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