/*
 * Copyright (C) 1997-1999 Matt Newman <matt@novadigm.com>
 *
 * $Header: /home/rkeene/tmp/cvs2fossil/../tcltls/tls/tls/tls.c,v 1.7 2000/07/27 01:58:18 hobbs Exp $
 *
 * TLS (aka SSL) Channel - can be layered on any bi-directional
 * Tcl_Channel (Note: Requires Trf Core Patch)
 *
 * This was built (almost) from scratch based upon observation of
 * OpenSSL 0.9.2B
 *

 */

/*
 * Forward declarations
 */

#define F2N( key, dsp) \
	(((key) == NULL) ? (char *) NULL : \
		Tcl_TranslateFileName(interp, (key), (dsp)))
#define REASON()	ERR_reason_error_string(ERR_get_error())

static int	CiphersObjCmd _ANSI_ARGS_ ((ClientData clientData,
			Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]));

static int	HandshakeObjCmd _ANSI_ARGS_ ((ClientData clientData,
			Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]));

static int	ImportObjCmd _ANSI_ARGS_ ((ClientData clientData,
			Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]));

static int	StatusObjCmd _ANSI_ARGS_ ((ClientData clientData,
			Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]));
static SSL_CTX *CTX_Init _ANSI_ARGS_((Tcl_Interp *interp, int proto, char *key,
			char *cert, char *CAdir, char *CAfile, char *ciphers));

#define TLS_PROTO_SSL2	0x01
#define TLS_PROTO_SSL3	0x02
#define TLS_PROTO_TLS1	0x04
#define ENABLED(flag, mask)	(((flag) & (mask)) == (mask))

/*
 * Static data structures
 */

#ifndef NO_DH
/* from openssl/apps/s_server.c */

 *	The err field of the currently operative State is set
 *	  to a string describing the SSL negotiation failure reason
 *-------------------------------------------------------------------
 */
static int
VerifyCallback(int ok, X509_STORE_CTX *ctx)
{
    Tcl_Obj *cmdPtr;
    char *errStr;
    SSL   *ssl		= (SSL*)X509_STORE_CTX_get_app_data(ctx);
    X509  *cert		= X509_STORE_CTX_get_current_cert(ctx);
    State *statePtr	= (State*)SSL_get_app_data(ssl);

    int depth		= X509_STORE_CTX_get_error_depth(ctx);
    int err		= X509_STORE_CTX_get_error(ctx);


    dprintf(stderr, "Verify: %d\n", ok);

    if (!ok) {
	errStr = (char*)X509_verify_cert_error_string(err);
    } else {
	errStr = (char *)0;
    }

    if (statePtr->callback == (Tcl_Obj*)NULL) {
	if (statePtr->vflags & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) {
	    return ok;
	} else {
	    return 1;
	}
    }
    cmdPtr = Tcl_DuplicateObj(statePtr->callback);

    Tcl_ListObjAppendElement( statePtr->interp, cmdPtr, 
	    Tcl_NewStringObj( "verify", -1));

    Tcl_ListObjAppendElement( statePtr->interp, cmdPtr, 

 */
void
Tls_Error(State *statePtr, char *msg)
{
    Tcl_Obj *cmdPtr;

    if (msg && *msg) {
	Tcl_SetErrorCode(statePtr->interp, "SSL", msg, (char *)NULL);
    } else {
	msg = Tcl_GetStringFromObj(Tcl_GetObjResult(statePtr->interp), NULL);
    }
    statePtr->err = msg;

    if (statePtr->callback == (Tcl_Obj*)NULL) {
	char buf[BUFSIZ];
	sprintf(buf, "SSL channel \"%s\": error: %s",
	    Tcl_GetChannelName(statePtr->self), msg);
	Tcl_SetResult( statePtr->interp, buf, TCL_VOLATILE);
	Tcl_BackgroundError( statePtr->interp);
	return;
    }
    cmdPtr = Tcl_DuplicateObj(statePtr->callback);

    Tcl_ListObjAppendElement(statePtr->interp, cmdPtr, 
	    Tcl_NewStringObj("error", -1));

    Tcl_ListObjAppendElement(statePtr->interp, cmdPtr, 
	    Tcl_NewStringObj(Tcl_GetChannelName(statePtr->self), -1));

    Tcl_ListObjAppendElement(statePtr->interp, cmdPtr,
	    Tcl_NewStringObj(msg, -1));

    Tcl_Preserve((ClientData) statePtr->interp);
    Tcl_Preserve((ClientData) statePtr);

    Tcl_IncrRefCount(cmdPtr);
    if (Tcl_GlobalEvalObj(statePtr->interp, cmdPtr) != TCL_OK) {
	Tcl_BackgroundError(statePtr->interp);
    }
    Tcl_DecrRefCount(cmdPtr);

    Tcl_Release((ClientData) statePtr);
    Tcl_Release((ClientData) statePtr->interp);
}

/*
 *-------------------------------------------------------------------
 *
 * PasswordCallback -- 
 *

		Tcl_AppendResult(interp, "protocol not supported", NULL);
		return TCL_ERROR;
#else
		ctx = SSL_CTX_new(TLSv1_method()); break;
#endif
    }
    if (ctx == NULL) {
	Tcl_AppendResult(interp, REASON(), (char *) NULL);

	return TCL_ERROR;
    }
    ssl = SSL_new(ctx);
    if (ssl == NULL) {
	Tcl_AppendResult(interp, REASON(), (char *) NULL);

	SSL_CTX_free(ctx);
	return TCL_ERROR;
    }
    objPtr = Tcl_NewListObj( 0, NULL);

    if (!verbose) {
	for (index = 0; ; index++) {

        return TCL_ERROR;
    }

    chan = Tcl_GetChannel(interp, Tcl_GetStringFromObj(objv[1], NULL), NULL);
    if (chan == (Tcl_Channel) NULL) {
        return TCL_ERROR;
    }
#ifdef TCL_CHANNEL_VERSION_2
    /*
     * Make sure to operate on the topmost channel
     */
    chan = Tcl_GetTopChannel(chan);
#endif
    if (Tcl_GetChannelType(chan) != Tls_ChannelType()) {
        Tcl_AppendResult(interp, "bad channel \"", Tcl_GetChannelName(chan),
                "\": not a TLS channel", NULL);
        return TCL_ERROR;
    }
    statePtr = (State *)Tcl_GetChannelInstanceData(chan);

    if (!SSL_is_init_finished(statePtr->ssl)) {
	int err;
	ret = Tls_WaitForConnect(statePtr, &err);
	if (ret < 0) {
	    char *errStr = statePtr->err;
	    Tcl_ResetResult(interp);
	    Tcl_SetErrno(err);

	    if (!errStr || *errStr == 0) {
	        errStr = Tcl_PosixError(interp);
	    }

	    Tcl_AppendResult(interp, "handshake failed: ", errStr,
		    (char *) NULL);
	    return TCL_ERROR;
	}
    }

    Tcl_SetObjResult(interp, Tcl_NewIntObj(ret));
    return TCL_OK;
}

/*
 *-------------------------------------------------------------------
 *

ImportObjCmd(clientData, interp, objc, objv)
    ClientData clientData;	/* Not used. */
    Tcl_Interp *interp;
    int objc;
    Tcl_Obj *CONST objv[];
{
    Tcl_Channel chan;		/* The channel to set a mode on. */

    State *statePtr;		/* client state for ssl socket */
    SSL_CTX *ctx	= NULL;
    Tcl_Obj *script	= NULL;
    int idx;
    int flags		= TLS_TCL_INIT;
    int server		= 0;	/* is connection incoming or outgoing? */
    char *key		= NULL;
    char *cert		= NULL;
    char *ciphers	= NULL;
    char *CAfile	= NULL;
    char *CAdir		= NULL;
    char *model		= NULL;
#if defined(NO_SSL2)
    int ssl2 = 0;
#else
    int ssl2 = 1;
#endif
#if defined(NO_SSL3)
    int ssl3 = 0;

        return TCL_ERROR;
    }

    chan = Tcl_GetChannel(interp, Tcl_GetStringFromObj(objv[1], NULL), NULL);
    if (chan == (Tcl_Channel) NULL) {
        return TCL_ERROR;
    }
#ifdef TCL_CHANNEL_VERSION_2
    /*
     * Make sure to operate on the topmost channel
     */
    chan = Tcl_GetTopChannel(chan);
#endif

    for (idx = 2; idx < objc; idx++) {
	char *opt = Tcl_GetStringFromObj(objv[idx], NULL);

	if (opt[0] != '-')
	    break;

	OPTBOOL( "-ssl3", ssl3);
	OPTBOOL( "-tls1", tls1);

	OPTBAD( "option", "-cafile, -cadir, -certfile, -cipher, -command, -keyfile, -model, -require, -request, -ssl2, -ssl3, -server, or -tls1");

	return TCL_ERROR;
    }
    if (request)            verify |= SSL_VERIFY_CLIENT_ONCE | SSL_VERIFY_PEER;
    if (request && require) verify |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
    if (verify == 0)        verify = SSL_VERIFY_NONE;

    proto |= (ssl2 ? TLS_PROTO_SSL2 : 0);
    proto |= (ssl3 ? TLS_PROTO_SSL3 : 0);
    proto |= (tls1 ? TLS_PROTO_TLS1 : 0);

    /* reset to NULL if blank string provided */
    if (cert && !*cert)		cert	= NULL;
    if (key && !*key)		key	= NULL;
    if (ciphers && !*ciphers)	ciphers	= NULL;
    if (CAfile && !*CAfile)	CAfile	= NULL;
    if (CAdir && !*CAdir)	CAdir	= NULL;

    if (model != NULL) {
	int mode;
	/* Get the "model" context */
	chan = Tcl_GetChannel(interp, model, &mode);
	if (chan == (Tcl_Channel) NULL) {
	    return TCL_ERROR;
	}
#ifdef TCL_CHANNEL_VERSION_2
	/*
	 * Make sure to operate on the topmost channel
	 */
	chan = Tcl_GetTopChannel(chan);
#endif
	if (Tcl_GetChannelType(chan) != Tls_ChannelType()) {
	    Tcl_AppendResult(interp, "bad channel \"",
		    Tcl_GetChannelName(chan), "\": not a TLS channel", NULL);
	    return TCL_ERROR;
	}
	statePtr = (State *) Tcl_GetChannelInstanceData(chan);
	ctx = statePtr->ctx;
    } else {
	if ((ctx = CTX_Init(interp, proto, key, cert, CAdir, CAfile, ciphers))
	    == (SSL_CTX*)0) {
	    return TCL_ERROR;
	}
    }

    /* new SSL state */
    statePtr		= (State *) Tcl_Alloc((unsigned) sizeof(State));
    statePtr->self	= (Tcl_Channel)NULL;
    statePtr->timer	= (Tcl_TimerToken)NULL;

    statePtr->flags	= flags;
    statePtr->watchMask	= 0;
    statePtr->mode	= 0;

    statePtr->interp	= interp;
    statePtr->callback	= (Tcl_Obj *)0;

    statePtr->vflags	= verify;
    statePtr->ssl	= (SSL*)0;
    statePtr->ctx	= ctx;
    statePtr->bio	= (BIO*)0;
    statePtr->p_bio	= (BIO*)0;

    statePtr->err	= "";

    /*
     * We need to make sure that the channel works in binary (for the
     * encryption not to get goofed up).
     * We only want to adjust the buffering in pre-v2 channels, where
     * each channel in the stack maintained its own buffers.
     */
    Tcl_SetChannelOption(interp, chan, "-translation", "binary");
#ifndef TCL_CHANNEL_VERSION_2
    Tcl_SetChannelOption(interp, chan, "-buffering", "none");
#endif

#if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION < 2
    statePtr->parent = chan;
    statePtr->self = Tcl_ReplaceChannel(interp,
	    Tls_ChannelType(), (ClientData) statePtr,
	    (TCL_READABLE | TCL_WRITABLE), statePtr->parent);
#else
#ifdef TCL_CHANNEL_VERSION_2
    statePtr->self = Tcl_StackChannel(interp, Tls_ChannelType(),
	    (ClientData) statePtr, (TCL_READABLE | TCL_WRITABLE), chan);
#else
    statePtr->self = chan;
    Tcl_StackChannel( interp, Tls_ChannelType(), (ClientData) statePtr,
	    (TCL_READABLE | TCL_WRITABLE), chan);
#endif
#endif
    if (statePtr->self == (Tcl_Channel) NULL) {
	/*
	 * No use of Tcl_EventuallyFree because no possible Tcl_Preserve.
	 */
	Tls_Free((char *) statePtr);
        return TCL_ERROR;
    }

    /* allocate script */
    if (script) {
	char *tmp = Tcl_GetStringFromObj(script, NULL);
	if (tmp && *tmp) {
	    statePtr->callback = Tcl_DuplicateObj(script);
	    Tcl_IncrRefCount(statePtr->callback);
	}
    }
    /* This is only needed because of a bug in OpenSSL, where the
     * ssl->verify_callback is not referenced!!! (Must be done
     * *before* SSL_new() is called!
     */
    SSL_CTX_set_verify(statePtr->ctx, verify, VerifyCallback);

    /*
     * 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);
        return TCL_ERROR;
    }

    /*
     * SSL Callbacks
     */

    SSL_set_app_data(statePtr->ssl, (VOID *)statePtr);	/* point back to us */

    /*
     * The following is broken - we need is to set the
     * verify_mode, but the library ignores the verify_callback!!!
     */
    /*SSL_set_verify(statePtr->ssl, verify, VerifyCallback);*/

    SSL_CTX_set_info_callback(statePtr->ctx, InfoCallback);

    /* Create Tcl_Channel BIO Handler */
    statePtr->p_bio	= BIO_new_tcl(statePtr, BIO_CLOSE);
    statePtr->bio	= BIO_new(BIO_f_ssl());

    if (server) {
	statePtr->flags |= TLS_TCL_SERVER;
	SSL_set_accept_state(statePtr->ssl);
    } else {
	SSL_set_connect_state(statePtr->ssl);
    }
    SSL_set_bio(statePtr->ssl, statePtr->p_bio, statePtr->p_bio);
    BIO_set_ssl(statePtr->bio, statePtr->ssl, BIO_CLOSE);

    /*
     * End of SSL Init
     */
    Tcl_SetResult(interp, Tcl_GetChannelName(statePtr->self), TCL_VOLATILE);
    return TCL_OK;

    if (!SSL_CTX_load_verify_locations(ctx, F2N(CAfile, &ds), F2N(CAdir, &ds1)) ||
        !SSL_CTX_set_default_verify_paths(ctx)) {
#if 0
	Tcl_DStringFree(&ds);
	Tcl_DStringFree(&ds1);
	/* Don't currently care if this fails */
	Tcl_AppendResult(interp, "SSL default verify paths: ",
		REASON(), (char *) NULL);
	SSL_CTX_free(ctx);
	return (SSL_CTX *)0;
#endif
    }
    SSL_CTX_set_client_CA_list(ctx, SSL_load_client_CA_file( F2N(CAfile, &ds) ));

    Tcl_DStringFree(&ds);

    if (objc != 2) {
        Tcl_WrongNumArgs(interp, 1, objv, "channel");
        return TCL_ERROR;
    }
    channelName = Tcl_GetStringFromObj(objv[1], NULL);

    chan = Tcl_GetChannel(interp, channelName, &mode);
    if (chan == (Tcl_Channel) NULL) {
	return TCL_ERROR;
    }
#ifdef TCL_CHANNEL_VERSION_2
    /*
     * Make sure to operate on the topmost channel
     */
    chan = Tcl_GetTopChannel(chan);
#endif
    if (Tcl_GetChannelType(chan) != Tls_ChannelType()) {
        Tcl_AppendResult(interp, "bad channel \"", Tcl_GetChannelName(chan),
                "\": not a TLS channel", NULL);
        return TCL_ERROR;
    }
    statePtr	= (State *) Tcl_GetChannelInstanceData(chan);
    peer	= SSL_get_peer_certificate(statePtr->ssl);
    if (peer) {
	objPtr = Tls_NewX509Obj(interp, peer);
    } else {
	objPtr = Tcl_NewListObj(0, NULL);
    }

    ciphers = (char*)SSL_get_cipher(statePtr->ssl);
    if (ciphers != NULL && strcmp(ciphers, "(NONE)")!=0) {
	Tcl_ListObjAppendElement(interp, objPtr,
		Tcl_NewStringObj("cipher", -1));
	Tcl_ListObjAppendElement(interp, objPtr,
		Tcl_NewStringObj(SSL_get_cipher(statePtr->ssl), -1));
    }
    Tcl_SetObjResult( interp, objPtr);
    return TCL_OK;
}

/*
 *-------------------------------------------------------------------

 *	Frees all the state
 *
 *-------------------------------------------------------------------
 */
void
Tls_Clean(State *statePtr)
{
    /*
     * we're assuming here that we're single-threaded
     */

    if (statePtr->timer != (Tcl_TimerToken) NULL) {
	Tcl_DeleteTimerHandler(statePtr->timer);
	statePtr->timer = NULL;
    }

    if (statePtr->ssl) {
	SSL_shutdown(statePtr->ssl);
	SSL_free(statePtr->ssl);
	statePtr->ssl = NULL;
    }
    if (statePtr->callback) {
	Tcl_DecrRefCount(statePtr->callback);
	statePtr->callback = NULL;
    }





}

/*
 *-------------------------------------------------------------------
 *
 * Tls_Init --
 *

                                         * to be made available. */
{
#if TCL_MAJOR_VERSION >= 8 && TCL_MINOR_VERSION >= 2
    if (!Tcl_InitStubs(interp, TCL_VERSION, 0)) {
        return TCL_ERROR;
    }
#endif
    if (SSL_library_init() != 1) {
        Tcl_AppendResult(interp, "could not initialize SSL library", NULL);
	return TCL_ERROR;
    }
    SSL_load_error_strings();
    ERR_load_crypto_strings();


    Tcl_CreateObjCommand(interp, "tls::ciphers", CiphersObjCmd,
	    (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);

    Tcl_CreateObjCommand(interp, "tls::handshake", HandshakeObjCmd,
	    (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);

    Tcl_CreateObjCommand(interp, "tls::import", ImportObjCmd,
	    (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);

    Tcl_CreateObjCommand(interp, "tls::status", StatusObjCmd,
	    (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);

    return Tcl_PkgProvide(interp, PACKAGE, VERSION);
}


/*
 *------------------------------------------------------*
 *
 *	Tls_SafeInit --
 *
 *	------------------------------------------------*