/* 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. * * Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org */#include <mycrypt.h>/* PKCS #5, Algorithm #1 */#ifdef PKCS_5int pkcs_5_alg1(const unsigned char *password, unsigned long password_len,                 const unsigned char *salt,                 int iteration_count,  int hash_idx,                unsigned char *out,   unsigned long *outlen){   int err;   unsigned long x;   hash_state md;   unsigned char buf[MAXBLOCKSIZE];   _ARGCHK(password != NULL);   _ARGCHK(salt     != NULL);   _ARGCHK(out      != NULL);   _ARGCHK(outlen   != NULL);   /* test hash IDX */   if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {      return err;   }   /* hash initial password + salt */   hash_descriptor[hash_idx].init(&md);   hash_descriptor[hash_idx].process(&md, password, password_len);   hash_descriptor[hash_idx].process(&md, salt, 8);   hash_descriptor[hash_idx].done(&md, buf);   while (--iteration_count) {      // code goes here.      x = sizeof(buf);      if ((err = hash_memory(hash_idx, buf, hash_descriptor[hash_idx].hashsize, buf, &x)) != CRYPT_OK) {         return err;      }   }   /* copy upto outlen bytes */   for (x = 0; x < hash_descriptor[hash_idx].hashsize && x < *outlen; x++) {       out[x] = buf[x];   }   *outlen = x;#ifdef CLEAN_STACK    zeromem(buf, sizeof(buf));#endif   return CRYPT_OK;}#endif