter, stream_block);
if (ret != 0) {
goto cleanup;
}
for ( i = 16; i > 0; i-- ) {
if ( ++nonce_counter[i - 1] != 0 ) {
@ -398,10 +426,11 @@ int esp_aes_crypt_ctr(esp_aes_context *ctx,
}
*nc_off = n;
ret = 0;
cleanup:
esp_aes_release_hardware();
return 0;
return ret;
}
/*
@ -414,7 +443,7 @@ int esp_aes_crypt_ofb(esp_aes_context *ctx,
const unsigned char *input,
unsigned char *output )
{
int ret = 0;
int ret = -1;
size_t n;
if (ctx == NULL || iv_off == NULL || iv == NULL ||
@ -439,7 +468,10 @@ int esp_aes_crypt_ofb(esp_aes_context *ctx,
while (length--) {
if ( n == 0 ) {
esp_aes_block(ctx, iv, iv);
ret = esp_aes_block(ctx, iv, iv);
if (ret != 0) {
goto cleanup;
}
}
*output++ = *input++ ^ iv[n];
@ -447,7 +479,9 @@ int esp_aes_crypt_ofb(esp_aes_context *ctx,
}
*iv_off = n;
ret = 0;
cleanup:
esp_aes_release_hardware();
return ( ret );

View File

@ -181,7 +181,10 @@ static esp_err_t esp_aes_isr_initialise( void )
return ESP_FAIL;
}
esp_intr_alloc(ETS_AES_INTR_SOURCE, 0, esp_aes_complete_isr, NULL, NULL);
esp_err_t ret = esp_intr_alloc(ETS_AES_INTR_SOURCE, 0, esp_aes_complete_isr, NULL, NULL);
if (ret != ESP_OK) {
return ret;
}
}
/* AES is clocked proportionally to CPU clock, take power management lock */
@ -235,6 +238,8 @@ static int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input,
/* Output buffers in external ram needs to be 16-byte aligned and DMA cant access input in the iCache mem range,
reallocate them into internal memory and encrypt in chunks to avoid
having to malloc too big of a buffer
The function esp_aes_process_dma_ext_ram zeroises the output buffer in the case of memory allocation failure.
*/
static int esp_aes_process_dma_ext_ram(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, uint8_t *stream_out, bool realloc_input, bool realloc_output)
@ -251,9 +256,9 @@ static int esp_aes_process_dma_ext_ram(esp_aes_context *ctx, const unsigned char
input_buf = heap_caps_malloc(chunk_len, MALLOC_CAP_DMA);
if (input_buf == NULL) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Failed to allocate memory");
ret = -1;
goto cleanup;
return -1;
}
}
@ -261,9 +266,9 @@ static int esp_aes_process_dma_ext_ram(esp_aes_context *ctx, const unsigned char
output_buf = heap_caps_malloc(chunk_len, MALLOC_CAP_DMA);
if (output_buf == NULL) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Failed to allocate memory");
ret = -1;
goto cleanup;
return -1;
}
} else {
output_buf = output;
@ -307,7 +312,13 @@ cleanup:
return ret;
}
/* Encrypt/decrypt the input using DMA */
/* Encrypt/decrypt the input using DMA
* The function esp_aes_process_dma zeroises the output buffer in the case of following conditions:
* 1. If key is not written in the hardware
* 2. Memory allocation failures
* 3. If AES interrupt is enabled and ISR initialisation fails
* 4. Failure in any of the AES operations
*/
static int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, uint8_t *stream_out)
{
lldesc_t *in_desc_head = NULL, *out_desc_head = NULL;
@ -331,7 +342,7 @@ static int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input,
key write to hardware. Treat this as a fatal error and zero the output block.
*/
if (ctx->key_in_hardware != ctx->key_bytes) {
bzero(output, len);
mbedtls_platform_zeroize(output, len);
return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
}
@ -368,9 +379,9 @@ static int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input,
/* Allocate both in and out descriptors to save a malloc/free per function call */
block_desc = heap_caps_calloc(lldesc_num * 2, sizeof(lldesc_t), MALLOC_CAP_DMA);
if (block_desc == NULL) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Failed to allocate memory");
ret = -1;
goto cleanup;
return -1;
}
block_in_desc = block_desc;
@ -416,6 +427,7 @@ static int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input,
if (len > AES_DMA_INTR_TRIG_LEN) {
use_intr = true;
if (esp_aes_isr_initialise() == ESP_FAIL) {
ESP_LOGE(TAG, "ESP-AES ISR initialisation failed");
ret = -1;
goto cleanup;
}
@ -449,6 +461,9 @@ static int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input,
}
cleanup:
if (ret != 0) {
mbedtls_platform_zeroize(output, len);
}
free(block_desc);
return ret;
}
@ -456,7 +471,13 @@ cleanup:
#if SOC_AES_SUPPORT_GCM
/* Encrypt/decrypt with AES-GCM the input using DMA */
/* Encrypt/decrypt with AES-GCM the input using DMA
* The function esp_aes_process_dma_gcm zeroises the output buffer in the case of following conditions:
* 1. If key is not written in the hardware
* 2. Memory allocation failures
* 3. If AES interrupt is enabled and ISR initialisation fails
* 4. Failure in any of the AES operations
*/
int esp_aes_process_dma_gcm(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, lldesc_t *aad_desc, size_t aad_len)
{
lldesc_t *in_desc_head = NULL, *out_desc_head = NULL, *len_desc = NULL;
@ -480,7 +501,7 @@ int esp_aes_process_dma_gcm(esp_aes_context *ctx, const unsigned char *input, un
key write to hardware. Treat this as a fatal error and zero the output block.
*/
if (ctx->key_in_hardware != ctx->key_bytes) {
bzero(output, len);
mbedtls_platform_zeroize(output, len);
return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
}
@ -490,9 +511,9 @@ int esp_aes_process_dma_gcm(esp_aes_context *ctx, const unsigned char *input, un
/* Allocate both in and out descriptors to save a malloc/free per function call, add 1 for length descriptor */
block_desc = heap_caps_calloc( (lldesc_num * 2) + 1, sizeof(lldesc_t), MALLOC_CAP_DMA);
if (block_desc == NULL) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Failed to allocate memory");
ret = -1;
goto cleanup;
return -1;
}
block_in_desc = block_desc;
@ -539,6 +560,7 @@ int esp_aes_process_dma_gcm(esp_aes_context *ctx, const unsigned char *input, un
if (len > AES_DMA_INTR_TRIG_LEN) {
use_intr = true;
if (esp_aes_isr_initialise() == ESP_FAIL) {
ESP_LOGE(TAG, "ESP-AES ISR initialisation failed");
ret = -1;
goto cleanup;
}
@ -566,6 +588,9 @@ int esp_aes_process_dma_gcm(esp_aes_context *ctx, const unsigned char *input, un
}
cleanup:
if (ret != 0) {
mbedtls_platform_zeroize(output, len);
}
free(block_desc);
return ret;
}
@ -779,13 +804,13 @@ int esp_aes_crypt_cfb8(esp_aes_context *ctx,
aes_hal_mode_init(ESP_AES_BLOCK_MODE_CFB8);
aes_hal_set_iv(iv);
r = esp_aes_process_dma(ctx, input, output, block_bytes, NULL);
aes_hal_read_iv(iv);
if (r != 0) {
esp_aes_release_hardware();
return r;
}
aes_hal_read_iv(iv);
length -= block_bytes;
input += block_bytes;
output += block_bytes;

View File

@ -389,7 +389,6 @@ int esp_aes_gcm_starts( esp_gcm_context *ctx,
aes_hal_gcm_calc_hash(ctx->H);
esp_aes_release_hardware();
gcm_gen_table(ctx);
}
@ -454,7 +453,10 @@ int esp_aes_gcm_update( esp_gcm_context *ctx,
}
/* Output = GCTR(J0, Input): Encrypt/Decrypt the input */
esp_aes_crypt_ctr(&ctx->aes_ctx, length, &nc_off, nonce_counter, stream, input, output);
int ret = esp_aes_crypt_ctr(&ctx->aes_ctx, length, &nc_off, nonce_counter, stream, input, output);
if (ret != 0) {
return ret;
}
/* ICB gets auto incremented after GCTR operation here so update the context */
memcpy(ctx->J0, nonce_counter, AES_BLOCK_BYTES);
@ -489,9 +491,7 @@ int esp_aes_gcm_finish( esp_gcm_context *ctx,
esp_gcm_ghash(ctx, len_block, AES_BLOCK_BYTES, ctx->ghash);
/* Tag T = GCTR(J0, ) where T is truncated to tag_len */
esp_aes_crypt_ctr(&ctx->aes_ctx, tag_len, &nc_off, ctx->ori_j0, stream, ctx->ghash, tag);
return 0;
return esp_aes_crypt_ctr(&ctx->aes_ctx, tag_len, &nc_off, ctx->ori_j0, stream, ctx->ghash, tag);
}
/* Due to restrictions in the hardware (e.g. need to do the whole conversion in one go),
@ -657,6 +657,10 @@ int esp_aes_gcm_crypt_and_tag( esp_gcm_context *ctx,
aes_hal_gcm_set_j0(ctx->J0);
ret = esp_aes_process_dma_gcm(&ctx->aes_ctx, input, output, length, aad_head_desc, aad_len);
if (ret != 0) {
esp_aes_release_hardware();
return ret;
}
aes_hal_gcm_read_tag(tag, tag_len);