xref: /openbmc/linux/security/integrity/ima/Kconfig (revision 023e4163)
1# IBM Integrity Measurement Architecture
2#
3config IMA
4	bool "Integrity Measurement Architecture(IMA)"
5	select SECURITYFS
6	select CRYPTO
7	select CRYPTO_HMAC
8	select CRYPTO_MD5
9	select CRYPTO_SHA1
10	select CRYPTO_HASH_INFO
11	select TCG_TPM if HAS_IOMEM && !UML
12	select TCG_TIS if TCG_TPM && X86
13	select TCG_CRB if TCG_TPM && ACPI
14	select TCG_IBMVTPM if TCG_TPM && PPC_PSERIES
15	select INTEGRITY_AUDIT if AUDIT
16	help
17	  The Trusted Computing Group(TCG) runtime Integrity
18	  Measurement Architecture(IMA) maintains a list of hash
19	  values of executables and other sensitive system files,
20	  as they are read or executed. If an attacker manages
21	  to change the contents of an important system file
22	  being measured, we can tell.
23
24	  If your system has a TPM chip, then IMA also maintains
25	  an aggregate integrity value over this list inside the
26	  TPM hardware, so that the TPM can prove to a third party
27	  whether or not critical system files have been modified.
28	  Read <http://www.usenix.org/events/sec04/tech/sailer.html>
29	  to learn more about IMA.
30	  If unsure, say N.
31
32config IMA_KEXEC
33	bool "Enable carrying the IMA measurement list across a soft boot"
34	depends on IMA && TCG_TPM && HAVE_IMA_KEXEC
35	default n
36	help
37	   TPM PCRs are only reset on a hard reboot.  In order to validate
38	   a TPM's quote after a soft boot, the IMA measurement list of the
39	   running kernel must be saved and restored on boot.
40
41	   Depending on the IMA policy, the measurement list can grow to
42	   be very large.
43
44config IMA_MEASURE_PCR_IDX
45	int
46	depends on IMA
47	range 8 14
48	default 10
49	help
50	  IMA_MEASURE_PCR_IDX determines the TPM PCR register index
51	  that IMA uses to maintain the integrity aggregate of the
52	  measurement list.  If unsure, use the default 10.
53
54config IMA_LSM_RULES
55	bool
56	depends on IMA && AUDIT && (SECURITY_SELINUX || SECURITY_SMACK)
57	default y
58	help
59	  Disabling this option will disregard LSM based policy rules.
60
61choice
62	prompt "Default template"
63	default IMA_NG_TEMPLATE
64	depends on IMA
65	help
66	  Select the default IMA measurement template.
67
68	  The original 'ima' measurement list template contains a
69	  hash, defined as 20 bytes, and a null terminated pathname,
70	  limited to 255 characters.  The 'ima-ng' measurement list
71	  template permits both larger hash digests and longer
72	  pathnames.
73
74	config IMA_TEMPLATE
75		bool "ima"
76	config IMA_NG_TEMPLATE
77		bool "ima-ng (default)"
78	config IMA_SIG_TEMPLATE
79		bool "ima-sig"
80endchoice
81
82config IMA_DEFAULT_TEMPLATE
83	string
84	depends on IMA
85	default "ima" if IMA_TEMPLATE
86	default "ima-ng" if IMA_NG_TEMPLATE
87	default "ima-sig" if IMA_SIG_TEMPLATE
88
89choice
90	prompt "Default integrity hash algorithm"
91	default IMA_DEFAULT_HASH_SHA1
92	depends on IMA
93	help
94	   Select the default hash algorithm used for the measurement
95	   list, integrity appraisal and audit log.  The compiled default
96	   hash algorithm can be overwritten using the kernel command
97	   line 'ima_hash=' option.
98
99	config IMA_DEFAULT_HASH_SHA1
100		bool "SHA1 (default)"
101		depends on CRYPTO_SHA1=y
102
103	config IMA_DEFAULT_HASH_SHA256
104		bool "SHA256"
105		depends on CRYPTO_SHA256=y && !IMA_TEMPLATE
106
107	config IMA_DEFAULT_HASH_SHA512
108		bool "SHA512"
109		depends on CRYPTO_SHA512=y && !IMA_TEMPLATE
110
111	config IMA_DEFAULT_HASH_WP512
112		bool "WP512"
113		depends on CRYPTO_WP512=y && !IMA_TEMPLATE
114endchoice
115
116config IMA_DEFAULT_HASH
117	string
118	depends on IMA
119	default "sha1" if IMA_DEFAULT_HASH_SHA1
120	default "sha256" if IMA_DEFAULT_HASH_SHA256
121	default "sha512" if IMA_DEFAULT_HASH_SHA512
122	default "wp512" if IMA_DEFAULT_HASH_WP512
123
124config IMA_WRITE_POLICY
125	bool "Enable multiple writes to the IMA policy"
126	depends on IMA
127	default n
128	help
129	  IMA policy can now be updated multiple times.  The new rules get
130	  appended to the original policy.  Have in mind that the rules are
131	  scanned in FIFO order so be careful when you design and add new ones.
132
133	  If unsure, say N.
134
135config IMA_READ_POLICY
136	bool "Enable reading back the current IMA policy"
137	depends on IMA
138	default y if IMA_WRITE_POLICY
139	default n if !IMA_WRITE_POLICY
140	help
141	   It is often useful to be able to read back the IMA policy.  It is
142	   even more important after introducing CONFIG_IMA_WRITE_POLICY.
143	   This option allows the root user to see the current policy rules.
144
145config IMA_APPRAISE
146	bool "Appraise integrity measurements"
147	depends on IMA
148	default n
149	help
150	  This option enables local measurement integrity appraisal.
151	  It requires the system to be labeled with a security extended
152	  attribute containing the file hash measurement.  To protect
153	  the security extended attributes from offline attack, enable
154	  and configure EVM.
155
156	  For more information on integrity appraisal refer to:
157	  <http://linux-ima.sourceforge.net>
158	  If unsure, say N.
159
160config IMA_ARCH_POLICY
161        bool "Enable loading an IMA architecture specific policy"
162        depends on KEXEC_VERIFY_SIG || IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS
163        default n
164        help
165          This option enables loading an IMA architecture specific policy
166          based on run time secure boot flags.
167
168config IMA_APPRAISE_BUILD_POLICY
169	bool "IMA build time configured policy rules"
170	depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS
171	default n
172	help
173	  This option defines an IMA appraisal policy at build time, which
174	  is enforced at run time without having to specify a builtin
175	  policy name on the boot command line.  The build time appraisal
176	  policy rules persist after loading a custom policy.
177
178	  Depending on the rules configured, this policy may require kernel
179	  modules, firmware, the kexec kernel image, and/or the IMA policy
180	  to be signed.  Unsigned files might prevent the system from
181	  booting or applications from working properly.
182
183config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS
184	bool "Appraise firmware signatures"
185	depends on IMA_APPRAISE_BUILD_POLICY
186	default n
187	help
188	  This option defines a policy requiring all firmware to be signed,
189	  including the regulatory.db.  If both this option and
190	  CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature
191	  verification methods are necessary.
192
193config IMA_APPRAISE_REQUIRE_KEXEC_SIGS
194	bool "Appraise kexec kernel image signatures"
195	depends on IMA_APPRAISE_BUILD_POLICY
196	default n
197	help
198	  Enabling this rule will require all kexec'ed kernel images to
199	  be signed and verified by a public key on the trusted IMA
200	  keyring.
201
202	  Kernel image signatures can not be verified by the original
203	  kexec_load syscall.  Enabling this rule will prevent its
204	  usage.
205
206config IMA_APPRAISE_REQUIRE_MODULE_SIGS
207	bool "Appraise kernel modules signatures"
208	depends on IMA_APPRAISE_BUILD_POLICY
209	default n
210	help
211	  Enabling this rule will require all kernel modules to be signed
212	  and verified by a public key on the trusted IMA keyring.
213
214	  Kernel module signatures can only be verified by IMA-appraisal,
215	  via the finit_module syscall. Enabling this rule will prevent
216	  the usage of the init_module syscall.
217
218config IMA_APPRAISE_REQUIRE_POLICY_SIGS
219	bool "Appraise IMA policy signature"
220	depends on IMA_APPRAISE_BUILD_POLICY
221	default n
222	help
223	  Enabling this rule will require the IMA policy to be signed and
224	  and verified by a key on the trusted IMA keyring.
225
226config IMA_APPRAISE_BOOTPARAM
227	bool "ima_appraise boot parameter"
228	depends on IMA_APPRAISE && !IMA_ARCH_POLICY
229	default y
230	help
231	  This option enables the different "ima_appraise=" modes
232	  (eg. fix, log) from the boot command line.
233
234config IMA_TRUSTED_KEYRING
235	bool "Require all keys on the .ima keyring be signed (deprecated)"
236	depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
237	depends on INTEGRITY_ASYMMETRIC_KEYS
238	select INTEGRITY_TRUSTED_KEYRING
239	default y
240	help
241	   This option requires that all keys added to the .ima
242	   keyring be signed by a key on the system trusted keyring.
243
244	   This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING
245
246config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
247	bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
248	depends on SYSTEM_TRUSTED_KEYRING
249	depends on SECONDARY_TRUSTED_KEYRING
250	depends on INTEGRITY_ASYMMETRIC_KEYS
251	select INTEGRITY_TRUSTED_KEYRING
252	default n
253	help
254	  Keys may be added to the IMA or IMA blacklist keyrings, if the
255	  key is validly signed by a CA cert in the system built-in or
256	  secondary trusted keyrings.
257
258	  Intermediate keys between those the kernel has compiled in and the
259	  IMA keys to be added may be added to the system secondary keyring,
260	  provided they are validly signed by a key already resident in the
261	  built-in or secondary trusted keyrings.
262
263config IMA_BLACKLIST_KEYRING
264	bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)"
265	depends on SYSTEM_TRUSTED_KEYRING
266	depends on IMA_TRUSTED_KEYRING
267	default n
268	help
269	   This option creates an IMA blacklist keyring, which contains all
270	   revoked IMA keys.  It is consulted before any other keyring.  If
271	   the search is successful the requested operation is rejected and
272	   an error is returned to the caller.
273
274config IMA_LOAD_X509
275	bool "Load X509 certificate onto the '.ima' trusted keyring"
276	depends on IMA_TRUSTED_KEYRING
277	default n
278	help
279	   File signature verification is based on the public keys
280	   loaded on the .ima trusted keyring. These public keys are
281	   X509 certificates signed by a trusted key on the
282	   .system keyring.  This option enables X509 certificate
283	   loading from the kernel onto the '.ima' trusted keyring.
284
285config IMA_X509_PATH
286	string "IMA X509 certificate path"
287	depends on IMA_LOAD_X509
288	default "/etc/keys/x509_ima.der"
289	help
290	   This option defines IMA X509 certificate path.
291
292config IMA_APPRAISE_SIGNED_INIT
293	bool "Require signed user-space initialization"
294	depends on IMA_LOAD_X509
295	default n
296	help
297	   This option requires user-space init to be signed.
298