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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /fs/verity/hash_algs.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'fs/verity/hash_algs.c')
| -rw-r--r-- | fs/verity/hash_algs.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/fs/verity/hash_algs.c b/fs/verity/hash_algs.c new file mode 100644 index 000000000..de53e14c8 --- /dev/null +++ b/fs/verity/hash_algs.c @@ -0,0 +1,188 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * fs-verity hash algorithms + * + * Copyright 2019 Google LLC + */ + +#include "fsverity_private.h" + +/* The hash algorithms supported by fs-verity */ +const struct fsverity_hash_alg fsverity_hash_algs[] = { + [FS_VERITY_HASH_ALG_SHA256] = { + .name = "sha256", + .digest_size = SHA256_DIGEST_SIZE, + .block_size = SHA256_BLOCK_SIZE, + .algo_id = HASH_ALGO_SHA256, + }, + [FS_VERITY_HASH_ALG_SHA512] = { + .name = "sha512", + .digest_size = SHA512_DIGEST_SIZE, + .block_size = SHA512_BLOCK_SIZE, + .algo_id = HASH_ALGO_SHA512, + }, +}; + +/** + * fsverity_get_hash_alg() - get a hash algorithm by number + * @inode: optional inode for logging purposes + * @num: the hash algorithm number + * + * Get the struct fsverity_hash_alg for the given hash algorithm number. + * + * Return: pointer to the hash alg if it's known, otherwise NULL. + */ +const struct fsverity_hash_alg *fsverity_get_hash_alg(const struct inode *inode, + unsigned int num) +{ + if (num >= ARRAY_SIZE(fsverity_hash_algs) || + !fsverity_hash_algs[num].name) { + fsverity_warn(inode, "Unknown hash algorithm number: %u", num); + return NULL; + } + return &fsverity_hash_algs[num]; +} + +/** + * fsverity_prepare_hash_state() - precompute the initial hash state + * @alg: hash algorithm + * @salt: a salt which is to be prepended to all data to be hashed + * @salt_size: salt size in bytes + * + * Return: the kmalloc()'ed initial hash state, or NULL if out of memory. + */ +union fsverity_hash_ctx * +fsverity_prepare_hash_state(const struct fsverity_hash_alg *alg, + const u8 *salt, size_t salt_size) +{ + u8 *padded_salt = NULL; + size_t padded_salt_size; + union fsverity_hash_ctx ctx; + void *res = NULL; + + /* + * Zero-pad the salt to the next multiple of the input size of the hash + * algorithm's compression function, e.g. 64 bytes for SHA-256 or 128 + * bytes for SHA-512. This ensures that the hash algorithm won't have + * any bytes buffered internally after processing the salt, thus making + * salted hashing just as fast as unsalted hashing. + */ + padded_salt_size = round_up(salt_size, alg->block_size); + padded_salt = kzalloc(padded_salt_size, GFP_KERNEL); + if (!padded_salt) + return NULL; + memcpy(padded_salt, salt, salt_size); + + switch (alg->algo_id) { + case HASH_ALGO_SHA256: + sha256_init(&ctx.sha256); + sha256_update(&ctx.sha256, padded_salt, padded_salt_size); + res = kmemdup(&ctx.sha256, sizeof(ctx.sha256), GFP_KERNEL); + break; + case HASH_ALGO_SHA512: + sha512_init(&ctx.sha512); + sha512_update(&ctx.sha512, padded_salt, padded_salt_size); + res = kmemdup(&ctx.sha512, sizeof(ctx.sha512), GFP_KERNEL); + break; + default: + WARN_ON_ONCE(1); + } + kfree(padded_salt); + return res; +} + +/** + * fsverity_hash_block() - hash a single data or hash block + * @params: the Merkle tree's parameters + * @data: virtual address of a buffer containing the block to hash + * @out: output digest, size 'params->digest_size' bytes + * + * Hash a single data or hash block. The hash is salted if a salt is specified + * in the Merkle tree parameters. + */ +void fsverity_hash_block(const struct merkle_tree_params *params, + const void *data, u8 *out) +{ + union fsverity_hash_ctx ctx; + + if (!params->hashstate) { + fsverity_hash_buffer(params->hash_alg, data, params->block_size, + out); + return; + } + + switch (params->hash_alg->algo_id) { + case HASH_ALGO_SHA256: + ctx.sha256 = params->hashstate->sha256; + sha256_update(&ctx.sha256, data, params->block_size); + sha256_final(&ctx.sha256, out); + return; + case HASH_ALGO_SHA512: + ctx.sha512 = params->hashstate->sha512; + sha512_update(&ctx.sha512, data, params->block_size); + sha512_final(&ctx.sha512, out); + return; + default: + BUG(); + } +} + +/** + * fsverity_hash_buffer() - hash some data + * @alg: the hash algorithm to use + * @data: the data to hash + * @size: size of data to hash, in bytes + * @out: output digest, size 'alg->digest_size' bytes + */ +void fsverity_hash_buffer(const struct fsverity_hash_alg *alg, + const void *data, size_t size, u8 *out) +{ + switch (alg->algo_id) { + case HASH_ALGO_SHA256: + sha256(data, size, out); + return; + case HASH_ALGO_SHA512: + sha512(data, size, out); + return; + default: + BUG(); + } +} + +void __init fsverity_check_hash_algs(void) +{ + size_t i; + + /* + * Sanity check the hash algorithms (could be a build-time check, but + * they're in an array) + */ + for (i = 0; i < ARRAY_SIZE(fsverity_hash_algs); i++) { + const struct fsverity_hash_alg *alg = &fsverity_hash_algs[i]; + + if (!alg->name) + continue; + + /* + * 0 must never be allocated as an FS_VERITY_HASH_ALG_* value, + * as it is reserved for users that use 0 to mean unspecified or + * a default value. fs/verity/ itself doesn't care and doesn't + * have a default algorithm, but some users make use of this. + */ + BUG_ON(i == 0); + + BUG_ON(alg->digest_size > FS_VERITY_MAX_DIGEST_SIZE); + + /* + * For efficiency, the implementation currently assumes the + * digest and block sizes are powers of 2. This limitation can + * be lifted if the code is updated to handle other values. + */ + BUG_ON(!is_power_of_2(alg->digest_size)); + BUG_ON(!is_power_of_2(alg->block_size)); + + /* Verify that there is a valid mapping to HASH_ALGO_*. */ + BUG_ON(alg->algo_id == 0); + BUG_ON(alg->digest_size != hash_digest_size[alg->algo_id]); + } +} |
