/*
 * 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 
 *
 * $Header: /home/rkeene/tmp/cvs2fossil/../tcltls/tls/tls/tls.c,v 1.33 2012/07/09 23:28:02 andreas_kupries Exp $
 * $Header: /home/rkeene/tmp/cvs2fossil/../tcltls/tls/tls/tls.c,v 1.34 2014/04/16 18:33:03 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
 *

			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));

static int	TlsLibInit _ANSI_ARGS_ (()) ;

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

/*

/*
 * Threaded operation requires locking callbacks
 * Based from /crypto/cryptlib.c of OpenSSL and NSOpenSSL.
 */

static Tcl_Mutex locks[CRYPTO_NUM_LOCKS];
static Tcl_Mutex init_mx;
static int initialized;

static void          CryptoThreadLockCallback (int mode, int n, const char *file, int line);
static unsigned long CryptoThreadIdCallback   (void);

static void
CryptoThreadLockCallback(int mode, int n, const char *file, int line)
{

 *-------------------------------------------------------------------
 */

int
Tls_Init(Tcl_Interp *interp)		/* Interpreter in which the package is
					 * to be made available. */
{
    int major, minor, patchlevel, release, i;
    int major, minor, patchlevel, release;
    char rnd_seed[16] = "GrzSlplKqUdnnzP!";	/* 16 bytes */
#if defined(OPENSSL_THREADS) && defined(TCL_THREADS)
    size_t num_locks;
#endif

    /*
     * The original 8.2.0 stacked channel implementation (and the patch
     * that preceded it) had problems with scalability and robustness.
     * These were address in 8.3.2 / 8.4a2, so we now require that as a
     * minimum for TLS 1.4+.  We only support 8.2+ now (8.3.2+ preferred).
     */

	/* 8.3.2+ */
	channelTypeVersion = TLS_CHANNEL_VERSION_2;
    } else {
	/* 8.2.0 - 8.3.1 */
	channelTypeVersion = TLS_CHANNEL_VERSION_1;
    }

    if (CRYPTO_set_mem_functions((void *(*)(size_t))Tcl_Alloc,
				 (void *(*)(void *, size_t))Tcl_Realloc,
				 (void(*)(void *))Tcl_Free) == 0) {
       /* Not using Tcl's mem functions ... not critical */
    }

    if (TlsLibInit() != TCL_OK) {
#if defined(OPENSSL_THREADS) && defined(TCL_THREADS)
    /* should we consider allocating mutexes? */
    num_locks = CRYPTO_num_locks();
    if (num_locks > CRYPTO_NUM_LOCKS) {
       Tcl_AppendResult(interp, "crypto num locks size error", NULL);
       return TCL_ERROR;
    }

    CRYPTO_set_locking_callback(CryptoThreadLockCallback);
    CRYPTO_set_id_callback(CryptoThreadIdCallback);
#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();

    /*
     * 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++) {
	    rnd_seed[i] = 1 + (char) (255.0 * rand()/(RAND_MAX+1.0));
	}
	RAND_seed(rnd_seed, sizeof(rnd_seed));
    } while (RAND_status() != 1);

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

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

 */

int
Tls_SafeInit (Tcl_Interp* interp)
{
    return Tls_Init (interp);
}


/*
 *------------------------------------------------------*
 *
 *	TlsLibInit --
 *
 *	------------------------------------------------*
 *	Initializes SSL library once per application
 *	------------------------------------------------*
 *
 *	Side effects:
 *		initilizes SSL library
 *
 *	Result:
 *		none
 *
 *------------------------------------------------------*
 */
static int
TlsLibInit ()
{
    int i;
    char rnd_seed[16] = "GrzSlplKqUdnnzP!";	/* 16 bytes */
#if defined(OPENSSL_THREADS) && defined(TCL_THREADS)
    size_t num_locks;
#endif
    int status=TCL_OK;

    if (!initialized) {
	Tcl_MutexLock(&init_mx);
	if (!initialized) {
	    initialized = 1;

	    if (CRYPTO_set_mem_functions((void *(*)(size_t))Tcl_Alloc,
					 (void *(*)(void *, size_t))Tcl_Realloc,
					 (void(*)(void *))Tcl_Free) == 0) {
	       /* Not using Tcl's mem functions ... not critical */
	    }

#if defined(OPENSSL_THREADS) && defined(TCL_THREADS)
	    /* should we consider allocating mutexes? */
	    num_locks = CRYPTO_num_locks();
	    if (num_locks > CRYPTO_NUM_LOCKS) {
		status=TCL_ERROR;
		goto done;
	    }

	    CRYPTO_set_locking_callback(CryptoThreadLockCallback);
	    CRYPTO_set_id_callback(CryptoThreadIdCallback);
#endif

	    if (SSL_library_init() != 1) {
	    	status=TCL_ERROR;
		goto done;
	    }
	    SSL_load_error_strings();
	    ERR_load_crypto_strings();

	    /*
	     * 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++) {
		    rnd_seed[i] = 1 + (char) (255.0 * rand()/(RAND_MAX+1.0));
		}
		RAND_seed(rnd_seed, sizeof(rnd_seed));
	    } while (RAND_status() != 1);
	}
    	done:

	Tcl_MutexUnlock(&init_mx);
    }
    return status;
}