[thirdparty/linux.git] / certs / Kconfig

# SPDX-License-Identifier: GPL-2.0
menu "Certificates for signature checking"

config MODULE_SIG_KEY
	string "File name or PKCS#11 URI of module signing key"
	default "certs/signing_key.pem"
	depends on MODULE_SIG || (IMA_APPRAISE_MODSIG && MODULES)
	help
         Provide the file name of a private key/certificate in PEM format,
         or a PKCS#11 URI according to RFC7512. The file should contain, or
         the URI should identify, both the certificate and its corresponding
         private key.

         If this option is unchanged from its default "certs/signing_key.pem",
         then the kernel will automatically generate the private key and
         certificate as described in Documentation/admin-guide/module-signing.rst

choice
	prompt "Type of module signing key to be generated"
	depends on MODULE_SIG || (IMA_APPRAISE_MODSIG && MODULES)
	help
	 The type of module signing key type to generate. This option
	 does not apply if a #PKCS11 URI is used.

config MODULE_SIG_KEY_TYPE_RSA
	bool "RSA"
	help
	 Use an RSA key for module signing.

config MODULE_SIG_KEY_TYPE_ECDSA
	bool "ECDSA"
	select CRYPTO_ECDSA
	help
	 Use an elliptic curve key (NIST P384) for module signing. Consider
	 using a strong hash like sha256 or sha384 for hashing modules.

	 Note: Remove all ECDSA signing keys, e.g. certs/signing_key.pem,
	 when falling back to building Linux 5.14 and older kernels.

endchoice

config SYSTEM_TRUSTED_KEYRING
	bool "Provide system-wide ring of trusted keys"
	depends on KEYS
	depends on ASYMMETRIC_KEY_TYPE
	depends on X509_CERTIFICATE_PARSER = y
	help
	  Provide a system keyring to which trusted keys can be added.  Keys in
	  the keyring are considered to be trusted.  Keys may be added at will
	  by the kernel from compiled-in data and from hardware key stores, but
	  userspace may only add extra keys if those keys can be verified by
	  keys already in the keyring.

	  Keys in this keyring are used by module signature checking.

config SYSTEM_TRUSTED_KEYS
	string "Additional X.509 keys for default system keyring"
	depends on SYSTEM_TRUSTED_KEYRING
	help
	  If set, this option should be the filename of a PEM-formatted file
	  containing trusted X.509 certificates to be included in the default
	  system keyring. Any certificate used for module signing is implicitly
	  also trusted.

	  NOTE: If you previously provided keys for the system keyring in the
	  form of DER-encoded *.x509 files in the top-level build directory,
	  those are no longer used. You will need to set this option instead.

config SYSTEM_EXTRA_CERTIFICATE
	bool "Reserve area for inserting a certificate without recompiling"
	depends on SYSTEM_TRUSTED_KEYRING
	help
	  If set, space for an extra certificate will be reserved in the kernel
	  image. This allows introducing a trusted certificate to the default
	  system keyring without recompiling the kernel.

config SYSTEM_EXTRA_CERTIFICATE_SIZE
	int "Number of bytes to reserve for the extra certificate"
	depends on SYSTEM_EXTRA_CERTIFICATE
	default 4096
	help
	  This is the number of bytes reserved in the kernel image for a
	  certificate to be inserted.

config SECONDARY_TRUSTED_KEYRING
	bool "Provide a keyring to which extra trustable keys may be added"
	depends on SYSTEM_TRUSTED_KEYRING
	help
	  If set, provide a keyring to which extra keys may be added, provided
	  those keys are not blacklisted and are vouched for by a key built
	  into the kernel, machine keyring (if configured), or already in the
	  secondary trusted keyring.

config SECONDARY_TRUSTED_KEYRING_SIGNED_BY_BUILTIN
	bool "Only allow additional certs signed by keys on the builtin trusted keyring"
	depends on SECONDARY_TRUSTED_KEYRING
	help
	  If set, only certificates signed by keys on the builtin trusted
	  keyring may be loaded onto the secondary trusted keyring.

	  Note: The machine keyring, if configured, will be linked to the
	  secondary keyring.  When enabling this option, it is recommended
	  to also configure INTEGRITY_CA_MACHINE_KEYRING_MAX to prevent
	  linking code signing keys with imputed trust to the secondary
	  trusted keyring.

config SYSTEM_BLACKLIST_KEYRING
	bool "Provide system-wide ring of blacklisted keys"
	depends on KEYS
	help
	  Provide a system keyring to which blacklisted keys can be added.
	  Keys in the keyring are considered entirely untrusted.  Keys in this
	  keyring are used by the module signature checking to reject loading
	  of modules signed with a blacklisted key.

config SYSTEM_BLACKLIST_HASH_LIST
	string "Hashes to be preloaded into the system blacklist keyring"
	depends on SYSTEM_BLACKLIST_KEYRING
	help
	  If set, this option should be the filename of a list of hashes in the
	  form "<hash>", "<hash>", ... .  This will be included into a C
	  wrapper to incorporate the list into the kernel.  Each <hash> must be a
	  string starting with a prefix ("tbs" or "bin"), then a colon (":"), and
	  finally an even number of hexadecimal lowercase characters (up to 128).
	  Certificate hashes can be generated with
	  tools/certs/print-cert-tbs-hash.sh .

config SYSTEM_REVOCATION_LIST
	bool "Provide system-wide ring of revocation certificates"
	depends on SYSTEM_BLACKLIST_KEYRING
	depends on PKCS7_MESSAGE_PARSER=y
	help
	  If set, this allows revocation certificates to be stored in the
	  blacklist keyring and implements a hook whereby a PKCS#7 message can
	  be checked to see if it matches such a certificate.

config SYSTEM_REVOCATION_KEYS
	string "X.509 certificates to be preloaded into the system blacklist keyring"
	depends on SYSTEM_REVOCATION_LIST
	help
	  If set, this option should be the filename of a PEM-formatted file
	  containing X.509 certificates to be included in the default blacklist
	  keyring.

config SYSTEM_BLACKLIST_AUTH_UPDATE
	bool "Allow root to add signed blacklist keys"
	depends on SYSTEM_BLACKLIST_KEYRING
	depends on SYSTEM_DATA_VERIFICATION
	help
	  If set, provide the ability to load new blacklist keys at run time if
	  they are signed and vouched by a certificate from the builtin trusted
	  keyring.  The PKCS#7 signature of the description is set in the key
	  payload.  Blacklist keys cannot be removed.

endmenu
Commit	Line	Data
b2441318	1	# SPDX-License-Identifier: GPL-2.0
cfc411e7 DH	2	menu "Certificates for signature checking"
	3
	4	config MODULE_SIG_KEY
	5	string "File name or PKCS#11 URI of module signing key"
	6	default "certs/signing_key.pem"
781a5739	7	depends on MODULE_SIG \|\| (IMA_APPRAISE_MODSIG && MODULES)
cfc411e7 DH	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
5fb94e9c	16	certificate as described in Documentation/admin-guide/module-signing.rst
cfc411e7	17
a4aed36e SB	18	choice
a4aed36e SB	19	prompt "Type of module signing key to be generated"
be0d5fa7	20	depends on MODULE_SIG \|\| (IMA_APPRAISE_MODSIG && MODULES)
a4aed36e SB	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
	25	config MODULE_SIG_KEY_TYPE_RSA
	26	bool "RSA"
a4aed36e SB	27	help
	28	Use an RSA key for module signing.
	29
	30	config MODULE_SIG_KEY_TYPE_ECDSA
	31	bool "ECDSA"
	32	select CRYPTO_ECDSA
a4aed36e SB	33	help
	34	Use an elliptic curve key (NIST P384) for module signing. Consider
	35	using a strong hash like sha256 or sha384 for hashing modules.
	36
	37	Note: Remove all ECDSA signing keys, e.g. certs/signing_key.pem,
	38	when falling back to building Linux 5.14 and older kernels.
	39
	40	endchoice
	41
cfc411e7 DH	42	config SYSTEM_TRUSTED_KEYRING
	43	bool "Provide system-wide ring of trusted keys"
	44	depends on KEYS
99716b7c	45	depends on ASYMMETRIC_KEY_TYPE
2154aca2	46	depends on X509_CERTIFICATE_PARSER = y
cfc411e7 DH	47	help
	48	Provide a system keyring to which trusted keys can be added. Keys in
	49	the keyring are considered to be trusted. Keys may be added at will
	50	by the kernel from compiled-in data and from hardware key stores, but
	51	userspace may only add extra keys if those keys can be verified by
	52	keys already in the keyring.
	53
	54	Keys in this keyring are used by module signature checking.
	55
	56	config SYSTEM_TRUSTED_KEYS
	57	string "Additional X.509 keys for default system keyring"
	58	depends on SYSTEM_TRUSTED_KEYRING
	59	help
	60	If set, this option should be the filename of a PEM-formatted file
	61	containing trusted X.509 certificates to be included in the default
	62	system keyring. Any certificate used for module signing is implicitly
	63	also trusted.
	64
	65	NOTE: If you previously provided keys for the system keyring in the
	66	form of DER-encoded *.x509 files in the top-level build directory,
	67	those are no longer used. You will need to set this option instead.
	68
c4c36105 MK	69	config SYSTEM_EXTRA_CERTIFICATE
	70	bool "Reserve area for inserting a certificate without recompiling"
	71	depends on SYSTEM_TRUSTED_KEYRING
	72	help
	73	If set, space for an extra certificate will be reserved in the kernel
	74	image. This allows introducing a trusted certificate to the default
	75	system keyring without recompiling the kernel.
	76
	77	config SYSTEM_EXTRA_CERTIFICATE_SIZE
	78	int "Number of bytes to reserve for the extra certificate"
	79	depends on SYSTEM_EXTRA_CERTIFICATE
	80	default 4096
	81	help
	82	This is the number of bytes reserved in the kernel image for a
	83	certificate to be inserted.
	84
d3bfe841 DH	85	config SECONDARY_TRUSTED_KEYRING
	86	bool "Provide a keyring to which extra trustable keys may be added"
	87	depends on SYSTEM_TRUSTED_KEYRING
	88	help
	89	If set, provide a keyring to which extra keys may be added, provided
	90	those keys are not blacklisted and are vouched for by a key built
b4650306 MZ	91	into the kernel, machine keyring (if configured), or already in the
	92	secondary trusted keyring.
	93
	94	config SECONDARY_TRUSTED_KEYRING_SIGNED_BY_BUILTIN
	95	bool "Only allow additional certs signed by keys on the builtin trusted keyring"
	96	depends on SECONDARY_TRUSTED_KEYRING
	97	help
	98	If set, only certificates signed by keys on the builtin trusted
	99	keyring may be loaded onto the secondary trusted keyring.
	100
	101	Note: The machine keyring, if configured, will be linked to the
	102	secondary keyring. When enabling this option, it is recommended
	103	to also configure INTEGRITY_CA_MACHINE_KEYRING_MAX to prevent
	104	linking code signing keys with imputed trust to the secondary
	105	trusted keyring.
d3bfe841	106
734114f8 DH	107	config SYSTEM_BLACKLIST_KEYRING
	108	bool "Provide system-wide ring of blacklisted keys"
	109	depends on KEYS
	110	help
	111	Provide a system keyring to which blacklisted keys can be added.
	112	Keys in the keyring are considered entirely untrusted. Keys in this
	113	keyring are used by the module signature checking to reject loading
	114	of modules signed with a blacklisted key.
	115
	116	config SYSTEM_BLACKLIST_HASH_LIST
	117	string "Hashes to be preloaded into the system blacklist keyring"
	118	depends on SYSTEM_BLACKLIST_KEYRING
	119	help
	120	If set, this option should be the filename of a list of hashes in the
	121	form "<hash>", "<hash>", ... . This will be included into a C
addf4663 MS	122	wrapper to incorporate the list into the kernel. Each <hash> must be a
	123	string starting with a prefix ("tbs" or "bin"), then a colon (":"), and
	124	finally an even number of hexadecimal lowercase characters (up to 128).
	125	Certificate hashes can be generated with
	126	tools/certs/print-cert-tbs-hash.sh .
734114f8	127
56c58126 ES	128	config SYSTEM_REVOCATION_LIST
	129	bool "Provide system-wide ring of revocation certificates"
	130	depends on SYSTEM_BLACKLIST_KEYRING
	131	depends on PKCS7_MESSAGE_PARSER=y
	132	help
	133	If set, this allows revocation certificates to be stored in the
	134	blacklist keyring and implements a hook whereby a PKCS#7 message can
	135	be checked to see if it matches such a certificate.
	136
d1f04410 ES	137	config SYSTEM_REVOCATION_KEYS
	138	string "X.509 certificates to be preloaded into the system blacklist keyring"
	139	depends on SYSTEM_REVOCATION_LIST
	140	help
	141	If set, this option should be the filename of a PEM-formatted file
	142	containing X.509 certificates to be included in the default blacklist
	143	keyring.
	144
6364d106 MS	145	config SYSTEM_BLACKLIST_AUTH_UPDATE
	146	bool "Allow root to add signed blacklist keys"
	147	depends on SYSTEM_BLACKLIST_KEYRING
	148	depends on SYSTEM_DATA_VERIFICATION
	149	help
	150	If set, provide the ability to load new blacklist keys at run time if
	151	they are signed and vouched by a certificate from the builtin trusted
	152	keyring. The PKCS#7 signature of the description is set in the key
	153	payload. Blacklist keys cannot be removed.
	154
cfc411e7	155	endmenu