Shamira Changeset - 735b9c2a61e9

Changeset - 735b9c2a61e9

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Laman - 7 years ago 2017-10-01 17:51:06

cli catching thrown exceptions

4 files changed with 21 insertions and 9 deletions:

src/cli.py

src/condensed.py

src/shamira.py

src/tests/test_shamira.py

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src/cli.py

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@@ @@ -3,25 +3,25 @@ @@
 from argparse import ArgumentParser
 from shamira import generate, reconstruct
 def run():
 	parser=ArgumentParser()
 	subparsers=parser.add_subparsers()
 	buildSplitParser(subparsers.add_parser("split"))
 	buildJoinParser(subparsers.add_parser("join"))
 	parser.set_defaults(func=lambda: parser.error("missing command"))
+	parser.set_defaults(func=lambda _: parser.error("missing command"))
 	args=parser.parse_args()
 	args.func(args)
 def buildSplitParser(parser):
 	parser.add_argument("-k",type=int,required=True,help="number of shares necessary for recovering the secret")
 	parser.add_argument("-n",type=int,required=True,help="number of generated shares")
 	encoding=parser.add_mutually_exclusive_group()
 	encoding.add_argument("--hex",action="store_true",help="encode shares' bytes as a hexadecimal string")
 	encoding.add_argument("--b32",action="store_true",help="encode shares' bytes as a base32 string")
@@ @@ -36,27 +36,33 @@ def buildJoinParser(parser): @@
 	encoding.add_argument("--hex",action="store_true",help="decode shares' bytes from a hexadecimal string")
 	encoding.add_argument("--b32",action="store_true",help="decode shares' bytes from a base32 string")
 	encoding.add_argument("--b64",action="store_true",help="decode shares' bytes from a base64 string")
 	parser.add_argument("-r","--raw",action="store_true",help="return secret as raw bytes")
 	parser.add_argument("share",nargs="+",help="shares to be joined")
 	parser.set_defaults(func=_reconstruct)
 def _generate(args):
 	encoding=getEncoding(args) or "b32"
 	shares=generate(args.secret,args.k,args.n,encoding)
 	for s in shares:
 		print(s)
 	try:
 		shares=generate(args.secret,args.k,args.n,encoding)
 		for s in shares:
 			print(s)
 	except ValueError as e:
 		print("operation failed: ",e)
 def _reconstruct(args):
 	encoding=getEncoding(args)
 	print(reconstruct(*args.share,encoding=encoding,raw=args.raw))
 	try:
 		print(reconstruct(*args.share,encoding=encoding,raw=args.raw))
 	except ValueError as e:
 		print("operation failed: ",e)
 def getEncoding(args):
 	if args.hex: return "hex"
 	elif args.b32: return "b32"
 	elif args.b64: return "b64"
 	else: return ""

src/condensed.py

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@@ @@ -90,22 +90,27 @@ def decode(share): @@
 ###
 from argparse import ArgumentParser
 def run():
 	parser=ArgumentParser()
 	subparsers=parser.add_subparsers()
 	joiner=subparsers.add_parser("join")
 	joiner.add_argument("share",nargs="+",help="shares to be joined")
-	joiner.set_defaults(func=lambda args: print(reconstruct(*args.share)))
+	joiner.set_defaults(func=_reconstruct)
 	parser.set_defaults(func=lambda: parser.error("missing command"))
 	args=parser.parse_args()
 	args.func(args)
 def _reconstruct(args):
 	try: print(reconstruct(*args.share))
 	except ValueError as e: print("operation failed: ",e)
 if __name__=="__main__":
 	run()

src/shamira.py

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 # GNU GPLv3, see LICENSE
 import os
 import re
 import base64
 import binascii
 import gf256
 def _shareByte(secretB,k,n):
 	assert k<=n<255
 	if not k<=n<255:
 		raise ValueError("failing k<=n<255, k={0}, n={1}".format(k,n))
 	coefs=[int(secretB)]+[int(b) for b in os.urandom(k-1)]
 	points=[gf256.evaluate(coefs,i) for i in range(1,n+1)]
 	return points
 def generateRaw(secret,k,n):
 	"""Splits secret into shares.
 	:param secret: (bytes)
 	:param k: number of shares necessary for secret recovery. 1 <= k <= n
 	:param n: (int) number of shares generated. 1 <= n < 255
 	:return: [(i, (bytes) share), ...]"""

src/tests/test_shamira.py

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@@ @@ -11,27 +11,27 @@ class TestShamira(TestCase): @@
 	_urandom=os.urandom
 	@classmethod
 	def setUpClass(cls):
 		random.seed(17)
 		os.urandom=lambda n: bytes(random.randint(0,255) for i in range(n))
 	@classmethod
 	def tearDownClass(cls):
 		os.urandom=cls._urandom
 	def test_shareByte(self):
-		with self.assertRaises(AssertionError): # too few shares
+		with self.assertRaises(ValueError): # too few shares
 			_shareByte(b"a",5,4)
-		with self.assertRaises(AssertionError): # too many shares
+		with self.assertRaises(ValueError): # too many shares
 			_shareByte(b"a",5,255)
 		with self.assertRaises(ValueError): # not castable to int
 			_shareByte("x",2,3)
 		vals=_shareByte(ord(b"a"),2,3)
 		points=list(zip(range(1,256), vals))
 		self.assertEqual(gf256.getConstantCoef(*points), ord(b"a"))
 		self.assertEqual(gf256.getConstantCoef(*points[:2]), ord(b"a"))
 		self.assertNotEqual(gf256.getConstantCoef(*points[:1]), ord(b"a")) # underdetermined => random
 	def testGenerateReconstructRaw(self):
 		for (k,n) in [(2,3), (254,254)]:

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