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. 298