diff options
Diffstat (limited to 'dev-python/cryptography/files/CVE-2018-10903.patch')
| -rw-r--r-- | dev-python/cryptography/files/CVE-2018-10903.patch | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/dev-python/cryptography/files/CVE-2018-10903.patch b/dev-python/cryptography/files/CVE-2018-10903.patch new file mode 100644 index 000000000000..1133405fb93d --- /dev/null +++ b/dev-python/cryptography/files/CVE-2018-10903.patch @@ -0,0 +1,76 @@ +From 688e0f673bfbf43fa898994326c6877f00ab19ef Mon Sep 17 00:00:00 2001 +From: Paul Kehrer <paul.l.kehrer@gmail.com> +Date: Tue, 17 Jul 2018 10:47:57 +0800 +Subject: [PATCH] disallow implicit tag truncation with finalize_with_tag + +--- + docs/hazmat/primitives/symmetric-encryption.rst | 1 + + src/cryptography/hazmat/backends/openssl/ciphers.py | 5 +++++ + src/cryptography/hazmat/primitives/ciphers/modes.py | 1 + + tests/hazmat/primitives/test_aes.py | 16 ++++++++++++++++ + 5 files changed, 28 insertions(+) + +diff --git a/docs/hazmat/primitives/symmetric-encryption.rst b/docs/hazmat/primitives/symmetric-encryption.rst +index 5ebcca754..5b6000902 100644 +--- a/docs/hazmat/primitives/symmetric-encryption.rst ++++ b/docs/hazmat/primitives/symmetric-encryption.rst +@@ -670,6 +670,7 @@ Interfaces + :raises ValueError: This is raised when the data provided isn't + a multiple of the algorithm's block size, if ``min_tag_length`` is + less than 4, or if ``len(tag) < min_tag_length``. ++ ``min_tag_length`` is an argument to the ``GCM`` constructor. + :raises NotImplementedError: This is raised if the version of the + OpenSSL backend used is 1.0.1 or earlier. + +diff --git a/src/cryptography/hazmat/backends/openssl/ciphers.py b/src/cryptography/hazmat/backends/openssl/ciphers.py +index 462ffea25..e0ee06ee2 100644 +--- a/src/cryptography/hazmat/backends/openssl/ciphers.py ++++ b/src/cryptography/hazmat/backends/openssl/ciphers.py +@@ -199,6 +199,11 @@ def finalize_with_tag(self, tag): + "finalize_with_tag requires OpenSSL >= 1.0.2. To use this " + "method please update OpenSSL" + ) ++ if len(tag) < self._mode._min_tag_length: ++ raise ValueError( ++ "Authentication tag must be {0} bytes or longer.".format( ++ self._mode._min_tag_length) ++ ) + res = self._backend._lib.EVP_CIPHER_CTX_ctrl( + self._ctx, self._backend._lib.EVP_CTRL_AEAD_SET_TAG, + len(tag), tag +diff --git a/src/cryptography/hazmat/primitives/ciphers/modes.py b/src/cryptography/hazmat/primitives/ciphers/modes.py +index 598dfaa4a..543015fef 100644 +--- a/src/cryptography/hazmat/primitives/ciphers/modes.py ++++ b/src/cryptography/hazmat/primitives/ciphers/modes.py +@@ -220,6 +220,7 @@ def __init__(self, initialization_vector, tag=None, min_tag_length=16): + min_tag_length) + ) + self._tag = tag ++ self._min_tag_length = min_tag_length + + tag = utils.read_only_property("_tag") + initialization_vector = utils.read_only_property("_initialization_vector") +diff --git a/tests/hazmat/primitives/test_aes.py b/tests/hazmat/primitives/test_aes.py +index d6f83ebc2..4ceccf155 100644 +--- a/tests/hazmat/primitives/test_aes.py ++++ b/tests/hazmat/primitives/test_aes.py +@@ -439,3 +439,19 @@ def test_gcm_tag_decrypt_finalize(self, backend): + decryptor.finalize() + else: + decryptor.finalize_with_tag(tag) ++ ++ @pytest.mark.supported( ++ only_if=lambda backend: ( ++ not backend._lib.CRYPTOGRAPHY_OPENSSL_LESS_THAN_102 or ++ backend._lib.CRYPTOGRAPHY_IS_LIBRESSL ++ ), ++ skip_message="Not supported on OpenSSL 1.0.1", ++ ) ++ def test_gcm_tag_decrypt_finalize_tag_length(self, backend): ++ decryptor = base.Cipher( ++ algorithms.AES(b"0" * 16), ++ modes.GCM(b"0" * 12), ++ backend=backend ++ ).decryptor() ++ with pytest.raises(ValueError): ++ decryptor.finalize_with_tag(b"tagtooshort") |