WolfSSL
/
wolfBoot
mirror of https://github.com/wolfSSL/wolfBoot.git
1
0
Fork 0
Code Issues Releases Wiki Activity

hal_trng_get_entropy: handle unaligned `out`

pull/727/head
Mattia Moffa 2026-03-19 16:22:34 +01:00
parent 175d2b3026
commit 74de388458
1 changed files with 35 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

72
hal/mcxn.c
View File

@ -228,53 +228,51 @@ void hal_trng_fini(void)
/* Don't disable ELS, it might be used by other actors */
}
int hal_trng_get_entropy(unsigned char *out, unsigned int len)
static int els_rnd_req(void *out, uint32_t len)
{
/* Implemented as a RND_REQ command to the ELS */
uint32_t aligned_len = len & ~3U;
uint32_t status;
/* Wait for ELS to be ready */
while (ELS->ELS_STATUS & S50_ELS_STATUS_ELS_BUSY_MASK)
;
ELS->ELS_DMA_RES0 = (uint32_t)(uintptr_t)out;
ELS->ELS_DMA_RES0_LEN = len;
ELS->ELS_CMDCFG0 = 0;
ELS->ELS_CTRL = S50_ELS_CTRL_ELS_EN(1)
| S50_ELS_CTRL_ELS_START(1)
| S50_ELS_CTRL_ELS_CMD(ELS_CMD_RND_REQ);
while (ELS->ELS_STATUS & S50_ELS_STATUS_ELS_BUSY_MASK)
;
return (ELS->ELS_STATUS & S50_ELS_STATUS_ELS_ERR_MASK) ? -1 : 0;
}
/* Handle the word-aligned portion */
if (aligned_len > 0) {
ELS->ELS_DMA_RES0 = (uint32_t)(uintptr_t)out;
ELS->ELS_DMA_RES0_LEN = aligned_len;
ELS->ELS_CMDCFG0 = 0;
ELS->ELS_CTRL = S50_ELS_CTRL_ELS_EN(1)
| S50_ELS_CTRL_ELS_START(1)
| S50_ELS_CTRL_ELS_CMD(ELS_CMD_RND_REQ);
int hal_trng_get_entropy(unsigned char *out, unsigned int len)
{
uint32_t tmp;
while (ELS->ELS_STATUS & S50_ELS_STATUS_ELS_BUSY_MASK)
;
status = ELS->ELS_STATUS;
if (status & S50_ELS_STATUS_ELS_ERR_MASK)
/* Handle unaligned head (up to 3 bytes) via temporary word */
if ((uintptr_t)out & 3U) {
uint32_t head = 4U - ((uintptr_t)out & 3U);
if (head > len)
head = len;
if (els_rnd_req(&tmp, 4) != 0)
return -1;
memcpy(out, &tmp, head);
out += head;
len -= head;
}
/* Handle remaining bytes (1-3) with a temporary word */
if (len > aligned_len) {
uint32_t tmp;
ELS->ELS_DMA_RES0 = (uint32_t)(uintptr_t)&tmp;
ELS->ELS_DMA_RES0_LEN = 4;
ELS->ELS_CMDCFG0 = 0;
ELS->ELS_CTRL = S50_ELS_CTRL_ELS_EN(1)
| S50_ELS_CTRL_ELS_START(1)
| S50_ELS_CTRL_ELS_CMD(ELS_CMD_RND_REQ);
while (ELS->ELS_STATUS & S50_ELS_STATUS_ELS_BUSY_MASK)
;
status = ELS->ELS_STATUS;
if (status & S50_ELS_STATUS_ELS_ERR_MASK)
/* Bulk aligned portion in one request */
if (len >= 4) {
uint32_t aligned_len = len & ~3U;
if (els_rnd_req(out, aligned_len) != 0)
return -1;
out += aligned_len;
len -= aligned_len;
}
memcpy(out + aligned_len, &tmp, len - aligned_len);
/* Handle remaining tail bytes (1-3) via temporary word */
if (len > 0) {
if (els_rnd_req(&tmp, 4) != 0)
return -1;
memcpy(out, &tmp, len);
}
return 0;