xref: /openbmc/linux/certs/Kconfig (revision 74ce1896)
1menu "Certificates for signature checking"
2
3config MODULE_SIG_KEY
4	string "File name or PKCS#11 URI of module signing key"
5	default "certs/signing_key.pem"
6	depends on MODULE_SIG
7	help
8         Provide the file name of a private key/certificate in PEM format,
9         or a PKCS#11 URI according to RFC7512. The file should contain, or
10         the URI should identify, both the certificate and its corresponding
11         private key.
12
13         If this option is unchanged from its default "certs/signing_key.pem",
14         then the kernel will automatically generate the private key and
15         certificate as described in Documentation/module-signing.txt
16
17config SYSTEM_TRUSTED_KEYRING
18	bool "Provide system-wide ring of trusted keys"
19	depends on KEYS
20	depends on ASYMMETRIC_KEY_TYPE
21	help
22	  Provide a system keyring to which trusted keys can be added.  Keys in
23	  the keyring are considered to be trusted.  Keys may be added at will
24	  by the kernel from compiled-in data and from hardware key stores, but
25	  userspace may only add extra keys if those keys can be verified by
26	  keys already in the keyring.
27
28	  Keys in this keyring are used by module signature checking.
29
30config SYSTEM_TRUSTED_KEYS
31	string "Additional X.509 keys for default system keyring"
32	depends on SYSTEM_TRUSTED_KEYRING
33	help
34	  If set, this option should be the filename of a PEM-formatted file
35	  containing trusted X.509 certificates to be included in the default
36	  system keyring. Any certificate used for module signing is implicitly
37	  also trusted.
38
39	  NOTE: If you previously provided keys for the system keyring in the
40	  form of DER-encoded *.x509 files in the top-level build directory,
41	  those are no longer used. You will need to set this option instead.
42
43config SYSTEM_EXTRA_CERTIFICATE
44	bool "Reserve area for inserting a certificate without recompiling"
45	depends on SYSTEM_TRUSTED_KEYRING
46	help
47	  If set, space for an extra certificate will be reserved in the kernel
48	  image. This allows introducing a trusted certificate to the default
49	  system keyring without recompiling the kernel.
50
51config SYSTEM_EXTRA_CERTIFICATE_SIZE
52	int "Number of bytes to reserve for the extra certificate"
53	depends on SYSTEM_EXTRA_CERTIFICATE
54	default 4096
55	help
56	  This is the number of bytes reserved in the kernel image for a
57	  certificate to be inserted.
58
59config SECONDARY_TRUSTED_KEYRING
60	bool "Provide a keyring to which extra trustable keys may be added"
61	depends on SYSTEM_TRUSTED_KEYRING
62	help
63	  If set, provide a keyring to which extra keys may be added, provided
64	  those keys are not blacklisted and are vouched for by a key built
65	  into the kernel or already in the secondary trusted keyring.
66
67config SYSTEM_BLACKLIST_KEYRING
68	bool "Provide system-wide ring of blacklisted keys"
69	depends on KEYS
70	help
71	  Provide a system keyring to which blacklisted keys can be added.
72	  Keys in the keyring are considered entirely untrusted.  Keys in this
73	  keyring are used by the module signature checking to reject loading
74	  of modules signed with a blacklisted key.
75
76config SYSTEM_BLACKLIST_HASH_LIST
77	string "Hashes to be preloaded into the system blacklist keyring"
78	depends on SYSTEM_BLACKLIST_KEYRING
79	help
80	  If set, this option should be the filename of a list of hashes in the
81	  form "<hash>", "<hash>", ... .  This will be included into a C
82	  wrapper to incorporate the list into the kernel.  Each <hash> should
83	  be a string of hex digits.
84
85endmenu
86