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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.