1// SPDX-License-Identifier: GPL-2.0
2/*
3 * NVMe over Fabrics DH-HMAC-CHAP authentication command handling.
4 * Copyright (c) 2020 Hannes Reinecke, SUSE Software Solutions.
5 * All rights reserved.
6 */
7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8#include <linux/blkdev.h>
9#include <linux/random.h>
10#include <linux/nvme-auth.h>
11#include <crypto/hash.h>
12#include <crypto/kpp.h>
13#include "nvmet.h"
14
15static void nvmet_auth_expired_work(struct work_struct *work)
16{
17	struct nvmet_sq *sq = container_of(to_delayed_work(work),
18			struct nvmet_sq, auth_expired_work);
19
20	pr_debug("%s: ctrl %d qid %d transaction %u expired, resetting\n",
21		 __func__, sq->ctrl->cntlid, sq->qid, sq->dhchap_tid);
22	sq->dhchap_step = NVME_AUTH_DHCHAP_MESSAGE_NEGOTIATE;
23	sq->dhchap_tid = -1;
24}
25
26void nvmet_auth_sq_init(struct nvmet_sq *sq)
27{
28	/* Initialize in-band authentication */
29	INIT_DELAYED_WORK(&sq->auth_expired_work, nvmet_auth_expired_work);
30	sq->authenticated = false;
31	sq->dhchap_step = NVME_AUTH_DHCHAP_MESSAGE_NEGOTIATE;
32}
33
34static u16 nvmet_auth_negotiate(struct nvmet_req *req, void *d)
35{
36	struct nvmet_ctrl *ctrl = req->sq->ctrl;
37	struct nvmf_auth_dhchap_negotiate_data *data = d;
38	int i, hash_id = 0, fallback_hash_id = 0, dhgid, fallback_dhgid;
39
40	pr_debug("%s: ctrl %d qid %d: data sc_d %d napd %d authid %d halen %d dhlen %d\n",
41		 __func__, ctrl->cntlid, req->sq->qid,
42		 data->sc_c, data->napd, data->auth_protocol[0].dhchap.authid,
43		 data->auth_protocol[0].dhchap.halen,
44		 data->auth_protocol[0].dhchap.dhlen);
45	req->sq->dhchap_tid = le16_to_cpu(data->t_id);
46	if (data->sc_c)
47		return NVME_AUTH_DHCHAP_FAILURE_CONCAT_MISMATCH;
48
49	if (data->napd != 1)
50		return NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
51
52	if (data->auth_protocol[0].dhchap.authid !=
53	    NVME_AUTH_DHCHAP_AUTH_ID)
54		return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
55
56	for (i = 0; i < data->auth_protocol[0].dhchap.halen; i++) {
57		u8 host_hmac_id = data->auth_protocol[0].dhchap.idlist[i];
58
59		if (!fallback_hash_id &&
60		    crypto_has_shash(nvme_auth_hmac_name(host_hmac_id), 0, 0))
61			fallback_hash_id = host_hmac_id;
62		if (ctrl->shash_id != host_hmac_id)
63			continue;
64		hash_id = ctrl->shash_id;
65		break;
66	}
67	if (hash_id == 0) {
68		if (fallback_hash_id == 0) {
69			pr_debug("%s: ctrl %d qid %d: no usable hash found\n",
70				 __func__, ctrl->cntlid, req->sq->qid);
71			return NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
72		}
73		pr_debug("%s: ctrl %d qid %d: no usable hash found, falling back to %s\n",
74			 __func__, ctrl->cntlid, req->sq->qid,
75			 nvme_auth_hmac_name(fallback_hash_id));
76		ctrl->shash_id = fallback_hash_id;
77	}
78
79	dhgid = -1;
80	fallback_dhgid = -1;
81	for (i = 0; i < data->auth_protocol[0].dhchap.dhlen; i++) {
82		int tmp_dhgid = data->auth_protocol[0].dhchap.idlist[i + 30];
83
84		if (tmp_dhgid != ctrl->dh_gid) {
85			dhgid = tmp_dhgid;
86			break;
87		}
88		if (fallback_dhgid < 0) {
89			const char *kpp = nvme_auth_dhgroup_kpp(tmp_dhgid);
90
91			if (crypto_has_kpp(kpp, 0, 0))
92				fallback_dhgid = tmp_dhgid;
93		}
94	}
95	if (dhgid < 0) {
96		if (fallback_dhgid < 0) {
97			pr_debug("%s: ctrl %d qid %d: no usable DH group found\n",
98				 __func__, ctrl->cntlid, req->sq->qid);
99			return NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
100		}
101		pr_debug("%s: ctrl %d qid %d: configured DH group %s not found\n",
102			 __func__, ctrl->cntlid, req->sq->qid,
103			 nvme_auth_dhgroup_name(fallback_dhgid));
104		ctrl->dh_gid = fallback_dhgid;
105	}
106	pr_debug("%s: ctrl %d qid %d: selected DH group %s (%d)\n",
107		 __func__, ctrl->cntlid, req->sq->qid,
108		 nvme_auth_dhgroup_name(ctrl->dh_gid), ctrl->dh_gid);
109	return 0;
110}
111
112static u16 nvmet_auth_reply(struct nvmet_req *req, void *d)
113{
114	struct nvmet_ctrl *ctrl = req->sq->ctrl;
115	struct nvmf_auth_dhchap_reply_data *data = d;
116	u16 dhvlen = le16_to_cpu(data->dhvlen);
117	u8 *response;
118
119	pr_debug("%s: ctrl %d qid %d: data hl %d cvalid %d dhvlen %u\n",
120		 __func__, ctrl->cntlid, req->sq->qid,
121		 data->hl, data->cvalid, dhvlen);
122
123	if (dhvlen) {
124		if (!ctrl->dh_tfm)
125			return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
126		if (nvmet_auth_ctrl_sesskey(req, data->rval + 2 * data->hl,
127					    dhvlen) < 0)
128			return NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
129	}
130
131	response = kmalloc(data->hl, GFP_KERNEL);
132	if (!response)
133		return NVME_AUTH_DHCHAP_FAILURE_FAILED;
134
135	if (!ctrl->host_key) {
136		pr_warn("ctrl %d qid %d no host key\n",
137			ctrl->cntlid, req->sq->qid);
138		kfree(response);
139		return NVME_AUTH_DHCHAP_FAILURE_FAILED;
140	}
141	if (nvmet_auth_host_hash(req, response, data->hl) < 0) {
142		pr_debug("ctrl %d qid %d host hash failed\n",
143			 ctrl->cntlid, req->sq->qid);
144		kfree(response);
145		return NVME_AUTH_DHCHAP_FAILURE_FAILED;
146	}
147
148	if (memcmp(data->rval, response, data->hl)) {
149		pr_info("ctrl %d qid %d host response mismatch\n",
150			ctrl->cntlid, req->sq->qid);
151		kfree(response);
152		return NVME_AUTH_DHCHAP_FAILURE_FAILED;
153	}
154	kfree(response);
155	pr_debug("%s: ctrl %d qid %d host authenticated\n",
156		 __func__, ctrl->cntlid, req->sq->qid);
157	if (data->cvalid) {
158		req->sq->dhchap_c2 = kmemdup(data->rval + data->hl, data->hl,
159					     GFP_KERNEL);
160		if (!req->sq->dhchap_c2)
161			return NVME_AUTH_DHCHAP_FAILURE_FAILED;
162
163		pr_debug("%s: ctrl %d qid %d challenge %*ph\n",
164			 __func__, ctrl->cntlid, req->sq->qid, data->hl,
165			 req->sq->dhchap_c2);
166	} else {
167		req->sq->authenticated = true;
168		req->sq->dhchap_c2 = NULL;
169	}
170	req->sq->dhchap_s2 = le32_to_cpu(data->seqnum);
171
172	return 0;
173}
174
175static u16 nvmet_auth_failure2(void *d)
176{
177	struct nvmf_auth_dhchap_failure_data *data = d;
178
179	return data->rescode_exp;
180}
181
182void nvmet_execute_auth_send(struct nvmet_req *req)
183{
184	struct nvmet_ctrl *ctrl = req->sq->ctrl;
185	struct nvmf_auth_dhchap_success2_data *data;
186	void *d;
187	u32 tl;
188	u16 status = 0;
189
190	if (req->cmd->auth_send.secp != NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER) {
191		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
192		req->error_loc =
193			offsetof(struct nvmf_auth_send_command, secp);
194		goto done;
195	}
196	if (req->cmd->auth_send.spsp0 != 0x01) {
197		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
198		req->error_loc =
199			offsetof(struct nvmf_auth_send_command, spsp0);
200		goto done;
201	}
202	if (req->cmd->auth_send.spsp1 != 0x01) {
203		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
204		req->error_loc =
205			offsetof(struct nvmf_auth_send_command, spsp1);
206		goto done;
207	}
208	tl = le32_to_cpu(req->cmd->auth_send.tl);
209	if (!tl) {
210		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
211		req->error_loc =
212			offsetof(struct nvmf_auth_send_command, tl);
213		goto done;
214	}
215	if (!nvmet_check_transfer_len(req, tl)) {
216		pr_debug("%s: transfer length mismatch (%u)\n", __func__, tl);
217		return;
218	}
219
220	d = kmalloc(tl, GFP_KERNEL);
221	if (!d) {
222		status = NVME_SC_INTERNAL;
223		goto done;
224	}
225
226	status = nvmet_copy_from_sgl(req, 0, d, tl);
227	if (status)
228		goto done_kfree;
229
230	data = d;
231	pr_debug("%s: ctrl %d qid %d type %d id %d step %x\n", __func__,
232		 ctrl->cntlid, req->sq->qid, data->auth_type, data->auth_id,
233		 req->sq->dhchap_step);
234	if (data->auth_type != NVME_AUTH_COMMON_MESSAGES &&
235	    data->auth_type != NVME_AUTH_DHCHAP_MESSAGES)
236		goto done_failure1;
237	if (data->auth_type == NVME_AUTH_COMMON_MESSAGES) {
238		if (data->auth_id == NVME_AUTH_DHCHAP_MESSAGE_NEGOTIATE) {
239			/* Restart negotiation */
240			pr_debug("%s: ctrl %d qid %d reset negotiation\n", __func__,
241				 ctrl->cntlid, req->sq->qid);
242			if (!req->sq->qid) {
243				if (nvmet_setup_auth(ctrl) < 0) {
244					status = NVME_SC_INTERNAL;
245					pr_err("ctrl %d qid 0 failed to setup"
246					       "re-authentication",
247					       ctrl->cntlid);
248					goto done_failure1;
249				}
250			}
251			req->sq->dhchap_step = NVME_AUTH_DHCHAP_MESSAGE_NEGOTIATE;
252		} else if (data->auth_id != req->sq->dhchap_step)
253			goto done_failure1;
254		/* Validate negotiation parameters */
255		status = nvmet_auth_negotiate(req, d);
256		if (status == 0)
257			req->sq->dhchap_step =
258				NVME_AUTH_DHCHAP_MESSAGE_CHALLENGE;
259		else {
260			req->sq->dhchap_step =
261				NVME_AUTH_DHCHAP_MESSAGE_FAILURE1;
262			req->sq->dhchap_status = status;
263			status = 0;
264		}
265		goto done_kfree;
266	}
267	if (data->auth_id != req->sq->dhchap_step) {
268		pr_debug("%s: ctrl %d qid %d step mismatch (%d != %d)\n",
269			 __func__, ctrl->cntlid, req->sq->qid,
270			 data->auth_id, req->sq->dhchap_step);
271		goto done_failure1;
272	}
273	if (le16_to_cpu(data->t_id) != req->sq->dhchap_tid) {
274		pr_debug("%s: ctrl %d qid %d invalid transaction %d (expected %d)\n",
275			 __func__, ctrl->cntlid, req->sq->qid,
276			 le16_to_cpu(data->t_id),
277			 req->sq->dhchap_tid);
278		req->sq->dhchap_step =
279			NVME_AUTH_DHCHAP_MESSAGE_FAILURE1;
280		req->sq->dhchap_status =
281			NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
282		goto done_kfree;
283	}
284
285	switch (data->auth_id) {
286	case NVME_AUTH_DHCHAP_MESSAGE_REPLY:
287		status = nvmet_auth_reply(req, d);
288		if (status == 0)
289			req->sq->dhchap_step =
290				NVME_AUTH_DHCHAP_MESSAGE_SUCCESS1;
291		else {
292			req->sq->dhchap_step =
293				NVME_AUTH_DHCHAP_MESSAGE_FAILURE1;
294			req->sq->dhchap_status = status;
295			status = 0;
296		}
297		goto done_kfree;
298	case NVME_AUTH_DHCHAP_MESSAGE_SUCCESS2:
299		req->sq->authenticated = true;
300		pr_debug("%s: ctrl %d qid %d ctrl authenticated\n",
301			 __func__, ctrl->cntlid, req->sq->qid);
302		goto done_kfree;
303	case NVME_AUTH_DHCHAP_MESSAGE_FAILURE2:
304		status = nvmet_auth_failure2(d);
305		if (status) {
306			pr_warn("ctrl %d qid %d: authentication failed (%d)\n",
307				ctrl->cntlid, req->sq->qid, status);
308			req->sq->dhchap_status = status;
309			req->sq->authenticated = false;
310			status = 0;
311		}
312		goto done_kfree;
313	default:
314		req->sq->dhchap_status =
315			NVME_AUTH_DHCHAP_FAILURE_INCORRECT_MESSAGE;
316		req->sq->dhchap_step =
317			NVME_AUTH_DHCHAP_MESSAGE_FAILURE2;
318		req->sq->authenticated = false;
319		goto done_kfree;
320	}
321done_failure1:
322	req->sq->dhchap_status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_MESSAGE;
323	req->sq->dhchap_step = NVME_AUTH_DHCHAP_MESSAGE_FAILURE2;
324
325done_kfree:
326	kfree(d);
327done:
328	pr_debug("%s: ctrl %d qid %d dhchap status %x step %x\n", __func__,
329		 ctrl->cntlid, req->sq->qid,
330		 req->sq->dhchap_status, req->sq->dhchap_step);
331	if (status)
332		pr_debug("%s: ctrl %d qid %d nvme status %x error loc %d\n",
333			 __func__, ctrl->cntlid, req->sq->qid,
334			 status, req->error_loc);
335	req->cqe->result.u64 = 0;
336	if (req->sq->dhchap_step != NVME_AUTH_DHCHAP_MESSAGE_SUCCESS2 &&
337	    req->sq->dhchap_step != NVME_AUTH_DHCHAP_MESSAGE_FAILURE2) {
338		unsigned long auth_expire_secs = ctrl->kato ? ctrl->kato : 120;
339
340		mod_delayed_work(system_wq, &req->sq->auth_expired_work,
341				 auth_expire_secs * HZ);
342		goto complete;
343	}
344	/* Final states, clear up variables */
345	nvmet_auth_sq_free(req->sq);
346	if (req->sq->dhchap_step == NVME_AUTH_DHCHAP_MESSAGE_FAILURE2)
347		nvmet_ctrl_fatal_error(ctrl);
348
349complete:
350	nvmet_req_complete(req, status);
351}
352
353static int nvmet_auth_challenge(struct nvmet_req *req, void *d, int al)
354{
355	struct nvmf_auth_dhchap_challenge_data *data = d;
356	struct nvmet_ctrl *ctrl = req->sq->ctrl;
357	int ret = 0;
358	int hash_len = nvme_auth_hmac_hash_len(ctrl->shash_id);
359	int data_size = sizeof(*d) + hash_len;
360
361	if (ctrl->dh_tfm)
362		data_size += ctrl->dh_keysize;
363	if (al < data_size) {
364		pr_debug("%s: buffer too small (al %d need %d)\n", __func__,
365			 al, data_size);
366		return -EINVAL;
367	}
368	memset(data, 0, data_size);
369	req->sq->dhchap_s1 = nvme_auth_get_seqnum();
370	data->auth_type = NVME_AUTH_DHCHAP_MESSAGES;
371	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_CHALLENGE;
372	data->t_id = cpu_to_le16(req->sq->dhchap_tid);
373	data->hashid = ctrl->shash_id;
374	data->hl = hash_len;
375	data->seqnum = cpu_to_le32(req->sq->dhchap_s1);
376	req->sq->dhchap_c1 = kmalloc(data->hl, GFP_KERNEL);
377	if (!req->sq->dhchap_c1)
378		return -ENOMEM;
379	get_random_bytes(req->sq->dhchap_c1, data->hl);
380	memcpy(data->cval, req->sq->dhchap_c1, data->hl);
381	if (ctrl->dh_tfm) {
382		data->dhgid = ctrl->dh_gid;
383		data->dhvlen = cpu_to_le16(ctrl->dh_keysize);
384		ret = nvmet_auth_ctrl_exponential(req, data->cval + data->hl,
385						  ctrl->dh_keysize);
386	}
387	pr_debug("%s: ctrl %d qid %d seq %d transaction %d hl %d dhvlen %zu\n",
388		 __func__, ctrl->cntlid, req->sq->qid, req->sq->dhchap_s1,
389		 req->sq->dhchap_tid, data->hl, ctrl->dh_keysize);
390	return ret;
391}
392
393static int nvmet_auth_success1(struct nvmet_req *req, void *d, int al)
394{
395	struct nvmf_auth_dhchap_success1_data *data = d;
396	struct nvmet_ctrl *ctrl = req->sq->ctrl;
397	int hash_len = nvme_auth_hmac_hash_len(ctrl->shash_id);
398
399	WARN_ON(al < sizeof(*data));
400	memset(data, 0, sizeof(*data));
401	data->auth_type = NVME_AUTH_DHCHAP_MESSAGES;
402	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_SUCCESS1;
403	data->t_id = cpu_to_le16(req->sq->dhchap_tid);
404	data->hl = hash_len;
405	if (req->sq->dhchap_c2) {
406		if (!ctrl->ctrl_key) {
407			pr_warn("ctrl %d qid %d no ctrl key\n",
408				ctrl->cntlid, req->sq->qid);
409			return NVME_AUTH_DHCHAP_FAILURE_FAILED;
410		}
411		if (nvmet_auth_ctrl_hash(req, data->rval, data->hl))
412			return NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
413		data->rvalid = 1;
414		pr_debug("ctrl %d qid %d response %*ph\n",
415			 ctrl->cntlid, req->sq->qid, data->hl, data->rval);
416	}
417	return 0;
418}
419
420static void nvmet_auth_failure1(struct nvmet_req *req, void *d, int al)
421{
422	struct nvmf_auth_dhchap_failure_data *data = d;
423
424	WARN_ON(al < sizeof(*data));
425	data->auth_type = NVME_AUTH_COMMON_MESSAGES;
426	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_FAILURE1;
427	data->t_id = cpu_to_le16(req->sq->dhchap_tid);
428	data->rescode = NVME_AUTH_DHCHAP_FAILURE_REASON_FAILED;
429	data->rescode_exp = req->sq->dhchap_status;
430}
431
432void nvmet_execute_auth_receive(struct nvmet_req *req)
433{
434	struct nvmet_ctrl *ctrl = req->sq->ctrl;
435	void *d;
436	u32 al;
437	u16 status = 0;
438
439	if (req->cmd->auth_receive.secp != NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER) {
440		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
441		req->error_loc =
442			offsetof(struct nvmf_auth_receive_command, secp);
443		goto done;
444	}
445	if (req->cmd->auth_receive.spsp0 != 0x01) {
446		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
447		req->error_loc =
448			offsetof(struct nvmf_auth_receive_command, spsp0);
449		goto done;
450	}
451	if (req->cmd->auth_receive.spsp1 != 0x01) {
452		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
453		req->error_loc =
454			offsetof(struct nvmf_auth_receive_command, spsp1);
455		goto done;
456	}
457	al = le32_to_cpu(req->cmd->auth_receive.al);
458	if (!al) {
459		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
460		req->error_loc =
461			offsetof(struct nvmf_auth_receive_command, al);
462		goto done;
463	}
464	if (!nvmet_check_transfer_len(req, al)) {
465		pr_debug("%s: transfer length mismatch (%u)\n", __func__, al);
466		return;
467	}
468
469	d = kmalloc(al, GFP_KERNEL);
470	if (!d) {
471		status = NVME_SC_INTERNAL;
472		goto done;
473	}
474	pr_debug("%s: ctrl %d qid %d step %x\n", __func__,
475		 ctrl->cntlid, req->sq->qid, req->sq->dhchap_step);
476	switch (req->sq->dhchap_step) {
477	case NVME_AUTH_DHCHAP_MESSAGE_CHALLENGE:
478		if (nvmet_auth_challenge(req, d, al) < 0) {
479			pr_warn("ctrl %d qid %d: challenge error (%d)\n",
480				ctrl->cntlid, req->sq->qid, status);
481			status = NVME_SC_INTERNAL;
482			break;
483		}
484		req->sq->dhchap_step = NVME_AUTH_DHCHAP_MESSAGE_REPLY;
485		break;
486	case NVME_AUTH_DHCHAP_MESSAGE_SUCCESS1:
487		status = nvmet_auth_success1(req, d, al);
488		if (status) {
489			req->sq->dhchap_status = status;
490			req->sq->authenticated = false;
491			nvmet_auth_failure1(req, d, al);
492			pr_warn("ctrl %d qid %d: success1 status (%x)\n",
493				ctrl->cntlid, req->sq->qid,
494				req->sq->dhchap_status);
495			break;
496		}
497		req->sq->dhchap_step = NVME_AUTH_DHCHAP_MESSAGE_SUCCESS2;
498		break;
499	case NVME_AUTH_DHCHAP_MESSAGE_FAILURE1:
500		req->sq->authenticated = false;
501		nvmet_auth_failure1(req, d, al);
502		pr_warn("ctrl %d qid %d failure1 (%x)\n",
503			ctrl->cntlid, req->sq->qid, req->sq->dhchap_status);
504		break;
505	default:
506		pr_warn("ctrl %d qid %d unhandled step (%d)\n",
507			ctrl->cntlid, req->sq->qid, req->sq->dhchap_step);
508		req->sq->dhchap_step = NVME_AUTH_DHCHAP_MESSAGE_FAILURE1;
509		req->sq->dhchap_status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
510		nvmet_auth_failure1(req, d, al);
511		status = 0;
512		break;
513	}
514
515	status = nvmet_copy_to_sgl(req, 0, d, al);
516	kfree(d);
517done:
518	req->cqe->result.u64 = 0;
519
520	if (req->sq->dhchap_step == NVME_AUTH_DHCHAP_MESSAGE_SUCCESS2)
521		nvmet_auth_sq_free(req->sq);
522	else if (req->sq->dhchap_step == NVME_AUTH_DHCHAP_MESSAGE_FAILURE1) {
523		nvmet_auth_sq_free(req->sq);
524		nvmet_ctrl_fatal_error(ctrl);
525	}
526	nvmet_req_complete(req, status);
527}
528