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 || (IMA_APPRAISE_MODSIG && MODULES) 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 18choice 19 prompt "Type of module signing key to be generated" 20 default MODULE_SIG_KEY_TYPE_RSA 21 help 22 The type of module signing key type to generate. This option 23 does not apply if a #PKCS11 URI is used. 24 25config MODULE_SIG_KEY_TYPE_RSA 26 bool "RSA" 27 depends on MODULE_SIG || (IMA_APPRAISE_MODSIG && MODULES) 28 help 29 Use an RSA key for module signing. 30 31config MODULE_SIG_KEY_TYPE_ECDSA 32 bool "ECDSA" 33 select CRYPTO_ECDSA 34 depends on MODULE_SIG || (IMA_APPRAISE_MODSIG && MODULES) 35 help 36 Use an elliptic curve key (NIST P384) for module signing. Consider 37 using a strong hash like sha256 or sha384 for hashing modules. 38 39 Note: Remove all ECDSA signing keys, e.g. certs/signing_key.pem, 40 when falling back to building Linux 5.14 and older kernels. 41 42endchoice 43 44config SYSTEM_TRUSTED_KEYRING 45 bool "Provide system-wide ring of trusted keys" 46 depends on KEYS 47 depends on ASYMMETRIC_KEY_TYPE 48 help 49 Provide a system keyring to which trusted keys can be added. Keys in 50 the keyring are considered to be trusted. Keys may be added at will 51 by the kernel from compiled-in data and from hardware key stores, but 52 userspace may only add extra keys if those keys can be verified by 53 keys already in the keyring. 54 55 Keys in this keyring are used by module signature checking. 56 57config SYSTEM_TRUSTED_KEYS 58 string "Additional X.509 keys for default system keyring" 59 depends on SYSTEM_TRUSTED_KEYRING 60 help 61 If set, this option should be the filename of a PEM-formatted file 62 containing trusted X.509 certificates to be included in the default 63 system keyring. Any certificate used for module signing is implicitly 64 also trusted. 65 66 NOTE: If you previously provided keys for the system keyring in the 67 form of DER-encoded *.x509 files in the top-level build directory, 68 those are no longer used. You will need to set this option instead. 69 70config SYSTEM_EXTRA_CERTIFICATE 71 bool "Reserve area for inserting a certificate without recompiling" 72 depends on SYSTEM_TRUSTED_KEYRING 73 help 74 If set, space for an extra certificate will be reserved in the kernel 75 image. This allows introducing a trusted certificate to the default 76 system keyring without recompiling the kernel. 77 78config SYSTEM_EXTRA_CERTIFICATE_SIZE 79 int "Number of bytes to reserve for the extra certificate" 80 depends on SYSTEM_EXTRA_CERTIFICATE 81 default 4096 82 help 83 This is the number of bytes reserved in the kernel image for a 84 certificate to be inserted. 85 86config SECONDARY_TRUSTED_KEYRING 87 bool "Provide a keyring to which extra trustable keys may be added" 88 depends on SYSTEM_TRUSTED_KEYRING 89 help 90 If set, provide a keyring to which extra keys may be added, provided 91 those keys are not blacklisted and are vouched for by a key built 92 into the kernel or already in the secondary trusted keyring. 93 94config SYSTEM_BLACKLIST_KEYRING 95 bool "Provide system-wide ring of blacklisted keys" 96 depends on KEYS 97 help 98 Provide a system keyring to which blacklisted keys can be added. 99 Keys in the keyring are considered entirely untrusted. Keys in this 100 keyring are used by the module signature checking to reject loading 101 of modules signed with a blacklisted key. 102 103config SYSTEM_BLACKLIST_HASH_LIST 104 string "Hashes to be preloaded into the system blacklist keyring" 105 depends on SYSTEM_BLACKLIST_KEYRING 106 help 107 If set, this option should be the filename of a list of hashes in the 108 form "<hash>", "<hash>", ... . This will be included into a C 109 wrapper to incorporate the list into the kernel. Each <hash> should 110 be a string of hex digits. 111 112config SYSTEM_REVOCATION_LIST 113 bool "Provide system-wide ring of revocation certificates" 114 depends on SYSTEM_BLACKLIST_KEYRING 115 depends on PKCS7_MESSAGE_PARSER=y 116 help 117 If set, this allows revocation certificates to be stored in the 118 blacklist keyring and implements a hook whereby a PKCS#7 message can 119 be checked to see if it matches such a certificate. 120 121config SYSTEM_REVOCATION_KEYS 122 string "X.509 certificates to be preloaded into the system blacklist keyring" 123 depends on SYSTEM_REVOCATION_LIST 124 help 125 If set, this option should be the filename of a PEM-formatted file 126 containing X.509 certificates to be included in the default blacklist 127 keyring. 128 129endmenu 130