/*
 * 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
 *
 */

#include <gnutls_int.h>

#ifdef ENABLE_SRP

#include "gnutls_errors.h"
#include "auth_srp_passwd.h"
#include "gnutls_auth.h"
#include "gnutls_auth_int.h"
#include "gnutls_srp.h"
#include "debug.h"
#include "gnutls_num.h"
#include "auth_srp.h"
#include <gnutls_str.h>
#include <auth_cert.h>
#include <gnutls_datum.h>
#include <gnutls_sig.h>
#include <auth_srp.h>
#include <gnutls_x509.h>
#include <gnutls_extra.h>

static int gen_srp_cert_server_kx(gnutls_session_t, opaque **);
static int proc_srp_cert_server_kx(gnutls_session_t, opaque *, size_t);

const mod_auth_st srp_rsa_auth_struct = {
    "SRP",
    _gnutls_gen_cert_server_certificate,
    NULL,
    gen_srp_cert_server_kx,
    _gnutls_gen_srp_client_kx,
    NULL,
    NULL,

    _gnutls_proc_cert_server_certificate,
    NULL,			/* certificate */
    proc_srp_cert_server_kx,
    _gnutls_proc_srp_client_kx,
    NULL,
    NULL
};

const mod_auth_st srp_dss_auth_struct = {
    "SRP",
    _gnutls_gen_cert_server_certificate,
    NULL,
    gen_srp_cert_server_kx,
    _gnutls_gen_srp_client_kx,
    NULL,
    NULL,

    _gnutls_proc_cert_server_certificate,
    NULL,			/* certificate */
    proc_srp_cert_server_kx,
    _gnutls_proc_srp_client_kx,
    NULL,
    NULL
};

static int gen_srp_cert_server_kx(gnutls_session_t session, opaque ** data)
{
    ssize_t ret, data_size;
    gnutls_datum_t signature, ddata;
    const gnutls_certificate_credentials_t cred;
    gnutls_cert *apr_cert_list;
    gnutls_privkey *apr_pkey;
    int apr_cert_list_length;

    ret = _gnutls_gen_srp_server_kx(session, data);

    if (ret < 0)
	return ret;

    data_size = ret;
    ddata.data = *data;
    ddata.size = data_size;

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

    /* find the appropriate certificate */
    if ((ret =
	 _gnutls_get_selected_cert(session, &apr_cert_list,
				   &apr_cert_list_length,
				   &apr_pkey)) < 0) {
	gnutls_assert();
	return ret;
    }

    if ((ret =
	 _gnutls_tls_sign_params(session, &apr_cert_list[0],
				 apr_pkey, &ddata, &signature)) < 0) {
	gnutls_assert();
	gnutls_free(*data);
	return ret;
    }

    *data = gnutls_realloc_fast(*data, data_size + signature.size + 2);
    if (*data == NULL) {
	_gnutls_free_datum(&signature);
	gnutls_assert();
	return GNUTLS_E_MEMORY_ERROR;
    }

    _gnutls_write_datum16(&(*data)[data_size], signature);
    data_size += signature.size + 2;

    _gnutls_free_datum(&signature);

    return data_size;

}

static int proc_srp_cert_server_kx(gnutls_session_t session, opaque * data,
				   size_t _data_size)
{
    ssize_t ret;
    int sigsize;
    gnutls_datum_t vparams, signature;
    ssize_t data_size;
    cert_auth_info_t info;
    gnutls_cert peer_cert;
    opaque *p;

    ret = _gnutls_proc_srp_server_kx(session, data, _data_size);
    if (ret < 0)
	return ret;

    data_size = _data_size - ret;

    info = _gnutls_get_auth_info(session);
    if (info == NULL || info->ncerts == 0) {
	gnutls_assert();
	/* we need this in order to get peer's certificate */
	return GNUTLS_E_INTERNAL_ERROR;
    }

    /* VERIFY SIGNATURE */

    vparams.size = ret;		/* all the data minus the signature */
    vparams.data = data;

    p = &data[vparams.size];

    DECR_LEN(data_size, 2);
    sigsize = _gnutls_read_uint16(p);

    DECR_LEN(data_size, sigsize);
    signature.data = &p[2];
    signature.size = sigsize;

    ret =
	_gnutls_raw_cert_to_gcert(&peer_cert,
				  session->security_parameters.cert_type,
				  &info->raw_certificate_list[0],
				  CERT_NO_COPY);

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

    ret =
	_gnutls_verify_sig_params(session,
				  &peer_cert, &vparams, &signature);

    _gnutls_gcert_deinit(&peer_cert);
    if (ret < 0) {
	gnutls_assert();
	return ret;
    }

    return 0;
}


#endif				/* ENABLE_SRP */