Merge pull request #129 from mpdavis/backend-explicit-tests

Merge in backend-explicit-tests

.gitignore

@@ -55,3 +55,12 @@ docs/_build/
 
 # PyBuilder
 target/
+
+# PyCharm
+.idea/
+
+# PyEnv
+.python-version
+
+# PyTest
+.pytest_cache/

.travis.yml

@@ -2,21 +2,114 @@
 # detail: https://blog.travis-ci.com/2017-06-21-trusty-updates-2017-Q2-launch
 dist: precise
 language: python
-python:
-  - "2.7"
-  - "3.4"
-  - "3.5"
-  - "3.6"
-  - "pypy-5.3.1"
 install:
   - pip install -U setuptools && pip install -U tox codecov tox-travis
 script:
   - tox
 after_success:
   - codecov
-# matrix:
-#   include:
-#     - python: 3.6
-#       env:
-#         - TOX_ENV=flake8
-#       script: tox -e $TOX_ENV
+matrix:
+  include:
+    # CPython 2.7
+    - python: 2.7
+      env: TOXENV=py27-base
+    - python: 2.7
+      env: TOXENV=py27-cryptography-only
+    - python: 2.7
+      env: TOXENV=py27-pycryptodome-norsa
+    - python: 2.7
+      env: TOXENV=py27-pycrypto-norsa
+    - python: 2.7
+      env: TOXENV=py27-compatibility
+    # CPython 3.4
+    - python: 3.4
+      env: TOXENV=py34-base
+    - python: 3.4
+      env: TOXENV=py34-cryptography-only
+    - python: 3.4
+      env: TOXENV=py34-pycryptodome-norsa
+    - python: 3.4
+      env: TOXENV=py34-pycrypto-norsa
+    - python: 3.4
+      env: TOXENV=py34-compatibility
+    # CPython 3.5
+    - python: 3.5
+      env: TOXENV=py35-base
+    - python: 3.5
+      env: TOXENV=py35-cryptography-only
+    - python: 3.5
+      env: TOXENV=py35-pycryptodome-norsa
+    - python: 3.5
+      env: TOXENV=py35-pycrypto-norsa
+    - python: 3.5
+      env: TOXENV=py35-compatibility
+    # CPython 3.5
+    - python: 3.5
+      env: TOXENV=py35-base
+    - python: 3.5
+      env: TOXENV=py35-cryptography-only
+    - python: 3.5
+      env: TOXENV=py35-pycryptodome-norsa
+    - python: 3.5
+      env: TOXENV=py35-pycrypto-norsa
+    - python: 3.5
+      env: TOXENV=py35-compatibility
+    # CPython 3.6
+    - python: 3.6
+      env: TOXENV=py35-base
+    - python: 3.6
+      env: TOXENV=py35-cryptography-only
+    - python: 3.6
+      env: TOXENV=py35-pycryptodome-norsa
+    - python: 3.6
+      env: TOXENV=py35-pycrypto-norsa
+    - python: 3.6
+      env: TOXENV=py35-compatibility
+    # CPython 3.7
+    # xenial + sudo are currently needed to get 3.7
+    # https://github.com/travis-ci/travis-ci/issues/9815
+    - python: 3.7
+      env: TOXENV=py35-base
+      dist: xenial
+      sudo: true
+    - python: 3.7
+      env: TOXENV=py35-cryptography-only
+      dist: xenial
+      sudo: true
+    - python: 3.7
+      env: TOXENV=py35-pycryptodome-norsa
+      dist: xenial
+      sudo: true
+    - python: 3.7
+      env: TOXENV=py35-pycrypto-norsa
+      dist: xenial
+      sudo: true
+    - python: 3.7
+      env: TOXENV=py35-compatibility
+      dist: xenial
+      sudo: true
+    # PyPy 5.3.1
+    - python: pypy-5.3.1
+      env: TOXENV=pypy-base
+    - python: pypy-5.3.1
+      env: TOXENV=pypy-cryptography-only
+    - python: pypy-5.3.1
+      env: TOXENV=pypy-pycryptodome-norsa
+    - python: pypy-5.3.1
+      env: TOXENV=pypy-pycrypto-norsa
+    - python: pypy-5.3.1
+      env: TOXENV=pypy-compatibility
+    # PyPy 3.5 (5.10.1?)
+    - python: pypy3.5
+      env: TOXENV=pypy-base
+    - python: pypy3.5
+      env: TOXENV=pypy-cryptography-only
+    - python: pypy3.5
+      env: TOXENV=pypy-pycryptodome-norsa
+    - python: pypy3.5
+      env: TOXENV=pypy-pycrypto-norsa
+    - python: pypy3.5
+      env: TOXENV=pypy-compatibility
+    # Linting
+    - python: 3.6
+      env: TOX_ENV=flake8

README.rst

@@ -42,6 +42,23 @@ The crytography option is a good default.
     $ pip install python-jose[pycryptodome]
     $ pip install python-jose[pycrypto]
 
+Due to complexities with setuptools, the ``python-rsa`` and ``python-ecdsa`` libraries are always installed.
+If you use one of the custom backends and would like to clean up unneeded dependencies,
+you can remove the following dependencies for each backend:
+
+* ``cryptography``
+
+  * ``pip uninstall rsa ecdsa pyasn1``
+
+* ``pycrypto`` or ``pycryptodome``
+
+  * ``pip uninstall rsa``
+
+.. warning::
+
+    Uninstall carefully. Make sure that nothing else in your environment needs these
+    libraries before uninstalling them.
+
 
 Usage
 -----

jose/backends/__init__.py

@@ -1,9 +1,9 @@
 
 try:
-    from jose.backends.pycrypto_backend import RSAKey  # noqa: F401
+    from jose.backends.cryptography_backend import CryptographyRSAKey as RSAKey  # noqa: F401
 except ImportError:
     try:
-        from jose.backends.cryptography_backend import CryptographyRSAKey as RSAKey  # noqa: F401
+        from jose.backends.pycrypto_backend import RSAKey  # noqa: F401
     except ImportError:
         from jose.backends.rsa_backend import RSAKey  # noqa: F401
 

jose/backends/_asn1.py

@@ -0,0 +1,82 @@
+"""ASN1 encoding helpers for converting between PKCS1 and PKCS8.
+
+Required by rsa_backend and pycrypto_backend but not cryptography_backend.
+"""
+from pyasn1.codec.der import decoder, encoder
+from pyasn1.type import namedtype, univ
+
+RSA_ENCRYPTION_ASN1_OID = "1.2.840.113549.1.1.1"
+
+
+class RsaAlgorithmIdentifier(univ.Sequence):
+    """ASN1 structure for recording RSA PrivateKeyAlgorithm identifiers."""
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType("rsaEncryption", univ.ObjectIdentifier()),
+        namedtype.NamedType("parameters", univ.Null())
+    )
+
+
+class PKCS8PrivateKey(univ.Sequence):
+    """ASN1 structure for recording PKCS8 private keys."""
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType("version", univ.Integer()),
+        namedtype.NamedType("privateKeyAlgorithm", RsaAlgorithmIdentifier()),
+        namedtype.NamedType("privateKey", univ.OctetString())
+    )
+
+
+class PublicKeyInfo(univ.Sequence):
+    """ASN1 structure for recording PKCS8 public keys."""
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType("algorithm", RsaAlgorithmIdentifier()),
+        namedtype.NamedType("publicKey", univ.BitString())
+    )
+
+
+def rsa_private_key_pkcs8_to_pkcs1(pkcs8_key):
+    """Convert a PKCS8-encoded RSA private key to PKCS1."""
+    decoded_values = decoder.decode(pkcs8_key, asn1Spec=PKCS8PrivateKey())
+
+    try:
+        decoded_key = decoded_values[0]
+    except IndexError:
+        raise ValueError("Invalid private key encoding")
+
+    return decoded_key["privateKey"]
+
+
+def rsa_private_key_pkcs1_to_pkcs8(pkcs1_key):
+    """Convert a PKCS1-encoded RSA private key to PKCS8."""
+    algorithm = RsaAlgorithmIdentifier()
+    algorithm["rsaEncryption"] = RSA_ENCRYPTION_ASN1_OID
+
+    pkcs8_key = PKCS8PrivateKey()
+    pkcs8_key["version"] = 0
+    pkcs8_key["privateKeyAlgorithm"] = algorithm
+    pkcs8_key["privateKey"] = pkcs1_key
+
+    return encoder.encode(pkcs8_key)
+
+
+def rsa_public_key_pkcs1_to_pkcs8(pkcs1_key):
+    """Convert a PKCS1-encoded RSA private key to PKCS8."""
+    algorithm = RsaAlgorithmIdentifier()
+    algorithm["rsaEncryption"] = RSA_ENCRYPTION_ASN1_OID
+
+    pkcs8_key = PublicKeyInfo()
+    pkcs8_key["algorithm"] = algorithm
+    pkcs8_key["publicKey"] = univ.BitString.fromOctetString(pkcs1_key)
+
+    return encoder.encode(pkcs8_key)
+
+
+def rsa_public_key_pkcs8_to_pkcs1(pkcs8_key):
+    """Convert a PKCS8-encoded RSA private key to PKCS1."""
+    decoded_values = decoder.decode(pkcs8_key, asn1Spec=PublicKeyInfo())
+
+    try:
+        decoded_key = decoded_values[0]
+    except IndexError:
+        raise ValueError("Invalid public key encoding.")
+
+    return decoded_key["publicKey"].asOctets()

jose/backends/cryptography_backend.py

@@ -1,6 +1,13 @@
+from __future__ import division
+
+import math
+
 import six
-import ecdsa
-from ecdsa.util import sigdecode_string, sigencode_string, sigdecode_der, sigencode_der
+
+try:
+    from ecdsa import SigningKey as EcdsaSigningKey, VerifyingKey as EcdsaVerifyingKey
+except ImportError:
+    EcdsaSigningKey = EcdsaVerifyingKey = None
 
 from jose.backends.base import Key
 from jose.utils import base64_to_long, long_to_base64
@@ -11,7 +18,9 @@
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives import hashes, serialization
 from cryptography.hazmat.primitives.asymmetric import ec, rsa, padding
+from cryptography.hazmat.primitives.asymmetric.utils import decode_dss_signature, encode_dss_signature
 from cryptography.hazmat.primitives.serialization import load_pem_private_key, load_pem_public_key
+from cryptography.utils import int_from_bytes, int_to_bytes
 from cryptography.x509 import load_pem_x509_certificate
 
 
@@ -37,7 +46,7 @@ def __init__(self, key, algorithm, cryptography_backend=default_backend):
             self.prepared_key = key
             return
 
-        if isinstance(key, (ecdsa.SigningKey, ecdsa.VerifyingKey)):
+        if None not in (EcdsaSigningKey, EcdsaVerifyingKey) and isinstance(key, (EcdsaSigningKey, EcdsaVerifyingKey)):
             # convert to PEM and let cryptography below load it as PEM
             key = key.to_pem().decode('utf-8')
 
@@ -90,19 +99,42 @@ def _process_jwk(self, jwk_dict):
         else:
             return public.public_key(self.cryptography_backend())
 
+    def _sig_component_length(self):
+        """Determine the correct serialization length for an encoded signature component.
+
+        This is the number of bytes required to encode the maximum key value.
+        """
+        return int(math.ceil(self.prepared_key.key_size / 8.0))
+
+    def _der_to_raw(self, der_signature):
+        """Convert signature from DER encoding to RAW encoding."""
+        r, s = decode_dss_signature(der_signature)
+        component_length = self._sig_component_length()
+        return int_to_bytes(r, component_length) + int_to_bytes(s, component_length)
+
+    def _raw_to_der(self, raw_signature):
+        """Convert signature from RAW encoding to DER encoding."""
+        component_length = self._sig_component_length()
+        if len(raw_signature) != int(2 * component_length):
+            raise ValueError("Invalid signature")
+
+        r_bytes = raw_signature[:component_length]
+        s_bytes = raw_signature[component_length:]
+        r = int_from_bytes(r_bytes, "big")
+        s = int_from_bytes(s_bytes, "big")
+        return encode_dss_signature(r, s)
+
     def sign(self, msg):
         if self.hash_alg.digest_size * 8 > self.prepared_key.curve.key_size:
             raise TypeError("this curve (%s) is too short "
                             "for your digest (%d)" % (self.prepared_key.curve.name,
                                                       8 * self.hash_alg.digest_size))
         signature = self.prepared_key.sign(msg, ec.ECDSA(self.hash_alg()))
-        order = (2 ** self.prepared_key.curve.key_size) - 1
-        return sigencode_string(*sigdecode_der(signature, order), order=order)
+        return self._der_to_raw(signature)
 
     def verify(self, msg, sig):
-        order = (2 ** self.prepared_key.curve.key_size) - 1
-        signature = sigencode_der(*sigdecode_string(sig, order), order=order)
         try:
+            signature = self._raw_to_der(sig)
             self.prepared_key.verify(signature, msg, ec.ECDSA(self.hash_alg()))
             return True
         except Exception: