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mirror of https://github.com/trezor/trezor-firmware.git synced 2024-11-12 18:49:07 +00:00

extract some pbkdf2 constants into macros

This commit is contained in:
Pavol Rusnak 2013-12-09 18:16:33 +01:00
parent 352bc42be2
commit 97067c918e

View File

@ -2,12 +2,15 @@
#include "pbkdf2.h"
#include "hmac.h"
#define HMACFUNC hmac_sha512
#define HMACLEN (512/8)
void pbkdf2(const uint8_t *pass, int passlen, uint8_t *salt, int saltlen, uint32_t iterations, uint8_t *key, int keylen)
{
uint32_t i, j, k;
uint8_t f[64], g[64];
uint32_t blocks = keylen / 64; // SHA-512
if (keylen & 63) {
uint8_t f[HMACLEN], g[HMACLEN];
uint32_t blocks = keylen / HMACLEN;
if (keylen & (HMACLEN - 1)) {
blocks++;
}
for (i = 1; i <= blocks; i++) {
@ -15,22 +18,18 @@ void pbkdf2(const uint8_t *pass, int passlen, uint8_t *salt, int saltlen, uint32
salt[saltlen + 1] = (i >> 16) & 0xFF;
salt[saltlen + 2] = (i >> 8) & 0xFF;
salt[saltlen + 3] = i & 0xFF;
hmac_sha512(pass, passlen, salt, saltlen + 4, g);
memcpy(f, g, 64);
HMACFUNC(pass, passlen, salt, saltlen + 4, g);
memcpy(f, g, HMACLEN);
for (j = 1; j < iterations; j++) {
hmac_sha512(pass, passlen, g, 64, g);
for (k = 0; k < 64; k++) {
HMACFUNC(pass, passlen, g, HMACLEN, g);
for (k = 0; k < HMACLEN; k++) {
f[k] ^= g[k];
}
}
if (i == blocks - 1 && (keylen & 63)) {
for (j = 0; j < (keylen & 63); j++) {
key[64 * (i - 1) + j] = f[j];
}
if (i == blocks - 1 && (keylen & (HMACLEN - 1))) {
memcpy(key + HMACLEN * (i - 1), f, keylen & (HMACLEN - 1));
} else {
for (j = 0; j < 64; j++) {
key[64 * (i - 1) + j] = f[j];
}
memcpy(key + HMACLEN * (i - 1), f, HMACLEN);
}
}
}