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 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 32if IMA 33 34config IMA_KEXEC 35 bool "Enable carrying the IMA measurement list across a soft boot" 36 depends on TCG_TPM && HAVE_IMA_KEXEC 37 default n 38 help 39 TPM PCRs are only reset on a hard reboot. In order to validate 40 a TPM's quote after a soft boot, the IMA measurement list of the 41 running kernel must be saved and restored on boot. 42 43 Depending on the IMA policy, the measurement list can grow to 44 be very large. 45 46config IMA_MEASURE_PCR_IDX 47 int 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 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 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. The configured default template can be replaced 73 by specifying "ima_template=" on the boot command line. 74 75 config IMA_NG_TEMPLATE 76 bool "ima-ng (default)" 77 config IMA_SIG_TEMPLATE 78 bool "ima-sig" 79endchoice 80 81config IMA_DEFAULT_TEMPLATE 82 string 83 default "ima-ng" if IMA_NG_TEMPLATE 84 default "ima-sig" if IMA_SIG_TEMPLATE 85 86choice 87 prompt "Default integrity hash algorithm" 88 default IMA_DEFAULT_HASH_SHA1 89 help 90 Select the default hash algorithm used for the measurement 91 list, integrity appraisal and audit log. The compiled default 92 hash algorithm can be overwritten using the kernel command 93 line 'ima_hash=' option. 94 95 config IMA_DEFAULT_HASH_SHA1 96 bool "SHA1 (default)" 97 depends on CRYPTO_SHA1=y 98 99 config IMA_DEFAULT_HASH_SHA256 100 bool "SHA256" 101 depends on CRYPTO_SHA256=y 102 103 config IMA_DEFAULT_HASH_SHA512 104 bool "SHA512" 105 depends on CRYPTO_SHA512=y 106 107 config IMA_DEFAULT_HASH_WP512 108 bool "WP512" 109 depends on CRYPTO_WP512=y 110endchoice 111 112config IMA_DEFAULT_HASH 113 string 114 default "sha1" if IMA_DEFAULT_HASH_SHA1 115 default "sha256" if IMA_DEFAULT_HASH_SHA256 116 default "sha512" if IMA_DEFAULT_HASH_SHA512 117 default "wp512" if IMA_DEFAULT_HASH_WP512 118 119config IMA_WRITE_POLICY 120 bool "Enable multiple writes to the IMA policy" 121 default n 122 help 123 IMA policy can now be updated multiple times. The new rules get 124 appended to the original policy. Have in mind that the rules are 125 scanned in FIFO order so be careful when you design and add new ones. 126 127 If unsure, say N. 128 129config IMA_READ_POLICY 130 bool "Enable reading back the current IMA policy" 131 default y if IMA_WRITE_POLICY 132 default n if !IMA_WRITE_POLICY 133 help 134 It is often useful to be able to read back the IMA policy. It is 135 even more important after introducing CONFIG_IMA_WRITE_POLICY. 136 This option allows the root user to see the current policy rules. 137 138config IMA_APPRAISE 139 bool "Appraise integrity measurements" 140 default n 141 help 142 This option enables local measurement integrity appraisal. 143 It requires the system to be labeled with a security extended 144 attribute containing the file hash measurement. To protect 145 the security extended attributes from offline attack, enable 146 and configure EVM. 147 148 For more information on integrity appraisal refer to: 149 <http://linux-ima.sourceforge.net> 150 If unsure, say N. 151 152config IMA_ARCH_POLICY 153 bool "Enable loading an IMA architecture specific policy" 154 depends on (KEXEC_SIG && IMA) || IMA_APPRAISE \ 155 && INTEGRITY_ASYMMETRIC_KEYS 156 default n 157 help 158 This option enables loading an IMA architecture specific policy 159 based on run time secure boot flags. 160 161config IMA_APPRAISE_BUILD_POLICY 162 bool "IMA build time configured policy rules" 163 depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS 164 default n 165 help 166 This option defines an IMA appraisal policy at build time, which 167 is enforced at run time without having to specify a builtin 168 policy name on the boot command line. The build time appraisal 169 policy rules persist after loading a custom policy. 170 171 Depending on the rules configured, this policy may require kernel 172 modules, firmware, the kexec kernel image, and/or the IMA policy 173 to be signed. Unsigned files might prevent the system from 174 booting or applications from working properly. 175 176config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS 177 bool "Appraise firmware signatures" 178 depends on IMA_APPRAISE_BUILD_POLICY 179 default n 180 help 181 This option defines a policy requiring all firmware to be signed, 182 including the regulatory.db. If both this option and 183 CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature 184 verification methods are necessary. 185 186config IMA_APPRAISE_REQUIRE_KEXEC_SIGS 187 bool "Appraise kexec kernel image signatures" 188 depends on IMA_APPRAISE_BUILD_POLICY 189 default n 190 help 191 Enabling this rule will require all kexec'ed kernel images to 192 be signed and verified by a public key on the trusted IMA 193 keyring. 194 195 Kernel image signatures can not be verified by the original 196 kexec_load syscall. Enabling this rule will prevent its 197 usage. 198 199config IMA_APPRAISE_REQUIRE_MODULE_SIGS 200 bool "Appraise kernel modules signatures" 201 depends on IMA_APPRAISE_BUILD_POLICY 202 default n 203 help 204 Enabling this rule will require all kernel modules to be signed 205 and verified by a public key on the trusted IMA keyring. 206 207 Kernel module signatures can only be verified by IMA-appraisal, 208 via the finit_module syscall. Enabling this rule will prevent 209 the usage of the init_module syscall. 210 211config IMA_APPRAISE_REQUIRE_POLICY_SIGS 212 bool "Appraise IMA policy signature" 213 depends on IMA_APPRAISE_BUILD_POLICY 214 default n 215 help 216 Enabling this rule will require the IMA policy to be signed and 217 and verified by a key on the trusted IMA keyring. 218 219config IMA_APPRAISE_BOOTPARAM 220 bool "ima_appraise boot parameter" 221 depends on IMA_APPRAISE 222 default y 223 help 224 This option enables the different "ima_appraise=" modes 225 (eg. fix, log) from the boot command line. 226 227config IMA_APPRAISE_MODSIG 228 bool "Support module-style signatures for appraisal" 229 depends on IMA_APPRAISE 230 depends on INTEGRITY_ASYMMETRIC_KEYS 231 select PKCS7_MESSAGE_PARSER 232 select MODULE_SIG_FORMAT 233 default n 234 help 235 Adds support for signatures appended to files. The format of the 236 appended signature is the same used for signed kernel modules. 237 The modsig keyword can be used in the IMA policy to allow a hook 238 to accept such signatures. 239 240config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY 241 bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)" 242 depends on SYSTEM_TRUSTED_KEYRING 243 depends on SECONDARY_TRUSTED_KEYRING 244 depends on INTEGRITY_ASYMMETRIC_KEYS 245 select INTEGRITY_TRUSTED_KEYRING 246 default n 247 help 248 Keys may be added to the IMA or IMA blacklist keyrings, if the 249 key is validly signed by a CA cert in the system built-in or 250 secondary trusted keyrings. 251 252 Intermediate keys between those the kernel has compiled in and the 253 IMA keys to be added may be added to the system secondary keyring, 254 provided they are validly signed by a key already resident in the 255 built-in or secondary trusted keyrings. 256 257config IMA_BLACKLIST_KEYRING 258 bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)" 259 depends on SYSTEM_TRUSTED_KEYRING 260 depends on INTEGRITY_TRUSTED_KEYRING 261 default n 262 help 263 This option creates an IMA blacklist keyring, which contains all 264 revoked IMA keys. It is consulted before any other keyring. If 265 the search is successful the requested operation is rejected and 266 an error is returned to the caller. 267 268config IMA_LOAD_X509 269 bool "Load X509 certificate onto the '.ima' trusted keyring" 270 depends on INTEGRITY_TRUSTED_KEYRING 271 default n 272 help 273 File signature verification is based on the public keys 274 loaded on the .ima trusted keyring. These public keys are 275 X509 certificates signed by a trusted key on the 276 .system keyring. This option enables X509 certificate 277 loading from the kernel onto the '.ima' trusted keyring. 278 279config IMA_X509_PATH 280 string "IMA X509 certificate path" 281 depends on IMA_LOAD_X509 282 default "/etc/keys/x509_ima.der" 283 help 284 This option defines IMA X509 certificate path. 285 286config IMA_APPRAISE_SIGNED_INIT 287 bool "Require signed user-space initialization" 288 depends on IMA_LOAD_X509 289 default n 290 help 291 This option requires user-space init to be signed. 292 293endif 294