/*
 * Copyright (C) 2001,2002,2003 Nikos Mavroyanopoulos
 * Copyright (C) 2004 Free Software Foundation
 *
 * This file is part of GNUTLS.
 *
 *  The GNUTLS library 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 library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
 *
 */

/* This file was intended to contains functions to be exported in the
 * API and did not fit elsewhere.
 */

#include <gnutls_int.h>
#include <auth_srp.h>
#include <auth_anon.h>
#include <auth_cert.h>
#include <gnutls_errors.h>
#include <gnutls_auth_int.h>
#include <gnutls_state.h>

/* ANON & DHE */

/**
  * gnutls_dh_set_prime_bits - Used to set the bits for a DH ciphersuite
  * @session: is a &gnutls_session structure.
  * @bits: is the number of bits
  *
  * This function sets the number of bits, for use in an 
  * Diffie Hellman key exchange. This is used both in DH ephemeral and
  * DH anonymous cipher suites. This will set the
  * minimum size of the prime that will be used for the handshake.
  *
  * In the client side it sets the minimum accepted number of bits.
  * If a server sends a prime with less bits than that 
  * GNUTLS_E_DH_PRIME_UNACCEPTABLE will be returned by the
  * handshake.
  *
  **/
void gnutls_dh_set_prime_bits(gnutls_session session, unsigned int bits)
{
	session->internals.dh_prime_bits = bits;
}

/**
  * gnutls_dh_get_prime_bits - This function returns the bits used in DH authentication
  * @session: is a gnutls session
  *
  * This function will return the bits of the prime used in the last Diffie Hellman authentication
  * with the peer. Should be used for both anonymous and ephemeral diffie Hellman.
  * Returns a negative value in case of an error.
  *
  **/
int gnutls_dh_get_prime_bits(gnutls_session session)
{
	switch( gnutls_auth_get_type( session)) {
		case GNUTLS_CRD_ANON: {
			ANON_SERVER_AUTH_INFO info;

			info = _gnutls_get_auth_info(session);
			if (info == NULL)
				return GNUTLS_E_INTERNAL_ERROR;
			return info->dh_prime_bits;
		}
		case GNUTLS_CRD_CERTIFICATE: {
			CERTIFICATE_AUTH_INFO info;

			info = _gnutls_get_auth_info(session);
			if (info == NULL)
				return GNUTLS_E_INTERNAL_ERROR;

			return info->dh_prime_bits;
		}
		default:
			gnutls_assert();
			return GNUTLS_E_INVALID_REQUEST;
	}
}

/**
  * gnutls_dh_get_secret_bits - This function returns the bits used in DH authentication
  * @session: is a gnutls session
  *
  * This function will return the bits used in the last Diffie Hellman authentication
  * with the peer. Should be used for both anonymous and ephemeral diffie Hellman.
  * Returns a negative value in case of an error.
  *
  **/
int gnutls_dh_get_secret_bits(gnutls_session session)
{
	switch( gnutls_auth_get_type( session)) {
		case GNUTLS_CRD_ANON: {
			ANON_SERVER_AUTH_INFO info;

			info = _gnutls_get_auth_info(session);
			if (info == NULL)
				return GNUTLS_E_INTERNAL_ERROR;
			return info->dh_secret_bits;
		}
		case GNUTLS_CRD_CERTIFICATE: {
			CERTIFICATE_AUTH_INFO info;

			info = _gnutls_get_auth_info(session);
			if (info == NULL)
				return GNUTLS_E_INTERNAL_ERROR;

			return info->dh_secret_bits;
		}
		default:
			gnutls_assert();
			return GNUTLS_E_INVALID_REQUEST;
	}
}


/**
  * gnutls_rsa_export_get_modulus_bits - This function returns the bits used in RSA-export key exchange
  * @session: is a gnutls session
  *
  * This function will return the bits used in the last RSA-EXPORT key exchange
  * with the peer. 
  * Returns a negative value in case of an error.
  *
  **/
int gnutls_rsa_export_get_modulus_bits(gnutls_session session)
{
CERTIFICATE_AUTH_INFO info;

	info = _gnutls_get_auth_info(session);
	if (info == NULL)
		return GNUTLS_E_INTERNAL_ERROR;

	return info->rsa_export_modulus_bits;
}

/**
  * gnutls_dh_get_peers_public_bits - This function returns the bits used in DH authentication
  * @session: is a gnutls session
  *
  * This function will return the bits used in the last Diffie Hellman authentication
  * with the peer. Should be used for both anonymous and ephemeral diffie Hellman.
  * Returns a negative value in case of an error.
  *
  **/
int gnutls_dh_get_peers_public_bits(gnutls_session session)
{
	switch( gnutls_auth_get_type( session)) {
		case GNUTLS_CRD_ANON: {
			ANON_SERVER_AUTH_INFO info;

			info = _gnutls_get_auth_info(session);
			if (info == NULL)
				return GNUTLS_E_INTERNAL_ERROR;
			return info->dh_peer_public_bits;
		}
		case GNUTLS_CRD_CERTIFICATE: {
			CERTIFICATE_AUTH_INFO info;

			info = _gnutls_get_auth_info(session);
			if (info == NULL)
				return GNUTLS_E_INTERNAL_ERROR;

			return info->dh_peer_public_bits;
		}
		default:
			gnutls_assert();
			return GNUTLS_E_INVALID_REQUEST;
	}
}

/* CERTIFICATE STUFF */

/**
  * gnutls_certificate_get_ours - This function returns the raw certificate sent in the last handshake
  * @session: is a gnutls session
  *
  * This function will return the certificate as sent to the peer,
  * in the last handshake. These certificates are in raw format. 
  * In X.509 this is a certificate list. In OpenPGP this is a single
  * certificate.
  * Returns NULL in case of an error, or if no certificate was used.
  *
  **/
const gnutls_datum *gnutls_certificate_get_ours(gnutls_session session)
{
	const gnutls_certificate_credentials cred;

	CHECK_AUTH(GNUTLS_CRD_CERTIFICATE, NULL);

	cred = _gnutls_get_cred(session->key, GNUTLS_CRD_CERTIFICATE, NULL);
	if (cred == NULL || cred->cert_list == NULL) {
		gnutls_assert();
		return NULL;
	}

	if (session->internals.selected_cert_list == NULL)
		return NULL;

	return &session->internals.selected_cert_list[0].raw;
}

/**
  * gnutls_certificate_get_peers - This function returns the peer's raw certificate
  * @session: is a gnutls session
  * @list_size: is the length of the certificate list
  *
  * This function will return the peer's raw certificate (list) as 
  * sent by the peer.
  * These certificates are in raw format (DER encoded for X.509). 
  * In case of a X.509 then a certificate list may be present. 
  * The first certificate in the list is the peer's certificate,
  * following the issuer's certificate, then the issuer's issuer etc.
  * Returns NULL in case of an error, or if no certificate was sent.
  *
  **/
const gnutls_datum *gnutls_certificate_get_peers(gnutls_session session, 
	unsigned int *list_size)
{
	CERTIFICATE_AUTH_INFO info;

	CHECK_AUTH(GNUTLS_CRD_CERTIFICATE, NULL);

	info = _gnutls_get_auth_info(session);
	if (info == NULL)
		return NULL;

	*list_size = info->ncerts;
	return info->raw_certificate_list;
}


/**
  * gnutls_certificate_client_get_request_status - This function returns the certificate request status
  * @session: is a gnutls session
  *
  * This function will return 0 if the peer (server) did not request client
  * authentication or 1 otherwise.
  * Returns a negative value in case of an error.
  *
  **/
int gnutls_certificate_client_get_request_status(gnutls_session session)
{
	CERTIFICATE_AUTH_INFO info;

	CHECK_AUTH(GNUTLS_CRD_CERTIFICATE, 0);

	info = _gnutls_get_auth_info(session);
	if (info == NULL)
		return GNUTLS_E_INTERNAL_ERROR;
	return info->certificate_requested;
}

/**
  * gnutls_fingerprint - This function calculates the fingerprint of the given data
  * @algo: is a digest algorithm
  * @data: is the data
  * @result: is the place where the result will be copied (may be null). 
  * @result_size: should hold the size of the result. The actual size
  * of the returned result will also be copied there.
  *
  * This function will calculate a fingerprint (actually a hash), of the
  * given data. The result is not printable data. You should convert it
  * to hex, or to something else printable.
  *
  * This is the usual way to calculate a fingerprint of an X.509 
  * DER encoded certificate. Note however that the fingerprint 
  * of an OpenPGP is not just a hash and cannot be calculated with
  * this function.
  *
  * Returns a negative value in case of an error.
  *
  **/
int gnutls_fingerprint(gnutls_digest_algorithm algo, const gnutls_datum* data, 
	void* result, size_t* result_size)
{
	GNUTLS_HASH_HANDLE td;
	int hash_len = _gnutls_hash_get_algo_len(algo);
	
	if (hash_len < 0 || (uint)hash_len > *result_size ||
		result==NULL) 
	{
		*result_size = hash_len;
		return GNUTLS_E_SHORT_MEMORY_BUFFER;
	}
	*result_size = hash_len;

	if (result) {
		td = _gnutls_hash_init( algo);
		if (td==NULL) return GNUTLS_E_HASH_FAILED;
	
		_gnutls_hash( td, data->data, data->size);
	
		_gnutls_hash_deinit( td, result);
	}
		
	return 0;
}

/**
  * gnutls_anon_set_server_dh_params - This function will set the DH parameters for a server to use
  * @res: is a gnutls_anon_server_credentials structure
  * @dh_params: is a structure that holds diffie hellman parameters.
  *
  * This function will set the diffie hellman parameters for an anonymous
  * server to use. These parameters will be used in Anonymous Diffie Hellman 
  * cipher suites.
  *
  **/
void gnutls_anon_set_server_dh_params( gnutls_anon_server_credentials res, gnutls_dh_params dh_params)
{
	res->dh_params = dh_params;
}

/**
  * gnutls_certificate_set_dh_params - This function will set the DH parameters for a server to use
  * @res: is a gnutls_certificate_credentials structure
  * @dh_params: is a structure that holds diffie hellman parameters.
  *
  * This function will set the diffie hellman parameters for a certificate
  * server to use. These parameters will be used in Ephemeral Diffie Hellman 
  * cipher suites.
  *
  **/
void gnutls_certificate_set_dh_params(gnutls_certificate_credentials res, gnutls_dh_params dh_params)
{
	res->dh_params = dh_params;
}

/**
  * gnutls_certificate_set_params_function - This function will set the DH or RSA parameters callback
  * @res: is a gnutls_certificate_credentials structure
  * @func: is the function to be called
  *
  * This function will set a callback in order for the server to get the 
  * diffie hellman or RSA parameters for certificate authentication. The callback
  * should return zero on success.
  *
  **/
void gnutls_certificate_set_params_function(gnutls_certificate_credentials res, 
	gnutls_params_function* func)
{
	res->params_func = func;
}

/**
  * gnutls_anon_set_params_function - This function will set the DH parameters callback
  * @res: is a gnutls_certificate_credentials structure
  * @func: is the function to be called
  *
  * This function will set a callback in order for the server to get the 
  * diffie hellman parameters for anonymous authentication. The callback should
  * return zero on success.
  *
  **/
void gnutls_anon_set_params_function(gnutls_anon_server_credentials res, 
	gnutls_params_function* func)
{
	res->params_func = func;
}


/**
  * gnutls_certificate_set_verify_flags - This function will set the flags to be used at certificate verification
  * @res: is a gnutls_certificate_credentials structure
  * @flags: are the flagsis a structure that holds diffie hellman parameters.
  *
  * This function will set the flags to be used at verification of the certificates.
  * Flags must be OR of the gnutls_certificate_verify_flags enumerations.
  *
  **/
void gnutls_certificate_set_verify_flags(gnutls_certificate_credentials res, unsigned int flags) 
{
	res->verify_flags = flags;
}

/**
  * gnutls_certificate_set_rsa_export_params - This function will set the RSA parameters for a server to use
  * @res: is a gnutls_certificate_credentials structure
  * @rsa_params: is a structure that holds temporary RSA parameters.
  *
  * This function will set the temporary RSA parameters for a certificate
  * server to use. These parameters will be used in RSA-EXPORT
  * cipher suites.
  *
  **/
void gnutls_certificate_set_rsa_export_params(gnutls_certificate_credentials res, gnutls_rsa_params rsa_params) 
{
	res->rsa_params = rsa_params;
}