xref: /linux/certs/Kconfig (revision 44f57d78) 
1# SPDX-License-Identifier: GPL-2.0
2menu "Certificates for signature checking"
3
4config MODULE_SIG_KEY
5	string "File name or PKCS#11 URI of module signing key"
6	default "certs/signing_key.pem"
7	depends on MODULE_SIG
8	help
9         Provide the file name of a private key/certificate in PEM format,
10         or a PKCS#11 URI according to RFC7512. The file should contain, or
11         the URI should identify, both the certificate and its corresponding
12         private key.
13
14         If this option is unchanged from its default "certs/signing_key.pem",
15         then the kernel will automatically generate the private key and
16         certificate as described in Documentation/admin-guide/module-signing.rst
17
18config SYSTEM_TRUSTED_KEYRING
19	bool "Provide system-wide ring of trusted keys"
20	depends on KEYS
21	depends on ASYMMETRIC_KEY_TYPE
22	help
23	  Provide a system keyring to which trusted keys can be added.  Keys in
24	  the keyring are considered to be trusted.  Keys may be added at will
25	  by the kernel from compiled-in data and from hardware key stores, but
26	  userspace may only add extra keys if those keys can be verified by
27	  keys already in the keyring.
28
29	  Keys in this keyring are used by module signature checking.
30
31config SYSTEM_TRUSTED_KEYS
32	string "Additional X.509 keys for default system keyring"
33	depends on SYSTEM_TRUSTED_KEYRING
34	help
35	  If set, this option should be the filename of a PEM-formatted file
36	  containing trusted X.509 certificates to be included in the default
37	  system keyring. Any certificate used for module signing is implicitly
38	  also trusted.
39
40	  NOTE: If you previously provided keys for the system keyring in the
41	  form of DER-encoded *.x509 files in the top-level build directory,
42	  those are no longer used. You will need to set this option instead.
43
44config SYSTEM_EXTRA_CERTIFICATE
45	bool "Reserve area for inserting a certificate without recompiling"
46	depends on SYSTEM_TRUSTED_KEYRING
47	help
48	  If set, space for an extra certificate will be reserved in the kernel
49	  image. This allows introducing a trusted certificate to the default
50	  system keyring without recompiling the kernel.
51
52config SYSTEM_EXTRA_CERTIFICATE_SIZE
53	int "Number of bytes to reserve for the extra certificate"
54	depends on SYSTEM_EXTRA_CERTIFICATE
55	default 4096
56	help
57	  This is the number of bytes reserved in the kernel image for a
58	  certificate to be inserted.
59
60config SECONDARY_TRUSTED_KEYRING
61	bool "Provide a keyring to which extra trustable keys may be added"
62	depends on SYSTEM_TRUSTED_KEYRING
63	help
64	  If set, provide a keyring to which extra keys may be added, provided
65	  those keys are not blacklisted and are vouched for by a key built
66	  into the kernel or already in the secondary trusted keyring.
67
68config SYSTEM_BLACKLIST_KEYRING
69	bool "Provide system-wide ring of blacklisted keys"
70	depends on KEYS
71	help
72	  Provide a system keyring to which blacklisted keys can be added.
73	  Keys in the keyring are considered entirely untrusted.  Keys in this
74	  keyring are used by the module signature checking to reject loading
75	  of modules signed with a blacklisted key.
76
77config SYSTEM_BLACKLIST_HASH_LIST
78	string "Hashes to be preloaded into the system blacklist keyring"
79	depends on SYSTEM_BLACKLIST_KEYRING
80	help
81	  If set, this option should be the filename of a list of hashes in the
82	  form "<hash>", "<hash>", ... .  This will be included into a C
83	  wrapper to incorporate the list into the kernel.  Each <hash> should
84	  be a string of hex digits.
85
86endmenu
87