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 <https://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 || SECURITY_APPARMOR) 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 110 111 config IMA_DEFAULT_HASH_SM3 112 bool "SM3" 113 depends on CRYPTO_SM3_GENERIC=y 114endchoice 115 116config IMA_DEFAULT_HASH 117 string 118 default "sha1" if IMA_DEFAULT_HASH_SHA1 119 default "sha256" if IMA_DEFAULT_HASH_SHA256 120 default "sha512" if IMA_DEFAULT_HASH_SHA512 121 default "wp512" if IMA_DEFAULT_HASH_WP512 122 default "sm3" if IMA_DEFAULT_HASH_SM3 123 124config IMA_WRITE_POLICY 125 bool "Enable multiple writes to the IMA policy" 126 default n 127 help 128 IMA policy can now be updated multiple times. The new rules get 129 appended to the original policy. Have in mind that the rules are 130 scanned in FIFO order so be careful when you design and add new ones. 131 132 If unsure, say N. 133 134config IMA_READ_POLICY 135 bool "Enable reading back the current IMA policy" 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 default n 146 help 147 This option enables local measurement integrity appraisal. 148 It requires the system to be labeled with a security extended 149 attribute containing the file hash measurement. To protect 150 the security extended attributes from offline attack, enable 151 and configure EVM. 152 153 For more information on integrity appraisal refer to: 154 <http://linux-ima.sourceforge.net> 155 If unsure, say N. 156 157config IMA_ARCH_POLICY 158 bool "Enable loading an IMA architecture specific policy" 159 depends on (KEXEC_SIG && IMA) || IMA_APPRAISE \ 160 && INTEGRITY_ASYMMETRIC_KEYS 161 default n 162 help 163 This option enables loading an IMA architecture specific policy 164 based on run time secure boot flags. 165 166config IMA_APPRAISE_BUILD_POLICY 167 bool "IMA build time configured policy rules" 168 depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS 169 default n 170 help 171 This option defines an IMA appraisal policy at build time, which 172 is enforced at run time without having to specify a builtin 173 policy name on the boot command line. The build time appraisal 174 policy rules persist after loading a custom policy. 175 176 Depending on the rules configured, this policy may require kernel 177 modules, firmware, the kexec kernel image, and/or the IMA policy 178 to be signed. Unsigned files might prevent the system from 179 booting or applications from working properly. 180 181config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS 182 bool "Appraise firmware signatures" 183 depends on IMA_APPRAISE_BUILD_POLICY 184 default n 185 help 186 This option defines a policy requiring all firmware to be signed, 187 including the regulatory.db. If both this option and 188 CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature 189 verification methods are necessary. 190 191config IMA_APPRAISE_REQUIRE_KEXEC_SIGS 192 bool "Appraise kexec kernel image signatures" 193 depends on IMA_APPRAISE_BUILD_POLICY 194 default n 195 help 196 Enabling this rule will require all kexec'ed kernel images to 197 be signed and verified by a public key on the trusted IMA 198 keyring. 199 200 Kernel image signatures can not be verified by the original 201 kexec_load syscall. Enabling this rule will prevent its 202 usage. 203 204config IMA_APPRAISE_REQUIRE_MODULE_SIGS 205 bool "Appraise kernel modules signatures" 206 depends on IMA_APPRAISE_BUILD_POLICY 207 default n 208 help 209 Enabling this rule will require all kernel modules to be signed 210 and verified by a public key on the trusted IMA keyring. 211 212 Kernel module signatures can only be verified by IMA-appraisal, 213 via the finit_module syscall. Enabling this rule will prevent 214 the usage of the init_module syscall. 215 216config IMA_APPRAISE_REQUIRE_POLICY_SIGS 217 bool "Appraise IMA policy signature" 218 depends on IMA_APPRAISE_BUILD_POLICY 219 default n 220 help 221 Enabling this rule will require the IMA policy to be signed and 222 and verified by a key on the trusted IMA keyring. 223 224config IMA_APPRAISE_BOOTPARAM 225 bool "ima_appraise boot parameter" 226 depends on IMA_APPRAISE 227 default y 228 help 229 This option enables the different "ima_appraise=" modes 230 (eg. fix, log) from the boot command line. 231 232config IMA_APPRAISE_MODSIG 233 bool "Support module-style signatures for appraisal" 234 depends on IMA_APPRAISE 235 depends on INTEGRITY_ASYMMETRIC_KEYS 236 select PKCS7_MESSAGE_PARSER 237 select MODULE_SIG_FORMAT 238 default n 239 help 240 Adds support for signatures appended to files. The format of the 241 appended signature is the same used for signed kernel modules. 242 The modsig keyword can be used in the IMA policy to allow a hook 243 to accept such signatures. 244 245config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY 246 bool "Permit keys validly signed by a built-in, machine (if configured) or secondary" 247 depends on SYSTEM_TRUSTED_KEYRING 248 depends on SECONDARY_TRUSTED_KEYRING 249 depends on INTEGRITY_ASYMMETRIC_KEYS 250 select INTEGRITY_TRUSTED_KEYRING 251 default n 252 help 253 Keys may be added to the IMA or IMA blacklist keyrings, if the 254 key is validly signed by a CA cert in the system built-in, 255 machine (if configured), or secondary trusted keyrings. The 256 key must also have the digitalSignature usage set. 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, machine (if configured) 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 INTEGRITY_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 INTEGRITY_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. 298 299config IMA_MEASURE_ASYMMETRIC_KEYS 300 bool 301 depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE=y 302 default y 303 304config IMA_QUEUE_EARLY_BOOT_KEYS 305 bool 306 depends on IMA_MEASURE_ASYMMETRIC_KEYS 307 depends on SYSTEM_TRUSTED_KEYRING 308 default y 309 310config IMA_SECURE_AND_OR_TRUSTED_BOOT 311 bool 312 depends on IMA_ARCH_POLICY 313 help 314 This option is selected by architectures to enable secure and/or 315 trusted boot based on IMA runtime policies. 316 317config IMA_DISABLE_HTABLE 318 bool "Disable htable to allow measurement of duplicate records" 319 default n 320 help 321 This option disables htable to allow measurement of duplicate records. 322 323endif 324