}

    if (model != NULL) {
	int mode;
	/* Get the "model" context */
	chan = Tcl_GetChannel(interp, model, &mode);
	if (chan == (Tcl_Channel) NULL) {
	    Tls_Free((char *) statePtr);
	    Tls_Free(statePtr);
	    return TCL_ERROR;
	}

        /*
         * Make sure to operate on the topmost channel
         */
        chan = Tcl_GetTopChannel(chan);
	if (Tcl_GetChannelType(chan) != Tls_ChannelType()) {
	    Tcl_AppendResult(interp, "bad channel \"",
		    Tcl_GetChannelName(chan), "\": not a TLS channel", NULL);
	    Tls_Free((char *) statePtr);
	    Tls_Free(statePtr);
	    return TCL_ERROR;
	}
	ctx = ((State *)Tcl_GetChannelInstanceData(chan))->ctx;
    } else {
	if ((ctx = CTX_Init(statePtr, server, proto, keyfile, certfile, key,
    cert, key_len, cert_len, CAdir, CAfile, ciphers,
    DHparams)) == (SSL_CTX*)0) {
	    Tls_Free((char *) statePtr);
	    Tls_Free(statePtr);
	    return TCL_ERROR;
	}
    }

    statePtr->ctx = ctx;

    /*

    dprintf("Consuming Tcl channel %s", Tcl_GetChannelName(chan));
    statePtr->self = Tcl_StackChannel(interp, Tls_ChannelType(), statePtr, (TCL_READABLE | TCL_WRITABLE), chan);
    dprintf("Created channel named %s", Tcl_GetChannelName(statePtr->self));
    if (statePtr->self == (Tcl_Channel) NULL) {
	/*
	 * No use of Tcl_EventuallyFree because no possible Tcl_Preserve.
	 */
	Tls_Free((char *) statePtr);
	Tls_Free(statePtr);
	return TCL_ERROR;
    }

    Tcl_SetChannelOption(interp, statePtr->self, "-translation", Tcl_DStringValue(&upperChannelTranslation));
    Tcl_SetChannelOption(interp, statePtr->self, "-encoding", Tcl_DStringValue(&upperChannelEncoding));
    Tcl_SetChannelOption(interp, statePtr->self, "-eofchar", Tcl_DStringValue(&upperChannelEOFChar));
    Tcl_SetChannelOption(interp, statePtr->self, "-blocking", Tcl_DStringValue(&upperChannelBlocking));

    /*
     * SSL Initialization
     */

    statePtr->ssl = SSL_new(statePtr->ctx);
    if (!statePtr->ssl) {
	/* SSL library error */
	Tcl_AppendResult(interp, "couldn't construct ssl session: ", REASON(),
		(char *) NULL);
	Tls_Free((char *) statePtr);
	Tls_Free(statePtr);
	return TCL_ERROR;
    }

#ifndef OPENSSL_NO_TLSEXT
    if (servername) {
        if (!SSL_set_tlsext_host_name(statePtr->ssl, servername) && require) {
            Tcl_AppendResult(interp, "setting TLS host name extension failed",
                (char *) NULL);
            Tls_Free((char *) statePtr);
            Tls_Free(statePtr);
            return TCL_ERROR;
        }
    }
#endif

    /*
     * SSL Callbacks

 *
 * Side effects:
 *	Frees all the state
 *
 *-------------------------------------------------------------------
 */
void
Tls_Free( char *blockPtr )
Tls_Free( void *blockPtr )
{
    State *statePtr = (State *)blockPtr;

    dprintf("Called");

    Tls_Clean(statePtr);
    ckfree(blockPtr);

 *	0 if successful, the value of Tcl_GetErrno() if failed.
 *
 * Side effects:
 *	Closes the socket of the channel.
 *
 *-------------------------------------------------------------------
 */
static int TlsCloseProc(ClientData instanceData, Tcl_Interp *interp) {
static int TlsCloseProc(ClientData instanceData, TCL_UNUSED(Tcl_Interp *)) {
	State *statePtr = (State *) instanceData;

	dprintf("TlsCloseProc(%p)", (void *) statePtr);
	dprintf("TlsCloseProc(%p)", statePtr);

	Tls_Clean(statePtr);
	Tcl_EventuallyFree((ClientData)statePtr, Tls_Free);
	Tcl_EventuallyFree(statePtr, Tls_Free);

	dprintf("Returning TCL_OK");

	return(TCL_OK);

	/* Interp is unused. */
	interp = interp;
}

/*
 *------------------------------------------------------*
 *
 *	Tls_WaitForConnect --
 *
 *	Sideeffects:
 *		Issues SSL_accept or SSL_connect
 *
 *	Result:
 *		None.
 *
 *------------------------------------------------------*
 */
int Tls_WaitForConnect(State *statePtr, int *errorCodePtr, int handshakeFailureIsPermanent) {
	unsigned long backingError;
	int err, rc;
	int bioShouldRetry;

	dprintf("WaitForConnect(%p)", (void *) statePtr);
	dprintf("WaitForConnect(%p)", statePtr);
	dprintFlags(statePtr);

	if (!(statePtr->flags & TLS_TCL_INIT)) {
		dprintf("Tls_WaitForConnect called on already initialized channel -- returning with immediate success");
		*errorCodePtr = 0;
		return(0);
	}

} State;

#ifdef USE_TCL_STUBS
#ifndef Tcl_StackChannel
#error "Unable to compile on this version of Tcl"
#endif /* Tcl_GetStackedChannel */
#endif /* USE_TCL_STUBS */

#ifndef JOIN
#  define JOIN(a,b) JOIN1(a,b)
#  define JOIN1(a,b) a##b
#endif

#ifndef TCL_UNUSED
# if defined(__cplusplus)
#   define TCL_UNUSED(T) T
# elif defined(__GNUC__) && (__GNUC__ > 2)
#   define TCL_UNUSED(T) T JOIN(dummy, __LINE__) __attribute__((unused))
# else
#   define TCL_UNUSED(T) T JOIN(dummy, __LINE__)
# endif
#endif


/*
 * Forward declarations
 */
const Tcl_ChannelType *Tls_ChannelType(void);
Tcl_Channel     Tls_GetParent(State *statePtr, int maskFlags);

Tcl_Obj         *Tls_NewX509Obj(Tcl_Interp *interp, X509 *cert);
void            Tls_Error(State *statePtr, char *msg);
void            Tls_Free(char *blockPtr);
void            Tls_Free(void *blockPtr);
void            Tls_Clean(State *statePtr);
int             Tls_WaitForConnect(State *statePtr, int *errorCodePtr, int handshakeFailureIsPermanent);

BIO             *BIO_new_tcl(State* statePtr, int flags);

#define PTR2INT(x) ((int) ((intptr_t) (x)))