1 # SPDX-License-Identifier: GPL-2.0 1 # SPDX-License-Identifier: GPL-2.0
2 menu "Certificates for signature checking" 2 menu "Certificates for signature checking"
3 3
4 config MODULE_SIG_KEY 4 config MODULE_SIG_KEY
5 string "File name or PKCS#11 URI of mo 5 string "File name or PKCS#11 URI of module signing key"
6 default "certs/signing_key.pem" 6 default "certs/signing_key.pem"
7 depends on MODULE_SIG || (IMA_APPRAISE 7 depends on MODULE_SIG || (IMA_APPRAISE_MODSIG && MODULES)
8 help 8 help
9 Provide the file name of a private ke 9 Provide the file name of a private key/certificate in PEM format,
10 or a PKCS#11 URI according to RFC7512 10 or a PKCS#11 URI according to RFC7512. The file should contain, or
11 the URI should identify, both the cer 11 the URI should identify, both the certificate and its corresponding
12 private key. 12 private key.
13 13
14 If this option is unchanged from its 14 If this option is unchanged from its default "certs/signing_key.pem",
15 then the kernel will automatically ge 15 then the kernel will automatically generate the private key and
16 certificate as described in Documenta 16 certificate as described in Documentation/admin-guide/module-signing.rst
17 17
18 choice 18 choice
19 prompt "Type of module signing key to 19 prompt "Type of module signing key to be generated"
20 depends on MODULE_SIG || (IMA_APPRAISE 20 depends on MODULE_SIG || (IMA_APPRAISE_MODSIG && MODULES)
21 help 21 help
22 The type of module signing key type t 22 The type of module signing key type to generate. This option
23 does not apply if a #PKCS11 URI is us 23 does not apply if a #PKCS11 URI is used.
24 24
25 config MODULE_SIG_KEY_TYPE_RSA 25 config MODULE_SIG_KEY_TYPE_RSA
26 bool "RSA" 26 bool "RSA"
27 help 27 help
28 Use an RSA key for module signing. 28 Use an RSA key for module signing.
29 29
30 config MODULE_SIG_KEY_TYPE_ECDSA 30 config MODULE_SIG_KEY_TYPE_ECDSA
31 bool "ECDSA" 31 bool "ECDSA"
32 select CRYPTO_ECDSA 32 select CRYPTO_ECDSA
33 depends on !(MODULE_SIG_SHA256 || MODU <<
34 help 33 help
35 Use an elliptic curve key (NIST P384) !! 34 Use an elliptic curve key (NIST P384) for module signing. Consider
36 a strong hash of same or higher bit l !! 35 using a strong hash like sha256 or sha384 for hashing modules.
37 sha512 for hashing modules. <<
38 36
39 Note: Remove all ECDSA signing keys, 37 Note: Remove all ECDSA signing keys, e.g. certs/signing_key.pem,
40 when falling back to building Linux 5 38 when falling back to building Linux 5.14 and older kernels.
41 39
42 endchoice 40 endchoice
43 41
44 config SYSTEM_TRUSTED_KEYRING 42 config SYSTEM_TRUSTED_KEYRING
45 bool "Provide system-wide ring of trus 43 bool "Provide system-wide ring of trusted keys"
46 depends on KEYS 44 depends on KEYS
47 depends on ASYMMETRIC_KEY_TYPE 45 depends on ASYMMETRIC_KEY_TYPE
48 depends on X509_CERTIFICATE_PARSER = y 46 depends on X509_CERTIFICATE_PARSER = y
49 help 47 help
50 Provide a system keyring to which tr 48 Provide a system keyring to which trusted keys can be added. Keys in
51 the keyring are considered to be tru 49 the keyring are considered to be trusted. Keys may be added at will
52 by the kernel from compiled-in data 50 by the kernel from compiled-in data and from hardware key stores, but
53 userspace may only add extra keys if 51 userspace may only add extra keys if those keys can be verified by
54 keys already in the keyring. 52 keys already in the keyring.
55 53
56 Keys in this keyring are used by mod 54 Keys in this keyring are used by module signature checking.
57 55
58 config SYSTEM_TRUSTED_KEYS 56 config SYSTEM_TRUSTED_KEYS
59 string "Additional X.509 keys for defa 57 string "Additional X.509 keys for default system keyring"
60 depends on SYSTEM_TRUSTED_KEYRING 58 depends on SYSTEM_TRUSTED_KEYRING
61 help 59 help
62 If set, this option should be the fi 60 If set, this option should be the filename of a PEM-formatted file
63 containing trusted X.509 certificate 61 containing trusted X.509 certificates to be included in the default
64 system keyring. Any certificate used 62 system keyring. Any certificate used for module signing is implicitly
65 also trusted. 63 also trusted.
66 64
67 NOTE: If you previously provided key 65 NOTE: If you previously provided keys for the system keyring in the
68 form of DER-encoded *.x509 files in 66 form of DER-encoded *.x509 files in the top-level build directory,
69 those are no longer used. You will n 67 those are no longer used. You will need to set this option instead.
70 68
71 config SYSTEM_EXTRA_CERTIFICATE 69 config SYSTEM_EXTRA_CERTIFICATE
72 bool "Reserve area for inserting a cer 70 bool "Reserve area for inserting a certificate without recompiling"
73 depends on SYSTEM_TRUSTED_KEYRING 71 depends on SYSTEM_TRUSTED_KEYRING
74 help 72 help
75 If set, space for an extra certifica 73 If set, space for an extra certificate will be reserved in the kernel
76 image. This allows introducing a tru 74 image. This allows introducing a trusted certificate to the default
77 system keyring without recompiling t 75 system keyring without recompiling the kernel.
78 76
79 config SYSTEM_EXTRA_CERTIFICATE_SIZE 77 config SYSTEM_EXTRA_CERTIFICATE_SIZE
80 int "Number of bytes to reserve for th 78 int "Number of bytes to reserve for the extra certificate"
81 depends on SYSTEM_EXTRA_CERTIFICATE 79 depends on SYSTEM_EXTRA_CERTIFICATE
82 default 4096 80 default 4096
83 help 81 help
84 This is the number of bytes reserved 82 This is the number of bytes reserved in the kernel image for a
85 certificate to be inserted. 83 certificate to be inserted.
86 84
87 config SECONDARY_TRUSTED_KEYRING 85 config SECONDARY_TRUSTED_KEYRING
88 bool "Provide a keyring to which extra 86 bool "Provide a keyring to which extra trustable keys may be added"
89 depends on SYSTEM_TRUSTED_KEYRING 87 depends on SYSTEM_TRUSTED_KEYRING
90 help 88 help
91 If set, provide a keyring to which e 89 If set, provide a keyring to which extra keys may be added, provided
92 those keys are not blacklisted and a 90 those keys are not blacklisted and are vouched for by a key built
93 into the kernel, machine keyring (if !! 91 into the kernel or already in the secondary trusted keyring.
94 secondary trusted keyring. <<
95 <<
96 config SECONDARY_TRUSTED_KEYRING_SIGNED_BY_BUI <<
97 bool "Only allow additional certs sign <<
98 depends on SECONDARY_TRUSTED_KEYRING <<
99 help <<
100 If set, only certificates signed by <<
101 keyring may be loaded onto the secon <<
102 <<
103 Note: The machine keyring, if config <<
104 secondary keyring. When enabling th <<
105 to also configure INTEGRITY_CA_MACHI <<
106 linking code signing keys with imput <<
107 trusted keyring. <<
108 92
109 config SYSTEM_BLACKLIST_KEYRING 93 config SYSTEM_BLACKLIST_KEYRING
110 bool "Provide system-wide ring of blac 94 bool "Provide system-wide ring of blacklisted keys"
111 depends on KEYS 95 depends on KEYS
112 help 96 help
113 Provide a system keyring to which bl 97 Provide a system keyring to which blacklisted keys can be added.
114 Keys in the keyring are considered e 98 Keys in the keyring are considered entirely untrusted. Keys in this
115 keyring are used by the module signa 99 keyring are used by the module signature checking to reject loading
116 of modules signed with a blacklisted 100 of modules signed with a blacklisted key.
117 101
118 config SYSTEM_BLACKLIST_HASH_LIST 102 config SYSTEM_BLACKLIST_HASH_LIST
119 string "Hashes to be preloaded into th 103 string "Hashes to be preloaded into the system blacklist keyring"
120 depends on SYSTEM_BLACKLIST_KEYRING 104 depends on SYSTEM_BLACKLIST_KEYRING
121 help 105 help
122 If set, this option should be the fi 106 If set, this option should be the filename of a list of hashes in the
123 form "<hash>", "<hash>", ... . This 107 form "<hash>", "<hash>", ... . This will be included into a C
124 wrapper to incorporate the list into 108 wrapper to incorporate the list into the kernel. Each <hash> must be a
125 string starting with a prefix ("tbs" 109 string starting with a prefix ("tbs" or "bin"), then a colon (":"), and
126 finally an even number of hexadecima 110 finally an even number of hexadecimal lowercase characters (up to 128).
127 Certificate hashes can be generated 111 Certificate hashes can be generated with
128 tools/certs/print-cert-tbs-hash.sh . 112 tools/certs/print-cert-tbs-hash.sh .
129 113
130 config SYSTEM_REVOCATION_LIST 114 config SYSTEM_REVOCATION_LIST
131 bool "Provide system-wide ring of revo 115 bool "Provide system-wide ring of revocation certificates"
132 depends on SYSTEM_BLACKLIST_KEYRING 116 depends on SYSTEM_BLACKLIST_KEYRING
133 depends on PKCS7_MESSAGE_PARSER=y 117 depends on PKCS7_MESSAGE_PARSER=y
134 help 118 help
135 If set, this allows revocation certi 119 If set, this allows revocation certificates to be stored in the
136 blacklist keyring and implements a h 120 blacklist keyring and implements a hook whereby a PKCS#7 message can
137 be checked to see if it matches such 121 be checked to see if it matches such a certificate.
138 122
139 config SYSTEM_REVOCATION_KEYS 123 config SYSTEM_REVOCATION_KEYS
140 string "X.509 certificates to be prelo 124 string "X.509 certificates to be preloaded into the system blacklist keyring"
141 depends on SYSTEM_REVOCATION_LIST 125 depends on SYSTEM_REVOCATION_LIST
142 help 126 help
143 If set, this option should be the fi 127 If set, this option should be the filename of a PEM-formatted file
144 containing X.509 certificates to be 128 containing X.509 certificates to be included in the default blacklist
145 keyring. 129 keyring.
146 130
147 config SYSTEM_BLACKLIST_AUTH_UPDATE 131 config SYSTEM_BLACKLIST_AUTH_UPDATE
148 bool "Allow root to add signed blackli 132 bool "Allow root to add signed blacklist keys"
149 depends on SYSTEM_BLACKLIST_KEYRING 133 depends on SYSTEM_BLACKLIST_KEYRING
150 depends on SYSTEM_DATA_VERIFICATION 134 depends on SYSTEM_DATA_VERIFICATION
151 help 135 help
152 If set, provide the ability to load 136 If set, provide the ability to load new blacklist keys at run time if
153 they are signed and vouched by a cer 137 they are signed and vouched by a certificate from the builtin trusted
154 keyring. The PKCS#7 signature of th 138 keyring. The PKCS#7 signature of the description is set in the key
155 payload. Blacklist keys cannot be r 139 payload. Blacklist keys cannot be removed.
156 140
157 endmenu 141 endmenu
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