xref: /linux/drivers/nvme/host/auth.c (revision 182fff3a2aafe4e7f3717a0be9df2fe2ed1a77de)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2020 Hannes Reinecke, SUSE Linux
4  */
5 
6 #include <linux/crc32.h>
7 #include <linux/base64.h>
8 #include <linux/prandom.h>
9 #include <linux/unaligned.h>
10 #include <crypto/hash.h>
11 #include <crypto/dh.h>
12 #include "nvme.h"
13 #include "fabrics.h"
14 #include <linux/nvme-auth.h>
15 
16 #define CHAP_BUF_SIZE 4096
17 static struct kmem_cache *nvme_chap_buf_cache;
18 static mempool_t *nvme_chap_buf_pool;
19 
20 struct nvme_dhchap_queue_context {
21 	struct list_head entry;
22 	struct work_struct auth_work;
23 	struct nvme_ctrl *ctrl;
24 	struct crypto_shash *shash_tfm;
25 	struct crypto_kpp *dh_tfm;
26 	struct nvme_dhchap_key *transformed_key;
27 	void *buf;
28 	int qid;
29 	int error;
30 	u32 s1;
31 	u32 s2;
32 	bool bi_directional;
33 	u16 transaction;
34 	u8 status;
35 	u8 dhgroup_id;
36 	u8 hash_id;
37 	size_t hash_len;
38 	u8 c1[64];
39 	u8 c2[64];
40 	u8 response[64];
41 	u8 *ctrl_key;
42 	u8 *host_key;
43 	u8 *sess_key;
44 	int ctrl_key_len;
45 	int host_key_len;
46 	int sess_key_len;
47 };
48 
49 static struct workqueue_struct *nvme_auth_wq;
50 
51 static inline int ctrl_max_dhchaps(struct nvme_ctrl *ctrl)
52 {
53 	return ctrl->opts->nr_io_queues + ctrl->opts->nr_write_queues +
54 			ctrl->opts->nr_poll_queues + 1;
55 }
56 
57 static int nvme_auth_submit(struct nvme_ctrl *ctrl, int qid,
58 			    void *data, size_t data_len, bool auth_send)
59 {
60 	struct nvme_command cmd = {};
61 	nvme_submit_flags_t flags = NVME_SUBMIT_RETRY;
62 	struct request_queue *q = ctrl->fabrics_q;
63 	int ret;
64 
65 	if (qid != 0) {
66 		flags |= NVME_SUBMIT_NOWAIT | NVME_SUBMIT_RESERVED;
67 		q = ctrl->connect_q;
68 	}
69 
70 	cmd.auth_common.opcode = nvme_fabrics_command;
71 	cmd.auth_common.secp = NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER;
72 	cmd.auth_common.spsp0 = 0x01;
73 	cmd.auth_common.spsp1 = 0x01;
74 	if (auth_send) {
75 		cmd.auth_send.fctype = nvme_fabrics_type_auth_send;
76 		cmd.auth_send.tl = cpu_to_le32(data_len);
77 	} else {
78 		cmd.auth_receive.fctype = nvme_fabrics_type_auth_receive;
79 		cmd.auth_receive.al = cpu_to_le32(data_len);
80 	}
81 
82 	ret = __nvme_submit_sync_cmd(q, &cmd, NULL, data, data_len,
83 				     qid == 0 ? NVME_QID_ANY : qid, flags);
84 	if (ret > 0)
85 		dev_warn(ctrl->device,
86 			"qid %d auth_send failed with status %d\n", qid, ret);
87 	else if (ret < 0)
88 		dev_err(ctrl->device,
89 			"qid %d auth_send failed with error %d\n", qid, ret);
90 	return ret;
91 }
92 
93 static int nvme_auth_receive_validate(struct nvme_ctrl *ctrl, int qid,
94 		struct nvmf_auth_dhchap_failure_data *data,
95 		u16 transaction, u8 expected_msg)
96 {
97 	dev_dbg(ctrl->device, "%s: qid %d auth_type %d auth_id %x\n",
98 		__func__, qid, data->auth_type, data->auth_id);
99 
100 	if (data->auth_type == NVME_AUTH_COMMON_MESSAGES &&
101 	    data->auth_id == NVME_AUTH_DHCHAP_MESSAGE_FAILURE1) {
102 		return data->rescode_exp;
103 	}
104 	if (data->auth_type != NVME_AUTH_DHCHAP_MESSAGES ||
105 	    data->auth_id != expected_msg) {
106 		dev_warn(ctrl->device,
107 			 "qid %d invalid message %02x/%02x\n",
108 			 qid, data->auth_type, data->auth_id);
109 		return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_MESSAGE;
110 	}
111 	if (le16_to_cpu(data->t_id) != transaction) {
112 		dev_warn(ctrl->device,
113 			 "qid %d invalid transaction ID %d\n",
114 			 qid, le16_to_cpu(data->t_id));
115 		return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_MESSAGE;
116 	}
117 	return 0;
118 }
119 
120 static int nvme_auth_set_dhchap_negotiate_data(struct nvme_ctrl *ctrl,
121 		struct nvme_dhchap_queue_context *chap)
122 {
123 	struct nvmf_auth_dhchap_negotiate_data *data = chap->buf;
124 	size_t size = sizeof(*data) + sizeof(union nvmf_auth_protocol);
125 
126 	if (size > CHAP_BUF_SIZE) {
127 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
128 		return -EINVAL;
129 	}
130 	memset((u8 *)chap->buf, 0, size);
131 	data->auth_type = NVME_AUTH_COMMON_MESSAGES;
132 	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_NEGOTIATE;
133 	data->t_id = cpu_to_le16(chap->transaction);
134 	data->sc_c = 0; /* No secure channel concatenation */
135 	data->napd = 1;
136 	data->auth_protocol[0].dhchap.authid = NVME_AUTH_DHCHAP_AUTH_ID;
137 	data->auth_protocol[0].dhchap.halen = 3;
138 	data->auth_protocol[0].dhchap.dhlen = 6;
139 	data->auth_protocol[0].dhchap.idlist[0] = NVME_AUTH_HASH_SHA256;
140 	data->auth_protocol[0].dhchap.idlist[1] = NVME_AUTH_HASH_SHA384;
141 	data->auth_protocol[0].dhchap.idlist[2] = NVME_AUTH_HASH_SHA512;
142 	data->auth_protocol[0].dhchap.idlist[30] = NVME_AUTH_DHGROUP_NULL;
143 	data->auth_protocol[0].dhchap.idlist[31] = NVME_AUTH_DHGROUP_2048;
144 	data->auth_protocol[0].dhchap.idlist[32] = NVME_AUTH_DHGROUP_3072;
145 	data->auth_protocol[0].dhchap.idlist[33] = NVME_AUTH_DHGROUP_4096;
146 	data->auth_protocol[0].dhchap.idlist[34] = NVME_AUTH_DHGROUP_6144;
147 	data->auth_protocol[0].dhchap.idlist[35] = NVME_AUTH_DHGROUP_8192;
148 
149 	return size;
150 }
151 
152 static int nvme_auth_process_dhchap_challenge(struct nvme_ctrl *ctrl,
153 		struct nvme_dhchap_queue_context *chap)
154 {
155 	struct nvmf_auth_dhchap_challenge_data *data = chap->buf;
156 	u16 dhvlen = le16_to_cpu(data->dhvlen);
157 	size_t size = sizeof(*data) + data->hl + dhvlen;
158 	const char *gid_name = nvme_auth_dhgroup_name(data->dhgid);
159 	const char *hmac_name, *kpp_name;
160 
161 	if (size > CHAP_BUF_SIZE) {
162 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
163 		return -EINVAL;
164 	}
165 
166 	hmac_name = nvme_auth_hmac_name(data->hashid);
167 	if (!hmac_name) {
168 		dev_warn(ctrl->device,
169 			 "qid %d: invalid HASH ID %d\n",
170 			 chap->qid, data->hashid);
171 		chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
172 		return -EPROTO;
173 	}
174 
175 	if (chap->hash_id == data->hashid && chap->shash_tfm &&
176 	    !strcmp(crypto_shash_alg_name(chap->shash_tfm), hmac_name) &&
177 	    crypto_shash_digestsize(chap->shash_tfm) == data->hl) {
178 		dev_dbg(ctrl->device,
179 			"qid %d: reuse existing hash %s\n",
180 			chap->qid, hmac_name);
181 		goto select_kpp;
182 	}
183 
184 	/* Reset if hash cannot be reused */
185 	if (chap->shash_tfm) {
186 		crypto_free_shash(chap->shash_tfm);
187 		chap->hash_id = 0;
188 		chap->hash_len = 0;
189 	}
190 	chap->shash_tfm = crypto_alloc_shash(hmac_name, 0,
191 					     CRYPTO_ALG_ALLOCATES_MEMORY);
192 	if (IS_ERR(chap->shash_tfm)) {
193 		dev_warn(ctrl->device,
194 			 "qid %d: failed to allocate hash %s, error %ld\n",
195 			 chap->qid, hmac_name, PTR_ERR(chap->shash_tfm));
196 		chap->shash_tfm = NULL;
197 		chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
198 		return -ENOMEM;
199 	}
200 
201 	if (crypto_shash_digestsize(chap->shash_tfm) != data->hl) {
202 		dev_warn(ctrl->device,
203 			 "qid %d: invalid hash length %d\n",
204 			 chap->qid, data->hl);
205 		crypto_free_shash(chap->shash_tfm);
206 		chap->shash_tfm = NULL;
207 		chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
208 		return -EPROTO;
209 	}
210 
211 	chap->hash_id = data->hashid;
212 	chap->hash_len = data->hl;
213 	dev_dbg(ctrl->device, "qid %d: selected hash %s\n",
214 		chap->qid, hmac_name);
215 
216 select_kpp:
217 	kpp_name = nvme_auth_dhgroup_kpp(data->dhgid);
218 	if (!kpp_name) {
219 		dev_warn(ctrl->device,
220 			 "qid %d: invalid DH group id %d\n",
221 			 chap->qid, data->dhgid);
222 		chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
223 		/* Leave previous dh_tfm intact */
224 		return -EPROTO;
225 	}
226 
227 	if (chap->dhgroup_id == data->dhgid &&
228 	    (data->dhgid == NVME_AUTH_DHGROUP_NULL || chap->dh_tfm)) {
229 		dev_dbg(ctrl->device,
230 			"qid %d: reuse existing DH group %s\n",
231 			chap->qid, gid_name);
232 		goto skip_kpp;
233 	}
234 
235 	/* Reset dh_tfm if it can't be reused */
236 	if (chap->dh_tfm) {
237 		crypto_free_kpp(chap->dh_tfm);
238 		chap->dh_tfm = NULL;
239 	}
240 
241 	if (data->dhgid != NVME_AUTH_DHGROUP_NULL) {
242 		if (dhvlen == 0) {
243 			dev_warn(ctrl->device,
244 				 "qid %d: empty DH value\n",
245 				 chap->qid);
246 			chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
247 			return -EPROTO;
248 		}
249 
250 		chap->dh_tfm = crypto_alloc_kpp(kpp_name, 0, 0);
251 		if (IS_ERR(chap->dh_tfm)) {
252 			int ret = PTR_ERR(chap->dh_tfm);
253 
254 			dev_warn(ctrl->device,
255 				 "qid %d: error %d initializing DH group %s\n",
256 				 chap->qid, ret, gid_name);
257 			chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
258 			chap->dh_tfm = NULL;
259 			return ret;
260 		}
261 		dev_dbg(ctrl->device, "qid %d: selected DH group %s\n",
262 			chap->qid, gid_name);
263 	} else if (dhvlen != 0) {
264 		dev_warn(ctrl->device,
265 			 "qid %d: invalid DH value for NULL DH\n",
266 			 chap->qid);
267 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
268 		return -EPROTO;
269 	}
270 	chap->dhgroup_id = data->dhgid;
271 
272 skip_kpp:
273 	chap->s1 = le32_to_cpu(data->seqnum);
274 	memcpy(chap->c1, data->cval, chap->hash_len);
275 	if (dhvlen) {
276 		chap->ctrl_key = kmalloc(dhvlen, GFP_KERNEL);
277 		if (!chap->ctrl_key) {
278 			chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
279 			return -ENOMEM;
280 		}
281 		chap->ctrl_key_len = dhvlen;
282 		memcpy(chap->ctrl_key, data->cval + chap->hash_len,
283 		       dhvlen);
284 		dev_dbg(ctrl->device, "ctrl public key %*ph\n",
285 			 (int)chap->ctrl_key_len, chap->ctrl_key);
286 	}
287 
288 	return 0;
289 }
290 
291 static int nvme_auth_set_dhchap_reply_data(struct nvme_ctrl *ctrl,
292 		struct nvme_dhchap_queue_context *chap)
293 {
294 	struct nvmf_auth_dhchap_reply_data *data = chap->buf;
295 	size_t size = sizeof(*data);
296 
297 	size += 2 * chap->hash_len;
298 
299 	if (chap->host_key_len)
300 		size += chap->host_key_len;
301 
302 	if (size > CHAP_BUF_SIZE) {
303 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
304 		return -EINVAL;
305 	}
306 
307 	memset(chap->buf, 0, size);
308 	data->auth_type = NVME_AUTH_DHCHAP_MESSAGES;
309 	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_REPLY;
310 	data->t_id = cpu_to_le16(chap->transaction);
311 	data->hl = chap->hash_len;
312 	data->dhvlen = cpu_to_le16(chap->host_key_len);
313 	memcpy(data->rval, chap->response, chap->hash_len);
314 	if (ctrl->ctrl_key) {
315 		chap->bi_directional = true;
316 		get_random_bytes(chap->c2, chap->hash_len);
317 		data->cvalid = 1;
318 		memcpy(data->rval + chap->hash_len, chap->c2,
319 		       chap->hash_len);
320 		dev_dbg(ctrl->device, "%s: qid %d ctrl challenge %*ph\n",
321 			__func__, chap->qid, (int)chap->hash_len, chap->c2);
322 	} else {
323 		memset(chap->c2, 0, chap->hash_len);
324 	}
325 	chap->s2 = nvme_auth_get_seqnum();
326 	data->seqnum = cpu_to_le32(chap->s2);
327 	if (chap->host_key_len) {
328 		dev_dbg(ctrl->device, "%s: qid %d host public key %*ph\n",
329 			__func__, chap->qid,
330 			chap->host_key_len, chap->host_key);
331 		memcpy(data->rval + 2 * chap->hash_len, chap->host_key,
332 		       chap->host_key_len);
333 	}
334 
335 	return size;
336 }
337 
338 static int nvme_auth_process_dhchap_success1(struct nvme_ctrl *ctrl,
339 		struct nvme_dhchap_queue_context *chap)
340 {
341 	struct nvmf_auth_dhchap_success1_data *data = chap->buf;
342 	size_t size = sizeof(*data) + chap->hash_len;
343 
344 	if (size > CHAP_BUF_SIZE) {
345 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
346 		return -EINVAL;
347 	}
348 
349 	if (data->hl != chap->hash_len) {
350 		dev_warn(ctrl->device,
351 			 "qid %d: invalid hash length %u\n",
352 			 chap->qid, data->hl);
353 		chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
354 		return -EPROTO;
355 	}
356 
357 	/* Just print out information for the admin queue */
358 	if (chap->qid == 0)
359 		dev_info(ctrl->device,
360 			 "qid 0: authenticated with hash %s dhgroup %s\n",
361 			 nvme_auth_hmac_name(chap->hash_id),
362 			 nvme_auth_dhgroup_name(chap->dhgroup_id));
363 
364 	if (!data->rvalid)
365 		return 0;
366 
367 	/* Validate controller response */
368 	if (memcmp(chap->response, data->rval, data->hl)) {
369 		dev_dbg(ctrl->device, "%s: qid %d ctrl response %*ph\n",
370 			__func__, chap->qid, (int)chap->hash_len, data->rval);
371 		dev_dbg(ctrl->device, "%s: qid %d host response %*ph\n",
372 			__func__, chap->qid, (int)chap->hash_len,
373 			chap->response);
374 		dev_warn(ctrl->device,
375 			 "qid %d: controller authentication failed\n",
376 			 chap->qid);
377 		chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
378 		return -ECONNREFUSED;
379 	}
380 
381 	/* Just print out information for the admin queue */
382 	if (chap->qid == 0)
383 		dev_info(ctrl->device,
384 			 "qid 0: controller authenticated\n");
385 	return 0;
386 }
387 
388 static int nvme_auth_set_dhchap_success2_data(struct nvme_ctrl *ctrl,
389 		struct nvme_dhchap_queue_context *chap)
390 {
391 	struct nvmf_auth_dhchap_success2_data *data = chap->buf;
392 	size_t size = sizeof(*data);
393 
394 	memset(chap->buf, 0, size);
395 	data->auth_type = NVME_AUTH_DHCHAP_MESSAGES;
396 	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_SUCCESS2;
397 	data->t_id = cpu_to_le16(chap->transaction);
398 
399 	return size;
400 }
401 
402 static int nvme_auth_set_dhchap_failure2_data(struct nvme_ctrl *ctrl,
403 		struct nvme_dhchap_queue_context *chap)
404 {
405 	struct nvmf_auth_dhchap_failure_data *data = chap->buf;
406 	size_t size = sizeof(*data);
407 
408 	memset(chap->buf, 0, size);
409 	data->auth_type = NVME_AUTH_COMMON_MESSAGES;
410 	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_FAILURE2;
411 	data->t_id = cpu_to_le16(chap->transaction);
412 	data->rescode = NVME_AUTH_DHCHAP_FAILURE_REASON_FAILED;
413 	data->rescode_exp = chap->status;
414 
415 	return size;
416 }
417 
418 static int nvme_auth_dhchap_setup_host_response(struct nvme_ctrl *ctrl,
419 		struct nvme_dhchap_queue_context *chap)
420 {
421 	SHASH_DESC_ON_STACK(shash, chap->shash_tfm);
422 	u8 buf[4], *challenge = chap->c1;
423 	int ret;
424 
425 	dev_dbg(ctrl->device, "%s: qid %d host response seq %u transaction %d\n",
426 		__func__, chap->qid, chap->s1, chap->transaction);
427 
428 	if (!chap->transformed_key) {
429 		chap->transformed_key = nvme_auth_transform_key(ctrl->host_key,
430 						ctrl->opts->host->nqn);
431 		if (IS_ERR(chap->transformed_key)) {
432 			ret = PTR_ERR(chap->transformed_key);
433 			chap->transformed_key = NULL;
434 			return ret;
435 		}
436 	} else {
437 		dev_dbg(ctrl->device, "%s: qid %d re-using host response\n",
438 			__func__, chap->qid);
439 	}
440 
441 	ret = crypto_shash_setkey(chap->shash_tfm,
442 			chap->transformed_key->key, chap->transformed_key->len);
443 	if (ret) {
444 		dev_warn(ctrl->device, "qid %d: failed to set key, error %d\n",
445 			 chap->qid, ret);
446 		goto out;
447 	}
448 
449 	if (chap->dh_tfm) {
450 		challenge = kmalloc(chap->hash_len, GFP_KERNEL);
451 		if (!challenge) {
452 			ret = -ENOMEM;
453 			goto out;
454 		}
455 		ret = nvme_auth_augmented_challenge(chap->hash_id,
456 						    chap->sess_key,
457 						    chap->sess_key_len,
458 						    chap->c1, challenge,
459 						    chap->hash_len);
460 		if (ret)
461 			goto out;
462 	}
463 
464 	shash->tfm = chap->shash_tfm;
465 	ret = crypto_shash_init(shash);
466 	if (ret)
467 		goto out;
468 	ret = crypto_shash_update(shash, challenge, chap->hash_len);
469 	if (ret)
470 		goto out;
471 	put_unaligned_le32(chap->s1, buf);
472 	ret = crypto_shash_update(shash, buf, 4);
473 	if (ret)
474 		goto out;
475 	put_unaligned_le16(chap->transaction, buf);
476 	ret = crypto_shash_update(shash, buf, 2);
477 	if (ret)
478 		goto out;
479 	memset(buf, 0, sizeof(buf));
480 	ret = crypto_shash_update(shash, buf, 1);
481 	if (ret)
482 		goto out;
483 	ret = crypto_shash_update(shash, "HostHost", 8);
484 	if (ret)
485 		goto out;
486 	ret = crypto_shash_update(shash, ctrl->opts->host->nqn,
487 				  strlen(ctrl->opts->host->nqn));
488 	if (ret)
489 		goto out;
490 	ret = crypto_shash_update(shash, buf, 1);
491 	if (ret)
492 		goto out;
493 	ret = crypto_shash_update(shash, ctrl->opts->subsysnqn,
494 			    strlen(ctrl->opts->subsysnqn));
495 	if (ret)
496 		goto out;
497 	ret = crypto_shash_final(shash, chap->response);
498 out:
499 	if (challenge != chap->c1)
500 		kfree(challenge);
501 	return ret;
502 }
503 
504 static int nvme_auth_dhchap_setup_ctrl_response(struct nvme_ctrl *ctrl,
505 		struct nvme_dhchap_queue_context *chap)
506 {
507 	SHASH_DESC_ON_STACK(shash, chap->shash_tfm);
508 	struct nvme_dhchap_key *transformed_key;
509 	u8 buf[4], *challenge = chap->c2;
510 	int ret;
511 
512 	transformed_key = nvme_auth_transform_key(ctrl->ctrl_key,
513 				ctrl->opts->subsysnqn);
514 	if (IS_ERR(transformed_key)) {
515 		ret = PTR_ERR(transformed_key);
516 		return ret;
517 	}
518 
519 	ret = crypto_shash_setkey(chap->shash_tfm,
520 			transformed_key->key, transformed_key->len);
521 	if (ret) {
522 		dev_warn(ctrl->device, "qid %d: failed to set key, error %d\n",
523 			 chap->qid, ret);
524 		goto out;
525 	}
526 
527 	if (chap->dh_tfm) {
528 		challenge = kmalloc(chap->hash_len, GFP_KERNEL);
529 		if (!challenge) {
530 			ret = -ENOMEM;
531 			goto out;
532 		}
533 		ret = nvme_auth_augmented_challenge(chap->hash_id,
534 						    chap->sess_key,
535 						    chap->sess_key_len,
536 						    chap->c2, challenge,
537 						    chap->hash_len);
538 		if (ret)
539 			goto out;
540 	}
541 	dev_dbg(ctrl->device, "%s: qid %d ctrl response seq %u transaction %d\n",
542 		__func__, chap->qid, chap->s2, chap->transaction);
543 	dev_dbg(ctrl->device, "%s: qid %d challenge %*ph\n",
544 		__func__, chap->qid, (int)chap->hash_len, challenge);
545 	dev_dbg(ctrl->device, "%s: qid %d subsysnqn %s\n",
546 		__func__, chap->qid, ctrl->opts->subsysnqn);
547 	dev_dbg(ctrl->device, "%s: qid %d hostnqn %s\n",
548 		__func__, chap->qid, ctrl->opts->host->nqn);
549 	shash->tfm = chap->shash_tfm;
550 	ret = crypto_shash_init(shash);
551 	if (ret)
552 		goto out;
553 	ret = crypto_shash_update(shash, challenge, chap->hash_len);
554 	if (ret)
555 		goto out;
556 	put_unaligned_le32(chap->s2, buf);
557 	ret = crypto_shash_update(shash, buf, 4);
558 	if (ret)
559 		goto out;
560 	put_unaligned_le16(chap->transaction, buf);
561 	ret = crypto_shash_update(shash, buf, 2);
562 	if (ret)
563 		goto out;
564 	memset(buf, 0, 4);
565 	ret = crypto_shash_update(shash, buf, 1);
566 	if (ret)
567 		goto out;
568 	ret = crypto_shash_update(shash, "Controller", 10);
569 	if (ret)
570 		goto out;
571 	ret = crypto_shash_update(shash, ctrl->opts->subsysnqn,
572 				  strlen(ctrl->opts->subsysnqn));
573 	if (ret)
574 		goto out;
575 	ret = crypto_shash_update(shash, buf, 1);
576 	if (ret)
577 		goto out;
578 	ret = crypto_shash_update(shash, ctrl->opts->host->nqn,
579 				  strlen(ctrl->opts->host->nqn));
580 	if (ret)
581 		goto out;
582 	ret = crypto_shash_final(shash, chap->response);
583 out:
584 	if (challenge != chap->c2)
585 		kfree(challenge);
586 	nvme_auth_free_key(transformed_key);
587 	return ret;
588 }
589 
590 static int nvme_auth_dhchap_exponential(struct nvme_ctrl *ctrl,
591 		struct nvme_dhchap_queue_context *chap)
592 {
593 	int ret;
594 
595 	if (chap->host_key && chap->host_key_len) {
596 		dev_dbg(ctrl->device,
597 			"qid %d: reusing host key\n", chap->qid);
598 		goto gen_sesskey;
599 	}
600 	ret = nvme_auth_gen_privkey(chap->dh_tfm, chap->dhgroup_id);
601 	if (ret < 0) {
602 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
603 		return ret;
604 	}
605 
606 	chap->host_key_len = crypto_kpp_maxsize(chap->dh_tfm);
607 
608 	chap->host_key = kzalloc(chap->host_key_len, GFP_KERNEL);
609 	if (!chap->host_key) {
610 		chap->host_key_len = 0;
611 		chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
612 		return -ENOMEM;
613 	}
614 	ret = nvme_auth_gen_pubkey(chap->dh_tfm,
615 				   chap->host_key, chap->host_key_len);
616 	if (ret) {
617 		dev_dbg(ctrl->device,
618 			"failed to generate public key, error %d\n", ret);
619 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
620 		return ret;
621 	}
622 
623 gen_sesskey:
624 	chap->sess_key_len = chap->host_key_len;
625 	chap->sess_key = kmalloc(chap->sess_key_len, GFP_KERNEL);
626 	if (!chap->sess_key) {
627 		chap->sess_key_len = 0;
628 		chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
629 		return -ENOMEM;
630 	}
631 
632 	ret = nvme_auth_gen_shared_secret(chap->dh_tfm,
633 					  chap->ctrl_key, chap->ctrl_key_len,
634 					  chap->sess_key, chap->sess_key_len);
635 	if (ret) {
636 		dev_dbg(ctrl->device,
637 			"failed to generate shared secret, error %d\n", ret);
638 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
639 		return ret;
640 	}
641 	dev_dbg(ctrl->device, "shared secret %*ph\n",
642 		(int)chap->sess_key_len, chap->sess_key);
643 	return 0;
644 }
645 
646 static void nvme_auth_reset_dhchap(struct nvme_dhchap_queue_context *chap)
647 {
648 	nvme_auth_free_key(chap->transformed_key);
649 	chap->transformed_key = NULL;
650 	kfree_sensitive(chap->host_key);
651 	chap->host_key = NULL;
652 	chap->host_key_len = 0;
653 	kfree_sensitive(chap->ctrl_key);
654 	chap->ctrl_key = NULL;
655 	chap->ctrl_key_len = 0;
656 	kfree_sensitive(chap->sess_key);
657 	chap->sess_key = NULL;
658 	chap->sess_key_len = 0;
659 	chap->status = 0;
660 	chap->error = 0;
661 	chap->s1 = 0;
662 	chap->s2 = 0;
663 	chap->bi_directional = false;
664 	chap->transaction = 0;
665 	memset(chap->c1, 0, sizeof(chap->c1));
666 	memset(chap->c2, 0, sizeof(chap->c2));
667 	mempool_free(chap->buf, nvme_chap_buf_pool);
668 	chap->buf = NULL;
669 }
670 
671 static void nvme_auth_free_dhchap(struct nvme_dhchap_queue_context *chap)
672 {
673 	nvme_auth_reset_dhchap(chap);
674 	if (chap->shash_tfm)
675 		crypto_free_shash(chap->shash_tfm);
676 	if (chap->dh_tfm)
677 		crypto_free_kpp(chap->dh_tfm);
678 }
679 
680 static void nvme_queue_auth_work(struct work_struct *work)
681 {
682 	struct nvme_dhchap_queue_context *chap =
683 		container_of(work, struct nvme_dhchap_queue_context, auth_work);
684 	struct nvme_ctrl *ctrl = chap->ctrl;
685 	size_t tl;
686 	int ret = 0;
687 
688 	/*
689 	 * Allocate a large enough buffer for the entire negotiation:
690 	 * 4k is enough to ffdhe8192.
691 	 */
692 	chap->buf = mempool_alloc(nvme_chap_buf_pool, GFP_KERNEL);
693 	if (!chap->buf) {
694 		chap->error = -ENOMEM;
695 		return;
696 	}
697 
698 	chap->transaction = ctrl->transaction++;
699 
700 	/* DH-HMAC-CHAP Step 1: send negotiate */
701 	dev_dbg(ctrl->device, "%s: qid %d send negotiate\n",
702 		__func__, chap->qid);
703 	ret = nvme_auth_set_dhchap_negotiate_data(ctrl, chap);
704 	if (ret < 0) {
705 		chap->error = ret;
706 		return;
707 	}
708 	tl = ret;
709 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
710 	if (ret) {
711 		chap->error = ret;
712 		return;
713 	}
714 
715 	/* DH-HMAC-CHAP Step 2: receive challenge */
716 	dev_dbg(ctrl->device, "%s: qid %d receive challenge\n",
717 		__func__, chap->qid);
718 
719 	memset(chap->buf, 0, CHAP_BUF_SIZE);
720 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, CHAP_BUF_SIZE,
721 			       false);
722 	if (ret) {
723 		dev_warn(ctrl->device,
724 			 "qid %d failed to receive challenge, %s %d\n",
725 			 chap->qid, ret < 0 ? "error" : "nvme status", ret);
726 		chap->error = ret;
727 		return;
728 	}
729 	ret = nvme_auth_receive_validate(ctrl, chap->qid, chap->buf, chap->transaction,
730 					 NVME_AUTH_DHCHAP_MESSAGE_CHALLENGE);
731 	if (ret) {
732 		chap->status = ret;
733 		chap->error = -EKEYREJECTED;
734 		return;
735 	}
736 
737 	ret = nvme_auth_process_dhchap_challenge(ctrl, chap);
738 	if (ret) {
739 		/* Invalid challenge parameters */
740 		chap->error = ret;
741 		goto fail2;
742 	}
743 
744 	if (chap->ctrl_key_len) {
745 		dev_dbg(ctrl->device,
746 			"%s: qid %d DH exponential\n",
747 			__func__, chap->qid);
748 		ret = nvme_auth_dhchap_exponential(ctrl, chap);
749 		if (ret) {
750 			chap->error = ret;
751 			goto fail2;
752 		}
753 	}
754 
755 	dev_dbg(ctrl->device, "%s: qid %d host response\n",
756 		__func__, chap->qid);
757 	mutex_lock(&ctrl->dhchap_auth_mutex);
758 	ret = nvme_auth_dhchap_setup_host_response(ctrl, chap);
759 	mutex_unlock(&ctrl->dhchap_auth_mutex);
760 	if (ret) {
761 		chap->error = ret;
762 		goto fail2;
763 	}
764 
765 	/* DH-HMAC-CHAP Step 3: send reply */
766 	dev_dbg(ctrl->device, "%s: qid %d send reply\n",
767 		__func__, chap->qid);
768 	ret = nvme_auth_set_dhchap_reply_data(ctrl, chap);
769 	if (ret < 0) {
770 		chap->error = ret;
771 		goto fail2;
772 	}
773 
774 	tl = ret;
775 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
776 	if (ret) {
777 		chap->error = ret;
778 		goto fail2;
779 	}
780 
781 	/* DH-HMAC-CHAP Step 4: receive success1 */
782 	dev_dbg(ctrl->device, "%s: qid %d receive success1\n",
783 		__func__, chap->qid);
784 
785 	memset(chap->buf, 0, CHAP_BUF_SIZE);
786 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, CHAP_BUF_SIZE,
787 			       false);
788 	if (ret) {
789 		dev_warn(ctrl->device,
790 			 "qid %d failed to receive success1, %s %d\n",
791 			 chap->qid, ret < 0 ? "error" : "nvme status", ret);
792 		chap->error = ret;
793 		return;
794 	}
795 	ret = nvme_auth_receive_validate(ctrl, chap->qid,
796 					 chap->buf, chap->transaction,
797 					 NVME_AUTH_DHCHAP_MESSAGE_SUCCESS1);
798 	if (ret) {
799 		chap->status = ret;
800 		chap->error = -EKEYREJECTED;
801 		return;
802 	}
803 
804 	mutex_lock(&ctrl->dhchap_auth_mutex);
805 	if (ctrl->ctrl_key) {
806 		dev_dbg(ctrl->device,
807 			"%s: qid %d controller response\n",
808 			__func__, chap->qid);
809 		ret = nvme_auth_dhchap_setup_ctrl_response(ctrl, chap);
810 		if (ret) {
811 			mutex_unlock(&ctrl->dhchap_auth_mutex);
812 			chap->error = ret;
813 			goto fail2;
814 		}
815 	}
816 	mutex_unlock(&ctrl->dhchap_auth_mutex);
817 
818 	ret = nvme_auth_process_dhchap_success1(ctrl, chap);
819 	if (ret) {
820 		/* Controller authentication failed */
821 		chap->error = -EKEYREJECTED;
822 		goto fail2;
823 	}
824 
825 	if (chap->bi_directional) {
826 		/* DH-HMAC-CHAP Step 5: send success2 */
827 		dev_dbg(ctrl->device, "%s: qid %d send success2\n",
828 			__func__, chap->qid);
829 		tl = nvme_auth_set_dhchap_success2_data(ctrl, chap);
830 		ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
831 		if (ret)
832 			chap->error = ret;
833 	}
834 	if (!ret) {
835 		chap->error = 0;
836 		return;
837 	}
838 
839 fail2:
840 	if (chap->status == 0)
841 		chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
842 	dev_dbg(ctrl->device, "%s: qid %d send failure2, status %x\n",
843 		__func__, chap->qid, chap->status);
844 	tl = nvme_auth_set_dhchap_failure2_data(ctrl, chap);
845 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
846 	/*
847 	 * only update error if send failure2 failed and no other
848 	 * error had been set during authentication.
849 	 */
850 	if (ret && !chap->error)
851 		chap->error = ret;
852 }
853 
854 int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid)
855 {
856 	struct nvme_dhchap_queue_context *chap;
857 
858 	if (!ctrl->host_key) {
859 		dev_warn(ctrl->device, "qid %d: no key\n", qid);
860 		return -ENOKEY;
861 	}
862 
863 	if (ctrl->opts->dhchap_ctrl_secret && !ctrl->ctrl_key) {
864 		dev_warn(ctrl->device, "qid %d: invalid ctrl key\n", qid);
865 		return -ENOKEY;
866 	}
867 
868 	chap = &ctrl->dhchap_ctxs[qid];
869 	cancel_work_sync(&chap->auth_work);
870 	queue_work(nvme_auth_wq, &chap->auth_work);
871 	return 0;
872 }
873 EXPORT_SYMBOL_GPL(nvme_auth_negotiate);
874 
875 int nvme_auth_wait(struct nvme_ctrl *ctrl, int qid)
876 {
877 	struct nvme_dhchap_queue_context *chap;
878 	int ret;
879 
880 	chap = &ctrl->dhchap_ctxs[qid];
881 	flush_work(&chap->auth_work);
882 	ret = chap->error;
883 	/* clear sensitive info */
884 	nvme_auth_reset_dhchap(chap);
885 	return ret;
886 }
887 EXPORT_SYMBOL_GPL(nvme_auth_wait);
888 
889 static void nvme_ctrl_auth_work(struct work_struct *work)
890 {
891 	struct nvme_ctrl *ctrl =
892 		container_of(work, struct nvme_ctrl, dhchap_auth_work);
893 	int ret, q;
894 
895 	/*
896 	 * If the ctrl is no connected, bail as reconnect will handle
897 	 * authentication.
898 	 */
899 	if (nvme_ctrl_state(ctrl) != NVME_CTRL_LIVE)
900 		return;
901 
902 	/* Authenticate admin queue first */
903 	ret = nvme_auth_negotiate(ctrl, 0);
904 	if (ret) {
905 		dev_warn(ctrl->device,
906 			 "qid 0: error %d setting up authentication\n", ret);
907 		return;
908 	}
909 	ret = nvme_auth_wait(ctrl, 0);
910 	if (ret) {
911 		dev_warn(ctrl->device,
912 			 "qid 0: authentication failed\n");
913 		return;
914 	}
915 
916 	for (q = 1; q < ctrl->queue_count; q++) {
917 		ret = nvme_auth_negotiate(ctrl, q);
918 		if (ret) {
919 			dev_warn(ctrl->device,
920 				 "qid %d: error %d setting up authentication\n",
921 				 q, ret);
922 			break;
923 		}
924 	}
925 
926 	/*
927 	 * Failure is a soft-state; credentials remain valid until
928 	 * the controller terminates the connection.
929 	 */
930 	for (q = 1; q < ctrl->queue_count; q++) {
931 		ret = nvme_auth_wait(ctrl, q);
932 		if (ret)
933 			dev_warn(ctrl->device,
934 				 "qid %d: authentication failed\n", q);
935 	}
936 }
937 
938 int nvme_auth_init_ctrl(struct nvme_ctrl *ctrl)
939 {
940 	struct nvme_dhchap_queue_context *chap;
941 	int i, ret;
942 
943 	mutex_init(&ctrl->dhchap_auth_mutex);
944 	INIT_WORK(&ctrl->dhchap_auth_work, nvme_ctrl_auth_work);
945 	if (!ctrl->opts)
946 		return 0;
947 	ret = nvme_auth_generate_key(ctrl->opts->dhchap_secret,
948 			&ctrl->host_key);
949 	if (ret)
950 		return ret;
951 	ret = nvme_auth_generate_key(ctrl->opts->dhchap_ctrl_secret,
952 			&ctrl->ctrl_key);
953 	if (ret)
954 		goto err_free_dhchap_secret;
955 
956 	if (!ctrl->opts->dhchap_secret && !ctrl->opts->dhchap_ctrl_secret)
957 		return 0;
958 
959 	ctrl->dhchap_ctxs = kvcalloc(ctrl_max_dhchaps(ctrl),
960 				sizeof(*chap), GFP_KERNEL);
961 	if (!ctrl->dhchap_ctxs) {
962 		ret = -ENOMEM;
963 		goto err_free_dhchap_ctrl_secret;
964 	}
965 
966 	for (i = 0; i < ctrl_max_dhchaps(ctrl); i++) {
967 		chap = &ctrl->dhchap_ctxs[i];
968 		chap->qid = i;
969 		chap->ctrl = ctrl;
970 		INIT_WORK(&chap->auth_work, nvme_queue_auth_work);
971 	}
972 
973 	return 0;
974 err_free_dhchap_ctrl_secret:
975 	nvme_auth_free_key(ctrl->ctrl_key);
976 	ctrl->ctrl_key = NULL;
977 err_free_dhchap_secret:
978 	nvme_auth_free_key(ctrl->host_key);
979 	ctrl->host_key = NULL;
980 	return ret;
981 }
982 EXPORT_SYMBOL_GPL(nvme_auth_init_ctrl);
983 
984 void nvme_auth_stop(struct nvme_ctrl *ctrl)
985 {
986 	cancel_work_sync(&ctrl->dhchap_auth_work);
987 }
988 EXPORT_SYMBOL_GPL(nvme_auth_stop);
989 
990 void nvme_auth_free(struct nvme_ctrl *ctrl)
991 {
992 	int i;
993 
994 	if (ctrl->dhchap_ctxs) {
995 		for (i = 0; i < ctrl_max_dhchaps(ctrl); i++)
996 			nvme_auth_free_dhchap(&ctrl->dhchap_ctxs[i]);
997 		kfree(ctrl->dhchap_ctxs);
998 	}
999 	if (ctrl->host_key) {
1000 		nvme_auth_free_key(ctrl->host_key);
1001 		ctrl->host_key = NULL;
1002 	}
1003 	if (ctrl->ctrl_key) {
1004 		nvme_auth_free_key(ctrl->ctrl_key);
1005 		ctrl->ctrl_key = NULL;
1006 	}
1007 }
1008 EXPORT_SYMBOL_GPL(nvme_auth_free);
1009 
1010 int __init nvme_init_auth(void)
1011 {
1012 	nvme_auth_wq = alloc_workqueue("nvme-auth-wq",
1013 			       WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 0);
1014 	if (!nvme_auth_wq)
1015 		return -ENOMEM;
1016 
1017 	nvme_chap_buf_cache = kmem_cache_create("nvme-chap-buf-cache",
1018 				CHAP_BUF_SIZE, 0, SLAB_HWCACHE_ALIGN, NULL);
1019 	if (!nvme_chap_buf_cache)
1020 		goto err_destroy_workqueue;
1021 
1022 	nvme_chap_buf_pool = mempool_create(16, mempool_alloc_slab,
1023 			mempool_free_slab, nvme_chap_buf_cache);
1024 	if (!nvme_chap_buf_pool)
1025 		goto err_destroy_chap_buf_cache;
1026 
1027 	return 0;
1028 err_destroy_chap_buf_cache:
1029 	kmem_cache_destroy(nvme_chap_buf_cache);
1030 err_destroy_workqueue:
1031 	destroy_workqueue(nvme_auth_wq);
1032 	return -ENOMEM;
1033 }
1034 
1035 void __exit nvme_exit_auth(void)
1036 {
1037 	mempool_destroy(nvme_chap_buf_pool);
1038 	kmem_cache_destroy(nvme_chap_buf_cache);
1039 	destroy_workqueue(nvme_auth_wq);
1040 }
1041