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authorEric Biggers <ebiggers@kernel.org>2026-07-15 15:11:41 -0700
committerEric Biggers <ebiggers@kernel.org>2026-07-19 17:34:16 -0700
commitff3ab74623dfe6a76fdcf3d2139c3f699e31984a (patch)
tree5c7b20be7632b84bde79445e6f95dad0b585c5d9
parent1590cf0329716306e948a8fc29f1d3ee87d3989f (diff)
crypto: xts - Split out __xts_verify_key() helper
Make the AES-XTS key verification code callable by the crypto library by splitting out a helper function that doesn't use crypto_skcipher. Reviewed-by: Thomas Huth <thuth@redhat.com> Link: https://patch.msgid.link/20260715221153.246410-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
-rw-r--r--include/crypto/xts.h18
1 files changed, 14 insertions, 4 deletions
diff --git a/include/crypto/xts.h b/include/crypto/xts.h
index 15b16c4853d8..16aef89f021f 100644
--- a/include/crypto/xts.h
+++ b/include/crypto/xts.h
@@ -7,9 +7,9 @@
#include <linux/fips.h>
#define XTS_BLOCK_SIZE 16
+#define XTS_FORBID_WEAK_KEYS (1 << 0)
-static inline int xts_verify_key(struct crypto_skcipher *tfm,
- const u8 *key, unsigned int keylen)
+static inline int __xts_verify_key(const u8 *key, size_t keylen, int flags)
{
/*
* key consists of keys of equal size concatenated, therefore
@@ -29,12 +29,22 @@ static inline int xts_verify_key(struct crypto_skcipher *tfm,
* Ensure that the AES and tweak key are not identical when
* in FIPS mode or the FORBID_WEAK_KEYS flag is set.
*/
- if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
- CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
+ if ((fips_enabled || (flags & XTS_FORBID_WEAK_KEYS)) &&
!crypto_memneq(key, key + (keylen / 2), keylen / 2))
return -EINVAL;
return 0;
}
+static inline int xts_verify_key(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int keylen)
+{
+ int flags = (crypto_skcipher_get_flags(tfm) &
+ CRYPTO_TFM_REQ_FORBID_WEAK_KEYS) ?
+ XTS_FORBID_WEAK_KEYS :
+ 0;
+
+ return __xts_verify_key(key, keylen, flags);
+}
+
#endif /* _CRYPTO_XTS_H */