/*
 * Copyright (C) 1997-1999 Matt Newman <[email protected]>
 * some modifications:
 *	Copyright (C) 2000 Ajuba Solutions
 *	Copyright (C) 2002 ActiveState Corporation
 *	Copyright (C) 2004 Starfish Systems 
 *
 * 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
 *

 */

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

static void	InfoCallback(CONST SSL *ssl, int where, int ret);

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

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

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

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

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

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

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

static SSL_CTX *CTX_Init(State *statePtr, int isServer, int proto, char *key,
			char *certfile, unsigned char *key_asn1, unsigned char *cert_asn1,
			int key_asn1_len, int cert_asn1_len, char *CAdir, char *CAfile,
      char *ciphers, char *DHparams);

static int	TlsLibInit(int uninitialize);

 *	None
 *
 * Side effects:
 *	Calls callback (if defined)
 *-------------------------------------------------------------------
 */
static void
InfoCallback(CONST SSL *ssl, int where, int ret)
{
    State *statePtr = (State*)SSL_get_app_data((SSL *)ssl);
    Tcl_Obj *cmdPtr;
    char *major; char *minor;

    dprintf("Called");

	if (where & SSL_CB_READ)		minor = "read";
	else if (where & SSL_CB_WRITE)		minor = "write";
	else if (where & SSL_CB_LOOP)		minor = "loop";
	else if (where & SSL_CB_EXIT)		minor = "exit";
	else					minor = "unknown";
    }

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

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

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

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

    if (where & (SSL_CB_LOOP|SSL_CB_EXIT)) {
	Tcl_ListObjAppendElement( statePtr->interp, cmdPtr,
	    Tcl_NewStringObj( SSL_state_string_long(ssl), -1) );
    } else if (where & SSL_CB_ALERT) {
	CONST char *cp = (char *) SSL_alert_desc_string_long(ret);

	Tcl_ListObjAppendElement( statePtr->interp, cmdPtr,
	    Tcl_NewStringObj( cp, -1) );
    } else {
	Tcl_ListObjAppendElement( statePtr->interp, cmdPtr,
	    Tcl_NewStringObj( SSL_state_string_long(ssl), -1) );
    }

	    return ok;
	} else {
	    return 1;
	}
    }
    cmdPtr = Tcl_DuplicateObj(statePtr->callback);

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

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

    Tcl_ListObjAppendElement( statePtr->interp, cmdPtr,
	    Tcl_NewIntObj( depth) );

    Tcl_ListObjAppendElement( statePtr->interp, cmdPtr,
	    Tls_NewX509Obj( statePtr->interp, cert) );

    Tcl_Obj *cmdPtr;

    dprintf("Called");

    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_Release((ClientData) statePtr);
    Tcl_Release((ClientData) statePtr->interp);
}

/*
 *-------------------------------------------------------------------
 *
 * PasswordCallback -- 
 *
 *	Called when a password is needed to unpack RSA and PEM keys.
 *	Evals any bound password script and returns the result as
 *	the password string.
 *-------------------------------------------------------------------
 */
#ifdef PRE_OPENSSL_0_9_4

 *-------------------------------------------------------------------
 */
static int
CiphersObjCmd(clientData, interp, objc, objv)
    ClientData clientData;	/* Not used. */
    Tcl_Interp *interp;
    int objc;
    Tcl_Obj	*CONST objv[];
{
    static CONST84 char *protocols[] = {
	"ssl2",	"ssl3",	"tls1",	"tls1.1", "tls1.2", "tls1.3", NULL
    };
    enum protocol {
	TLS_SSL2, TLS_SSL3, TLS_TLS1, TLS_TLS1_1, TLS_TLS1_2, TLS_TLS1_3, TLS_NONE
    };
    Tcl_Obj *objPtr;
    SSL_CTX *ctx = NULL;

 *
 * Side effects:
 *	May force SSL negotiation to take place.
 *
 *-------------------------------------------------------------------
 */

static int HandshakeObjCmd(ClientData clientData, 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 */
	CONST char *errStr = NULL;
	int ret = 1;
	int err = 0;

	dprintf("Called");

	if (objc != 2) {
		Tcl_WrongNumArgs(interp, 1, objv, "channel");
		return(TCL_ERROR);
	}

	chan = Tcl_GetChannel(interp, Tcl_GetStringFromObj(objv[1], NULL), NULL);
	if (chan == (Tcl_Channel) NULL) {
		return(TCL_ERROR);
	}

	/*
	 * Make sure to operate on the topmost channel
	 */

 */

static int
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;
    Tcl_Obj *password	        = NULL;
    Tcl_DString upperChannelTranslation, upperChannelBlocking, upperChannelEncoding, upperChannelEOFChar;

#endif

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "channel ?options?");
	return TCL_ERROR;
    }

    chan = Tcl_GetChannel(interp, Tcl_GetStringFromObj(objv[1], NULL), NULL);
    if (chan == (Tcl_Channel) NULL) {
	return TCL_ERROR;
    }

    /*
     * Make sure to operate on the topmost channel
     */
    chan = Tcl_GetTopChannel(chan);

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

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

	OPTSTR( "-cadir", CAdir);
	OPTSTR( "-cafile", CAfile);
	OPTSTR( "-certfile", certfile);

    }

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

    statePtr->ctx = ctx;

    /*

    Tcl_GetChannelOption(interp, chan, "-eofchar", &upperChannelEOFChar);
    Tcl_GetChannelOption(interp, chan, "-encoding", &upperChannelEncoding);
    Tcl_GetChannelOption(interp, chan, "-translation", &upperChannelTranslation);
    Tcl_GetChannelOption(interp, chan, "-blocking", &upperChannelBlocking);
    Tcl_SetChannelOption(interp, chan, "-translation", "binary");
    Tcl_SetChannelOption(interp, chan, "-blocking", "true");
    dprintf("Consuming Tcl channel %s", Tcl_GetChannelName(chan));
    statePtr->self = Tcl_StackChannel(interp, Tls_ChannelType(), (ClientData) 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);
	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);
	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);
            return TCL_ERROR;
        }
    }
#endif

    /*
     * SSL Callbacks
     */

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

    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_NOCLOSE);

 */

static int
UnimportObjCmd(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. */

    dprintf("Called");

    if (objc != 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "channel");

	off |= (ENABLED(proto, TLS_PROTO_TLS1_2) ? 0 : SSL_OP_NO_TLSv1_2);
#endif
#if !defined(NO_TLS1_3)
	off |= (ENABLED(proto, TLS_PROTO_TLS1_3) ? 0 : SSL_OP_NO_TLSv1_3);
#endif
	break;
    }
    
    ctx = SSL_CTX_new (method);

    if (!ctx) {
        return(NULL);
    }

#if !defined(NO_TLS1_3)
    if (proto == TLS_PROTO_TLS1_3) {
        SSL_CTX_set_min_proto_version (ctx, TLS1_3_VERSION);
        SSL_CTX_set_max_proto_version (ctx, TLS1_3_VERSION);
    }
#endif
    
    SSL_CTX_set_app_data( ctx, (VOID*)interp);	/* remember the interpreter */
    SSL_CTX_set_options( ctx, SSL_OP_ALL);	/* all SSL bug workarounds */
    SSL_CTX_set_options( ctx, off);	/* all SSL bug workarounds */
    SSL_CTX_sess_set_cache_size( ctx, 128);

    if (ciphers != NULL)
	SSL_CTX_set_cipher_list(ctx, ciphers);

	    if (!bio) {
		Tcl_DStringFree(&ds);
		Tcl_AppendResult(interp,
		    "Could not find DH parameters file", (char *) NULL);
		SSL_CTX_free(ctx);
		return (SSL_CTX *)0;
	    }
	    
	    dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
	    BIO_free(bio);
	    Tcl_DStringFree(&ds);
	    if (!dh) {
		Tcl_AppendResult(interp,
		    "Could not read DH parameters from file", (char *) NULL);
		SSL_CTX_free(ctx);

#endif
    }

    /* https://sourceforge.net/p/tls/bugs/57/ */
    /* XXX:TODO: Let the user supply values here instead of something that exists on the filesystem */
    if ( CAfile != NULL ) {
        STACK_OF(X509_NAME) *certNames = SSL_load_client_CA_file( F2N(CAfile, &ds) );
	if ( certNames != NULL ) { 
	    SSL_CTX_set_client_CA_list(ctx, certNames );
	}
    }

    Tcl_DStringFree(&ds);
    Tcl_DStringFree(&ds1);
    return ctx;

 *-------------------------------------------------------------------
 */
static int
StatusObjCmd(clientData, interp, objc, objv)
    ClientData clientData;	/* Not used. */
    Tcl_Interp *interp;
    int objc;
    Tcl_Obj	*CONST objv[];
{
    State *statePtr;
    X509 *peer;
    Tcl_Obj *objPtr;
    Tcl_Channel chan;
    char *channelName, *ciphers;
    int mode;

    dprintf("Called");

    switch (objc) {
	case 2:
	    channelName = Tcl_GetStringFromObj(objv[1], NULL);
	    break;

	case 3:
	    if (!strcmp (Tcl_GetString (objv[1]), "-local")) {
		channelName = Tcl_GetStringFromObj(objv[2], NULL);
		break;
	    }
	    /* else fall... */
	default:
	    Tcl_WrongNumArgs(interp, 1, objv, "?-local? channel");
	    return TCL_ERROR;
    }

 *-------------------------------------------------------------------
 */
static int
VersionObjCmd(clientData, interp, objc, objv)
    ClientData clientData;	/* Not used. */
    Tcl_Interp *interp;
    int objc;
    Tcl_Obj	*CONST objv[];
{
    Tcl_Obj *objPtr;

    dprintf("Called");

    objPtr = Tcl_NewStringObj(OPENSSL_VERSION_TEXT, -1);

 *-------------------------------------------------------------------
 */
static int
MiscObjCmd(clientData, interp, objc, objv)
    ClientData clientData;	/* Not used. */
    Tcl_Interp *interp;
    int objc;
    Tcl_Obj	*CONST objv[];
{
    static CONST84 char *commands [] = { "req", NULL };
    enum command { C_REQ, C_DUMMY };
    int cmd;

    dprintf("Called");

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "subcommand ?args?");

	    int listc,i;

	    BIO *out=NULL;

	    char *k_C="",*k_ST="",*k_L="",*k_O="",*k_OU="",*k_CN="",*k_Email="";
	    char *keyout,*pemout,*str;
	    int keysize,serial=0,days=365;
	    
	    if ((objc<5) || (objc>6)) {
		Tcl_WrongNumArgs(interp, 2, objv, "keysize keyfile certfile ?info?");
		return TCL_ERROR;
	    }

	    if (Tcl_GetIntFromObj(interp, objv[2], &keysize) != TCL_OK) {
		return TCL_ERROR;

		}

		X509_set_version(cert,2);
		ASN1_INTEGER_set(X509_get_serialNumber(cert),serial);
		X509_gmtime_adj(X509_get_notBefore(cert),0);
		X509_gmtime_adj(X509_get_notAfter(cert),(long)60*60*24*days);
		X509_set_pubkey(cert,pkey);
		
		name=X509_get_subject_name(cert);

		X509_NAME_add_entry_by_txt(name,"C", MBSTRING_ASC, (unsigned char *) k_C, -1, -1, 0);
		X509_NAME_add_entry_by_txt(name,"ST", MBSTRING_ASC, (unsigned char *) k_ST, -1, -1, 0);
		X509_NAME_add_entry_by_txt(name,"L", MBSTRING_ASC, (unsigned char *) k_L, -1, -1, 0);
		X509_NAME_add_entry_by_txt(name,"O", MBSTRING_ASC, (unsigned char *) k_O, -1, -1, 0);
		X509_NAME_add_entry_by_txt(name,"OU", MBSTRING_ASC, (unsigned char *) k_OU, -1, -1, 0);

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

    dprintf("Called");

    Tls_Clean(statePtr);
    ckfree(blockPtr);

        dprintf("Called");

	/*
	 * We only support Tcl 8.4 or newer
	 */
	if (
#ifdef USE_TCL_STUBS
	    Tcl_InitStubs(interp, "8.4", 0)
#else
	    Tcl_PkgRequire(interp, "Tcl", "8.4", 0)
#endif
	     == NULL) {
		return TCL_ERROR;
	}

	if (TlsLibInit(0) != TCL_OK) {
		Tcl_AppendResult(interp, "could not initialize SSL library", NULL);

/*
 *------------------------------------------------------*
 *
 *	Tls_SafeInit --
 *
 *	------------------------------------------------*
 *	Standard procedure required by 'load'. 
 *	Initializes this extension for a safe interpreter.
 *	------------------------------------------------*
 *
 *	Sideeffects:
 *		As of 'Tls_Init'
 *
 *	Result:

	 * terrible entropy
	 */
    /*
     * Seed the random number generator in the SSL library,
     * using the do/while construct because of the bug note in the
     * OpenSSL FAQ at http://www.openssl.org/support/faq.html#USER1
     *
     * The crux of the problem is that Solaris 7 does not have a 
     * /dev/random or /dev/urandom device so it cannot gather enough
     * entropy from the RAND_seed() when TLS initializes and refuses
     * to go further. Earlier versions of OpenSSL carried on regardless.
     */
    srand((unsigned int) time((time_t *) NULL));
    do {
	for (i = 0; i < 16; i++) {