security/integrity/ima/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 # IBM Integrity Measurement Architecture
   3 #
   4 config IMA
   5         bool "Integrity Measurement Architecture(IMA)"
   6         select SECURITYFS
   7         select CRYPTO
   8         select CRYPTO_HMAC
   9         select CRYPTO_MD5
  10         select CRYPTO_SHA1
  11         select CRYPTO_HASH_INFO
  12         select TCG_TPM if HAS_IOMEM && !UML
  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 <http://www.usenix.org/events/sec04/tech/sailer.html>
  30           to learn more about IMA.
  31           If unsure, say N.
  32
  33 config IMA_KEXEC
  34         bool "Enable carrying the IMA measurement list across a soft boot"
  35         depends on IMA && TCG_TPM && HAVE_IMA_KEXEC
  36         default n
  37         help
  38            TPM PCRs are only reset on a hard reboot.  In order to validate
  39            a TPM's quote after a soft boot, the IMA measurement list of the
  40            running kernel must be saved and restored on boot.
  41
  42            Depending on the IMA policy, the measurement list can grow to
  43            be very large.
  44
  45 config IMA_MEASURE_PCR_IDX
  46         int
  47         depends on IMA
  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
  55 config IMA_LSM_RULES
  56         bool
  57         depends on IMA && AUDIT && (SECURITY_SELINUX || SECURITY_SMACK)
  58         default y
  59         help
  60           Disabling this option will disregard LSM based policy rules.
  61
  62 choice
  63         prompt "Default template"
  64         default IMA_NG_TEMPLATE
  65         depends on IMA
  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.
  74
  75         config IMA_TEMPLATE
  76                 bool "ima"
  77         config IMA_NG_TEMPLATE
  78                 bool "ima-ng (default)"
  79         config IMA_SIG_TEMPLATE
  80                 bool "ima-sig"
  81 endchoice
  82
  83 config IMA_DEFAULT_TEMPLATE
  84         string
  85         depends on IMA
  86         default "ima" if IMA_TEMPLATE
  87         default "ima-ng" if IMA_NG_TEMPLATE
  88         default "ima-sig" if IMA_SIG_TEMPLATE
  89
  90 choice
  91         prompt "Default integrity hash algorithm"
  92         default IMA_DEFAULT_HASH_SHA1
  93         depends on IMA
  94         help
  95            Select the default hash algorithm used for the measurement
  96            list, integrity appraisal and audit log.  The compiled default
  97            hash algorithm can be overwritten using the kernel command
  98            line 'ima_hash=' option.
  99
 100         config IMA_DEFAULT_HASH_SHA1
 101                 bool "SHA1 (default)"
 102                 depends on CRYPTO_SHA1=y
 103
 104         config IMA_DEFAULT_HASH_SHA256
 105                 bool "SHA256"
 106                 depends on CRYPTO_SHA256=y && !IMA_TEMPLATE
 107
 108         config IMA_DEFAULT_HASH_SHA512
 109                 bool "SHA512"
 110                 depends on CRYPTO_SHA512=y && !IMA_TEMPLATE
 111
 112         config IMA_DEFAULT_HASH_WP512
 113                 bool "WP512"
 114                 depends on CRYPTO_WP512=y && !IMA_TEMPLATE
 115 endchoice
 116
 117 config IMA_DEFAULT_HASH
 118         string
 119         depends on IMA
 120         default "sha1" if IMA_DEFAULT_HASH_SHA1
 121         default "sha256" if IMA_DEFAULT_HASH_SHA256
 122         default "sha512" if IMA_DEFAULT_HASH_SHA512
 123         default "wp512" if IMA_DEFAULT_HASH_WP512
 124
 125 config IMA_WRITE_POLICY
 126         bool "Enable multiple writes to the IMA policy"
 127         depends on IMA
 128         default n
 129         help
 130           IMA policy can now be updated multiple times.  The new rules get
 131           appended to the original policy.  Have in mind that the rules are
 132           scanned in FIFO order so be careful when you design and add new ones.
 133
 134           If unsure, say N.
 135
 136 config IMA_READ_POLICY
 137         bool "Enable reading back the current IMA policy"
 138         depends on IMA
 139         default y if IMA_WRITE_POLICY
 140         default n if !IMA_WRITE_POLICY
 141         help
 142            It is often useful to be able to read back the IMA policy.  It is
 143            even more important after introducing CONFIG_IMA_WRITE_POLICY.
 144            This option allows the root user to see the current policy rules.
 145
 146 config IMA_APPRAISE
 147         bool "Appraise integrity measurements"
 148         depends on IMA
 149         default n
 150         help
 151           This option enables local measurement integrity appraisal.
 152           It requires the system to be labeled with a security extended
 153           attribute containing the file hash measurement.  To protect
 154           the security extended attributes from offline attack, enable
 155           and configure EVM.
 156
 157           For more information on integrity appraisal refer to:
 158           <http://linux-ima.sourceforge.net>
 159           If unsure, say N.
 160
 161 config IMA_ARCH_POLICY
 162         bool "Enable loading an IMA architecture specific policy"
 163         depends on (KEXEC_VERIFY_SIG && IMA) || IMA_APPRAISE \
 164                    && INTEGRITY_ASYMMETRIC_KEYS
 165         default n
 166         help
 167           This option enables loading an IMA architecture specific policy
 168           based on run time secure boot flags.
 169
 170 config IMA_APPRAISE_BUILD_POLICY
 171         bool "IMA build time configured policy rules"
 172         depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS
 173         default n
 174         help
 175           This option defines an IMA appraisal policy at build time, which
 176           is enforced at run time without having to specify a builtin
 177           policy name on the boot command line.  The build time appraisal
 178           policy rules persist after loading a custom policy.
 179
 180           Depending on the rules configured, this policy may require kernel
 181           modules, firmware, the kexec kernel image, and/or the IMA policy
 182           to be signed.  Unsigned files might prevent the system from
 183           booting or applications from working properly.
 184
 185 config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS
 186         bool "Appraise firmware signatures"
 187         depends on IMA_APPRAISE_BUILD_POLICY
 188         default n
 189         help
 190           This option defines a policy requiring all firmware to be signed,
 191           including the regulatory.db.  If both this option and
 192           CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature
 193           verification methods are necessary.
 194
 195 config IMA_APPRAISE_REQUIRE_KEXEC_SIGS
 196         bool "Appraise kexec kernel image signatures"
 197         depends on IMA_APPRAISE_BUILD_POLICY
 198         default n
 199         help
 200           Enabling this rule will require all kexec'ed kernel images to
 201           be signed and verified by a public key on the trusted IMA
 202           keyring.
 203
 204           Kernel image signatures can not be verified by the original
 205           kexec_load syscall.  Enabling this rule will prevent its
 206           usage.
 207
 208 config IMA_APPRAISE_REQUIRE_MODULE_SIGS
 209         bool "Appraise kernel modules signatures"
 210         depends on IMA_APPRAISE_BUILD_POLICY
 211         default n
 212         help
 213           Enabling this rule will require all kernel modules to be signed
 214           and verified by a public key on the trusted IMA keyring.
 215
 216           Kernel module signatures can only be verified by IMA-appraisal,
 217           via the finit_module syscall. Enabling this rule will prevent
 218           the usage of the init_module syscall.
 219
 220 config IMA_APPRAISE_REQUIRE_POLICY_SIGS
 221         bool "Appraise IMA policy signature"
 222         depends on IMA_APPRAISE_BUILD_POLICY
 223         default n
 224         help
 225           Enabling this rule will require the IMA policy to be signed and
 226           and verified by a key on the trusted IMA keyring.
 227
 228 config IMA_APPRAISE_BOOTPARAM
 229         bool "ima_appraise boot parameter"
 230         depends on IMA_APPRAISE && !IMA_ARCH_POLICY
 231         default y
 232         help
 233           This option enables the different "ima_appraise=" modes
 234           (eg. fix, log) from the boot command line.
 235
 236 config IMA_TRUSTED_KEYRING
 237         bool "Require all keys on the .ima keyring be signed (deprecated)"
 238         depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
 239         depends on INTEGRITY_ASYMMETRIC_KEYS
 240         select INTEGRITY_TRUSTED_KEYRING
 241         default y
 242         help
 243            This option requires that all keys added to the .ima
 244            keyring be signed by a key on the system trusted keyring.
 245
 246            This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING
 247
 248 config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
 249         bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
 250         depends on SYSTEM_TRUSTED_KEYRING
 251         depends on SECONDARY_TRUSTED_KEYRING
 252         depends on INTEGRITY_ASYMMETRIC_KEYS
 253         select INTEGRITY_TRUSTED_KEYRING
 254         default n
 255         help
 256           Keys may be added to the IMA or IMA blacklist keyrings, if the
 257           key is validly signed by a CA cert in the system built-in or
 258           secondary trusted keyrings.
 259
 260           Intermediate keys between those the kernel has compiled in and the
 261           IMA keys to be added may be added to the system secondary keyring,
 262           provided they are validly signed by a key already resident in the
 263           built-in or secondary trusted keyrings.
 264
 265 config IMA_BLACKLIST_KEYRING
 266         bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)"
 267         depends on SYSTEM_TRUSTED_KEYRING
 268         depends on IMA_TRUSTED_KEYRING
 269         default n
 270         help
 271            This option creates an IMA blacklist keyring, which contains all
 272            revoked IMA keys.  It is consulted before any other keyring.  If
 273            the search is successful the requested operation is rejected and
 274            an error is returned to the caller.
 275
 276 config IMA_LOAD_X509
 277         bool "Load X509 certificate onto the '.ima' trusted keyring"
 278         depends on IMA_TRUSTED_KEYRING
 279         default n
 280         help
 281            File signature verification is based on the public keys
 282            loaded on the .ima trusted keyring. These public keys are
 283            X509 certificates signed by a trusted key on the
 284            .system keyring.  This option enables X509 certificate
 285            loading from the kernel onto the '.ima' trusted keyring.
 286
 287 config IMA_X509_PATH
 288         string "IMA X509 certificate path"
 289         depends on IMA_LOAD_X509
 290         default "/etc/keys/x509_ima.der"
 291         help
 292            This option defines IMA X509 certificate path.
 293
 294 config IMA_APPRAISE_SIGNED_INIT
 295         bool "Require signed user-space initialization"
 296         depends on IMA_LOAD_X509
 297         default n
 298         help
 299            This option requires user-space init to be signed.