1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 # 2 #
3 # Key management configuration 3 # Key management configuration
4 # 4 #
5 5
6 config KEYS 6 config KEYS
7 bool "Enable access key retention supp 7 bool "Enable access key retention support"
8 select ASSOCIATIVE_ARRAY 8 select ASSOCIATIVE_ARRAY
9 help 9 help
10 This option provides support for ret 10 This option provides support for retaining authentication tokens and
11 access keys in the kernel. 11 access keys in the kernel.
12 12
13 It also includes provision of method 13 It also includes provision of methods by which such keys might be
14 associated with a process so that ne 14 associated with a process so that network filesystems, encryption
15 support and the like can find them. 15 support and the like can find them.
16 16
17 Furthermore, a special type of key i 17 Furthermore, a special type of key is available that acts as keyring:
18 a searchable sequence of keys. Each 18 a searchable sequence of keys. Each process is equipped with access
19 to five standard keyrings: UID-speci 19 to five standard keyrings: UID-specific, GID-specific, session,
20 process and thread. 20 process and thread.
21 21
22 If you are unsure as to whether this 22 If you are unsure as to whether this is required, answer N.
23 23
24 config KEYS_REQUEST_CACHE 24 config KEYS_REQUEST_CACHE
25 bool "Enable temporary caching of the 25 bool "Enable temporary caching of the last request_key() result"
26 depends on KEYS 26 depends on KEYS
27 help 27 help
28 This option causes the result of the 28 This option causes the result of the last successful request_key()
29 call that didn't upcall to the kerne 29 call that didn't upcall to the kernel to be cached temporarily in the
30 task_struct. The cache is cleared b 30 task_struct. The cache is cleared by exit and just prior to the
31 resumption of userspace. 31 resumption of userspace.
32 32
33 This allows the key used for multipl 33 This allows the key used for multiple step processes where each step
34 wants to request a key that is likel 34 wants to request a key that is likely the same as the one requested
35 by the last step to save on the sear 35 by the last step to save on the searching.
36 36
37 An example of such a process is a pa 37 An example of such a process is a pathwalk through a network
38 filesystem in which each method need 38 filesystem in which each method needs to request an authentication
39 key. Pathwalk will call multiple me 39 key. Pathwalk will call multiple methods for each dentry traversed
40 (permission, d_revalidate, lookup, g 40 (permission, d_revalidate, lookup, getxattr, getacl, ...).
41 41
42 config PERSISTENT_KEYRINGS 42 config PERSISTENT_KEYRINGS
43 bool "Enable register of persistent pe 43 bool "Enable register of persistent per-UID keyrings"
44 depends on KEYS 44 depends on KEYS
45 help 45 help
46 This option provides a register of p 46 This option provides a register of persistent per-UID keyrings,
47 primarily aimed at Kerberos key stor 47 primarily aimed at Kerberos key storage. The keyrings are persistent
48 in the sense that they stay around a 48 in the sense that they stay around after all processes of that UID
49 have exited, not that they survive t 49 have exited, not that they survive the machine being rebooted.
50 50
51 A particular keyring may be accessed 51 A particular keyring may be accessed by either the user whose keyring
52 it is or by a process with administr 52 it is or by a process with administrative privileges. The active
53 LSMs gets to rule on which admin-lev 53 LSMs gets to rule on which admin-level processes get to access the
54 cache. 54 cache.
55 55
56 Keyrings are created and added into 56 Keyrings are created and added into the register upon demand and get
57 removed if they expire (a default ti 57 removed if they expire (a default timeout is set upon creation).
58 58
59 config BIG_KEYS 59 config BIG_KEYS
60 bool "Large payload keys" 60 bool "Large payload keys"
61 depends on KEYS 61 depends on KEYS
62 depends on TMPFS 62 depends on TMPFS
63 depends on CRYPTO_LIB_CHACHA20POLY1305 63 depends on CRYPTO_LIB_CHACHA20POLY1305 = y
64 help 64 help
65 This option provides support for hol 65 This option provides support for holding large keys within the kernel
66 (for example Kerberos ticket caches) 66 (for example Kerberos ticket caches). The data may be stored out to
67 swapspace by tmpfs. 67 swapspace by tmpfs.
68 68
69 If you are unsure as to whether this 69 If you are unsure as to whether this is required, answer N.
70 70
71 config TRUSTED_KEYS 71 config TRUSTED_KEYS
72 tristate "TRUSTED KEYS" 72 tristate "TRUSTED KEYS"
73 depends on KEYS 73 depends on KEYS
74 help 74 help
75 This option provides support for cre 75 This option provides support for creating, sealing, and unsealing
76 keys in the kernel. Trusted keys are 76 keys in the kernel. Trusted keys are random number symmetric keys,
77 generated and sealed by a trust sour 77 generated and sealed by a trust source selected at kernel boot-time.
78 Userspace will only ever see encrypt 78 Userspace will only ever see encrypted blobs.
79 79
80 If you are unsure as to whether this 80 If you are unsure as to whether this is required, answer N.
81 81
82 if TRUSTED_KEYS 82 if TRUSTED_KEYS
83 source "security/keys/trusted-keys/Kconfig" 83 source "security/keys/trusted-keys/Kconfig"
84 endif 84 endif
85 85
86 config ENCRYPTED_KEYS 86 config ENCRYPTED_KEYS
87 tristate "ENCRYPTED KEYS" 87 tristate "ENCRYPTED KEYS"
88 depends on KEYS 88 depends on KEYS
89 select CRYPTO 89 select CRYPTO
90 select CRYPTO_HMAC 90 select CRYPTO_HMAC
91 select CRYPTO_AES 91 select CRYPTO_AES
92 select CRYPTO_CBC 92 select CRYPTO_CBC
93 select CRYPTO_SHA256 93 select CRYPTO_SHA256
94 select CRYPTO_RNG 94 select CRYPTO_RNG
95 help 95 help
96 This option provides support for cre 96 This option provides support for create/encrypting/decrypting keys
97 in the kernel. Encrypted keys are i 97 in the kernel. Encrypted keys are instantiated using kernel
98 generated random numbers or provided 98 generated random numbers or provided decrypted data, and are
99 encrypted/decrypted with a 'master' 99 encrypted/decrypted with a 'master' symmetric key. The 'master'
100 key can be either a trusted-key or u 100 key can be either a trusted-key or user-key type. Only encrypted
101 blobs are ever output to Userspace. 101 blobs are ever output to Userspace.
102 102
103 If you are unsure as to whether this 103 If you are unsure as to whether this is required, answer N.
104 104
105 config USER_DECRYPTED_DATA 105 config USER_DECRYPTED_DATA
106 bool "Allow encrypted keys with user d 106 bool "Allow encrypted keys with user decrypted data"
107 depends on ENCRYPTED_KEYS 107 depends on ENCRYPTED_KEYS
108 help 108 help
109 This option provides support for ins 109 This option provides support for instantiating encrypted keys using
110 user-provided decrypted data. The d 110 user-provided decrypted data. The decrypted data must be hex-ascii
111 encoded. 111 encoded.
112 112
113 If you are unsure as to whether this 113 If you are unsure as to whether this is required, answer N.
114 114
115 config KEY_DH_OPERATIONS 115 config KEY_DH_OPERATIONS
116 bool "Diffie-Hellman operations on reta 116 bool "Diffie-Hellman operations on retained keys"
117 depends on KEYS 117 depends on KEYS
118 select CRYPTO 118 select CRYPTO
119 select CRYPTO_KDF800108_CTR 119 select CRYPTO_KDF800108_CTR
120 select CRYPTO_DH 120 select CRYPTO_DH
121 help 121 help
122 This option provides support for calc 122 This option provides support for calculating Diffie-Hellman
123 public keys and shared secrets using 123 public keys and shared secrets using values stored as keys
124 in the kernel. 124 in the kernel.
125 125
126 If you are unsure as to whether this 126 If you are unsure as to whether this is required, answer N.
127 127
128 config KEY_NOTIFICATIONS 128 config KEY_NOTIFICATIONS
129 bool "Provide key/keyring change notif 129 bool "Provide key/keyring change notifications"
130 depends on KEYS && WATCH_QUEUE 130 depends on KEYS && WATCH_QUEUE
131 help 131 help
132 This option provides support for get 132 This option provides support for getting change notifications
133 on keys and keyrings on which the ca 133 on keys and keyrings on which the caller has View permission.
134 This makes use of pipes to handle th 134 This makes use of pipes to handle the notification buffer and
135 provides KEYCTL_WATCH_KEY to enable/ 135 provides KEYCTL_WATCH_KEY to enable/disable watches.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.