fscrypt: rename FS_KEY_DERIVATION_NONCE_SIZE

The name "FS_KEY_DERIVATION_NONCE_SIZE" is a bit outdated since due to
the addition of FSCRYPT_POLICY_FLAG_DIRECT_KEY, the file nonce may now
be used as a tweak instead of for key derivation.  Also, we're now
prefixing the fscrypt constants with "FSCRYPT_" instead of "FS_".

Therefore, rename this constant to FSCRYPT_FILE_NONCE_SIZE.

Link: https://lore.kernel.org/r/20200708215722.147154-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
This commit is contained in:
Eric Biggers 2020-07-08 14:57:22 -07:00
parent e455de313e
commit 1d6217a4f9
6 changed files with 16 additions and 17 deletions

View File

@ -1158,7 +1158,7 @@ setxattr() because of the special semantics of the encryption xattr.
were to be added to or removed from anything other than an empty
directory.) These structs are defined as follows::
#define FS_KEY_DERIVATION_NONCE_SIZE 16
#define FSCRYPT_FILE_NONCE_SIZE 16
#define FSCRYPT_KEY_DESCRIPTOR_SIZE 8
struct fscrypt_context_v1 {
@ -1167,7 +1167,7 @@ directory.) These structs are defined as follows::
u8 filenames_encryption_mode;
u8 flags;
u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
u8 nonce[FSCRYPT_FILE_NONCE_SIZE];
};
#define FSCRYPT_KEY_IDENTIFIER_SIZE 16
@ -1178,7 +1178,7 @@ directory.) These structs are defined as follows::
u8 flags;
u8 __reserved[4];
u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
u8 nonce[FSCRYPT_FILE_NONCE_SIZE];
};
The context structs contain the same information as the corresponding

View File

@ -84,7 +84,7 @@ void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num,
WARN_ON_ONCE(lblk_num > U32_MAX);
lblk_num = (u32)(ci->ci_hashed_ino + lblk_num);
} else if (flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) {
memcpy(iv->nonce, ci->ci_nonce, FS_KEY_DERIVATION_NONCE_SIZE);
memcpy(iv->nonce, ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE);
}
iv->lblk_num = cpu_to_le64(lblk_num);
}

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@ -18,9 +18,9 @@
#define CONST_STRLEN(str) (sizeof(str) - 1)
#define FS_KEY_DERIVATION_NONCE_SIZE 16
#define FSCRYPT_FILE_NONCE_SIZE 16
#define FSCRYPT_MIN_KEY_SIZE 16
#define FSCRYPT_MIN_KEY_SIZE 16
#define FSCRYPT_CONTEXT_V1 1
#define FSCRYPT_CONTEXT_V2 2
@ -31,7 +31,7 @@ struct fscrypt_context_v1 {
u8 filenames_encryption_mode;
u8 flags;
u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
u8 nonce[FSCRYPT_FILE_NONCE_SIZE];
};
struct fscrypt_context_v2 {
@ -41,7 +41,7 @@ struct fscrypt_context_v2 {
u8 flags;
u8 __reserved[4];
u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
u8 nonce[FSCRYPT_FILE_NONCE_SIZE];
};
/*
@ -244,7 +244,7 @@ struct fscrypt_info {
union fscrypt_policy ci_policy;
/* This inode's nonce, copied from the fscrypt_context */
u8 ci_nonce[FS_KEY_DERIVATION_NONCE_SIZE];
u8 ci_nonce[FSCRYPT_FILE_NONCE_SIZE];
/* Hashed inode number. Only set for IV_INO_LBLK_32 */
u32 ci_hashed_ino;
@ -280,7 +280,7 @@ union fscrypt_iv {
__le64 lblk_num;
/* per-file nonce; only set in DIRECT_KEY mode */
u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
u8 nonce[FSCRYPT_FILE_NONCE_SIZE];
};
u8 raw[FSCRYPT_MAX_IV_SIZE];
__le64 dun[FSCRYPT_MAX_IV_SIZE / sizeof(__le64)];

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@ -211,7 +211,7 @@ int fscrypt_derive_dirhash_key(struct fscrypt_info *ci,
int err;
err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf, HKDF_CONTEXT_DIRHASH_KEY,
ci->ci_nonce, FS_KEY_DERIVATION_NONCE_SIZE,
ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE,
(u8 *)&ci->ci_dirhash_key,
sizeof(ci->ci_dirhash_key));
if (err)
@ -292,8 +292,7 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci,
err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf,
HKDF_CONTEXT_PER_FILE_ENC_KEY,
ci->ci_nonce,
FS_KEY_DERIVATION_NONCE_SIZE,
ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE,
derived_key, ci->ci_mode->keysize);
if (err)
return err;
@ -498,7 +497,7 @@ int fscrypt_get_encryption_info(struct inode *inode)
}
memcpy(crypt_info->ci_nonce, fscrypt_context_nonce(&ctx),
FS_KEY_DERIVATION_NONCE_SIZE);
FSCRYPT_FILE_NONCE_SIZE);
if (!fscrypt_supported_policy(&crypt_info->ci_policy, inode)) {
res = -EINVAL;

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@ -45,7 +45,7 @@ static DEFINE_SPINLOCK(fscrypt_direct_keys_lock);
* key is longer, then only the first 'derived_keysize' bytes are used.
*/
static int derive_key_aes(const u8 *master_key,
const u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE],
const u8 nonce[FSCRYPT_FILE_NONCE_SIZE],
u8 *derived_key, unsigned int derived_keysize)
{
int res = 0;
@ -68,7 +68,7 @@ static int derive_key_aes(const u8 *master_key,
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
crypto_req_done, &wait);
res = crypto_skcipher_setkey(tfm, nonce, FS_KEY_DERIVATION_NONCE_SIZE);
res = crypto_skcipher_setkey(tfm, nonce, FSCRYPT_FILE_NONCE_SIZE);
if (res < 0)
goto out;

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@ -529,7 +529,7 @@ int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg)
if (!fscrypt_context_is_valid(&ctx, ret))
return -EINVAL;
if (copy_to_user(arg, fscrypt_context_nonce(&ctx),
FS_KEY_DERIVATION_NONCE_SIZE))
FSCRYPT_FILE_NONCE_SIZE))
return -EFAULT;
return 0;
}