/***************************************************************************
 *   Copyright (C) 2005 by Christof Donat   *
 *   cdonat@gmx.de   *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program 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 General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

#include "sslclient.h"
#include "logger.h"

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

#include <boost/filesystem/operations.hpp>
#include <boost/lexical_cast.hpp>

#include <gnutls/x509.h>

using std::string;
using std::streamsize;
using boost::lexical_cast;
using boost::bad_lexical_cast;

int SSLDevice::countInstances = 0;

SSLDevice::SSLDevice(const string& address, const short int port): m_session(0) {
	this->init(address.c_str(),port);
}
SSLDevice::SSLDevice(const char* address, const short int port): m_session(0) {
	this->init(address,port);
}

void SSLDevice::init(const char* address, const short int port) {
        struct sockaddr_in addr;
        bzero(&addr,sizeof(addr));
        addr.sin_family = AF_INET;
	if( (addr.sin_addr.s_addr = inet_addr(address)) == INADDR_NONE ) {
		struct hostent* hp = gethostbyname(address);
		if( hp == 0 ) throw("can't resolve hostname '"+string(address)+"'");
		bcopy(hp->h_addr, (char*) &addr.sin_addr, hp->h_length);
	}
	addr.sin_port = htons(port);

	if( (m_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0 ) throw(string("can't open socket"));
	if( ::connect(m_socket, (struct sockaddr*) &addr, sizeof(addr)) < 0 ) {
		::close(m_socket);
		throw("can't connect to '"+string(address)+"' port "+(lexical_cast<string>(port)));
	}

	const int cert_type_priority[3] = { GNUTLS_CRT_X509, GNUTLS_CRT_OPENPGP, 0 };

	m_session = new gnutls_session;

	if( countInstances == 0 ) gnutls_global_init();
	countInstances++;

	gnutls_certificate_allocate_credentials(&m_xcred);
	gnutls_certificate_set_x509_trust_file(m_xcred, "ca.pem", GNUTLS_X509_FMT_PEM);

	gnutls_init(m_session,GNUTLS_CLIENT);

	gnutls_set_default_priority(*m_session);

	gnutls_credentials_set(*m_session, GNUTLS_CRD_CERTIFICATE, m_xcred);

	gnutls_transport_set_ptr(*m_session, (gnutls_transport_ptr)&m_socket);

	if( gnutls_handshake(*m_session) < 0 )
		throw(string(gnutls_protocol_get_name(gnutls_protocol_get_version(*m_session)))+" Handshake failed");

	verify_certificate( *m_session, address);
}
SSLDevice::SSLDevice(const SSLDevice& other) : m_session(other.m_session), m_socket(other.m_socket), m_xcred(other.m_xcred) { }
SSLDevice::~SSLDevice() { }

void SSLDevice::closeSocket() {
	gnutls_bye(*m_session, GNUTLS_SHUT_RDWR);
	gnutls_certificate_free_credentials(m_xcred);
	::close(m_socket);
	gnutls_deinit(*m_session);
	delete(m_session);

	countInstances--;
	if( countInstances == 0 ) gnutls_global_deinit();
}

streamsize SSLDevice::read(char* s, streamsize n) { return (streamsize)gnutls_record_recv(*m_session,(void*)s,(size_t)n); }
streamsize SSLDevice::write(const char* s, streamsize n) { 
	/*streamsize i = (streamsize)gnutls_record_send(*m_session,(const void*)s,(size_t)n); 
	Logger::log(Logger::DEBUG,string("sending ")+boost::lexical_cast<string>(i)+" von "+boost::lexical_cast<string>(n)+" bytes: \n---\n"+s+"\n---\n");*/
	return (streamsize)gnutls_record_send(*m_session,(const void*)s,(size_t)n); //i;
}

void SSLDevice::verify_certificate( gnutls_session session, string hostname) {
	boost::filesystem::path general("/etc/hsadminc.cert");
	if( boost::filesystem::exists(general) && !boost::filesystem::is_directory(general) )
		gnutls_certificate_set_x509_trust_file (m_xcred, general.native().c_str(), GNUTLS_X509_FMT_PEM);
	//string privfilename = getenv("HOME");
	string priv = getenv("HOME");
	boost::filesystem::path p( priv + "/.hsadmin.cert" ); 
	//p /= ".hsadminc.conf";

	if( boost::filesystem::exists(p) && !boost::filesystem::is_directory(p) )
		gnutls_certificate_set_x509_trust_file (m_xcred, p.native().c_str(), GNUTLS_X509_FMT_PEM);
	//gnutls_certificate_set_x509_trust_file (m_xcred, const char * cafile, PEM)

	unsigned int status = 0;//gnutls_certificate_verify_peers(*m_session);
	/*if( gnutls_certificate_verify_peers2(*m_session, &status) < 0 )
		throw(string("Error while verifying certificate"));*/

	string tval = "Certificate Verification failed: ";
	if( status & GNUTLS_CERT_INVALID )          { throw(tval+"The certificate is not trustet"); }
	if( status & GNUTLS_CERT_SIGNER_NOT_FOUND ) { throw(tval+"The certificate has no known Issuer"); }
	if( status & GNUTLS_CERT_REVOKED )          { throw(tval+"The certificate has been revoked"); }

	// the further checks are only valid for X509 certificates
	if ( gnutls_certificate_type_get(session) != GNUTLS_CRT_X509) return;

	const gnutls_datum* cert_list;
	unsigned int cert_list_size;
	gnutls_x509_crt cert;

	if ( gnutls_x509_crt_init(&cert) < 0) throw(tval+"error in initialization");

	cert_list = gnutls_certificate_get_peers(session, &cert_list_size);
	if ( cert_list == NULL )  throw(tval+"no certificate found");

	bool failed = false;
	string tReason = "";
	for( int i = 0; i < cert_list_size-1; i++ ) {
		bool failed = false;

		if ( gnutls_x509_crt_import( cert, &cert_list[0], GNUTLS_X509_FMT_DER) < 0)
			throw(tval+"error parsing certificate Number "+lexical_cast<string>(i));

		if ( gnutls_x509_crt_get_expiration_time(cert) < time(0) ) {
			tReason = "The certificate has expired";
			failed = true;
		}

		if ( gnutls_x509_crt_get_activation_time(cert) > time(0) ) {
			tReason = "The certificate is not yet activated";
			failed = true;
		}
		if ( !gnutls_x509_crt_check_hostname(cert,hostname.c_str()) ) {
			tReason = "The certificate’s owner does not match hostname ’";
			tReason += hostname +"'";
			failed = true;
		}
		gnutls_x509_crt_deinit(cert);

		if( !failed ) break;
	}
	if( failed ) throw(tval+tReason);
}