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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_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 <https://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 || SECURITY_APPARMOR)
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
114
115 config IMA_DEFAULT_HASH_SM3
116 bool "SM3"
117 depends on CRYPTO_SM3=y && !IMA_TEMPLATE
118endchoice
119
120config IMA_DEFAULT_HASH
121 string
122 depends on IMA
123 default "sha1" if IMA_DEFAULT_HASH_SHA1
124 default "sha256" if IMA_DEFAULT_HASH_SHA256
125 default "sha512" if IMA_DEFAULT_HASH_SHA512
126 default "wp512" if IMA_DEFAULT_HASH_WP512
127 default "sm3" if IMA_DEFAULT_HASH_SM3
128
129config IMA_WRITE_POLICY
130 bool "Enable multiple writes to the IMA policy"
131 depends on IMA
132 default n
133 help
134 IMA policy can now be updated multiple times. The new rules get
135 appended to the original policy. Have in mind that the rules are
136 scanned in FIFO order so be careful when you design and add new ones.
137
138 If unsure, say N.
139
140config IMA_READ_POLICY
141 bool "Enable reading back the current IMA policy"
142 depends on IMA
143 default y if IMA_WRITE_POLICY
144 default n if !IMA_WRITE_POLICY
145 help
146 It is often useful to be able to read back the IMA policy. It is
147 even more important after introducing CONFIG_IMA_WRITE_POLICY.
148 This option allows the root user to see the current policy rules.
149
150config IMA_APPRAISE
151 bool "Appraise integrity measurements"
152 depends on IMA
153 default n
154 help
155 This option enables local measurement integrity appraisal.
156 It requires the system to be labeled with a security extended
157 attribute containing the file hash measurement. To protect
158 the security extended attributes from offline attack, enable
159 and configure EVM.
160
161 For more information on integrity appraisal refer to:
162 <http://linux-ima.sourceforge.net>
163 If unsure, say N.
164
165config IMA_ARCH_POLICY
166 bool "Enable loading an IMA architecture specific policy"
167 depends on (KEXEC_SIG && IMA) || IMA_APPRAISE \
168 && INTEGRITY_ASYMMETRIC_KEYS
169 default n
170 help
171 This option enables loading an IMA architecture specific policy
172 based on run time secure boot flags.
173
174config IMA_APPRAISE_BUILD_POLICY
175 bool "IMA build time configured policy rules"
176 depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS
177 default n
178 help
179 This option defines an IMA appraisal policy at build time, which
180 is enforced at run time without having to specify a builtin
181 policy name on the boot command line. The build time appraisal
182 policy rules persist after loading a custom policy.
183
184 Depending on the rules configured, this policy may require kernel
185 modules, firmware, the kexec kernel image, and/or the IMA policy
186 to be signed. Unsigned files might prevent the system from
187 booting or applications from working properly.
188
189config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS
190 bool "Appraise firmware signatures"
191 depends on IMA_APPRAISE_BUILD_POLICY
192 default n
193 help
194 This option defines a policy requiring all firmware to be signed,
195 including the regulatory.db. If both this option and
196 CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature
197 verification methods are necessary.
198
199config IMA_APPRAISE_REQUIRE_KEXEC_SIGS
200 bool "Appraise kexec kernel image signatures"
201 depends on IMA_APPRAISE_BUILD_POLICY
202 default n
203 help
204 Enabling this rule will require all kexec'ed kernel images to
205 be signed and verified by a public key on the trusted IMA
206 keyring.
207
208 Kernel image signatures can not be verified by the original
209 kexec_load syscall. Enabling this rule will prevent its
210 usage.
211
212config IMA_APPRAISE_REQUIRE_MODULE_SIGS
213 bool "Appraise kernel modules signatures"
214 depends on IMA_APPRAISE_BUILD_POLICY
215 default n
216 help
217 Enabling this rule will require all kernel modules to be signed
218 and verified by a public key on the trusted IMA keyring.
219
220 Kernel module signatures can only be verified by IMA-appraisal,
221 via the finit_module syscall. Enabling this rule will prevent
222 the usage of the init_module syscall.
223
224config IMA_APPRAISE_REQUIRE_POLICY_SIGS
225 bool "Appraise IMA policy signature"
226 depends on IMA_APPRAISE_BUILD_POLICY
227 default n
228 help
229 Enabling this rule will require the IMA policy to be signed and
230 and verified by a key on the trusted IMA keyring.
231
232config IMA_APPRAISE_BOOTPARAM
233 bool "ima_appraise boot parameter"
234 depends on IMA_APPRAISE
235 default y
236 help
237 This option enables the different "ima_appraise=" modes
238 (eg. fix, log) from the boot command line.
239
240config IMA_APPRAISE_MODSIG
241 bool "Support module-style signatures for appraisal"
242 depends on IMA_APPRAISE
243 depends on INTEGRITY_ASYMMETRIC_KEYS
244 select PKCS7_MESSAGE_PARSER
245 select MODULE_SIG_FORMAT
246 default n
247 help
248 Adds support for signatures appended to files. The format of the
249 appended signature is the same used for signed kernel modules.
250 The modsig keyword can be used in the IMA policy to allow a hook
251 to accept such signatures.
252
253config IMA_TRUSTED_KEYRING
254 bool "Require all keys on the .ima keyring be signed (deprecated)"
255 depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
256 depends on INTEGRITY_ASYMMETRIC_KEYS
257 select INTEGRITY_TRUSTED_KEYRING
258 default y
259 help
260 This option requires that all keys added to the .ima
261 keyring be signed by a key on the system trusted keyring.
262
263 This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING
264
265config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
266 bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
267 depends on SYSTEM_TRUSTED_KEYRING
268 depends on SECONDARY_TRUSTED_KEYRING
269 depends on INTEGRITY_ASYMMETRIC_KEYS
270 select INTEGRITY_TRUSTED_KEYRING
271 default n
272 help
273 Keys may be added to the IMA or IMA blacklist keyrings, if the
274 key is validly signed by a CA cert in the system built-in or
275 secondary trusted keyrings.
276
277 Intermediate keys between those the kernel has compiled in and the
278 IMA keys to be added may be added to the system secondary keyring,
279 provided they are validly signed by a key already resident in the
280 built-in or secondary trusted keyrings.
281
282config IMA_BLACKLIST_KEYRING
283 bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)"
284 depends on SYSTEM_TRUSTED_KEYRING
285 depends on IMA_TRUSTED_KEYRING
286 default n
287 help
288 This option creates an IMA blacklist keyring, which contains all
289 revoked IMA keys. It is consulted before any other keyring. If
290 the search is successful the requested operation is rejected and
291 an error is returned to the caller.
292
293config IMA_LOAD_X509
294 bool "Load X509 certificate onto the '.ima' trusted keyring"
295 depends on IMA_TRUSTED_KEYRING
296 default n
297 help
298 File signature verification is based on the public keys
299 loaded on the .ima trusted keyring. These public keys are
300 X509 certificates signed by a trusted key on the
301 .system keyring. This option enables X509 certificate
302 loading from the kernel onto the '.ima' trusted keyring.
303
304config IMA_X509_PATH
305 string "IMA X509 certificate path"
306 depends on IMA_LOAD_X509
307 default "/etc/keys/x509_ima.der"
308 help
309 This option defines IMA X509 certificate path.
310
311config IMA_APPRAISE_SIGNED_INIT
312 bool "Require signed user-space initialization"
313 depends on IMA_LOAD_X509
314 default n
315 help
316 This option requires user-space init to be signed.
317
318config IMA_MEASURE_ASYMMETRIC_KEYS
319 bool
320 depends on IMA
321 depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE=y
322 default y
323
324config IMA_QUEUE_EARLY_BOOT_KEYS
325 bool
326 depends on IMA_MEASURE_ASYMMETRIC_KEYS
327 depends on SYSTEM_TRUSTED_KEYRING
328 default y
329
330config IMA_SECURE_AND_OR_TRUSTED_BOOT
331 bool
332 depends on IMA_ARCH_POLICY
333 help
334 This option is selected by architectures to enable secure and/or
335 trusted boot based on IMA runtime policies.
336
337config IMA_DISABLE_HTABLE
338 bool "Disable htable to allow measurement of duplicate records"
339 depends on IMA
340 default n
341 help
342 This option disables htable to allow measurement of duplicate records.