/* * ks.h * ---- * Keystore, generic parts anyway. This is internal within libhal. * * Copyright (c) 2015-2017, NORDUnet A/S All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * - Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of the NORDUnet nor the names of its contributors may * be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef _KS_H_ #define _KS_H_ #include "hal.h" #include "hal_internal.h" /* * Size of a keystore "block". * * This must be an integer multiple of the flash subsector size, among * other reasons because that's the minimum erasable unit. */ #ifndef HAL_KS_BLOCK_SIZE #define HAL_KS_BLOCK_SIZE (4096 * 2) #endif #if HAL_KS_WRAPPED_KEYSIZE + 8 > HAL_KS_BLOCK_SIZE #warning HAL_KS_WRAPPED_KEYSIZE is too big for to fit in a keystore block #endif /* * PIN block gets the all-zeros UUID, which will never be returned by * the UUID generation code (by definition -- it's not a version 4 UUID). */ const hal_uuid_t hal_ks_pin_uuid; /* * Known block states. * * C does not guarantee any particular representation for enums, so * including enums directly in the block header isn't safe. Instead, * we use an access method which casts when reading from the header. * Writing to the header isn't a problem, because C does guarantee * that enum is compatible with *some* integer type, it just doesn't * specify which one. */ typedef enum { HAL_KS_BLOCK_TYPE_ERASED = 0xFF, /* Pristine erased block (candidate for reuse) */ HAL_KS_BLOCK_TYPE_ZEROED = 0x00, /* Zeroed block (recently used) */ HAL_KS_BLOCK_TYPE_KEY = 0x55, /* Block contains key material */ HAL_KS_BLOCK_TYPE_PIN = 0xAA, /* Block contains PINs */ HAL_KS_BLOCK_TYPE_UNKNOWN = -1, /* Internal code for "I have no clue what this is" */ } hal_ks_block_type_t; /* * Block status. */ typedef enum { HAL_KS_BLOCK_STATUS_LIVE = 0x66, /* This is a live block */ HAL_KS_BLOCK_STATUS_TOMBSTONE = 0x44, /* This is a tombstone left behind during an update */ HAL_KS_BLOCK_STATUS_UNKNOWN = -1, /* Internal code for "I have no clue what this is" */ } hal_ks_block_status_t; /* * Common header for all keystore block types. A few of these fields * are deliberately omitted from the CRC. * * The legacy_1 and legacy_2 fields were used in the more complex * "chunked" layout used in an earlier iteration of this keystore * design, which proved more complex than it was worth. At the * moment, the only thing we do with these fields is include them in * the CRC and check them for allowed values, to avoid gratuitously * breaking backwards compatability with the earlier design. */ typedef struct { uint8_t block_type; uint8_t block_status; uint8_t legacy_1; uint8_t legacy_2; hal_crc32_t crc; } hal_ks_block_header_t; /* * Key block. Tail end of "der" field (after der_len) used for attributes. */ typedef struct { hal_ks_block_header_t header; hal_uuid_t name; hal_key_type_t type; hal_curve_name_t curve; hal_key_flags_t flags; size_t der_len; unsigned attributes_len; uint8_t der[]; /* Must be last field -- C99 "flexible array member" */ } hal_ks_key_block_t; #define SIZEOF_KS_KEY_BLOCK_DER \ (HAL_KS_BLOCK_SIZE - offsetof(hal_ks_key_block_t, der)) /* * PIN block. Also includes space for backing up the KEK when * HAL_MKM_FLASH_BACKUP_KLUDGE is enabled. */ typedef struct { hal_ks_block_header_t header; hal_ks_pin_t wheel_pin; hal_ks_pin_t so_pin; hal_ks_pin_t user_pin; #if HAL_MKM_FLASH_BACKUP_KLUDGE uint32_t kek_set; uint8_t kek[KEK_LENGTH]; #endif } hal_ks_pin_block_t; #define FLASH_KEK_NOT_SET 0 #define FLASH_KEK_SET 0x33333333 /* * One keystore block. */ typedef union { uint8_t bytes[HAL_KS_BLOCK_SIZE]; hal_ks_block_header_t header; hal_ks_key_block_t key; hal_ks_pin_block_t pin; } hal_ks_block_t; /* * In-memory cache. */ typedef struct { unsigned blockno; unsigned lru; hal_ks_block_t block; } hal_ks_cache_block_t; /* * Keystore object. hal_internal.h typedefs this to hal_ks_t. * * We expect this to be a static variable, but we expect the arrays in * it to be allocated at runtime using hal_allocate_static_memory() * because they can get kind of large. * * Driver-specific stuff is handled by a form of subclassing: the * driver embeds the hal_ks_t structure at the head of whatever else * it needs, and performs (controlled, type-safe) casts as needed. * * Core of this is the keystore index. This is intended to be usable * by both memory-based and flash-based keystores. Some of the * features aren't necessary for memory-based keystores, but should be * harmless, and let us keep the drivers simple. * * General approach is multiple arrays, all but one of which are * indexed by "block" numbers, where a block number might be a slot in * yet another static array, the number of a flash sub-sector, or * whatever is the appropriate unit for holding one keystore record. * * The index array only contains block numbers. This is a small data * structure so that moving data within it is relatively cheap. * * The index array is divided into two portions: the index proper, and * the free queue. The index proper is ordered according to the names * (UUIDs) of the corresponding blocks; the free queue is a FIFO, to * support a simplistic form of wear leveling in flash-based keystores. * * Key names are kept in a separate array, indexed by block number. * * The all-zeros UUID, which (by definition) cannot be a valid key * UUID, is reserved for the (non-key) block used to stash PINs and * other small data which aren't really part of the keystore proper * but are kept with it because the keystore is the flash we have. * * Note that this API deliberately says nothing about how the keys * themselves are stored, that's up to the keystore driver. */ typedef struct hal_ks_driver hal_ks_driver_t; struct hal_ks { const hal_ks_driver_t *driver;/* Must be first */ unsigned size; /* Blocks in keystore */ unsigned used; /* How many blocks are in use */ uint16_t *index; /* Index/freelist array */ hal_uuid_t *names; /* Keyname array */ unsigned cache_lru; /* Cache LRU counter */ unsigned cache_size; /* Size (how many blocks) in cache */ hal_ks_cache_block_t *cache; /* Cache */ }; /* * Keystore driver. */ struct hal_ks_driver { hal_error_t (*init) (hal_ks_t *ks, const int alloc); hal_error_t (*read) (hal_ks_t *ks, const unsigned blockno, hal_ks_block_t *block); hal_error_t (*write) (hal_ks_t *ks, const unsigned blockno, hal_ks_block_t *block); hal_error_t (*deprecate) (hal_ks_t *ks, const unsigned blockno); hal_error_t (*zero) (hal_ks_t *ks, const unsigned blockno); hal_error_t (*erase) (hal_ks_t *ks, const unsigned blockno); hal_error_t (*erase_maybe) (hal_ks_t *ks, const unsigned blockno); hal_error_t (*set_owner) (hal_ks_t *ks, const unsigned blockno, const hal_client_handle_t client, const hal_session_handle_t session); hal_error_t (*test_owner) (hal_ks_t *ks, const unsigned blockno, const hal_client_handle_t client, const hal_session_handle_t session); hal_error_t (*copy_owner) (hal_ks_t *ks, const unsigned source, const unsigned target); hal_error_t (*logout) (hal_ks_t *ks, const hal_client_handle_t client); }; /* * Wrappers around keystore driver methods. * * hal_ks_init() and hal_ks_logout() are missing here because we * expose them to the rest of libhal. */ static inline hal_error_t hal_ks_block_read(hal_ks_t *ks, const unsigned blockno, hal_ks_block_t *block) { return ks == NULL || ks->driver == NULL ? HAL_ERROR_BAD_ARGUMENTS : ks->driver->read == NULL ? HAL_ERROR_NOT_IMPLEMENTED : ks->driver->read(ks, blockno, block); } static inline hal_error_t hal_ks_block_write(hal_ks_t *ks, const unsigned blockno, hal_ks_block_t *block) { return ks == NULL || ks->driver == NULL ? HAL_ERROR_BAD_ARGUMENTS : ks->driver->write == NULL ? HAL_ERROR_NOT_IMPLEMENTED : ks->driver->write(ks, blockno, block); } static inline hal_error_t hal_ks_block_deprecate(hal_ks_t *ks, const unsigned blockno) { return ks == NULL || ks->driver == NULL ? HAL_ERROR_BAD_ARGUMENTS : ks->driver->deprecate == NULL ? HAL_ERROR_NOT_IMPLEMENTED : ks->driver->deprecate(ks, blockno); } static inline hal_error_t hal_ks_block_zero(hal_ks_t *ks, const unsigned blockno) { return ks == NULL || ks->driver == NULL ? HAL_ERROR_BAD_ARGUMENTS : ks->driver->zero == NULL ? HAL_ERROR_NOT_IMPLEMENTED : ks->driver->zero(ks, blockno); } static inline hal_error_t hal_ks_block_erase(hal_ks_t *ks, const unsigned blockno) { return ks == NULL || ks->driver == NULL ? HAL_ERROR_BAD_ARGUMENTS : ks->driver->erase == NULL ? HAL_ERROR_NOT_IMPLEMENTED : ks->driver->erase(ks, blockno); } static inline hal_error_t hal_ks_block_erase_maybe(hal_ks_t *ks, const unsigned blockno) { return ks == NULL || ks->driver == NULL ? HAL_ERROR_BAD_ARGUMENTS : ks->driver->erase_maybe == NULL ? HAL_ERROR_NOT_IMPLEMENTED : ks->driver->erase_maybe(ks, blockno); } static inline hal_error_t hal_ks_block_set_owner(hal_ks_t *ks, const unsigned blockno, const hal_client_handle_t client, const hal_session_handle_t session) { return ks == NULL || ks->driver == NULL ? HAL_ERROR_BAD_ARGUMENTS : ks->driver->set_owner == NULL ? HAL_ERROR_NOT_IMPLEMENTED : ks->driver->set_owner(ks, blockno, client, session); } static inline hal_error_t hal_ks_block_test_owner(hal_ks_t *ks, const unsigned blockno, const hal_client_handle_t client, const hal_session_handle_t session) { return ks == NULL || ks->driver == NULL ? HAL_ERROR_BAD_ARGUMENTS : ks->driver->test_owner == NULL ? HAL_ERROR_NOT_IMPLEMENTED : ks->driver->test_owner(ks, blockno, client, session); } static inline hal_error_t hal_ks_block_copy_owner(hal_ks_t *ks, const unsigned source, const unsigned target) { return ks == NULL || ks->driver == NULL ? HAL_ERROR_BAD_ARGUMENTS : ks->driver->copy_owner == NULL ? HAL_ERROR_NOT_IMPLEMENTED : ks->driver->copy_owner(ks, source, target); } /* * Type safe casts. */ static inline hal_ks_block_type_t hal_ks_block_get_type(const hal_ks_block_t * const block) { return block == NULL ? HAL_KS_BLOCK_TYPE_UNKNOWN : (hal_ks_block_type_t) block->header.block_type; } static inline hal_ks_block_status_t hal_ks_block_get_status(const hal_ks_block_t * const block) { return block == NULL ? HAL_KS_BLOCK_STATUS_UNKNOWN : (hal_ks_block_status_t) block->header.block_status; } /* * Keystore utilities. Some or all of these may end up static within ks.c. */ extern hal_error_t hal_ks_alloc_common(hal_ks_t *ks, const unsigned ks_blocks, const unsigned cache_blocks, void **extra, const size_t extra_len); extern hal_error_t hal_ks_init_common(hal_ks_t *ks); extern hal_crc32_t hal_ks_block_calculate_crc(const hal_ks_block_t * const block); extern hal_error_t hal_ks_index_heapsort(hal_ks_t *ks); extern hal_error_t hal_ks_index_find(hal_ks_t *ks, const hal_uuid_t * const name, unsigned *blockno, int *hint); extern hal_error_t hal_ks_index_add(hal_ks_t *ks, const hal_uuid_t * const name, unsigned *blockno, int *hint); extern hal_error_t hal_ks_index_delete(hal_ks_t *ks, const hal_uuid_t * const name, unsigned *blockno, int *hint); extern hal_error_t hal_ks_index_replace(hal_ks_t *ks, const hal_uuid_t * const name, unsigned *blockno, int *hint); extern hal_error_t hal_ks_index_fsck(hal_ks_t *ks); extern const size_t hal_ks_attribute_header_size; extern hal_error_t hal_ks_attribute_scan(const uint8_t * const bytes, const size_t bytes_len, hal_pkey_attribute_t *attributes, const unsigned attributes_len, size_t *total_len); extern hal_error_t hal_ks_attribute_delete(uint8_t *bytes, const size_t bytes_len, hal_pkey_attribute_t *attributes, unsigned *attributes_len, size_t *total_len, const uint32_t type); extern hal_error_t hal_ks_attribute_insert(uint8_t *bytes, const size_t bytes_len, hal_pkey_attribute_t *attributes, unsigned *attributes_len, size_t *total_len, const uint32_t type, const uint8_t * const value, const size_t value_len); extern hal_ks_block_t *hal_ks_cache_pick_lru(hal_ks_t *ks); extern hal_ks_block_t *hal_ks_cache_find_block(const hal_ks_t * const ks, const unsigned blockno); extern void hal_ks_cache_mark_used(hal_ks_t *ks, const hal_ks_block_t * const block, const unsigned blockno); extern void hal_ks_cache_release(hal_ks_t *ks, const hal_ks_block_t * const block); extern hal_error_t hal_ks_block_read_cached(hal_ks_t *ks, const unsigned blockno, hal_ks_block_t **block); extern hal_error_t hal_ks_block_update(hal_ks_t *ks, const unsigned b1, hal_ks_block_t *block, const hal_uuid_t * const uuid, int *hint); #endif /* _KS_H_ */ /* * Local variables: * indent-tabs-mode: nil * End: */ n415'>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 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