text: /* 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 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;
  }
  
  /* ref:         tag: v1.18.2, master */
  /* git commit:  7e7eb695d581782f04b24dc444cbfde86af59853 */
  /* commit time: 2018-07-01 22:49:01 +0200 */
  