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| author | Eric Biggers <ebiggers@kernel.org> | 2026-07-12 22:36:54 -0400 |
|---|---|---|
| committer | Eric Biggers <ebiggers@kernel.org> | 2026-07-20 10:39:25 -0700 |
| commit | 95b39df0413077b631cde9c6e35224c15258ccf5 (patch) | |
| tree | f22f8bc4cb8e5a12497642f46eb4080ea193a078 /block | |
| parent | 0ffa0da2e538f5edd215384fd86a734cb356af22 (diff) | |
| download | lwn-95b39df0413077b631cde9c6e35224c15258ccf5.tar.gz lwn-95b39df0413077b631cde9c6e35224c15258ccf5.zip | |
blk-crypto: Allow control over whether hardware is used
fscrypt uses inline encryption hardware only when the "inlinecrypt"
mount option is given. I'd like to keep that behavior even after
standardizing on the blk-crypto API for file contents encryption. That
is, the default should continue to be the well-tested CPU-based
encryption code, and the use of inline encryption hardware should
continue to be an opt-in feature for systems where it's beneficial and
has been fully validated (including verifying ciphertext correctness).
To support this use case, extend blk_crypto_config with a new flag
BLK_CRYPTO_CFG_ALLOW_HW.
For now it's always set. Later commits will change that.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260713023708.9245-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-crypto.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/block/blk-crypto.c b/block/blk-crypto.c index de60f03b4d4b..0fe6ef0eea1d 100644 --- a/block/blk-crypto.c +++ b/block/blk-crypto.c @@ -300,6 +300,7 @@ int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, * @dun_bytes: number of bytes that will be used to specify the DUN when this * key is used * @data_unit_size: the data unit size to use for en/decryption + * @flags: BLK_CRYPTO_CFG_* flags * * Return: 0 on success, -errno on failure. The caller is responsible for * zeroizing both blk_key and key_bytes when done with them. @@ -309,7 +310,7 @@ int blk_crypto_init_key(struct blk_crypto_key *blk_key, enum blk_crypto_key_type key_type, enum blk_crypto_mode_num crypto_mode, unsigned int dun_bytes, - unsigned int data_unit_size) + unsigned int data_unit_size, int flags) { const struct blk_crypto_mode *mode; @@ -318,6 +319,9 @@ int blk_crypto_init_key(struct blk_crypto_key *blk_key, if (crypto_mode >= ARRAY_SIZE(blk_crypto_modes)) return -EINVAL; + if (flags & ~BLK_CRYPTO_CFG_ALLOW_HW) + return -EINVAL; + mode = &blk_crypto_modes[crypto_mode]; switch (key_type) { case BLK_CRYPTO_KEY_TYPE_RAW: @@ -328,6 +332,8 @@ int blk_crypto_init_key(struct blk_crypto_key *blk_key, if (key_size < mode->security_strength || key_size > BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE) return -EINVAL; + if (!(flags & BLK_CRYPTO_CFG_ALLOW_HW)) + return -EINVAL; break; default: return -EINVAL; @@ -343,6 +349,7 @@ int blk_crypto_init_key(struct blk_crypto_key *blk_key, blk_key->crypto_cfg.dun_bytes = dun_bytes; blk_key->crypto_cfg.data_unit_size = data_unit_size; blk_key->crypto_cfg.key_type = key_type; + blk_key->crypto_cfg.flags = flags; blk_key->data_unit_size_bits = ilog2(data_unit_size); blk_key->size = key_size; memcpy(blk_key->bytes, key_bytes, key_size); @@ -368,6 +375,8 @@ bool blk_crypto_config_supported_natively(struct block_device *bdev, if (!profile) return false; + if (!(cfg->flags & BLK_CRYPTO_CFG_ALLOW_HW)) + return false; if (!(profile->modes_supported[cfg->crypto_mode] & cfg->data_unit_size)) return false; if (profile->max_dun_bytes_supported < cfg->dun_bytes) |