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Merge tag 'mfd-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd
[linux-block.git] / arch / s390 / kernel / cert_store.c
CommitLineData
8cf57d72
AE		 1// SPDX-License-Identifier: GPL-2.0
2/*
3 * DIAG 0x320 support and certificate store handling
4 *
5 * Copyright IBM Corp. 2023
6 * Author(s): Anastasia Eskova <anastasia.eskova@ibm.com>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/delay.h>
12#include <linux/device.h>
13#include <linux/fs.h>
14#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/key-type.h>
17#include <linux/key.h>
18#include <linux/keyctl.h>
19#include <linux/kobject.h>
20#include <linux/module.h>
21#include <linux/seq_file.h>
22#include <linux/slab.h>
23#include <linux/sysfs.h>
24#include <crypto/sha2.h>
25#include <keys/user-type.h>
26#include <asm/debug.h>
27#include <asm/diag.h>
28#include <asm/ebcdic.h>
29#include <asm/sclp.h>
30
31#define DIAG_MAX_RETRIES 10
32
33#define VCE_FLAGS_VALID_MASK 0x80
34
35#define ISM_LEN_DWORDS 4
36#define VCSSB_LEN_BYTES 128
37#define VCSSB_LEN_NO_CERTS 4
38#define VCB_LEN_NO_CERTS 64
39#define VC_NAME_LEN_BYTES 64
40
41#define CERT_STORE_KEY_TYPE_NAME "cert_store_key"
42#define CERT_STORE_KEYRING_NAME "cert_store"
43
44static debug_info_t *cert_store_dbf;
45static debug_info_t *cert_store_hexdump;
46
47#define pr_dbf_msg(fmt, ...) \
48 debug_sprintf_event(cert_store_dbf, 3, fmt "\n", ## __VA_ARGS__)
49
50enum diag320_subcode {
51 DIAG320_SUBCODES = 0,
52 DIAG320_STORAGE = 1,
53 DIAG320_CERT_BLOCK = 2,
54};
55
56enum diag320_rc {
57 DIAG320_RC_OK = 0x0001,
58 DIAG320_RC_CS_NOMATCH = 0x0306,
59};
60
61/* Verification Certificates Store Support Block (VCSSB). */
62struct vcssb {
63 u32 vcssb_length;
64 u8 pad_0x04[3];
65 u8 version;
66 u8 pad_0x08[8];
67 u32 cs_token;
68 u8 pad_0x14[12];
69 u16 total_vc_index_count;
70 u16 max_vc_index_count;
71 u8 pad_0x24[28];
72 u32 max_vce_length;
73 u32 max_vcxe_length;
74 u8 pad_0x48[8];
75 u32 max_single_vcb_length;
76 u32 total_vcb_length;
77 u32 max_single_vcxb_length;
78 u32 total_vcxb_length;
79 u8 pad_0x60[32];
80} __packed __aligned(8);
81
82/* Verification Certificate Entry (VCE) Header. */
83struct vce_header {
84 u32 vce_length;
85 u8 flags;
86 u8 key_type;
87 u16 vc_index;
88 u8 vc_name[VC_NAME_LEN_BYTES]; /* EBCDIC */
89 u8 vc_format;
90 u8 pad_0x49;
91 u16 key_id_length;
92 u8 pad_0x4c;
93 u8 vc_hash_type;
94 u16 vc_hash_length;
95 u8 pad_0x50[4];
96 u32 vc_length;
97 u8 pad_0x58[8];
98 u16 vc_hash_offset;
99 u16 vc_offset;
100 u8 pad_0x64[28];
101} __packed __aligned(4);
102
103/* Verification Certificate Block (VCB) Header. */
104struct vcb_header {
105 u32 vcb_input_length;
106 u8 pad_0x04[4];
107 u16 first_vc_index;
108 u16 last_vc_index;
109 u32 pad_0x0c;
110 u32 cs_token;
111 u8 pad_0x14[12];
112 u32 vcb_output_length;
113 u8 pad_0x24[3];
114 u8 version;
115 u16 stored_vc_count;
116 u16 remaining_vc_count;
117 u8 pad_0x2c[20];
118} __packed __aligned(4);
119
120/* Verification Certificate Block (VCB). */
121struct vcb {
122 struct vcb_header vcb_hdr;
123 u8 vcb_buf[];
124} __packed __aligned(4);
125
126/* Verification Certificate Entry (VCE). */
127struct vce {
128 struct vce_header vce_hdr;
129 u8 cert_data_buf[];
130} __packed __aligned(4);
131
132static void cert_store_key_describe(const struct key *key, struct seq_file *m)
133{
134 char ascii[VC_NAME_LEN_BYTES + 1];
135
136 /*
137 * First 64 bytes of the key description is key name in EBCDIC CP 500.
138 * Convert it to ASCII for displaying in /proc/keys.
139 */
140 strscpy(ascii, key->description, sizeof(ascii));
141 EBCASC_500(ascii, VC_NAME_LEN_BYTES);
142 seq_puts(m, ascii);
143
144 seq_puts(m, &key->description[VC_NAME_LEN_BYTES]);
145 if (key_is_positive(key))
146 seq_printf(m, ": %u", key->datalen);
147}
148
149/*
150 * Certificate store key type takes over properties of
151 * user key but cannot be updated.
152 */
153static struct key_type key_type_cert_store_key = {
154 .name = CERT_STORE_KEY_TYPE_NAME,
155 .preparse = user_preparse,
156 .free_preparse = user_free_preparse,
157 .instantiate = generic_key_instantiate,
158 .revoke = user_revoke,
159 .destroy = user_destroy,
160 .describe = cert_store_key_describe,
161 .read = user_read,
162};
163
164/* Logging functions. */
165static void pr_dbf_vcb(const struct vcb *b)
166{
167 pr_dbf_msg("VCB Header:");
168 pr_dbf_msg("vcb_input_length: %d", b->vcb_hdr.vcb_input_length);
169 pr_dbf_msg("first_vc_index: %d", b->vcb_hdr.first_vc_index);
170 pr_dbf_msg("last_vc_index: %d", b->vcb_hdr.last_vc_index);
171 pr_dbf_msg("cs_token: %d", b->vcb_hdr.cs_token);
172 pr_dbf_msg("vcb_output_length: %d", b->vcb_hdr.vcb_output_length);
173 pr_dbf_msg("version: %d", b->vcb_hdr.version);
174 pr_dbf_msg("stored_vc_count: %d", b->vcb_hdr.stored_vc_count);
175 pr_dbf_msg("remaining_vc_count: %d", b->vcb_hdr.remaining_vc_count);
176}
177
178static void pr_dbf_vce(const struct vce *e)
179{
180 unsigned char vc_name[VC_NAME_LEN_BYTES + 1];
181 char log_string[VC_NAME_LEN_BYTES + 40];
182
183 pr_dbf_msg("VCE Header:");
184 pr_dbf_msg("vce_hdr.vce_length: %d", e->vce_hdr.vce_length);
185 pr_dbf_msg("vce_hdr.flags: %d", e->vce_hdr.flags);
186 pr_dbf_msg("vce_hdr.key_type: %d", e->vce_hdr.key_type);
187 pr_dbf_msg("vce_hdr.vc_index: %d", e->vce_hdr.vc_index);
188 pr_dbf_msg("vce_hdr.vc_format: %d", e->vce_hdr.vc_format);
189 pr_dbf_msg("vce_hdr.key_id_length: %d", e->vce_hdr.key_id_length);
190 pr_dbf_msg("vce_hdr.vc_hash_type: %d", e->vce_hdr.vc_hash_type);
191 pr_dbf_msg("vce_hdr.vc_hash_length: %d", e->vce_hdr.vc_hash_length);
192 pr_dbf_msg("vce_hdr.vc_hash_offset: %d", e->vce_hdr.vc_hash_offset);
193 pr_dbf_msg("vce_hdr.vc_length: %d", e->vce_hdr.vc_length);
194 pr_dbf_msg("vce_hdr.vc_offset: %d", e->vce_hdr.vc_offset);
195
196 /* Certificate name in ASCII. */
197 memcpy(vc_name, e->vce_hdr.vc_name, VC_NAME_LEN_BYTES);
198 EBCASC_500(vc_name, VC_NAME_LEN_BYTES);
199 vc_name[VC_NAME_LEN_BYTES] = '\0';
200
201 snprintf(log_string, sizeof(log_string),
202 "index: %d vce_hdr.vc_name (ASCII): %s",
203 e->vce_hdr.vc_index, vc_name);
204 debug_text_event(cert_store_hexdump, 3, log_string);
205
206 /* Certificate data. */
207 debug_text_event(cert_store_hexdump, 3, "VCE: Certificate data start");
208 debug_event(cert_store_hexdump, 3, (u8 *)e->cert_data_buf, 128);
209 debug_text_event(cert_store_hexdump, 3, "VCE: Certificate data end");
210 debug_event(cert_store_hexdump, 3,
211 (u8 *)e->cert_data_buf + e->vce_hdr.vce_length - 128, 128);
212}
213
214static void pr_dbf_vcssb(const struct vcssb *s)
215{
216 debug_text_event(cert_store_hexdump, 3, "DIAG320 Subcode1");
217 debug_event(cert_store_hexdump, 3, (u8 *)s, VCSSB_LEN_BYTES);
218
219 pr_dbf_msg("VCSSB:");
220 pr_dbf_msg("vcssb_length: %u", s->vcssb_length);
221 pr_dbf_msg("version: %u", s->version);
222 pr_dbf_msg("cs_token: %u", s->cs_token);
223 pr_dbf_msg("total_vc_index_count: %u", s->total_vc_index_count);
224 pr_dbf_msg("max_vc_index_count: %u", s->max_vc_index_count);
225 pr_dbf_msg("max_vce_length: %u", s->max_vce_length);
226 pr_dbf_msg("max_vcxe_length: %u", s->max_vce_length);
227 pr_dbf_msg("max_single_vcb_length: %u", s->max_single_vcb_length);
228 pr_dbf_msg("total_vcb_length: %u", s->total_vcb_length);
229 pr_dbf_msg("max_single_vcxb_length: %u", s->max_single_vcxb_length);
230 pr_dbf_msg("total_vcxb_length: %u", s->total_vcxb_length);
231}
232
233static int __diag320(unsigned long subcode, void *addr)
234{
235 union register_pair rp = { .even = (unsigned long)addr, };
236
237 asm volatile(
238 " diag %[rp],%[subcode],0x320\n"
239 "0: nopr %%r7\n"
240 EX_TABLE(0b, 0b)
241 : [rp] "+d" (rp.pair)
242 : [subcode] "d" (subcode)
243 : "cc", "memory");
244
245 return rp.odd;
246}
247
248static int diag320(unsigned long subcode, void *addr)
249{
250 diag_stat_inc(DIAG_STAT_X320);
251
252 return __diag320(subcode, addr);
253}
254
255/*
256 * Calculate SHA256 hash of the VCE certificate and compare it to hash stored in
257 * VCE. Return -EINVAL if hashes don't match.
258 */
259static int check_certificate_hash(const struct vce *vce)
260{
261 u8 hash[SHA256_DIGEST_SIZE];
262 u16 vc_hash_length;
263 u8 *vce_hash;
264
265 vce_hash = (u8 *)vce + vce->vce_hdr.vc_hash_offset;
266 vc_hash_length = vce->vce_hdr.vc_hash_length;
267 sha256((u8 *)vce + vce->vce_hdr.vc_offset, vce->vce_hdr.vc_length, hash);
268 if (memcmp(vce_hash, hash, vc_hash_length) == 0)
269 return 0;
270
271 pr_dbf_msg("SHA256 hash of received certificate does not match");
272 debug_text_event(cert_store_hexdump, 3, "VCE hash:");
273 debug_event(cert_store_hexdump, 3, vce_hash, SHA256_DIGEST_SIZE);
274 debug_text_event(cert_store_hexdump, 3, "Calculated hash:");
275 debug_event(cert_store_hexdump, 3, hash, SHA256_DIGEST_SIZE);
276
277 return -EINVAL;
278}
279
280static int check_certificate_valid(const struct vce *vce)
281{
282 if (!(vce->vce_hdr.flags & VCE_FLAGS_VALID_MASK)) {
283 pr_dbf_msg("Certificate entry is invalid");
284 return -EINVAL;
285 }
286 if (vce->vce_hdr.vc_format != 1) {
287 pr_dbf_msg("Certificate format is not supported");
288 return -EINVAL;
289 }
290 if (vce->vce_hdr.vc_hash_type != 1) {
291 pr_dbf_msg("Hash type is not supported");
292 return -EINVAL;
293 }
294
295 return check_certificate_hash(vce);
296}
297
298static struct key *get_user_session_keyring(void)
299{
300 key_ref_t us_keyring_ref;
301
302 us_keyring_ref = lookup_user_key(KEY_SPEC_USER_SESSION_KEYRING,
303 KEY_LOOKUP_CREATE, KEY_NEED_LINK);
304 if (IS_ERR(us_keyring_ref)) {
305 pr_dbf_msg("Couldn't get user session keyring: %ld",
306 PTR_ERR(us_keyring_ref));
307 return ERR_PTR(-ENOKEY);
308 }
309 key_ref_put(us_keyring_ref);
310 return key_ref_to_ptr(us_keyring_ref);
311}
312
313/* Invalidate all keys from cert_store keyring. */
314static int invalidate_keyring_keys(struct key *keyring)
315{
316 unsigned long num_keys, key_index;
317 size_t keyring_payload_len;
318 key_serial_t *key_array;
319 struct key *current_key;
320 int rc;
321
322 keyring_payload_len = key_type_keyring.read(keyring, NULL, 0);
323 num_keys = keyring_payload_len / sizeof(key_serial_t);
324 key_array = kcalloc(num_keys, sizeof(key_serial_t), GFP_KERNEL);
325 if (!key_array)
326 return -ENOMEM;
327
328 rc = key_type_keyring.read(keyring, (char *)key_array, keyring_payload_len);
329 if (rc != keyring_payload_len) {
330 pr_dbf_msg("Couldn't read keyring payload");
331 goto out;
332 }
333
334 for (key_index = 0; key_index < num_keys; key_index++) {
335 current_key = key_lookup(key_array[key_index]);
336 pr_dbf_msg("Invalidating key %08x", current_key->serial);
337
338 key_invalidate(current_key);
339 key_put(current_key);
340 rc = key_unlink(keyring, current_key);
341 if (rc) {
342 pr_dbf_msg("Couldn't unlink key %08x: %d", current_key->serial, rc);
343 break;
344 }
345 }
346out:
347 kfree(key_array);
348 return rc;
349}
350
351static struct key *find_cs_keyring(void)
352{
353 key_ref_t cs_keyring_ref;
354 struct key *cs_keyring;
355
356 cs_keyring_ref = keyring_search(make_key_ref(get_user_session_keyring(), true),
357 &key_type_keyring, CERT_STORE_KEYRING_NAME,
358 false);
359 if (!IS_ERR(cs_keyring_ref)) {
360 cs_keyring = key_ref_to_ptr(cs_keyring_ref);
361 key_ref_put(cs_keyring_ref);
362 goto found;
363 }
364 /* Search default locations: thread, process, session keyrings */
365 cs_keyring = request_key(&key_type_keyring, CERT_STORE_KEYRING_NAME, NULL);
366 if (IS_ERR(cs_keyring))
367 return NULL;
368 key_put(cs_keyring);
369found:
370 return cs_keyring;
371}
372
373static void cleanup_cs_keys(void)
374{
375 struct key *cs_keyring;
376
377 cs_keyring = find_cs_keyring();
378 if (!cs_keyring)
379 return;
380
381 pr_dbf_msg("Found cert_store keyring. Purging...");
382 /*
383 * Remove cert_store_key_type in case invalidation
384 * of old cert_store keys failed (= severe error).
385 */
386 if (invalidate_keyring_keys(cs_keyring))
387 unregister_key_type(&key_type_cert_store_key);
388
389 keyring_clear(cs_keyring);
390 key_invalidate(cs_keyring);
391 key_put(cs_keyring);
392 key_unlink(get_user_session_keyring(), cs_keyring);
393}
394
395static struct key *create_cs_keyring(void)
396{
397 static struct key *cs_keyring;
398
399 /* Cleanup previous cs_keyring and all associated keys if any. */
400 cleanup_cs_keys();
401 cs_keyring = keyring_alloc(CERT_STORE_KEYRING_NAME, GLOBAL_ROOT_UID,
402 GLOBAL_ROOT_GID, current_cred(),
403 (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ,
404 KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_SET_KEEP,
405 NULL, get_user_session_keyring());
406 if (IS_ERR(cs_keyring)) {
407 pr_dbf_msg("Can't allocate cert_store keyring");
408 return NULL;
409 }
410
411 pr_dbf_msg("Successfully allocated cert_store keyring: %08x", cs_keyring->serial);
412
413 /*
414 * In case a previous clean-up ran into an
415 * error and unregistered key type.
416 */
417 register_key_type(&key_type_cert_store_key);
418
419 return cs_keyring;
420}
421
422/*
423 * Allocate memory and create key description in format
424 * [key name in EBCDIC]:[VCE index]:[CS token].
425 * Return a pointer to key description or NULL if memory
426 * allocation failed. Memory should be freed by caller.
427 */
428static char *get_key_description(struct vcssb *vcssb, const struct vce *vce)
429{
430 size_t len, name_len;
431 u32 cs_token;
432 char *desc;
433
434 cs_token = vcssb->cs_token;
435 /* Description string contains "%64s:%04u:%08u\0". */
436 name_len = sizeof(vce->vce_hdr.vc_name);
437 len = name_len + 1 + 4 + 1 + 8 + 1;
438 desc = kmalloc(len, GFP_KERNEL);
439 if (!desc)
440 return NULL;
441
442 memcpy(desc, vce->vce_hdr.vc_name, name_len);
443 sprintf(desc + name_len, ":%04u:%08u", vce->vce_hdr.vc_index, cs_token);
444
445 return desc;
446}
447
448/*
449 * Create a key of type "cert_store_key" using the data from VCE for key
450 * payload and key description. Link the key to "cert_store" keyring.
451 */
452static int create_key_from_vce(struct vcssb *vcssb, struct vce *vce,
453 struct key *keyring)
454{
455 key_ref_t newkey;
456 char *desc;
457 int rc;
458
459 desc = get_key_description(vcssb, vce);
460 if (!desc)
461 return -ENOMEM;
462
463 newkey = key_create_or_update(
464 make_key_ref(keyring, true), CERT_STORE_KEY_TYPE_NAME,
465 desc, (u8 *)vce + vce->vce_hdr.vc_offset,
466 vce->vce_hdr.vc_length,
467 (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ,
468 KEY_ALLOC_NOT_IN_QUOTA);
469
470 rc = PTR_ERR_OR_ZERO(newkey);
471 if (rc) {
472 pr_dbf_msg("Couldn't create a key from Certificate Entry (%d)", rc);
473 rc = -ENOKEY;
474 goto out;
475 }
476
477 key_ref_put(newkey);
478out:
479 kfree(desc);
480 return rc;
481}
482
483/* Get Verification Certificate Storage Size block with DIAG320 subcode2. */
484static int get_vcssb(struct vcssb *vcssb)
485{
486 int diag320_rc;
487
488 memset(vcssb, 0, sizeof(*vcssb));
489 vcssb->vcssb_length = VCSSB_LEN_BYTES;
490 diag320_rc = diag320(DIAG320_STORAGE, vcssb);
491 pr_dbf_vcssb(vcssb);
492
493 if (diag320_rc != DIAG320_RC_OK) {
494 pr_dbf_msg("Diag 320 Subcode 1 returned bad RC: %04x", diag320_rc);
495 return -EIO;
496 }
497 if (vcssb->vcssb_length == VCSSB_LEN_NO_CERTS) {
498 pr_dbf_msg("No certificates available for current configuration");
499 return -ENOKEY;
500 }
501
502 return 0;
503}
504
505static u32 get_4k_mult_vcb_size(struct vcssb *vcssb)
506{
507 return round_up(vcssb->max_single_vcb_length, PAGE_SIZE);
508}
509
510/* Fill input fields of single-entry VCB that will be read by LPAR. */
511static void fill_vcb_input(struct vcssb *vcssb, struct vcb *vcb, u16 index)
512{
513 memset(vcb, 0, sizeof(*vcb));
514 vcb->vcb_hdr.vcb_input_length = get_4k_mult_vcb_size(vcssb);
515 vcb->vcb_hdr.cs_token = vcssb->cs_token;
516
517 /* Request single entry. */
518 vcb->vcb_hdr.first_vc_index = index;
519 vcb->vcb_hdr.last_vc_index = index;
520}
521
522static void extract_vce_from_sevcb(struct vcb *vcb, struct vce *vce)
523{
524 struct vce *extracted_vce;
525
526 extracted_vce = (struct vce *)vcb->vcb_buf;
527 memcpy(vce, vcb->vcb_buf, extracted_vce->vce_hdr.vce_length);
528 pr_dbf_vce(vce);
529}
530
531static int get_sevcb(struct vcssb *vcssb, u16 index, struct vcb *vcb)
532{
533 int rc, diag320_rc;
534
535 fill_vcb_input(vcssb, vcb, index);
536
537 diag320_rc = diag320(DIAG320_CERT_BLOCK, vcb);
538 pr_dbf_msg("Diag 320 Subcode2 RC %2x", diag320_rc);
539 pr_dbf_vcb(vcb);
540
541 switch (diag320_rc) {
542 case DIAG320_RC_OK:
543 rc = 0;
544 if (vcb->vcb_hdr.vcb_output_length == VCB_LEN_NO_CERTS) {
545 pr_dbf_msg("No certificate entry for index %u", index);
546 rc = -ENOKEY;
547 } else if (vcb->vcb_hdr.remaining_vc_count != 0) {
548 /* Retry on insufficient space. */
549 pr_dbf_msg("Couldn't get all requested certificates");
550 rc = -EAGAIN;
551 }
552 break;
553 case DIAG320_RC_CS_NOMATCH:
554 pr_dbf_msg("Certificate Store token mismatch");
555 rc = -EAGAIN;
556 break;
557 default:
558 pr_dbf_msg("Diag 320 Subcode2 returned bad rc (0x%4x)", diag320_rc);
559 rc = -EINVAL;
560 break;
561 }
562
563 return rc;
564}
565
566/*
567 * Allocate memory for single-entry VCB, get VCB via DIAG320 subcode 2 call,
568 * extract VCE and create a key from its' certificate.
569 */
570static int create_key_from_sevcb(struct vcssb *vcssb, u16 index,
571 struct key *keyring)
572{
573 struct vcb *vcb;
574 struct vce *vce;
575 int rc;
576
577 rc = -ENOMEM;
578 vcb = vmalloc(get_4k_mult_vcb_size(vcssb));
579 vce = vmalloc(vcssb->max_single_vcb_length - sizeof(vcb->vcb_hdr));
580 if (!vcb || !vce)
581 goto out;
582
583 rc = get_sevcb(vcssb, index, vcb);
584 if (rc)
585 goto out;
586
587 extract_vce_from_sevcb(vcb, vce);
588 rc = check_certificate_valid(vce);
589 if (rc)
590 goto out;
591
592 rc = create_key_from_vce(vcssb, vce, keyring);
593 if (rc)
594 goto out;
595
596 pr_dbf_msg("Successfully created key from Certificate Entry %d", index);
597out:
598 vfree(vce);
599 vfree(vcb);
600 return rc;
601}
602
603/*
604 * Request a single-entry VCB for each VCE available for the partition.
605 * Create a key from it and link it to cert_store keyring. If no keys
606 * could be created (i.e. VCEs were invalid) return -ENOKEY.
607 */
608static int add_certificates_to_keyring(struct vcssb *vcssb, struct key *keyring)
609{
610 int rc, index, count, added;
611
612 count = 0;
613 added = 0;
614 /* Certificate Store entries indices start with 1 and have no gaps. */
615 for (index = 1; index < vcssb->total_vc_index_count + 1; index++) {
616 pr_dbf_msg("Creating key from VCE %u", index);
617 rc = create_key_from_sevcb(vcssb, index, keyring);
618 count++;
619
620 if (rc == -EAGAIN)
621 return rc;
622
623 if (rc)
624 pr_dbf_msg("Creating key from VCE %u failed (%d)", index, rc);
625 else
626 added++;
627 }
628
629 if (added == 0) {
630 pr_dbf_msg("Processed %d entries. No keys created", count);
631 return -ENOKEY;
632 }
633
634 pr_info("Added %d of %d keys to cert_store keyring", added, count);
635
636 /*
637 * Do not allow to link more keys to certificate store keyring after all
638 * the VCEs were processed.
639 */
640 rc = keyring_restrict(make_key_ref(keyring, true), NULL, NULL);
641 if (rc)
642 pr_dbf_msg("Failed to set restriction to cert_store keyring (%d)", rc);
643
644 return 0;
645}
646
647/*
648 * Check which DIAG320 subcodes are installed.
649 * Return -ENOENT if subcodes 1 or 2 are not available.
650 */
651static int query_diag320_subcodes(void)
652{
653 unsigned long ism[ISM_LEN_DWORDS];
654 int rc;
655
656 rc = diag320(0, ism);
657 if (rc != DIAG320_RC_OK) {
658 pr_dbf_msg("DIAG320 subcode query returned %04x", rc);
659 return -ENOENT;
660 }
661
662 debug_text_event(cert_store_hexdump, 3, "DIAG320 Subcode 0");
663 debug_event(cert_store_hexdump, 3, ism, sizeof(ism));
664
665 if (!test_bit_inv(1, ism) || !test_bit_inv(2, ism)) {
666 pr_dbf_msg("Not all required DIAG320 subcodes are installed");
667 return -ENOENT;
668 }
669
670 return 0;
671}
672
673/*
674 * Check if Certificate Store is supported by the firmware and DIAG320 subcodes
675 * 1 and 2 are installed. Create cert_store keyring and link all certificates
676 * available for the current partition to it as "cert_store_key" type
677 * keys. On refresh or error invalidate cert_store keyring and destroy
678 * all keys of "cert_store_key" type.
679 */
680static int fill_cs_keyring(void)
681{
682 struct key *cs_keyring;
683 struct vcssb *vcssb;
684 int rc;
685
686 rc = -ENOMEM;
687 vcssb = kmalloc(VCSSB_LEN_BYTES, GFP_KERNEL);
688 if (!vcssb)
689 goto cleanup_keys;
690
691 rc = -ENOENT;
692 if (!sclp.has_diag320) {
693 pr_dbf_msg("Certificate Store is not supported");
694 goto cleanup_keys;
695 }
696
697 rc = query_diag320_subcodes();
698 if (rc)
699 goto cleanup_keys;
700
701 rc = get_vcssb(vcssb);
702 if (rc)
703 goto cleanup_keys;
704
3e8fc2d4 705 rc = -ENOMEM;
8cf57d72
AE		 706 cs_keyring = create_cs_keyring();
707 if (!cs_keyring)
708 goto cleanup_keys;
709
710 rc = add_certificates_to_keyring(vcssb, cs_keyring);
711 if (rc)
712 goto cleanup_cs_keyring;
713
714 goto out;
715
716cleanup_cs_keyring:
717 key_put(cs_keyring);
718cleanup_keys:
719 cleanup_cs_keys();
720out:
721 kfree(vcssb);
722 return rc;
723}
724
725static DEFINE_MUTEX(cs_refresh_lock);
726static int cs_status_val = -1;
727
728static ssize_t cs_status_show(struct kobject *kobj,
729 struct kobj_attribute *attr, char *buf)
730{
731 if (cs_status_val == -1)
732 return sysfs_emit(buf, "uninitialized\n");
733 else if (cs_status_val == 0)
734 return sysfs_emit(buf, "ok\n");
735
736 return sysfs_emit(buf, "failed (%d)\n", cs_status_val);
737}
738
739static struct kobj_attribute cs_status_attr = __ATTR_RO(cs_status);
740
741static ssize_t refresh_store(struct kobject *kobj, struct kobj_attribute *attr,
742 const char *buf, size_t count)
743{
744 int rc, retries;
745
746 pr_dbf_msg("Refresh certificate store information requested");
747 rc = mutex_lock_interruptible(&cs_refresh_lock);
748 if (rc)
749 return rc;
750
751 for (retries = 0; retries < DIAG_MAX_RETRIES; retries++) {
752 /* Request certificates from certificate store. */
753 rc = fill_cs_keyring();
754 if (rc)
755 pr_dbf_msg("Failed to refresh certificate store information (%d)", rc);
756 if (rc != -EAGAIN)
757 break;
758 }
759 cs_status_val = rc;
760 mutex_unlock(&cs_refresh_lock);
761
762 return rc ?: count;
763}
764
765static struct kobj_attribute refresh_attr = __ATTR_WO(refresh);
766
767static const struct attribute *cert_store_attrs[] __initconst = {
768 &cs_status_attr.attr,
769 &refresh_attr.attr,
770 NULL,
771};
772
773static struct kobject *cert_store_kobj;
774
775static int __init cert_store_init(void)
776{
777 int rc = -ENOMEM;
778
779 cert_store_dbf = debug_register("cert_store_msg", 10, 1, 64);
780 if (!cert_store_dbf)
781 goto cleanup_dbf;
782
783 cert_store_hexdump = debug_register("cert_store_hexdump", 3, 1, 128);
784 if (!cert_store_hexdump)
785 goto cleanup_dbf;
786
787 debug_register_view(cert_store_hexdump, &debug_hex_ascii_view);
788 debug_register_view(cert_store_dbf, &debug_sprintf_view);
789
790 /* Create directory /sys/firmware/cert_store. */
791 cert_store_kobj = kobject_create_and_add("cert_store", firmware_kobj);
792 if (!cert_store_kobj)
793 goto cleanup_dbf;
794
795 rc = sysfs_create_files(cert_store_kobj, cert_store_attrs);
796 if (rc)
797 goto cleanup_kobj;
798
799 register_key_type(&key_type_cert_store_key);
800
801 return rc;
802
803cleanup_kobj:
804 kobject_put(cert_store_kobj);
805cleanup_dbf:
806 debug_unregister(cert_store_dbf);
807 debug_unregister(cert_store_hexdump);
808
809 return rc;
810}
811device_initcall(cert_store_init);
Linux 6.x block layer and io_uring tree(s)