^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /* SPDX-License-Identifier: GPL-2.0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * fs-verity: read-only file-based authenticity protection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright 2019 Google LLC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #ifndef _FSVERITY_PRIVATE_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #define _FSVERITY_PRIVATE_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #ifdef CONFIG_FS_VERITY_DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #define DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #define pr_fmt(fmt) "fs-verity: " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <crypto/sha.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/fsverity.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/mempool.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) struct ahash_request;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * Implementation limit: maximum depth of the Merkle tree. For now 8 is plenty;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * it's enough for over U64_MAX bytes of data using SHA-256 and 4K blocks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #define FS_VERITY_MAX_LEVELS 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * Largest digest size among all hash algorithms supported by fs-verity.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * Currently assumed to be <= size of fsverity_descriptor::root_hash.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #define FS_VERITY_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) /* A hash algorithm supported by fs-verity */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) struct fsverity_hash_alg {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) struct crypto_ahash *tfm; /* hash tfm, allocated on demand */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) const char *name; /* crypto API name, e.g. sha256 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) unsigned int digest_size; /* digest size in bytes, e.g. 32 for SHA-256 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) unsigned int block_size; /* block size in bytes, e.g. 64 for SHA-256 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) mempool_t req_pool; /* mempool with a preallocated hash request */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) /* Merkle tree parameters: hash algorithm, initial hash state, and topology */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) struct merkle_tree_params {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) struct fsverity_hash_alg *hash_alg; /* the hash algorithm */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) const u8 *hashstate; /* initial hash state or NULL */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) unsigned int digest_size; /* same as hash_alg->digest_size */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) unsigned int block_size; /* size of data and tree blocks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) unsigned int hashes_per_block; /* number of hashes per tree block */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) unsigned int log_blocksize; /* log2(block_size) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) unsigned int log_arity; /* log2(hashes_per_block) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) unsigned int num_levels; /* number of levels in Merkle tree */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) u64 tree_size; /* Merkle tree size in bytes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) unsigned long level0_blocks; /* number of blocks in tree level 0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * Starting block index for each tree level, ordered from leaf level (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * to root level ('num_levels - 1')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) u64 level_start[FS_VERITY_MAX_LEVELS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) * fsverity_info - cached verity metadata for an inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) * When a verity file is first opened, an instance of this struct is allocated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * and stored in ->i_verity_info; it remains until the inode is evicted. It
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * caches information about the Merkle tree that's needed to efficiently verify
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * data read from the file. It also caches the file digest. The Merkle tree
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) * pages themselves are not cached here, but the filesystem may cache them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) struct fsverity_info {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) struct merkle_tree_params tree_params;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) u8 root_hash[FS_VERITY_MAX_DIGEST_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) u8 file_digest[FS_VERITY_MAX_DIGEST_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) const struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) /* Arbitrary limit to bound the kmalloc() size. Can be changed. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) #define FS_VERITY_MAX_DESCRIPTOR_SIZE 16384
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) #define FS_VERITY_MAX_SIGNATURE_SIZE (FS_VERITY_MAX_DESCRIPTOR_SIZE - \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) sizeof(struct fsverity_descriptor))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) /* hash_algs.c */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) extern struct fsverity_hash_alg fsverity_hash_algs[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) struct fsverity_hash_alg *fsverity_get_hash_alg(const struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) unsigned int num);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) struct ahash_request *fsverity_alloc_hash_request(struct fsverity_hash_alg *alg,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) gfp_t gfp_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) void fsverity_free_hash_request(struct fsverity_hash_alg *alg,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) struct ahash_request *req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) const u8 *salt, size_t salt_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) int fsverity_hash_page(const struct merkle_tree_params *params,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) const struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) struct ahash_request *req, struct page *page, u8 *out);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) int fsverity_hash_buffer(struct fsverity_hash_alg *alg,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) const void *data, size_t size, u8 *out);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) void __init fsverity_check_hash_algs(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) /* init.c */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) void __printf(3, 4) __cold
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) fsverity_msg(const struct inode *inode, const char *level,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) const char *fmt, ...);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) #define fsverity_warn(inode, fmt, ...) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) fsverity_msg((inode), KERN_WARNING, fmt, ##__VA_ARGS__)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) #define fsverity_err(inode, fmt, ...) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) fsverity_msg((inode), KERN_ERR, fmt, ##__VA_ARGS__)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) /* open.c */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) int fsverity_init_merkle_tree_params(struct merkle_tree_params *params,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) const struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) unsigned int hash_algorithm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) unsigned int log_blocksize,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) const u8 *salt, size_t salt_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) struct fsverity_info *fsverity_create_info(const struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) struct fsverity_descriptor *desc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) size_t desc_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) void fsverity_set_info(struct inode *inode, struct fsverity_info *vi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) void fsverity_free_info(struct fsverity_info *vi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) int fsverity_get_descriptor(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) struct fsverity_descriptor **desc_ret,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) size_t *desc_size_ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) int __init fsverity_init_info_cache(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) void __init fsverity_exit_info_cache(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) /* signature.c */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) #ifdef CONFIG_FS_VERITY_BUILTIN_SIGNATURES
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) int fsverity_verify_signature(const struct fsverity_info *vi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) const u8 *signature, size_t sig_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) int __init fsverity_init_signature(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) #else /* !CONFIG_FS_VERITY_BUILTIN_SIGNATURES */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) static inline int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) fsverity_verify_signature(const struct fsverity_info *vi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) const u8 *signature, size_t sig_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) static inline int fsverity_init_signature(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) #endif /* !CONFIG_FS_VERITY_BUILTIN_SIGNATURES */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) /* verify.c */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) int __init fsverity_init_workqueue(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) void __init fsverity_exit_workqueue(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) #endif /* _FSVERITY_PRIVATE_H */
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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