xref: /illumos-gate/usr/src/uts/common/crypto/io/arcfour.c (revision 8a8d276f)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * RC4 provider for the Kernel Cryptographic Framework (KCF)
30  */
31 
32 #include <sys/types.h>
33 #include <sys/systm.h>
34 #include <sys/modctl.h>
35 #include <sys/cmn_err.h>
36 #include <sys/ddi.h>
37 #include <sys/crypto/common.h>
38 #include <sys/crypto/spi.h>
39 #include <sys/sysmacros.h>
40 #include <sys/strsun.h>
41 #include <arcfour.h>
42 
43 extern struct mod_ops mod_cryptoops;
44 
45 /*
46  * Module linkage information for the kernel.
47  */
48 static struct modlcrypto modlcrypto = {
49 	&mod_cryptoops,
50 	"RC4 Kernel SW Provider %I%"
51 };
52 
53 static struct modlinkage modlinkage = {
54 	MODREV_1,
55 	(void *)&modlcrypto,
56 	NULL
57 };
58 
59 /*
60  * CSPI information (entry points, provider info, etc.)
61  */
62 
63 #define	RC4_MECH_INFO_TYPE	0
64 /*
65  * Mechanism info structure passed to KCF during registration.
66  */
67 static crypto_mech_info_t rc4_mech_info_tab[] = {
68 	{SUN_CKM_RC4, RC4_MECH_INFO_TYPE,
69 	    CRYPTO_FG_ENCRYPT | CRYPTO_FG_ENCRYPT_ATOMIC |
70 	    CRYPTO_FG_DECRYPT | CRYPTO_FG_DECRYPT_ATOMIC,
71 	    ARCFOUR_MIN_KEY_BITS, ARCFOUR_MAX_KEY_BITS,
72 	    CRYPTO_KEYSIZE_UNIT_IN_BITS | CRYPTO_CAN_SHARE_OPSTATE}
73 };
74 
75 static void rc4_provider_status(crypto_provider_handle_t, uint_t *);
76 
77 static crypto_control_ops_t rc4_control_ops = {
78 	rc4_provider_status
79 };
80 
81 static int rc4_common_init(crypto_ctx_t *, crypto_mechanism_t *,
82     crypto_key_t *, crypto_spi_ctx_template_t, crypto_req_handle_t);
83 
84 static int rc4_crypt_update(crypto_ctx_t *, crypto_data_t *, crypto_data_t *,
85     crypto_req_handle_t);
86 
87 static int rc4_crypt_final(crypto_ctx_t *, crypto_data_t *,
88     crypto_req_handle_t);
89 
90 static int rc4_crypt(crypto_ctx_t *, crypto_data_t *, crypto_data_t *,
91     crypto_req_handle_t);
92 
93 static int rc4_crypt_atomic(crypto_provider_handle_t, crypto_session_id_t,
94     crypto_mechanism_t *, crypto_key_t *, crypto_data_t *,
95     crypto_data_t *, crypto_spi_ctx_template_t, crypto_req_handle_t);
96 
97 
98 static crypto_cipher_ops_t rc4_cipher_ops = {
99 	rc4_common_init,
100 	rc4_crypt,
101 	rc4_crypt_update,
102 	rc4_crypt_final,
103 	rc4_crypt_atomic,
104 	rc4_common_init,
105 	rc4_crypt,
106 	rc4_crypt_update,
107 	rc4_crypt_final,
108 	rc4_crypt_atomic
109 };
110 
111 static int rc4_free_context(crypto_ctx_t *);
112 
113 static crypto_ctx_ops_t rc4_ctx_ops = {
114 	NULL,
115 	rc4_free_context
116 };
117 
118 static crypto_ops_t rc4_crypto_ops = {
119 	&rc4_control_ops,
120 	NULL,
121 	&rc4_cipher_ops,
122 	NULL,
123 	NULL,
124 	NULL,
125 	NULL,
126 	NULL,
127 	NULL,
128 	NULL,
129 	NULL,
130 	NULL,
131 	NULL,
132 	&rc4_ctx_ops
133 };
134 
135 static crypto_provider_info_t rc4_prov_info = {
136 	CRYPTO_SPI_VERSION_1,
137 	"RC4 Software Provider",
138 	CRYPTO_SW_PROVIDER,
139 	{&modlinkage},
140 	NULL,
141 	&rc4_crypto_ops,
142 	sizeof (rc4_mech_info_tab)/sizeof (crypto_mech_info_t),
143 	rc4_mech_info_tab
144 };
145 
146 static crypto_kcf_provider_handle_t rc4_prov_handle = NULL;
147 
148 static mblk_t *advance_position(mblk_t *, off_t, uchar_t **);
149 static int crypto_arcfour_crypt(ARCFour_key *, uchar_t *, crypto_data_t *,
150     int);
151 
152 int
153 _init(void)
154 {
155 	int ret;
156 
157 	/*
158 	 * Register with KCF. If the registration fails, log an error
159 	 * and uninstall the module.
160 	 */
161 	if ((ret = crypto_register_provider(&rc4_prov_info,
162 	    &rc4_prov_handle)) != CRYPTO_SUCCESS) {
163 		cmn_err(CE_WARN, "_init: crypto_register_provider(%s)"
164 		    "failed (0x%x)", "arcfour", ret);
165 		return (EACCES);
166 	}
167 
168 	if ((ret = mod_install(&modlinkage)) != 0) {
169 		int rv;
170 
171 		ASSERT(rc4_prov_handle != NULL);
172 		/* We should not return if the unregister returns busy. */
173 		while ((rv = crypto_unregister_provider(rc4_prov_handle))
174 		    == CRYPTO_BUSY) {
175 			cmn_err(CE_WARN, "_init: crypto_unregister_provider(%s)"
176 			    " failed (0x%x). Retrying.", "arcfour", rv);
177 			/* wait 10 seconds and try again. */
178 			delay(10 * drv_usectohz(1000000));
179 		}
180 	}
181 
182 	return (0);
183 }
184 
185 int
186 _fini(void)
187 {
188 	int ret;
189 
190 	/*
191 	 * Unregister from KCF if previous registration succeeded.
192 	 */
193 	if (rc4_prov_handle != NULL) {
194 		if ((ret = crypto_unregister_provider(rc4_prov_handle)) !=
195 		    CRYPTO_SUCCESS) {
196 			cmn_err(CE_WARN, "_fini: crypto_unregister_provider(%s)"
197 			    " failed (0x%x)", "arcfour", ret);
198 			return (EBUSY);
199 		}
200 		rc4_prov_handle = NULL;
201 	}
202 
203 	return (mod_remove(&modlinkage));
204 }
205 
206 int
207 _info(struct modinfo *modinfop)
208 {
209 	return (mod_info(&modlinkage, modinfop));
210 }
211 
212 
213 /*
214  * KCF software provider control entry points.
215  */
216 /* ARGSUSED */
217 static void
218 rc4_provider_status(crypto_provider_handle_t provider, uint_t *status)
219 {
220 	*status = CRYPTO_PROVIDER_READY;
221 }
222 
223 /* ARGSUSED */
224 static int
225 rc4_common_init(crypto_ctx_t *ctx, crypto_mechanism_t *mechanism,
226     crypto_key_t *key, crypto_spi_ctx_template_t template,
227     crypto_req_handle_t req)
228 {
229 
230 /* EXPORT DELETE START */
231 
232 	ARCFour_key *keystream;
233 
234 	if ((mechanism)->cm_type != RC4_MECH_INFO_TYPE)
235 		return (CRYPTO_MECHANISM_INVALID);
236 
237 	if (key->ck_format != CRYPTO_KEY_RAW)
238 		return (CRYPTO_KEY_TYPE_INCONSISTENT);
239 
240 	if (key->ck_length < ARCFOUR_MIN_KEY_BITS ||
241 	    key->ck_length > ARCFOUR_MAX_KEY_BITS) {
242 		return (CRYPTO_KEY_SIZE_RANGE);
243 	}
244 
245 	/*
246 	 * Allocate an RC4 key stream.
247 	 */
248 	if ((keystream = kmem_alloc(sizeof (ARCFour_key),
249 	    crypto_kmflag(req))) == NULL)
250 		return (CRYPTO_HOST_MEMORY);
251 
252 	arcfour_key_init(keystream, key->ck_data, key->ck_length >> 3);
253 
254 	ctx->cc_provider_private = keystream;
255 
256 /* EXPORT DELETE END */
257 
258 	return (CRYPTO_SUCCESS);
259 }
260 
261 static int
262 rc4_crypt(crypto_ctx_t *ctx, crypto_data_t *input, crypto_data_t *output,
263     crypto_req_handle_t req)
264 {
265 	int ret;
266 
267 	ret = rc4_crypt_update(ctx, input, output, req);
268 
269 	if (ret != CRYPTO_BUFFER_TOO_SMALL)
270 		(void) rc4_free_context(ctx);
271 
272 	return (ret);
273 }
274 
275 /* ARGSUSED */
276 static int
277 rc4_crypt_update(crypto_ctx_t *ctx, crypto_data_t *input, crypto_data_t *output,
278     crypto_req_handle_t req)
279 {
280 	int ret = CRYPTO_SUCCESS;
281 
282 /* EXPORT DELETE START */
283 
284 	ARCFour_key *key;
285 	off_t saveoffset;
286 
287 	ASSERT(ctx->cc_provider_private != NULL);
288 
289 	if ((ctx->cc_flags & CRYPTO_USE_OPSTATE) && ctx->cc_opstate != NULL)
290 		key = ctx->cc_opstate;
291 	else
292 		key = ctx->cc_provider_private;
293 
294 	/* Simple case: in-line encipherment */
295 
296 	if (output == NULL) {
297 		switch (input->cd_format) {
298 		case CRYPTO_DATA_RAW: {
299 			char *start, *end;
300 			start = input->cd_raw.iov_base + input->cd_offset;
301 
302 			end =  input->cd_raw.iov_base + input->cd_raw.iov_len;
303 
304 			if (start + input->cd_length > end)
305 				return (CRYPTO_DATA_INVALID);
306 
307 			arcfour_crypt(key, (uchar_t *)start, (uchar_t *)start,
308 			    input->cd_length);
309 			break;
310 		}
311 		case CRYPTO_DATA_MBLK: {
312 			uchar_t *start, *end;
313 			size_t len, left;
314 			mblk_t *mp = input->cd_mp, *mp1, *mp2;
315 
316 			ASSERT(mp != NULL);
317 
318 			mp1 = advance_position(mp, input->cd_offset, &start);
319 
320 			if (mp1 == NULL)
321 				return (CRYPTO_DATA_LEN_RANGE);
322 
323 			mp2 = advance_position(mp, input->cd_offset +
324 			    input->cd_length, &end);
325 
326 			if (mp2 == NULL)
327 				return (CRYPTO_DATA_LEN_RANGE);
328 
329 			left = input->cd_length;
330 			while (mp1 != NULL) {
331 				if (mp1->b_wptr - start > left) {
332 					len = left;
333 					arcfour_crypt(key, start, start, len);
334 					mp1 = NULL;
335 				} else {
336 					len = mp1->b_wptr - start;
337 					arcfour_crypt(key, start, start, len);
338 					mp1 = mp1->b_cont;
339 					start = mp1->b_rptr;
340 					left -= len;
341 				}
342 			}
343 			break;
344 		}
345 		case CRYPTO_DATA_UIO: {
346 			uio_t *uiop = input->cd_uio;
347 			off_t offset = input->cd_offset;
348 			size_t length = input->cd_length;
349 			uint_t vec_idx;
350 			size_t cur_len;
351 
352 			/*
353 			 * Jump to the first iovec containing data to be
354 			 * processed.
355 			 */
356 			for (vec_idx = 0; vec_idx < uiop->uio_iovcnt &&
357 			    offset >= uiop->uio_iov[vec_idx].iov_len;
358 			    offset -= uiop->uio_iov[vec_idx++].iov_len);
359 			if (vec_idx == uiop->uio_iovcnt) {
360 				return (CRYPTO_DATA_LEN_RANGE);
361 			}
362 
363 			/*
364 			 * Now process the iovecs.
365 			 */
366 			while (vec_idx < uiop->uio_iovcnt && length > 0) {
367 				uchar_t *start;
368 				iovec_t *iovp = &(uiop->uio_iov[vec_idx]);
369 
370 				cur_len = MIN(iovp->iov_len - offset, length);
371 
372 				start = (uchar_t *)(iovp->iov_base + offset);
373 				arcfour_crypt(key, start + offset,
374 				    start + offset, cur_len);
375 
376 				length -= cur_len;
377 				vec_idx++;
378 				offset = 0;
379 			}
380 
381 			if (vec_idx == uiop->uio_iovcnt && length > 0) {
382 
383 				return (CRYPTO_DATA_LEN_RANGE);
384 			}
385 			break;
386 		}
387 		}
388 		return (CRYPTO_SUCCESS);
389 	}
390 
391 	/*
392 	 * We need to just return the length needed to store the output.
393 	 * We should not destroy the context for the following case.
394 	 */
395 
396 	if (input->cd_length > output->cd_length) {
397 		output->cd_length = input->cd_length;
398 		return (CRYPTO_BUFFER_TOO_SMALL);
399 	}
400 
401 	saveoffset = output->cd_offset;
402 
403 	switch (input->cd_format) {
404 	case CRYPTO_DATA_RAW: {
405 		char *start, *end;
406 		start = input->cd_raw.iov_base + input->cd_offset;
407 
408 		end =  input->cd_raw.iov_base + input->cd_raw.iov_len;
409 
410 		if (start + input->cd_length > end)
411 			return (CRYPTO_DATA_LEN_RANGE);
412 
413 		ret = crypto_arcfour_crypt(key, (uchar_t *)start, output,
414 		    input->cd_length);
415 
416 		if (ret != CRYPTO_SUCCESS)
417 			return (ret);
418 		break;
419 	}
420 	case CRYPTO_DATA_MBLK: {
421 		uchar_t *start, *end;
422 		size_t len, left;
423 		mblk_t *mp = input->cd_mp, *mp1, *mp2;
424 
425 		ASSERT(mp != NULL);
426 
427 		mp1 = advance_position(mp, input->cd_offset, &start);
428 
429 		if (mp1 == NULL)
430 			return (CRYPTO_DATA_LEN_RANGE);
431 
432 		mp2 = advance_position(mp, input->cd_offset + input->cd_length,
433 		    &end);
434 
435 		if (mp2 == NULL)
436 			return (CRYPTO_DATA_LEN_RANGE);
437 
438 		left = input->cd_length;
439 		while (mp1 != NULL) {
440 			if (mp1->b_wptr - start > left) {
441 				len = left;
442 				ret = crypto_arcfour_crypt(key, start, output,
443 				    len);
444 				if (ret != CRYPTO_SUCCESS)
445 					return (ret);
446 				mp1 = NULL;
447 			} else {
448 				len = mp1->b_wptr - start;
449 				ret = crypto_arcfour_crypt(key, start, output,
450 				    len);
451 				if (ret != CRYPTO_SUCCESS)
452 					return (ret);
453 				mp1 = mp1->b_cont;
454 				start = mp1->b_rptr;
455 				left -= len;
456 				output->cd_offset += len;
457 			}
458 		}
459 		break;
460 	}
461 	case CRYPTO_DATA_UIO: {
462 		uio_t *uiop = input->cd_uio;
463 		off_t offset = input->cd_offset;
464 		size_t length = input->cd_length;
465 		uint_t vec_idx;
466 		size_t cur_len;
467 
468 		/*
469 		 * Jump to the first iovec containing data to be
470 		 * processed.
471 		 */
472 		for (vec_idx = 0; vec_idx < uiop->uio_iovcnt &&
473 		    offset >= uiop->uio_iov[vec_idx].iov_len;
474 		    offset -= uiop->uio_iov[vec_idx++].iov_len);
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 (mp1->b_wptr - start > left) {
611 					len = left;
612 					arcfour_crypt(key, in, start, len);
613 					mp1 = NULL;
614 				} else {
615 					len = 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 			if (vec_idx == uiop->uio_iovcnt) {
639 				return (CRYPTO_DATA_LEN_RANGE);
640 			}
641 
642 			/*
643 			 * Now process the iovecs.
644 			 */
645 			while (vec_idx < uiop->uio_iovcnt && len > 0) {
646 				uchar_t *start;
647 				iovec_t *iovp = &(uiop->uio_iov[vec_idx]);
648 				cur_len = MIN(iovp->iov_len - offset, len);
649 
650 				start = (uchar_t *)(iovp->iov_base + offset);
651 				arcfour_crypt(key, start + offset,
652 				    start + offset, cur_len);
653 
654 				len -= cur_len;
655 				vec_idx++;
656 				offset = 0;
657 			}
658 
659 			if (vec_idx == uiop->uio_iovcnt && len > 0) {
660 				return (CRYPTO_DATA_LEN_RANGE);
661 			}
662 			break;
663 		}
664 		default:
665 			return (CRYPTO_DATA_INVALID);
666 	}
667 	return (CRYPTO_SUCCESS);
668 }
669 
670 /*
671  * Advances 'offset' bytes from the beginning of the first block in 'mp',
672  * possibly jumping across b_cont boundary
673  * '*cpp' is set to the position of the byte we want, and the block where
674  * 'cpp' is returned.
675  */
676 static mblk_t *
677 advance_position(mblk_t *mp, off_t offset, uchar_t **cpp)
678 {
679 	mblk_t *mp1 = mp;
680 	size_t l;
681 	off_t o = offset;
682 
683 	while (mp1 != NULL) {
684 		l = MBLKL(mp1);
685 
686 		if (l <= o) {
687 			o -= l;
688 			mp1 = mp1->b_cont;
689 		} else {
690 			*cpp = (uchar_t *)(mp1->b_rptr + o);
691 			break;
692 		}
693 	}
694 	return (mp1);
695 }
696