/* 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"#ifdef MRSA/* OAEP pad then encrypt */int rsa_encrypt_key(const unsigned char *inkey,  unsigned long inlen,                          unsigned char *outkey, unsigned long *outlen,                    const unsigned char *lparam, unsigned long lparamlen,                    prng_state *prng, int prng_idx, int hash_idx, rsa_key *key){  unsigned long modulus_bitlen, modulus_bytelen, x;  int           err;    _ARGCHK(inkey  != NULL);  _ARGCHK(outkey != NULL);  _ARGCHK(outlen != NULL);  _ARGCHK(key    != NULL);    /* valid prng and hash ? */  if ((err = prng_is_valid(prng_idx)) != CRYPT_OK) {     return err;  }  if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {     return err;  }    /* get modulus len in bits */  modulus_bitlen = mp_count_bits(&(key->N));  /* outlen must be at least the size of the modulus */  modulus_bytelen = mp_unsigned_bin_size(&(key->N));  if (modulus_bytelen > *outlen) {     return CRYPT_BUFFER_OVERFLOW;  }        /* OAEP pad the key */  x = *outlen;  if ((err = pkcs_1_oaep_encode(inkey, inlen, lparam,                                 lparamlen, modulus_bitlen, prng, prng_idx, hash_idx,                                 outkey, &x)) != CRYPT_OK) {     return err;  }                                  /* rsa exptmod the OAEP pad */  return rsa_exptmod(outkey, x, outkey, outlen, PK_PUBLIC, prng, prng_idx, key);}#endif /* MRSA */