])
if test "$tcltls_deterministic" = 'true'; then
	GEN_DH_PARAMS_ARGS='fallback'
else
	GEN_DH_PARAMS_ARGS=''
fi
AC_SUBST(GEN_DH_PARAMS_ARGS)

dnl Enable support for a debugging build
tcltls_debug='false'
AC_ARG_ENABLE([debug], AS_HELP_STRING([--enable-debug], [enable debugging parameters]), [
	if test "$enableval" = "yes"; then
		tcltls_debug='true'
	fi
])
if test "$tcltls_debug" = 'true'; then
	AC_DEFINE(TCLEXT_TCLTLS_DEBUG, [1], [Enable debugging build])
fi

AC_CHECK_TOOL([PKGCONFIG], [pkg-config], [false])

dnl XXX:TODO: Automatically determine the SSL library to use
dnl           defaulting to OpenSSL for compatibility reasons
if test "$tcltls_ssl_lib" = 'auto'; then
	tcltls_ssl_lib='openssl'

    int length;
    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("Verify: %d", ok);

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

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

    if (statePtr->bio) {
	/* This will call SSL_shutdown. Bug 1414045 */
	dprintf("BIO_free_all(%p)", statePtr->bio);
	BIO_free_all(statePtr->bio);
	statePtr->bio = NULL;
    }
    if (statePtr->ssl) {
	dprintf("SSL_free(%p)", statePtr->ssl);
	SSL_free(statePtr->ssl);
	statePtr->ssl = NULL;
    }
    if (statePtr->ctx) {
	SSL_CTX_free(statePtr->ctx);
	statePtr->ctx = NULL;
    }

    BIO *bio;
    CONST char *buf;
    int bufLen;
{
    Tcl_Channel chan = Tls_GetParent((State*)(bio->ptr));
    int ret;

    dprintf("BioWrite(%p, <buf>, %d) [%p]",
	    (void *) bio, bufLen, (void *) chan);

    if (channelTypeVersion == TLS_CHANNEL_VERSION_2) {
	ret = Tcl_WriteRaw(chan, buf, bufLen);
    } else {
	ret = Tcl_Write(chan, buf, bufLen);
    }

    dprintf("[%p] BioWrite(%d) -> %d [%d.%d]",
	    (void *) chan, bufLen, ret, Tcl_Eof(chan), Tcl_GetErrno());

    BIO_clear_flags(bio, BIO_FLAGS_WRITE|BIO_FLAGS_SHOULD_RETRY);

    if (ret == 0) {
	if (!Tcl_Eof(chan)) {
	    BIO_set_retry_write(bio);

    BIO *bio;
    char *buf;
    int bufLen;
{
    Tcl_Channel chan = Tls_GetParent((State*)bio->ptr);
    int ret = 0;

    dprintf("BioRead(%p, <buf>, %d) [%p]",
	    (void *) bio, bufLen, (void *) chan);

    if (buf == NULL) return 0;

    if (channelTypeVersion == TLS_CHANNEL_VERSION_2) {
	ret = Tcl_ReadRaw(chan, buf, bufLen);
    } else {
	ret = Tcl_Read(chan, buf, bufLen);
    }

    dprintf("[%p] BioRead(%d) -> %d [%d.%d]",
	    (void *) chan, bufLen, ret, Tcl_Eof(chan), Tcl_GetErrno());

    BIO_clear_flags(bio, BIO_FLAGS_READ|BIO_FLAGS_SHOULD_RETRY);

    if (ret == 0) {
	if (!Tcl_Eof(chan)) {
	    BIO_set_retry_read(bio);

    long num;
    void *ptr;
{
    Tcl_Channel chan = Tls_GetParent((State*)bio->ptr);
    long ret = 1;
    int *ip;

    dprintf("BioCtrl(%p, 0x%x, 0x%x, %p)",
	    (void *) bio, (unsigned int) cmd, (unsigned int) num,
	    (void *) ptr);

    switch (cmd) {
    case BIO_CTRL_RESET:
	num = 0;
    case BIO_C_FILE_SEEK:

    case BIO_CTRL_GET_CLOSE:
	ret = bio->shutdown;
	break;
    case BIO_CTRL_SET_CLOSE:
	bio->shutdown = (int)num;
	break;
    case BIO_CTRL_EOF:
	dprintf("BIO_CTRL_EOF");
	ret = Tcl_Eof(chan);
	break;
    case BIO_CTRL_PENDING:
	ret = (Tcl_InputBuffered(chan) ? 1 : 0);
	dprintf("BIO_CTRL_PENDING(%d)", (int) ret);
	break;
    case BIO_CTRL_WPENDING:
	ret = 0;
	break;
    case BIO_CTRL_DUP:
	break;
    case BIO_CTRL_FLUSH:
	dprintf("BIO_CTRL_FLUSH");
	if (channelTypeVersion == TLS_CHANNEL_VERSION_2) {
	    ret = ((Tcl_WriteRaw(chan, "", 0) >= 0) ? 1 : -1);
	} else {
	    ret = ((Tcl_Flush(chan) == TCL_OK) ? 1 : -1);
	}
	break;
    default:

 */
static int
TlsCloseProc(ClientData instanceData,	/* The socket to close. */
             Tcl_Interp *interp)	/* For error reporting - unused. */
{
    State *statePtr = (State *) instanceData;

    dprintf("TlsCloseProc(%p)", (void *) statePtr);

    if (channelTypeVersion == TLS_CHANNEL_VERSION_1) {
	/*
	 * Remove event handler to underlying channel, this could
	 * be because we are closing for real, or being "unstacked".
	 */

	int *errorCodePtr)		/* Where to store error code. */
{
    State *statePtr = (State *) instanceData;
    int bytesRead;			/* How many bytes were read? */

    *errorCodePtr = 0;

    dprintf("BIO_read(%d)", bufSize);

    if (statePtr->flags & TLS_TCL_CALLBACK) {
       /* don't process any bytes while verify callback is running */
       bytesRead = 0;
       goto input;
    }

     * Alternatively, we may want to handle the <0 return codes from
     * BIO_read specially (as advised in the RSA docs).  TLS's lower level BIO
     * functions play with the retry flags though, and this seems to work
     * correctly.  Similar fix in TlsOutputProc. - hobbs
     */
    ERR_clear_error();
    bytesRead = BIO_read(statePtr->bio, buf, bufSize);
    dprintf("BIO_read -> %d", bytesRead);

    if (bytesRead < 0) {
	int err = SSL_get_error(statePtr->ssl, bytesRead);

	if (err == SSL_ERROR_SSL) {
	    Tls_Error(statePtr, SSL_ERROR(statePtr->ssl, bytesRead));
	    *errorCodePtr = ECONNABORTED;
	} else if (BIO_should_retry(statePtr->bio)) {
	    dprintf("RE! ");
	    *errorCodePtr = EAGAIN;
	} else {
	    *errorCodePtr = Tcl_GetErrno();
	    if (*errorCodePtr == ECONNRESET) {
		/* Soft EOF */
		*errorCodePtr = 0;
		bytesRead = 0;
	    }
	}
    }
    input:
    dprintf("Input(%d) -> %d [%d]", bufSize, bytesRead, *errorCodePtr);
    return bytesRead;
}

/*
 *-------------------------------------------------------------------
 *
 * TlsOutputProc --

              int *errorCodePtr)	/* Where to store error code. */
{
    State *statePtr = (State *) instanceData;
    int written, err;

    *errorCodePtr = 0;

    dprintf("BIO_write(%p, %d)", (void *) statePtr, toWrite);

    if (statePtr->flags & TLS_TCL_CALLBACK) {
       /* don't process any bytes while verify callback is running */
       written = -1;
       *errorCodePtr = EAGAIN;
       goto output;
    }

    if (!SSL_is_init_finished(statePtr->ssl)) {
	written = Tls_WaitForConnect(statePtr, errorCodePtr);
	if (written <= 0) {
	    goto output;
	}
    }
    if (statePtr->flags & TLS_TCL_INIT) {
	statePtr->flags &= ~(TLS_TCL_INIT);
    }
    if (toWrite == 0) {
	dprintf("zero-write");
	BIO_flush(statePtr->bio);
	written = 0;
	goto output;
    } else {
	/*
	 * We need to clear the SSL error stack now because we sometimes reach
	 * this function with leftover errors in the stack.  If BIO_write
	 * returns -1 and intends EAGAIN, there is a leftover error, it will be
	 * misconstrued as an error, not EAGAIN.
	 *
	 * Alternatively, we may want to handle the <0 return codes from
	 * BIO_write specially (as advised in the RSA docs).  TLS's lower level
	 * BIO functions play with the retry flags though, and this seems to
	 * work correctly.  Similar fix in TlsInputProc. - hobbs
	 */
	ERR_clear_error();
	written = BIO_write(statePtr->bio, buf, toWrite);
	dprintf("BIO_write(%p, %d) -> [%d]",
		(void *) statePtr, toWrite, written);
    }
    if (written <= 0) {
	switch ((err = SSL_get_error(statePtr->ssl, written))) {
	    case SSL_ERROR_NONE:
		if (written < 0) {
		    written = 0;
		}
		break;
	    case SSL_ERROR_WANT_WRITE:
		dprintf(" write W BLOCK");
		break;
	    case SSL_ERROR_WANT_READ:
		dprintf(" write R BLOCK");
		break;
	    case SSL_ERROR_WANT_X509_LOOKUP:
		dprintf(" write X BLOCK");
		break;
	    case SSL_ERROR_ZERO_RETURN:
		dprintf(" closed");
		written = 0;
		break;
	    case SSL_ERROR_SYSCALL:
		*errorCodePtr = Tcl_GetErrno();
		dprintf(" [%d] syscall errr: %d",
			written, *errorCodePtr);
		written = -1;
		break;
	    case SSL_ERROR_SSL:
		Tls_Error(statePtr, SSL_ERROR(statePtr->ssl, written));
		*errorCodePtr = ECONNABORTED;
		written = -1;
		break;
	    default:
		dprintf(" unknown err: %d", err);
		break;
	}
    }
    output:
    dprintf("Output(%d) -> %d", toWrite, written);
    return written;
}

/*
 *-------------------------------------------------------------------
 *
 * TlsGetOptionProc --

TlsWatchProc(ClientData instanceData,	/* The socket state. */
             int mask)			/* Events of interest; an OR-ed
                                         * combination of TCL_READABLE,
                                         * TCL_WRITABLE and TCL_EXCEPTION. */
{
    State *statePtr = (State *) instanceData;

    dprintf("TlsWatchProc(0x%x)", mask);

    /* Pretend to be dead as long as the verify callback is running. 
     * Otherwise that callback could be invoked recursively. */
    if (statePtr->flags & TLS_TCL_CALLBACK) { return; }

    if (channelTypeVersion == TLS_CHANNEL_VERSION_2) {
	Tcl_Channel     downChan;

static void
TlsChannelHandler (clientData, mask)
    ClientData     clientData;
    int            mask;
{
    State *statePtr = (State *) clientData;

    dprintf("HANDLER(0x%x)", mask);
    Tcl_Preserve( (ClientData)statePtr);

    if (mask & TCL_READABLE) {
	BIO_set_flags(statePtr->p_bio, BIO_FLAGS_READ);
    } else {
	BIO_clear_flags(statePtr->p_bio, BIO_FLAGS_READ);
    }

int
Tls_WaitForConnect( statePtr, errorCodePtr)
    State *statePtr;
    int *errorCodePtr;		/* Where to store error code. */
{
    int err;

    dprintf("WaitForConnect(%p)", (void *) statePtr);

    if (statePtr->flags & TLS_TCL_HANDSHAKE_FAILED) {
        /*
         * We choose ECONNRESET over ECONNABORTED here because some server
         * side code, on the wiki for example, sets up a read handler that
         * does a read and if eof closes the channel. There is no catch/try
         * around the reads so exceptions will result in potentially many

		Tls_Error(statePtr,
			(char *)ERR_reason_error_string(ERR_get_error()));
                statePtr->flags |= TLS_TCL_HANDSHAKE_FAILED;
		*errorCodePtr = ECONNABORTED;
		return -1;
	    } else if (BIO_should_retry(statePtr->bio)) {
		if (statePtr->flags & TLS_TCL_ASYNC) {
		    dprintf("E! ");
		    *errorCodePtr = EAGAIN;
		    return -1;
		} else {
		    continue;
		}
	    } else if (err == 0) {
                if (Tcl_Eof(statePtr->self)) {
                    return 0;
                }
		dprintf("CR! ");
		*errorCodePtr = ECONNRESET;
		return -1;
	    }
	    if (statePtr->flags & TLS_TCL_SERVER) {
		err = SSL_get_verify_result(statePtr->ssl);
		if (err != X509_V_OK) {
		    Tls_Error(statePtr,
			    (char *)X509_verify_cert_error_string(err));
                    statePtr->flags |= TLS_TCL_HANDSHAKE_FAILED;
		    *errorCodePtr = ECONNABORTED;
		    return -1;
		}
	    }
	    *errorCodePtr = Tcl_GetErrno();
	    dprintf("ERR(%d, %d) ", rc, *errorCodePtr);
	    return -1;
	}
	dprintf("R0! ");
	return 1;
    }
}

Tcl_Channel
Tls_GetParent( statePtr )
    State *statePtr;

#ifndef ECONNABORTED
#define ECONNABORTED	130	/* Software caused connection abort */
#endif
#ifndef ECONNRESET
#define ECONNRESET	131	/* Connection reset by peer */
#endif

#ifdef TCLEXT_TCLTLS_DEBUG
#define dprintf(...) { fprintf(stderr, "%s:%i:", __func__, __LINE__); fprintf(stderr, __VA_ARGS__); fprintf(stderr, "\n"); }
#else
#define dprintf(...) if (0) { fprintf(stderr, __VA_ARGS__); }
#endif

#define SSL_ERROR(ssl,err)	\
    ((char*)ERR_reason_error_string((unsigned long)SSL_get_error((ssl),(err))))
/*
 * OpenSSL BIO Routines
 */