2 * Amanda, The Advanced Maryland Automatic Network Disk Archiver
3 * Copyright (c) 1999 University of Maryland at College Park
6 * Permission to use, copy, modify, distribute, and sell this software and its
7 * documentation for any purpose is hereby granted without fee, provided that
8 * the above copyright notice appear in all copies and that both that
9 * copyright notice and this permission notice appear in supporting
10 * documentation, and that the name of U.M. not be used in advertising or
11 * publicity pertaining to distribution of the software without specific,
12 * written prior permission. U.M. makes no representations about the
13 * suitability of this software for any purpose. It is provided "as is"
14 * without express or implied warranty.
16 * U.M. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL U.M.
18 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
19 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
20 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
21 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23 * Authors: the Amanda Development Team. Its members are listed in a
24 * file named AUTHORS, in the root directory of this distribution.
27 * $Id: security.h,v 1.17 2006/05/26 14:00:58 martinea Exp $
36 struct security_handle;
41 * The Security API consists of handles (also called connections), each of
42 * which represents a connection to a particular host. A handle is implemented
43 * by a driver. Each handle supports a packet-based communication protocol, as
44 * well as an arbitrary number of bidirectional tcp-like streams.
48 * This is a type that gets passed to the security_recvpkt() and
49 * security_connect() callbacks. It details what the status of this callback
53 S_OK, /* the pkt_t was received fine */
54 S_TIMEOUT, /* no pkt_t was received within the time specified in the
55 * timeout argument to security_recvpkt() */
56 S_ERROR, /* an error occurred during reception. Call security_geterror()
57 * for more information */
65 * This structure defines a security driver. This driver abstracts
66 * common security actions behind a set of function pointers. Macros
69 typedef struct security_driver {
72 * The name of this driver, eg, "BSD", "BSDTCP", "KRB5", etc... This is
73 * used by security_getdriver() to associate a name with a driver type.
78 * This is the implementation of security_connect(). It actually sets up
79 * the connection, and then returns a structure describing the connection.
80 * The first element of this structure MUST be a security_handle_t, because
81 * it will be cast to that after it is passed up to the caller.
83 * The first argument is the host to connect to. The second argument is a
84 * function to call when a connection is made. The third argument is passed
87 * The callback takes three arguments. The first is the caller supplied
88 * void pointer. The second is a newly allocated security handle. The third
89 * is a security_status_t flag indicating the success or failure of the
92 void (*connect)(const char *, char *(*)(char *, void *),
93 void (*)(void *, struct security_handle *, security_status_t),
97 * This form sets up a callback that returns new handles as they are
98 * received. It is passed the input and output file descriptors and a
99 * callback. The callback takes a security handle argument and also an
100 * initial packet received for that handle.
102 void (*accept)(const struct security_driver *, char *(*)(char *, void *),
103 int, int, void (*)(struct security_handle *, pkt_t *), void *);
105 /* get the remote hostname */
106 char *(*get_authenticated_peer_name)(struct security_handle *handle);
109 * Frees up handles allocated by the previous methods
111 void (*close)(void *);
114 * This transmits a packet after adding the security information
115 * Returns 0 on success, negative on error.
117 ssize_t (*sendpkt)(void *, pkt_t *);
120 * This creates an event in the event handler for receiving pkt_t's on a
121 * security_handle. The given callback will be called with the given arg
122 * when the driver determines that it has data for that handle. The last
123 * argument is a timeout, in seconds. This may be -1 to indicate no
124 * timeout. This method should assume that the caller will invoke
127 * If there was an error or timeout, this will be indicated in the status
130 * Only one recvpkt request can exist per handle.
132 void (*recvpkt)(void *, void (*)(void *, pkt_t *, security_status_t), void
136 * Cancel an outstanding recvpkt request on a handle. Drivers should allow
137 * this to be run even if no recvpkt was scheduled, or if one was
138 * previously cancelled.
140 void (*recvpkt_cancel)(void *);
143 * Get a stream given a security handle. This function returns a object
144 * describing the stream. The first member of this object MUST be a
145 * security_stream_t, because it will be cast to that.
147 void *(*stream_server)(void *);
150 * Accept a stream created by stream_server
152 int (*stream_accept)(void *);
155 * Get a stream and connect it to a remote given a security handle and a
156 * stream id. This function returns a object describing the stream. The
157 * first member of this object MUST be a security_stream_t, because it will
160 void *(*stream_client)(void *, int);
163 * Close a stream opened with stream_server or stream_client
165 void (*stream_close)(void *);
168 * Authenticate a stream.
170 int (*stream_auth)(void *);
173 * Return a numeric id for a stream. This is to be used by stream_client
174 * on the other end of the connection to connect to this stream.
176 int (*stream_id)(void *);
181 int (*stream_write)(void *, const void *, size_t);
184 * Read asyncronously from a stream. Only one request can exist
187 void (*stream_read)(void *, void (*)(void *, void *, ssize_t), void *);
190 * Read syncronously from a stream.
192 ssize_t (*stream_read_sync)(void *, void **);
195 * Cancel a stream read request
197 void (*stream_read_cancel)(void *);
199 void (*close_connection)(void *, char *);
201 int (*data_encrypt)(void *, void *, ssize_t, void **, ssize_t *);
202 int (*data_decrypt)(void *, void *, ssize_t, void **, ssize_t *);
205 /* Given a security type ("KRB4", "BSD", "SSH", etc), returns a pointer to that
206 * type's security_driver_t, or NULL if no driver exists. */
207 const security_driver_t *security_getdriver(const char *);
214 * This structure is a handle to a connection to a host for transmission
215 * of protocol packets (pkt_t's). The underlying security type defines
216 * the actual protocol and transport.
218 * This handle is reference counted so that it can be used inside of
219 * security streams after it has been closed by our callers.
221 typedef struct security_handle {
222 const security_driver_t *driver;
226 /* void security_connect(
227 * const security_driver_t *driver,
228 * const char *hostname,
229 * char *(*conf_fn)(char *, void *),
230 * void (*fn)(void *, security_handle_t *, security_status_t),
234 * Given a security driver, and a hostname, calls back with a security_handle_t
235 * that can be used to communicate with that host. The status arg to the
236 * callback is reflects the success of the request. Error messages can be had
237 * via security_geterror(). The conf_fn is used to determine configuration
238 * information, with its second argument being the datap. If conf_fn is NULL,
239 * no configuration information is available.
241 #define security_connect(driver, hostname, conf_fn, fn, arg, datap) \
242 (*(driver)->connect)(hostname, conf_fn, fn, arg, datap)
244 /* void security_accept(
245 * const security_driver_t *driver,
246 * char *(*conf_fn)(char *, void *),
249 * void (*fn)(security_handle_t *, pkt_t *),
252 * Given a security driver, an input file descriptor, and an output file
253 * descriptor, and a callback, when new connections are detected on the given
254 * file descriptors, the function is called with a newly created security
255 * handle and the initial packet received. This is amandad's interface for
256 * accepting incoming connections from the Amanda server. The file descriptors
257 * are typically 0 and 1 (stdin/stdout). This function uses the event
258 * interface, and only works properly when event_loop() is called later in the
261 #define security_accept(driver, conf_fn, in, out, fn, datap) \
262 (*(driver)->accept)(driver, conf_fn, in, out, fn, datap)
264 /* char *security_get_authenticated_peer_name(
265 * security_handle_t *handle);
267 * Returns the fully qualified, authenticated hostname of the peer, or
268 * "localhost" for a local system. The string is statically allocated and need
269 * not be freed. The string will never be NULL, but may be an empty string if
270 * the remote identity is not known, not defined, or could not be
273 #define security_get_authenticated_peer_name(handle) \
274 (*(handle)->driver->get_authenticated_peer_name)(handle)
276 /* Closes a security stream created by a security_connect() or
277 * security_accept() and frees up resources associated with it. */
278 void security_close(security_handle_t *);
280 /* ssize_t security_sendpkt(security_handle_t *, const pkt_t *);
282 * Transmits a pkt_t over a security handle. Returns 0 on success, or negative
283 * on error. A descriptive error message can be obtained via
284 * security_geterror(). */
285 #define security_sendpkt(handle, pkt) \
286 (*(handle)->driver->sendpkt)(handle, pkt)
288 /* void security_recvpkt(
289 * security_handle_t *handle,
290 * void (*fn)(void *, pkt_t *, security_status_t),
294 * Requests that when incoming packets arrive for this handle, the given
295 * function is called with the given argument, the received packet, and the
296 * status of the reception. If a packet does not arrive within the number of
297 * seconds specified in the 'timeout' argument, RECV_TIMEOUT is passed in the
298 * status argument of the timeout. On receive error, the callback's status
299 * argument will be set to RECV_ERROR. An error message can be retrieved via
300 * security_geterror(). On successful reception, RECV_OK will be passed in the
301 * status argument, and the pkt argument will point to a valid packet. This
302 * function uses the event interface. Callbacks will only be generated when
303 * event_loop() is called. */
304 #define security_recvpkt(handle, fn, arg, timeout) \
305 (*(handle)->driver->recvpkt)(handle, fn, arg, timeout)
307 /* void security_recvpkt_cancel(security_handle_t *);
309 * Cancels a previous recvpkt request for this handle. */
310 #define security_recvpkt_cancel(handle) \
311 (*(handle)->driver->recvpkt_cancel)(handle)
313 /* const char *security_geterror(security_handle_t *);
315 * Returns a descriptive error message for the last error condition on this
317 #define security_geterror(handle) ((handle)->error)
319 /* Sets the string that security_geterror() returns. For use by security
321 void security_seterror(security_handle_t *, const char *, ...)
324 /* Initializes a security_handle_t. This is meant to be called only by security
325 * drivers to initialize the common part of a newly allocated
326 * security_handle_t. */
327 void security_handleinit(security_handle_t *, const security_driver_t *);
334 * This structure is a handle to a stream connection to a host for
335 * transmission of random data such as dumps or index data.
337 typedef struct security_stream {
338 const security_driver_t *driver;
342 /* Initializes a security_stream_t. This is meant to be called only by security
343 * drivers to initialize the common part of a newly allocated
344 * security_stream_t. */
345 void security_streaminit(security_stream_t *, const security_driver_t *);
347 /* const char *security_stream_geterror(security_stream_t *);
349 * Returns a descriptive error message for the last error condition on this
351 #define security_stream_geterror(stream) ((stream)->error)
353 /* Sets the string that security_stream_geterror() returns. */
354 void security_stream_seterror(security_stream_t *, const char *, ...)
357 /* security_stream_t *security_stream_server(security_handle_t *);
359 * Creates the server end of a security stream, and will prepare to receive a
360 * connection from the host on the other end of the security handle passed.
361 * Returns a security_stream_t on success, and NULL on error. Error messages
362 * can be obtained by calling security_geterror() on the security handle
363 * associated with this stream. */
364 #define security_stream_server(handle) \
365 (*(handle)->driver->stream_server)(handle)
367 /* int security_stream_accept(security_stream_t *);
369 * Given a security stream created by security_stream_server, blocks until a
370 * connection is made from the remote end. After calling stream_server,
371 * stream_accept must be called on the stream before it is fully connected.
372 * Returns 0 on success, and -1 on error. Error messages can be obtained by
373 * calling security_stream_geterror().
375 #define security_stream_accept(stream) \
376 (*(stream)->driver->stream_accept)(stream)
378 /* security_stream_t *security_stream_client(security_handle_t *, int);
380 * Creates the client end of a security stream, and connects it to the machine
381 * on the other end of the security handle. The 'id' argument identifies which
382 * stream on the other end to connect to, and should have come from
383 * security_stream_id on the other end of the connection. Returns a
384 * security_stream_t on success, and NULL on error. Error messages can be
385 * obtained by calling security_geterror() on the security handle associated
386 * with this stream. */
387 #define security_stream_client(handle, id) \
388 (*(handle)->driver->stream_client)(handle, id)
390 /* Closes a security stream and frees up resources associated with it. */
391 void security_stream_close(security_stream_t *);
393 /* int security_stream_auth(security_stream_t *);
395 * Authenticate a connected security stream. This should be called by the
396 * target after security_stream_accept returns successfully, and by the client
397 * after security_stream_connect returns successfullly. Returns 0 on success,
398 * and -1 on error. Error messages can be obtained by calling
399 * security_stream_geterror().
401 #define security_stream_auth(stream) \
402 (*(stream)->driver->stream_auth)(stream)
404 /* int security_stream_id(security_stream_t *);
406 * Returns an identifier which can be used to connect to this security stream
407 * with security_stream_client(). Typical usage is for one end of a connection
408 * to create a stream with security_stream_server(), and then transmit the id
409 * for that stream to the other side. The other side will then connect to that
410 * id with security_stream_client(). */
411 #define security_stream_id(stream) \
412 (*(stream)->driver->stream_id)(stream)
414 /* int security_stream_write(security_stream_t *, const void *, size_t);
416 * Writes a chunk of data to the security stream. Returns 0 on success, or
417 * negative on error. Error messages can be obtained by calling
418 * security_stream_geterror().
420 #define security_stream_write(stream, buf, size) \
421 (*(stream)->driver->stream_write)(stream, buf, size)
423 /* void security_stream_read(
424 * security_stream_t *stream,
425 * void (*fn)(void *, void *, size_t),
428 * Requests that when data is ready to be read on this stream, the given
429 * function is called with the given arg, a buffer full of data, and the size
430 * of that buffer. On error, the bufsize will be negative. An error message can
431 * be retrieved by calling security_stream_geterror(). This function uses the
432 * event interface. Callbacks will only be generated while in event_loop(). */
433 #define security_stream_read(stream, fn, arg) \
434 (*(stream)->driver->stream_read)(stream, fn, arg)
436 /* void security_stream_read_sync(security_stream_t *, void **);
438 * Return a buffer of data read from the stream. This function will block until
439 * something can be read, but other event will be fired. A pointer to the data
440 * is returned in *buf and the size of the buffer is returned. On error, the
441 * size will be negative. An error message can be retrieved by calling
442 * security_stream_geterror(). This function uses the event interface. */
443 #define security_stream_read_sync(stream, buf) \
444 (*(stream)->driver->stream_read_sync)(stream, buf)
446 /* void security_stream_read_cancel(security_stream_t *);
448 * Cancels a previous read request. */
449 #define security_stream_read_cancel(stream) \
450 (*(stream)->driver->stream_read_cancel)(stream)
452 /* void security_close_connection(security_handle_t *, hostname *);
454 * Close a security handle, freeing associated resources. The hostname
455 * argument is ignored. */
456 #define security_close_connection(handle, hostname) \
457 (*(handle)->driver->close_connection)(handle, hostname)
459 #endif /* SECURITY_H */