/*
 * Copyright (C) 2003-2014 Free Software Foundation, Inc.
 * Copyright (C) 2014 Red Hat
 *
 * Author: Nikos Mavrogiannopoulos
 *
 * This file is part of GnuTLS.
 *
 * The GnuTLS is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>
 *
 */

/* Functions that relate on PKCS12 Bag packet parsing.
 */

#include "gnutls_int.h"

#include <datum.h>
#include <global.h>
#include "errors.h"
#include <common.h>
#include "x509_int.h"
#include "pkcs7_int.h"

/**
 * gnutls_pkcs12_bag_init:
 * @bag: A pointer to the type to be initialized
 *
 * This function will initialize a PKCS12 bag structure. PKCS12 Bags
 * usually contain private keys, lists of X.509 Certificates and X.509
 * Certificate revocation lists.
 *
 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 *   negative error value.
 **/
int gnutls_pkcs12_bag_init(gnutls_pkcs12_bag_t * bag)
{
	*bag = gnutls_calloc(1, sizeof(gnutls_pkcs12_bag_int));

	if (*bag) {
		return 0;	/* success */
	}
	return GNUTLS_E_MEMORY_ERROR;
}

static inline void _pkcs12_bag_free_data(gnutls_pkcs12_bag_t bag)
{
	unsigned i;

	for (i = 0; i < bag->bag_elements; i++) {
		_gnutls_free_datum(&bag->element[i].data);
		_gnutls_free_datum(&bag->element[i].local_key_id);
		gnutls_free(bag->element[i].friendly_name);
		bag->element[i].type = 0;
	}

}


/**
 * gnutls_pkcs12_bag_deinit:
 * @bag: A pointer to the type to be initialized
 *
 * This function will deinitialize a PKCS12 Bag structure.
 **/
void gnutls_pkcs12_bag_deinit(gnutls_pkcs12_bag_t bag)
{
	if (!bag)
		return;

	_pkcs12_bag_free_data(bag);

	gnutls_free(bag);
}

/**
 * gnutls_pkcs12_bag_get_type:
 * @bag: The bag
 * @indx: The element of the bag to get the type
 *
 * This function will return the bag's type.
 *
 * Returns: On error a negative error value or one of the #gnutls_pkcs12_bag_type_t enumerations.
 **/
int
gnutls_pkcs12_bag_get_type(gnutls_pkcs12_bag_t bag, unsigned indx)
{
	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	if (indx >= bag->bag_elements)
		return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
	return bag->element[indx].type;
}

/**
 * gnutls_pkcs12_bag_get_count:
 * @bag: The bag
 *
 * This function will return the number of the elements within the bag.
 *
 * Returns: Number of elements in bag, or an negative error code on
 *   error.
 **/
int gnutls_pkcs12_bag_get_count(gnutls_pkcs12_bag_t bag)
{
	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	return bag->bag_elements;
}

/**
 * gnutls_pkcs12_bag_get_data:
 * @bag: The bag
 * @indx: The element of the bag to get the data from
 * @data: where the bag's data will be. Should be treated as constant.
 *
 * This function will return the bag's data. The data is a constant
 * that is stored into the bag.  Should not be accessed after the bag
 * is deleted.
 *
 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 *   negative error value.
 **/
int
gnutls_pkcs12_bag_get_data(gnutls_pkcs12_bag_t bag, unsigned indx,
			   gnutls_datum_t * data)
{
	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	if (indx >= bag->bag_elements)
		return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;

	data->data = bag->element[indx].data.data;
	data->size = bag->element[indx].data.size;

	return 0;
}

#define X509_CERT_OID "1.2.840.113549.1.9.22.1"
#define X509_CRL_OID  "1.2.840.113549.1.9.23.1"
#define RANDOM_NONCE_OID "1.2.840.113549.1.9.25.3"

int
_pkcs12_decode_crt_bag(gnutls_pkcs12_bag_type_t type,
		       const gnutls_datum_t * in, gnutls_datum_t * out)
{
	int ret;
	ASN1_TYPE c2 = ASN1_TYPE_EMPTY;

	switch (type) {
	case GNUTLS_BAG_CERTIFICATE:
		if ((ret = asn1_create_element(_gnutls_get_pkix(),
					       "PKIX1.pkcs-12-CertBag",
					       &c2)) != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret = asn1_der_decoding(&c2, in->data, in->size, NULL);
		if (ret != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret =
		    _gnutls_x509_read_string(c2, "certValue", out,
					     ASN1_ETYPE_OCTET_STRING, 1);
		if (ret < 0) {
			gnutls_assert();
			goto cleanup;
		}
		break;

	case GNUTLS_BAG_CRL:
		if ((ret = asn1_create_element(_gnutls_get_pkix(),
					       "PKIX1.pkcs-12-CRLBag",
					       &c2)) != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret = asn1_der_decoding(&c2, in->data, in->size, NULL);
		if (ret != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret =
		    _gnutls_x509_read_string(c2, "crlValue", out,
					     ASN1_ETYPE_OCTET_STRING, 1);
		if (ret < 0) {
			gnutls_assert();
			goto cleanup;
		}
		break;

	case GNUTLS_BAG_SECRET:
		if ((ret = asn1_create_element(_gnutls_get_pkix(),
					       "PKIX1.pkcs-12-SecretBag",
					       &c2)) != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret = asn1_der_decoding(&c2, in->data, in->size, NULL);
		if (ret != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret =
		    _gnutls_x509_read_string(c2, "secretValue", out,
					     ASN1_ETYPE_OCTET_STRING, 1);
		if (ret < 0) {
			gnutls_assert();
			goto cleanup;
		}
		break;

	default:
		gnutls_assert();
		asn1_delete_structure(&c2);
		return GNUTLS_E_UNIMPLEMENTED_FEATURE;
	}

	asn1_delete_structure(&c2);

	return 0;


      cleanup:

	asn1_delete_structure(&c2);
	return ret;
}


int
_pkcs12_encode_crt_bag(gnutls_pkcs12_bag_type_t type,
		       const gnutls_datum_t * raw, gnutls_datum_t * out)
{
	int ret;
	ASN1_TYPE c2 = ASN1_TYPE_EMPTY;

	switch (type) {
	case GNUTLS_BAG_CERTIFICATE:
		if ((ret = asn1_create_element(_gnutls_get_pkix(),
					       "PKIX1.pkcs-12-CertBag",
					       &c2)) != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret = asn1_write_value(c2, "certId", X509_CERT_OID, 1);
		if (ret != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret =
		    _gnutls_x509_write_string(c2, "certValue", raw,
					      ASN1_ETYPE_OCTET_STRING);
		if (ret < 0) {
			gnutls_assert();
			goto cleanup;
		}
		break;

	case GNUTLS_BAG_CRL:
		if ((ret = asn1_create_element(_gnutls_get_pkix(),
					       "PKIX1.pkcs-12-CRLBag",
					       &c2)) != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret = asn1_write_value(c2, "crlId", X509_CRL_OID, 1);
		if (ret != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret =
		    _gnutls_x509_write_string(c2, "crlValue", raw,
					      ASN1_ETYPE_OCTET_STRING);
		if (ret < 0) {
			gnutls_assert();
			goto cleanup;
		}
		break;

	case GNUTLS_BAG_SECRET:
		if ((ret = asn1_create_element(_gnutls_get_pkix(),
					       "PKIX1.pkcs-12-SecretBag",
					       &c2)) != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret =
		    asn1_write_value(c2, "secretTypeId", RANDOM_NONCE_OID,
				     1);
		if (ret != ASN1_SUCCESS) {
			gnutls_assert();
			ret = _gnutls_asn2err(ret);
			goto cleanup;
		}

		ret =
		    _gnutls_x509_write_string(c2, "secretValue", raw,
					      ASN1_ETYPE_OCTET_STRING);
		if (ret < 0) {
			gnutls_assert();
			goto cleanup;
		}
		break;

	default:
		gnutls_assert();
		asn1_delete_structure(&c2);
		return GNUTLS_E_UNIMPLEMENTED_FEATURE;
	}

	ret = _gnutls_x509_der_encode(c2, "", out, 0);

	if (ret < 0) {
		gnutls_assert();
		goto cleanup;
	}

	asn1_delete_structure(&c2);

	return 0;


      cleanup:

	asn1_delete_structure(&c2);
	return ret;
}


/**
 * gnutls_pkcs12_bag_set_data:
 * @bag: The bag
 * @type: The data's type
 * @data: the data to be copied.
 *
 * This function will insert the given data of the given type into
 * the bag.
 *
 * Returns: the index of the added bag on success, or a negative
 * value on error.
 **/
int
gnutls_pkcs12_bag_set_data(gnutls_pkcs12_bag_t bag,
			   gnutls_pkcs12_bag_type_t type,
			   const gnutls_datum_t * data)
{
	int ret;
	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	if (bag->bag_elements == MAX_BAG_ELEMENTS - 1) {
		gnutls_assert();
		/* bag is full */
		return GNUTLS_E_MEMORY_ERROR;
	}

	if (bag->bag_elements == 1) {
		/* A bag with a key or an encrypted bag, must have
		 * only one element.
		 */

		if (bag->element[0].type == GNUTLS_BAG_PKCS8_KEY ||
		    bag->element[0].type == GNUTLS_BAG_PKCS8_ENCRYPTED_KEY
		    || bag->element[0].type == GNUTLS_BAG_ENCRYPTED) {
			gnutls_assert();
			return GNUTLS_E_INVALID_REQUEST;
		}
	}

	ret =
	    _gnutls_set_datum(&bag->element[bag->bag_elements].data,
			      data->data, data->size);

	if (ret < 0) {
		gnutls_assert();
		return ret;
	}

	bag->element[bag->bag_elements].type = type;

	bag->bag_elements++;

	return bag->bag_elements - 1;
}

/**
 * gnutls_pkcs12_bag_set_crt:
 * @bag: The bag
 * @crt: the certificate to be copied.
 *
 * This function will insert the given certificate into the
 * bag. This is just a wrapper over gnutls_pkcs12_bag_set_data().
 *
 * Returns: the index of the added bag on success, or a negative
 * value on failure.
 **/
int
gnutls_pkcs12_bag_set_crt(gnutls_pkcs12_bag_t bag, gnutls_x509_crt_t crt)
{
	int ret;
	gnutls_datum_t data;

	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	ret = _gnutls_x509_der_encode(crt->cert, "", &data, 0);
	if (ret < 0) {
		gnutls_assert();
		return ret;
	}

	ret =
	    gnutls_pkcs12_bag_set_data(bag, GNUTLS_BAG_CERTIFICATE, &data);

	_gnutls_free_datum(&data);

	return ret;
}

/**
 * gnutls_pkcs12_bag_set_crl:
 * @bag: The bag
 * @crl: the CRL to be copied.
 *
 * This function will insert the given CRL into the
 * bag. This is just a wrapper over gnutls_pkcs12_bag_set_data().
 *
 * Returns: the index of the added bag on success, or a negative error code
 * on failure.
 **/
int
gnutls_pkcs12_bag_set_crl(gnutls_pkcs12_bag_t bag, gnutls_x509_crl_t crl)
{
	int ret;
	gnutls_datum_t data;


	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	ret = _gnutls_x509_der_encode(crl->crl, "", &data, 0);
	if (ret < 0) {
		gnutls_assert();
		return ret;
	}

	ret = gnutls_pkcs12_bag_set_data(bag, GNUTLS_BAG_CRL, &data);

	_gnutls_free_datum(&data);

	return ret;
}

/**
 * gnutls_pkcs12_bag_set_key_id:
 * @bag: The bag
 * @indx: The bag's element to add the id
 * @id: the ID
 *
 * This function will add the given key ID, to the specified, by the
 * index, bag element. The key ID will be encoded as a 'Local key
 * identifier' bag attribute, which is usually used to distinguish
 * the local private key and the certificate pair.
 *
 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 *   negative error value. or a negative error code on error.
 **/
int
gnutls_pkcs12_bag_set_key_id(gnutls_pkcs12_bag_t bag, unsigned indx,
			     const gnutls_datum_t * id)
{
	int ret;


	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	if (indx > bag->bag_elements - 1) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	ret = _gnutls_set_datum(&bag->element[indx].local_key_id,
				id->data, id->size);

	if (ret < 0) {
		gnutls_assert();
		return ret;
	}

	return 0;
}

/**
 * gnutls_pkcs12_bag_get_key_id:
 * @bag: The bag
 * @indx: The bag's element to add the id
 * @id: where the ID will be copied (to be treated as const)
 *
 * This function will return the key ID, of the specified bag element.
 * The key ID is usually used to distinguish the local private key and
 * the certificate pair.
 *
 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 *   negative error value. or a negative error code on error.
 **/
int
gnutls_pkcs12_bag_get_key_id(gnutls_pkcs12_bag_t bag, unsigned indx,
			     gnutls_datum_t * id)
{
	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	if (indx > bag->bag_elements - 1) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	id->data = bag->element[indx].local_key_id.data;
	id->size = bag->element[indx].local_key_id.size;

	return 0;
}

/**
 * gnutls_pkcs12_bag_get_friendly_name:
 * @bag: The bag
 * @indx: The bag's element to add the id
 * @name: will hold a pointer to the name (to be treated as const)
 *
 * This function will return the friendly name, of the specified bag
 * element.  The key ID is usually used to distinguish the local
 * private key and the certificate pair.
 *
 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 *   negative error value. or a negative error code on error.
 **/
int
gnutls_pkcs12_bag_get_friendly_name(gnutls_pkcs12_bag_t bag, unsigned indx,
				    char **name)
{
	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	if (indx > bag->bag_elements - 1) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	*name = bag->element[indx].friendly_name;

	return 0;
}


/**
 * gnutls_pkcs12_bag_set_friendly_name:
 * @bag: The bag
 * @indx: The bag's element to add the id
 * @name: the name
 *
 * This function will add the given key friendly name, to the
 * specified, by the index, bag element. The name will be encoded as
 * a 'Friendly name' bag attribute, which is usually used to set a
 * user name to the local private key and the certificate pair.
 *
 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 *   negative error value. or a negative error code on error.
 **/
int
gnutls_pkcs12_bag_set_friendly_name(gnutls_pkcs12_bag_t bag, unsigned indx,
				    const char *name)
{
	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	if (indx > bag->bag_elements - 1) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	bag->element[indx].friendly_name = gnutls_strdup(name);

	if (name == NULL) {
		gnutls_assert();
		return GNUTLS_E_MEMORY_ERROR;
	}

	return 0;
}


/**
 * gnutls_pkcs12_bag_decrypt:
 * @bag: The bag
 * @pass: The password used for encryption, must be ASCII.
 *
 * This function will decrypt the given encrypted bag and return 0 on
 * success.
 *
 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned,
 *   otherwise a negative error code is returned.
 **/
int gnutls_pkcs12_bag_decrypt(gnutls_pkcs12_bag_t bag, const char *pass)
{
	int ret;
	gnutls_datum_t dec;

	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	if (bag->element[0].type != GNUTLS_BAG_ENCRYPTED) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	ret =
	    _gnutls_pkcs7_decrypt_data(&bag->element[0].data, pass, &dec);

	if (ret < 0) {
		gnutls_assert();
		return ret;
	}

	/* decryption succeeded. Now decode the SafeContents
	 * stuff, and parse it.
	 */

	_gnutls_free_datum(&bag->element[0].data);

	ret = _pkcs12_decode_safe_contents(&dec, bag);

	_gnutls_free_datum(&dec);

	if (ret < 0) {
		gnutls_assert();
		return ret;
	}

	return 0;
}

/**
 * gnutls_pkcs12_bag_encrypt:
 * @bag: The bag
 * @pass: The password used for encryption, must be ASCII
 * @flags: should be one of #gnutls_pkcs_encrypt_flags_t elements bitwise or'd
 *
 * This function will encrypt the given bag.
 *
 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned,
 *   otherwise a negative error code is returned.
 **/
int
gnutls_pkcs12_bag_encrypt(gnutls_pkcs12_bag_t bag, const char *pass,
			  unsigned int flags)
{
	int ret;
	ASN1_TYPE safe_cont = ASN1_TYPE_EMPTY;
	gnutls_datum_t der = { NULL, 0 };
	gnutls_datum_t enc = { NULL, 0 };
	schema_id id;

	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	if (bag->element[0].type == GNUTLS_BAG_ENCRYPTED) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	/* Encode the whole bag to a safe contents
	 * structure.
	 */
	ret = _pkcs12_encode_safe_contents(bag, &safe_cont, NULL);
	if (ret < 0) {
		gnutls_assert();
		return ret;
	}

	/* DER encode the SafeContents.
	 */
	ret = _gnutls_x509_der_encode(safe_cont, "", &der, 0);

	asn1_delete_structure(&safe_cont);

	if (ret < 0) {
		gnutls_assert();
		return ret;
	}

	if (flags & GNUTLS_PKCS_PLAIN) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	id = _gnutls_pkcs_flags_to_schema(flags);

	/* Now encrypt them.
	 */
	ret = _gnutls_pkcs7_encrypt_data(id, &der, pass, &enc);

	_gnutls_free_datum(&der);

	if (ret < 0) {
		gnutls_assert();
		return ret;
	}

	/* encryption succeeded. 
	 */

	_pkcs12_bag_free_data(bag);

	bag->element[0].type = GNUTLS_BAG_ENCRYPTED;
	bag->element[0].data = enc;

	bag->bag_elements = 1;


	return 0;
}

/**
 * gnutls_pkcs12_bag_enc_info:
 * @bag: The bag
 * @schema: indicate the schema as one of %gnutls_pkcs_encrypt_flags_t
 * @cipher: the cipher used as %gnutls_cipher_algorithm_t
 * @salt: PBKDF2 salt (if non-NULL then @salt_size initially holds its size)
 * @salt_size: PBKDF2 salt size
 * @iter_count: PBKDF2 iteration count
 * @oid: if non-NULL it will contain an allocated null-terminated variable with the OID
 *
 * This function will provide information on the encryption algorithms used
 * in an encrypted bag. If the structure algorithms
 * are unknown the code %GNUTLS_E_UNKNOWN_CIPHER_TYPE will be returned,
 * and only @oid, will be set. That is, @oid will be set on encrypted bags
 * whether supported or not. It must be deinitialized using gnutls_free().
 * The other variables are only set on supported structures.
 *
 * Returns: %GNUTLS_E_INVALID_REQUEST if the provided bag isn't encrypted,
 *  %GNUTLS_E_UNKNOWN_CIPHER_TYPE if the structure's encryption isn't supported, or
 *  another negative error code in case of a failure. Zero on success.
 **/
int
gnutls_pkcs12_bag_enc_info(gnutls_pkcs12_bag_t bag, unsigned int *schema, unsigned int *cipher,
	void *salt, unsigned int *salt_size, unsigned int *iter_count, char **oid)
{
	int ret;
	struct pbkdf2_params kdf;
	const struct pkcs_cipher_schema_st *p;

	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	if (bag->element[0].type != GNUTLS_BAG_ENCRYPTED) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	ret =
	    _gnutls_pkcs7_data_enc_info(&bag->element[0].data, &p, &kdf, oid);

	if (ret < 0) {
		gnutls_assert();
		return ret;
	}

	if (schema)
		*schema = p->flag;

	if (cipher)
		*cipher = p->cipher;

	if (iter_count)
		 *iter_count = kdf.iter_count;

	if (salt) {
		if (*salt_size >= (unsigned)kdf.salt_size) {
			memcpy(salt, kdf.salt, kdf.salt_size);
		} else {
			*salt_size = kdf.salt_size;
			return gnutls_assert_val(GNUTLS_E_SHORT_MEMORY_BUFFER);
		}
	}

	if (salt_size)
		*salt_size = kdf.salt_size;


	return 0;
}

/**
 * gnutls_pkcs12_bag_set_privkey:
 * @bag: The bag
 * @privkey: the private key to be copied.
 * @password: the password to protect the key with (may be %NULL)
 * @flags: should be one of #gnutls_pkcs_encrypt_flags_t elements bitwise or'd
 *
 * This function will insert the given private key into the
 * bag. This is just a wrapper over gnutls_pkcs12_bag_set_data().
 *
 * Returns: the index of the added bag on success, or a negative
 * value on failure.
 **/
int
gnutls_pkcs12_bag_set_privkey(gnutls_pkcs12_bag_t bag, gnutls_x509_privkey_t privkey,
			      const char *password, unsigned flags)
{
	int ret;
	gnutls_datum_t data = {NULL, 0};

	if (bag == NULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	ret = gnutls_x509_privkey_export2_pkcs8(privkey, GNUTLS_X509_FMT_DER,
						password, flags, &data);
	if (ret < 0)
		return gnutls_assert_val(ret);

	if (password == NULL) {
		ret = gnutls_pkcs12_bag_set_data(bag, GNUTLS_BAG_PKCS8_KEY, &data);
		if (ret < 0) {
			gnutls_assert();
			goto cleanup;
		}
	} else {
		ret = gnutls_pkcs12_bag_set_data(bag, GNUTLS_BAG_PKCS8_ENCRYPTED_KEY, &data);
		if (ret < 0) {
			gnutls_assert();
			goto cleanup;
		}
	}

 cleanup:
	_gnutls_free_datum(&data);

	return ret;
}