view libtomcrypt/src/pk/rsa/rsa_encrypt_key.c @ 317:063cf9e8efea ucc-axis-hack

dropbear_log to stderr since it works now
author Matt Johnston <>
date Sat, 01 Apr 2006 12:09:46 +0000
parents 1b9e69c058d2
children 0cbe8f6dbf9e
line wrap: on
line source
/* 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, [email protected],
#include "tomcrypt.h"

  @file rsa_encrypt_key.c
  RSA PKCS OAEP encryption, Tom St Denis

#ifdef MRSA

    (PKCS #1 v2.0) OAEP pad then encrypt
    @param in          The plaintext
    @param inlen       The length of the plaintext (octets)
    @param out         [out] The ciphertext
    @param outlen      [in/out] The max size and resulting size of the ciphertext
    @param lparam      The system "lparam" for the encryption
    @param lparamlen   The length of lparam (octets)
    @param prng        An active PRNG
    @param prng_idx    The index of the desired prng
    @param hash_idx    The index of the desired hash
    @param key         The RSA key to encrypt to
    @return CRYPT_OK if successful
int rsa_encrypt_key(const unsigned char *in,     unsigned long inlen,
                          unsigned char *out,    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;
  LTC_ARGCHK(in     != NULL);
  LTC_ARGCHK(out    != NULL);
  LTC_ARGCHK(outlen != NULL);
  LTC_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) {
  /* OAEP pad the key */
  x = *outlen;
  if ((err = pkcs_1_oaep_encode(in, inlen, lparam, 
                                lparamlen, modulus_bitlen, prng, prng_idx, hash_idx, 
                                out, &x)) != CRYPT_OK) {
     return err;

  /* rsa exptmod the OAEP pad */
  return rsa_exptmod(out, x, out, outlen, PK_PUBLIC, key);

#endif /* MRSA */

/* $Source: /cvs/libtom/libtomcrypt/src/pk/rsa/rsa_encrypt_key.c,v $ */
/* $Revision: 1.3 $ */
/* $Date: 2005/05/05 14:35:59 $ */