go-sqlcipher/crypt_register_prng.c

43 lines
1.1 KiB
C

/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
#include "tomcrypt_private.h"
/**
@file crypt_register_prng.c
Register a PRNG, Tom St Denis
*/
/**
Register a PRNG with the descriptor table
@param prng The PRNG you wish to register
@return value >= 0 if successfully added (or already present), -1 if unsuccessful
*/
int register_prng(const struct ltc_prng_descriptor *prng)
{
int x;
LTC_ARGCHK(prng != NULL);
/* is it already registered? */
LTC_MUTEX_LOCK(&ltc_prng_mutex);
for (x = 0; x < TAB_SIZE; x++) {
if (XMEMCMP(&prng_descriptor[x], prng, sizeof(struct ltc_prng_descriptor)) == 0) {
LTC_MUTEX_UNLOCK(&ltc_prng_mutex);
return x;
}
}
/* find a blank spot */
for (x = 0; x < TAB_SIZE; x++) {
if (prng_descriptor[x].name == NULL) {
XMEMCPY(&prng_descriptor[x], prng, sizeof(struct ltc_prng_descriptor));
LTC_MUTEX_UNLOCK(&ltc_prng_mutex);
return x;
}
}
/* no spot */
LTC_MUTEX_UNLOCK(&ltc_prng_mutex);
return -1;
}