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[M487/NUC472] Unified code-path for remaining bytes of TRNG_Get

pull/5454/head
cyliangtw 2017-11-08 19:56:12 +08:00
parent 4118afa259
commit 76c2c19853
2 changed files with 29 additions and 27 deletions
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29
targets/TARGET_NUVOTON/TARGET_M480/trng_api.c
View File

@ -28,6 +28,11 @@
static volatile int g_PRNG_done; static volatile int g_PRNG_done;
volatile int g_AES_done; volatile int g_AES_done;
/* Implementation that should never be optimized out by the compiler */
static void trng_zeroize( void *v, size_t n ) {
volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
}
void CRYPTO_IRQHandler() void CRYPTO_IRQHandler()
{ {
if (PRNG_GET_INT_FLAG()) { if (PRNG_GET_INT_FLAG()) {
@ -78,23 +83,19 @@ int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_l
{ {
(void)obj; (void)obj;
unsigned char tmpBuff[32]; unsigned char tmpBuff[32];
*output_length = 0; *output_length = 0;
if (length < 32) {
for (unsigned i = 0; i < (length/32); i++) {
trng_get(output);
*output_length += 32;
output += 32;
}
if( length > *output_length ) {
trng_zeroize(tmpBuff, sizeof(tmpBuff));
trng_get(tmpBuff); trng_get(tmpBuff);
memcpy(output, &tmpBuff, length); memcpy(output, &tmpBuff, (length - *output_length));
*output_length = length; *output_length = length;
} else {
for (unsigned i = 0; i < (length/32); i++) {
trng_get(output);
*output_length += 32;
output += 32;
}
if( length > *output_length ) {
trng_get(tmpBuff);
memcpy(output, &tmpBuff, (length - *output_length));
*output_length = length;
}
} }
return 0; return 0;

27
targets/TARGET_NUVOTON/TARGET_NUC472/trng_api.c
View File

@ -33,6 +33,11 @@
static volatile int g_PRNG_done; static volatile int g_PRNG_done;
volatile int g_AES_done; volatile int g_AES_done;
/* Implementation that should never be optimized out by the compiler */
static void trng_zeroize( void *v, size_t n ) {
volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
}
void CRYPTO_IRQHandler() void CRYPTO_IRQHandler()
{ {
if (PRNG_GET_INT_FLAG()) { if (PRNG_GET_INT_FLAG()) {
@ -85,21 +90,17 @@ int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_l
unsigned char tmpBuff[32]; unsigned char tmpBuff[32];
*output_length = 0; *output_length = 0;
if (length < 32) {
for (unsigned i = 0; i < (length/32); i++) {
trng_get(output);
*output_length += 32;
output += 32;
}
if( length > *output_length ) {
trng_zeroize(tmpBuff, sizeof(tmpBuff));
trng_get(tmpBuff); trng_get(tmpBuff);
memcpy(output, &tmpBuff, length); memcpy(output, &tmpBuff, (length - *output_length));
*output_length = length; *output_length = length;
} else {
for (unsigned i = 0; i < (length/32); i++) {
trng_get(output);
*output_length += 32;
output += 32;
}
if( length > *output_length ) {
trng_get(tmpBuff);
memcpy(output, &tmpBuff, (length - *output_length));
*output_length = length;
}
} }
return 0; return 0;