security/integrity/ima/Kconfig

   1 # IBM Integrity Measurement Architecture
   2 #
   3 config 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_IBMVTPM if TCG_TPM && PPC_PSERIES
  14         help
  15           The Trusted Computing Group(TCG) runtime Integrity
  16           Measurement Architecture(IMA) maintains a list of hash
  17           values of executables and other sensitive system files,
  18           as they are read or executed. If an attacker manages
  19           to change the contents of an important system file
  20           being measured, we can tell.
  21
  22           If your system has a TPM chip, then IMA also maintains
  23           an aggregate integrity value over this list inside the
  24           TPM hardware, so that the TPM can prove to a third party
  25           whether or not critical system files have been modified.
  26           Read <http://www.usenix.org/events/sec04/tech/sailer.html>
  27           to learn more about IMA.
  28           If unsure, say N.
  29
  30 config IMA_KEXEC
  31         bool "Enable carrying the IMA measurement list across a soft boot"
  32         depends on IMA && TCG_TPM && HAVE_IMA_KEXEC
  33         default n
  34         help
  35            TPM PCRs are only reset on a hard reboot.  In order to validate
  36            a TPM's quote after a soft boot, the IMA measurement list of the
  37            running kernel must be saved and restored on boot.
  38
  39            Depending on the IMA policy, the measurement list can grow to
  40            be very large.
  41
  42 config IMA_MEASURE_PCR_IDX
  43         int
  44         depends on IMA
  45         range 8 14
  46         default 10
  47         help
  48           IMA_MEASURE_PCR_IDX determines the TPM PCR register index
  49           that IMA uses to maintain the integrity aggregate of the
  50           measurement list.  If unsure, use the default 10.
  51
  52 config IMA_LSM_RULES
  53         bool
  54         depends on IMA && AUDIT && (SECURITY_SELINUX || SECURITY_SMACK)
  55         default y
  56         help
  57           Disabling this option will disregard LSM based policy rules.
  58
  59 choice
  60         prompt "Default template"
  61         default IMA_NG_TEMPLATE
  62         depends on IMA
  63         help
  64           Select the default IMA measurement template.
  65
  66           The original 'ima' measurement list template contains a
  67           hash, defined as 20 bytes, and a null terminated pathname,
  68           limited to 255 characters.  The 'ima-ng' measurement list
  69           template permits both larger hash digests and longer
  70           pathnames.
  71
  72         config IMA_TEMPLATE
  73                 bool "ima"
  74         config IMA_NG_TEMPLATE
  75                 bool "ima-ng (default)"
  76         config IMA_SIG_TEMPLATE
  77                 bool "ima-sig"
  78 endchoice
  79
  80 config IMA_DEFAULT_TEMPLATE
  81         string
  82         depends on IMA
  83         default "ima" if IMA_TEMPLATE
  84         default "ima-ng" if IMA_NG_TEMPLATE
  85         default "ima-sig" if IMA_SIG_TEMPLATE
  86
  87 choice
  88         prompt "Default integrity hash algorithm"
  89         default IMA_DEFAULT_HASH_SHA1
  90         depends on IMA
  91         help
  92            Select the default hash algorithm used for the measurement
  93            list, integrity appraisal and audit log.  The compiled default
  94            hash algorithm can be overwritten using the kernel command
  95            line 'ima_hash=' option.
  96
  97         config IMA_DEFAULT_HASH_SHA1
  98                 bool "SHA1 (default)"
  99                 depends on CRYPTO_SHA1=y
 100
 101         config IMA_DEFAULT_HASH_SHA256
 102                 bool "SHA256"
 103                 depends on CRYPTO_SHA256=y && !IMA_TEMPLATE
 104
 105         config IMA_DEFAULT_HASH_SHA512
 106                 bool "SHA512"
 107                 depends on CRYPTO_SHA512=y && !IMA_TEMPLATE
 108
 109         config IMA_DEFAULT_HASH_WP512
 110                 bool "WP512"
 111                 depends on CRYPTO_WP512=y && !IMA_TEMPLATE
 112 endchoice
 113
 114 config IMA_DEFAULT_HASH
 115         string
 116         depends on IMA
 117         default "sha1" if IMA_DEFAULT_HASH_SHA1
 118         default "sha256" if IMA_DEFAULT_HASH_SHA256
 119         default "sha512" if IMA_DEFAULT_HASH_SHA512
 120         default "wp512" if IMA_DEFAULT_HASH_WP512
 121
 122 config IMA_WRITE_POLICY
 123         bool "Enable multiple writes to the IMA policy"
 124         depends on IMA
 125         default n
 126         help
 127           IMA policy can now be updated multiple times.  The new rules get
 128           appended to the original policy.  Have in mind that the rules are
 129           scanned in FIFO order so be careful when you design and add new ones.
 130
 131           If unsure, say N.
 132
 133 config IMA_READ_POLICY
 134         bool "Enable reading back the current IMA policy"
 135         depends on IMA
 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
 143 config IMA_APPRAISE
 144         bool "Appraise integrity measurements"
 145         depends on IMA
 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
 158 config IMA_APPRAISE_BOOTPARAM
 159         bool "ima_appraise boot parameter"
 160         depends on IMA_APPRAISE
 161         default y
 162         help
 163           This option enables the different "ima_appraise=" modes
 164           (eg. fix, log) from the boot command line.
 165
 166 config IMA_TRUSTED_KEYRING
 167         bool "Require all keys on the .ima keyring be signed (deprecated)"
 168         depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
 169         depends on INTEGRITY_ASYMMETRIC_KEYS
 170         select INTEGRITY_TRUSTED_KEYRING
 171         default y
 172         help
 173            This option requires that all keys added to the .ima
 174            keyring be signed by a key on the system trusted keyring.
 175
 176            This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING
 177
 178 config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
 179         bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
 180         depends on SYSTEM_TRUSTED_KEYRING
 181         depends on SECONDARY_TRUSTED_KEYRING
 182         depends on INTEGRITY_ASYMMETRIC_KEYS
 183         select INTEGRITY_TRUSTED_KEYRING
 184         default n
 185         help
 186           Keys may be added to the IMA or IMA blacklist keyrings, if the
 187           key is validly signed by a CA cert in the system built-in or
 188           secondary trusted keyrings.
 189
 190           Intermediate keys between those the kernel has compiled in and the
 191           IMA keys to be added may be added to the system secondary keyring,
 192           provided they are validly signed by a key already resident in the
 193           built-in or secondary trusted keyrings.
 194
 195 config IMA_BLACKLIST_KEYRING
 196         bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)"
 197         depends on SYSTEM_TRUSTED_KEYRING
 198         depends on IMA_TRUSTED_KEYRING
 199         default n
 200         help
 201            This option creates an IMA blacklist keyring, which contains all
 202            revoked IMA keys.  It is consulted before any other keyring.  If
 203            the search is successful the requested operation is rejected and
 204            an error is returned to the caller.
 205
 206 config IMA_LOAD_X509
 207         bool "Load X509 certificate onto the '.ima' trusted keyring"
 208         depends on IMA_TRUSTED_KEYRING
 209         default n
 210         help
 211            File signature verification is based on the public keys
 212            loaded on the .ima trusted keyring. These public keys are
 213            X509 certificates signed by a trusted key on the
 214            .system keyring.  This option enables X509 certificate
 215            loading from the kernel onto the '.ima' trusted keyring.
 216
 217 config IMA_X509_PATH
 218         string "IMA X509 certificate path"
 219         depends on IMA_LOAD_X509
 220         default "/etc/keys/x509_ima.der"
 221         help
 222            This option defines IMA X509 certificate path.
 223
 224 config IMA_APPRAISE_SIGNED_INIT
 225         bool "Require signed user-space initialization"
 226         depends on IMA_LOAD_X509
 227         default n
 228         help
 229            This option requires user-space init to be signed.