Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:fs\crypto\keysetup.c Create Date:2022-07-28 20:24:00
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Name:Find the master key, then set up the inode's actual encryption key.* If the master key is found in the filesystem-level keyring, then the* corresponding 'struct key' is returned in *master_key_ret with* ->mk_secret_sem read-locked

Proto:static int setup_file_encryption_key(struct fscrypt_info *ci, struct key **master_key_ret)

Type:int

Parameter:

TypeParameterName
struct fscrypt_info *ci
struct key **master_key_ret
236  struct fscrypt_master_key * mk = NULL
241  Case version == Legacy policy version; ad-hoc KDF and no key verification.* For new encrypted directories, use fscrypt_policy_v2 instead.* Careful: the .version field for this is actually 0, not 1.
242  of FSCRYPT_KEY_SPEC_TYPE_* = v1 policy keys are specified by an arbitrary 8-byte key "descriptor",* matching fscrypt_policy_v1::master_key_descriptor.
243  memcpy(descriptor, master_key_descriptor, FSCRYPT_KEY_DESCRIPTOR_SIZE)
246  Break
247  Case version == New policy version with HKDF and key verification (recommended).
248  of FSCRYPT_KEY_SPEC_TYPE_* = v2 policy keys are specified by a 16-byte key "identifier" which the kernel* calculates as a cryptographic hash of the key itself,* matching fscrypt_policy_v2::master_key_identifier.
249  memcpy(identifier, master_key_identifier, FSCRYPT_KEY_IDENTIFIER_SIZE)
252  Break
253  Default
254  WARN_ON(1)
255  Return -EINVAL
258  key = Find the specified master key in ->s_master_keys.* Returns ERR_PTR(-ENOKEY) if not found.
259  If IS_ERR(key) Then
260  If key != ERR_PTR( - ENOKEY) || version != Legacy policy version; ad-hoc KDF and no key verification.* For new encrypted directories, use fscrypt_policy_v2 instead.* Careful: the .version field for this is actually 0, not 1. Then Return PTR_ERR(key)
270  Return fscrypt_setup_v1_file_key_via_subscribed_keyrings(ci)
273  mk = data[0]
274  lock for reading
277  If Not is_master_key_secret_present( & The secret key material. After FS_IOC_REMOVE_ENCRYPTION_KEY is* executed, this is wiped and no new inodes can be unlocked with this* key; however, there may still be inodes in ->mk_decrypted_inodes* which could not be evicted) Then
278  err = -ENOKEY
279  Go to out_release_key
288  If Size of the raw key in bytes. Set even if ->raw isn't set. < keysize Then
289  fscrypt_warn(NULL, "key with %s %*phN is too short (got %u bytes, need %u+ bytes)", master_key_spec_type( & mk_spec), master_key_spec_len( & mk_spec), (u8 * ) & u, Size of the raw key in bytes. Set even if ->raw isn't set. , keysize)
294  err = -ENOKEY
295  Go to out_release_key
299  Case version == Legacy policy version; ad-hoc KDF and no key verification.* For new encrypted directories, use fscrypt_policy_v2 instead.* Careful: the .version field for this is actually 0, not 1.
300  err = fscrypt_setup_v1_file_key(ci, For v1 policy keys: the raw key. Wiped for v2 policy keys. )
301  Break
302  Case version == New policy version with HKDF and key verification (recommended).
303  err = fscrypt_setup_v2_file_key(ci, mk)
304  Break
305  Default
306  WARN_ON(1)
307  err = -EINVAL
308  Break
310  If err Then Go to out_release_key
313  master_key_ret = key
314  Return 0
316  out_release_key :
317  lease a read lock
318  key_put(key)
319  Return err
Caller
NameDescribe
fscrypt_get_encryption_info