diff options
| -rw-r--r-- | meta-integrity/recipes-security/ima_policy_hashed/files/ima_policy_hashed | 77 | ||||
| -rw-r--r-- | meta-integrity/recipes-security/ima_policy_hashed/ima-policy-hashed_1.0.bb | 20 |
2 files changed, 97 insertions, 0 deletions
diff --git a/meta-integrity/recipes-security/ima_policy_hashed/files/ima_policy_hashed b/meta-integrity/recipes-security/ima_policy_hashed/files/ima_policy_hashed new file mode 100644 index 0000000..7f89c8d --- /dev/null +++ b/meta-integrity/recipes-security/ima_policy_hashed/files/ima_policy_hashed @@ -0,0 +1,77 @@ +# With this policy, all files on regular partitions are +# appraised. Files with signed IMA hash and normal hash are +# accepted. Signed files cannot be modified while hashed files can be +# (which will also update the hash). However, signed files can +# be deleted, so in practice it is still possible to replace them +# with a modified version. +# +# Without EVM, this is obviously not very secure, so this policy is +# just an example and/or basis for further improvements. For that +# purpose, some comments show what could be added to make the policy +# more secure. +# +# With EVM the situation might be different because access +# to the EVM key can be restricted. +# +# Files which are appraised are also measured. This allows +# debugging whether a file is in policy by looking at +# /sys/kernel/security/ima/ascii_runtime_measurements + +# PROC_SUPER_MAGIC +dont_appraise fsmagic=0x9fa0 +dont_measure fsmagic=0x9fa0 +# SYSFS_MAGIC +dont_appraise fsmagic=0x62656572 +dont_measure fsmagic=0x62656572 +# DEBUGFS_MAGIC +dont_appraise fsmagic=0x64626720 +dont_measure fsmagic=0x64626720 +# TMPFS_MAGIC +dont_appraise fsmagic=0x01021994 +dont_measure fsmagic=0x01021994 +# RAMFS_MAGIC +dont_appraise fsmagic=0x858458f6 +dont_measure fsmagic=0x858458f6 +# DEVPTS_SUPER_MAGIC +dont_appraise fsmagic=0x1cd1 +dont_measure fsmagic=0x1cd1 +# BIFMT +dont_appraise fsmagic=0x42494e4d +dont_measure fsmagic=0x42494e4d +# SECURITYFS_MAGIC +dont_appraise fsmagic=0x73636673 +dont_measure fsmagic=0x73636673 +# SELINUXFS_MAGIC +dont_appraise fsmagic=0xf97cff8c +dont_measure fsmagic=0xf97cff8c +# NSFS_MAGIC (introduced in 3.19, see cd025f7 and e149ed2 in the upstream Linux kernel) +dont_appraise fsmagic=0x6e736673 +dont_measure fsmagic=0x6e736673 +# SMACK_MAGIC +dont_appraise fsmagic=0x43415d53 +dont_measure fsmagic=0x43415d53 +# CGROUP_SUPER_MAGIC +dont_appraise fsmagic=0x27e0eb +dont_measure fsmagic=0x27e0eb +# EFIVARFS_MAGIC +dont_appraise fsmagic=0xde5e81e4 +dont_measure fsmagic=0xde5e81e4 + +# Special partition, no checking done. +# dont_measure fsuuid=a11234... +# dont_appraise fsuuid=a11243... + +# Special immutable group. +# appraise appraise_type=imasig func=FILE_CHECK mask=MAY_READ fgroup=200 + +# All executables must be signed - too strict, we need to +# allow installing executables on the device. +# appraise appraise_type=imasig func=FILE_MMAP mask=MAY_EXEC +# appraise appraise_type=imasig func=BPRM_CHECK mask=MAY_EXEC + +# Default rule. Would be needed also when other rules were added that +# determine what to do in case of reading (mask=MAY_READ or +# mask=MAY_EXEC) because otherwise writing does not update the file +# hash. +appraise +measure diff --git a/meta-integrity/recipes-security/ima_policy_hashed/ima-policy-hashed_1.0.bb b/meta-integrity/recipes-security/ima_policy_hashed/ima-policy-hashed_1.0.bb new file mode 100644 index 0000000..3352daa --- /dev/null +++ b/meta-integrity/recipes-security/ima_policy_hashed/ima-policy-hashed_1.0.bb @@ -0,0 +1,20 @@ +SUMMARY = "IMA sample hash policy" +LICENSE = "MIT" +LIC_FILES_CHKSUM = "file://${COREBASE}/meta/COPYING.MIT;md5=3da9cfbcb788c80a0384361b4de20420" + +# This policy file will get installed as /etc/ima/ima-policy. +# It is located via the normal file search path, so a .bbappend +# to this recipe can just point towards one of its own files. +IMA_POLICY ?= "ima_policy_hashed" + +SRC_URI = " \ + file://${IMA_POLICY} \ +" + +do_install () { + install -d ${D}/${sysconfdir}/ima + install ${WORKDIR}/${IMA_POLICY} ${D}/${sysconfdir}/ima/ima-policy +} + +FILES_${PN} = "${sysconfdir}/ima" +RDEPENDS_${PN} = "ima-evm-utils" |