/* 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://libtom.org
 */
#include "tomcrypt.h"
#include <ncr-int.h>

/**
  @file rsa_export.c
  Export RSA LTC_PKCS keys, Tom St Denis
*/

#ifdef LTC_MRSA

/**
    This will export either an RSAPublicKey or RSAPrivateKey [defined in LTC_PKCS #1 v2.1] 
    @param out       [out] Destination of the packet
    @param outlen    [in/out] The max size and resulting size of the packet
    @param type      The type of exported key (PK_PRIVATE or PK_PUBLIC)
    @param key       The RSA key to export
    @return CRYPT_OK if successful
*/
int rsa_export(unsigned char *out, unsigned long *outlen, int type,
	       rsa_key * key)
{
	unsigned long zero = 0;
	int err;
	const struct algo_properties_st *algo = _ncr_algo_to_properties(NCR_ALG_RSA);
	
	LTC_ARGCHK(out != NULL);
	LTC_ARGCHK(outlen != NULL);
	LTC_ARGCHK(key != NULL);

	/* type valid? */
	if (!(key->type == PK_PRIVATE) && (type == PK_PRIVATE)) {
		return CRYPT_PK_INVALID_TYPE;
	}

	if (algo == NULL) {
		return CRYPT_INVALID_ARG;
	}

	if (type == PK_PRIVATE) {
		/* private key */
		/* output is 
		   Version, n, e, d, p, q, d mod (p-1), d mod (q - 1), 1/q mod p
		 */
		return der_encode_sequence_multi(out, outlen,
						 LTC_ASN1_SHORT_INTEGER, 1UL,
						 &zero, LTC_ASN1_INTEGER, 1UL,
						 &key->N, LTC_ASN1_INTEGER, 1UL,
						 &key->e, LTC_ASN1_INTEGER, 1UL,
						 &key->d, LTC_ASN1_INTEGER, 1UL,
						 &key->p, LTC_ASN1_INTEGER, 1UL,
						 &key->q, LTC_ASN1_INTEGER, 1UL,
						 &key->dP, LTC_ASN1_INTEGER,
						 1UL, &key->dQ,
						 LTC_ASN1_INTEGER, 1UL,
						 &key->qP, LTC_ASN1_EOL, 0UL,
						 NULL);
	} else {
		unsigned long tmplen = (mp_count_bits(&key->N) / 8) * 2 + 8;
		unsigned char *tmp = XMALLOC(tmplen);

		if (tmp == NULL) {
			return CRYPT_MEM;
		}

		err = der_encode_sequence_multi(tmp, &tmplen,
						LTC_ASN1_INTEGER, 1UL, &key->N,
						LTC_ASN1_INTEGER, 1UL, &key->e,
						LTC_ASN1_EOL, 0UL, NULL);
		if (err != CRYPT_OK) {
			goto error;
		}

		err = der_encode_subject_public_key_info(out, outlen,
							 algo, tmp, tmplen,
							 LTC_ASN1_NULL, NULL,
							 0);

error:
		XFREE(tmp);
		return err;
	}
}

#endif /* LTC_MRSA */

/* $Source: /cvs/libtom/libtomcrypt/src/pk/rsa/rsa_export.c,v $ */
/* $Revision: 1.17 $ */
/* $Date: 2007/05/12 14:32:35 $ */