xref: /openbmc/linux/security/keys/Kconfig (revision 6f52b16c) 
1#
2# Key management configuration
3#
4
5config KEYS
6	bool "Enable access key retention support"
7	select ASSOCIATIVE_ARRAY
8	help
9	  This option provides support for retaining authentication tokens and
10	  access keys in the kernel.
11
12	  It also includes provision of methods by which such keys might be
13	  associated with a process so that network filesystems, encryption
14	  support and the like can find them.
15
16	  Furthermore, a special type of key is available that acts as keyring:
17	  a searchable sequence of keys. Each process is equipped with access
18	  to five standard keyrings: UID-specific, GID-specific, session,
19	  process and thread.
20
21	  If you are unsure as to whether this is required, answer N.
22
23config KEYS_COMPAT
24	def_bool y
25	depends on COMPAT && KEYS
26
27config PERSISTENT_KEYRINGS
28	bool "Enable register of persistent per-UID keyrings"
29	depends on KEYS
30	help
31	  This option provides a register of persistent per-UID keyrings,
32	  primarily aimed at Kerberos key storage.  The keyrings are persistent
33	  in the sense that they stay around after all processes of that UID
34	  have exited, not that they survive the machine being rebooted.
35
36	  A particular keyring may be accessed by either the user whose keyring
37	  it is or by a process with administrative privileges.  The active
38	  LSMs gets to rule on which admin-level processes get to access the
39	  cache.
40
41	  Keyrings are created and added into the register upon demand and get
42	  removed if they expire (a default timeout is set upon creation).
43
44config BIG_KEYS
45	bool "Large payload keys"
46	depends on KEYS
47	depends on TMPFS
48	select CRYPTO
49	select CRYPTO_AES
50	select CRYPTO_GCM
51	help
52	  This option provides support for holding large keys within the kernel
53	  (for example Kerberos ticket caches).  The data may be stored out to
54	  swapspace by tmpfs.
55
56	  If you are unsure as to whether this is required, answer N.
57
58config TRUSTED_KEYS
59	tristate "TRUSTED KEYS"
60	depends on KEYS && TCG_TPM
61	select CRYPTO
62	select CRYPTO_HMAC
63	select CRYPTO_SHA1
64	select CRYPTO_HASH_INFO
65	help
66	  This option provides support for creating, sealing, and unsealing
67	  keys in the kernel. Trusted keys are random number symmetric keys,
68	  generated and RSA-sealed by the TPM. The TPM only unseals the keys,
69	  if the boot PCRs and other criteria match.  Userspace will only ever
70	  see encrypted blobs.
71
72	  If you are unsure as to whether this is required, answer N.
73
74config ENCRYPTED_KEYS
75	tristate "ENCRYPTED KEYS"
76	depends on KEYS
77	select CRYPTO
78	select CRYPTO_HMAC
79	select CRYPTO_AES
80	select CRYPTO_CBC
81	select CRYPTO_SHA256
82	select CRYPTO_RNG
83	help
84	  This option provides support for create/encrypting/decrypting keys
85	  in the kernel.  Encrypted keys are kernel generated random numbers,
86	  which are encrypted/decrypted with a 'master' symmetric key. The
87	  'master' key can be either a trusted-key or user-key type.
88	  Userspace only ever sees/stores encrypted blobs.
89
90	  If you are unsure as to whether this is required, answer N.
91
92config KEY_DH_OPERATIONS
93       bool "Diffie-Hellman operations on retained keys"
94       depends on KEYS
95       select CRYPTO
96       select CRYPTO_HASH
97       select CRYPTO_DH
98       help
99	 This option provides support for calculating Diffie-Hellman
100	 public keys and shared secrets using values stored as keys
101	 in the kernel.
102
103	 If you are unsure as to whether this is required, answer N.
104