/* 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@gmail.com, http://libtomcrypt.com */#include "tomcrypt.h"/**  @file rsa_encrypt_key.c  RSA PKCS #1 encryption, Tom St Denis and Andreas Lange*/#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 padding     Type of padding (LTC_PKCS_1_OAEP or LTC_PKCS_1_V1_5)    @param key         The RSA key to encrypt to    @return CRYPT_OK if successful*/int rsa_encrypt_key_ex(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, int padding, 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 padding? */  if ((padding != LTC_PKCS_1_V1_5) &&      (padding != LTC_PKCS_1_OAEP)) {    return CRYPT_PK_INVALID_PADDING;  }  /* valid prng? */  if ((err = prng_is_valid(prng_idx)) != CRYPT_OK) {     return err;  }  if (padding == LTC_PKCS_1_OAEP) {    /* valid hash? */    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) {     *outlen = modulus_bytelen;     return CRYPT_BUFFER_OVERFLOW;  }  if (padding == LTC_PKCS_1_OAEP) {    /* 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;    }  } else {    /* PKCS #1 v1.5 pad the key */    x = *outlen;    if ((err = pkcs_1_v1_5_encode(in, inlen, LTC_PKCS_1_EME,                                  modulus_bitlen, prng, prng_idx,                                  out, &x)) != CRYPT_OK) {      return err;    }  }  /* rsa exptmod the OAEP or PKCS #1 v1.5 pad */  return ltc_mp.rsa_me(out, x, out, outlen, PK_PUBLIC, key);}#endif /* MRSA *//* $Source: /cvs/libtom/libtomcrypt/src/pk/rsa/rsa_encrypt_key.c,v $ *//* $Revision: 1.8 $ *//* $Date: 2006/11/01 09:18:22 $ */