81 lines
2.8 KiB
Diff
81 lines
2.8 KiB
Diff
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From add9847988e963fd124863736592fc16cc8c716b Mon Sep 17 00:00:00 2001
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From: Stefan Berger <stefanb@linux.ibm.com>
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Date: Tue, 11 Jul 2023 18:03:28 -0400
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Subject: [PATCH 14/14] tpm_util: Replace a logger.error with an Exception in
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case of invalid signature
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This fixes a possibly severe issue in 7.2.5 & 7.3.0.
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Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
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---
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keylime/tpm/tpm_util.py | 6 +-----
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keylime/tpm/tpm_util_test.py | 21 +++++++++++++++++++++
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2 files changed, 22 insertions(+), 5 deletions(-)
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diff --git a/keylime/tpm/tpm_util.py b/keylime/tpm/tpm_util.py
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index ce2ce0f..58a1a04 100644
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--- a/keylime/tpm/tpm_util.py
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+++ b/keylime/tpm/tpm_util.py
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@@ -3,7 +3,6 @@ import string
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import struct
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from typing import Any, Dict, List, Optional, Tuple, Union
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-from cryptography.exceptions import InvalidSignature
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from cryptography.hazmat import backends
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from cryptography.hazmat.primitives import hashes, hmac, serialization
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from cryptography.hazmat.primitives.asymmetric import ec, padding
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@@ -155,10 +154,7 @@ def checkquote(
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digest.update(quoteblob)
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quote_digest = digest.finalize()
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- try:
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- verify(pubkey, signature, quote_digest, hashfunc)
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- except InvalidSignature:
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- logger.error("Invalid quote signature!")
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+ verify(pubkey, signature, quote_digest, hashfunc)
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# Check that reported nonce is expected one
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retDict = tpm2_objects.unmarshal_tpms_attest(quoteblob)
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diff --git a/keylime/tpm/tpm_util_test.py b/keylime/tpm/tpm_util_test.py
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index aaf16cd..2c73997 100644
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--- a/keylime/tpm/tpm_util_test.py
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+++ b/keylime/tpm/tpm_util_test.py
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@@ -2,6 +2,7 @@ import base64
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import unittest
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from unittest import mock
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+from cryptography.exceptions import InvalidSignature
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from cryptography.hazmat.primitives.asymmetric.ec import (
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SECP256R1,
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EllipticCurve,
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@@ -60,6 +61,26 @@ class TestTpmUtil(unittest.TestCase):
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except Exception as e:
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self.fail(f"checkquote failed with {e}")
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+ # test bad input
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+ bad_quoteblob = bytearray(quoteblob)
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+ bad_quoteblob[5] ^= 0x1
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+ with self.assertRaises(InvalidSignature):
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+ checkquote(aikblob, nonce, sigblob, bad_quoteblob, pcrblob, "sha256")
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+
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+ l = list(nonce)
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+ l[0] = "a"
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+ bad_nonce = "".join(l)
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+ with self.assertRaises(Exception):
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+ checkquote(aikblob, bad_nonce, sigblob, quoteblob, pcrblob, "sha256")
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+
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+ bad_pcrblob = bytearray(pcrblob)
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+ bad_pcrblob[5] ^= 0x1
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+ with self.assertRaises(Exception):
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+ checkquote(aikblob, nonce, sigblob, quoteblob, bad_pcrblob, "sha256")
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+
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+ with self.assertRaises(ValueError):
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+ checkquote(aikblob, nonce, sigblob, quoteblob, pcrblob, "sha1")
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+
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@staticmethod
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def not_random(numbytes: int) -> bytes:
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return b"\x12" * numbytes
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--
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2.41.0
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