}

    if (model != NULL) {
	int mode;
	/* Get the "model" context */
	chan = Tcl_GetChannel(interp, model, &mode);
	if (chan == (Tcl_Channel) NULL) {
	    Tls_Free((void *)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", (char *)NULL);
	    Tcl_SetErrorCode(interp, "TLS", "IMPORT", "CHANNEL", "INVALID", (char *)NULL);
	    Tls_Free((void *)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, CApath, CAfile, ciphers, NULL, 0, DHparams)) == NULL) {
	    Tls_Free((void *)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((void *)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: ", GET_ERR_REASON(), (char *)NULL);
	Tcl_SetErrorCode(interp, "TLS", "IMPORT", "INIT", "FAILED", (char *)NULL);
	Tls_Free((void *)statePtr);
	Tls_Free(statePtr);
	return TCL_ERROR;
    }

    /* Set host server name */
    if (servername) {
	/* Sets the server name indication (SNI) in ClientHello extension */
	/* Per RFC 6066, hostname is a ASCII encoded string, though RFC 4366 says UTF-8. */
	if (!SSL_set_tlsext_host_name(statePtr->ssl, servername) && require) {
	    Tcl_AppendResult(interp, "setting TLS host name extension failed", (char *)NULL);
	    Tcl_SetErrorCode(interp, "TLS", "IMPORT", "HOSTNAME", "FAILED", (char *)NULL);
	    Tls_Free((void *)statePtr);
	    Tls_Free(statePtr);
	    return TCL_ERROR;
	}
    }

    /*
     * SSL Callbacks
     */

 *	none
 *
 * Side effects:
 *	Frees all the state
 *
 *-------------------------------------------------------------------
 */
#undef Tls_Free
void
#if TCL_MAJOR_VERSION > 8
Tls_Free( void *blockPtr )
#else
Tls_Free( char *blockPtr )
#endif
{

Tcl_Obj        *Tls_NewX509Obj(Tcl_Interp *interp, X509 *cert);
void            Tls_Error(State *statePtr, const char *msg);
#if TCL_MAJOR_VERSION > 8
void            Tls_Free(void *blockPtr);
#else
void            Tls_Free(char *blockPtr);
#define Tls_Free(blockPtr) (Tls_Free)((char *)blockPtr)
#endif
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)))