mirror of
https://github.com/Laupetin/OpenAssetTools.git
synced 2025-04-21 16:45:44 +00:00
107 lines
2.6 KiB
C
107 lines
2.6 KiB
C
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
|
|
*
|
|
* LibTomCrypt is a library that provides various cryptographic
|
|
* algorithms in a highly modular and flexible manner.
|
|
*
|
|
* The library is free for all purposes without any express
|
|
* guarantee it works.
|
|
*/
|
|
#include "tomcrypt.h"
|
|
|
|
/**
|
|
@file pkcs_1_mgf1.c
|
|
The Mask Generation Function (MGF1) for PKCS #1, Tom St Denis
|
|
*/
|
|
|
|
#ifdef LTC_PKCS_1
|
|
|
|
/**
|
|
Perform PKCS #1 MGF1 (internal)
|
|
@param hash_idx The index of the hash desired
|
|
@param seed The seed for MGF1
|
|
@param seedlen The length of the seed
|
|
@param mask [out] The destination
|
|
@param masklen The length of the mask desired
|
|
@return CRYPT_OK if successful
|
|
*/
|
|
int pkcs_1_mgf1(int hash_idx,
|
|
const unsigned char *seed, unsigned long seedlen,
|
|
unsigned char *mask, unsigned long masklen)
|
|
{
|
|
unsigned long hLen, x;
|
|
ulong32 counter;
|
|
int err;
|
|
hash_state *md;
|
|
unsigned char *buf;
|
|
|
|
LTC_ARGCHK(seed != NULL);
|
|
LTC_ARGCHK(mask != NULL);
|
|
|
|
/* ensure valid hash */
|
|
if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
|
|
return err;
|
|
}
|
|
|
|
/* get hash output size */
|
|
hLen = hash_descriptor[hash_idx].hashsize;
|
|
|
|
/* allocate memory */
|
|
md = XMALLOC(sizeof(hash_state));
|
|
buf = XMALLOC(hLen);
|
|
if (md == NULL || buf == NULL) {
|
|
if (md != NULL) {
|
|
XFREE(md);
|
|
}
|
|
if (buf != NULL) {
|
|
XFREE(buf);
|
|
}
|
|
return CRYPT_MEM;
|
|
}
|
|
|
|
/* start counter */
|
|
counter = 0;
|
|
|
|
while (masklen > 0) {
|
|
/* handle counter */
|
|
STORE32H(counter, buf);
|
|
++counter;
|
|
|
|
/* get hash of seed || counter */
|
|
if ((err = hash_descriptor[hash_idx].init(md)) != CRYPT_OK) {
|
|
goto LBL_ERR;
|
|
}
|
|
if ((err = hash_descriptor[hash_idx].process(md, seed, seedlen)) != CRYPT_OK) {
|
|
goto LBL_ERR;
|
|
}
|
|
if ((err = hash_descriptor[hash_idx].process(md, buf, 4)) != CRYPT_OK) {
|
|
goto LBL_ERR;
|
|
}
|
|
if ((err = hash_descriptor[hash_idx].done(md, buf)) != CRYPT_OK) {
|
|
goto LBL_ERR;
|
|
}
|
|
|
|
/* store it */
|
|
for (x = 0; x < hLen && masklen > 0; x++, masklen--) {
|
|
*mask++ = buf[x];
|
|
}
|
|
}
|
|
|
|
err = CRYPT_OK;
|
|
LBL_ERR:
|
|
#ifdef LTC_CLEAN_STACK
|
|
zeromem(buf, hLen);
|
|
zeromem(md, sizeof(hash_state));
|
|
#endif
|
|
|
|
XFREE(buf);
|
|
XFREE(md);
|
|
|
|
return err;
|
|
}
|
|
|
|
#endif /* LTC_PKCS_1 */
|
|
|
|
/* ref: HEAD -> master, tag: v1.18.2 */
|
|
/* git commit: 7e7eb695d581782f04b24dc444cbfde86af59853 */
|
|
/* commit time: 2018-07-01 22:49:01 +0200 */
|