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adustmadustm
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Fix multi context for AES CBC and ECB mode
Fix mbed-os-example-tls-client use case
1 parent 458b0ec commit c1fcae6

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2 files changed

+105
-21
lines changed

2 files changed

+105
-21
lines changed

‎features/mbedtls/targets/TARGET_STM/aes_alt.c

Lines changed: 102 additions & 21 deletions
Original file line numberDiff line numberDiff line change
@@ -129,6 +129,7 @@ int mbedtls_aes_crypt_ecb( mbedtls_aes_context *ctx,
129129

130130
/* allow multi-instance of CRYP use: restore context for CRYP hw module */
131131
ctx->hcryp_aes.Instance->CR = ctx->ctx_save_cr;
132+
ctx->hcryp_aes.Phase = HAL_CRYP_PHASE_READY;
132133

133134
if(mode == MBEDTLS_AES_DECRYPT) { /* AES decryption */
134135
ctx->hcryp_aes.Init.DataType = CRYP_DATATYPE_8B;
@@ -147,31 +148,93 @@ int mbedtls_aes_crypt_ecb( mbedtls_aes_context *ctx,
147148

148149
#if defined(MBEDTLS_CIPHER_MODE_CBC)
149150
#if defined (TARGET_STM32L486xG)
151+
static int st_cbc_restore_context(mbedtls_aes_context *ctx){
152+
uint32_t tickstart;
153+
tickstart = HAL_GetTick();
154+
while((ctx->hcryp_aes.Instance->SR & AES_SR_BUSY) != 0){
155+
if ((HAL_GetTick() - tickstart) > ST_AES_TIMEOUT) {
156+
return 1; // timeout: CRYP processor is busy
157+
}
158+
}
159+
/* allow multi-instance of CRYP use: restore context for CRYP hw module */
160+
ctx->hcryp_aes.Instance->CR = ctx->ctx_save_cr;
161+
return 0;
162+
}
163+
static int st_cbc_save_context(mbedtls_aes_context *ctx){
164+
uint32_t tickstart;
165+
166+
tickstart = HAL_GetTick();
167+
while((ctx->hcryp_aes.Instance->SR & AES_SR_BUSY) != 0){
168+
if ((HAL_GetTick() - tickstart) > ST_AES_TIMEOUT) {
169+
return 1; // timeout: CRYP processor is busy
170+
}
171+
}
172+
/* allow multi-instance of CRYP use: save context for CRYP HW module CR */
173+
ctx->ctx_save_cr = ctx->hcryp_aes.Instance->CR;
174+
175+
return 0;
176+
}
150177
static int st_hal_cryp_cbc( mbedtls_aes_context *ctx, uint32_t opmode, size_t length,
151178
unsigned char iv[16], uint8_t *input, uint8_t *output)
152179
{
153180
int status = 0;
154181
ctx->hcryp_aes.Init.pInitVect = &iv[0]; // used in process, not in the init
155-
if ((ctx->hcryp_aes.Init.OperatingMode != opmode) || \
156-
(ctx->hcryp_aes.Init.ChainingMode != CRYP_CHAINMODE_AES_CBC) || \
157-
(ctx->hcryp_aes.Init.KeyWriteFlag != CRYP_KEY_WRITE_ENABLE)) {
158-
159-
/* Re-initialize AES IP with proper parameters */
160-
if (HAL_CRYP_DeInit(&ctx->hcryp_aes) != HAL_OK)
161-
return HAL_ERROR;
162-
ctx->hcryp_aes.Init.OperatingMode = opmode;
163-
ctx->hcryp_aes.Init.ChainingMode = CRYP_CHAINMODE_AES_CBC;
164-
ctx->hcryp_aes.Init.KeyWriteFlag = CRYP_KEY_WRITE_ENABLE;
165-
if (HAL_CRYP_Init(&ctx->hcryp_aes) != HAL_OK)
166-
return HAL_ERROR;
167-
}
182+
/* At this moment only, we know we have CBC mode: Re-initialize AES
183+
IP with proper parameters and apply key and IV for multi context usecase */
184+
if (HAL_CRYP_DeInit(&ctx->hcryp_aes) != HAL_OK)
185+
return HAL_ERROR;
186+
ctx->hcryp_aes.Init.OperatingMode = opmode;
187+
ctx->hcryp_aes.Init.ChainingMode = CRYP_CHAINMODE_AES_CBC;
188+
ctx->hcryp_aes.Init.KeyWriteFlag = CRYP_KEY_WRITE_ENABLE;
189+
if (HAL_CRYP_Init(&ctx->hcryp_aes) != HAL_OK)
190+
return HAL_ERROR;
168191

169192
status = HAL_CRYPEx_AES(&ctx->hcryp_aes, input, length, output, 10);
170193

171194
return status;
172195
}
196+
#else
197+
static int st_cbc_restore_context(mbedtls_aes_context *ctx){
198+
uint32_t tickstart;
199+
tickstart = HAL_GetTick();
200+
while((ctx->hcryp_aes.Instance->SR & (CRYP_SR_IFEM | CRYP_SR_OFNE | CRYP_SR_BUSY)) != CRYP_SR_IFEM){
201+
if ((HAL_GetTick() - tickstart) > ST_AES_TIMEOUT) {
202+
return 1; // timeout: CRYP processor is busy
203+
}
204+
}
205+
ctx->hcryp_aes.Instance->CR &= ~CRYP_CR_CRYPEN;
206+
/* save initvector for multi-instance use of CRYP */
207+
ctx->hcryp_aes.Instance->IV1RR = ctx->save_iv[3];
208+
ctx->hcryp_aes.Instance->IV1LR = ctx->save_iv[2];
209+
ctx->hcryp_aes.Instance->IV0RR = ctx->save_iv[1];
210+
ctx->hcryp_aes.Instance->IV0LR = ctx->save_iv[0];
211+
ctx->hcryp_aes.Phase = HAL_CRYP_PHASE_READY;
212+
/* allow multi-instance of CRYP use: restore context for CRYP hw module */
213+
ctx->hcryp_aes.Instance->CR = ctx->ctx_save_cr;
214+
return 0;
215+
}
216+
static int st_cbc_save_context(mbedtls_aes_context *ctx){
217+
uint32_t tickstart;
218+
tickstart = HAL_GetTick();
219+
while((ctx->hcryp_aes.Instance->SR & (CRYP_SR_IFEM | CRYP_SR_OFNE | CRYP_SR_BUSY)) != CRYP_SR_IFEM){
220+
if ((HAL_GetTick() - tickstart) > ST_AES_TIMEOUT) {
221+
return 1; // timeout: CRYP processor is busy
222+
}
223+
}
224+
/* allow multi-instance of CRYP use: save context for CRYP HW module CR */
225+
ctx->ctx_save_cr = ctx->hcryp_aes.Instance->CR;
226+
ctx->hcryp_aes.Instance->CR &= ~CRYP_CR_CRYPEN;
227+
/* save initvector for multi-instance use of CRYP */
228+
ctx->save_iv[3] = ctx->hcryp_aes.Instance->IV1RR;
229+
ctx->save_iv[2] = ctx->hcryp_aes.Instance->IV1LR;
230+
ctx->save_iv[1] = ctx->hcryp_aes.Instance->IV0RR;
231+
ctx->save_iv[0] = ctx->hcryp_aes.Instance->IV0LR;
232+
if ((ctx->ctx_save_cr & CRYP_CR_CRYPEN) == CRYP_CR_CRYPEN) {
233+
ctx->hcryp_aes.Instance->CR &= CRYP_CR_CRYPEN;
234+
}
235+
return 0;
236+
}
173237
#endif /* TARGET_STM32L486xG */
174-
175238
int mbedtls_aes_crypt_cbc( mbedtls_aes_context *ctx,
176239
int mode,
177240
size_t length,
@@ -180,23 +243,43 @@ int mbedtls_aes_crypt_cbc( mbedtls_aes_context *ctx,
180243
unsigned char *output )
181244
{
182245
int status = 0;
246+
uint32_t *iv_ptr = (uint32_t *)&iv[0];
183247
if( length % 16 )
184248
return( MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH );
249+
ctx->hcryp_aes.Init.pInitVect = &iv[0];
250+
status |= st_cbc_restore_context(ctx);
185251
#if defined (TARGET_STM32L486xG)
186252
if( mode == MBEDTLS_AES_DECRYPT ) {
187-
status = st_hal_cryp_cbc(ctx, CRYP_ALGOMODE_KEYDERIVATION_DECRYPT, length, iv, (uint8_t *)input, (uint8_t *)output);
253+
status |= st_hal_cryp_cbc(ctx, CRYP_ALGOMODE_KEYDERIVATION_DECRYPT, length, iv, (uint8_t *)input, (uint8_t *)output);
254+
// update IV
255+
uint32_t tickstart;
256+
tickstart = HAL_GetTick();
257+
while((ctx->hcryp_aes.Instance->SR & AES_SR_BUSY) != 0){
258+
if ((HAL_GetTick() - tickstart) > ST_AES_TIMEOUT) {
259+
return 1; // timeout: CRYP processor is busy
260+
}
261+
}
262+
ctx->ctx_save_cr = ctx->hcryp_aes.Instance->CR;
263+
ctx->hcryp_aes.Instance->CR &= ~AES_CR_EN;
264+
*iv_ptr++ = ctx->hcryp_aes.Instance->IVR3;
265+
*iv_ptr++ = ctx->hcryp_aes.Instance->IVR2;
266+
*iv_ptr++ = ctx->hcryp_aes.Instance->IVR1;
267+
*iv_ptr++ = ctx->hcryp_aes.Instance->IVR0;
268+
188269
} else {
189-
status = st_hal_cryp_cbc(ctx, CRYP_ALGOMODE_ENCRYPT, length, iv, (uint8_t *)input, (uint8_t *)output);
270+
status |= st_hal_cryp_cbc(ctx, CRYP_ALGOMODE_ENCRYPT, length, iv, (uint8_t *)input, (uint8_t *)output);
271+
memcpy( iv, output, 16 );
190272
}
191273
#else
192-
ctx->hcryp_aes.Init.pInitVect = &iv[0];
193274

194275
if( mode == MBEDTLS_AES_DECRYPT ) {
195-
status = HAL_CRYP_AESCBC_Decrypt(&ctx->hcryp_aes, (uint8_t *)input, length, (uint8_t *)output, 10);
276+
status |= HAL_CRYP_AESCBC_Decrypt(&ctx->hcryp_aes, (uint8_t *)input, length, (uint8_t *)output, 10);
196277
} else {
197-
status = HAL_CRYP_AESCBC_Encrypt(&ctx->hcryp_aes, (uint8_t *)input, length, (uint8_t *)output, 10);
278+
status |= HAL_CRYP_AESCBC_Encrypt(&ctx->hcryp_aes, (uint8_t *)input, length, (uint8_t *)output, 10);
198279
}
199280
#endif
281+
status |= st_cbc_save_context(ctx);
282+
200283
return( status );
201284
}
202285
#endif /* MBEDTLS_CIPHER_MODE_CBC */
@@ -308,7 +391,6 @@ void mbedtls_aes_encrypt( mbedtls_aes_context *ctx,
308391
const unsigned char input[16],
309392
unsigned char output[16] )
310393
{
311-
312394
if (HAL_CRYP_AESECB_Encrypt(&ctx->hcryp_aes, (uint8_t *)input, 16, (uint8_t *)output, 10) !=0) {
313395
// error found to be returned
314396
}
@@ -319,7 +401,6 @@ void mbedtls_aes_decrypt( mbedtls_aes_context *ctx,
319401
const unsigned char input[16],
320402
unsigned char output[16] )
321403
{
322-
323404
if(HAL_CRYP_AESECB_Decrypt(&ctx->hcryp_aes, (uint8_t *)input, 16, (uint8_t *)output, 10)) {
324405
// error found to be returned
325406
}

‎features/mbedtls/targets/TARGET_STM/aes_alt.h

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -30,6 +30,8 @@
3030
#ifdef __cplusplus
3131
extern "C" {
3232
#endif
33+
34+
#define ST_AES_TIMEOUT ((uint32_t) 3)
3335
/**
3436
* \brief AES context structure
3537
*
@@ -43,6 +45,7 @@ typedef struct
4345
unsigned char aes_key[32]; /* Decryption key */
4446
CRYP_HandleTypeDef hcryp_aes;
4547
uint32_t ctx_save_cr; /* save context for multi-instance */
48+
uint32_t save_iv[4]; /* save context for multi-instance */
4649
}
4750
mbedtls_aes_context;
4851

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