2 # Key management configuration
6 bool "Enable access key retention support"
7 select ASSOCIATIVE_ARRAY
9 This option provides support for retaining authentication tokens and
10 access keys in the kernel.
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.
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,
21 If you are unsure as to whether this is required, answer N.
25 depends on COMPAT && KEYS
27 config KEYS_REQUEST_CACHE
28 bool "Enable temporary caching of the last request_key() result"
31 This option causes the result of the last successful request_key()
32 call that didn't upcall to the kernel to be cached temporarily in the
33 task_struct. The cache is cleared by exit and just prior to the
34 resumption of userspace.
36 This allows the key used for multiple step processes where each step
37 wants to request a key that is likely the same as the one requested
38 by the last step to save on the searching.
40 An example of such a process is a pathwalk through a network
41 filesystem in which each method needs to request an authentication
42 key. Pathwalk will call multiple methods for each dentry traversed
43 (permission, d_revalidate, lookup, getxattr, getacl, ...).
45 config PERSISTENT_KEYRINGS
46 bool "Enable register of persistent per-UID keyrings"
49 This option provides a register of persistent per-UID keyrings,
50 primarily aimed at Kerberos key storage. The keyrings are persistent
51 in the sense that they stay around after all processes of that UID
52 have exited, not that they survive the machine being rebooted.
54 A particular keyring may be accessed by either the user whose keyring
55 it is or by a process with administrative privileges. The active
56 LSMs gets to rule on which admin-level processes get to access the
59 Keyrings are created and added into the register upon demand and get
60 removed if they expire (a default timeout is set upon creation).
63 bool "Large payload keys"
70 This option provides support for holding large keys within the kernel
71 (for example Kerberos ticket caches). The data may be stored out to
74 If you are unsure as to whether this is required, answer N.
77 tristate "TRUSTED KEYS"
78 depends on KEYS && TCG_TPM
82 select CRYPTO_HASH_INFO
84 This option provides support for creating, sealing, and unsealing
85 keys in the kernel. Trusted keys are random number symmetric keys,
86 generated and RSA-sealed by the TPM. The TPM only unseals the keys,
87 if the boot PCRs and other criteria match. Userspace will only ever
90 If you are unsure as to whether this is required, answer N.
93 tristate "ENCRYPTED KEYS"
102 This option provides support for create/encrypting/decrypting keys
103 in the kernel. Encrypted keys are kernel generated random numbers,
104 which are encrypted/decrypted with a 'master' symmetric key. The
105 'master' key can be either a trusted-key or user-key type.
106 Userspace only ever sees/stores encrypted blobs.
108 If you are unsure as to whether this is required, answer N.
110 config KEY_DH_OPERATIONS
111 bool "Diffie-Hellman operations on retained keys"
117 This option provides support for calculating Diffie-Hellman
118 public keys and shared secrets using values stored as keys
121 If you are unsure as to whether this is required, answer N.