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authorEric Biggers <ebiggers@google.com>2020-07-08 14:55:29 -0700
committerEric Biggers <ebiggers@google.com>2020-07-20 17:26:32 -0700
commite455de313ef8bd1fa05a3eb6ef1bfd96eaf38e2a (patch)
tree00d14f000e9c848a293d8fbe0b8d6494e540c449 /fs/crypto
parent4f74d15fe40833d4fb4f5ead7437aa73840596a5 (diff)
fscrypt: add comments that describe the HKDF info strings
Each HKDF context byte is associated with a specific format of the remaining part of the application-specific info string. Add comments so that it's easier to keep track of what these all are. Link: https://lore.kernel.org/r/20200708215529.146890-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
Diffstat (limited to 'fs/crypto')
-rw-r--r--fs/crypto/fscrypt_private.h14
1 files changed, 7 insertions, 7 deletions
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 5bb40d0109c8..0f154bdbc14b 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -312,13 +312,13 @@ int fscrypt_init_hkdf(struct fscrypt_hkdf *hkdf, const u8 *master_key,
* outputs are unique and cryptographically isolated, i.e. knowledge of one
* output doesn't reveal another.
*/
-#define HKDF_CONTEXT_KEY_IDENTIFIER 1
-#define HKDF_CONTEXT_PER_FILE_ENC_KEY 2
-#define HKDF_CONTEXT_DIRECT_KEY 3
-#define HKDF_CONTEXT_IV_INO_LBLK_64_KEY 4
-#define HKDF_CONTEXT_DIRHASH_KEY 5
-#define HKDF_CONTEXT_IV_INO_LBLK_32_KEY 6
-#define HKDF_CONTEXT_INODE_HASH_KEY 7
+#define HKDF_CONTEXT_KEY_IDENTIFIER 1 /* info=<empty> */
+#define HKDF_CONTEXT_PER_FILE_ENC_KEY 2 /* info=file_nonce */
+#define HKDF_CONTEXT_DIRECT_KEY 3 /* info=mode_num */
+#define HKDF_CONTEXT_IV_INO_LBLK_64_KEY 4 /* info=mode_num||fs_uuid */
+#define HKDF_CONTEXT_DIRHASH_KEY 5 /* info=file_nonce */
+#define HKDF_CONTEXT_IV_INO_LBLK_32_KEY 6 /* info=mode_num||fs_uuid */
+#define HKDF_CONTEXT_INODE_HASH_KEY 7 /* info=<empty> */
int fscrypt_hkdf_expand(const struct fscrypt_hkdf *hkdf, u8 context,
const u8 *info, unsigned int infolen,