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Add two tests that verify md5 and sha1 FP sigantures won't work when --fips-limits is enabled. And upgrade the hashes used from md5 to sha2-256.
267 lines
12 KiB
Python
267 lines
12 KiB
Python
# Copyright (C) 2020-2025 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
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"""
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Run {valgrind} {valgrind_args} {clamscan} --fips-limits tests.
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"""
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import unittest
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import hashlib
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from zipfile import ZIP_DEFLATED, ZipFile
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import sys
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sys.path.append('../unit_tests')
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import testcase
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class TC(testcase.TestCase):
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@classmethod
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def setUpClass(cls):
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super(TC, cls).setUpClass()
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TC.test_file = TC.path_tmp / "test_file"
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with TC.test_file.open('wb') as testfile:
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testfile.write(
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b"""<?php
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IGNORE_user_abort(asdf) scandir(asdfasdfasf]);
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foreach(asdfasfs) strpos(asdfasfsfasf) sdfasdfasdf .php.suspected
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aasdfasdfsf explode asdasdfasfsf
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rename()
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<script>sfasfasf</script>
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?>
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""")
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TC.normalized_match_sig = TC.path_tmp / "normalized.ndb"
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TC.normalized_match_sig.write_text(r"Malicious.PHP.normalized:0:*:69676e6f72655f757365725f61626f7274286173646629")
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TC.original_hash_fp = TC.path_tmp / "original_hash.fp"
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TC.original_hash_fp.write_text(r"845c4893a8a4c666251300718eec7bdbd1b10011b12a08a90a4ab54879f3b9f9:190:original_hash")
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TC.original_hash_wild_fp = TC.path_tmp / "original_hash.wild.fp"
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TC.original_hash_wild_fp.write_text(r"845c4893a8a4c666251300718eec7bdbd1b10011b12a08a90a4ab54879f3b9f9:*:original_hash.wild:73")
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# The normalized hash is this for now. Changes to clamav normalization logic may require
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# changes to this hash.
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TC.normalized_hash_fp = TC.path_tmp / "normalized_hash.fp"
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TC.normalized_hash_fp.write_text(r"93506a60db8ba890558033e77d2e90274013c6c387e1ae11c542bcd65a8b260e:188:normalized_hash")
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TC.normalized_hash_wild_fp = TC.path_tmp / "normalized_hash.wild.fp"
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TC.normalized_hash_wild_fp.write_text(r"93506a60db8ba890558033e77d2e90274013c6c387e1ae11c542bcd65a8b260e:*:normalized_hash.wild:73")
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TC.normalized_md5_fp = TC.path_tmp / "normalized_md5.fp"
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TC.normalized_md5_fp.write_text(r"0e32a3ab501afb50daedc04764f8dc16:188:normalized_hash")
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TC.normalized_sha1_fp = TC.path_tmp / "normalized_sha1.fp"
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TC.normalized_sha1_fp.write_text(r"df6341adaf8c7cec6daaca281b724fad9f9c412e:188:normalized_hash")
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TC.test_file_zipped = TC.path_tmp / 'test_file.zip'
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with ZipFile(str(TC.test_file_zipped), 'w', ZIP_DEFLATED) as zf:
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# Add truncated PNG file that will alert with --alert-broken-media
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with (TC.path_source / 'logo.png').open('br') as logo_png:
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zf.writestr('test_file', b"""<?php
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IGNORE_user_abort(asdf) scandir(asdfasdfasf]);
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foreach(asdfasfs) strpos(asdfasfsfasf) sdfasdfasdf .php.suspected
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aasdfasdfsf explode asdasdfasfsf
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rename()
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<script>sfasfasf</script>
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?>
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""")
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# Generate hash of the zipped file.
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# Since we generated the zip in python, we don't know the hash in advance.
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hash_sha2_256 = hashlib.sha256()
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with TC.test_file_zipped.open("rb") as f:
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for chunk in iter(lambda: f.read(4096), b""):
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hash_sha2_256.update(chunk)
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hash_sha2_256 = hash_sha2_256.hexdigest()
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TC.test_file_zipped_hash_fp = TC.path_tmp / 'test_file.zip.hash.fp'
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TC.test_file_zipped_hash_fp.write_text('{hash}:{size}:test_file.zip'.format(
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hash=hash_sha2_256,
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size=TC.test_file_zipped.stat().st_size))
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TC.test_file_zipped_hash_wild_fp = TC.path_tmp / 'test_file.zip.hash.wild.fp'
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TC.test_file_zipped_hash_wild_fp.write_text('{hash}:*:test_file.zip.wild:73'.format(
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hash=hash_sha2_256))
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@classmethod
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def tearDownClass(cls):
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super(TC, cls).tearDownClass()
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def setUp(self):
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super(TC, self).setUp()
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def tearDown(self):
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super(TC, self).tearDown()
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self.verify_valgrind_log()
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def test_alerts_on_normalized(self):
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"""
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This test expects that the normalized pattern match sig without the .fp sig will in fact alert.
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"""
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self.step_name("Test file detection with pattern from normalized HTML")
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output = self.execute_command(
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"{valgrind} {valgrind_args} {clamscan} --fips-limits {testfiles} -d {db1}".format(
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valgrind=TC.valgrind, valgrind_args=TC.valgrind_args, clamscan=TC.clamscan,
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testfiles=TC.test_file,
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db1=TC.normalized_match_sig,
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)
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)
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self.verify_output(output.out, expected=["Malicious.PHP.normalized.UNOFFICIAL FOUND"], unexpected=[])
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def test_alerts_on_zip(self):
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"""
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This test expects that the OG sig without the .fp sig will in fact alert.
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"""
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self.step_name("Test file detection with pattern from normalized HTML inside a ZIP file")
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output = self.execute_command(
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"{valgrind} {valgrind_args} {clamscan} --fips-limits {testfiles} -d {db1}".format(
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valgrind=TC.valgrind, valgrind_args=TC.valgrind_args, clamscan=TC.clamscan,
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testfiles=TC.test_file_zipped,
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db1=TC.normalized_match_sig,
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)
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)
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self.verify_output(output.out, expected=["Malicious.PHP.normalized.UNOFFICIAL FOUND"], unexpected=[])
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def test_fp_for_normalized(self):
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"""
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This test expects that FP sigs for normalized HTML hashes will work,
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because hashes are now created when an fmap is created and all embedded
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file content to be scanned now gets its own fmap.
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"""
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self.step_name("Test file trusted with fixed-size hash of the normalized HTML")
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output = self.execute_command(
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"{valgrind} {valgrind_args} {clamscan} --fips-limits {testfiles} -d {db1} -d {db2} ".format(
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valgrind=TC.valgrind, valgrind_args=TC.valgrind_args, clamscan=TC.clamscan,
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testfiles=TC.test_file,
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db1=TC.normalized_match_sig,
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db2=TC.normalized_hash_fp,
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)
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)
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self.verify_output(output.out, expected=["OK"], unexpected=[])
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def test_fp_for_normalized_fips_md5(self):
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"""
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This test expects that FP sigs for normalized HTML hashes will fail if using md5 with --fips-limits
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This is because --fips-limits will prevent loading md5 and sha1 FP signatures.
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We can't test with --fips-limits disabled beacuse those tests will fail in a fips-enabled environment where
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these limits are forced.
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"""
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self.step_name("Test file trusted with fixed-size hash of the normalized HTML")
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output = self.execute_command(
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"{valgrind} {valgrind_args} {clamscan} --fips-limits {testfiles} -d {db1} -d {db2} ".format(
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valgrind=TC.valgrind, valgrind_args=TC.valgrind_args, clamscan=TC.clamscan,
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testfiles=TC.test_file,
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db1=TC.normalized_match_sig,
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db2=TC.normalized_md5_fp,
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)
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)
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self.verify_output(output.out, expected=["Malicious.PHP.normalized.UNOFFICIAL FOUND"], unexpected=[])
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def test_fp_for_normalized_fips_sha1(self):
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"""
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This test expects that FP sigs for normalized HTML hashes will fail if using sha1 with --fips-limits
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This is because --fips-limits will prevent loading md5 and sha1 FP signatures.
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We can't test with --fips-limits disabled beacuse those tests will fail in a fips-enabled environment where
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these limits are forced.
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"""
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self.step_name("Test file trusted with fixed-size hash of the normalized HTML")
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output = self.execute_command(
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"{valgrind} {valgrind_args} {clamscan} --fips-limits {testfiles} -d {db1} -d {db2} ".format(
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valgrind=TC.valgrind, valgrind_args=TC.valgrind_args, clamscan=TC.clamscan,
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testfiles=TC.test_file,
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db1=TC.normalized_match_sig,
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db2=TC.normalized_sha1_fp,
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)
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)
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self.verify_output(output.out, expected=["Malicious.PHP.normalized.UNOFFICIAL FOUND"], unexpected=[])
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def test_fp_for_normalized_wild(self):
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"""
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This test expects that wildcard FP sigs for normalized HTML hashes will work,
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because hashes are now created when an fmap is created and all embedded
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file content to be scanned now gets its own fmap.
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"""
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self.step_name("Test file trusted with wild-card hash of the normalized HTML")
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output = self.execute_command(
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"{valgrind} {valgrind_args} {clamscan} --fips-limits {testfiles} -d {db1} -d {db2} ".format(
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valgrind=TC.valgrind, valgrind_args=TC.valgrind_args, clamscan=TC.clamscan,
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testfiles=TC.test_file,
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db1=TC.normalized_match_sig,
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db2=TC.normalized_hash_wild_fp,
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)
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)
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self.verify_output(output.out, expected=["OK"], unexpected=[])
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def test_fp_for_nonnormalized(self):
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"""
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This test expects that FP sigs for non-normalized HTML hashes will work,
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because we now check each hash in the fmap recursion list.
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"""
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self.step_name("Test file trusted with the original non-normalized fixed-size hash")
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output = self.execute_command(
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"{valgrind} {valgrind_args} {clamscan} --fips-limits {testfiles} -d {db1} -d {db2}".format(
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valgrind=TC.valgrind, valgrind_args=TC.valgrind_args, clamscan=TC.clamscan,
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testfiles=TC.test_file,
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db1=TC.normalized_match_sig,
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db2=TC.original_hash_fp,
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)
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)
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self.verify_output(output.out, expected=["OK"], unexpected=[])
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def test_fp_for_nonnormalized_wild(self):
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"""
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This test expects that FP sigs for non-normalized HTML hashes will work,
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because we now check each hash in the fmap recursion list.
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"""
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self.step_name("Test file trusted with the original non-normalized wild-card hash")
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output = self.execute_command(
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"{valgrind} {valgrind_args} {clamscan} --fips-limits {testfiles} -d {db1} -d {db2}".format(
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valgrind=TC.valgrind, valgrind_args=TC.valgrind_args, clamscan=TC.clamscan,
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testfiles=TC.test_file,
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db1=TC.normalized_match_sig,
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db2=TC.original_hash_wild_fp,
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)
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)
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self.verify_output(output.out, expected=["OK"], unexpected=[])
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def test_fp_for_zipped_file(self):
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"""
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This test expects that FP sigs for a zip containing the test file will work.
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"""
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self.step_name("Test file trusted with fixed-size hash of zip containing test file")
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output = self.execute_command(
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"{valgrind} {valgrind_args} {clamscan} --fips-limits {testfiles} -d {db1} -d {db2}".format(
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valgrind=TC.valgrind, valgrind_args=TC.valgrind_args, clamscan=TC.clamscan,
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testfiles=TC.test_file_zipped,
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db1=TC.normalized_match_sig,
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db2=TC.test_file_zipped_hash_fp,
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)
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)
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self.verify_output(output.out, expected=["OK"], unexpected=[])
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def test_fp_for_zipped_file_wild(self):
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"""
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This test expects that FP sigs for a zip containing the test file will work.
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"""
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self.step_name("Test file trusted with wildcard hash of zip containing test file")
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output = self.execute_command(
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"{valgrind} {valgrind_args} {clamscan} --fips-limits {testfiles} -d {db1} -d {db2}".format(
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valgrind=TC.valgrind, valgrind_args=TC.valgrind_args, clamscan=TC.clamscan,
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testfiles=TC.test_file_zipped,
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db1=TC.normalized_match_sig,
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db2=TC.test_file_zipped_hash_wild_fp,
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)
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)
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self.verify_output(output.out, expected=["OK"], unexpected=[])
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