* to enhance it to support full fileevent semantics.
 *
 * Also work done by the follow people provided the impetus to do this "right":
 *    tclSSL (Colin McCormack, Shared Technology)
 *    SSLtcl (Peter Antman)
 *
 */

/*
		tlsBIO.c				tlsIO.c
  +------+                         +-----+                                     +------+
  |      |Tcl_WriteRaw <-- BioWrite| SSL |BIO_write <-- TlsOutputProc <-- Write|      |
  |socket|      <encrypted>        | BIO |            <unencrypted>            | App  | 
  |      |Tcl_ReadRaw  -->  BioRead|     |BIO_Read  --> TlsInputProc  -->  Read|      |
  +------+                         +-----+                                     +------+
*/

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

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

/*
 *-----------------------------------------------------------------------------
 *
 * TlsCloseProc --
 *
 *	This procedure is invoked by the generic IO level to perform channel
 *	type specific cleanup when a SSL socket based channel is closed.
 *	Called by the generic I/O layer whenever the Tcl_Close() function is
 *	used.
 *
 * Results:
 *    0 if successful or POSIX error code if failed.
 *
 * Side effects:
 *    Closes the socket of the channel.
 *
 *-----------------------------------------------------------------------------
 */
static int TlsCloseProc(ClientData instanceData, Tcl_Interp *interp) {
    State *statePtr = (State *) instanceData;

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

    /* Flush any pending data */

    /* Send shutdown notification. Will return 0 while in process, then 1 when complete. */
    /* Closes the write direction of the connection; the read direction is closed by the peer. */
    /* Does not affect socket state. Don't call after fatal error. */
    if (statePtr->ssl != NULL && !(statePtr->flags & TLS_TCL_HANDSHAKE_FAILED)) {
	SSL_shutdown(statePtr->ssl);
    }

    /* Tls_Free calls Tls_Clean */
    Tcl_EventuallyFree((ClientData)statePtr, Tls_Free);
    return 0;
}

	}
	Tls_Error(statePtr, "Wait for failed handshake");
	return -1;
    }

    for (;;) {
	ERR_clear_error();
	BIO_clear_retry_flags(statePtr->bio);

	/* Not initialized yet! Also calls SSL_do_handshake(). */
	if (statePtr->flags & TLS_TCL_SERVER) {
	    dprintf("Calling SSL_accept()");
	    err = SSL_accept(statePtr->ssl);

	} else {
	    dprintf("Calling SSL_connect()");
	    err = SSL_connect(statePtr->ssl);
	}

	/* 1=successful, 0=not successful and shut down, <0=fatal error */
	if (err > 0) {
	    dprintf("Accept or connect was successful");

	    err = BIO_flush(statePtr->bio);
	    if (err <= 0) {
		dprintf("Flushing the lower layers failed, this will probably terminate this session");
	    }
	} else {
	    dprintf("Accept or connect failed");
	}

	/* Same as SSL_want, but also checks the error queue */
	rc = SSL_get_error(statePtr->ssl, err);
	backingError = ERR_get_error();
	if (rc != SSL_ERROR_NONE) {
	    dprintf("Got error: %i (rc = %i)", err, rc);
	    dprintf("Got error: %s", ERR_reason_error_string(backingError));
	}

	/* The retry flag is set by the BIO_set_retry_* functions */
	bioShouldRetry = BIO_should_retry(statePtr->bio);

	if (err <= 0) {
	    if (rc == SSL_ERROR_WANT_CONNECT || rc == SSL_ERROR_WANT_ACCEPT) {
		bioShouldRetry = 1;
	    } else if (rc == SSL_ERROR_WANT_READ) {
		bioShouldRetry = 1;
		statePtr->want |= TCL_READABLE;
	    } else if (rc == SSL_ERROR_WANT_WRITE) {
		bioShouldRetry = 1;
		statePtr->want |= TCL_WRITABLE;
	    } else if (BIO_should_retry(statePtr->bio)) {
		bioShouldRetry = 1;
	    } else if (rc == SSL_ERROR_SYSCALL && Tcl_GetErrno() == EAGAIN) {
		bioShouldRetry = 1;
	    }




	}

	if (bioShouldRetry) {
	    dprintf("The I/O did not complete -- but we should try it again");

	    if (statePtr->flags & TLS_TCL_ASYNC) {
		dprintf("Returning EAGAIN so that it can be retried later");

	dprintf("We have either completely established the session or completely failed it -- there is no more need to ever retry it though");
	break;
    }

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

	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");

		Tls_Error(statePtr, ERR_reason_error_string(backingError));
	    }

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

	case SSL_ERROR_ZERO_RETURN:
	    /* Peer has closed the connection by sending the close_notify alert. Can't read, but can write. */
	    /* Need to return an EOF, so channel is closed which will send an SSL_shutdown(). */
	    dprintf("SSL_ERROR_ZERO_RETURN: Connect returned an invalid value...");
	    *errorCodePtr = ECONNRESET;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    return -1;

	case SSL_ERROR_WANT_READ:
	    /* More data must be read from the underlying BIO layer in order to complete the actual SSL_*() operation.  */
	    dprintf("SSL_ERROR_WANT_READ");
	    BIO_set_retry_read(statePtr->bio);
	    *errorCodePtr = EAGAIN;
	    dprintf("ERR(%d, %d) ", rc, *errorCodePtr);
	    statePtr->want |= TCL_READABLE;
	    return -1;

	case SSL_ERROR_WANT_WRITE:
	    /* There is data in the SSL buffer that must be written to the underlying BIO in order to complete the SSL_*() operation. */
	    dprintf("SSL_ERROR_WANT_WRITE");
	    BIO_set_retry_write(statePtr->bio);
	    *errorCodePtr = EAGAIN;
	    dprintf("ERR(%d, %d) ", rc, *errorCodePtr);
	    statePtr->want |= TCL_WRITABLE;
	    return -1;

	case SSL_ERROR_WANT_CONNECT:
	    /* Connect would have blocked. */
	    dprintf("SSL_ERROR_WANT_CONNECT");
	    BIO_set_retry_special(statePtr->bio);
	    BIO_set_retry_reason(statePtr->bio, BIO_RR_CONNECT);
	    *errorCodePtr = EAGAIN;
	    dprintf("ERR(%d, %d) ", rc, *errorCodePtr);
	    return -1;

	case SSL_ERROR_WANT_ACCEPT:
	    /* Accept would have blocked */
	    dprintf("SSL_ERROR_WANT_ACCEPT");
	    BIO_set_retry_special(statePtr->bio);
	    BIO_set_retry_reason(statePtr->bio, BIO_RR_ACCEPT);
	    *errorCodePtr = EAGAIN;
	    dprintf("ERR(%d, %d) ", rc, *errorCodePtr);
	    return -1;

	case SSL_ERROR_WANT_X509_LOOKUP:
	    /* App callback set by SSL_CTX_set_client_cert_cb has asked to be called again */
	    /* The operation did not complete because an application callback set by SSL_CTX_set_client_cert_cb() has asked to be called again. */
	    dprintf("SSL_ERROR_WANT_X509_LOOKUP");
	    BIO_set_retry_special(statePtr->bio);
	    BIO_set_retry_reason(statePtr->bio, BIO_RR_SSL_X509_LOOKUP);
	    *errorCodePtr = EAGAIN;
	    dprintf("ERR(%d, %d) ", rc, *errorCodePtr);
	    return -1;

	case SSL_ERROR_WANT_ASYNC:
	    /* Used with flag SSL_MODE_ASYNC, op didn't complete because an async engine is still processing data */
	case SSL_ERROR_WANT_ASYNC_JOB:
	    /* The asynchronous job could not be started because there were no async jobs available in the pool. */
	case SSL_ERROR_WANT_CLIENT_HELLO_CB:
	    /* The operation did not complete because an application callback set by SSL_CTX_set_client_hello_cb() has asked to be called again. */
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
	case SSL_ERROR_WANT_RETRY_VERIFY:
	    /* The operation did not complete because a certificate verification callback has asked to be called again via SSL_set_retry_verify(3). */
#endif
	default:
	    /* The operation did not complete and should be retried later. */
	    dprintf("Operation did not complete, call function again later: %i", rc);
	    *errorCodePtr = EAGAIN;
	    dprintf("ERR(%d, %d) ", rc, *errorCodePtr);
	    Tls_Error(statePtr, "Operation did not complete, call function again later");

}

/*
 *-----------------------------------------------------------------------------
 *
 * TlsInputProc --
 *
 *	This procedure is invoked by the generic I/O layer to read data from

 *	the BIO whenever the Tcl_Read(), Tcl_ReadChars, Tcl_Gets, and
 *	Tcl_GetsObj functions are used. Equivalent to SSL_read_ex and SSL_read.
 *
 * Results:
 *	Returns the number of bytes read or -1 on error. Sets errorCodePtr to
 *	a POSIX error code if an error occurred, or 0 if none.
 *
 * Side effects:
 *    Reads input from the input device of the channel.
 *
 * Data is received in whole blocks known as records from the peer. A whole
 * record is processed (e.g. decrypted) in one go and is buffered by OpenSSL
 * until it is read by the application via a call to SSL_read. 
 *
 *-----------------------------------------------------------------------------
 */
static int TlsInputProc(ClientData instanceData, char *buf, int bufSize, int *errorCodePtr) {
    unsigned long backingError;
    State *statePtr = (State *) instanceData;
    int bytesRead, err;
    *errorCodePtr = 0;

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

    /* Skip if user verify callback is still running */
    if (statePtr->flags & TLS_TCL_CALLBACK) {
	dprintf("Callback is running, reading 0 bytes");
	return 0;
    }

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

	dprintf("Calling Tls_WaitForConnect");

	tlsConnect = Tls_WaitForConnect(statePtr, errorCodePtr, 0);
	if (tlsConnect < 0) {

     *
     * 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();
    BIO_clear_retry_flags(statePtr->bio);
    bytesRead = BIO_read(statePtr->bio, buf, bufSize);
    dprintf("BIO_read -> %d", bytesRead);

    /* Same as SSL_want, but also checks the error queue */
    err = SSL_get_error(statePtr->ssl, bytesRead);
    backingError = ERR_get_error();

    if (bytesRead <= 0) {
	/* The retry flag is set by the BIO_set_retry_* functions */
	if (BIO_should_retry(statePtr->bio)) {
	    dprintf("Read failed with code=%d, bytes read=%d: should retry", err, bytesRead);
	    /* Some docs imply we should redo the BIO_read now */
	} else {
	    dprintf("Read failed with code=%d, bytes read=%d: error condition", err, bytesRead);
	}

	dprintf("BIO is EOF %d", BIO_eof(statePtr->bio));
	
	/* These are the same as BIO_retry_type */
	if (BIO_should_read(statePtr->bio)) {
	    dprintf("BIO has insufficient data to read and return");
	    statePtr->want |= TCL_READABLE;
	}
	if (BIO_should_write(statePtr->bio)) {
	    dprintf("BIO has pending data to write");
	    statePtr->want |= TCL_WRITABLE;
	}
	if (BIO_should_io_special(statePtr->bio)) {
	    int reason = BIO_get_retry_reason(statePtr->bio);
	    dprintf("BIO has some special condition other than read or write: code=%d", reason);
	}
	dprintf("BIO has pending data to write");
    }

	    break;

	case SSL_ERROR_WANT_READ:
	    /* Op did not complete due to not enough data was available. Retry later. */
	    dprintf("Got SSL_ERROR_WANT_READ, mapping this to EAGAIN");
	    *errorCodePtr = EAGAIN;
	    bytesRead = -1;
	    statePtr->want |= TCL_READABLE;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_READ");
	    BIO_set_retry_read(statePtr->bio);
	    break;

	case SSL_ERROR_WANT_WRITE:
	    /* Op did not complete due to unable to sent all data to the BIO. Retry later. */
	    dprintf("Got SSL_ERROR_WANT_WRITE, mapping this to EAGAIN");
	    *errorCodePtr = EAGAIN;
	    bytesRead = -1;
	    statePtr->want |= TCL_WRITABLE;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_WRITE");
	    BIO_set_retry_write(statePtr->bio);
	    break;

	case SSL_ERROR_WANT_X509_LOOKUP:
	    /* Op didn't complete since callback set by SSL_CTX_set_client_cert_cb() asked to be called again */
	    dprintf("Got SSL_ERROR_WANT_X509_LOOKUP, mapping it to EAGAIN");
	    *errorCodePtr = EAGAIN;
	    bytesRead = -1;

		bytesRead = -1;
		Tls_Error(statePtr, ERR_reason_error_string(backingError));
	    }
	    break;

	case SSL_ERROR_ZERO_RETURN:
	    /* Peer has closed the connection by sending the close_notify alert. Can't read, but can write. */
	    /* Need to return an EOF, so channel is closed which will send an SSL_shutdown(). */
	    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_ASYNC:

}

/*
 *-----------------------------------------------------------------------------
 *
 * TlsOutputProc --
 *
 *	This procedure is invoked by the generic I/O layer to write data to the

 *	BIO whenever the the Tcl_Write(), Tcl_WriteChars, and Tcl_WriteObj 
 *	functions are used. Equivalent to SSL_write_ex and SSL_write.
 *
 * Results:
 *    Returns the number of bytes written or -1 on error. Sets errorCodePtr
 *    to a POSIX error code if an error occurred, or 0 if none.
 *
 * Side effects:
 *    Writes output on the output device of the channel.

	dprintf("Don't process output while callbacks are running");
	written = -1;
	*errorCodePtr = EAGAIN;
	return -1;
    }

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

	dprintf("Calling Tls_WaitForConnect");

	tlsConnect = Tls_WaitForConnect(statePtr, errorCodePtr, 1);
	if (tlsConnect < 0) {

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

    /* Same as SSL_want, but also checks the error queue */
    err = SSL_get_error(statePtr->ssl, written);
    backingError = ERR_get_error();

    if (written <= 0) {
	/* The retry flag is set by the BIO_set_retry_* functions */
	if (BIO_should_retry(statePtr->bio)) {
	    dprintf("Write failed with code %d, bytes written=%d: should retry", err, written);
	} else {
	    dprintf("Write failed with code %d, bytes written=%d: error condition", err, written);
	}

	/* These are the same as BIO_retry_type */
	if (BIO_should_read(statePtr->bio)) {
	    dprintf("BIO has insufficient data to read and return");
	}
	if (BIO_should_write(statePtr->bio)) {
	    dprintf("BIO has pending data to write");
	}

	    break;

	case SSL_ERROR_WANT_READ:
	    /* Op did not complete due to not enough data was available. Retry later. */
	    dprintf("Got SSL_ERROR_WANT_READ, mapping it to EAGAIN");
	    *errorCodePtr = EAGAIN;
	    written = -1;
	    statePtr->want |= TCL_READABLE;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_READ");
	    BIO_set_retry_read(statePtr->bio);
	    break;

	case SSL_ERROR_WANT_WRITE:
	    /* Op did not complete due to unable to sent all data to the BIO. Retry later. */
	    dprintf("Got SSL_ERROR_WANT_WRITE, mapping it to EAGAIN");
	    *errorCodePtr = EAGAIN;
	    written = -1;
	    statePtr->want |= TCL_WRITABLE;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_WRITE");
	    BIO_set_retry_write(statePtr->bio);
	    break;

	case SSL_ERROR_WANT_X509_LOOKUP:
	    /* Op didn't complete since callback set by SSL_CTX_set_client_cert_cb() asked to be called again */
	    dprintf("Got SSL_ERROR_WANT_X509_LOOKUP, mapping it to EAGAIN");
	    *errorCodePtr = EAGAIN;
	    written = -1;

		written = -1;
		Tls_Error(statePtr, ERR_reason_error_string(backingError));
	    }
	    break;

	case SSL_ERROR_ZERO_RETURN:
	    /* Peer has closed the connection by sending the close_notify alert. Can't read, but can write. */
	    /* Need to return an EOF, so channel is closed which will send an SSL_shutdown(). */
	    dprintf("Got SSL_ERROR_ZERO_RETURN, this means an EOF has been reached");
	    written = 0;
	    *errorCodePtr = 0;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    break;

	case SSL_ERROR_WANT_ASYNC:

{
    State *statePtr = (State *) instanceData;
    Tcl_Channel parent = Tls_GetParent(statePtr, TLS_TCL_FASTPATH);
    Tcl_DriverSetOptionProc *setOptionProc;

    dprintf("Called");

    /* Pass to parent */
    setOptionProc = Tcl_ChannelSetOptionProc(Tcl_GetChannelType(parent));
    if (setOptionProc != NULL) {
	return (*setOptionProc)(Tcl_GetChannelInstanceData(parent), interp, optionName, optionValue);
    }
    /*
     * Request for a specific option has to fail, we don't have any.
     */

{
    State *statePtr = (State *) instanceData;
    Tcl_Channel parent = Tls_GetParent(statePtr, TLS_TCL_FASTPATH);
    Tcl_DriverGetOptionProc *getOptionProc;

    dprintf("Called");

    /* Pass to parent */
    getOptionProc = Tcl_ChannelGetOptionProc(Tcl_GetChannelType(parent));
    if (getOptionProc != NULL) {
	return (*getOptionProc)(Tcl_GetChannelInstanceData(parent), interp, optionName, optionValue);
    } else if (optionName == (char*) NULL) {
	/*
	 * Request is query for all options, this is ok.
	 */

    /* Check for amount of data pending in BIO read buffer */
    if (BIO_pending(statePtr->bio)) {
	dprintf("[chan=%p] BIO readable", statePtr->self);

	mask |= TCL_READABLE;
    }

    /* Notify the generic IO layer that the mask events have occurred on the channel */
    dprintf("Notifying ourselves");
    Tcl_NotifyChannel(statePtr->self, mask);
    statePtr->want = 0;

    dprintf("Returning");

    return;

TlsWatchProc(ClientData instanceData,    /* The socket state. */
    int mask)			/* Events of interest; an OR-ed combination of
				 * TCL_READABLE, TCL_WRITABLE and TCL_EXCEPTION. */
{
    Tcl_Channel     parent;
    State *statePtr = (State *) instanceData;
    Tcl_DriverWatchProc *watchProc;
    int pending = 0;

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

    /* 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) {

     * to. But this transformation has no such interest. It just passes
     * the request down, unchanged.
     */
    dprintf("Registering our interest in the lower channel (chan=%p)", (void *) parent);
    watchProc = Tcl_ChannelWatchProc(Tcl_GetChannelType(parent));
    watchProc(Tcl_GetChannelInstanceData(parent), mask);

    /* Do we have any pending events */
    pending = (statePtr->want || \
	((mask & TCL_READABLE) && ((Tcl_InputBuffered(statePtr->self) > 0) || (BIO_ctrl_pending(statePtr->bio) > 0))) ||
	((mask & TCL_WRITABLE) && ((Tcl_OutputBuffered(statePtr->self) > 0) || (BIO_ctrl_wpending(statePtr->bio) > 0))));


    if (!(mask & TCL_READABLE) || pending == 0) {
	/* Remove timer, if any */

	if (statePtr->timer != (Tcl_TimerToken) NULL) {
	    dprintf("A timer was found, deleting it");
	    Tcl_DeleteTimerHandler(statePtr->timer);
	    statePtr->timer = (Tcl_TimerToken) NULL;
	}

    } else {
	/* Add timer, if none */
	if (statePtr->timer == (Tcl_TimerToken) NULL) {





	    dprintf("Creating a new timer since data appears to be waiting");
	    statePtr->timer = Tcl_CreateTimerHandler(TLS_TCL_DELAY, TlsChannelHandlerTimer, (ClientData) statePtr);
	}
    }
}

/*
 *-----------------------------------------------------------------------------
 *
 * TlsGetHandleProc --