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_APPRAISE_BUILD_POLICY 161 bool "IMA build time configured policy rules" 162 depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS 163 default n 164 help 165 This option defines an IMA appraisal policy at build time, which 166 is enforced at run time without having to specify a builtin 167 policy name on the boot command line. The build time appraisal 168 policy rules persist after loading a custom policy. 169 170 Depending on the rules configured, this policy may require kernel 171 modules, firmware, the kexec kernel image, and/or the IMA policy 172 to be signed. Unsigned files might prevent the system from 173 booting or applications from working properly. 174 175config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS 176 bool "Appraise firmware signatures" 177 depends on IMA_APPRAISE_BUILD_POLICY 178 default n 179 help 180 This option defines a policy requiring all firmware to be signed, 181 including the regulatory.db. If both this option and 182 CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature 183 verification methods are necessary. 184 185config IMA_APPRAISE_REQUIRE_KEXEC_SIGS 186 bool "Appraise kexec kernel image signatures" 187 depends on IMA_APPRAISE_BUILD_POLICY 188 default n 189 help 190 Enabling this rule will require all kexec'ed kernel images to 191 be signed and verified by a public key on the trusted IMA 192 keyring. 193 194 Kernel image signatures can not be verified by the original 195 kexec_load syscall. Enabling this rule will prevent its 196 usage. 197 198config IMA_APPRAISE_REQUIRE_MODULE_SIGS 199 bool "Appraise kernel modules signatures" 200 depends on IMA_APPRAISE_BUILD_POLICY 201 default n 202 help 203 Enabling this rule will require all kernel modules to be signed 204 and verified by a public key on the trusted IMA keyring. 205 206 Kernel module signatures can only be verified by IMA-appraisal, 207 via the finit_module syscall. Enabling this rule will prevent 208 the usage of the init_module syscall. 209 210config IMA_APPRAISE_REQUIRE_POLICY_SIGS 211 bool "Appraise IMA policy signature" 212 depends on IMA_APPRAISE_BUILD_POLICY 213 default n 214 help 215 Enabling this rule will require the IMA policy to be signed and 216 and verified by a key on the trusted IMA keyring. 217 218config IMA_APPRAISE_BOOTPARAM 219 bool "ima_appraise boot parameter" 220 depends on IMA_APPRAISE 221 default y 222 help 223 This option enables the different "ima_appraise=" modes 224 (eg. fix, log) from the boot command line. 225 226config IMA_TRUSTED_KEYRING 227 bool "Require all keys on the .ima keyring be signed (deprecated)" 228 depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING 229 depends on INTEGRITY_ASYMMETRIC_KEYS 230 select INTEGRITY_TRUSTED_KEYRING 231 default y 232 help 233 This option requires that all keys added to the .ima 234 keyring be signed by a key on the system trusted keyring. 235 236 This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING 237 238config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY 239 bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)" 240 depends on SYSTEM_TRUSTED_KEYRING 241 depends on SECONDARY_TRUSTED_KEYRING 242 depends on INTEGRITY_ASYMMETRIC_KEYS 243 select INTEGRITY_TRUSTED_KEYRING 244 default n 245 help 246 Keys may be added to the IMA or IMA blacklist keyrings, if the 247 key is validly signed by a CA cert in the system built-in or 248 secondary trusted keyrings. 249 250 Intermediate keys between those the kernel has compiled in and the 251 IMA keys to be added may be added to the system secondary keyring, 252 provided they are validly signed by a key already resident in the 253 built-in or secondary trusted keyrings. 254 255config IMA_BLACKLIST_KEYRING 256 bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)" 257 depends on SYSTEM_TRUSTED_KEYRING 258 depends on IMA_TRUSTED_KEYRING 259 default n 260 help 261 This option creates an IMA blacklist keyring, which contains all 262 revoked IMA keys. It is consulted before any other keyring. If 263 the search is successful the requested operation is rejected and 264 an error is returned to the caller. 265 266config IMA_LOAD_X509 267 bool "Load X509 certificate onto the '.ima' trusted keyring" 268 depends on IMA_TRUSTED_KEYRING 269 default n 270 help 271 File signature verification is based on the public keys 272 loaded on the .ima trusted keyring. These public keys are 273 X509 certificates signed by a trusted key on the 274 .system keyring. This option enables X509 certificate 275 loading from the kernel onto the '.ima' trusted keyring. 276 277config IMA_X509_PATH 278 string "IMA X509 certificate path" 279 depends on IMA_LOAD_X509 280 default "/etc/keys/x509_ima.der" 281 help 282 This option defines IMA X509 certificate path. 283 284config IMA_APPRAISE_SIGNED_INIT 285 bool "Require signed user-space initialization" 286 depends on IMA_LOAD_X509 287 default n 288 help 289 This option requires user-space init to be signed. 290