From 01998a6b0b1aff11d2d33610cc31ab2034611ff0 Mon Sep 17 00:00:00 2001
From: Sylvain Bellemare <sylvain@ascribe.io>
Date: Wed, 21 Jun 2017 16:04:09 +0200
Subject: [PATCH] Cleaned up rsa module a bit

---
 cryptoconditions/types/rsa.py | 48 +++++++++--------------------------
 1 file changed, 12 insertions(+), 36 deletions(-)

diff --git a/cryptoconditions/types/rsa.py b/cryptoconditions/types/rsa.py
index 19f842e..7c29ebb 100644
--- a/cryptoconditions/types/rsa.py
+++ b/cryptoconditions/types/rsa.py
@@ -7,36 +7,30 @@
 from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives.asymmetric import padding
 from cryptography.hazmat.primitives.asymmetric.rsa import RSAPublicNumbers
-
-#from pyasn1.codec.der.decoder import decode as der_decode
 from pyasn1.codec.der.encoder import encode as der_encode
 from pyasn1.codec.native.decoder import decode as nat_decode
-#from pyasn1.codec.native.encoder import encode as nat_encode
-#
-#from cryptoconditions.condition import Condition
-#from cryptoconditions.fulfillment import Fulfillment
+
 from cryptoconditions.crypto import base64_add_padding
 from cryptoconditions.exceptions import MissingDataError, ValidationError
 from cryptoconditions.types.base_sha256 import BaseSha256
 from cryptoconditions.schemas.fingerprint import RsaFingerprintContents
 
-# Instantiate RSA signer with standard settings
-#rsa = Rsa()
 PUBLIC_EXPONENT = 65537
-#SALT_LENGTH = padding.PSS.MAX_LENGTH
 SALT_LENGTH = 32
 
+
 class RsaSha256(BaseSha256):
     """RSA-SHA-256: RSA signature condition using SHA-256.
 
-    This RSA condition uses RSA-PSS padding with SHA-256. The salt length is set
-    equal the digest length of 32 bytes.
+    This RSA condition uses RSA-PSS padding with SHA-256. The salt
+    length is set equal the digest length of 32 bytes.
 
-    The public exponent is fixed at 65537 and the public modulus must be between
-    128 (1017 bits) and 512 bytes (4096 bits) long.
+    The public exponent is fixed at 65537 and the public modulus must
+    be between 128 (1017 bits) and 512 bytes (4096 bits) long.
 
-    RSA-SHA-256 is assigned the type ID 3. It relies on the SHA-256 and RSA-PSS
-    feature suites which corresponds to a feature bitmask of 0x11.
+    RSA-SHA-256 is assigned the type ID 3. It relies on the SHA-256 and
+    RSA-PSS feature suites which corresponds to a feature bitmask of
+    0x11.
 
     """
     TYPE_ID = 3
@@ -48,11 +42,10 @@ class RsaSha256(BaseSha256):
 
     COST_RIGHT_SHIFT = 6    # 2**6 = 64
 
-    def __init__(self, asn1=None):
+    def __init__(self):
         super().__init__()
         self.modulus = None
         self.signature = None
-        self.asn1 = asn1
 
     def parse_json(self, json):
         self.modulus = urlsafe_b64decode(base64_add_padding(json['modulus']))
@@ -135,11 +128,11 @@ def sign(self, message, private_key):
 
         Args:
             message (bytes): Message to sign.
-            private_key (str):  RSA private key.
+            private_key (bytes):  RSA private key.
 
         """
         private_key_obj = serialization.load_pem_private_key(
-            private_key.encode(),
+            private_key,
             password=None,
             backend=default_backend(),
         )
@@ -158,8 +151,6 @@ def sign(self, message, private_key):
             hashes.SHA256(),
         )
         signer.update(message)
-
-        #self.signature = rsa.sign(private_key, message)
         self.signature = signer.finalize()
 
     def calculate_cost(self):
@@ -208,18 +199,6 @@ def validate(self, message):
             int.from_bytes(self.modulus, byteorder='big'),
         )
         public_key = public_numbers.public_key(default_backend())
-        try:
-            public_key.verify(
-                self.signature,
-                message,
-                padding.PSS(
-                    mgf=padding.MGF1(hashes.SHA256()),
-                    salt_length=SALT_LENGTH,
-                ),
-                hashes.SHA256()
-            )
-        except InvalidSignature as exc:
-            raise ValidationError('Invalid RSA signature') from exc
         verifier = public_key.verifier(
             self.signature,
             padding.PSS(
@@ -234,7 +213,4 @@ def validate(self, message):
         except InvalidSignature as exc:
             raise ValidationError('Invalid RSA signature') from exc
 
-        #pss_result = rsa.verify(self.modulus, message, self.signature)
-        #if not pss_result:
-        #    raise ValidationError('Invalid RSA signature')
         return True