*    SSLtcl (Peter Antman)
 *
 */

#include "tlsInt.h"
#include <errno.h>

/*
 * Forward declarations
 */
static void TlsChannelHandlerTimer(ClientData clientData);

/*
 *-------------------------------------------------------------------
 *
 * TlsBlockModeProc --
 *
 *    This procedure is invoked by the generic IO level
 *       to set blocking and nonblocking modes

    switch (rc) {
	case SSL_ERROR_NONE:
	    /* The TLS/SSL I/O operation completed */
	    dprintf("The connection is good");
	    *errorCodePtr = 0;
	    break;

	case SSL_ERROR_ZERO_RETURN:
	    /* The TLS/SSL peer has closed the connection for writing by sending the close_notify alert */
	    dprintf("SSL_ERROR_ZERO_RETURN: Connect returned an invalid value...");
	    *errorCodePtr = EINVAL;
	case SSL_ERROR_SSL:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL_ERROR_SSL: Got permanent fatal SSL error, aborting immediately");
	    if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    }
	    if (backingError != 0) {
		Tls_Error(statePtr, ERR_reason_error_string(backingError));
	    }
	    statePtr->flags |= TLS_TCL_HANDSHAKE_FAILED;
	    *errorCodePtr = ECONNABORTED;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    return -1;

	case SSL_ERROR_SYSCALL:
	    /* Some non-recoverable, fatal I/O error occurred */
	    dprintf("SSL_ERROR_SYSCALL");

	    if (backingError == 0 && err == 0) {
		dprintf("EOF reached")
		*errorCodePtr = ECONNRESET;
		Tls_Error(statePtr, "(unexpected) EOF reached");

	    } else if (backingError == 0 && err == -1) {
		dprintf("I/O error occurred (errno = %lu)", (unsigned long) Tcl_GetErrno());
		*errorCodePtr = Tcl_GetErrno();
		if (*errorCodePtr == ECONNRESET) {
		    *errorCodePtr = ECONNABORTED;
		}
		Tls_Error(statePtr, (char *) Tcl_ErrnoMsg(*errorCodePtr));
		Tls_Error(statePtr, Tcl_ErrnoMsg(*errorCodePtr));

	    } else {
		dprintf("I/O error occurred (backingError = %lu)", backingError);
		*errorCodePtr = Tcl_GetErrno();
		if (*errorCodePtr == ECONNRESET) {
		    *errorCodePtr = ECONNABORTED;
		}
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
		Tls_Error(statePtr, ERR_reason_error_string(backingError));
	    }

	    statePtr->flags |= TLS_TCL_HANDSHAKE_FAILED;
	    return -1;

	case SSL_ERROR_SSL:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL_ERROR_SSL: Got permanent fatal SSL error, aborting immediately");
	case SSL_ERROR_ZERO_RETURN:
	    /* The TLS/SSL peer has closed the connection for writing by sending the close_notify alert */
	    dprintf("SSL_ERROR_ZERO_RETURN: Connect returned an invalid value...");
	    if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, (char *) X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    }
	    if (backingError != 0) {
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    }
	    statePtr->flags |= TLS_TCL_HANDSHAKE_FAILED;
	    *errorCodePtr = ECONNABORTED;
	    *errorCodePtr = EINVAL;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    return -1;

	case SSL_ERROR_WANT_READ:
	case SSL_ERROR_WANT_WRITE:
	case SSL_ERROR_WANT_X509_LOOKUP:
	case SSL_ERROR_WANT_CONNECT:
	case SSL_ERROR_WANT_ACCEPT:

 *
 *-------------------------------------------------------------------
 */
static int TlsInputProc(ClientData instanceData, char *buf, int bufSize, int *errorCodePtr) {
    unsigned long backingError;
    State *statePtr = (State *) instanceData;
    int bytesRead;
    int tlsConnect;
    int err;

    *errorCodePtr = 0;

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

    /* Skip if user verify callback is still running */
    if (statePtr->flags & TLS_TCL_CALLBACK) {
	/* don't process any bytes while verify callback is running */
	dprintf("Callback is running, reading 0 bytes");
	return 0;
    }

    /* If not initialized, do connect */
    if (statePtr->flags & TLS_TCL_INIT) {
	int tlsConnect;

    dprintf("Calling Tls_WaitForConnect");
    tlsConnect = Tls_WaitForConnect(statePtr, errorCodePtr, 0);
    if (tlsConnect < 0) {
	dprintf("Got an error waiting to connect (tlsConnect = %i, *errorCodePtr = %i)", tlsConnect, *errorCodePtr);
	Tls_Error(statePtr, strerror(*errorCodePtr));
	dprintf("Calling Tls_WaitForConnect");

	tlsConnect = Tls_WaitForConnect(statePtr, errorCodePtr, 0);
	if (tlsConnect < 0) {
	    dprintf("Got an error waiting to connect (tlsConnect = %i, *errorCodePtr = %i)", tlsConnect, *errorCodePtr);
	    Tls_Error(statePtr, strerror(*errorCodePtr));

	bytesRead = -1;
	if (*errorCodePtr == ECONNRESET) {
	    dprintf("Got connection reset");
	    /* Soft EOF */
	    *errorCodePtr = 0;
	    bytesRead = 0;
	}
	return bytesRead;
	    bytesRead = -1;
	    if (*errorCodePtr == ECONNRESET) {
		dprintf("Got connection reset");
		/* Soft EOF */
		*errorCodePtr = 0;
		bytesRead = 0;
	    }
	    return bytesRead;
	}
    }

    /*
     * We need to clear the SSL error stack now because we sometimes reach
     * this function with leftover errors in the stack.  If BIO_read
     * returns -1 and intends EAGAIN, there is a leftover error, it will be
     * misconstrued as an error, not EAGAIN.

	    *errorCodePtr = EAGAIN;
	}
    }
#endif

    switch (err) {
	case SSL_ERROR_NONE:
	    dprintf("SSL_ERROR_NONE");
	    dprintBuffer(buf, bytesRead);
	    break;

	case SSL_ERROR_SSL:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL error, indicating that the connection has been aborted");
	    if (backingError != 0) {
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
		Tls_Error(statePtr, ERR_reason_error_string(backingError));
	    } else if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, (char *) X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
		Tls_Error(statePtr, X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    } else {
		Tls_Error(statePtr, "Unknown SSL error");
	    }
	    *errorCodePtr = ECONNABORTED;
	    bytesRead = -1;

#if OPENSSL_VERSION_NUMBER >= 0x30000000L
	    /* Unexpected EOF from the peer for OpenSSL 3.0+ */
	    if (ERR_GET_REASON(backingError) == SSL_R_UNEXPECTED_EOF_WHILE_READING) {
		dprintf("(Unexpected) EOF reached")
		*errorCodePtr = 0;
		bytesRead = 0;
		Tls_Error(statePtr, "EOF reached");
	    }    
	    }
#endif
	    break;

	case SSL_ERROR_WANT_READ:
	    dprintf("Got SSL_ERROR_WANT_READ, mapping this to EAGAIN");
	    bytesRead = -1;
	    *errorCodePtr = EAGAIN;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_READ");
	    break;

	case SSL_ERROR_SYSCALL:
	    /* Some non-recoverable, fatal I/O error occurred */
	    dprintf("SSL_ERROR_SYSCALL");

	    if (backingError == 0 && bytesRead == 0) {
		/* Unexpected EOF from the peer for OpenSSL 1.1 */
		dprintf("(Unexpected) EOF reached")
		*errorCodePtr = 0;
		bytesRead = 0;
		Tls_Error(statePtr, "EOF reached");

	    } else if (backingError == 0 && bytesRead == -1) {
		dprintf("I/O error occurred (errno = %lu)", (unsigned long) Tcl_GetErrno());
		*errorCodePtr = Tcl_GetErrno();
		bytesRead = -1;
		Tls_Error(statePtr, (char *) Tcl_ErrnoMsg(*errorCodePtr));
		Tls_Error(statePtr, Tcl_ErrnoMsg(*errorCodePtr));

	    } else {
		dprintf("I/O error occurred (backingError = %lu)", backingError);
		*errorCodePtr = Tcl_GetErrno();
		bytesRead = -1;
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
		Tls_Error(statePtr, ERR_reason_error_string(backingError));
	    }
	    break;

	case SSL_ERROR_ZERO_RETURN:
	    dprintf("Got SSL_ERROR_ZERO_RETURN, this means an EOF has been reached");
	    bytesRead = 0;
	    *errorCodePtr = 0;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    break;

	case SSL_ERROR_WANT_READ:
	    dprintf("Got SSL_ERROR_WANT_READ, mapping this to EAGAIN");
	    bytesRead = -1;
	    *errorCodePtr = EAGAIN;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_READ");
	    break;

	default:
	    dprintf("Unknown error (err = %i), mapping to EOF", err);
	    *errorCodePtr = 0;
	    bytesRead = 0;
	    Tls_Error(statePtr, "Unknown error");
	    break;
    }

 *
 *-------------------------------------------------------------------
 */
static int TlsOutputProc(ClientData instanceData, const char *buf, int toWrite, int *errorCodePtr) {
    unsigned long backingError;
    State *statePtr = (State *) instanceData;
    int written, err;
    int tlsConnect;

    *errorCodePtr = 0;

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

    /* Skip if user verify callback is still running */
    if (statePtr->flags & TLS_TCL_CALLBACK) {
	dprintf("Don't process output while callbacks are running");
	written = -1;
	*errorCodePtr = EAGAIN;
	return -1;
    }

    /* If not initialized, do connect */
    if (statePtr->flags & TLS_TCL_INIT) {
	int tlsConnect;

    dprintf("Calling Tls_WaitForConnect");
    tlsConnect = Tls_WaitForConnect(statePtr, errorCodePtr, 1);
    if (tlsConnect < 0) {
	dprintf("Got an error waiting to connect (tlsConnect = %i, *errorCodePtr = %i)", tlsConnect, *errorCodePtr);
	Tls_Error(statePtr, strerror(*errorCodePtr));
	dprintf("Calling Tls_WaitForConnect");

	tlsConnect = Tls_WaitForConnect(statePtr, errorCodePtr, 1);
	if (tlsConnect < 0) {
	    dprintf("Got an error waiting to connect (tlsConnect = %i, *errorCodePtr = %i)", tlsConnect, *errorCodePtr);
	    Tls_Error(statePtr, strerror(*errorCodePtr));

	written = -1;
	if (*errorCodePtr == ECONNRESET) {
	    dprintf("Got connection reset");
	    /* Soft EOF */
	    *errorCodePtr = 0;
	    written = 0;
	}
	return written;
	    written = -1;
	    if (*errorCodePtr == ECONNRESET) {
		dprintf("Got connection reset");
		/* Soft EOF */
		*errorCodePtr = 0;
		written = 0;
	    }
	    return written;
	}
    }

    if (toWrite == 0) {
	dprintf("zero-write");
	err = BIO_flush(statePtr->bio);

	if (err <= 0) {

    dprintf("BIO_write(%p, %d) -> [%d]", (void *) statePtr, toWrite, written);

    err = SSL_get_error(statePtr->ssl, written);
    backingError = ERR_get_error();

    switch (err) {
	case SSL_ERROR_NONE:
	    dprintf("SSL_ERROR_NONE");
	    if (written < 0) {
		written = 0;
	    }
	    break;

	case SSL_ERROR_SSL:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL error, indicating that the connection has been aborted");
	    if (backingError != 0) {
		Tls_Error(statePtr, ERR_reason_error_string(backingError));
	    } else if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    } else {
		Tls_Error(statePtr, "Unknown SSL error");
	    }
	    *errorCodePtr = ECONNABORTED;
	    written = -1;
	    break;

	case SSL_ERROR_WANT_READ:
	    dprintf(" write R BLOCK");
	    Tls_Error(statePtr, "SSL_ERROR_WANT_READ");
	    break;

	case SSL_ERROR_WANT_WRITE:
	    dprintf("Got SSL_ERROR_WANT_WRITE, mapping it to EAGAIN");
	    *errorCodePtr = EAGAIN;
	    written = -1;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_WRITE");
	    break;

	case SSL_ERROR_WANT_READ:
	    dprintf(" write R BLOCK");
	    Tls_Error(statePtr, "SSL_ERROR_WANT_READ");
	    break;

	case SSL_ERROR_WANT_X509_LOOKUP:
	    dprintf(" write X BLOCK");
	    Tls_Error(statePtr, "SSL_ERROR_WANT_X509_LOOKUP");
	    break;

	case SSL_ERROR_ZERO_RETURN:
	    dprintf(" closed");
	    written = 0;
	    *errorCodePtr = 0;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    break;

	case SSL_ERROR_SYSCALL:
	    /* Some non-recoverable, fatal I/O error occurred */
	    dprintf("SSL_ERROR_SYSCALL");

	    if (backingError == 0 && written == 0) {
		dprintf("EOF reached")
		*errorCodePtr = 0;
		written = 0;
		Tls_Error(statePtr, "EOF reached");

	    } else if (backingError == 0 && written == -1) {
		dprintf("I/O error occurred (errno = %lu)", (unsigned long) Tcl_GetErrno());
		*errorCodePtr = Tcl_GetErrno();
		written = -1;
		Tls_Error(statePtr, (char *) Tcl_ErrnoMsg(*errorCodePtr));
		Tls_Error(statePtr, Tcl_ErrnoMsg(*errorCodePtr));

	    } else {
		dprintf("I/O error occurred (backingError = %lu)", backingError);
		*errorCodePtr = Tcl_GetErrno();
		written = -1;
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
		Tls_Error(statePtr, ERR_reason_error_string(backingError));
	    }
	    break;

	case SSL_ERROR_SSL:
	case SSL_ERROR_ZERO_RETURN:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL error, indicating that the connection has been aborted");
	    if (backingError != 0) {
	    dprintf(" closed");
	    written = 0;
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    } else if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, (char *) X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    } else {
		Tls_Error(statePtr, "Unknown SSL error");
	    }
	    *errorCodePtr = ECONNABORTED;
	    *errorCodePtr = 0;
	    written = -1;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    break;

	default:
	    dprintf("unknown error: %d", err);
	    Tls_Error(statePtr, "Unknown error");
	    break;
    }

    dprintf("Output(%d) -> %d", toWrite, written);
    return written;
}

/*
 *-------------------------------------------------------------------
 *
 * Tls_GetParent --
 *
 *    Get parent for stacked channel.
 *
 * Results:
 *    Tcl_Channel or NULL if none.
 *
 *-------------------------------------------------------------------
 */
Tcl_Channel Tls_GetParent(State *statePtr, int maskFlags) {
    dprintf("Requested to get parent of channel %p", statePtr->self);

    if ((statePtr->flags & ~maskFlags) & TLS_TCL_FASTPATH) {
	dprintf("Asked to get the parent channel while we are using FastPath -- returning NULL");
	return NULL;
    }
    return Tcl_GetStackedChannel(statePtr->self);
}

/*
 *-------------------------------------------------------------------
 *
 * TlsSetOptionProc --
 *
 *    Sets an option value for a SSL socket based channel, or a

TlsSetOptionProc(ClientData instanceData,    /* Socket state. */
    Tcl_Interp *interp,		/* For errors - can be NULL. */
    const char *optionName,	/* Name of the option to set the value for, or
				 * NULL to get all options and their values. */
    const char *optionValue)	/* Value for option. */
{
    State *statePtr = (State *) instanceData;

    Tcl_Channel downChan = Tls_GetParent(statePtr, TLS_TCL_FASTPATH);
    Tcl_DriverSetOptionProc *setOptionProc;

    dprintf("Called");

    setOptionProc = Tcl_ChannelSetOptionProc(Tcl_GetChannelType(downChan));
    if (setOptionProc != NULL) {
	return (*setOptionProc)(Tcl_GetChannelInstanceData(downChan), interp, optionName, optionValue);
    } else if (optionName == (char*) NULL) {
	/*
	 * Request is query for all options, this is ok.

TlsGetOptionProc(ClientData instanceData,    /* Socket state. */
    Tcl_Interp *interp,		/* For errors - can be NULL. */
    const char *optionName,	/* Name of the option to retrieve the value for, or
				 * NULL to get all options and their values. */
    Tcl_DString *optionValue)	/* Where to store the computed value initialized by caller. */
{
    State *statePtr = (State *) instanceData;

    Tcl_Channel downChan = Tls_GetParent(statePtr, TLS_TCL_FASTPATH);
    Tcl_DriverGetOptionProc *getOptionProc;

    dprintf("Called");

    getOptionProc = Tcl_ChannelGetOptionProc(Tcl_GetChannelType(downChan));
    if (getOptionProc != NULL) {
	return (*getOptionProc)(Tcl_GetChannelInstanceData(downChan), interp, optionName, optionValue);
    } else if (optionName == (char*) NULL) {
	/*
	 * Request is query for all options, this is ok.
	 */
	return TCL_OK;
    }
    /*
     * Request for a specific option has to fail, we don't have any.
     */
    return Tcl_BadChannelOption(interp, optionName, "");
}

/*
 *------------------------------------------------------*
 *
 *    TlsChannelHandlerTimer --
 *
 *    ------------------------------------------------*
 *    Called by the notifier (-> timer) to flush out
 *    information waiting in channel buffers.
 *    ------------------------------------------------*
 *
 *    Side effects:
 *        As of 'TlsChannelHandler'.
 *
 *    Result:
 *        None.
 *
 *------------------------------------------------------*
 */
static void TlsChannelHandlerTimer(ClientData clientData) {
    State *statePtr = (State *) clientData;
    int mask = 0;

    dprintf("Called");

    statePtr->timer = (Tcl_TimerToken) NULL;

    if (BIO_wpending(statePtr->bio)) {
	dprintf("[chan=%p] BIO writable", statePtr->self);

	mask |= TCL_WRITABLE;
    }

    if (BIO_pending(statePtr->bio)) {
	dprintf("[chan=%p] BIO readable", statePtr->self);

	mask |= TCL_READABLE;
    }

    dprintf("Notifying ourselves");
    Tcl_NotifyChannel(statePtr->self, mask);

    dprintf("Returning");

    return;
}

/*
 *-------------------------------------------------------------------
 *
 * TlsWatchProc --
 *
 *    Initialize the notifier to watch Tcl_Files from this channel.

 *-------------------------------------------------------------------
 */
static int TlsNotifyProc(ClientData instanceData,    /* Socket state. */
    int mask)			/* type of event that occurred:
				 * OR-ed combination of TCL_READABLE or TCL_WRITABLE */
{
    State *statePtr = (State *) instanceData;
    int errorCode;
    int errorCode = 0;

    dprintf("Called");

    /*
     * An event occurred in the underlying channel.  This
     * transformation doesn't process such events thus returns the
     * incoming mask unchanged.
     */
    if (statePtr->timer != (Tcl_TimerToken) NULL) {
	/*
	 * Delete an existing timer. It was not fired, yet we are
	 * here, so the channel below generated such an event and we
	 * don't have to. The renewal of the interest after the
	 * execution of channel handlers will eventually cause us to
	 * recreate the timer (in WatchProc).
	 */
	Tcl_DeleteTimerHandler(statePtr->timer);
	statePtr->timer = (Tcl_TimerToken) NULL;
    }

    /* Skip if user verify callback is still running */
    if (statePtr->flags & TLS_TCL_CALLBACK) {
	dprintf("Returning 0 due to callback");
	dprintf("Callback is on-going, returning failed");
	return 0;
    }

    /* If not initialized, do connect */
    if (statePtr->flags & TLS_TCL_INIT) {
    dprintf("Calling Tls_WaitForConnect");
	dprintf("Calling Tls_WaitForConnect");
    errorCode = 0;
    if (Tls_WaitForConnect(statePtr, &errorCode, 1) < 0) {
	Tls_Error(statePtr, strerror(errorCode));
	if (errorCode == EAGAIN) {
	    dprintf("Async flag could be set (didn't check) and errorCode == EAGAIN:  Returning 0");
	if (Tls_WaitForConnect(statePtr, &errorCode, 1) < 0) {
	    Tls_Error(statePtr, strerror(errorCode));
	    if (errorCode == EAGAIN) {
		dprintf("Async flag could be set (didn't check) and errorCode == EAGAIN:  Returning failed");

	    return 0;
	}
		return 0;
	    }

	dprintf("Tls_WaitForConnect returned an error");
	    dprintf("Tls_WaitForConnect returned an error");
	}
    }

    dprintf("Returning %i", mask);

    return mask;
}

/*
 *------------------------------------------------------*
 *
 *    TlsChannelHandlerTimer --
 *
 *    ------------------------------------------------*
 *    Called by the notifier (-> timer) to flush out
 *    information waiting in channel buffers.
 *    ------------------------------------------------*
 *
 *    Side effects:
 *        As of 'TlsChannelHandler'.
 *
 *    Result:
 *        None.
 *
 *------------------------------------------------------*
 */
static void TlsChannelHandlerTimer(ClientData clientData) {
    State *statePtr = (State *) clientData;
    int mask = 0;

    dprintf("Called");

    statePtr->timer = (Tcl_TimerToken) NULL;

    if (BIO_wpending(statePtr->bio)) {
	dprintf("[chan=%p] BIO writable", statePtr->self);

	mask |= TCL_WRITABLE;
    }

    if (BIO_pending(statePtr->bio)) {
	dprintf("[chan=%p] BIO readable", statePtr->self);

	mask |= TCL_READABLE;
    }

    dprintf("Notifying ourselves");
    Tcl_NotifyChannel(statePtr->self, mask);

    dprintf("Returning");

    return;
}

Tcl_Channel Tls_GetParent(State *statePtr, int maskFlags) {
    dprintf("Requested to get parent of channel %p", statePtr->self);

    if ((statePtr->flags & ~maskFlags) & TLS_TCL_FASTPATH) {
	dprintf("Asked to get the parent channel while we are using FastPath -- returning NULL");
	return NULL;
    }
    return Tcl_GetStackedChannel(statePtr->self);
}

/*
 *-------------------------------------------------------------------
 *
 * Tls_ChannelType --
 *
 *    Return the correct TLS channel driver info
 *