1# SPDX-License-Identifier: GPL-2.0-only
  2#
  3# Key management configuration
  4#
  5
  6config KEYS
  7	bool "Enable access key retention support"
  8	select ASSOCIATIVE_ARRAY
  9	help
 10	  This option provides support for retaining authentication tokens and
 11	  access keys in the kernel.
 12
 13	  It also includes provision of methods by which such keys might be
 14	  associated with a process so that network filesystems, encryption
 15	  support and the like can find them.
 16
 17	  Furthermore, a special type of key is available that acts as keyring:
 18	  a searchable sequence of keys. Each process is equipped with access
 19	  to five standard keyrings: UID-specific, GID-specific, session,
 20	  process and thread.
 21
 22	  If you are unsure as to whether this is required, answer N.
 23
 24config KEYS_REQUEST_CACHE
 25	bool "Enable temporary caching of the last request_key() result"
 26	depends on KEYS
 27	help
 28	  This option causes the result of the last successful request_key()
 29	  call that didn't upcall to the kernel to be cached temporarily in the
 30	  task_struct.  The cache is cleared by exit and just prior to the
 31	  resumption of userspace.
 32
 33	  This allows the key used for multiple step processes where each step
 34	  wants to request a key that is likely the same as the one requested
 35	  by the last step to save on the searching.
 36
 37	  An example of such a process is a pathwalk through a network
 38	  filesystem in which each method needs to request an authentication
 39	  key.  Pathwalk will call multiple methods for each dentry traversed
 40	  (permission, d_revalidate, lookup, getxattr, getacl, ...).
 41
 42config PERSISTENT_KEYRINGS
 43	bool "Enable register of persistent per-UID keyrings"
 44	depends on KEYS
 45	help
 46	  This option provides a register of persistent per-UID keyrings,
 47	  primarily aimed at Kerberos key storage.  The keyrings are persistent
 48	  in the sense that they stay around after all processes of that UID
 49	  have exited, not that they survive the machine being rebooted.
 50
 51	  A particular keyring may be accessed by either the user whose keyring
 52	  it is or by a process with administrative privileges.  The active
 53	  LSMs gets to rule on which admin-level processes get to access the
 54	  cache.
 55
 56	  Keyrings are created and added into the register upon demand and get
 57	  removed if they expire (a default timeout is set upon creation).
 58
 59config BIG_KEYS
 60	bool "Large payload keys"
 61	depends on KEYS
 62	depends on TMPFS
 63	depends on CRYPTO_LIB_CHACHA20POLY1305 = y
 64	help
 65	  This option provides support for holding large keys within the kernel
 66	  (for example Kerberos ticket caches).  The data may be stored out to
 67	  swapspace by tmpfs.
 68
 69	  If you are unsure as to whether this is required, answer N.
 70
 71config TRUSTED_KEYS
 72	tristate "TRUSTED KEYS"
 73	depends on KEYS && TCG_TPM
 74	select CRYPTO
 75	select CRYPTO_HMAC
 76	select CRYPTO_SHA1
 77	select CRYPTO_HASH_INFO
 78	help
 79	  This option provides support for creating, sealing, and unsealing
 80	  keys in the kernel. Trusted keys are random number symmetric keys,
 81	  generated and RSA-sealed by the TPM. The TPM only unseals the keys,
 82	  if the boot PCRs and other criteria match.  Userspace will only ever
 83	  see encrypted blobs.
 84
 85	  If you are unsure as to whether this is required, answer N.
 86
 87config ENCRYPTED_KEYS
 88	tristate "ENCRYPTED KEYS"
 89	depends on KEYS
 90	select CRYPTO
 91	select CRYPTO_HMAC
 92	select CRYPTO_AES
 93	select CRYPTO_CBC
 94	select CRYPTO_SHA256
 95	select CRYPTO_RNG
 96	help
 97	  This option provides support for create/encrypting/decrypting keys
 98	  in the kernel.  Encrypted keys are kernel generated random numbers,
 99	  which are encrypted/decrypted with a 'master' symmetric key. The
100	  'master' key can be either a trusted-key or user-key type.
101	  Userspace only ever sees/stores encrypted blobs.
102
103	  If you are unsure as to whether this is required, answer N.
104
105config KEY_DH_OPERATIONS
106       bool "Diffie-Hellman operations on retained keys"
107       depends on KEYS
108       select CRYPTO
109       select CRYPTO_HASH
110       select CRYPTO_DH
111       help
112	 This option provides support for calculating Diffie-Hellman
113	 public keys and shared secrets using values stored as keys
114	 in the kernel.
115
116	 If you are unsure as to whether this is required, answer N.
117
118config KEY_NOTIFICATIONS
119	bool "Provide key/keyring change notifications"
120	depends on KEYS && WATCH_QUEUE
121	help
122	  This option provides support for getting change notifications on keys
123	  and keyrings on which the caller has View permission.  This makes use
124	  of the /dev/watch_queue misc device to handle the notification
125	  buffer and provides KEYCTL_WATCH_KEY to enable/disable watches.
 
 
 
 
 
 
 
 
 

 
 1#
 2# Key management configuration
 3#
 4
 5config KEYS
 6	bool "Enable access key retention support"
 
 7	help
 8	  This option provides support for retaining authentication tokens and
 9	  access keys in the kernel.
10
11	  It also includes provision of methods by which such keys might be
12	  associated with a process so that network filesystems, encryption
13	  support and the like can find them.
14
15	  Furthermore, a special type of key is available that acts as keyring:
16	  a searchable sequence of keys. Each process is equipped with access
17	  to five standard keyrings: UID-specific, GID-specific, session,
18	  process and thread.
19
20	  If you are unsure as to whether this is required, answer N.
21
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
22config TRUSTED_KEYS
23	tristate "TRUSTED KEYS"
24	depends on KEYS && TCG_TPM
25	select CRYPTO
26	select CRYPTO_HMAC
27	select CRYPTO_SHA1
 
28	help
29	  This option provides support for creating, sealing, and unsealing
30	  keys in the kernel. Trusted keys are random number symmetric keys,
31	  generated and RSA-sealed by the TPM. The TPM only unseals the keys,
32	  if the boot PCRs and other criteria match.  Userspace will only ever
33	  see encrypted blobs.
34
35	  If you are unsure as to whether this is required, answer N.
36
37config ENCRYPTED_KEYS
38	tristate "ENCRYPTED KEYS"
39	depends on KEYS
40	select CRYPTO
41	select CRYPTO_HMAC
42	select CRYPTO_AES
43	select CRYPTO_CBC
44	select CRYPTO_SHA256
45	select CRYPTO_RNG
46	help
47	  This option provides support for create/encrypting/decrypting keys
48	  in the kernel.  Encrypted keys are kernel generated random numbers,
49	  which are encrypted/decrypted with a 'master' symmetric key. The
50	  'master' key can be either a trusted-key or user-key type.
51	  Userspace only ever sees/stores encrypted blobs.
52
53	  If you are unsure as to whether this is required, answer N.
54
55config KEYS_DEBUG_PROC_KEYS
56	bool "Enable the /proc/keys file by which keys may be viewed"
57	depends on KEYS
 
 
 
 
 
 
 
 
 
 
 
 
 
58	help
59	  This option turns on support for the /proc/keys file - through which
60	  can be listed all the keys on the system that are viewable by the
61	  reading process.
62
63	  The only keys included in the list are those that grant View
64	  permission to the reading process whether or not it possesses them.
65	  Note that LSM security checks are still performed, and may further
66	  filter out keys that the current process is not authorised to view.
67
68	  Only key attributes are listed here; key payloads are not included in
69	  the resulting table.
70
71	  If you are unsure as to whether this is required, answer N.