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      1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
      2  *
      3  * LibTomCrypt is a library that provides various cryptographic
      4  * algorithms in a highly modular and flexible manner.
      5  *
      6  * The library is free for all purposes without any express
      7  * guarantee it works.
      8  *
      9  * Tom St Denis, tomstdenis (at) gmail.com, http://libtomcrypt.com
     10  */
     11 #include "tomcrypt.h"
     12 
     13 /**
     14   @file crypt_register_prng.c
     15   Register a PRNG, Tom St Denis
     16 */
     17 
     18 /**
     19    Register a PRNG with the descriptor table
     20    @param prng   The PRNG you wish to register
     21    @return value >= 0 if successfully added (or already present), -1 if unsuccessful
     22 */
     23 int register_prng(const struct ltc_prng_descriptor *prng)
     24 {
     25    int x;
     26 
     27    LTC_ARGCHK(prng != NULL);
     28 
     29    /* is it already registered? */
     30    LTC_MUTEX_LOCK(&ltc_prng_mutex);
     31    for (x = 0; x < TAB_SIZE; x++) {
     32        if (XMEMCMP(&prng_descriptor[x], prng, sizeof(struct ltc_prng_descriptor)) == 0) {
     33           LTC_MUTEX_UNLOCK(&ltc_prng_mutex);
     34           return x;
     35        }
     36    }
     37 
     38    /* find a blank spot */
     39    for (x = 0; x < TAB_SIZE; x++) {
     40        if (prng_descriptor[x].name == NULL) {
     41           XMEMCPY(&prng_descriptor[x], prng, sizeof(struct ltc_prng_descriptor));
     42           LTC_MUTEX_UNLOCK(&ltc_prng_mutex);
     43           return x;
     44        }
     45    }
     46 
     47    /* no spot */
     48    LTC_MUTEX_UNLOCK(&ltc_prng_mutex);
     49    return -1;
     50 }
     51 
     52 /* $Source: /cvs/libtom/libtomcrypt/src/misc/crypt/crypt_register_prng.c,v $ */
     53 /* $Revision: 1.7 $ */
     54 /* $Date: 2006/11/01 09:28:17 $ */
     55