/*
 * Copyright (C) 1997-1999 Matt Newman <matt@novadigm.com>
 * some modifications:
 *	Copyright (C) 2000 Ajuba Solutions
 *	Copyright (C) 2002 ActiveState Corporation
 *	Copyright (C) 2004 Starfish Systems 
 *
 * $Header: /home/rkeene/tmp/cvs2fossil/../tcltls/tls/tls/tls.c,v 1.37 2015/07/07 17:16:02 andreas_kupries 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
 *

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

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

static SSL_CTX *CTX_Init _ANSI_ARGS_((State *statePtr, int proto, char *key,
			char *cert, char *CAdir, char *CAfile, char *ciphers,
			char *DHparams));

static int	TlsLibInit _ANSI_ARGS_ (()) ;

#define TLS_PROTO_SSL2		0x01
#define TLS_PROTO_SSL3		0x02
#define TLS_PROTO_TLS1		0x04
#define TLS_PROTO_TLS1_1	0x08
#define TLS_PROTO_TLS1_2	0x10
#define ENABLED(flag, mask)	(((flag) & (mask)) == (mask))

/*
 * Static data structures
 */

#ifndef OPENSSL_NO_DH
/* code derived from output of 'openssl dhparam -C 2048' */

static unsigned char dh2048_p[]={
	0xEC,0xFD,0x6F,0x66,0xD8,0xBC,0xB4,0xCB,0xD7,0xE7,0xB4,0xAE,
	0xEC,0xC0,0x06,0x25,0x40,0x9F,0x3F,0xC4,0xAC,0x34,0x19,0x36,
	0x8A,0xAB,0xA9,0xF6,0x45,0x36,0x87,0x1F,0x10,0x35,0x3F,0x90,
	0x00,0xC6,0x7A,0xE8,0x51,0xF4,0x7F,0x50,0x0F,0xC2,0x82,0x91,
	0xAD,0x60,0x1B,0x49,0xB1,0x0B,0x23,0xC3,0x37,0xAE,0x0D,0x2C,
	0x49,0xC6,0xFB,0x60,0x9D,0x50,0x2F,0x8C,0x2F,0xDE,0xE6,0x5F,
	0x53,0x8B,0x5F,0xF9,0x70,0x16,0xEE,0x51,0xD1,0xAB,0x02,0x48,
	0x61,0xF1,0xA0,0xD7,0xBD,0x04,0x24,0xF0,0xE4,0xD1,0x0A,0x4C,
	0x28,0xDC,0x22,0x78,0x7C,0xED,0x2A,0xFA,0xF4,0x57,0x7C,0xAE,
	0xDF,0x52,0xC6,0xA2,0x11,0x28,0xC5,0x3B,0xB8,0x2F,0x95,0x3F,
	0x1E,0x05,0x66,0xFE,0x7D,0x1A,0x73,0xA0,0x45,0xF8,0xBB,0x8C,
	0x64,0xB9,0xA9,0x4D,0x23,0xBE,0x20,0x60,0xA2,0xF7,0xC7,0xD8,
	0xD8,0x49,0x28,0x9A,0x81,0xAC,0xF9,0x7F,0x3C,0xFC,0xBE,0x25,
	0x5B,0x1D,0xB6,0xAB,0x08,0x06,0x11,0x8D,0x94,0x69,0x3C,0x68,
	0x98,0x5A,0x90,0xF8,0xEB,0x19,0xCA,0x9F,0x1C,0x50,0x96,0x53,
	0xEF,0xEC,0x1B,0x93,0x4F,0x53,0xB7,0xD9,0x04,0x8E,0x48,0x99,
	0x6E,0x24,0xFF,0x66,0xF5,0xB0,0xDF,0x00,0xBA,0x22,0xE2,0xB6,
	0xE3,0x3A,0xC2,0x95,0xB1,0x14,0x68,0xFB,0xA5,0x37,0x22,0x78,
	0x56,0x5C,0xA4,0x23,0x31,0x02,0x97,0x7D,0xA9,0x84,0x0B,0x12,
	0x26,0x58,0x2F,0x86,0x10,0xAD,0xB0,0xAB,0xB9,0x7B,0x05,0x9A,
	0xDE,0x11,0xF1,0xE7,0x34,0xC7,0x95,0x42,0x1C,0x4F,0xA9,0xA8,
	0x92,0xDF,0x3F,0x7B,
	};
static unsigned char dh2048_g[]={
	0x02,
};


static DH *get_dh2048()
{
    DH *dh=NULL;

    if ((dh=DH_new()) == NULL) return(NULL);

    dh->p=BN_bin2bn(dh2048_p,sizeof(dh2048_p),NULL);
    dh->g=BN_bin2bn(dh2048_g,sizeof(dh2048_g),NULL);

    if ((dh->p == NULL) || (dh->g == NULL))
	return(NULL);
    return(dh);
}
#endif

    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 *DHparams	= NULL;
    char *model		= NULL;
#ifndef OPENSSL_NO_TLSEXT
    char *servername	= NULL;	/* hostname for Server Name Indication */
#endif
#if defined(NO_SSL2)
    int ssl2 = 0;
#else

	    break;

	OPTSTR( "-cadir", CAdir);
	OPTSTR( "-cafile", CAfile);
	OPTSTR( "-certfile", cert);
	OPTSTR( "-cipher", ciphers);
	OPTOBJ( "-command", script);
	OPTSTR( "-dhparams", DHparams);
	OPTSTR( "-keyfile", key);
	OPTSTR( "-model", model);
	OPTOBJ( "-password", password);
	OPTBOOL( "-require", require);
	OPTBOOL( "-request", request);
	OPTBOOL( "-server", server);
#ifndef OPENSSL_NO_TLSEXT
        OPTSTR( "-servername", servername);
#endif

	OPTBOOL( "-ssl2", ssl2);
	OPTBOOL( "-ssl3", ssl3);
	OPTBOOL( "-tls1", tls1);
	OPTBOOL( "-tls1.1", tls1_1);
	OPTBOOL( "-tls1.2", tls1_2);

	OPTBAD( "option", "-cadir, -cafile, -certfile, -cipher, -command, -dhparams, -keyfile, -model, -password, -require, -request, -server, -servername, -ssl2, -ssl3, -tls1, -tls1.1 or -tls1.2");

	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);
    proto |= (tls1_1 ? TLS_PROTO_TLS1_1 : 0);
    proto |= (tls1_2 ? TLS_PROTO_TLS1_2 : 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 (DHparams && !*DHparams)	DHparams = NULL;

    /* new SSL state */
    statePtr		= (State *) ckalloc((unsigned) sizeof(State));
    memset(statePtr, 0, sizeof(State));

    statePtr->flags	= flags;
    statePtr->interp	= interp;

	    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, proto, key, cert, CAdir, CAfile, ciphers,
		DHparams)) == (SSL_CTX*)0) {
	    Tls_Free((char *) statePtr);
	    return TCL_ERROR;
	}
    }

    statePtr->ctx = ctx;

 * Side effects:
 *	constructs SSL context (CTX)
 *
 *-------------------------------------------------------------------
 */

static SSL_CTX *
CTX_Init(statePtr, proto, key, cert, CAdir, CAfile, ciphers, DHparams)
    State *statePtr;
    int proto;
    char *key;
    char *cert;
    char *CAdir;
    char *CAfile;
    char *ciphers;
    char *DHparams;
{
    Tcl_Interp *interp = statePtr->interp;
    SSL_CTX *ctx = NULL;
    Tcl_DString ds;
    Tcl_DString ds1;
    int off = 0;
    const SSL_METHOD *method;

	off |= (ENABLED(proto, TLS_PROTO_TLS1_1) ? 0 : SSL_OP_NO_TLSv1_1);
#endif
#if !defined(NO_TLS1_2)
	off |= (ENABLED(proto, TLS_PROTO_TLS1_2) ? 0 : SSL_OP_NO_TLSv1_2);
#endif
	break;
    }
    
    ctx = SSL_CTX_new (method);
    
    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);

    /* set some callbacks */
    SSL_CTX_set_default_passwd_cb(ctx, PasswordCallback);

#ifndef BSAFE
    SSL_CTX_set_default_passwd_cb_userdata(ctx, (void *)statePtr);
#endif

    /* read a Diffie-Hellman parameters file, or use the built-in one */
#ifdef OPENSSL_NO_DH
    if (DHparams != NULL) {
	Tcl_AppendResult(interp,
	    "DH parameter support not available", (char *) NULL);
	SSL_CTX_free(ctx);
	return (SSL_CTX *)0;
    }
#else
    {
	DH* dh;
	if (DHparams != NULL) {
	    BIO *bio;
	    Tcl_DStringInit(&ds);
	    bio = BIO_new_file(F2N(DHparams, &ds), "r");
	    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);
		return (SSL_CTX *)0;
	    }
	} else {
	    dh = get_dh2048();
	}
	SSL_CTX_set_tmp_dh(ctx, dh);
	DH_free(dh);
    }
#endif

    /* set our certificate */
    if (cert != NULL) {