xref: /illumos-gate/usr/src/uts/common/crypto/io/arcfour.c (revision 7a088f03b431bdffa96c3b2175964d4d38420caa)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * RC4 provider for the Kernel Cryptographic Framework (KCF)
28  */
29 
30 #include <sys/types.h>
31 #include <sys/systm.h>
32 #include <sys/modctl.h>
33 #include <sys/cmn_err.h>
34 #include <sys/ddi.h>
35 #include <sys/crypto/common.h>
36 #include <sys/crypto/spi.h>
37 #include <sys/sysmacros.h>
38 #include <sys/strsun.h>
39 #include <arcfour.h>
40 
41 extern struct mod_ops mod_cryptoops;
42 
43 /*
44  * Module linkage information for the kernel.
45  */
46 static struct modlcrypto modlcrypto = {
47 	&mod_cryptoops,
48 	"RC4 Kernel SW Provider"
49 };
50 
51 static struct modlinkage modlinkage = {
52 	MODREV_1,
53 	(void *)&modlcrypto,
54 	NULL
55 };
56 
57 /*
58  * CSPI information (entry points, provider info, etc.)
59  */
60 
61 #define	RC4_MECH_INFO_TYPE	0
62 /*
63  * Mechanism info structure passed to KCF during registration.
64  */
65 static crypto_mech_info_t rc4_mech_info_tab[] = {
66 	{SUN_CKM_RC4, RC4_MECH_INFO_TYPE,
67 	    CRYPTO_FG_ENCRYPT | CRYPTO_FG_ENCRYPT_ATOMIC |
68 	    CRYPTO_FG_DECRYPT | CRYPTO_FG_DECRYPT_ATOMIC,
69 	    ARCFOUR_MIN_KEY_BITS, ARCFOUR_MAX_KEY_BITS,
70 	    CRYPTO_KEYSIZE_UNIT_IN_BITS | CRYPTO_CAN_SHARE_OPSTATE}
71 };
72 
73 static void rc4_provider_status(crypto_provider_handle_t, uint_t *);
74 
75 static crypto_control_ops_t rc4_control_ops = {
76 	rc4_provider_status
77 };
78 
79 static int rc4_common_init(crypto_ctx_t *, crypto_mechanism_t *,
80     crypto_key_t *, crypto_spi_ctx_template_t, crypto_req_handle_t);
81 
82 static int rc4_crypt_update(crypto_ctx_t *, crypto_data_t *, crypto_data_t *,
83     crypto_req_handle_t);
84 
85 static int rc4_crypt_final(crypto_ctx_t *, crypto_data_t *,
86     crypto_req_handle_t);
87 
88 static int rc4_crypt(crypto_ctx_t *, crypto_data_t *, crypto_data_t *,
89     crypto_req_handle_t);
90 
91 static int rc4_crypt_atomic(crypto_provider_handle_t, crypto_session_id_t,
92     crypto_mechanism_t *, crypto_key_t *, crypto_data_t *,
93     crypto_data_t *, crypto_spi_ctx_template_t, crypto_req_handle_t);
94 
95 
96 static crypto_cipher_ops_t rc4_cipher_ops = {
97 	rc4_common_init,
98 	rc4_crypt,
99 	rc4_crypt_update,
100 	rc4_crypt_final,
101 	rc4_crypt_atomic,
102 	rc4_common_init,
103 	rc4_crypt,
104 	rc4_crypt_update,
105 	rc4_crypt_final,
106 	rc4_crypt_atomic
107 };
108 
109 static int rc4_free_context(crypto_ctx_t *);
110 
111 static crypto_ctx_ops_t rc4_ctx_ops = {
112 	NULL,
113 	rc4_free_context
114 };
115 
116 static crypto_ops_t rc4_crypto_ops = {
117 	&rc4_control_ops,
118 	NULL,
119 	&rc4_cipher_ops,
120 	NULL,
121 	NULL,
122 	NULL,
123 	NULL,
124 	NULL,
125 	NULL,
126 	NULL,
127 	NULL,
128 	NULL,
129 	NULL,
130 	&rc4_ctx_ops
131 };
132 
133 static crypto_provider_info_t rc4_prov_info = {
134 	CRYPTO_SPI_VERSION_1,
135 	"RC4 Software Provider",
136 	CRYPTO_SW_PROVIDER,
137 	{&modlinkage},
138 	NULL,
139 	&rc4_crypto_ops,
140 	sizeof (rc4_mech_info_tab)/sizeof (crypto_mech_info_t),
141 	rc4_mech_info_tab
142 };
143 
144 static crypto_kcf_provider_handle_t rc4_prov_handle = NULL;
145 
146 static mblk_t *advance_position(mblk_t *, off_t, uchar_t **);
147 static int crypto_arcfour_crypt(ARCFour_key *, uchar_t *, crypto_data_t *,
148     int);
149 
150 int
151 _init(void)
152 {
153 	int ret;
154 
155 	/*
156 	 * Register with KCF. If the registration fails, log an error
157 	 * and uninstall the module.
158 	 */
159 	if ((ret = crypto_register_provider(&rc4_prov_info,
160 	    &rc4_prov_handle)) != CRYPTO_SUCCESS) {
161 		cmn_err(CE_WARN, "_init: crypto_register_provider(%s)"
162 		    "failed (0x%x)", "arcfour", ret);
163 		return (EACCES);
164 	}
165 
166 	if ((ret = mod_install(&modlinkage)) != 0) {
167 		int rv;
168 
169 		ASSERT(rc4_prov_handle != NULL);
170 		/* We should not return if the unregister returns busy. */
171 		while ((rv = crypto_unregister_provider(rc4_prov_handle))
172 		    == CRYPTO_BUSY) {
173 			cmn_err(CE_WARN, "_init: crypto_unregister_provider(%s)"
174 			    " failed (0x%x). Retrying.", "arcfour", rv);
175 			/* wait 10 seconds and try again. */
176 			delay(10 * drv_usectohz(1000000));
177 		}
178 	}
179 
180 	return (0);
181 }
182 
183 int
184 _fini(void)
185 {
186 	int ret;
187 
188 	/*
189 	 * Unregister from KCF if previous registration succeeded.
190 	 */
191 	if (rc4_prov_handle != NULL) {
192 		if ((ret = crypto_unregister_provider(rc4_prov_handle)) !=
193 		    CRYPTO_SUCCESS) {
194 			cmn_err(CE_WARN, "_fini: crypto_unregister_provider(%s)"
195 			    " failed (0x%x)", "arcfour", ret);
196 			return (EBUSY);
197 		}
198 		rc4_prov_handle = NULL;
199 	}
200 
201 	return (mod_remove(&modlinkage));
202 }
203 
204 int
205 _info(struct modinfo *modinfop)
206 {
207 	return (mod_info(&modlinkage, modinfop));
208 }
209 
210 
211 /*
212  * KCF software provider control entry points.
213  */
214 /* ARGSUSED */
215 static void
216 rc4_provider_status(crypto_provider_handle_t provider, uint_t *status)
217 {
218 	*status = CRYPTO_PROVIDER_READY;
219 }
220 
221 /* ARGSUSED */
222 static int
223 rc4_common_init(crypto_ctx_t *ctx, crypto_mechanism_t *mechanism,
224     crypto_key_t *key, crypto_spi_ctx_template_t template,
225     crypto_req_handle_t req)
226 {
227 
228 /* EXPORT DELETE START */
229 
230 	ARCFour_key *keystream;
231 
232 	if ((mechanism)->cm_type != RC4_MECH_INFO_TYPE)
233 		return (CRYPTO_MECHANISM_INVALID);
234 
235 	if (key->ck_format != CRYPTO_KEY_RAW)
236 		return (CRYPTO_KEY_TYPE_INCONSISTENT);
237 
238 	if (key->ck_length < ARCFOUR_MIN_KEY_BITS ||
239 	    key->ck_length > ARCFOUR_MAX_KEY_BITS) {
240 		return (CRYPTO_KEY_SIZE_RANGE);
241 	}
242 
243 	/*
244 	 * Allocate an RC4 key stream.
245 	 */
246 	if ((keystream = kmem_alloc(sizeof (ARCFour_key),
247 	    crypto_kmflag(req))) == NULL)
248 		return (CRYPTO_HOST_MEMORY);
249 
250 	arcfour_key_init(keystream, key->ck_data, key->ck_length >> 3);
251 
252 	ctx->cc_provider_private = keystream;
253 
254 /* EXPORT DELETE END */
255 
256 	return (CRYPTO_SUCCESS);
257 }
258 
259 static int
260 rc4_crypt(crypto_ctx_t *ctx, crypto_data_t *input, crypto_data_t *output,
261     crypto_req_handle_t req)
262 {
263 	int ret;
264 
265 	ret = rc4_crypt_update(ctx, input, output, req);
266 
267 	if (ret != CRYPTO_BUFFER_TOO_SMALL)
268 		(void) rc4_free_context(ctx);
269 
270 	return (ret);
271 }
272 
273 /* ARGSUSED */
274 static int
275 rc4_crypt_update(crypto_ctx_t *ctx, crypto_data_t *input, crypto_data_t *output,
276     crypto_req_handle_t req)
277 {
278 	int ret = CRYPTO_SUCCESS;
279 
280 /* EXPORT DELETE START */
281 
282 	ARCFour_key *key;
283 	off_t saveoffset;
284 
285 	ASSERT(ctx->cc_provider_private != NULL);
286 
287 	if ((ctx->cc_flags & CRYPTO_USE_OPSTATE) && ctx->cc_opstate != NULL)
288 		key = ctx->cc_opstate;
289 	else
290 		key = ctx->cc_provider_private;
291 
292 	/* Simple case: in-line encipherment */
293 
294 	if (output == NULL) {
295 		switch (input->cd_format) {
296 		case CRYPTO_DATA_RAW: {
297 			char *start, *end;
298 			start = input->cd_raw.iov_base + input->cd_offset;
299 
300 			end =  input->cd_raw.iov_base + input->cd_raw.iov_len;
301 
302 			if (start + input->cd_length > end)
303 				return (CRYPTO_DATA_INVALID);
304 
305 			arcfour_crypt(key, (uchar_t *)start, (uchar_t *)start,
306 			    input->cd_length);
307 			break;
308 		}
309 		case CRYPTO_DATA_MBLK: {
310 			uchar_t *start, *end;
311 			size_t len, left;
312 			mblk_t *mp = input->cd_mp, *mp1, *mp2;
313 
314 			ASSERT(mp != NULL);
315 
316 			mp1 = advance_position(mp, input->cd_offset, &start);
317 
318 			if (mp1 == NULL)
319 				return (CRYPTO_DATA_LEN_RANGE);
320 
321 			mp2 = advance_position(mp, input->cd_offset +
322 			    input->cd_length, &end);
323 
324 			if (mp2 == NULL)
325 				return (CRYPTO_DATA_LEN_RANGE);
326 
327 			left = input->cd_length;
328 			while (mp1 != NULL) {
329 				if (_PTRDIFF(mp1->b_wptr, start) > left) {
330 					len = left;
331 					arcfour_crypt(key, start, start, len);
332 					mp1 = NULL;
333 				} else {
334 					len = _PTRDIFF(mp1->b_wptr, start);
335 					arcfour_crypt(key, start, start, len);
336 					mp1 = mp1->b_cont;
337 					start = mp1->b_rptr;
338 					left -= len;
339 				}
340 			}
341 			break;
342 		}
343 		case CRYPTO_DATA_UIO: {
344 			uio_t *uiop = input->cd_uio;
345 			off_t offset = input->cd_offset;
346 			size_t length = input->cd_length;
347 			uint_t vec_idx;
348 			size_t cur_len;
349 
350 			/*
351 			 * Jump to the first iovec containing data to be
352 			 * processed.
353 			 */
354 			for (vec_idx = 0; vec_idx < uiop->uio_iovcnt &&
355 			    offset >= uiop->uio_iov[vec_idx].iov_len;
356 			    offset -= uiop->uio_iov[vec_idx++].iov_len)
357 				;
358 			if (vec_idx == uiop->uio_iovcnt) {
359 				return (CRYPTO_DATA_LEN_RANGE);
360 			}
361 
362 			/*
363 			 * Now process the iovecs.
364 			 */
365 			while (vec_idx < uiop->uio_iovcnt && length > 0) {
366 				uchar_t *start;
367 				iovec_t *iovp = &(uiop->uio_iov[vec_idx]);
368 
369 				cur_len = MIN(iovp->iov_len - offset, length);
370 
371 				start = (uchar_t *)(iovp->iov_base + offset);
372 				arcfour_crypt(key, start + offset,
373 				    start + offset, cur_len);
374 
375 				length -= cur_len;
376 				vec_idx++;
377 				offset = 0;
378 			}
379 
380 			if (vec_idx == uiop->uio_iovcnt && length > 0) {
381 
382 				return (CRYPTO_DATA_LEN_RANGE);
383 			}
384 			break;
385 		}
386 		}
387 		return (CRYPTO_SUCCESS);
388 	}
389 
390 	/*
391 	 * We need to just return the length needed to store the output.
392 	 * We should not destroy the context for the following case.
393 	 */
394 
395 	if (input->cd_length > output->cd_length) {
396 		output->cd_length = input->cd_length;
397 		return (CRYPTO_BUFFER_TOO_SMALL);
398 	}
399 
400 	saveoffset = output->cd_offset;
401 
402 	switch (input->cd_format) {
403 	case CRYPTO_DATA_RAW: {
404 		char *start, *end;
405 		start = input->cd_raw.iov_base + input->cd_offset;
406 
407 		end =  input->cd_raw.iov_base + input->cd_raw.iov_len;
408 
409 		if (start + input->cd_length > end)
410 			return (CRYPTO_DATA_LEN_RANGE);
411 
412 		ret = crypto_arcfour_crypt(key, (uchar_t *)start, output,
413 		    input->cd_length);
414 
415 		if (ret != CRYPTO_SUCCESS)
416 			return (ret);
417 		break;
418 	}
419 	case CRYPTO_DATA_MBLK: {
420 		uchar_t *start, *end;
421 		size_t len, left;
422 		mblk_t *mp = input->cd_mp, *mp1, *mp2;
423 
424 		ASSERT(mp != NULL);
425 
426 		mp1 = advance_position(mp, input->cd_offset, &start);
427 
428 		if (mp1 == NULL)
429 			return (CRYPTO_DATA_LEN_RANGE);
430 
431 		mp2 = advance_position(mp, input->cd_offset + input->cd_length,
432 		    &end);
433 
434 		if (mp2 == NULL)
435 			return (CRYPTO_DATA_LEN_RANGE);
436 
437 		left = input->cd_length;
438 		while (mp1 != NULL) {
439 			if (_PTRDIFF(mp1->b_wptr, start) > left) {
440 				len = left;
441 				ret = crypto_arcfour_crypt(key, start, output,
442 				    len);
443 				if (ret != CRYPTO_SUCCESS)
444 					return (ret);
445 				mp1 = NULL;
446 			} else {
447 				len = _PTRDIFF(mp1->b_wptr, start);
448 				ret = crypto_arcfour_crypt(key, start, output,
449 				    len);
450 				if (ret != CRYPTO_SUCCESS)
451 					return (ret);
452 				mp1 = mp1->b_cont;
453 				start = mp1->b_rptr;
454 				left -= len;
455 				output->cd_offset += len;
456 			}
457 		}
458 		break;
459 	}
460 	case CRYPTO_DATA_UIO: {
461 		uio_t *uiop = input->cd_uio;
462 		off_t offset = input->cd_offset;
463 		size_t length = input->cd_length;
464 		uint_t vec_idx;
465 		size_t cur_len;
466 
467 		/*
468 		 * Jump to the first iovec containing data to be
469 		 * processed.
470 		 */
471 		for (vec_idx = 0; vec_idx < uiop->uio_iovcnt &&
472 		    offset >= uiop->uio_iov[vec_idx].iov_len;
473 		    offset -= uiop->uio_iov[vec_idx++].iov_len)
474 			;
475 		if (vec_idx == uiop->uio_iovcnt) {
476 			return (CRYPTO_DATA_LEN_RANGE);
477 		}
478 
479 		/*
480 		 * Now process the iovecs.
481 		 */
482 		while (vec_idx < uiop->uio_iovcnt && length > 0) {
483 			uchar_t *start;
484 			iovec_t *iovp = &(uiop->uio_iov[vec_idx]);
485 			cur_len = MIN(iovp->iov_len - offset, length);
486 
487 			start = (uchar_t *)(iovp->iov_base + offset);
488 			ret = crypto_arcfour_crypt(key, start + offset,
489 			    output, cur_len);
490 			if (ret != CRYPTO_SUCCESS)
491 				return (ret);
492 
493 			length -= cur_len;
494 			vec_idx++;
495 			offset = 0;
496 			output->cd_offset += cur_len;
497 		}
498 
499 		if (vec_idx == uiop->uio_iovcnt && length > 0) {
500 
501 			return (CRYPTO_DATA_LEN_RANGE);
502 		}
503 	}
504 	}
505 
506 	output->cd_offset = saveoffset;
507 	output->cd_length = input->cd_length;
508 
509 /* EXPORT DELETE END */
510 
511 	return (ret);
512 }
513 
514 /* ARGSUSED */
515 static int rc4_crypt_final(crypto_ctx_t *ctx, crypto_data_t *data,
516     crypto_req_handle_t req)
517 {
518 	/* No final part for streams ciphers. Just free the context */
519 	if (data != NULL)
520 		data->cd_length = 0;
521 
522 	return (rc4_free_context(ctx));
523 }
524 
525 /* ARGSUSED */
526 static int
527 rc4_crypt_atomic(crypto_provider_handle_t handle, crypto_session_id_t session,
528     crypto_mechanism_t *mechanism, crypto_key_t *key, crypto_data_t *input,
529     crypto_data_t *output, crypto_spi_ctx_template_t template,
530     crypto_req_handle_t req)
531 {
532 	crypto_ctx_t ctx;
533 	int ret;
534 
535 	bzero(&ctx, sizeof (crypto_ctx_t));
536 	ret = rc4_common_init(&ctx, mechanism, key, template, req);
537 
538 	if (ret != CRYPTO_SUCCESS)
539 		return (ret);
540 
541 	ret = rc4_crypt_update(&ctx, input, output, req);
542 
543 	(void) rc4_free_context(&ctx);
544 
545 	return (ret);
546 }
547 
548 /* ARGSUSED */
549 static int
550 rc4_free_context(crypto_ctx_t *ctx)
551 {
552 
553 /* EXPORT DELETE START */
554 
555 	ARCFour_key *keystream = ctx->cc_provider_private;
556 
557 	if (keystream != NULL) {
558 		bzero(keystream, sizeof (ARCFour_key));
559 		kmem_free(keystream, sizeof (ARCFour_key));
560 		ctx->cc_provider_private = NULL;
561 	}
562 
563 /* EXPORT DELETE END */
564 
565 	return (CRYPTO_SUCCESS);
566 }
567 
568 /* Encrypts a contiguous input 'in' into the 'out' crypto_data_t */
569 
570 static int
571 crypto_arcfour_crypt(ARCFour_key *key, uchar_t *in, crypto_data_t *out,
572     int length)
573 {
574 	switch (out->cd_format) {
575 		case CRYPTO_DATA_RAW: {
576 			uchar_t *start, *end;
577 			start = (uchar_t *)(out->cd_raw.iov_base +
578 			    out->cd_offset);
579 
580 			end = (uchar_t *)(out->cd_raw.iov_base +
581 			    out->cd_raw.iov_len);
582 
583 			if (start + out->cd_length > end)
584 				return (CRYPTO_DATA_LEN_RANGE);
585 
586 			arcfour_crypt(key, in, start, length);
587 
588 			return (CRYPTO_SUCCESS);
589 		}
590 		case CRYPTO_DATA_MBLK: {
591 			uchar_t *start, *end;
592 			size_t len, left;
593 			mblk_t *mp = out->cd_mp, *mp1, *mp2;
594 
595 			ASSERT(mp != NULL);
596 
597 			mp1 = advance_position(mp, out->cd_offset, &start);
598 
599 			if (mp1 == NULL)
600 				return (CRYPTO_DATA_LEN_RANGE);
601 
602 			mp2 = advance_position(mp, out->cd_offset +
603 			    out->cd_length, &end);
604 
605 			if (mp2 == NULL)
606 				return (CRYPTO_DATA_LEN_RANGE);
607 
608 			left = length;
609 			while (mp1 != NULL) {
610 				if (_PTRDIFF(mp1->b_wptr, start) > left) {
611 					len = left;
612 					arcfour_crypt(key, in, start, len);
613 					mp1 = NULL;
614 				} else {
615 					len = _PTRDIFF(mp1->b_wptr, start);
616 					arcfour_crypt(key, in, start, len);
617 					mp1 = mp1->b_cont;
618 					start = mp1->b_rptr;
619 					left -= len;
620 				}
621 			}
622 			break;
623 		}
624 		case CRYPTO_DATA_UIO: {
625 			uio_t *uiop = out->cd_uio;
626 			off_t offset = out->cd_offset;
627 			size_t len = length;
628 			uint_t vec_idx;
629 			size_t cur_len;
630 
631 			/*
632 			 * Jump to the first iovec containing data to be
633 			 * processed.
634 			 */
635 			for (vec_idx = 0; vec_idx < uiop->uio_iovcnt &&
636 			    offset >= uiop->uio_iov[vec_idx].iov_len;
637 			    offset -= uiop->uio_iov[vec_idx++].iov_len)
638 				;
639 			if (vec_idx == uiop->uio_iovcnt) {
640 				return (CRYPTO_DATA_LEN_RANGE);
641 			}
642 
643 			/*
644 			 * Now process the iovecs.
645 			 */
646 			while (vec_idx < uiop->uio_iovcnt && len > 0) {
647 				uchar_t *start;
648 				iovec_t *iovp = &(uiop->uio_iov[vec_idx]);
649 				cur_len = MIN(iovp->iov_len - offset, len);
650 
651 				start = (uchar_t *)(iovp->iov_base + offset);
652 				arcfour_crypt(key, start + offset,
653 				    start + offset, cur_len);
654 
655 				len -= cur_len;
656 				vec_idx++;
657 				offset = 0;
658 			}
659 
660 			if (vec_idx == uiop->uio_iovcnt && len > 0) {
661 				return (CRYPTO_DATA_LEN_RANGE);
662 			}
663 			break;
664 		}
665 		default:
666 			return (CRYPTO_DATA_INVALID);
667 	}
668 	return (CRYPTO_SUCCESS);
669 }
670 
671 /*
672  * Advances 'offset' bytes from the beginning of the first block in 'mp',
673  * possibly jumping across b_cont boundary
674  * '*cpp' is set to the position of the byte we want, and the block where
675  * 'cpp' is returned.
676  */
677 static mblk_t *
678 advance_position(mblk_t *mp, off_t offset, uchar_t **cpp)
679 {
680 	mblk_t *mp1 = mp;
681 	size_t l;
682 	off_t o = offset;
683 
684 	while (mp1 != NULL) {
685 		l = MBLKL(mp1);
686 
687 		if (l <= o) {
688 			o -= l;
689 			mp1 = mp1->b_cont;
690 		} else {
691 			*cpp = (uchar_t *)(mp1->b_rptr + o);
692 			break;
693 		}
694 	}
695 	return (mp1);
696 }
697