Refactor hashing out into separate library

eos/core/hashing/__init__.py

@@ -0,0 +1,82 @@
+#   Eos - Verifiable elections
+#   Copyright © 2017  RunasSudo (Yingtong Li)
+#
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU Affero General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU Affero General Public License for more details.
+#
+#   You should have received a copy of the GNU Affero General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+try:
+	__pragma__ = __pragma__
+	is_python = False
+except:
+	is_python = True
+	def __pragma__(*args):
+		pass
+
+from eos.core.bigint import *
+
+# Libraries
+# =========
+
+if is_python:
+	__pragma__('skip')
+	import base64
+	import hashlib
+	__pragma__('noskip')
+else:
+	# Load jssha-sha256.js
+	lib = __pragma__('js', '''
+	(function() {{
+		{}
+		var exports = {{}};
+		exports.jsSHA = window.jsSHA;
+		return exports;
+	}})()''', __include__('eos/core/hashing/jssha-sha256.js'))
+
+# Implementation
+# ==============
+
+class SHA256:
+	def __init__(self):
+		if is_python:
+			self.impl = hashlib.sha256()
+		else:
+			# TNYI: This is completely borked
+			self.impl = __pragma__('js', '{}', 'new lib.jsSHA("SHA-256", "TEXT")')
+	
+	def update_text(self, *values):
+		for value in values:
+			if is_python:
+				self.impl.update(value.encode('utf-8'))
+			else:
+				self.impl.js_update(value)
+		return self
+	
+	def update_bigint(self, *values):
+		for value in values:
+			self.update_text(str(value))
+		return self
+	
+	def hash_as_b64(self):
+		if is_python:
+			return base64.b64encode(self.impl.digest()).decode('utf-8')
+		else:
+			return self.impl.getHash('B64')
+	
+	def hash_as_hex(self):
+		if is_python:
+			return self.impl.hexdigest()
+		else:
+			return self.impl.getHash('HEX')
+	
+	def hash_as_bigint(self):
+		return BigInt(self.hash_as_hex(), 16)

eos/core/objects/__init__.py

@@ -36,16 +36,14 @@ if is_python:
 	import uuid
 	__pragma__('noskip')
 else:
-	# Load json.js, jssha-sha256.js
+	# Load json.js
 	lib = __pragma__('js', '''
 	(function() {{
-		{}
 		{}
 		var exports = {{}};
 		exports.stringify = stringify_main;
-		exports.jsSHA = window.jsSHA;
 		return exports;
-	}})()''', __include__('eos/core/objects/json.js'), __include__('eos/core/objects/jssha-sha256.js'))
+	}})()''', __include__('eos/core/objects/json.js'))
 
 # Database
 # ========
@@ -155,7 +153,7 @@ class EosObject(metaclass=EosObjectType):
 	
 	@property
 	def hash(self):
-		return EosObject.to_sha256(EosObject.to_json(EosObject.serialise_and_wrap(self)))[0]
+		return SHA256().update_text(EosObject.to_json(EosObject.serialise_and_wrap(self))).hash_as_b64()
 	
 	@staticmethod
 	def serialise_and_wrap(value, object_type=None):
@@ -184,22 +182,6 @@ class EosObject(metaclass=EosObjectType):
 			return json.loads(value)
 		else:
 			return JSON.parse(value)
-	
-	@staticmethod
-	def to_sha256(*values):
-		from eos.core.bigint import BigInt
-		
-		if is_python:
-			sha_obj = hashlib.sha256()
-			for value in values:
-				sha_obj.update(value.encode('utf-8'))
-			return base64.b64encode(sha_obj.digest()).decode('utf-8'), BigInt(sha_obj.hexdigest(), 16)
-		else:
-			# TNYI: This is completely borked
-			sha_obj = __pragma__('js', '{}', 'new lib.jsSHA("SHA-256", "TEXT")')
-			for value in values:
-				sha_obj.js_update(value)
-			return sha_obj.getHash('B64'), BigInt(sha_obj.getHash('HEX'), 16)
 
 class EosList(EosObject):
 	def __init__(self, *args):

eos/core/tests.py

@@ -16,6 +16,7 @@
 
 from eos.core.bigint import *
 from eos.core.objects import *
+from eos.core.hashing import *
 
 # Common library things
 # ===================
@@ -95,7 +96,7 @@ class ObjectTestCase(EosTestCase):
 
 class HashTestCase(EosTestCase):
 	def test_hash(self):
-		self.assertEqual(EosObject.to_sha256('Hello World!')[0], 'f4OxZX/x/FO5LcGBSKHWXfwtSx+j1ncoSt3SABJtkGk=')
+		self.assertEqual(SHA256().update_text('Hello World!').hash_as_b64(), 'f4OxZX/x/FO5LcGBSKHWXfwtSx+j1ncoSt3SABJtkGk=')
 
 class BigIntTestCase(EosTestCase):
 	def test_basic(self):

eos/js.py

@@ -16,9 +16,13 @@
 
 import eos.core.objects
 import eos.core.bigint
+import eos.core.hashing
 
 import eos.base.election
 import eos.base.workflow
 
 import eos.psr.bitstream
 import eos.psr.crypto
+import eos.psr.election
+import eos.psr.mixnet
+import eos.psr.workflow

eos/psr/crypto.py

@@ -16,6 +16,7 @@
 
 from eos.core.bigint import *
 from eos.core.objects import *
+from eos.core.hashing import *
 from eos.base.election import *
 
 class CyclicGroup(EmbeddedObject):
@@ -120,7 +121,7 @@ class SEGPublicKey(EGPublicKey):
 		gamma = pow(self.group.g, r, self.group.p) # h
 		delta = (message * pow(self.X, r, self.group.p)) % self.group.p # f
 		
-		_, c = EosObject.to_sha256(str(pow(self.group.g, s, self.group.p)), str(gamma), str(delta))
+		c = SHA256().update_bigint(pow(self.group.g, s, self.group.p), gamma, delta).hash_as_bigint()
 		
 		z = s + c*r
 		
@@ -136,6 +137,6 @@ class SEGCiphertext(EGCiphertext):
 	
 	def is_signature_valid(self):
 		gs = (pow(self.public_key.group.g, self.z, self.public_key.group.p) * pow(self.gamma, self.public_key.group.p - ONE - self.c, self.public_key.group.p)) % self.public_key.group.p
-		_, c = EosObject.to_sha256(str(gs), str(self.gamma), str(self.delta))
+		c = SHA256().update_bigint(gs, self.gamma, self.delta).hash_as_bigint()
 		
 		return self.c == c

eos/psr/mixnet.py

@@ -16,6 +16,7 @@
 
 from eos.core.bigint import *
 from eos.core.objects import *
+from eos.core.hashing import *
 from eos.psr.election import *
 
 class RPCMixnet:
@@ -63,7 +64,7 @@ class RPCMixnet:
 			for i in range(len(permutations_and_reenc)):
 				val = permutations_and_reenc[i]
 				val_obj = MixChallengeResponse(index=val[0], reenc=val[1], rand=val[2])
-				commitments.append(EosObject.to_sha256(EosObject.to_json(val_obj.serialise()))[1])
+				commitments.append(SHA256().update_text(EosObject.to_json(val_obj.serialise())).hash_as_bigint())
 		else:
 			for i in range(len(permutations_and_reenc)):
 				# Find the answer that went to 'i'
@@ -71,7 +72,7 @@ class RPCMixnet:
 				val = permutations_and_reenc[idx]
 				
 				val_obj = MixChallengeResponse(index=idx, reenc=val[1], rand=val[3])
-				commitments.append(EosObject.to_sha256(EosObject.to_json(val_obj.serialise()))[1])
+				commitments.append(SHA256().update_text(EosObject.to_json(val_obj.serialise())).hash_as_bigint())
 		
 		self.params = permutations_and_reenc
 		return shuffled_answers, commitments

eos/psr/tests.py

@@ -17,6 +17,7 @@
 from eos.core.tests import *
 
 from eos.core.bigint import *
+from eos.core.hashing import *
 from eos.psr.bitstream import *
 from eos.psr.crypto import *
 from eos.psr.election import *
@@ -158,7 +159,7 @@ class MixnetTestCase(EosTestCase):
 			for i in range(len(pts)):
 				perm, reencs, rand = mixnet.challenge(i)
 				val_obj = MixChallengeResponse(index=perm, reenc=reencs, rand=rand)
-				self.assertEqual(commitments[i], EosObject.to_sha256(EosObject.to_json(val_obj.serialise()))[1])
+				self.assertEqual(commitments[i], SHA256().update_text(EosObject.to_json(val_obj.serialise())).hash_as_bigint())
 				
 				if mixnet.is_left:
 					verify_shuffle(i, perm, reencs)