xref: /openbmc/linux/security/integrity/ima/Kconfig (revision 50df3be7)
1# SPDX-License-Identifier: GPL-2.0-only
2# IBM Integrity Measurement Architecture
3#
4config IMA
5	bool "Integrity Measurement Architecture(IMA)"
6	select SECURITYFS
7	select CRYPTO
8	select CRYPTO_HMAC
9	select CRYPTO_MD5
10	select CRYPTO_SHA1
11	select CRYPTO_HASH_INFO
12	select TCG_TPM if HAS_IOMEM && !UML
13	select TCG_TIS if TCG_TPM && X86
14	select TCG_CRB if TCG_TPM && ACPI
15	select TCG_IBMVTPM if TCG_TPM && PPC_PSERIES
16	select INTEGRITY_AUDIT if AUDIT
17	help
18	  The Trusted Computing Group(TCG) runtime Integrity
19	  Measurement Architecture(IMA) maintains a list of hash
20	  values of executables and other sensitive system files,
21	  as they are read or executed. If an attacker manages
22	  to change the contents of an important system file
23	  being measured, we can tell.
24
25	  If your system has a TPM chip, then IMA also maintains
26	  an aggregate integrity value over this list inside the
27	  TPM hardware, so that the TPM can prove to a third party
28	  whether or not critical system files have been modified.
29	  Read <http://www.usenix.org/events/sec04/tech/sailer.html>
30	  to learn more about IMA.
31	  If unsure, say N.
32
33config IMA_KEXEC
34	bool "Enable carrying the IMA measurement list across a soft boot"
35	depends on IMA && TCG_TPM && HAVE_IMA_KEXEC
36	default n
37	help
38	   TPM PCRs are only reset on a hard reboot.  In order to validate
39	   a TPM's quote after a soft boot, the IMA measurement list of the
40	   running kernel must be saved and restored on boot.
41
42	   Depending on the IMA policy, the measurement list can grow to
43	   be very large.
44
45config IMA_MEASURE_PCR_IDX
46	int
47	depends on IMA
48	range 8 14
49	default 10
50	help
51	  IMA_MEASURE_PCR_IDX determines the TPM PCR register index
52	  that IMA uses to maintain the integrity aggregate of the
53	  measurement list.  If unsure, use the default 10.
54
55config IMA_LSM_RULES
56	bool
57	depends on IMA && AUDIT && (SECURITY_SELINUX || SECURITY_SMACK)
58	default y
59	help
60	  Disabling this option will disregard LSM based policy rules.
61
62choice
63	prompt "Default template"
64	default IMA_NG_TEMPLATE
65	depends on IMA
66	help
67	  Select the default IMA measurement template.
68
69	  The original 'ima' measurement list template contains a
70	  hash, defined as 20 bytes, and a null terminated pathname,
71	  limited to 255 characters.  The 'ima-ng' measurement list
72	  template permits both larger hash digests and longer
73	  pathnames.
74
75	config IMA_TEMPLATE
76		bool "ima"
77	config IMA_NG_TEMPLATE
78		bool "ima-ng (default)"
79	config IMA_SIG_TEMPLATE
80		bool "ima-sig"
81endchoice
82
83config IMA_DEFAULT_TEMPLATE
84	string
85	depends on IMA
86	default "ima" if IMA_TEMPLATE
87	default "ima-ng" if IMA_NG_TEMPLATE
88	default "ima-sig" if IMA_SIG_TEMPLATE
89
90choice
91	prompt "Default integrity hash algorithm"
92	default IMA_DEFAULT_HASH_SHA1
93	depends on IMA
94	help
95	   Select the default hash algorithm used for the measurement
96	   list, integrity appraisal and audit log.  The compiled default
97	   hash algorithm can be overwritten using the kernel command
98	   line 'ima_hash=' option.
99
100	config IMA_DEFAULT_HASH_SHA1
101		bool "SHA1 (default)"
102		depends on CRYPTO_SHA1=y
103
104	config IMA_DEFAULT_HASH_SHA256
105		bool "SHA256"
106		depends on CRYPTO_SHA256=y && !IMA_TEMPLATE
107
108	config IMA_DEFAULT_HASH_SHA512
109		bool "SHA512"
110		depends on CRYPTO_SHA512=y && !IMA_TEMPLATE
111
112	config IMA_DEFAULT_HASH_WP512
113		bool "WP512"
114		depends on CRYPTO_WP512=y && !IMA_TEMPLATE
115endchoice
116
117config IMA_DEFAULT_HASH
118	string
119	depends on IMA
120	default "sha1" if IMA_DEFAULT_HASH_SHA1
121	default "sha256" if IMA_DEFAULT_HASH_SHA256
122	default "sha512" if IMA_DEFAULT_HASH_SHA512
123	default "wp512" if IMA_DEFAULT_HASH_WP512
124
125config IMA_WRITE_POLICY
126	bool "Enable multiple writes to the IMA policy"
127	depends on IMA
128	default n
129	help
130	  IMA policy can now be updated multiple times.  The new rules get
131	  appended to the original policy.  Have in mind that the rules are
132	  scanned in FIFO order so be careful when you design and add new ones.
133
134	  If unsure, say N.
135
136config IMA_READ_POLICY
137	bool "Enable reading back the current IMA policy"
138	depends on IMA
139	default y if IMA_WRITE_POLICY
140	default n if !IMA_WRITE_POLICY
141	help
142	   It is often useful to be able to read back the IMA policy.  It is
143	   even more important after introducing CONFIG_IMA_WRITE_POLICY.
144	   This option allows the root user to see the current policy rules.
145
146config IMA_APPRAISE
147	bool "Appraise integrity measurements"
148	depends on IMA
149	default n
150	help
151	  This option enables local measurement integrity appraisal.
152	  It requires the system to be labeled with a security extended
153	  attribute containing the file hash measurement.  To protect
154	  the security extended attributes from offline attack, enable
155	  and configure EVM.
156
157	  For more information on integrity appraisal refer to:
158	  <http://linux-ima.sourceforge.net>
159	  If unsure, say N.
160
161config IMA_ARCH_POLICY
162        bool "Enable loading an IMA architecture specific policy"
163        depends on (KEXEC_SIG && IMA) || IMA_APPRAISE \
164		   && INTEGRITY_ASYMMETRIC_KEYS
165        default n
166        help
167          This option enables loading an IMA architecture specific policy
168          based on run time secure boot flags.
169
170config IMA_APPRAISE_BUILD_POLICY
171	bool "IMA build time configured policy rules"
172	depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS
173	default n
174	help
175	  This option defines an IMA appraisal policy at build time, which
176	  is enforced at run time without having to specify a builtin
177	  policy name on the boot command line.  The build time appraisal
178	  policy rules persist after loading a custom policy.
179
180	  Depending on the rules configured, this policy may require kernel
181	  modules, firmware, the kexec kernel image, and/or the IMA policy
182	  to be signed.  Unsigned files might prevent the system from
183	  booting or applications from working properly.
184
185config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS
186	bool "Appraise firmware signatures"
187	depends on IMA_APPRAISE_BUILD_POLICY
188	default n
189	help
190	  This option defines a policy requiring all firmware to be signed,
191	  including the regulatory.db.  If both this option and
192	  CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature
193	  verification methods are necessary.
194
195config IMA_APPRAISE_REQUIRE_KEXEC_SIGS
196	bool "Appraise kexec kernel image signatures"
197	depends on IMA_APPRAISE_BUILD_POLICY
198	default n
199	help
200	  Enabling this rule will require all kexec'ed kernel images to
201	  be signed and verified by a public key on the trusted IMA
202	  keyring.
203
204	  Kernel image signatures can not be verified by the original
205	  kexec_load syscall.  Enabling this rule will prevent its
206	  usage.
207
208config IMA_APPRAISE_REQUIRE_MODULE_SIGS
209	bool "Appraise kernel modules signatures"
210	depends on IMA_APPRAISE_BUILD_POLICY
211	default n
212	help
213	  Enabling this rule will require all kernel modules to be signed
214	  and verified by a public key on the trusted IMA keyring.
215
216	  Kernel module signatures can only be verified by IMA-appraisal,
217	  via the finit_module syscall. Enabling this rule will prevent
218	  the usage of the init_module syscall.
219
220config IMA_APPRAISE_REQUIRE_POLICY_SIGS
221	bool "Appraise IMA policy signature"
222	depends on IMA_APPRAISE_BUILD_POLICY
223	default n
224	help
225	  Enabling this rule will require the IMA policy to be signed and
226	  and verified by a key on the trusted IMA keyring.
227
228config IMA_APPRAISE_BOOTPARAM
229	bool "ima_appraise boot parameter"
230	depends on IMA_APPRAISE && !IMA_ARCH_POLICY
231	default y
232	help
233	  This option enables the different "ima_appraise=" modes
234	  (eg. fix, log) from the boot command line.
235
236config IMA_APPRAISE_MODSIG
237	bool "Support module-style signatures for appraisal"
238	depends on IMA_APPRAISE
239	depends on INTEGRITY_ASYMMETRIC_KEYS
240	select PKCS7_MESSAGE_PARSER
241	select MODULE_SIG_FORMAT
242	default n
243	help
244	   Adds support for signatures appended to files. The format of the
245	   appended signature is the same used for signed kernel modules.
246	   The modsig keyword can be used in the IMA policy to allow a hook
247	   to accept such signatures.
248
249config IMA_TRUSTED_KEYRING
250	bool "Require all keys on the .ima keyring be signed (deprecated)"
251	depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
252	depends on INTEGRITY_ASYMMETRIC_KEYS
253	select INTEGRITY_TRUSTED_KEYRING
254	default y
255	help
256	   This option requires that all keys added to the .ima
257	   keyring be signed by a key on the system trusted keyring.
258
259	   This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING
260
261config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
262	bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
263	depends on SYSTEM_TRUSTED_KEYRING
264	depends on SECONDARY_TRUSTED_KEYRING
265	depends on INTEGRITY_ASYMMETRIC_KEYS
266	select INTEGRITY_TRUSTED_KEYRING
267	default n
268	help
269	  Keys may be added to the IMA or IMA blacklist keyrings, if the
270	  key is validly signed by a CA cert in the system built-in or
271	  secondary trusted keyrings.
272
273	  Intermediate keys between those the kernel has compiled in and the
274	  IMA keys to be added may be added to the system secondary keyring,
275	  provided they are validly signed by a key already resident in the
276	  built-in or secondary trusted keyrings.
277
278config IMA_BLACKLIST_KEYRING
279	bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)"
280	depends on SYSTEM_TRUSTED_KEYRING
281	depends on IMA_TRUSTED_KEYRING
282	default n
283	help
284	   This option creates an IMA blacklist keyring, which contains all
285	   revoked IMA keys.  It is consulted before any other keyring.  If
286	   the search is successful the requested operation is rejected and
287	   an error is returned to the caller.
288
289config IMA_LOAD_X509
290	bool "Load X509 certificate onto the '.ima' trusted keyring"
291	depends on IMA_TRUSTED_KEYRING
292	default n
293	help
294	   File signature verification is based on the public keys
295	   loaded on the .ima trusted keyring. These public keys are
296	   X509 certificates signed by a trusted key on the
297	   .system keyring.  This option enables X509 certificate
298	   loading from the kernel onto the '.ima' trusted keyring.
299
300config IMA_X509_PATH
301	string "IMA X509 certificate path"
302	depends on IMA_LOAD_X509
303	default "/etc/keys/x509_ima.der"
304	help
305	   This option defines IMA X509 certificate path.
306
307config IMA_APPRAISE_SIGNED_INIT
308	bool "Require signed user-space initialization"
309	depends on IMA_LOAD_X509
310	default n
311	help
312	   This option requires user-space init to be signed.
313