// **********************************************************************
//
// Copyright (c) 2002
// Mutable Realms, Inc.
// Huntsville, AL, USA
//
// All Rights Reserved
//
// **********************************************************************

#include <Ice/LoggerUtil.h>
#include <Ice/Network.h>
#include <Ice/LocalException.h>
#include <IceSSL/OpenSSL.h>
#include <IceSSL/SslClientTransceiver.h>
#include <IceSSL/OpenSSLPluginI.h>
#include <IceSSL/TraceLevels.h>
#include <IceSSL/OpenSSLUtils.h>
#include <IceSSL/Exception.h>
#include <IceSSL/OpenSSLJanitors.h>

using namespace std;
using namespace Ice;
using namespace IceInternal;

//
// Public Methods
//

void
IceSSL::SslClientTransceiver::write(Buffer& buf, int timeout)
{
    assert(_fd != INVALID_SOCKET);

    _plugin->registerThread();

    int totalBytesWritten = 0;
    int bytesWritten = 0;

    int packetSize = buf.b.end() - buf.i;

#ifdef _WIN32
    //
    // Limit packet size to avoid performance problems on WIN32.
    // (blatantly ripped off from Marc Laukien)
    //
    if(packetSize > 64 * 1024)
    {
        packetSize = 64 * 1024;
    }
#endif

    // We keep reading until we're done
    while(buf.i != buf.b.end())
    {
        // Ensure we're initialized.
        if(initialize(timeout) <= 0)
        {
            // Retry the initialize call
            continue;
        }

        // initialize() must have returned > 0, so we're okay to try a write.

        // Perform a select on the socket.
        if(!writeSelect(timeout))
        {
            // We're done here.
            break;
        }

        bytesWritten = sslWrite(static_cast<char*>(&*buf.i), packetSize);

        switch(getLastError())
        {
            case SSL_ERROR_NONE:
            {
                if(bytesWritten > 0)
                {
                    if(_traceLevels->network >= 3)
                    {
                        Trace out(_logger, _traceLevels->networkCat);
                        out << "sent " << bytesWritten << " of " << packetSize;
                        out << " bytes via ssl\n" << fdToString(SSL_get_fd(_sslConnection));
                    }

                    totalBytesWritten += bytesWritten;

                    buf.i += bytesWritten;

                    if(packetSize > buf.b.end() - buf.i)
                    {
                        packetSize = buf.b.end() - buf.i;
                    }
                }
                continue;
            }

            case SSL_ERROR_WANT_WRITE:
            case SSL_ERROR_WANT_READ:
            case SSL_ERROR_WANT_X509_LOOKUP:
            {
                // Perform another read.  The read should take care of this.
                continue;
            }

            case SSL_ERROR_SYSCALL:
            {
                // NOTE:  The OpenSSL demo client only raises and error condition if there were
                //        actually bytes written.  This is considered to be an error status
                //        requiring shutdown.
                //        If nothing was written, the demo client stops writing - we continue.
                //        This is potentially something wierd to watch out for.
                if(bytesWritten == -1)
                {
                    // IO Error in underlying BIO

                    if(interrupted())
                    {
                        break;
                    }

                    if(wouldBlock())
	            {
                        break;
                    }

                    if(connectionLost())
	            {
		        ConnectionLostException ex(__FILE__, __LINE__);
		        ex.error = getSocketErrno();
		        throw ex;
	            }

                    SocketException ex(__FILE__, __LINE__);
		    ex.error = getSocketErrno();
		    throw ex;
                }
                else if(bytesWritten > 0)
                {
                    ProtocolException protocolEx(__FILE__, __LINE__);

                    // Protocol Error: Unexpected EOF
                    protocolEx.message = "encountered an EOF that violates the ssl protocol\n";
                    protocolEx.message += sslGetErrors();

                    throw protocolEx;
                }
                else // bytesWritten == 0
                {
                    // Didn't write anything, continue, should be fine.
                    break;
                }
            }

            case SSL_ERROR_SSL:
            {
                ProtocolException protocolEx(__FILE__, __LINE__);

                protocolEx.message = "encountered a violation of the ssl protocol\n";
                protocolEx.message += sslGetErrors();

                throw protocolEx;
            }

            case SSL_ERROR_ZERO_RETURN:
            {
		ConnectionLostException ex(__FILE__, __LINE__);
		ex.error = getSocketErrno();
		throw ex;
            }
        }
    }
}

int
IceSSL::SslClientTransceiver::handshake(int timeout)
{
    assert(_sslConnection != 0);

    int retCode = SSL_is_init_finished(_sslConnection);

    while(!retCode)
    {
        _readTimeout = timeout > _handshakeReadTimeout ? timeout : _handshakeReadTimeout;

        if(_initWantRead)
        {
            int i = readSelect(_readTimeout);

            if(i == 0)
            {
                return 0;
            }

            _initWantRead = 0;
        }
        else if(_initWantWrite)
        {
            int i = writeSelect(timeout);

            if(i == 0)
            {
                return 0;
            }

            _initWantWrite = 0;
        }

        int result = connect();

        switch(getLastError())
        {
            case SSL_ERROR_WANT_READ:
            {
                _initWantRead = 1;
                break;
            }

            case SSL_ERROR_WANT_WRITE:
            {
                _initWantWrite = 1;
                break;
            }

            
            case SSL_ERROR_NONE:
            case SSL_ERROR_WANT_X509_LOOKUP:
            {
                // Retry connect.
                break;
            }

            case SSL_ERROR_SYSCALL:
            {
                // This is a SOCKET_ERROR, but we don't use
                // this define here as OpenSSL doesn't refer
                // to it as a SOCKET_ERROR (but that's what it is
                // if you look at their code).

                if(result == -1)
                {
                    // IO Error in underlying BIO

                    if(interrupted())
                    {
                        break;
                    }

                    if(wouldBlock())
                    {
                        readSelect(_readTimeout);
                        break;
                    }

                    if(connectionLost())
                    {
                        ConnectionLostException ex(__FILE__, __LINE__);
                        ex.error = getSocketErrno();
                        throw ex;
                    }

                    SocketException ex(__FILE__, __LINE__);
                    ex.error = getSocketErrno();
                    throw ex;
                }
                else    // result == 0
                {
                    //
                    // The OpenSSL docs say that a result code of 0 indicates
                    // a graceful shutdown. In order to cause a retry in the
                    // Ice core, we raise ConnectFailedException. However,
                    // errno isn't set in this situation, so we always use
                    // ECONNREFUSED.
                    //

                    ConnectFailedException ex(__FILE__, __LINE__);
#ifdef _WIN32
                    ex.error = WSAECONNREFUSED;
#else
                    ex.error = ECONNREFUSED;
#endif
                    throw ex;
                }
            }

            case SSL_ERROR_SSL:
            {
                int verifyError = SSL_get_verify_result(_sslConnection);

                if(verifyError != X509_V_OK && verifyError != 1)
	        {
                    CertificateVerificationException certVerEx(__FILE__, __LINE__);

                    certVerEx.message = getVerificationError(verifyError);

                    string errors = sslGetErrors();

                    if(!errors.empty())
                    {
                        certVerEx.message += "\n";
                        certVerEx.message += errors;
                    }

                    throw certVerEx;
	        }
                else
                {
                    ProtocolException protocolEx(__FILE__, __LINE__);

                    protocolEx.message = "encountered a violation of the ssl protocol during handshake\n";
                    protocolEx.message += sslGetErrors();

                    throw protocolEx;
                }
            }

            case SSL_ERROR_ZERO_RETURN:
            {
                // Indicates that that the SSL Connection has been closed.
                // But does not necessarily indicate that the underlying transport
                // has been closed (in the case of Ice, it definitely hasn't yet).

                ConnectionLostException ex(__FILE__, __LINE__);
                ex.error = getSocketErrno();
                throw ex;
            }
        }

        retCode = SSL_is_init_finished(_sslConnection);

        if(retCode > 0)
        {
            _phase = Connected;

            // Init finished, look at the connection information.
            showConnectionInfo();
        }
    }

    return retCode;
}

//
// Protected Methods
//

void
IceSSL::SslClientTransceiver::showConnectionInfo()
{
    // Only in extreme cases do we enable this, partially because it doesn't use the Logger.
    if((_traceLevels->security >= SECURITY_PROTOCOL_DEBUG) && 0)
    {
        BIOJanitor bioJanitor(BIO_new_fp(stdout, BIO_NOCLOSE));
        BIO* bio = bioJanitor.get();

        showCertificateChain(bio);

        showPeerCertificate(bio,"Client");

        showClientCAList(bio, "Client");

        showSharedCiphers(bio);

        showSelectedCipherInfo(bio);

        showHandshakeStats(bio);

        showSessionInfo(bio);
    }
}

//
// Private Methods
//

// Note: I would use a using directive of the form:
//       using IceSSL::CertificateVerifierPtr;
//       but unfortunately, it appears that this is not properly picked up.
//

IceSSL::SslClientTransceiver::SslClientTransceiver(const OpenSSLPluginIPtr& plugin,
                                                   SOCKET fd,
                                                   const CertificateVerifierPtr& certVerifier,
                                                   SSL* sslConnection) :
    SslTransceiver(plugin, fd, certVerifier, sslConnection)
{
    // Set the Connect Connection state for this connection.
    SSL_set_connect_state(_sslConnection);
}