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 SECURITY_PATH 12 select TCG_TPM if HAS_IOMEM 13 select TCG_TIS if TCG_TPM && X86 14 select TCG_CRB if TCG_TPM && ACPI 15 select TCG_IBMVTPM if TCG_TPM && PPC_PSERIES 16 select INTEGRITY_AUDIT if AUDIT 17 help 18 The Trusted Computing Group(TCG) runtime Integrity 19 Measurement Architecture(IMA) maintains a list of hash 20 values of executables and other sensitive system files, 21 as they are read or executed. If an attacker manages 22 to change the contents of an important system file 23 being measured, we can tell. 24 25 If your system has a TPM chip, then IMA also maintains 26 an aggregate integrity value over this list inside the 27 TPM hardware, so that the TPM can prove to a third party 28 whether or not critical system files have been modified. 29 Read <https://www.usenix.org/events/sec04/tech/sailer.html> 30 to learn more about IMA. 31 If unsure, say N. 32 33if IMA 34 35config IMA_KEXEC 36 bool "Enable carrying the IMA measurement list across a soft boot" 37 depends on TCG_TPM && HAVE_IMA_KEXEC 38 default n 39 help 40 TPM PCRs are only reset on a hard reboot. In order to validate 41 a TPM's quote after a soft boot, the IMA measurement list of the 42 running kernel must be saved and restored on boot. 43 44 Depending on the IMA policy, the measurement list can grow to 45 be very large. 46 47config IMA_MEASURE_PCR_IDX 48 int 49 range 8 14 50 default 10 51 help 52 IMA_MEASURE_PCR_IDX determines the TPM PCR register index 53 that IMA uses to maintain the integrity aggregate of the 54 measurement list. If unsure, use the default 10. 55 56config IMA_LSM_RULES 57 bool 58 depends on AUDIT && (SECURITY_SELINUX || SECURITY_SMACK || SECURITY_APPARMOR) 59 default y 60 help 61 Disabling this option will disregard LSM based policy rules. 62 63choice 64 prompt "Default template" 65 default IMA_NG_TEMPLATE 66 help 67 Select the default IMA measurement template. 68 69 The original 'ima' measurement list template contains a 70 hash, defined as 20 bytes, and a null terminated pathname, 71 limited to 255 characters. The 'ima-ng' measurement list 72 template permits both larger hash digests and longer 73 pathnames. The configured default template can be replaced 74 by specifying "ima_template=" on the boot command line. 75 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 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 help 91 Select the default hash algorithm used for the measurement 92 list, integrity appraisal and audit log. The compiled default 93 hash algorithm can be overwritten using the kernel command 94 line 'ima_hash=' option. 95 96 config IMA_DEFAULT_HASH_SHA1 97 bool "SHA1 (default)" 98 depends on CRYPTO_SHA1=y 99 100 config IMA_DEFAULT_HASH_SHA256 101 bool "SHA256" 102 depends on CRYPTO_SHA256=y 103 104 config IMA_DEFAULT_HASH_SHA512 105 bool "SHA512" 106 depends on CRYPTO_SHA512=y 107 108 config IMA_DEFAULT_HASH_WP512 109 bool "WP512" 110 depends on CRYPTO_WP512=y 111 112 config IMA_DEFAULT_HASH_SM3 113 bool "SM3" 114 depends on CRYPTO_SM3_GENERIC=y 115endchoice 116 117config IMA_DEFAULT_HASH 118 string 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 default "sm3" if IMA_DEFAULT_HASH_SM3 124 125config IMA_WRITE_POLICY 126 bool "Enable multiple writes to the IMA policy" 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 default y if IMA_WRITE_POLICY 138 default n if !IMA_WRITE_POLICY 139 help 140 It is often useful to be able to read back the IMA policy. It is 141 even more important after introducing CONFIG_IMA_WRITE_POLICY. 142 This option allows the root user to see the current policy rules. 143 144config IMA_APPRAISE 145 bool "Appraise integrity measurements" 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_ARCH_POLICY 159 bool "Enable loading an IMA architecture specific policy" 160 depends on (KEXEC_SIG && IMA) || IMA_APPRAISE \ 161 && INTEGRITY_ASYMMETRIC_KEYS 162 default n 163 help 164 This option enables loading an IMA architecture specific policy 165 based on run time secure boot flags. 166 167config IMA_APPRAISE_BUILD_POLICY 168 bool "IMA build time configured policy rules" 169 depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS 170 default n 171 help 172 This option defines an IMA appraisal policy at build time, which 173 is enforced at run time without having to specify a builtin 174 policy name on the boot command line. The build time appraisal 175 policy rules persist after loading a custom policy. 176 177 Depending on the rules configured, this policy may require kernel 178 modules, firmware, the kexec kernel image, and/or the IMA policy 179 to be signed. Unsigned files might prevent the system from 180 booting or applications from working properly. 181 182config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS 183 bool "Appraise firmware signatures" 184 depends on IMA_APPRAISE_BUILD_POLICY 185 default n 186 help 187 This option defines a policy requiring all firmware to be signed, 188 including the regulatory.db. If both this option and 189 CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature 190 verification methods are necessary. 191 192config IMA_APPRAISE_REQUIRE_KEXEC_SIGS 193 bool "Appraise kexec kernel image signatures" 194 depends on IMA_APPRAISE_BUILD_POLICY 195 default n 196 help 197 Enabling this rule will require all kexec'ed kernel images to 198 be signed and verified by a public key on the trusted IMA 199 keyring. 200 201 Kernel image signatures can not be verified by the original 202 kexec_load syscall. Enabling this rule will prevent its 203 usage. 204 205config IMA_APPRAISE_REQUIRE_MODULE_SIGS 206 bool "Appraise kernel modules signatures" 207 depends on IMA_APPRAISE_BUILD_POLICY 208 default n 209 help 210 Enabling this rule will require all kernel modules to be signed 211 and verified by a public key on the trusted IMA keyring. 212 213 Kernel module signatures can only be verified by IMA-appraisal, 214 via the finit_module syscall. Enabling this rule will prevent 215 the usage of the init_module syscall. 216 217config IMA_APPRAISE_REQUIRE_POLICY_SIGS 218 bool "Appraise IMA policy signature" 219 depends on IMA_APPRAISE_BUILD_POLICY 220 default n 221 help 222 Enabling this rule will require the IMA policy to be signed and 223 and verified by a key on the trusted IMA keyring. 224 225config IMA_APPRAISE_BOOTPARAM 226 bool "ima_appraise boot parameter" 227 depends on IMA_APPRAISE 228 default y 229 help 230 This option enables the different "ima_appraise=" modes 231 (eg. fix, log) from the boot command line. 232 233config IMA_APPRAISE_MODSIG 234 bool "Support module-style signatures for appraisal" 235 depends on IMA_APPRAISE 236 depends on INTEGRITY_ASYMMETRIC_KEYS 237 select PKCS7_MESSAGE_PARSER 238 select MODULE_SIG_FORMAT 239 default n 240 help 241 Adds support for signatures appended to files. The format of the 242 appended signature is the same used for signed kernel modules. 243 The modsig keyword can be used in the IMA policy to allow a hook 244 to accept such signatures. 245 246config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY 247 bool "Permit keys validly signed by a built-in, machine (if configured) or secondary" 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, 256 machine (if configured), or secondary trusted keyrings. The 257 key must also have the digitalSignature usage set. 258 259 Intermediate keys between those the kernel has compiled in and the 260 IMA keys to be added may be added to the system secondary keyring, 261 provided they are validly signed by a key already resident in the 262 built-in, machine (if configured) or secondary trusted keyrings. 263 264config IMA_BLACKLIST_KEYRING 265 bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)" 266 depends on SYSTEM_TRUSTED_KEYRING 267 depends on INTEGRITY_TRUSTED_KEYRING 268 default n 269 help 270 This option creates an IMA blacklist keyring, which contains all 271 revoked IMA keys. It is consulted before any other keyring. If 272 the search is successful the requested operation is rejected and 273 an error is returned to the caller. 274 275config IMA_LOAD_X509 276 bool "Load X509 certificate onto the '.ima' trusted keyring" 277 depends on INTEGRITY_TRUSTED_KEYRING 278 default n 279 help 280 File signature verification is based on the public keys 281 loaded on the .ima trusted keyring. These public keys are 282 X509 certificates signed by a trusted key on the 283 .system keyring. This option enables X509 certificate 284 loading from the kernel onto the '.ima' trusted keyring. 285 286config IMA_X509_PATH 287 string "IMA X509 certificate path" 288 depends on IMA_LOAD_X509 289 default "/etc/keys/x509_ima.der" 290 help 291 This option defines IMA X509 certificate path. 292 293config IMA_APPRAISE_SIGNED_INIT 294 bool "Require signed user-space initialization" 295 depends on IMA_LOAD_X509 296 default n 297 help 298 This option requires user-space init to be signed. 299 300config IMA_MEASURE_ASYMMETRIC_KEYS 301 bool 302 depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE=y 303 default y 304 305config IMA_QUEUE_EARLY_BOOT_KEYS 306 bool 307 depends on IMA_MEASURE_ASYMMETRIC_KEYS 308 depends on SYSTEM_TRUSTED_KEYRING 309 default y 310 311config IMA_SECURE_AND_OR_TRUSTED_BOOT 312 bool 313 depends on IMA_ARCH_POLICY 314 help 315 This option is selected by architectures to enable secure and/or 316 trusted boot based on IMA runtime policies. 317 318config IMA_DISABLE_HTABLE 319 bool "Disable htable to allow measurement of duplicate records" 320 default n 321 help 322 This option disables htable to allow measurement of duplicate records. 323 324endif 325