xref: /openbmc/linux/security/integrity/ima/Kconfig (revision a36954f5)
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_IBMVTPM if TCG_TPM && PPC_PSERIES
14	help
15	  The Trusted Computing Group(TCG) runtime Integrity
16	  Measurement Architecture(IMA) maintains a list of hash
17	  values of executables and other sensitive system files,
18	  as they are read or executed. If an attacker manages
19	  to change the contents of an important system file
20	  being measured, we can tell.
21
22	  If your system has a TPM chip, then IMA also maintains
23	  an aggregate integrity value over this list inside the
24	  TPM hardware, so that the TPM can prove to a third party
25	  whether or not critical system files have been modified.
26	  Read <http://www.usenix.org/events/sec04/tech/sailer.html>
27	  to learn more about IMA.
28	  If unsure, say N.
29
30config IMA_KEXEC
31	bool "Enable carrying the IMA measurement list across a soft boot"
32	depends on IMA && TCG_TPM && HAVE_IMA_KEXEC
33	default n
34	help
35	   TPM PCRs are only reset on a hard reboot.  In order to validate
36	   a TPM's quote after a soft boot, the IMA measurement list of the
37	   running kernel must be saved and restored on boot.
38
39	   Depending on the IMA policy, the measurement list can grow to
40	   be very large.
41
42config IMA_MEASURE_PCR_IDX
43	int
44	depends on IMA
45	range 8 14
46	default 10
47	help
48	  IMA_MEASURE_PCR_IDX determines the TPM PCR register index
49	  that IMA uses to maintain the integrity aggregate of the
50	  measurement list.  If unsure, use the default 10.
51
52config IMA_LSM_RULES
53	bool
54	depends on IMA && AUDIT && (SECURITY_SELINUX || SECURITY_SMACK)
55	default y
56	help
57	  Disabling this option will disregard LSM based policy rules.
58
59choice
60	prompt "Default template"
61	default IMA_NG_TEMPLATE
62	depends on IMA
63	help
64	  Select the default IMA measurement template.
65
66	  The original 'ima' measurement list template contains a
67	  hash, defined as 20 bytes, and a null terminated pathname,
68	  limited to 255 characters.  The 'ima-ng' measurement list
69	  template permits both larger hash digests and longer
70	  pathnames.
71
72	config IMA_TEMPLATE
73		bool "ima"
74	config IMA_NG_TEMPLATE
75		bool "ima-ng (default)"
76	config IMA_SIG_TEMPLATE
77		bool "ima-sig"
78endchoice
79
80config IMA_DEFAULT_TEMPLATE
81	string
82	depends on IMA
83	default "ima" if IMA_TEMPLATE
84	default "ima-ng" if IMA_NG_TEMPLATE
85	default "ima-sig" if IMA_SIG_TEMPLATE
86
87choice
88	prompt "Default integrity hash algorithm"
89	default IMA_DEFAULT_HASH_SHA1
90	depends on IMA
91	help
92	   Select the default hash algorithm used for the measurement
93	   list, integrity appraisal and audit log.  The compiled default
94	   hash algorithm can be overwritten using the kernel command
95	   line 'ima_hash=' option.
96
97	config IMA_DEFAULT_HASH_SHA1
98		bool "SHA1 (default)"
99		depends on CRYPTO_SHA1
100
101	config IMA_DEFAULT_HASH_SHA256
102		bool "SHA256"
103		depends on CRYPTO_SHA256 && !IMA_TEMPLATE
104
105	config IMA_DEFAULT_HASH_SHA512
106		bool "SHA512"
107		depends on CRYPTO_SHA512 && !IMA_TEMPLATE
108
109	config IMA_DEFAULT_HASH_WP512
110		bool "WP512"
111		depends on CRYPTO_WP512 && !IMA_TEMPLATE
112endchoice
113
114config IMA_DEFAULT_HASH
115	string
116	depends on IMA
117	default "sha1" if IMA_DEFAULT_HASH_SHA1
118	default "sha256" if IMA_DEFAULT_HASH_SHA256
119	default "sha512" if IMA_DEFAULT_HASH_SHA512
120	default "wp512" if IMA_DEFAULT_HASH_WP512
121
122config IMA_WRITE_POLICY
123	bool "Enable multiple writes to the IMA policy"
124	depends on IMA
125	default n
126	help
127	  IMA policy can now be updated multiple times.  The new rules get
128	  appended to the original policy.  Have in mind that the rules are
129	  scanned in FIFO order so be careful when you design and add new ones.
130
131	  If unsure, say N.
132
133config IMA_READ_POLICY
134	bool "Enable reading back the current IMA policy"
135	depends on IMA
136	default y if IMA_WRITE_POLICY
137	default n if !IMA_WRITE_POLICY
138	help
139	   It is often useful to be able to read back the IMA policy.  It is
140	   even more important after introducing CONFIG_IMA_WRITE_POLICY.
141	   This option allows the root user to see the current policy rules.
142
143config IMA_APPRAISE
144	bool "Appraise integrity measurements"
145	depends on IMA
146	default n
147	help
148	  This option enables local measurement integrity appraisal.
149	  It requires the system to be labeled with a security extended
150	  attribute containing the file hash measurement.  To protect
151	  the security extended attributes from offline attack, enable
152	  and configure EVM.
153
154	  For more information on integrity appraisal refer to:
155	  <http://linux-ima.sourceforge.net>
156	  If unsure, say N.
157
158config IMA_TRUSTED_KEYRING
159	bool "Require all keys on the .ima keyring be signed (deprecated)"
160	depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
161	depends on INTEGRITY_ASYMMETRIC_KEYS
162	select INTEGRITY_TRUSTED_KEYRING
163	default y
164	help
165	   This option requires that all keys added to the .ima
166	   keyring be signed by a key on the system trusted keyring.
167
168	   This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING
169
170config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
171	bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
172	depends on SYSTEM_TRUSTED_KEYRING
173	depends on SECONDARY_TRUSTED_KEYRING
174	depends on INTEGRITY_ASYMMETRIC_KEYS
175	select INTEGRITY_TRUSTED_KEYRING
176	default n
177	help
178	  Keys may be added to the IMA or IMA blacklist keyrings, if the
179	  key is validly signed by a CA cert in the system built-in or
180	  secondary trusted keyrings.
181
182	  Intermediate keys between those the kernel has compiled in and the
183	  IMA keys to be added may be added to the system secondary keyring,
184	  provided they are validly signed by a key already resident in the
185	  built-in or secondary trusted keyrings.
186
187config IMA_BLACKLIST_KEYRING
188	bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)"
189	depends on SYSTEM_TRUSTED_KEYRING
190	depends on IMA_TRUSTED_KEYRING
191	default n
192	help
193	   This option creates an IMA blacklist keyring, which contains all
194	   revoked IMA keys.  It is consulted before any other keyring.  If
195	   the search is successful the requested operation is rejected and
196	   an error is returned to the caller.
197
198config IMA_LOAD_X509
199	bool "Load X509 certificate onto the '.ima' trusted keyring"
200	depends on IMA_TRUSTED_KEYRING
201	default n
202	help
203	   File signature verification is based on the public keys
204	   loaded on the .ima trusted keyring. These public keys are
205	   X509 certificates signed by a trusted key on the
206	   .system keyring.  This option enables X509 certificate
207	   loading from the kernel onto the '.ima' trusted keyring.
208
209config IMA_X509_PATH
210	string "IMA X509 certificate path"
211	depends on IMA_LOAD_X509
212	default "/etc/keys/x509_ima.der"
213	help
214	   This option defines IMA X509 certificate path.
215
216config IMA_APPRAISE_SIGNED_INIT
217	bool "Require signed user-space initialization"
218	depends on IMA_LOAD_X509
219	default n
220	help
221	   This option requires user-space init to be signed.
222