xref: /openbmc/linux/security/keys/Kconfig (revision 23c2b932)
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 PERSISTENT_KEYRINGS
24	bool "Enable register of persistent per-UID keyrings"
25	depends on KEYS
26	help
27	  This option provides a register of persistent per-UID keyrings,
28	  primarily aimed at Kerberos key storage.  The keyrings are persistent
29	  in the sense that they stay around after all processes of that UID
30	  have exited, not that they survive the machine being rebooted.
31
32	  A particular keyring may be accessed by either the user whose keyring
33	  it is or by a process with administrative privileges.  The active
34	  LSMs gets to rule on which admin-level processes get to access the
35	  cache.
36
37	  Keyrings are created and added into the register upon demand and get
38	  removed if they expire (a default timeout is set upon creation).
39
40config BIG_KEYS
41	bool "Large payload keys"
42	depends on KEYS
43	depends on TMPFS
44	select CRYPTO
45	select CRYPTO_AES
46	select CRYPTO_ECB
47	select CRYPTO_RNG
48	help
49	  This option provides support for holding large keys within the kernel
50	  (for example Kerberos ticket caches).  The data may be stored out to
51	  swapspace by tmpfs.
52
53	  If you are unsure as to whether this is required, answer N.
54
55config TRUSTED_KEYS
56	tristate "TRUSTED KEYS"
57	depends on KEYS && TCG_TPM
58	select CRYPTO
59	select CRYPTO_HMAC
60	select CRYPTO_SHA1
61	select CRYPTO_HASH_INFO
62	help
63	  This option provides support for creating, sealing, and unsealing
64	  keys in the kernel. Trusted keys are random number symmetric keys,
65	  generated and RSA-sealed by the TPM. The TPM only unseals the keys,
66	  if the boot PCRs and other criteria match.  Userspace will only ever
67	  see encrypted blobs.
68
69	  If you are unsure as to whether this is required, answer N.
70
71config ENCRYPTED_KEYS
72	tristate "ENCRYPTED KEYS"
73	depends on KEYS
74	select CRYPTO
75	select CRYPTO_HMAC
76	select CRYPTO_AES
77	select CRYPTO_CBC
78	select CRYPTO_SHA256
79	select CRYPTO_RNG
80	help
81	  This option provides support for create/encrypting/decrypting keys
82	  in the kernel.  Encrypted keys are kernel generated random numbers,
83	  which are encrypted/decrypted with a 'master' symmetric key. The
84	  'master' key can be either a trusted-key or user-key type.
85	  Userspace only ever sees/stores encrypted blobs.
86
87	  If you are unsure as to whether this is required, answer N.
88
89config KEY_DH_OPERATIONS
90       bool "Diffie-Hellman operations on retained keys"
91       depends on KEYS
92       select MPILIB
93       help
94	 This option provides support for calculating Diffie-Hellman
95	 public keys and shared secrets using values stored as keys
96	 in the kernel.
97
98	 If you are unsure as to whether this is required, answer N.
99