tillitis-key/hw/application_fpga/fw/tk1/lib.c
Joachim Strömbergson 6d0a761e65
Make memeq function side channel silent
Signed-off-by: Joachim Strömbergson <joachim@assured.se>
2023-07-04 09:04:23 +02:00

152 lines
2.7 KiB
C

/*
* Copyright (C) 2022 - Tillitis AB
* SPDX-License-Identifier: GPL-2.0-only
*/
#include "lib.h"
#include "assert.h"
#include "types.h"
#ifndef NOCONSOLE
struct {
uint32_t arr[2];
} static volatile tohost __attribute__((section(".htif")));
struct {
uint32_t arr[2];
} /*@unused@*/ static volatile fromhost __attribute__((section(".htif")));
static void htif_send(uint8_t dev, uint8_t cmd, int64_t data)
{
/* endian neutral encoding with ordered 32-bit writes */
union {
uint32_t arr[2];
uint64_t val;
} encode = {.val = (uint64_t)dev << 56 | (uint64_t)cmd << 48 | data};
tohost.arr[0] = encode.arr[0];
tohost.arr[1] = encode.arr[1];
}
static void htif_set_tohost(uint8_t dev, uint8_t cmd, int64_t data)
{
/* send data with specified device and command */
while (tohost.arr[0]) {
#ifndef S_SPLINT_S
asm volatile("" : : "r"(fromhost.arr[0]));
asm volatile("" : : "r"(fromhost.arr[1]));
#endif
}
htif_send(dev, cmd, data);
}
static void htif_putchar(char ch)
{
htif_set_tohost((uint8_t)1, (uint8_t)1, (int64_t)ch & 0xff);
}
void htif_puts(const char *s)
{
while (*s != '\0')
htif_putchar(*s++);
}
void htif_hexdump(void *buf, int len)
{
uint8_t *byte_buf = (uint8_t *)buf;
for (int i = 0; i < len; i++) {
htif_puthex(byte_buf[i]);
if (i % 2 == 1) {
(void)htif_putchar(' ');
}
if (i != 1 && i % 16 == 1) {
htif_lf();
}
}
htif_lf();
}
void htif_putc(char ch)
{
htif_putchar(ch);
}
void htif_lf()
{
htif_putchar('\n');
}
void htif_puthex(uint8_t c)
{
unsigned int upper = (c >> 4) & 0xf;
unsigned int lower = c & 0xf;
htif_putchar(upper < 10 ? '0' + upper : 'a' - 10 + upper);
htif_putchar(lower < 10 ? '0' + lower : 'a' - 10 + lower);
}
void htif_putinthex(const uint32_t n)
{
uint8_t *buf = (uint8_t *)&n;
htif_puts("0x");
for (int i = 3; i > -1; i--) {
htif_puthex(buf[i]);
}
}
#endif
void *memset(void *dest, int c, unsigned n)
{
uint8_t *s = dest;
for (; n; n--, s++)
*s = (uint8_t)c;
return dest;
}
void memcpy_s(void *dest, size_t destsize, const void *src, size_t n)
{
assert(dest != NULL);
assert(src != NULL);
assert(destsize >= n);
uint8_t *src_byte = (uint8_t *)src;
uint8_t *dest_byte = (uint8_t *)dest;
for (size_t i = 0; i < n; i++) {
dest_byte[i] = src_byte[i];
}
}
void wordcpy_s(void *dest, size_t destsize, const void *src, size_t n)
{
assert(dest != NULL);
assert(src != NULL);
assert(destsize >= n);
uint32_t *src_word = (uint32_t *)src;
uint32_t *dest_word = (uint32_t *)dest;
for (size_t i = 0; i < n; i++) {
dest_word[i] = src_word[i];
}
}
int memeq(void *dest, const void *src, size_t n)
{
uint8_t *src_byte = (uint8_t *)src;
uint8_t *dest_byte = (uint8_t *)dest;
int res = -1;
for (size_t i = 0; i < n; i++) {
if (dest_byte[i] != src_byte[i]) {
res = 0;
}
}
return res;
}