Merge pull request #505 from alex/system-error

Switch to using our own InternalError, instead of SystemError

5 files changed, 22 insertions, 13 deletions

diff --git a/cryptography/exceptions.py b/cryptography/exceptions.py
index 44363c24..2654b453 100644
--- a/cryptography/exceptions.py
+++ b/cryptography/exceptions.py
@@ -34,3 +34,7 @@ class InvalidTag(Exception):
 
 class InvalidSignature(Exception):
     pass
+
+
+class InternalError(Exception):
+    pass
diff --git a/cryptography/hazmat/backends/commoncrypto/backend.py b/cryptography/hazmat/backends/commoncrypto/backend.py
index 7193f1d8..4e70cab5 100644
--- a/cryptography/hazmat/backends/commoncrypto/backend.py
+++ b/cryptography/hazmat/backends/commoncrypto/backend.py
@@ -16,7 +16,9 @@ from __future__ import absolute_import, division, print_function
 from collections import namedtuple
 
 from cryptography import utils
-from cryptography.exceptions import UnsupportedAlgorithm, InvalidTag
+from cryptography.exceptions import (
+    UnsupportedAlgorithm, InvalidTag, InternalError
+)
 from cryptography.hazmat.backends.interfaces import (
     HashBackend, HMACBackend, CipherBackend
 )
@@ -197,8 +199,9 @@ class Backend(object):
                 "the block length"
             )
         else:
-            raise SystemError(
-                "The backend returned an error. Code: {0}".format(response)
+            raise InternalError(
+                "The backend returned an unknown error, consider filing a bug."
+                " Code: {0}.".format(response)
             )
 
 
diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py
index ee82ba71..b5116be4 100644
--- a/cryptography/hazmat/backends/openssl/backend.py
+++ b/cryptography/hazmat/backends/openssl/backend.py
@@ -16,7 +16,9 @@ from __future__ import absolute_import, division, print_function
 import itertools
 
 from cryptography import utils
-from cryptography.exceptions import UnsupportedAlgorithm, InvalidTag
+from cryptography.exceptions import (
+    UnsupportedAlgorithm, InvalidTag, InternalError
+)
 from cryptography.hazmat.backends.interfaces import (
     CipherBackend, HashBackend, HMACBackend
 )
@@ -154,7 +156,7 @@ class Backend(object):
                         "the block length"
                     )
 
-        raise SystemError(
+        raise InternalError(
             "Unknown error code from OpenSSL, you should probably file a bug."
         )
 
diff --git a/tests/hazmat/backends/test_commoncrypto.py b/tests/hazmat/backends/test_commoncrypto.py
index cfa332d0..7cc0f72f 100644
--- a/tests/hazmat/backends/test_commoncrypto.py
+++ b/tests/hazmat/backends/test_commoncrypto.py
@@ -14,7 +14,7 @@
 import pytest
 
 from cryptography import utils
-from cryptography.exceptions import UnsupportedAlgorithm
+from cryptography.exceptions import UnsupportedAlgorithm, InternalError
 from cryptography.hazmat.bindings.commoncrypto.binding import Binding
 from cryptography.hazmat.primitives import interfaces
 from cryptography.hazmat.primitives.ciphers.algorithms import AES
@@ -49,10 +49,10 @@ class TestCommonCrypto(object):
         with pytest.raises(ValueError):
             backend._check_response(backend._lib.kCCAlignmentError)
 
-        with pytest.raises(SystemError):
+        with pytest.raises(InternalError):
             backend._check_response(backend._lib.kCCMemoryFailure)
 
-        with pytest.raises(SystemError):
+        with pytest.raises(InternalError):
             backend._check_response(backend._lib.kCCDecodeError)
 
     def test_nonexistent_aead_cipher(self):
diff --git a/tests/hazmat/backends/test_openssl.py b/tests/hazmat/backends/test_openssl.py
index 2a329920..f01c3f64 100644
--- a/tests/hazmat/backends/test_openssl.py
+++ b/tests/hazmat/backends/test_openssl.py
@@ -14,7 +14,7 @@
 import pytest
 
 from cryptography import utils
-from cryptography.exceptions import UnsupportedAlgorithm
+from cryptography.exceptions import UnsupportedAlgorithm, InternalError
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.backends.openssl.backend import backend, Backend
 from cryptography.hazmat.primitives import interfaces
@@ -76,20 +76,20 @@ class TestOpenSSL(object):
             cipher.encryptor()
 
     def test_handle_unknown_error(self):
-        with pytest.raises(SystemError):
+        with pytest.raises(InternalError):
             backend._handle_error_code(0, 0, 0)
 
-        with pytest.raises(SystemError):
+        with pytest.raises(InternalError):
             backend._handle_error_code(backend._lib.ERR_LIB_EVP, 0, 0)
 
-        with pytest.raises(SystemError):
+        with pytest.raises(InternalError):
             backend._handle_error_code(
                 backend._lib.ERR_LIB_EVP,
                 backend._lib.EVP_F_EVP_ENCRYPTFINAL_EX,
                 0
             )
 
-        with pytest.raises(SystemError):
+        with pytest.raises(InternalError):
             backend._handle_error_code(
                 backend._lib.ERR_LIB_EVP,
                 backend._lib.EVP_F_EVP_DECRYPTFINAL_EX,