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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 | // SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2013 Politecnico di Torino, Italy * TORSEC group -- https://security.polito.it * * Author: Roberto Sassu <roberto.sassu@polito.it> * * File: ima_template_lib.c * Library of supported template fields. */ #include "ima_template_lib.h" #include <linux/xattr.h> #include <linux/evm.h> static bool ima_template_hash_algo_allowed(u8 algo) { if (algo == HASH_ALGO_SHA1 || algo == HASH_ALGO_MD5) return true; return false; } enum data_formats { DATA_FMT_DIGEST = 0, DATA_FMT_DIGEST_WITH_ALGO, DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO, DATA_FMT_STRING, DATA_FMT_HEX, DATA_FMT_UINT }; enum digest_type { DIGEST_TYPE_IMA, DIGEST_TYPE_VERITY, DIGEST_TYPE__LAST }; #define DIGEST_TYPE_NAME_LEN_MAX 7 /* including NUL */ static const char * const digest_type_name[DIGEST_TYPE__LAST] = { [DIGEST_TYPE_IMA] = "ima", [DIGEST_TYPE_VERITY] = "verity" }; static int ima_write_template_field_data(const void *data, const u32 datalen, enum data_formats datafmt, struct ima_field_data *field_data) { u8 *buf, *buf_ptr; u32 buflen = datalen; if (datafmt == DATA_FMT_STRING) buflen = datalen + 1; buf = kzalloc(buflen, GFP_KERNEL); if (!buf) return -ENOMEM; memcpy(buf, data, datalen); /* * Replace all space characters with underscore for event names and * strings. This avoid that, during the parsing of a measurements list, * filenames with spaces or that end with the suffix ' (deleted)' are * split into multiple template fields (the space is the delimitator * character for measurements lists in ASCII format). */ if (datafmt == DATA_FMT_STRING) { for (buf_ptr = buf; buf_ptr - buf < datalen; buf_ptr++) if (*buf_ptr == ' ') *buf_ptr = '_'; } field_data->data = buf; field_data->len = buflen; return 0; } static void ima_show_template_data_ascii(struct seq_file *m, enum ima_show_type show, enum data_formats datafmt, struct ima_field_data *field_data) { u8 *buf_ptr = field_data->data; u32 buflen = field_data->len; switch (datafmt) { case DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO: case DATA_FMT_DIGEST_WITH_ALGO: buf_ptr = strrchr(field_data->data, ':'); if (buf_ptr != field_data->data) seq_printf(m, "%s", field_data->data); /* skip ':' and '\0' */ buf_ptr += 2; buflen -= buf_ptr - field_data->data; fallthrough; case DATA_FMT_DIGEST: case DATA_FMT_HEX: if (!buflen) break; ima_print_digest(m, buf_ptr, buflen); break; case DATA_FMT_STRING: seq_printf(m, "%s", buf_ptr); break; case DATA_FMT_UINT: switch (field_data->len) { case sizeof(u8): seq_printf(m, "%u", *(u8 *)buf_ptr); break; case sizeof(u16): if (ima_canonical_fmt) seq_printf(m, "%u", le16_to_cpu(*(__le16 *)buf_ptr)); else seq_printf(m, "%u", *(u16 *)buf_ptr); break; case sizeof(u32): if (ima_canonical_fmt) seq_printf(m, "%u", le32_to_cpu(*(__le32 *)buf_ptr)); else seq_printf(m, "%u", *(u32 *)buf_ptr); break; case sizeof(u64): if (ima_canonical_fmt) seq_printf(m, "%llu", le64_to_cpu(*(__le64 *)buf_ptr)); else seq_printf(m, "%llu", *(u64 *)buf_ptr); break; default: break; } break; default: break; } } static void ima_show_template_data_binary(struct seq_file *m, enum ima_show_type show, enum data_formats datafmt, struct ima_field_data *field_data) { u32 len = (show == IMA_SHOW_BINARY_OLD_STRING_FMT) ? strlen(field_data->data) : field_data->len; if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) { u32 field_len = !ima_canonical_fmt ? len : (__force u32)cpu_to_le32(len); ima_putc(m, &field_len, sizeof(field_len)); } if (!len) return; ima_putc(m, field_data->data, len); } static void ima_show_template_field_data(struct seq_file *m, enum ima_show_type show, enum data_formats datafmt, struct ima_field_data *field_data) { switch (show) { case IMA_SHOW_ASCII: ima_show_template_data_ascii(m, show, datafmt, field_data); break; case IMA_SHOW_BINARY: case IMA_SHOW_BINARY_NO_FIELD_LEN: case IMA_SHOW_BINARY_OLD_STRING_FMT: ima_show_template_data_binary(m, show, datafmt, field_data); break; default: break; } } void ima_show_template_digest(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data) { ima_show_template_field_data(m, show, DATA_FMT_DIGEST, field_data); } void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data) { ima_show_template_field_data(m, show, DATA_FMT_DIGEST_WITH_ALGO, field_data); } void ima_show_template_digest_ngv2(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data) { ima_show_template_field_data(m, show, DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO, field_data); } void ima_show_template_string(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data) { ima_show_template_field_data(m, show, DATA_FMT_STRING, field_data); } void ima_show_template_sig(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data) { ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data); } void ima_show_template_buf(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data) { ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data); } void ima_show_template_uint(struct seq_file *m, enum ima_show_type show, struct ima_field_data *field_data) { ima_show_template_field_data(m, show, DATA_FMT_UINT, field_data); } /** * ima_parse_buf() - Parses lengths and data from an input buffer * @bufstartp: Buffer start address. * @bufendp: Buffer end address. * @bufcurp: Pointer to remaining (non-parsed) data. * @maxfields: Length of fields array. * @fields: Array containing lengths and pointers of parsed data. * @curfields: Number of array items containing parsed data. * @len_mask: Bitmap (if bit is set, data length should not be parsed). * @enforce_mask: Check if curfields == maxfields and/or bufcurp == bufendp. * @bufname: String identifier of the input buffer. * * Return: 0 on success, -EINVAL on error. */ int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp, int maxfields, struct ima_field_data *fields, int *curfields, unsigned long *len_mask, int enforce_mask, char *bufname) { void *bufp = bufstartp; int i; for (i = 0; i < maxfields; i++) { if (len_mask == NULL || !test_bit(i, len_mask)) { if (bufp > (bufendp - sizeof(u32))) break; if (ima_canonical_fmt) fields[i].len = le32_to_cpu(*(__le32 *)bufp); else fields[i].len = *(u32 *)bufp; bufp += sizeof(u32); } if (bufp > (bufendp - fields[i].len)) break; fields[i].data = bufp; bufp += fields[i].len; } if ((enforce_mask & ENFORCE_FIELDS) && i != maxfields) { pr_err("%s: nr of fields mismatch: expected: %d, current: %d\n", bufname, maxfields, i); return -EINVAL; } if ((enforce_mask & ENFORCE_BUFEND) && bufp != bufendp) { pr_err("%s: buf end mismatch: expected: %p, current: %p\n", bufname, bufendp, bufp); return -EINVAL; } if (curfields) *curfields = i; if (bufcurp) *bufcurp = bufp; return 0; } static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize, u8 digest_type, u8 hash_algo, struct ima_field_data *field_data) { /* * digest formats: * - DATA_FMT_DIGEST: digest * - DATA_FMT_DIGEST_WITH_ALGO: <hash algo> + ':' + '\0' + digest, * - DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO: * <digest type> + ':' + <hash algo> + ':' + '\0' + digest, * * where 'DATA_FMT_DIGEST' is the original digest format ('d') * with a hash size limitation of 20 bytes, * where <digest type> is either "ima" or "verity", * where <hash algo> is the hash_algo_name[] string. */ u8 buffer[DIGEST_TYPE_NAME_LEN_MAX + CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 }; enum data_formats fmt = DATA_FMT_DIGEST; u32 offset = 0; if (digest_type < DIGEST_TYPE__LAST && hash_algo < HASH_ALGO__LAST) { fmt = DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO; offset += 1 + sprintf(buffer, "%s:%s:", digest_type_name[digest_type], hash_algo_name[hash_algo]); } else if (hash_algo < HASH_ALGO__LAST) { fmt = DATA_FMT_DIGEST_WITH_ALGO; offset += 1 + sprintf(buffer, "%s:", hash_algo_name[hash_algo]); } if (digest) memcpy(buffer + offset, digest, digestsize); else /* * If digest is NULL, the event being recorded is a violation. * Make room for the digest by increasing the offset by the * hash algorithm digest size. */ offset += hash_digest_size[hash_algo]; return ima_write_template_field_data(buffer, offset + digestsize, fmt, field_data); } /* * This function writes the digest of an event (with size limit). */ int ima_eventdigest_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { struct ima_max_digest_data hash; u8 *cur_digest = NULL; u32 cur_digestsize = 0; struct inode *inode; int result; memset(&hash, 0, sizeof(hash)); if (event_data->violation) /* recording a violation. */ goto out; if (ima_template_hash_algo_allowed(event_data->iint->ima_hash->algo)) { cur_digest = event_data->iint->ima_hash->digest; cur_digestsize = event_data->iint->ima_hash->length; goto out; } if ((const char *)event_data->filename == boot_aggregate_name) { if (ima_tpm_chip) { hash.hdr.algo = HASH_ALGO_SHA1; result = ima_calc_boot_aggregate(&hash.hdr); /* algo can change depending on available PCR banks */ if (!result && hash.hdr.algo != HASH_ALGO_SHA1) result = -EINVAL; if (result < 0) memset(&hash, 0, sizeof(hash)); } cur_digest = hash.hdr.digest; cur_digestsize = hash_digest_size[HASH_ALGO_SHA1]; goto out; } if (!event_data->file) /* missing info to re-calculate the digest */ return -EINVAL; inode = file_inode(event_data->file); hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ? ima_hash_algo : HASH_ALGO_SHA1; result = ima_calc_file_hash(event_data->file, &hash.hdr); if (result) { integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, event_data->filename, "collect_data", "failed", result, 0); return result; } cur_digest = hash.hdr.digest; cur_digestsize = hash.hdr.length; out: return ima_eventdigest_init_common(cur_digest, cur_digestsize, DIGEST_TYPE__LAST, HASH_ALGO__LAST, field_data); } /* * This function writes the digest of an event (without size limit). */ int ima_eventdigest_ng_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { u8 *cur_digest = NULL, hash_algo = ima_hash_algo; u32 cur_digestsize = 0; if (event_data->violation) /* recording a violation. */ goto out; cur_digest = event_data->iint->ima_hash->digest; cur_digestsize = event_data->iint->ima_hash->length; hash_algo = event_data->iint->ima_hash->algo; out: return ima_eventdigest_init_common(cur_digest, cur_digestsize, DIGEST_TYPE__LAST, hash_algo, field_data); } /* * This function writes the digest of an event (without size limit), * prefixed with both the digest type and hash algorithm. */ int ima_eventdigest_ngv2_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { u8 *cur_digest = NULL, hash_algo = ima_hash_algo; u32 cur_digestsize = 0; u8 digest_type = DIGEST_TYPE_IMA; if (event_data->violation) /* recording a violation. */ goto out; cur_digest = event_data->iint->ima_hash->digest; cur_digestsize = event_data->iint->ima_hash->length; hash_algo = event_data->iint->ima_hash->algo; if (event_data->iint->flags & IMA_VERITY_REQUIRED) digest_type = DIGEST_TYPE_VERITY; out: return ima_eventdigest_init_common(cur_digest, cur_digestsize, digest_type, hash_algo, field_data); } /* * This function writes the digest of the file which is expected to match the * digest contained in the file's appended signature. */ int ima_eventdigest_modsig_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { enum hash_algo hash_algo; const u8 *cur_digest; u32 cur_digestsize; if (!event_data->modsig) return 0; if (event_data->violation) { /* Recording a violation. */ hash_algo = HASH_ALGO_SHA1; cur_digest = NULL; cur_digestsize = 0; } else { int rc; rc = ima_get_modsig_digest(event_data->modsig, &hash_algo, &cur_digest, &cur_digestsize); if (rc) return rc; else if (hash_algo == HASH_ALGO__LAST || cur_digestsize == 0) /* There was some error collecting the digest. */ return -EINVAL; } return ima_eventdigest_init_common(cur_digest, cur_digestsize, DIGEST_TYPE__LAST, hash_algo, field_data); } static int ima_eventname_init_common(struct ima_event_data *event_data, struct ima_field_data *field_data, bool size_limit) { const char *cur_filename = NULL; u32 cur_filename_len = 0; BUG_ON(event_data->filename == NULL && event_data->file == NULL); if (event_data->filename) { cur_filename = event_data->filename; cur_filename_len = strlen(event_data->filename); if (!size_limit || cur_filename_len <= IMA_EVENT_NAME_LEN_MAX) goto out; } if (event_data->file) { cur_filename = event_data->file->f_path.dentry->d_name.name; cur_filename_len = strlen(cur_filename); } else /* * Truncate filename if the latter is too long and * the file descriptor is not available. */ cur_filename_len = IMA_EVENT_NAME_LEN_MAX; out: return ima_write_template_field_data(cur_filename, cur_filename_len, DATA_FMT_STRING, field_data); } /* * This function writes the name of an event (with size limit). */ int ima_eventname_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { return ima_eventname_init_common(event_data, field_data, true); } /* * This function writes the name of an event (without size limit). */ int ima_eventname_ng_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { return ima_eventname_init_common(event_data, field_data, false); } /* * ima_eventsig_init - include the file signature as part of the template data */ int ima_eventsig_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { struct evm_ima_xattr_data *xattr_value = event_data->xattr_value; if (!xattr_value || (xattr_value->type != EVM_IMA_XATTR_DIGSIG && xattr_value->type != IMA_VERITY_DIGSIG)) return ima_eventevmsig_init(event_data, field_data); return ima_write_template_field_data(xattr_value, event_data->xattr_len, DATA_FMT_HEX, field_data); } /* * ima_eventbuf_init - include the buffer(kexec-cmldine) as part of the * template data. */ int ima_eventbuf_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { if ((!event_data->buf) || (event_data->buf_len == 0)) return 0; return ima_write_template_field_data(event_data->buf, event_data->buf_len, DATA_FMT_HEX, field_data); } /* * ima_eventmodsig_init - include the appended file signature as part of the * template data */ int ima_eventmodsig_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { const void *data; u32 data_len; int rc; if (!event_data->modsig) return 0; /* * modsig is a runtime structure containing pointers. Get its raw data * instead. */ rc = ima_get_raw_modsig(event_data->modsig, &data, &data_len); if (rc) return rc; return ima_write_template_field_data(data, data_len, DATA_FMT_HEX, field_data); } /* * ima_eventevmsig_init - include the EVM portable signature as part of the * template data */ int ima_eventevmsig_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { struct evm_ima_xattr_data *xattr_data = NULL; int rc = 0; if (!event_data->file) return 0; rc = vfs_getxattr_alloc(&init_user_ns, file_dentry(event_data->file), XATTR_NAME_EVM, (char **)&xattr_data, 0, GFP_NOFS); if (rc <= 0) return 0; if (xattr_data->type != EVM_XATTR_PORTABLE_DIGSIG) { kfree(xattr_data); return 0; } rc = ima_write_template_field_data((char *)xattr_data, rc, DATA_FMT_HEX, field_data); kfree(xattr_data); return rc; } static int ima_eventinodedac_init_common(struct ima_event_data *event_data, struct ima_field_data *field_data, bool get_uid) { unsigned int id; if (!event_data->file) return 0; if (get_uid) id = i_uid_read(file_inode(event_data->file)); else id = i_gid_read(file_inode(event_data->file)); if (ima_canonical_fmt) { if (sizeof(id) == sizeof(u16)) id = (__force u16)cpu_to_le16(id); else id = (__force u32)cpu_to_le32(id); } return ima_write_template_field_data((void *)&id, sizeof(id), DATA_FMT_UINT, field_data); } /* * ima_eventinodeuid_init - include the inode UID as part of the template * data */ int ima_eventinodeuid_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { return ima_eventinodedac_init_common(event_data, field_data, true); } /* * ima_eventinodegid_init - include the inode GID as part of the template * data */ int ima_eventinodegid_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { return ima_eventinodedac_init_common(event_data, field_data, false); } /* * ima_eventinodemode_init - include the inode mode as part of the template * data */ int ima_eventinodemode_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { struct inode *inode; u16 mode; if (!event_data->file) return 0; inode = file_inode(event_data->file); mode = inode->i_mode; if (ima_canonical_fmt) mode = (__force u16)cpu_to_le16(mode); return ima_write_template_field_data((char *)&mode, sizeof(mode), DATA_FMT_UINT, field_data); } static int ima_eventinodexattrs_init_common(struct ima_event_data *event_data, struct ima_field_data *field_data, char type) { u8 *buffer = NULL; int rc; if (!event_data->file) return 0; rc = evm_read_protected_xattrs(file_dentry(event_data->file), NULL, 0, type, ima_canonical_fmt); if (rc < 0) return 0; buffer = kmalloc(rc, GFP_KERNEL); if (!buffer) return 0; rc = evm_read_protected_xattrs(file_dentry(event_data->file), buffer, rc, type, ima_canonical_fmt); if (rc < 0) { rc = 0; goto out; } rc = ima_write_template_field_data((char *)buffer, rc, DATA_FMT_HEX, field_data); out: kfree(buffer); return rc; } /* * ima_eventinodexattrnames_init - include a list of xattr names as part of the * template data */ int ima_eventinodexattrnames_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { return ima_eventinodexattrs_init_common(event_data, field_data, 'n'); } /* * ima_eventinodexattrlengths_init - include a list of xattr lengths as part of * the template data */ int ima_eventinodexattrlengths_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { return ima_eventinodexattrs_init_common(event_data, field_data, 'l'); } /* * ima_eventinodexattrvalues_init - include a list of xattr values as part of * the template data */ int ima_eventinodexattrvalues_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { return ima_eventinodexattrs_init_common(event_data, field_data, 'v'); } |