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 <linux/vmalloc.h> 25 #include <crypto/sha2.h> 26 #include <keys/user-type.h> 27 #include <asm/debug.h> 28 #include <asm/diag.h> 29 #include <asm/ebcdic.h> 30 #include <asm/sclp.h> 31 32 #define DIAG_MAX_RETRIES 10 33 34 #define VCE_FLAGS_VALID_MASK 0x80 35 36 #define ISM_LEN_DWORDS 4 37 #define VCSSB_LEN_BYTES 128 38 #define VCSSB_LEN_NO_CERTS 4 39 #define VCB_LEN_NO_CERTS 64 40 #define VC_NAME_LEN_BYTES 64 41 42 #define CERT_STORE_KEY_TYPE_NAME "cert_store_key" 43 #define CERT_STORE_KEYRING_NAME "cert_store" 44 45 static debug_info_t *cert_store_dbf; 46 static debug_info_t *cert_store_hexdump; 47 48 #define pr_dbf_msg(fmt, ...) \ 49 debug_sprintf_event(cert_store_dbf, 3, fmt "\n", ## __VA_ARGS__) 50 51 enum diag320_subcode { 52 DIAG320_SUBCODES = 0, 53 DIAG320_STORAGE = 1, 54 DIAG320_CERT_BLOCK = 2, 55 }; 56 57 enum diag320_rc { 58 DIAG320_RC_OK = 0x0001, 59 DIAG320_RC_CS_NOMATCH = 0x0306, 60 }; 61 62 /* Verification Certificates Store Support Block (VCSSB). */ 63 struct vcssb { 64 u32 vcssb_length; 65 u8 pad_0x04[3]; 66 u8 version; 67 u8 pad_0x08[8]; 68 u32 cs_token; 69 u8 pad_0x14[12]; 70 u16 total_vc_index_count; 71 u16 max_vc_index_count; 72 u8 pad_0x24[28]; 73 u32 max_vce_length; 74 u32 max_vcxe_length; 75 u8 pad_0x48[8]; 76 u32 max_single_vcb_length; 77 u32 total_vcb_length; 78 u32 max_single_vcxb_length; 79 u32 total_vcxb_length; 80 u8 pad_0x60[32]; 81 } __packed __aligned(8); 82 83 /* Verification Certificate Entry (VCE) Header. */ 84 struct vce_header { 85 u32 vce_length; 86 u8 flags; 87 u8 key_type; 88 u16 vc_index; 89 u8 vc_name[VC_NAME_LEN_BYTES]; /* EBCDIC */ 90 u8 vc_format; 91 u8 pad_0x49; 92 u16 key_id_length; 93 u8 pad_0x4c; 94 u8 vc_hash_type; 95 u16 vc_hash_length; 96 u8 pad_0x50[4]; 97 u32 vc_length; 98 u8 pad_0x58[8]; 99 u16 vc_hash_offset; 100 u16 vc_offset; 101 u8 pad_0x64[28]; 102 } __packed __aligned(4); 103 104 /* Verification Certificate Block (VCB) Header. */ 105 struct vcb_header { 106 u32 vcb_input_length; 107 u8 pad_0x04[4]; 108 u16 first_vc_index; 109 u16 last_vc_index; 110 u32 pad_0x0c; 111 u32 cs_token; 112 u8 pad_0x14[12]; 113 u32 vcb_output_length; 114 u8 pad_0x24[3]; 115 u8 version; 116 u16 stored_vc_count; 117 u16 remaining_vc_count; 118 u8 pad_0x2c[20]; 119 } __packed __aligned(4); 120 121 /* Verification Certificate Block (VCB). */ 122 struct vcb { 123 struct vcb_header vcb_hdr; 124 u8 vcb_buf[]; 125 } __packed __aligned(4); 126 127 /* Verification Certificate Entry (VCE). */ 128 struct vce { 129 struct vce_header vce_hdr; 130 u8 cert_data_buf[]; 131 } __packed __aligned(4); 132 133 static void cert_store_key_describe(const struct key *key, struct seq_file *m) 134 { 135 char ascii[VC_NAME_LEN_BYTES + 1]; 136 137 /* 138 * First 64 bytes of the key description is key name in EBCDIC CP 500. 139 * Convert it to ASCII for displaying in /proc/keys. 140 */ 141 strscpy(ascii, key->description, sizeof(ascii)); 142 EBCASC_500(ascii, VC_NAME_LEN_BYTES); 143 seq_puts(m, ascii); 144 145 seq_puts(m, &key->description[VC_NAME_LEN_BYTES]); 146 if (key_is_positive(key)) 147 seq_printf(m, ": %u", key->datalen); 148 } 149 150 /* 151 * Certificate store key type takes over properties of 152 * user key but cannot be updated. 153 */ 154 static struct key_type key_type_cert_store_key = { 155 .name = CERT_STORE_KEY_TYPE_NAME, 156 .preparse = user_preparse, 157 .free_preparse = user_free_preparse, 158 .instantiate = generic_key_instantiate, 159 .revoke = user_revoke, 160 .destroy = user_destroy, 161 .describe = cert_store_key_describe, 162 .read = user_read, 163 }; 164 165 /* Logging functions. */ 166 static void pr_dbf_vcb(const struct vcb *b) 167 { 168 pr_dbf_msg("VCB Header:"); 169 pr_dbf_msg("vcb_input_length: %d", b->vcb_hdr.vcb_input_length); 170 pr_dbf_msg("first_vc_index: %d", b->vcb_hdr.first_vc_index); 171 pr_dbf_msg("last_vc_index: %d", b->vcb_hdr.last_vc_index); 172 pr_dbf_msg("cs_token: %d", b->vcb_hdr.cs_token); 173 pr_dbf_msg("vcb_output_length: %d", b->vcb_hdr.vcb_output_length); 174 pr_dbf_msg("version: %d", b->vcb_hdr.version); 175 pr_dbf_msg("stored_vc_count: %d", b->vcb_hdr.stored_vc_count); 176 pr_dbf_msg("remaining_vc_count: %d", b->vcb_hdr.remaining_vc_count); 177 } 178 179 static void pr_dbf_vce(const struct vce *e) 180 { 181 unsigned char vc_name[VC_NAME_LEN_BYTES + 1]; 182 char log_string[VC_NAME_LEN_BYTES + 40]; 183 184 pr_dbf_msg("VCE Header:"); 185 pr_dbf_msg("vce_hdr.vce_length: %d", e->vce_hdr.vce_length); 186 pr_dbf_msg("vce_hdr.flags: %d", e->vce_hdr.flags); 187 pr_dbf_msg("vce_hdr.key_type: %d", e->vce_hdr.key_type); 188 pr_dbf_msg("vce_hdr.vc_index: %d", e->vce_hdr.vc_index); 189 pr_dbf_msg("vce_hdr.vc_format: %d", e->vce_hdr.vc_format); 190 pr_dbf_msg("vce_hdr.key_id_length: %d", e->vce_hdr.key_id_length); 191 pr_dbf_msg("vce_hdr.vc_hash_type: %d", e->vce_hdr.vc_hash_type); 192 pr_dbf_msg("vce_hdr.vc_hash_length: %d", e->vce_hdr.vc_hash_length); 193 pr_dbf_msg("vce_hdr.vc_hash_offset: %d", e->vce_hdr.vc_hash_offset); 194 pr_dbf_msg("vce_hdr.vc_length: %d", e->vce_hdr.vc_length); 195 pr_dbf_msg("vce_hdr.vc_offset: %d", e->vce_hdr.vc_offset); 196 197 /* Certificate name in ASCII. */ 198 memcpy(vc_name, e->vce_hdr.vc_name, VC_NAME_LEN_BYTES); 199 EBCASC_500(vc_name, VC_NAME_LEN_BYTES); 200 vc_name[VC_NAME_LEN_BYTES] = '\0'; 201 202 snprintf(log_string, sizeof(log_string), 203 "index: %d vce_hdr.vc_name (ASCII): %s", 204 e->vce_hdr.vc_index, vc_name); 205 debug_text_event(cert_store_hexdump, 3, log_string); 206 207 /* Certificate data. */ 208 debug_text_event(cert_store_hexdump, 3, "VCE: Certificate data start"); 209 debug_event(cert_store_hexdump, 3, (u8 *)e->cert_data_buf, 128); 210 debug_text_event(cert_store_hexdump, 3, "VCE: Certificate data end"); 211 debug_event(cert_store_hexdump, 3, 212 (u8 *)e->cert_data_buf + e->vce_hdr.vce_length - 128, 128); 213 } 214 215 static void pr_dbf_vcssb(const struct vcssb *s) 216 { 217 debug_text_event(cert_store_hexdump, 3, "DIAG320 Subcode1"); 218 debug_event(cert_store_hexdump, 3, (u8 *)s, VCSSB_LEN_BYTES); 219 220 pr_dbf_msg("VCSSB:"); 221 pr_dbf_msg("vcssb_length: %u", s->vcssb_length); 222 pr_dbf_msg("version: %u", s->version); 223 pr_dbf_msg("cs_token: %u", s->cs_token); 224 pr_dbf_msg("total_vc_index_count: %u", s->total_vc_index_count); 225 pr_dbf_msg("max_vc_index_count: %u", s->max_vc_index_count); 226 pr_dbf_msg("max_vce_length: %u", s->max_vce_length); 227 pr_dbf_msg("max_vcxe_length: %u", s->max_vce_length); 228 pr_dbf_msg("max_single_vcb_length: %u", s->max_single_vcb_length); 229 pr_dbf_msg("total_vcb_length: %u", s->total_vcb_length); 230 pr_dbf_msg("max_single_vcxb_length: %u", s->max_single_vcxb_length); 231 pr_dbf_msg("total_vcxb_length: %u", s->total_vcxb_length); 232 } 233 234 static int __diag320(unsigned long subcode, void *addr) 235 { 236 union register_pair rp = { .even = (unsigned long)addr, }; 237 238 asm volatile( 239 " diag %[rp],%[subcode],0x320\n" 240 "0: nopr %%r7\n" 241 EX_TABLE(0b, 0b) 242 : [rp] "+d" (rp.pair) 243 : [subcode] "d" (subcode) 244 : "cc", "memory"); 245 246 return rp.odd; 247 } 248 249 static int diag320(unsigned long subcode, void *addr) 250 { 251 diag_stat_inc(DIAG_STAT_X320); 252 253 return __diag320(subcode, addr); 254 } 255 256 /* 257 * Calculate SHA256 hash of the VCE certificate and compare it to hash stored in 258 * VCE. Return -EINVAL if hashes don't match. 259 */ 260 static int check_certificate_hash(const struct vce *vce) 261 { 262 u8 hash[SHA256_DIGEST_SIZE]; 263 u16 vc_hash_length; 264 u8 *vce_hash; 265 266 vce_hash = (u8 *)vce + vce->vce_hdr.vc_hash_offset; 267 vc_hash_length = vce->vce_hdr.vc_hash_length; 268 sha256((u8 *)vce + vce->vce_hdr.vc_offset, vce->vce_hdr.vc_length, hash); 269 if (memcmp(vce_hash, hash, vc_hash_length) == 0) 270 return 0; 271 272 pr_dbf_msg("SHA256 hash of received certificate does not match"); 273 debug_text_event(cert_store_hexdump, 3, "VCE hash:"); 274 debug_event(cert_store_hexdump, 3, vce_hash, SHA256_DIGEST_SIZE); 275 debug_text_event(cert_store_hexdump, 3, "Calculated hash:"); 276 debug_event(cert_store_hexdump, 3, hash, SHA256_DIGEST_SIZE); 277 278 return -EINVAL; 279 } 280 281 static int check_certificate_valid(const struct vce *vce) 282 { 283 if (!(vce->vce_hdr.flags & VCE_FLAGS_VALID_MASK)) { 284 pr_dbf_msg("Certificate entry is invalid"); 285 return -EINVAL; 286 } 287 if (vce->vce_hdr.vc_format != 1) { 288 pr_dbf_msg("Certificate format is not supported"); 289 return -EINVAL; 290 } 291 if (vce->vce_hdr.vc_hash_type != 1) { 292 pr_dbf_msg("Hash type is not supported"); 293 return -EINVAL; 294 } 295 296 return check_certificate_hash(vce); 297 } 298 299 static struct key *get_user_session_keyring(void) 300 { 301 key_ref_t us_keyring_ref; 302 303 us_keyring_ref = lookup_user_key(KEY_SPEC_USER_SESSION_KEYRING, 304 KEY_LOOKUP_CREATE, KEY_NEED_LINK); 305 if (IS_ERR(us_keyring_ref)) { 306 pr_dbf_msg("Couldn't get user session keyring: %ld", 307 PTR_ERR(us_keyring_ref)); 308 return ERR_PTR(-ENOKEY); 309 } 310 key_ref_put(us_keyring_ref); 311 return key_ref_to_ptr(us_keyring_ref); 312 } 313 314 /* Invalidate all keys from cert_store keyring. */ 315 static int invalidate_keyring_keys(struct key *keyring) 316 { 317 unsigned long num_keys, key_index; 318 size_t keyring_payload_len; 319 key_serial_t *key_array; 320 struct key *current_key; 321 int rc; 322 323 keyring_payload_len = key_type_keyring.read(keyring, NULL, 0); 324 num_keys = keyring_payload_len / sizeof(key_serial_t); 325 key_array = kcalloc(num_keys, sizeof(key_serial_t), GFP_KERNEL); 326 if (!key_array) 327 return -ENOMEM; 328 329 rc = key_type_keyring.read(keyring, (char *)key_array, keyring_payload_len); 330 if (rc != keyring_payload_len) { 331 pr_dbf_msg("Couldn't read keyring payload"); 332 goto out; 333 } 334 335 for (key_index = 0; key_index < num_keys; key_index++) { 336 current_key = key_lookup(key_array[key_index]); 337 pr_dbf_msg("Invalidating key %08x", current_key->serial); 338 339 key_invalidate(current_key); 340 key_put(current_key); 341 rc = key_unlink(keyring, current_key); 342 if (rc) { 343 pr_dbf_msg("Couldn't unlink key %08x: %d", current_key->serial, rc); 344 break; 345 } 346 } 347 out: 348 kfree(key_array); 349 return rc; 350 } 351 352 static struct key *find_cs_keyring(void) 353 { 354 key_ref_t cs_keyring_ref; 355 struct key *cs_keyring; 356 357 cs_keyring_ref = keyring_search(make_key_ref(get_user_session_keyring(), true), 358 &key_type_keyring, CERT_STORE_KEYRING_NAME, 359 false); 360 if (!IS_ERR(cs_keyring_ref)) { 361 cs_keyring = key_ref_to_ptr(cs_keyring_ref); 362 key_ref_put(cs_keyring_ref); 363 goto found; 364 } 365 /* Search default locations: thread, process, session keyrings */ 366 cs_keyring = request_key(&key_type_keyring, CERT_STORE_KEYRING_NAME, NULL); 367 if (IS_ERR(cs_keyring)) 368 return NULL; 369 key_put(cs_keyring); 370 found: 371 return cs_keyring; 372 } 373 374 static void cleanup_cs_keys(void) 375 { 376 struct key *cs_keyring; 377 378 cs_keyring = find_cs_keyring(); 379 if (!cs_keyring) 380 return; 381 382 pr_dbf_msg("Found cert_store keyring. Purging..."); 383 /* 384 * Remove cert_store_key_type in case invalidation 385 * of old cert_store keys failed (= severe error). 386 */ 387 if (invalidate_keyring_keys(cs_keyring)) 388 unregister_key_type(&key_type_cert_store_key); 389 390 keyring_clear(cs_keyring); 391 key_invalidate(cs_keyring); 392 key_put(cs_keyring); 393 key_unlink(get_user_session_keyring(), cs_keyring); 394 } 395 396 static struct key *create_cs_keyring(void) 397 { 398 static struct key *cs_keyring; 399 400 /* Cleanup previous cs_keyring and all associated keys if any. */ 401 cleanup_cs_keys(); 402 cs_keyring = keyring_alloc(CERT_STORE_KEYRING_NAME, GLOBAL_ROOT_UID, 403 GLOBAL_ROOT_GID, current_cred(), 404 (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ, 405 KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_SET_KEEP, 406 NULL, get_user_session_keyring()); 407 if (IS_ERR(cs_keyring)) { 408 pr_dbf_msg("Can't allocate cert_store keyring"); 409 return NULL; 410 } 411 412 pr_dbf_msg("Successfully allocated cert_store keyring: %08x", cs_keyring->serial); 413 414 /* 415 * In case a previous clean-up ran into an 416 * error and unregistered key type. 417 */ 418 register_key_type(&key_type_cert_store_key); 419 420 return cs_keyring; 421 } 422 423 /* 424 * Allocate memory and create key description in format 425 * [key name in EBCDIC]:[VCE index]:[CS token]. 426 * Return a pointer to key description or NULL if memory 427 * allocation failed. Memory should be freed by caller. 428 */ 429 static char *get_key_description(struct vcssb *vcssb, const struct vce *vce) 430 { 431 size_t len, name_len; 432 u32 cs_token; 433 char *desc; 434 435 cs_token = vcssb->cs_token; 436 /* Description string contains "%64s:%05u:%010u\0". */ 437 name_len = sizeof(vce->vce_hdr.vc_name); 438 len = name_len + 1 + 5 + 1 + 10 + 1; 439 desc = kmalloc(len, GFP_KERNEL); 440 if (!desc) 441 return NULL; 442 443 memcpy(desc, vce->vce_hdr.vc_name, name_len); 444 snprintf(desc + name_len, len - name_len, ":%05u:%010u", 445 vce->vce_hdr.vc_index, cs_token); 446 447 return desc; 448 } 449 450 /* 451 * Create a key of type "cert_store_key" using the data from VCE for key 452 * payload and key description. Link the key to "cert_store" keyring. 453 */ 454 static int create_key_from_vce(struct vcssb *vcssb, struct vce *vce, 455 struct key *keyring) 456 { 457 key_ref_t newkey; 458 char *desc; 459 int rc; 460 461 desc = get_key_description(vcssb, vce); 462 if (!desc) 463 return -ENOMEM; 464 465 newkey = key_create_or_update( 466 make_key_ref(keyring, true), CERT_STORE_KEY_TYPE_NAME, 467 desc, (u8 *)vce + vce->vce_hdr.vc_offset, 468 vce->vce_hdr.vc_length, 469 (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ, 470 KEY_ALLOC_NOT_IN_QUOTA); 471 472 rc = PTR_ERR_OR_ZERO(newkey); 473 if (rc) { 474 pr_dbf_msg("Couldn't create a key from Certificate Entry (%d)", rc); 475 rc = -ENOKEY; 476 goto out; 477 } 478 479 key_ref_put(newkey); 480 out: 481 kfree(desc); 482 return rc; 483 } 484 485 /* Get Verification Certificate Storage Size block with DIAG320 subcode2. */ 486 static int get_vcssb(struct vcssb *vcssb) 487 { 488 int diag320_rc; 489 490 memset(vcssb, 0, sizeof(*vcssb)); 491 vcssb->vcssb_length = VCSSB_LEN_BYTES; 492 diag320_rc = diag320(DIAG320_STORAGE, vcssb); 493 pr_dbf_vcssb(vcssb); 494 495 if (diag320_rc != DIAG320_RC_OK) { 496 pr_dbf_msg("Diag 320 Subcode 1 returned bad RC: %04x", diag320_rc); 497 return -EIO; 498 } 499 if (vcssb->vcssb_length == VCSSB_LEN_NO_CERTS) { 500 pr_dbf_msg("No certificates available for current configuration"); 501 return -ENOKEY; 502 } 503 504 return 0; 505 } 506 507 static u32 get_4k_mult_vcb_size(struct vcssb *vcssb) 508 { 509 return round_up(vcssb->max_single_vcb_length, PAGE_SIZE); 510 } 511 512 /* Fill input fields of single-entry VCB that will be read by LPAR. */ 513 static void fill_vcb_input(struct vcssb *vcssb, struct vcb *vcb, u16 index) 514 { 515 memset(vcb, 0, sizeof(*vcb)); 516 vcb->vcb_hdr.vcb_input_length = get_4k_mult_vcb_size(vcssb); 517 vcb->vcb_hdr.cs_token = vcssb->cs_token; 518 519 /* Request single entry. */ 520 vcb->vcb_hdr.first_vc_index = index; 521 vcb->vcb_hdr.last_vc_index = index; 522 } 523 524 static void extract_vce_from_sevcb(struct vcb *vcb, struct vce *vce) 525 { 526 struct vce *extracted_vce; 527 528 extracted_vce = (struct vce *)vcb->vcb_buf; 529 memcpy(vce, vcb->vcb_buf, extracted_vce->vce_hdr.vce_length); 530 pr_dbf_vce(vce); 531 } 532 533 static int get_sevcb(struct vcssb *vcssb, u16 index, struct vcb *vcb) 534 { 535 int rc, diag320_rc; 536 537 fill_vcb_input(vcssb, vcb, index); 538 539 diag320_rc = diag320(DIAG320_CERT_BLOCK, vcb); 540 pr_dbf_msg("Diag 320 Subcode2 RC %2x", diag320_rc); 541 pr_dbf_vcb(vcb); 542 543 switch (diag320_rc) { 544 case DIAG320_RC_OK: 545 rc = 0; 546 if (vcb->vcb_hdr.vcb_output_length == VCB_LEN_NO_CERTS) { 547 pr_dbf_msg("No certificate entry for index %u", index); 548 rc = -ENOKEY; 549 } else if (vcb->vcb_hdr.remaining_vc_count != 0) { 550 /* Retry on insufficient space. */ 551 pr_dbf_msg("Couldn't get all requested certificates"); 552 rc = -EAGAIN; 553 } 554 break; 555 case DIAG320_RC_CS_NOMATCH: 556 pr_dbf_msg("Certificate Store token mismatch"); 557 rc = -EAGAIN; 558 break; 559 default: 560 pr_dbf_msg("Diag 320 Subcode2 returned bad rc (0x%4x)", diag320_rc); 561 rc = -EINVAL; 562 break; 563 } 564 565 return rc; 566 } 567 568 /* 569 * Allocate memory for single-entry VCB, get VCB via DIAG320 subcode 2 call, 570 * extract VCE and create a key from its' certificate. 571 */ 572 static int create_key_from_sevcb(struct vcssb *vcssb, u16 index, 573 struct key *keyring) 574 { 575 struct vcb *vcb; 576 struct vce *vce; 577 int rc; 578 579 rc = -ENOMEM; 580 vcb = vmalloc(get_4k_mult_vcb_size(vcssb)); 581 vce = vmalloc(vcssb->max_single_vcb_length - sizeof(vcb->vcb_hdr)); 582 if (!vcb || !vce) 583 goto out; 584 585 rc = get_sevcb(vcssb, index, vcb); 586 if (rc) 587 goto out; 588 589 extract_vce_from_sevcb(vcb, vce); 590 rc = check_certificate_valid(vce); 591 if (rc) 592 goto out; 593 594 rc = create_key_from_vce(vcssb, vce, keyring); 595 if (rc) 596 goto out; 597 598 pr_dbf_msg("Successfully created key from Certificate Entry %d", index); 599 out: 600 vfree(vce); 601 vfree(vcb); 602 return rc; 603 } 604 605 /* 606 * Request a single-entry VCB for each VCE available for the partition. 607 * Create a key from it and link it to cert_store keyring. If no keys 608 * could be created (i.e. VCEs were invalid) return -ENOKEY. 609 */ 610 static int add_certificates_to_keyring(struct vcssb *vcssb, struct key *keyring) 611 { 612 int rc, index, count, added; 613 614 count = 0; 615 added = 0; 616 /* Certificate Store entries indices start with 1 and have no gaps. */ 617 for (index = 1; index < vcssb->total_vc_index_count + 1; index++) { 618 pr_dbf_msg("Creating key from VCE %u", index); 619 rc = create_key_from_sevcb(vcssb, index, keyring); 620 count++; 621 622 if (rc == -EAGAIN) 623 return rc; 624 625 if (rc) 626 pr_dbf_msg("Creating key from VCE %u failed (%d)", index, rc); 627 else 628 added++; 629 } 630 631 if (added == 0) { 632 pr_dbf_msg("Processed %d entries. No keys created", count); 633 return -ENOKEY; 634 } 635 636 pr_info("Added %d of %d keys to cert_store keyring", added, count); 637 638 /* 639 * Do not allow to link more keys to certificate store keyring after all 640 * the VCEs were processed. 641 */ 642 rc = keyring_restrict(make_key_ref(keyring, true), NULL, NULL); 643 if (rc) 644 pr_dbf_msg("Failed to set restriction to cert_store keyring (%d)", rc); 645 646 return 0; 647 } 648 649 /* 650 * Check which DIAG320 subcodes are installed. 651 * Return -ENOENT if subcodes 1 or 2 are not available. 652 */ 653 static int query_diag320_subcodes(void) 654 { 655 unsigned long ism[ISM_LEN_DWORDS]; 656 int rc; 657 658 rc = diag320(0, ism); 659 if (rc != DIAG320_RC_OK) { 660 pr_dbf_msg("DIAG320 subcode query returned %04x", rc); 661 return -ENOENT; 662 } 663 664 debug_text_event(cert_store_hexdump, 3, "DIAG320 Subcode 0"); 665 debug_event(cert_store_hexdump, 3, ism, sizeof(ism)); 666 667 if (!test_bit_inv(1, ism) || !test_bit_inv(2, ism)) { 668 pr_dbf_msg("Not all required DIAG320 subcodes are installed"); 669 return -ENOENT; 670 } 671 672 return 0; 673 } 674 675 /* 676 * Check if Certificate Store is supported by the firmware and DIAG320 subcodes 677 * 1 and 2 are installed. Create cert_store keyring and link all certificates 678 * available for the current partition to it as "cert_store_key" type 679 * keys. On refresh or error invalidate cert_store keyring and destroy 680 * all keys of "cert_store_key" type. 681 */ 682 static int fill_cs_keyring(void) 683 { 684 struct key *cs_keyring; 685 struct vcssb *vcssb; 686 int rc; 687 688 rc = -ENOMEM; 689 vcssb = kmalloc(VCSSB_LEN_BYTES, GFP_KERNEL); 690 if (!vcssb) 691 goto cleanup_keys; 692 693 rc = -ENOENT; 694 if (!sclp.has_diag320) { 695 pr_dbf_msg("Certificate Store is not supported"); 696 goto cleanup_keys; 697 } 698 699 rc = query_diag320_subcodes(); 700 if (rc) 701 goto cleanup_keys; 702 703 rc = get_vcssb(vcssb); 704 if (rc) 705 goto cleanup_keys; 706 707 rc = -ENOMEM; 708 cs_keyring = create_cs_keyring(); 709 if (!cs_keyring) 710 goto cleanup_keys; 711 712 rc = add_certificates_to_keyring(vcssb, cs_keyring); 713 if (rc) 714 goto cleanup_cs_keyring; 715 716 goto out; 717 718 cleanup_cs_keyring: 719 key_put(cs_keyring); 720 cleanup_keys: 721 cleanup_cs_keys(); 722 out: 723 kfree(vcssb); 724 return rc; 725 } 726 727 static DEFINE_MUTEX(cs_refresh_lock); 728 static int cs_status_val = -1; 729 730 static ssize_t cs_status_show(struct kobject *kobj, 731 struct kobj_attribute *attr, char *buf) 732 { 733 if (cs_status_val == -1) 734 return sysfs_emit(buf, "uninitialized\n"); 735 else if (cs_status_val == 0) 736 return sysfs_emit(buf, "ok\n"); 737 738 return sysfs_emit(buf, "failed (%d)\n", cs_status_val); 739 } 740 741 static struct kobj_attribute cs_status_attr = __ATTR_RO(cs_status); 742 743 static ssize_t refresh_store(struct kobject *kobj, struct kobj_attribute *attr, 744 const char *buf, size_t count) 745 { 746 int rc, retries; 747 748 pr_dbf_msg("Refresh certificate store information requested"); 749 rc = mutex_lock_interruptible(&cs_refresh_lock); 750 if (rc) 751 return rc; 752 753 for (retries = 0; retries < DIAG_MAX_RETRIES; retries++) { 754 /* Request certificates from certificate store. */ 755 rc = fill_cs_keyring(); 756 if (rc) 757 pr_dbf_msg("Failed to refresh certificate store information (%d)", rc); 758 if (rc != -EAGAIN) 759 break; 760 } 761 cs_status_val = rc; 762 mutex_unlock(&cs_refresh_lock); 763 764 return rc ?: count; 765 } 766 767 static struct kobj_attribute refresh_attr = __ATTR_WO(refresh); 768 769 static const struct attribute *cert_store_attrs[] __initconst = { 770 &cs_status_attr.attr, 771 &refresh_attr.attr, 772 NULL, 773 }; 774 775 static struct kobject *cert_store_kobj; 776 777 static int __init cert_store_init(void) 778 { 779 int rc = -ENOMEM; 780 781 cert_store_dbf = debug_register("cert_store_msg", 10, 1, 64); 782 if (!cert_store_dbf) 783 goto cleanup_dbf; 784 785 cert_store_hexdump = debug_register("cert_store_hexdump", 3, 1, 128); 786 if (!cert_store_hexdump) 787 goto cleanup_dbf; 788 789 debug_register_view(cert_store_hexdump, &debug_hex_ascii_view); 790 debug_register_view(cert_store_dbf, &debug_sprintf_view); 791 792 /* Create directory /sys/firmware/cert_store. */ 793 cert_store_kobj = kobject_create_and_add("cert_store", firmware_kobj); 794 if (!cert_store_kobj) 795 goto cleanup_dbf; 796 797 rc = sysfs_create_files(cert_store_kobj, cert_store_attrs); 798 if (rc) 799 goto cleanup_kobj; 800 801 register_key_type(&key_type_cert_store_key); 802 803 return rc; 804 805 cleanup_kobj: 806 kobject_put(cert_store_kobj); 807 cleanup_dbf: 808 debug_unregister(cert_store_dbf); 809 debug_unregister(cert_store_hexdump); 810 811 return rc; 812 } 813 device_initcall(cert_store_init); 814