xref: /illumos-gate/usr/src/uts/common/gssapi/mechs/dummy/dmech.c (revision 4eaa471005973e11a6110b69fe990530b3b95a38)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * A module that implements a dummy security mechanism.
31  * It's mainly used to test GSS-API application. Multiple tokens
32  * exchanged during security context establishment can be
33  * specified through dummy_mech.conf located in /etc.
34  */
35 
36 char _depends_on[] = "misc/kgssapi";
37 
38 #include <sys/types.h>
39 #include <sys/modctl.h>
40 #include <sys/errno.h>
41 #include <gssapiP_dummy.h>
42 #include <gssapi_err_generic.h>
43 #include <mechglueP.h>
44 #include <gssapi/kgssapi_defs.h>
45 #include <sys/debug.h>
46 
47 #ifdef DUMMY_MECH_DEBUG
48 /*
49  * Kernel kgssd module debugging aid. The global variable "dummy_mech_log"
50  * is a bit mask which allows various types of debugging messages
51  * to be printed out.
52  *
53  *       dummy_mech_log & 1  will cause actual failures to be printed.
54  *       dummy_mech_log & 2  will cause informational messages to be
55  *                       printed on the client side of kgssd.
56  *       dummy_mech_log & 4  will cause informational messages to be
57  *                       printed on the server side of kgssd.
58  *       dummy_mech_log & 8  will cause informational messages to be
59  *                       printed on both client and server side of kgssd.
60  */
61 
62 uint_t dummy_mech_log = 1;
63 #endif
64 
65 /* Local defines */
66 #define	MAGIC_TOKEN_NUMBER 12345
67 /* private routines for dummy_mechanism */
68 static gss_buffer_desc make_dummy_token_msg(void *data, int datalen);
69 
70 static int der_length_size(int);
71 
72 static void der_write_length(unsigned char **, int);
73 static int der_read_length(unsigned char **, int *);
74 static int g_token_size(gss_OID mech, unsigned int body_size);
75 static void g_make_token_header(gss_OID mech, int body_size,
76 				unsigned char **buf, int tok_type);
77 static int g_verify_token_header(gss_OID mech, int *body_size,
78 				unsigned char **buf_in, int tok_type,
79 				int toksize);
80 
81 /* private global variables */
82 static int dummy_token_nums;
83 
84 /*
85  * This OID:
86  * { iso(1) org(3) internet(6) dod(1) private(4) enterprises(1) sun(42)
87  * products(2) gssapi(26) mechtypes(1) dummy(2) }
88  */
89 
90 static struct gss_config dummy_mechanism =
91 	{{10, "\053\006\001\004\001\052\002\032\001\002"},
92 	NULL,	/* context */
93 	NULL,	/* next */
94 	TRUE,	/* uses_kmod */
95 /* EXPORT DELETE START */ /* CRYPT DELETE START */
96 	dummy_gss_unseal,
97 /* EXPORT DELETE END */ /* CRYPT DELETE END */
98 	dummy_gss_delete_sec_context,
99 /* EXPORT DELETE START */ /* CRYPT DELETE START */
100 	dummy_gss_seal,
101 /* EXPORT DELETE END */ /* CRYPT DELETE END */
102 	dummy_gss_import_sec_context,
103 /* EXPORT DELETE START */
104 /* CRYPT DELETE START */
105 #if 0
106 /* CRYPT DELETE END */
107 	dummy_gss_seal,
108 	dummy_gss_unseal,
109 /* CRYPT DELETE START */
110 #endif
111 /* CRYPT DELETE END */
112 /* EXPORT DELETE END */
113 	dummy_gss_sign,
114 	dummy_gss_verify
115 };
116 
117 static gss_mechanism
118 gss_mech_initialize()
119 {
120 	dprintf("Entering gss_mech_initialize\n");
121 
122 	if (dummy_token_nums == 0)
123 		dummy_token_nums = 1;
124 
125 	dprintf("Leaving gss_mech_initialize\n");
126 	return (&dummy_mechanism);
127 }
128 
129 /*
130  * Clean up after a failed mod_install()
131  */
132 static void
133 gss_mech_fini()
134 {
135 	/* Nothing to do */
136 }
137 
138 
139 /*
140  * Module linkage information for the kernel.
141  */
142 extern struct mod_ops mod_miscops;
143 
144 static struct modlmisc modlmisc = {
145 	&mod_miscops, "in-kernel dummy GSS mechanism"
146 };
147 
148 static struct modlinkage modlinkage = {
149 	MODREV_1,
150 	(void *)&modlmisc,
151 	NULL
152 };
153 
154 static int dummy_fini_code = EBUSY;
155 
156 int
157 _init()
158 {
159 	int retval;
160 	gss_mechanism mech, tmp;
161 
162 	mech = gss_mech_initialize();
163 
164 	mutex_enter(&__kgss_mech_lock);
165 	tmp = __kgss_get_mechanism(&mech->mech_type);
166 	if (tmp != NULL) {
167 		DUMMY_MECH_LOG0(8,
168 			"dummy GSS mechanism: mechanism already in table.\n");
169 		if (tmp->uses_kmod == TRUE) {
170 			DUMMY_MECH_LOG0(8, "dummy GSS mechanism: mechanism "
171 				"table supports kernel operations!\n");
172 		}
173 		/*
174 		 * keep us loaded, but let us be unloadable. This
175 		 * will give the developer time to trouble shoot
176 		 */
177 		dummy_fini_code = 0;
178 	} else {
179 		__kgss_add_mechanism(mech);
180 		ASSERT(__kgss_get_mechanism(&mech->mech_type) == mech);
181 	}
182 	mutex_exit(&__kgss_mech_lock);
183 
184 	if ((retval = mod_install(&modlinkage)) != 0)
185 		gss_mech_fini();	/* clean up */
186 
187 	return (retval);
188 }
189 
190 int
191 _fini()
192 {
193 	int ret = dummy_fini_code;
194 
195 	if (ret == 0) {
196 		ret = (mod_remove(&modlinkage));
197 	}
198 	return (ret);
199 }
200 
201 int
202 _info(struct modinfo *modinfop)
203 {
204 	return (mod_info(&modlinkage, modinfop));
205 }
206 
207 
208 /*ARGSUSED*/
209 static OM_uint32
210 dummy_gss_sign(context, minor_status, context_handle,
211 		qop_req, message_buffer, message_token,
212 		gssd_ctx_verifier)
213 	void *context;
214 	OM_uint32 *minor_status;
215 	gss_ctx_id_t context_handle;
216 	int qop_req;
217 	gss_buffer_t message_buffer;
218 	gss_buffer_t message_token;
219 	OM_uint32 gssd_ctx_verifier;
220 {
221 	dummy_gss_ctx_id_rec	*ctx;
222 	char token_string[] = "dummy_gss_sign";
223 
224 	dprintf("Entering gss_sign\n");
225 
226 	if (context_handle == GSS_C_NO_CONTEXT)
227 		return (GSS_S_NO_CONTEXT);
228 	ctx = (dummy_gss_ctx_id_rec *) context_handle;
229 	ASSERT(ctx->established == 1);
230 	ASSERT(ctx->token_number == MAGIC_TOKEN_NUMBER);
231 
232 	*message_token = make_dummy_token_msg(
233 				token_string, strlen(token_string));
234 
235 	dprintf("Leaving gss_sign\n");
236 	return (GSS_S_COMPLETE);
237 }
238 
239 /*ARGSUSED*/
240 static OM_uint32
241 	dummy_gss_verify(context, minor_status, context_handle,
242 		message_buffer, token_buffer, qop_state,
243 		gssd_ctx_verifier)
244 	void *context;
245 	OM_uint32 *minor_status;
246 	gss_ctx_id_t context_handle;
247 	gss_buffer_t message_buffer;
248 	gss_buffer_t token_buffer;
249 	int *qop_state;
250 	OM_uint32 gssd_ctx_verifier;
251 {
252 	unsigned char *ptr;
253 	int bodysize;
254 	int err;
255 	dummy_gss_ctx_id_rec	*ctx;
256 
257 	dprintf("Entering gss_verify\n");
258 
259 	if (context_handle == GSS_C_NO_CONTEXT)
260 		return (GSS_S_NO_CONTEXT);
261 
262 	ctx = (dummy_gss_ctx_id_rec *) context_handle;
263 	ASSERT(ctx->established == 1);
264 	ASSERT(ctx->token_number == MAGIC_TOKEN_NUMBER);
265 	/* Check for defective input token. */
266 
267 	ptr = (unsigned char *) token_buffer->value;
268 	if (err = g_verify_token_header((gss_OID)gss_mech_dummy, &bodysize,
269 					&ptr, 0,
270 					token_buffer->length)) {
271 		*minor_status = err;
272 		return (GSS_S_DEFECTIVE_TOKEN);
273 	}
274 
275 	*qop_state = GSS_C_QOP_DEFAULT;
276 
277 	dprintf("Leaving gss_verify\n");
278 	return (GSS_S_COMPLETE);
279 }
280 
281 /* EXPORT DELETE START */
282 /*ARGSUSED*/
283 static OM_uint32
284 dummy_gss_seal(context, minor_status, context_handle, conf_req_flag,
285 		qop_req, input_message_buffer, conf_state,
286 		output_message_buffer, gssd_ctx_verifier)
287 	void *context;
288 	OM_uint32 *minor_status;
289 	gss_ctx_id_t context_handle;
290 	int conf_req_flag;
291 	int qop_req;
292 	gss_buffer_t input_message_buffer;
293 	int *conf_state;
294 	gss_buffer_t output_message_buffer;
295 	OM_uint32 gssd_ctx_verifier;
296 {
297 	gss_buffer_desc	output;
298 	dummy_gss_ctx_id_rec	*ctx;
299 	dprintf("Entering gss_seal\n");
300 
301 	if (context_handle == GSS_C_NO_CONTEXT)
302 		return (GSS_S_NO_CONTEXT);
303 	ctx = (dummy_gss_ctx_id_rec *) context_handle;
304 	ASSERT(ctx->established == 1);
305 	ASSERT(ctx->token_number == MAGIC_TOKEN_NUMBER);
306 	/* Copy the input message to output message */
307 	output = make_dummy_token_msg(
308 		input_message_buffer->value, input_message_buffer->length);
309 
310 	if (conf_state)
311 		*conf_state = 1;
312 
313 	*output_message_buffer = output;
314 
315 	dprintf("Leaving gss_seal\n");
316 	return (GSS_S_COMPLETE);
317 }
318 
319 /*ARGSUSED*/
320 static OM_uint32
321 dummy_gss_unseal(context, minor_status, context_handle,
322 		input_message_buffer, output_message_buffer,
323 		conf_state, qop_state, gssd_ctx_verifier)
324 	void *context;
325 	OM_uint32 *minor_status;
326 	gss_ctx_id_t context_handle;
327 	gss_buffer_t input_message_buffer;
328 	gss_buffer_t output_message_buffer;
329 	int *conf_state;
330 	int *qop_state;
331 	OM_uint32 gssd_ctx_verifier;
332 {
333 	gss_buffer_desc output;
334 	dummy_gss_ctx_id_rec	*ctx;
335 	unsigned char *ptr;
336 	int bodysize;
337 	int err;
338 
339 	dprintf("Entering gss_unseal\n");
340 
341 	if (context_handle == GSS_C_NO_CONTEXT)
342 		return (GSS_S_NO_CONTEXT);
343 
344 	ctx = (dummy_gss_ctx_id_rec *) context_handle;
345 	ASSERT(ctx->established == 1);
346 	ASSERT(ctx->token_number == MAGIC_TOKEN_NUMBER);
347 
348 	ptr = (unsigned char *) input_message_buffer->value;
349 	if (err = g_verify_token_header((gss_OID)gss_mech_dummy, &bodysize,
350 					&ptr, 0,
351 					input_message_buffer->length)) {
352 		*minor_status = err;
353 		return (GSS_S_DEFECTIVE_TOKEN);
354 	}
355 	output.length = bodysize;
356 	output.value = (void *)MALLOC(output.length);
357 	(void) memcpy(output.value, ptr, output.length);
358 
359 	*output_message_buffer = output;
360 	*qop_state = GSS_C_QOP_DEFAULT;
361 
362 	if (conf_state)
363 		*conf_state = 1;
364 
365 	dprintf("Leaving gss_unseal\n");
366 	return (GSS_S_COMPLETE);
367 }
368 
369 /* EXPORT DELETE END */
370 
371 /*ARGSUSED*/
372 OM_uint32
373 	dummy_gss_import_sec_context(ct, minor_status, interprocess_token,
374 					context_handle)
375 void *ct;
376 OM_uint32 *minor_status;
377 gss_buffer_t interprocess_token;
378 gss_ctx_id_t *context_handle;
379 {
380 	unsigned char *ptr;
381 	int bodysize;
382 	int err;
383 
384 	/* Assume that we got ctx from the interprocess token. */
385 	dummy_gss_ctx_id_t ctx;
386 
387 	dprintf("Entering import_sec_context\n");
388 	ptr = (unsigned char *) interprocess_token->value;
389 	if (err = g_verify_token_header((gss_OID)gss_mech_dummy, &bodysize,
390 					&ptr, 0,
391 					interprocess_token->length)) {
392 		*minor_status = err;
393 		return (GSS_S_DEFECTIVE_TOKEN);
394 	}
395 	ctx = (dummy_gss_ctx_id_t)MALLOC(sizeof (dummy_gss_ctx_id_rec));
396 	ctx->token_number = MAGIC_TOKEN_NUMBER;
397 	ctx->established = 1;
398 
399 	*context_handle = (gss_ctx_id_t)ctx;
400 
401 	dprintf("Leaving import_sec_context\n");
402 	return (GSS_S_COMPLETE);
403 }
404 
405 /*ARGSUSED*/
406 static OM_uint32
407 dummy_gss_delete_sec_context(ct, minor_status,
408 			context_handle, output_token,
409 			gssd_ctx_verifier)
410 void *ct;
411 OM_uint32 *minor_status;
412 gss_ctx_id_t *context_handle;
413 gss_buffer_t output_token;
414 OM_uint32 gssd_ctx_verifier;
415 {
416 	dummy_gss_ctx_id_t ctx;
417 
418 	dprintf("Entering delete_sec_context\n");
419 
420 	/* Make the length to 0, so the output token is not sent to peer */
421 	if (output_token) {
422 		output_token->length = 0;
423 		output_token->value = NULL;
424 	}
425 
426 	if (*context_handle == GSS_C_NO_CONTEXT) {
427 		*minor_status = 0;
428 		return (GSS_S_COMPLETE);
429 	}
430 
431 	ctx = (dummy_gss_ctx_id_rec *) *context_handle;
432 	ASSERT(ctx->established == 1);
433 	ASSERT(ctx->token_number == MAGIC_TOKEN_NUMBER);
434 
435 	FREE(ctx, sizeof (dummy_gss_ctx_id_rec));
436 	*context_handle = GSS_C_NO_CONTEXT;
437 
438 	dprintf("Leaving delete_sec_context\n");
439 	return (GSS_S_COMPLETE);
440 }
441 
442 static int
443 der_length_size(int length)
444 {
445 	if (length < (1<<7))
446 		return (1);
447 	else if (length < (1<<8))
448 		return (2);
449 	else if (length < (1<<16))
450 		return (3);
451 	else if (length < (1<<24))
452 		return (4);
453 	else
454 		return (5);
455 }
456 
457 static void
458 der_write_length(unsigned char ** buf, int length)
459 {
460 	if (length < (1<<7)) {
461 		*(*buf)++ = (unsigned char) length;
462 	} else {
463 		*(*buf)++ = (unsigned char) (der_length_size(length)+127);
464 		if (length >= (1<<24))
465 			*(*buf)++ = (unsigned char) (length>>24);
466 		if (length >= (1<<16))
467 			*(*buf)++ = (unsigned char) ((length>>16)&0xff);
468 		if (length >= (1<<8))
469 			*(*buf)++ = (unsigned char) ((length>>8)&0xff);
470 		*(*buf)++ = (unsigned char) (length&0xff);
471 	}
472 }
473 
474 static int
475 der_read_length(buf, bufsize)
476 unsigned char **buf;
477 int *bufsize;
478 {
479 	unsigned char sf;
480 	int ret;
481 
482 	if (*bufsize < 1)
483 		return (-1);
484 	sf = *(*buf)++;
485 	(*bufsize)--;
486 	if (sf & 0x80) {
487 		if ((sf &= 0x7f) > ((*bufsize)-1))
488 			return (-1);
489 		if (sf > DUMMY_SIZE_OF_INT)
490 			return (-1);
491 		ret = 0;
492 		for (; sf; sf--) {
493 			ret = (ret<<8) + (*(*buf)++);
494 			(*bufsize)--;
495 		}
496 	} else {
497 		ret = sf;
498 	}
499 
500 	return (ret);
501 }
502 
503 static int
504 g_token_size(mech, body_size)
505 	gss_OID mech;
506 	unsigned int body_size;
507 {
508 	/* set body_size to sequence contents size */
509 	body_size += 4 + (int)mech->length;	/* NEED overflow check */
510 	return (1 + der_length_size(body_size) + body_size);
511 }
512 
513 static void
514 g_make_token_header(mech, body_size, buf, tok_type)
515 	gss_OID mech;
516 	int body_size;
517 	unsigned char **buf;
518 	int tok_type;
519 {
520 	*(*buf)++ = 0x60;
521 	der_write_length(buf, 4 + mech->length + body_size);
522 	*(*buf)++ = 0x06;
523 	*(*buf)++ = (unsigned char) mech->length;
524 	TWRITE_STR(*buf, mech->elements, ((int)mech->length));
525 	*(*buf)++ = (unsigned char) ((tok_type>>8)&0xff);
526 	*(*buf)++ = (unsigned char) (tok_type&0xff);
527 }
528 
529 static int
530 g_verify_token_header(mech, body_size, buf_in, tok_type, toksize)
531 	gss_OID mech;
532 	int *body_size;
533 	unsigned char **buf_in;
534 	int tok_type;
535 	int toksize;
536 {
537 	unsigned char *buf = *buf_in;
538 	int seqsize;
539 	gss_OID_desc toid;
540 	int ret = 0;
541 
542 	if ((toksize -= 1) < 0)
543 		return (G_BAD_TOK_HEADER);
544 	if (*buf++ != 0x60)
545 		return (G_BAD_TOK_HEADER);
546 
547 	if ((seqsize = der_read_length(&buf, &toksize)) < 0)
548 		return (G_BAD_TOK_HEADER);
549 
550 	if (seqsize != toksize)
551 		return (G_BAD_TOK_HEADER);
552 
553 	if ((toksize -= 1) < 0)
554 		return (G_BAD_TOK_HEADER);
555 	if (*buf++ != 0x06)
556 		return (G_BAD_TOK_HEADER);
557 
558 	if ((toksize -= 1) < 0)
559 		return (G_BAD_TOK_HEADER);
560 	toid.length = *buf++;
561 
562 	if ((toksize -= toid.length) < 0)
563 		return (G_BAD_TOK_HEADER);
564 	toid.elements = buf;
565 	buf += toid.length;
566 
567 	if (! g_OID_equal(&toid, mech))
568 		ret = G_WRONG_MECH;
569 
570 	/*
571 	 * G_WRONG_MECH is not returned immediately because it's more important
572 	 * to return G_BAD_TOK_HEADER if the token header is in fact bad
573 	 */
574 
575 	if ((toksize -= 2) < 0)
576 		return (G_BAD_TOK_HEADER);
577 
578 	if ((*buf++ != ((tok_type>>8)&0xff)) ||
579 	    (*buf++ != (tok_type&0xff)))
580 		return (G_BAD_TOK_HEADER);
581 
582 	if (!ret) {
583 		*buf_in = buf;
584 		*body_size = toksize;
585 	}
586 
587 	return (ret);
588 }
589 
590 static gss_buffer_desc
591 make_dummy_token_msg(void *data, int dataLen)
592 {
593 	gss_buffer_desc buffer;
594 	int tlen;
595 	unsigned char *t;
596 	unsigned char *ptr;
597 
598 	if (data == NULL) {
599 		buffer.length = 0;
600 		buffer.value = NULL;
601 		return (buffer);
602 	}
603 
604 	tlen = g_token_size((gss_OID)gss_mech_dummy, dataLen);
605 	t = (unsigned char *) MALLOC(tlen);
606 	ptr = t;
607 
608 	g_make_token_header((gss_OID)gss_mech_dummy, dataLen, &ptr, 0);
609 	(void) memcpy(ptr, data, dataLen);
610 
611 	buffer.length = tlen;
612 	buffer.value = (void *) t;
613 	return (buffer);
614 }
615