[LTP] [PATCH v2 1/2] IMA: Add a test to verify measurment of keys
Lachlan Sneff
t-josne@linux.microsoft.com
Fri Jun 12 16:38:41 CEST 2020
Add a testcase that verifies that the IMA subsystem has correctly
measured keys added to keyrings specified in the IMA policy file.
Additionally, add support for handling a new IMA template descriptor,
namely ima-buf[1], in the IMA measurement tests.
[1]: https://www.kernel.org/doc/html/latest/security/IMA-templates.html#use
Signed-off-by: Lachlan Sneff <t-josne@linux.microsoft.com>
---
runtest/ima | 1 +
.../integrity/ima/datafiles/keycheck.policy | 1 +
.../security/integrity/ima/tests/ima_keys.sh | 65 +++++++++++++++++++
.../integrity/ima/tests/ima_measurements.sh | 36 +---------
.../integrity/ima/tests/ima_policy.sh | 1 -
.../security/integrity/ima/tests/ima_setup.sh | 35 ++++++++++
6 files changed, 103 insertions(+), 36 deletions(-)
create mode 100644 testcases/kernel/security/integrity/ima/datafiles/keycheck.policy
create mode 100755 testcases/kernel/security/integrity/ima/tests/ima_keys.sh
diff --git a/runtest/ima b/runtest/ima
index f3ea88cf0..309d47420 100644
--- a/runtest/ima
+++ b/runtest/ima
@@ -3,4 +3,5 @@ ima_measurements ima_measurements.sh
ima_policy ima_policy.sh
ima_tpm ima_tpm.sh
ima_violations ima_violations.sh
+ima_keys ima_keys.sh
evm_overlay evm_overlay.sh
diff --git a/testcases/kernel/security/integrity/ima/datafiles/keycheck.policy b/testcases/kernel/security/integrity/ima/datafiles/keycheck.policy
new file mode 100644
index 000000000..3f1934a3d
--- /dev/null
+++ b/testcases/kernel/security/integrity/ima/datafiles/keycheck.policy
@@ -0,0 +1 @@
+measure func=KEY_CHECK keyrings=.ima|.evm|.builtin_trusted_keys|.blacklist template=ima-buf
diff --git a/testcases/kernel/security/integrity/ima/tests/ima_keys.sh b/testcases/kernel/security/integrity/ima/tests/ima_keys.sh
new file mode 100755
index 000000000..f9c60a6fc
--- /dev/null
+++ b/testcases/kernel/security/integrity/ima/tests/ima_keys.sh
@@ -0,0 +1,65 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2020 Microsoft Corporation
+# Author: Lachlan Sneff <t-josne@linux.microsoft.com>
+#
+# Verify that keys are measured correctly based on policy.
+
+TST_NEEDS_CMDS="awk cut xxd"
+TST_CNT=1
+TST_NEEDS_DEVICE=1
+
+. ima_setup.sh
+
+# Based on https://lkml.org/lkml/2019/12/13/564.
+# (450d0fd51564 - "IMA: Call workqueue functions to measure queued keys")
+test1()
+{
+ local keyrings keycheck_line templates test_file="$PWD/test.txt"
+
+ tst_res TINFO "verifying key measurement for keyrings and templates specified in IMA policy file"
+
+ [ -f $IMA_POLICY ] || tst_brk TCONF "missing $IMA_POLICY"
+
+ [ -r $IMA_POLICY ] || tst_brk TCONF "cannot read IMA policy (CONFIG_IMA_READ_POLICY=y required)"
+
+ keycheck_line=$(grep "func=KEY_CHECK" $IMA_POLICY)
+ if [ -z "$keycheck_line" ]; then
+ tst_brk TCONF "ima policy does not specify \"func=KEY_CHECK\""
+ fi
+
+ if echo "$keycheck_line" | grep -q "*keyrings*"; then
+ tst_brk TCONF "ima policy does not specify a keyrings to check"
+ fi
+
+ keyrings=$(echo "$keycheck_line" | tr " " "\n" | grep "keyrings" | \
+ sed "s/\./\\\./g" | cut -d'=' -f2)
+ if [ -z "$keyrings" ]; then
+ tst_brk TCONF "ima policy has a keyring key-value specifier, but no specified keyrings"
+ fi
+
+ templates=$(echo "$keycheck_line" | tr " " "\n" | grep "template" | \
+ cut -d'=' -f2)
+
+ grep -E "($templates)*($keyrings)" $ASCII_MEASUREMENTS | while read line
+ do
+ local digest expected_digest algorithm
+
+ digest=$(echo "$line" | cut -d' ' -f4 | cut -d':' -f2)
+ algorithm=$(echo "$line" | cut -d' ' -f4 | cut -d':' -f1)
+ keyring=$(echo "$line" | cut -d' ' -f5)
+
+ echo "$line" | cut -d' ' -f6 | xxd -r -p > $test_file
+
+ expected_digest="$(compute_digest $algorithm $test_file)" || \
+ tst_brk TCONF "cannot compute digest for $algorithm"
+
+ if [ "$digest" != "$expected_digest" ]; then
+ tst_res TFAIL "incorrect digest was found for the ($keyring) keyring"
+ fi
+ done
+
+ tst_res TPASS "specified keyrings were measured correctly"
+}
+
+tst_run
diff --git a/testcases/kernel/security/integrity/ima/tests/ima_measurements.sh b/testcases/kernel/security/integrity/ima/tests/ima_measurements.sh
index 54237d688..04d8e6353 100755
--- a/testcases/kernel/security/integrity/ima/tests/ima_measurements.sh
+++ b/testcases/kernel/security/integrity/ima/tests/ima_measurements.sh
@@ -28,7 +28,7 @@ setup()
# parse digest index
# https://www.kernel.org/doc/html/latest/security/IMA-templates.html#use
case "$template" in
- ima|ima-ng|ima-sig) DIGEST_INDEX=4 ;;
+ ima|ima-ng|ima-sig|ima-buf) DIGEST_INDEX=4 ;;
*)
# using ima_template_fmt kernel parameter
local IFS="|"
@@ -46,40 +46,6 @@ setup()
"Cannot find digest index (template: '$template')"
}
-# TODO: find support for rmd128 rmd256 rmd320 wp256 wp384 tgr128 tgr160
-compute_digest()
-{
- local algorithm="$1"
- local file="$2"
- local digest
-
- digest="$(${algorithm}sum $file 2>/dev/null | cut -f1 -d ' ')"
- if [ -n "$digest" ]; then
- echo "$digest"
- return 0
- fi
-
- digest="$(openssl $algorithm $file 2>/dev/null | cut -f2 -d ' ')"
- if [ -n "$digest" ]; then
- echo "$digest"
- return 0
- fi
-
- # uncommon ciphers
- local arg="$algorithm"
- case "$algorithm" in
- tgr192) arg="tiger" ;;
- wp512) arg="whirlpool" ;;
- esac
-
- digest="$(rdigest --$arg $file 2>/dev/null | cut -f1 -d ' ')"
- if [ -n "$digest" ]; then
- echo "$digest"
- return 0
- fi
- return 1
-}
-
ima_check()
{
local delimiter=':'
diff --git a/testcases/kernel/security/integrity/ima/tests/ima_policy.sh b/testcases/kernel/security/integrity/ima/tests/ima_policy.sh
index 6286277b4..244cf081d 100755
--- a/testcases/kernel/security/integrity/ima/tests/ima_policy.sh
+++ b/testcases/kernel/security/integrity/ima/tests/ima_policy.sh
@@ -23,7 +23,6 @@ check_policy_writable()
setup()
{
- IMA_POLICY="$IMA_DIR/policy"
check_policy_writable
VALID_POLICY="$TST_DATAROOT/measure.policy"
diff --git a/testcases/kernel/security/integrity/ima/tests/ima_setup.sh b/testcases/kernel/security/integrity/ima/tests/ima_setup.sh
index 58a12eda3..8ae477c1c 100644
--- a/testcases/kernel/security/integrity/ima/tests/ima_setup.sh
+++ b/testcases/kernel/security/integrity/ima/tests/ima_setup.sh
@@ -20,6 +20,40 @@ SYSFS="/sys"
UMOUNT=
TST_FS_TYPE="ext3"
+# TODO: find support for rmd128 rmd256 rmd320 wp256 wp384 tgr128 tgr160
+compute_digest()
+{
+ local algorithm="$1"
+ local file="$2"
+ local digest
+
+ digest="$(${algorithm}sum $file 2>/dev/null | cut -f1 -d ' ')"
+ if [ -n "$digest" ]; then
+ echo "$digest"
+ return 0
+ fi
+
+ digest="$(openssl $algorithm $file 2>/dev/null | cut -f2 -d ' ')"
+ if [ -n "$digest" ]; then
+ echo "$digest"
+ return 0
+ fi
+
+ # uncommon ciphers
+ local arg="$algorithm"
+ case "$algorithm" in
+ tgr192) arg="tiger" ;;
+ wp512) arg="whirlpool" ;;
+ esac
+
+ digest="$(rdigest --$arg $file 2>/dev/null | cut -f1 -d ' ')"
+ if [ -n "$digest" ]; then
+ echo "$digest"
+ return 0
+ fi
+ return 1
+}
+
check_ima_policy()
{
local policy="$1"
@@ -85,6 +119,7 @@ ima_setup()
[ -d "$IMA_DIR" ] || tst_brk TCONF "IMA not enabled in kernel"
ASCII_MEASUREMENTS="$IMA_DIR/ascii_runtime_measurements"
BINARY_MEASUREMENTS="$IMA_DIR/binary_runtime_measurements"
+ IMA_POLICY="$IMA_DIR/policy"
print_ima_config
--
2.25.1
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