xref: /openbmc/linux/drivers/nvme/host/auth.c (revision 287dcc2b)
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 <asm/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 	void *buf;
27 	int qid;
28 	int error;
29 	u32 s1;
30 	u32 s2;
31 	u16 transaction;
32 	u8 status;
33 	u8 hash_id;
34 	size_t hash_len;
35 	u8 dhgroup_id;
36 	u8 c1[64];
37 	u8 c2[64];
38 	u8 response[64];
39 	u8 *host_response;
40 	u8 *ctrl_key;
41 	int ctrl_key_len;
42 	u8 *host_key;
43 	int host_key_len;
44 	u8 *sess_key;
45 	int sess_key_len;
46 };
47 
48 static struct workqueue_struct *nvme_auth_wq;
49 
50 #define nvme_auth_flags_from_qid(qid) \
51 	(qid == 0) ? 0 : BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED
52 #define nvme_auth_queue_from_qid(ctrl, qid) \
53 	(qid == 0) ? (ctrl)->fabrics_q : (ctrl)->connect_q
54 
55 static inline int ctrl_max_dhchaps(struct nvme_ctrl *ctrl)
56 {
57 	return ctrl->opts->nr_io_queues + ctrl->opts->nr_write_queues +
58 			ctrl->opts->nr_poll_queues + 1;
59 }
60 
61 static int nvme_auth_submit(struct nvme_ctrl *ctrl, int qid,
62 			    void *data, size_t data_len, bool auth_send)
63 {
64 	struct nvme_command cmd = {};
65 	blk_mq_req_flags_t flags = nvme_auth_flags_from_qid(qid);
66 	struct request_queue *q = nvme_auth_queue_from_qid(ctrl, qid);
67 	int ret;
68 
69 	cmd.auth_common.opcode = nvme_fabrics_command;
70 	cmd.auth_common.secp = NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER;
71 	cmd.auth_common.spsp0 = 0x01;
72 	cmd.auth_common.spsp1 = 0x01;
73 	if (auth_send) {
74 		cmd.auth_send.fctype = nvme_fabrics_type_auth_send;
75 		cmd.auth_send.tl = cpu_to_le32(data_len);
76 	} else {
77 		cmd.auth_receive.fctype = nvme_fabrics_type_auth_receive;
78 		cmd.auth_receive.al = cpu_to_le32(data_len);
79 	}
80 
81 	ret = __nvme_submit_sync_cmd(q, &cmd, NULL, data, data_len,
82 				     qid == 0 ? NVME_QID_ANY : qid,
83 				     0, 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 		get_random_bytes(chap->c2, chap->hash_len);
316 		data->cvalid = 1;
317 		chap->s2 = nvme_auth_get_seqnum();
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 		chap->s2 = 0;
325 	}
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);
343 
344 	if (chap->ctrl_key)
345 		size += chap->hash_len;
346 
347 	if (size > CHAP_BUF_SIZE) {
348 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
349 		return -EINVAL;
350 	}
351 
352 	if (data->hl != chap->hash_len) {
353 		dev_warn(ctrl->device,
354 			 "qid %d: invalid hash length %u\n",
355 			 chap->qid, data->hl);
356 		chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
357 		return -EPROTO;
358 	}
359 
360 	/* Just print out information for the admin queue */
361 	if (chap->qid == 0)
362 		dev_info(ctrl->device,
363 			 "qid 0: authenticated with hash %s dhgroup %s\n",
364 			 nvme_auth_hmac_name(chap->hash_id),
365 			 nvme_auth_dhgroup_name(chap->dhgroup_id));
366 
367 	if (!data->rvalid)
368 		return 0;
369 
370 	/* Validate controller response */
371 	if (memcmp(chap->response, data->rval, data->hl)) {
372 		dev_dbg(ctrl->device, "%s: qid %d ctrl response %*ph\n",
373 			__func__, chap->qid, (int)chap->hash_len, data->rval);
374 		dev_dbg(ctrl->device, "%s: qid %d host response %*ph\n",
375 			__func__, chap->qid, (int)chap->hash_len,
376 			chap->response);
377 		dev_warn(ctrl->device,
378 			 "qid %d: controller authentication failed\n",
379 			 chap->qid);
380 		chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
381 		return -ECONNREFUSED;
382 	}
383 
384 	/* Just print out information for the admin queue */
385 	if (chap->qid == 0)
386 		dev_info(ctrl->device,
387 			 "qid 0: controller authenticated\n");
388 	return 0;
389 }
390 
391 static int nvme_auth_set_dhchap_success2_data(struct nvme_ctrl *ctrl,
392 		struct nvme_dhchap_queue_context *chap)
393 {
394 	struct nvmf_auth_dhchap_success2_data *data = chap->buf;
395 	size_t size = sizeof(*data);
396 
397 	memset(chap->buf, 0, size);
398 	data->auth_type = NVME_AUTH_DHCHAP_MESSAGES;
399 	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_SUCCESS2;
400 	data->t_id = cpu_to_le16(chap->transaction);
401 
402 	return size;
403 }
404 
405 static int nvme_auth_set_dhchap_failure2_data(struct nvme_ctrl *ctrl,
406 		struct nvme_dhchap_queue_context *chap)
407 {
408 	struct nvmf_auth_dhchap_failure_data *data = chap->buf;
409 	size_t size = sizeof(*data);
410 
411 	memset(chap->buf, 0, size);
412 	data->auth_type = NVME_AUTH_COMMON_MESSAGES;
413 	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_FAILURE2;
414 	data->t_id = cpu_to_le16(chap->transaction);
415 	data->rescode = NVME_AUTH_DHCHAP_FAILURE_REASON_FAILED;
416 	data->rescode_exp = chap->status;
417 
418 	return size;
419 }
420 
421 static int nvme_auth_dhchap_setup_host_response(struct nvme_ctrl *ctrl,
422 		struct nvme_dhchap_queue_context *chap)
423 {
424 	SHASH_DESC_ON_STACK(shash, chap->shash_tfm);
425 	u8 buf[4], *challenge = chap->c1;
426 	int ret;
427 
428 	dev_dbg(ctrl->device, "%s: qid %d host response seq %u transaction %d\n",
429 		__func__, chap->qid, chap->s1, chap->transaction);
430 
431 	if (!chap->host_response) {
432 		chap->host_response = nvme_auth_transform_key(ctrl->host_key,
433 						ctrl->opts->host->nqn);
434 		if (IS_ERR(chap->host_response)) {
435 			ret = PTR_ERR(chap->host_response);
436 			chap->host_response = NULL;
437 			return ret;
438 		}
439 	} else {
440 		dev_dbg(ctrl->device, "%s: qid %d re-using host response\n",
441 			__func__, chap->qid);
442 	}
443 
444 	ret = crypto_shash_setkey(chap->shash_tfm,
445 			chap->host_response, ctrl->host_key->len);
446 	if (ret) {
447 		dev_warn(ctrl->device, "qid %d: failed to set key, error %d\n",
448 			 chap->qid, ret);
449 		goto out;
450 	}
451 
452 	if (chap->dh_tfm) {
453 		challenge = kmalloc(chap->hash_len, GFP_KERNEL);
454 		if (!challenge) {
455 			ret = -ENOMEM;
456 			goto out;
457 		}
458 		ret = nvme_auth_augmented_challenge(chap->hash_id,
459 						    chap->sess_key,
460 						    chap->sess_key_len,
461 						    chap->c1, challenge,
462 						    chap->hash_len);
463 		if (ret)
464 			goto out;
465 	}
466 
467 	shash->tfm = chap->shash_tfm;
468 	ret = crypto_shash_init(shash);
469 	if (ret)
470 		goto out;
471 	ret = crypto_shash_update(shash, challenge, chap->hash_len);
472 	if (ret)
473 		goto out;
474 	put_unaligned_le32(chap->s1, buf);
475 	ret = crypto_shash_update(shash, buf, 4);
476 	if (ret)
477 		goto out;
478 	put_unaligned_le16(chap->transaction, buf);
479 	ret = crypto_shash_update(shash, buf, 2);
480 	if (ret)
481 		goto out;
482 	memset(buf, 0, sizeof(buf));
483 	ret = crypto_shash_update(shash, buf, 1);
484 	if (ret)
485 		goto out;
486 	ret = crypto_shash_update(shash, "HostHost", 8);
487 	if (ret)
488 		goto out;
489 	ret = crypto_shash_update(shash, ctrl->opts->host->nqn,
490 				  strlen(ctrl->opts->host->nqn));
491 	if (ret)
492 		goto out;
493 	ret = crypto_shash_update(shash, buf, 1);
494 	if (ret)
495 		goto out;
496 	ret = crypto_shash_update(shash, ctrl->opts->subsysnqn,
497 			    strlen(ctrl->opts->subsysnqn));
498 	if (ret)
499 		goto out;
500 	ret = crypto_shash_final(shash, chap->response);
501 out:
502 	if (challenge != chap->c1)
503 		kfree(challenge);
504 	return ret;
505 }
506 
507 static int nvme_auth_dhchap_setup_ctrl_response(struct nvme_ctrl *ctrl,
508 		struct nvme_dhchap_queue_context *chap)
509 {
510 	SHASH_DESC_ON_STACK(shash, chap->shash_tfm);
511 	u8 *ctrl_response;
512 	u8 buf[4], *challenge = chap->c2;
513 	int ret;
514 
515 	ctrl_response = nvme_auth_transform_key(ctrl->ctrl_key,
516 				ctrl->opts->subsysnqn);
517 	if (IS_ERR(ctrl_response)) {
518 		ret = PTR_ERR(ctrl_response);
519 		return ret;
520 	}
521 
522 	ret = crypto_shash_setkey(chap->shash_tfm,
523 			ctrl_response, ctrl->ctrl_key->len);
524 	if (ret) {
525 		dev_warn(ctrl->device, "qid %d: failed to set key, error %d\n",
526 			 chap->qid, ret);
527 		goto out;
528 	}
529 
530 	if (chap->dh_tfm) {
531 		challenge = kmalloc(chap->hash_len, GFP_KERNEL);
532 		if (!challenge) {
533 			ret = -ENOMEM;
534 			goto out;
535 		}
536 		ret = nvme_auth_augmented_challenge(chap->hash_id,
537 						    chap->sess_key,
538 						    chap->sess_key_len,
539 						    chap->c2, challenge,
540 						    chap->hash_len);
541 		if (ret)
542 			goto out;
543 	}
544 	dev_dbg(ctrl->device, "%s: qid %d ctrl response seq %u transaction %d\n",
545 		__func__, chap->qid, chap->s2, chap->transaction);
546 	dev_dbg(ctrl->device, "%s: qid %d challenge %*ph\n",
547 		__func__, chap->qid, (int)chap->hash_len, challenge);
548 	dev_dbg(ctrl->device, "%s: qid %d subsysnqn %s\n",
549 		__func__, chap->qid, ctrl->opts->subsysnqn);
550 	dev_dbg(ctrl->device, "%s: qid %d hostnqn %s\n",
551 		__func__, chap->qid, ctrl->opts->host->nqn);
552 	shash->tfm = chap->shash_tfm;
553 	ret = crypto_shash_init(shash);
554 	if (ret)
555 		goto out;
556 	ret = crypto_shash_update(shash, challenge, chap->hash_len);
557 	if (ret)
558 		goto out;
559 	put_unaligned_le32(chap->s2, buf);
560 	ret = crypto_shash_update(shash, buf, 4);
561 	if (ret)
562 		goto out;
563 	put_unaligned_le16(chap->transaction, buf);
564 	ret = crypto_shash_update(shash, buf, 2);
565 	if (ret)
566 		goto out;
567 	memset(buf, 0, 4);
568 	ret = crypto_shash_update(shash, buf, 1);
569 	if (ret)
570 		goto out;
571 	ret = crypto_shash_update(shash, "Controller", 10);
572 	if (ret)
573 		goto out;
574 	ret = crypto_shash_update(shash, ctrl->opts->subsysnqn,
575 				  strlen(ctrl->opts->subsysnqn));
576 	if (ret)
577 		goto out;
578 	ret = crypto_shash_update(shash, buf, 1);
579 	if (ret)
580 		goto out;
581 	ret = crypto_shash_update(shash, ctrl->opts->host->nqn,
582 				  strlen(ctrl->opts->host->nqn));
583 	if (ret)
584 		goto out;
585 	ret = crypto_shash_final(shash, chap->response);
586 out:
587 	if (challenge != chap->c2)
588 		kfree(challenge);
589 	kfree(ctrl_response);
590 	return ret;
591 }
592 
593 static int nvme_auth_dhchap_exponential(struct nvme_ctrl *ctrl,
594 		struct nvme_dhchap_queue_context *chap)
595 {
596 	int ret;
597 
598 	if (chap->host_key && chap->host_key_len) {
599 		dev_dbg(ctrl->device,
600 			"qid %d: reusing host key\n", chap->qid);
601 		goto gen_sesskey;
602 	}
603 	ret = nvme_auth_gen_privkey(chap->dh_tfm, chap->dhgroup_id);
604 	if (ret < 0) {
605 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
606 		return ret;
607 	}
608 
609 	chap->host_key_len = crypto_kpp_maxsize(chap->dh_tfm);
610 
611 	chap->host_key = kzalloc(chap->host_key_len, GFP_KERNEL);
612 	if (!chap->host_key) {
613 		chap->host_key_len = 0;
614 		chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
615 		return -ENOMEM;
616 	}
617 	ret = nvme_auth_gen_pubkey(chap->dh_tfm,
618 				   chap->host_key, chap->host_key_len);
619 	if (ret) {
620 		dev_dbg(ctrl->device,
621 			"failed to generate public key, error %d\n", ret);
622 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
623 		return ret;
624 	}
625 
626 gen_sesskey:
627 	chap->sess_key_len = chap->host_key_len;
628 	chap->sess_key = kmalloc(chap->sess_key_len, GFP_KERNEL);
629 	if (!chap->sess_key) {
630 		chap->sess_key_len = 0;
631 		chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
632 		return -ENOMEM;
633 	}
634 
635 	ret = nvme_auth_gen_shared_secret(chap->dh_tfm,
636 					  chap->ctrl_key, chap->ctrl_key_len,
637 					  chap->sess_key, chap->sess_key_len);
638 	if (ret) {
639 		dev_dbg(ctrl->device,
640 			"failed to generate shared secret, error %d\n", ret);
641 		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
642 		return ret;
643 	}
644 	dev_dbg(ctrl->device, "shared secret %*ph\n",
645 		(int)chap->sess_key_len, chap->sess_key);
646 	return 0;
647 }
648 
649 static void nvme_auth_reset_dhchap(struct nvme_dhchap_queue_context *chap)
650 {
651 	kfree_sensitive(chap->host_response);
652 	chap->host_response = NULL;
653 	kfree_sensitive(chap->host_key);
654 	chap->host_key = NULL;
655 	chap->host_key_len = 0;
656 	kfree_sensitive(chap->ctrl_key);
657 	chap->ctrl_key = NULL;
658 	chap->ctrl_key_len = 0;
659 	kfree_sensitive(chap->sess_key);
660 	chap->sess_key = NULL;
661 	chap->sess_key_len = 0;
662 	chap->status = 0;
663 	chap->error = 0;
664 	chap->s1 = 0;
665 	chap->s2 = 0;
666 	chap->transaction = 0;
667 	memset(chap->c1, 0, sizeof(chap->c1));
668 	memset(chap->c2, 0, sizeof(chap->c2));
669 	mempool_free(chap->buf, nvme_chap_buf_pool);
670 	chap->buf = NULL;
671 }
672 
673 static void nvme_auth_free_dhchap(struct nvme_dhchap_queue_context *chap)
674 {
675 	nvme_auth_reset_dhchap(chap);
676 	if (chap->shash_tfm)
677 		crypto_free_shash(chap->shash_tfm);
678 	if (chap->dh_tfm)
679 		crypto_free_kpp(chap->dh_tfm);
680 }
681 
682 static void nvme_queue_auth_work(struct work_struct *work)
683 {
684 	struct nvme_dhchap_queue_context *chap =
685 		container_of(work, struct nvme_dhchap_queue_context, auth_work);
686 	struct nvme_ctrl *ctrl = chap->ctrl;
687 	size_t tl;
688 	int ret = 0;
689 
690 	/*
691 	 * Allocate a large enough buffer for the entire negotiation:
692 	 * 4k is enough to ffdhe8192.
693 	 */
694 	chap->buf = mempool_alloc(nvme_chap_buf_pool, GFP_KERNEL);
695 	if (!chap->buf) {
696 		chap->error = -ENOMEM;
697 		return;
698 	}
699 
700 	chap->transaction = ctrl->transaction++;
701 
702 	/* DH-HMAC-CHAP Step 1: send negotiate */
703 	dev_dbg(ctrl->device, "%s: qid %d send negotiate\n",
704 		__func__, chap->qid);
705 	ret = nvme_auth_set_dhchap_negotiate_data(ctrl, chap);
706 	if (ret < 0) {
707 		chap->error = ret;
708 		return;
709 	}
710 	tl = ret;
711 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
712 	if (ret) {
713 		chap->error = ret;
714 		return;
715 	}
716 
717 	/* DH-HMAC-CHAP Step 2: receive challenge */
718 	dev_dbg(ctrl->device, "%s: qid %d receive challenge\n",
719 		__func__, chap->qid);
720 
721 	memset(chap->buf, 0, CHAP_BUF_SIZE);
722 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, CHAP_BUF_SIZE,
723 			       false);
724 	if (ret) {
725 		dev_warn(ctrl->device,
726 			 "qid %d failed to receive challenge, %s %d\n",
727 			 chap->qid, ret < 0 ? "error" : "nvme status", ret);
728 		chap->error = ret;
729 		return;
730 	}
731 	ret = nvme_auth_receive_validate(ctrl, chap->qid, chap->buf, chap->transaction,
732 					 NVME_AUTH_DHCHAP_MESSAGE_CHALLENGE);
733 	if (ret) {
734 		chap->status = ret;
735 		chap->error = -ECONNREFUSED;
736 		return;
737 	}
738 
739 	ret = nvme_auth_process_dhchap_challenge(ctrl, chap);
740 	if (ret) {
741 		/* Invalid challenge parameters */
742 		chap->error = ret;
743 		goto fail2;
744 	}
745 
746 	if (chap->ctrl_key_len) {
747 		dev_dbg(ctrl->device,
748 			"%s: qid %d DH exponential\n",
749 			__func__, chap->qid);
750 		ret = nvme_auth_dhchap_exponential(ctrl, chap);
751 		if (ret) {
752 			chap->error = ret;
753 			goto fail2;
754 		}
755 	}
756 
757 	dev_dbg(ctrl->device, "%s: qid %d host response\n",
758 		__func__, chap->qid);
759 	mutex_lock(&ctrl->dhchap_auth_mutex);
760 	ret = nvme_auth_dhchap_setup_host_response(ctrl, chap);
761 	if (ret) {
762 		mutex_unlock(&ctrl->dhchap_auth_mutex);
763 		chap->error = ret;
764 		goto fail2;
765 	}
766 	mutex_unlock(&ctrl->dhchap_auth_mutex);
767 
768 	/* DH-HMAC-CHAP Step 3: send reply */
769 	dev_dbg(ctrl->device, "%s: qid %d send reply\n",
770 		__func__, chap->qid);
771 	ret = nvme_auth_set_dhchap_reply_data(ctrl, chap);
772 	if (ret < 0) {
773 		chap->error = ret;
774 		goto fail2;
775 	}
776 
777 	tl = ret;
778 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
779 	if (ret) {
780 		chap->error = ret;
781 		goto fail2;
782 	}
783 
784 	/* DH-HMAC-CHAP Step 4: receive success1 */
785 	dev_dbg(ctrl->device, "%s: qid %d receive success1\n",
786 		__func__, chap->qid);
787 
788 	memset(chap->buf, 0, CHAP_BUF_SIZE);
789 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, CHAP_BUF_SIZE,
790 			       false);
791 	if (ret) {
792 		dev_warn(ctrl->device,
793 			 "qid %d failed to receive success1, %s %d\n",
794 			 chap->qid, ret < 0 ? "error" : "nvme status", ret);
795 		chap->error = ret;
796 		return;
797 	}
798 	ret = nvme_auth_receive_validate(ctrl, chap->qid,
799 					 chap->buf, chap->transaction,
800 					 NVME_AUTH_DHCHAP_MESSAGE_SUCCESS1);
801 	if (ret) {
802 		chap->status = ret;
803 		chap->error = -ECONNREFUSED;
804 		return;
805 	}
806 
807 	mutex_lock(&ctrl->dhchap_auth_mutex);
808 	if (ctrl->ctrl_key) {
809 		dev_dbg(ctrl->device,
810 			"%s: qid %d controller response\n",
811 			__func__, chap->qid);
812 		ret = nvme_auth_dhchap_setup_ctrl_response(ctrl, chap);
813 		if (ret) {
814 			mutex_unlock(&ctrl->dhchap_auth_mutex);
815 			chap->error = ret;
816 			goto fail2;
817 		}
818 	}
819 	mutex_unlock(&ctrl->dhchap_auth_mutex);
820 
821 	ret = nvme_auth_process_dhchap_success1(ctrl, chap);
822 	if (ret) {
823 		/* Controller authentication failed */
824 		chap->error = -ECONNREFUSED;
825 		goto fail2;
826 	}
827 
828 	if (chap->ctrl_key) {
829 		/* DH-HMAC-CHAP Step 5: send success2 */
830 		dev_dbg(ctrl->device, "%s: qid %d send success2\n",
831 			__func__, chap->qid);
832 		tl = nvme_auth_set_dhchap_success2_data(ctrl, chap);
833 		ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
834 		if (ret)
835 			chap->error = ret;
836 	}
837 	if (!ret) {
838 		chap->error = 0;
839 		return;
840 	}
841 
842 fail2:
843 	dev_dbg(ctrl->device, "%s: qid %d send failure2, status %x\n",
844 		__func__, chap->qid, chap->status);
845 	tl = nvme_auth_set_dhchap_failure2_data(ctrl, chap);
846 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
847 	/*
848 	 * only update error if send failure2 failed and no other
849 	 * error had been set during authentication.
850 	 */
851 	if (ret && !chap->error)
852 		chap->error = ret;
853 }
854 
855 int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid)
856 {
857 	struct nvme_dhchap_queue_context *chap;
858 
859 	if (!ctrl->host_key) {
860 		dev_warn(ctrl->device, "qid %d: no key\n", qid);
861 		return -ENOKEY;
862 	}
863 
864 	if (ctrl->opts->dhchap_ctrl_secret && !ctrl->ctrl_key) {
865 		dev_warn(ctrl->device, "qid %d: invalid ctrl key\n", qid);
866 		return -ENOKEY;
867 	}
868 
869 	chap = &ctrl->dhchap_ctxs[qid];
870 	cancel_work_sync(&chap->auth_work);
871 	queue_work(nvme_auth_wq, &chap->auth_work);
872 	return 0;
873 }
874 EXPORT_SYMBOL_GPL(nvme_auth_negotiate);
875 
876 int nvme_auth_wait(struct nvme_ctrl *ctrl, int qid)
877 {
878 	struct nvme_dhchap_queue_context *chap;
879 	int ret;
880 
881 	chap = &ctrl->dhchap_ctxs[qid];
882 	flush_work(&chap->auth_work);
883 	ret = chap->error;
884 	/* clear sensitive info */
885 	nvme_auth_reset_dhchap(chap);
886 	return ret;
887 }
888 EXPORT_SYMBOL_GPL(nvme_auth_wait);
889 
890 static void nvme_ctrl_auth_work(struct work_struct *work)
891 {
892 	struct nvme_ctrl *ctrl =
893 		container_of(work, struct nvme_ctrl, dhchap_auth_work);
894 	int ret, q;
895 
896 	/*
897 	 * If the ctrl is no connected, bail as reconnect will handle
898 	 * authentication.
899 	 */
900 	if (ctrl->state != NVME_CTRL_LIVE)
901 		return;
902 
903 	/* Authenticate admin queue first */
904 	ret = nvme_auth_negotiate(ctrl, 0);
905 	if (ret) {
906 		dev_warn(ctrl->device,
907 			 "qid 0: error %d setting up authentication\n", ret);
908 		return;
909 	}
910 	ret = nvme_auth_wait(ctrl, 0);
911 	if (ret) {
912 		dev_warn(ctrl->device,
913 			 "qid 0: authentication failed\n");
914 		return;
915 	}
916 
917 	for (q = 1; q < ctrl->queue_count; q++) {
918 		ret = nvme_auth_negotiate(ctrl, q);
919 		if (ret) {
920 			dev_warn(ctrl->device,
921 				 "qid %d: error %d setting up authentication\n",
922 				 q, ret);
923 			break;
924 		}
925 	}
926 
927 	/*
928 	 * Failure is a soft-state; credentials remain valid until
929 	 * the controller terminates the connection.
930 	 */
931 	for (q = 1; q < ctrl->queue_count; q++) {
932 		ret = nvme_auth_wait(ctrl, q);
933 		if (ret)
934 			dev_warn(ctrl->device,
935 				 "qid %d: authentication failed\n", q);
936 	}
937 }
938 
939 int nvme_auth_init_ctrl(struct nvme_ctrl *ctrl)
940 {
941 	struct nvme_dhchap_queue_context *chap;
942 	int i, ret;
943 
944 	mutex_init(&ctrl->dhchap_auth_mutex);
945 	INIT_WORK(&ctrl->dhchap_auth_work, nvme_ctrl_auth_work);
946 	if (!ctrl->opts)
947 		return 0;
948 	ret = nvme_auth_generate_key(ctrl->opts->dhchap_secret,
949 			&ctrl->host_key);
950 	if (ret)
951 		return ret;
952 	ret = nvme_auth_generate_key(ctrl->opts->dhchap_ctrl_secret,
953 			&ctrl->ctrl_key);
954 	if (ret)
955 		goto err_free_dhchap_secret;
956 
957 	if (!ctrl->opts->dhchap_secret && !ctrl->opts->dhchap_ctrl_secret)
958 		return 0;
959 
960 	ctrl->dhchap_ctxs = kvcalloc(ctrl_max_dhchaps(ctrl),
961 				sizeof(*chap), GFP_KERNEL);
962 	if (!ctrl->dhchap_ctxs) {
963 		ret = -ENOMEM;
964 		goto err_free_dhchap_ctrl_secret;
965 	}
966 
967 	for (i = 0; i < ctrl_max_dhchaps(ctrl); i++) {
968 		chap = &ctrl->dhchap_ctxs[i];
969 		chap->qid = i;
970 		chap->ctrl = ctrl;
971 		INIT_WORK(&chap->auth_work, nvme_queue_auth_work);
972 	}
973 
974 	return 0;
975 err_free_dhchap_ctrl_secret:
976 	nvme_auth_free_key(ctrl->ctrl_key);
977 	ctrl->ctrl_key = NULL;
978 err_free_dhchap_secret:
979 	nvme_auth_free_key(ctrl->host_key);
980 	ctrl->host_key = NULL;
981 	return ret;
982 }
983 EXPORT_SYMBOL_GPL(nvme_auth_init_ctrl);
984 
985 void nvme_auth_stop(struct nvme_ctrl *ctrl)
986 {
987 	cancel_work_sync(&ctrl->dhchap_auth_work);
988 }
989 EXPORT_SYMBOL_GPL(nvme_auth_stop);
990 
991 void nvme_auth_free(struct nvme_ctrl *ctrl)
992 {
993 	int i;
994 
995 	if (ctrl->dhchap_ctxs) {
996 		for (i = 0; i < ctrl_max_dhchaps(ctrl); i++)
997 			nvme_auth_free_dhchap(&ctrl->dhchap_ctxs[i]);
998 		kfree(ctrl->dhchap_ctxs);
999 	}
1000 	if (ctrl->host_key) {
1001 		nvme_auth_free_key(ctrl->host_key);
1002 		ctrl->host_key = NULL;
1003 	}
1004 	if (ctrl->ctrl_key) {
1005 		nvme_auth_free_key(ctrl->ctrl_key);
1006 		ctrl->ctrl_key = NULL;
1007 	}
1008 }
1009 EXPORT_SYMBOL_GPL(nvme_auth_free);
1010 
1011 int __init nvme_init_auth(void)
1012 {
1013 	nvme_auth_wq = alloc_workqueue("nvme-auth-wq",
1014 			       WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 0);
1015 	if (!nvme_auth_wq)
1016 		return -ENOMEM;
1017 
1018 	nvme_chap_buf_cache = kmem_cache_create("nvme-chap-buf-cache",
1019 				CHAP_BUF_SIZE, 0, SLAB_HWCACHE_ALIGN, NULL);
1020 	if (!nvme_chap_buf_cache)
1021 		goto err_destroy_workqueue;
1022 
1023 	nvme_chap_buf_pool = mempool_create(16, mempool_alloc_slab,
1024 			mempool_free_slab, nvme_chap_buf_cache);
1025 	if (!nvme_chap_buf_pool)
1026 		goto err_destroy_chap_buf_cache;
1027 
1028 	return 0;
1029 err_destroy_chap_buf_cache:
1030 	kmem_cache_destroy(nvme_chap_buf_cache);
1031 err_destroy_workqueue:
1032 	destroy_workqueue(nvme_auth_wq);
1033 	return -ENOMEM;
1034 }
1035 
1036 void __exit nvme_exit_auth(void)
1037 {
1038 	mempool_destroy(nvme_chap_buf_pool);
1039 	kmem_cache_destroy(nvme_chap_buf_cache);
1040 	destroy_workqueue(nvme_auth_wq);
1041 }
1042