Changeset - 37a1df17b9a1
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Laman - 4 years ago 2020-04-10 12:49:31

changed naming to snake case. sadly no love for camel case in this world
7 files changed with 98 insertions and 98 deletions:
src/cli.py
9
9
src/condensed.py
11
11
src/gf256.py
6
6
src/shamira.py
18
18
src/tests/test_condensed.py
18
18
src/tests/test_gf256.py
13
13
src/tests/test_shamira.py
23
23
0 comments (0 inline, 0 general)
src/cli.py
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@@ -9,8 +9,8 @@ def run():
 
	parser = ArgumentParser()
 
	subparsers = parser.add_subparsers()
 

			




	
	
	
		
 
	buildSplitParser(subparsers.add_parser("split"))

			




	
	
	
		
 
	buildJoinParser(subparsers.add_parser("join"))

			




	
	
	
		
 
	build_split_parser(subparsers.add_parser("split"))

			




	
	
	
		
 
	build_join_parser(subparsers.add_parser("join"))

			




	
	
	
		
 

			




	
	
	
		
 
	parser.set_defaults(func=lambda _: parser.error("missing command"))

			




	
	
	
		
 

			




	
	
		
 
@@ -18,11 +18,11 @@ def run():

			




	
	
	
		
 
	args.func(args)

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def buildSplitParser(parser):

			




	
	
	
		
 
def build_split_parser(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 = 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")

			




	
	
	
		
 
	encoding.add_argument("--b64", action="store_true", help="encode shares' bytes as a base64 string")

			




	
	
		
 
@@ -31,8 +31,8 @@ def buildSplitParser(parser):

			




	
	
	
		
 
	parser.set_defaults(func=_generate)

			




	
	
	
		
 
	

			




	
	
	
		
 

			




	
	
	
		
 
def buildJoinParser(parser):

			




	
	
	
		
 
	encoding=parser.add_mutually_exclusive_group()

			




	
	
	
		
 
def build_join_parser(parser):

			




	
	
	
		
 
	encoding = parser.add_mutually_exclusive_group()

			




	
	
	
		
 
	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")

			




	
	
		
 
@@ -43,7 +43,7 @@ def buildJoinParser(parser):

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def _generate(args):

			




	
	
	
		
 
	encoding = getEncoding(args) or "b32"

			




	
	
	
		
 
	encoding = get_encoding(args) or "b32"

			




	
	
	
		
 

			




	
	
	
		
 
	try:

			




	
	
	
		
 
		shares = generate(args.secret, args.k, args.n, encoding)

			




	
	
		
 
@@ -54,14 +54,14 @@ def _generate(args):

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def _reconstruct(args):

			




	
	
	
		
 
	encoding = getEncoding(args)

			




	
	
	
		
 
	encoding = get_encoding(args)

			




	
	
	
		
 
	try:

			




	
	
	
		
 
		print(reconstruct(*args.share, encoding=encoding, raw=args.raw))

			




	
	
	
		
 
	except SException as e:

			




	
	
	
		
 
		print(e)

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def getEncoding(args):

			




	
	
	
		
 
def get_encoding(args):

			




	
	
	
		
 
	if args.hex: return "hex"

			




	
	
	
		
 
	elif args.b32: return "b32"

			




	
	
	
		
 
	elif args.b64: return "b64"

			




        

    


    
    

    

        

                

                    src/condensed.py
                

                

                  
                      
                        

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@@ -30,7 +30,7 @@ L[1] = 0

			




	
	
	
		
 
inv = [E[255-L[i]] if i!=0 else None for i in range(256)]  # multiplicative inverse

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def getConstantCoef(*points):

			




	
	
	
		
 
def get_constant_coef(*points):

			




	
	
	
		
 
	"""Compute constant polynomial coefficient given the points.

			




	
	
	
		
 

			




	
	
	
		
 
	See https://en.wikipedia.org/wiki/Shamir's_Secret_Sharing#Computationally_Efficient_Approach"""

			




	
	
		
 
@@ -55,26 +55,26 @@ import binascii

			




	
	
	
		
 
class SException(Exception): pass

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def reconstructRaw(*shares):

			




	
	
	
		
 
def reconstruct_raw(*shares):

			




	
	
	
		
 
	"""Tries to recover the secret from its shares.

			




	
	
	
		
 

			




	
	
	
		
 
	:param shares: ((i, (bytes) share), ...)

			




	
	
	
		
 
	:return: (bytes) reconstructed secret. Too few shares returns garbage."""

			




	
	
	
		
 
	secretLen = len(shares[0][1])

			




	
	
	
		
 
	res = [None]*secretLen

			




	
	
	
		
 
	for i in range(secretLen):

			




	
	
	
		
 
	secret_len = len(shares[0][1])

			




	
	
	
		
 
	res = [None]*secret_len

			




	
	
	
		
 
	for i in range(secret_len):

			




	
	
	
		
 
		points = [(x, s[i]) for (x, s) in shares]

			




	
	
	
		
 
		res[i] = (getConstantCoef(*points))

			




	
	
	
		
 
		res[i] = (get_constant_coef(*points))

			




	
	
	
		
 
	return bytes(res)

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def reconstruct(*shares):

			




	
	
	
		
 
	"""Wraps reconstructRaw.

			




	
	
	
		
 
	"""Wraps reconstruct_raw.

			




	
	
	
		
 

			




	
	
	
		
 
	:param shares: ((str) share, ...)

			




	
	
	
		
 
	:return: (str) reconstructed secret. Too few shares returns garbage."""

			




	
	
	
		
 

			




	
	
	
		
 
	bs = reconstructRaw(*(decode(s) for s in shares))

			




	
	
	
		
 
	bs = reconstruct_raw(*(decode(s) for s in shares))

			




	
	
	
		
 
	try:

			




	
	
	
		
 
		return bs.decode(encoding="utf-8")

			




	
	
	
		
 
	except UnicodeDecodeError:

			




	
	
		
 
@@ -83,13 +83,13 @@ def reconstruct(*shares):

			




	
	
	
		
 

			




	
	
	
		
 
def decode(share):

			




	
	
	
		
 
	try:

			




	
	
	
		
 
		(i, _, shareStr) = share.partition(".")

			




	
	
	
		
 
		(i, _, share_str) = share.partition(".")

			




	
	
	
		
 
		i = int(i)

			




	
	
	
		
 
		if not 1<=i<=255:

			




	
	
	
		
 
			raise SException("Malformed share: Failed 1<=k<=255, k={0}".format(i))

			




	
	
	
		
 

			




	
	
	
		
 
		shareBytes = base64.b32decode(shareStr)

			




	
	
	
		
 
		return (i, shareBytes)

			




	
	
	
		
 
		share_bytes = base64.b32decode(share_str)

			




	
	
	
		
 
		return (i, share_bytes)

			




	
	
	
		
 
	except (ValueError, binascii.Error):

			




	
	
	
		
 
		raise SException('Malformed share: share="{0}"'.format(share))

			




	
	
	
		
 

			




        

    


    
    

    

        

                

                    src/gf256.py
                

                

                  
                      
                        

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@@ -23,7 +23,7 @@ for i in range(256):

			




	
	
	
		
 
	L[acc] = i

			




	
	
	
		
 
	acc = _gfmul(acc, g)

			




	
	
	
		
 
L[1] = 0

			




	
	
	
		
 
inv = [E[255-L[i]] if i != 0 else None for i in range(256)]  # multiplicative inverse

			




	
	
	
		
 
INV = [E[255-L[i]] if i!=0 else None for i in range(256)]  # multiplicative inverse

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def gfmul(a, b):

			




	
	
		
 
@@ -40,14 +40,14 @@ def evaluate(coefs, x):

			




	
	
	
		
 

			




	
	
	
		
 
	:param coefs: [a0, a1, ...]."""

			




	
	
	
		
 
	res = 0

			




	
	
	
		
 
	xK = 1

			




	
	
	
		
 
	xk = 1

			




	
	
	
		
 
	for a in coefs:

			




	
	
	
		
 
		res ^= gfmul(a, xK)

			




	
	
	
		
 
		xK = gfmul(xK, x)

			




	
	
	
		
 
		res ^= gfmul(a, xk)

			




	
	
	
		
 
		xk = gfmul(xk, x)

			




	
	
	
		
 
	return res

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def getConstantCoef(*points):

			




	
	
	
		
 
def get_constant_coef(*points):

			




	
	
	
		
 
	"""Compute constant polynomial coefficient given the points.

			




	
	
	
		
 

			




	
	
	
		
 
	See https://en.wikipedia.org/wiki/Shamir's_Secret_Sharing#Computationally_Efficient_Approach"""

			




	
	
		
 
@@ -59,6 +59,6 @@ def getConstantCoef(*points):

			




	
	
	
		
 
		for j in range(k):

			




	
	
	
		
 
			if i==j: continue

			




	
	
	
		
 
			(xj, yj) = points[j]

			




	
	
	
		
 
			prod = gfmul(prod, (gfmul(xj, inv[xj^x])))

			




	
	
	
		
 
			prod = gfmul(prod, (gfmul(xj, INV[xj^x])))

			




	
	
	
		
 
		res ^= gfmul(y, prod)

			




	
	
	
		
 
	return res

			




        

    


    
    

    

        

                

                    src/shamira.py
                

                

                  
                      
                        

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@@ -15,41 +15,41 @@ class DecodingException(SException): pas

			




	
	
	
		
 
class MalformedShare(SException): pass

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def _shareByte(secretB, k, n):

			




	
	
	
		
 
def _share_byte(secret_b, k, n):

			




	
	
	
		
 
	if not k<=n<255:

			




	
	
	
		
 
		raise InvalidParams("Failed k<=n<255, k={0}, n={1}".format(k, n))

			




	
	
	
		
 
	# we might be concerned with zero coefficients degenerating our polynomial, but there's no reason - we still need k shares to determine it is the case

			




	
	
	
		
 
	coefs = [int(secretB)]+[int(b) for b in os.urandom(k-1)]

			




	
	
	
		
 
	coefs = [int(secret_b)]+[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):

			




	
	
	
		
 
def generate_raw(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), ...]"""

			




	
	
	
		
 
	shares = [_shareByte(b, k, n) for b in secret]

			




	
	
	
		
 
	shares = [_share_byte(b, k, n) for b in secret]

			




	
	
	
		
 
	return [(i+1, bytes([s[i] for s in shares])) for i in range(n)]

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def reconstructRaw(*shares):

			




	
	
	
		
 
def reconstruct_raw(*shares):

			




	
	
	
		
 
	"""Tries to recover the secret from its shares.

			




	
	
	
		
 

			




	
	
	
		
 
	:param shares: ((i, (bytes) share), ...)

			




	
	
	
		
 
	:return: (bytes) reconstructed secret. Too few shares returns garbage."""

			




	
	
	
		
 
	secretLen = len(shares[0][1])

			




	
	
	
		
 
	res = [None]*secretLen

			




	
	
	
		
 
	for i in range(secretLen):

			




	
	
	
		
 
	secret_len = len(shares[0][1])

			




	
	
	
		
 
	res = [None]*secret_len

			




	
	
	
		
 
	for i in range(secret_len):

			




	
	
	
		
 
		points = [(x, s[i]) for (x, s) in shares]

			




	
	
	
		
 
		res[i] = (gf256.getConstantCoef(*points))

			




	
	
	
		
 
		res[i] = (gf256.get_constant_coef(*points))

			




	
	
	
		
 
	return bytes(res)

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def generate(secret, k, n, encoding="b32"):

			




	
	
	
		
 
	"""Wraps generateRaw().

			




	
	
	
		
 
	"""Wraps generate_raw().

			




	
	
	
		
 

			




	
	
	
		
 
	:param secret: (str or bytes)

			




	
	
	
		
 
	:param k: number of shares necessary for secret recovery

			




	
	
		
 
@@ -58,21 +58,21 @@ def generate(secret, k, n, encoding="b32

			




	
	
	
		
 
	:return: [(str) share, ...]"""

			




	
	
	
		
 
	if isinstance(secret,str):

			




	
	
	
		
 
		secret = secret.encode("utf-8")

			




	
	
	
		
 
	shares = generateRaw(secret, k, n)

			




	
	
	
		
 
	shares = generate_raw(secret, k, n)

			




	
	
	
		
 
	return [encode(s, encoding) for s in shares]

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def reconstruct(*shares, encoding="", raw=False):

			




	
	
	
		
 
	"""Wraps reconstructRaw.

			




	
	
	
		
 
	"""Wraps reconstruct_raw.

			




	
	
	
		
 

			




	
	
	
		
 
	:param shares: ((str) share, ...)

			




	
	
	
		
 
	:param encoding: {hex, b32, b64, ""} encoding of share strings. If not provided or empty, the function tries to guess it.

			




	
	
	
		
 
	:param raw: (bool) whether to return bytes (True) or str (False)

			




	
	
	
		
 
	:return: (str or bytes) reconstructed secret. Too few shares returns garbage."""

			




	
	
	
		
 
	if not encoding:

			




	
	
	
		
 
		encoding = detectEncoding(shares)

			




	
	
	
		
 
		encoding = detect_encoding(shares)

			




	
	
	
		
 

			




	
	
	
		
 
	bs = reconstructRaw(*(decode(s, encoding) for s in shares))

			




	
	
	
		
 
	bs = reconstruct_raw(*(decode(s, encoding) for s in shares))

			




	
	
	
		
 
	try:

			




	
	
	
		
 
		return bs if raw else bs.decode(encoding="utf-8")

			




	
	
	
		
 
	except UnicodeDecodeError:

			




	
	
		
 
@@ -89,20 +89,20 @@ def encode(share, encoding="b32"):

			




	
	
	
		
 

			




	
	
	
		
 
def decode(share, encoding="b32"):

			




	
	
	
		
 
	try:

			




	
	
	
		
 
		(i, _, shareStr) = share.partition(".")

			




	
	
	
		
 
		(i, _, share_str) = share.partition(".")

			




	
	
	
		
 
		i = int(i)

			




	
	
	
		
 
		if not 1<=i<=255:

			




	
	
	
		
 
			raise MalformedShare("Malformed share: Failed 1<=k<=255, k={0}".format(i))

			




	
	
	
		
 
		if encoding=="hex": f = base64.b16decode

			




	
	
	
		
 
		elif encoding=="b32": f = base64.b32decode

			




	
	
	
		
 
		else: f = base64.b64decode

			




	
	
	
		
 
		shareBytes = f(shareStr)

			




	
	
	
		
 
		return (i, shareBytes)

			




	
	
	
		
 
		share_bytes = f(share_str)

			




	
	
	
		
 
		return (i, share_bytes)

			




	
	
	
		
 
	except (ValueError, binascii.Error):

			




	
	
	
		
 
		raise MalformedShare('Malformed share: share="{0}", encoding="{1}"'.format(share, encoding))

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
def detectEncoding(shares):

			




	
	
	
		
 
def detect_encoding(shares):

			




	
	
	
		
 
	classes = [

			




	
	
	
		
 
		(re.compile(r"\d+\.([0-9A-F]{2})+"), "hex"),

			




	
	
	
		
 
		(re.compile(r"\d+\.([A-Z2-7]{8})*([A-Z2-7]{8}|[A-Z2-7]{2}={6}|[A-Z2-7]{4}={4}|[A-Z2-7]{5}={3}|[A-Z2-7]{7}={1})"), "b32"),

			




        

    


    
    

    

        

                

                    src/tests/test_condensed.py
                

                

                  
                      
                        

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@@ -5,7 +5,7 @@ import random

			




	
	
	
		
 
from unittest import TestCase

			




	
	
	
		
 

			




	
	
	
		
 
from gf256 import _gfmul, evaluate

			




	
	
	
		
 
from shamira import generateRaw, generate

			




	
	
	
		
 
from shamira import generate_raw, generate

			




	
	
	
		
 
from condensed import *

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
		
 
@@ -21,47 +21,47 @@ class TestCondensed(TestCase):

			




	
	
	
		
 
	def tearDownClass(cls):

			




	
	
	
		
 
		os.urandom = cls._urandom

			




	
	
	
		
 

			




	
	
	
		
 
	def testGfmul(self):

			




	
	
	
		
 
	def test_gfmul(self):

			




	
	
	
		
 
		for a in range(256):

			




	
	
	
		
 
			for b in range(256):

			




	
	
	
		
 
				self.assertEqual(_gfmul(a, b), gfmul(a, b))

			




	
	
	
		
 

			




	
	
	
		
 
	def testGetConstantCoef(self):

			




	
	
	
		
 
		self.assertEqual(getConstantCoef((1, 1), (2, 2), (3, 3)), 0)

			




	
	
	
		
 
	def test_get_constant_coef(self):

			




	
	
	
		
 
		self.assertEqual(get_constant_coef((1, 1), (2, 2), (3, 3)), 0)

			




	
	
	
		
 

			




	
	
	
		
 
		random.seed(17)

			




	
	
	
		
 
		randomMatches = 0

			




	
	
	
		
 
		random_matches = 0

			




	
	
	
		
 
		for i in range(10):

			




	
	
	
		
 
			k = random.randint(2, 255)

			




	
	
	
		
 

			




	
	
	
		
 
			# exact

			




	
	
	
		
 
			res = self.checkCoefsMatch(k, k)

			




	
	
	
		
 
			res = self.check_coefs_match(k, k)

			




	
	
	
		
 
			self.assertEqual(res[0], res[1])

			




	
	
	
		
 

			




	
	
	
		
 
			# overdetermined

			




	
	
	
		
 
			res = self.checkCoefsMatch(k, 256)

			




	
	
	
		
 
			res = self.check_coefs_match(k, 256)

			




	
	
	
		
 
			self.assertEqual(res[0], res[1])

			




	
	
	
		
 

			




	
	
	
		
 
			# underdetermined => random

			




	
	
	
		
 
			res = self.checkCoefsMatch(k, k-1)

			




	
	
	
		
 
			res = self.check_coefs_match(k, k-1)

			




	
	
	
		
 
			if res[0]==res[1]:

			




	
	
	
		
 
				randomMatches += 1

			




	
	
	
		
 
		self.assertLess(randomMatches, 2)  # with a chance (255/256)**10=0.96 there should be no match

			




	
	
	
		
 
				random_matches += 1

			




	
	
	
		
 
		self.assertLess(random_matches, 2)  # with a chance (255/256)**10=0.96 there should be no match

			




	
	
	
		
 

			




	
	
	
		
 
	def checkCoefsMatch(self, k, m):

			




	
	
	
		
 
	def check_coefs_match(self, k, m):

			




	
	
	
		
 
		coefs = [random.randint(0, 255) for i in range(k)]

			




	
	
	
		
 
		points = [(j, evaluate(coefs, j)) for j in range(1, 256)]

			




	
	
	
		
 
		random.shuffle(points)

			




	
	
	
		
 
		return (getConstantCoef(*points[:m]), coefs[0])

			




	
	
	
		
 
		return (get_constant_coef(*points[:m]), coefs[0])

			




	
	
	
		
 

			




	
	
	
		
 
	def testGenerateReconstructRaw(self):

			




	
	
	
		
 
	def test_generate_reconstruct_raw(self):

			




	
	
	
		
 
		for (k, n) in [(2, 3), (254, 254)]:

			




	
	
	
		
 
			shares = generateRaw(b"abcd", k, n)

			




	
	
	
		
 
			shares = generate_raw(b"abcd", k, n)

			




	
	
	
		
 
			random.shuffle(shares)

			




	
	
	
		
 
			self.assertEqual(reconstructRaw(*shares[:k]), b"abcd")

			




	
	
	
		
 
			self.assertNotEqual(reconstructRaw(*shares[:k-1]), b"abcd")

			




	
	
	
		
 
			self.assertEqual(reconstruct_raw(*shares[:k]), b"abcd")

			




	
	
	
		
 
			self.assertNotEqual(reconstruct_raw(*shares[:k-1]), b"abcd")

			




	
	
	
		
 

			




	
	
	
		
 
	def testGenerateReconstruct(self):

			




	
	
	
		
 
	def test_generate_reconstruct(self):

			




	
	
	
		
 
		for secret in ["abcde", "ěščřžý"]:

			




	
	
	
		
 
			for (k, n) in [(2, 3), (254, 254)]:

			




	
	
	
		
 
				with self.subTest(sec=secret, k=k, n=n):

			




	
	
		
 
@@ -76,7 +76,7 @@ class TestCondensed(TestCase):

			




	
	
	
		
 
		with self.assertRaises(SException):

			




	
	
	
		
 
			reconstruct(*shares)

			




	
	
	
		
 

			




	
	
	
		
 
	def testDecode(self):

			




	
	
	
		
 
	def test_decode(self):

			




	
	
	
		
 
		with self.assertRaises(SException):

			




	
	
	
		
 
			decode("AAA")

			




	
	
	
		
 
			decode("1.")

			




        

    


    
    

    

        

                

                    src/tests/test_gf256.py
                

                

                  
                      
                        

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@@ -9,7 +9,7 @@ from gf256 import *

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
class TestGF256(TestCase):

			




	
	
	
		
 
	def test_gfmul(self):

			




	
	
	
		
 
	def test__gfmul(self):

			




	
	
	
		
 
		self.assertEqual(_gfmul(0, 0), 0)

			




	
	
	
		
 
		self.assertEqual(_gfmul(1, 1), 1)

			




	
	
	
		
 
		self.assertEqual(_gfmul(2, 2), 4)

			




	
	
		
 
@@ -17,45 +17,45 @@ class TestGF256(TestCase):

			




	
	
	
		
 
		self.assertEqual(_gfmul(0x53, 0xca), 0x01)

			




	
	
	
		
 
		self.assertEqual(_gfmul(0xff, 0xff), 0x13)

			




	
	
	
		
 

			




	
	
	
		
 
	def testGfmul(self):

			




	
	
	
		
 
	def test_gfmul(self):

			




	
	
	
		
 
		for a in range(256):

			




	
	
	
		
 
			for b in range(256):

			




	
	
	
		
 
				self.assertEqual(_gfmul(a, b), gfmul(a, b))

			




	
	
	
		
 

			




	
	
	
		
 
	def testEvaluate(self):

			




	
	
	
		
 
	def test_evaluate(self):

			




	
	
	
		
 
		for x in range(256):

			




	
	
	
		
 
			(a0, a1, a2, a3) = (x, x>>1, x>>2, x>>3)

			




	
	
	
		
 
			self.assertEqual(evaluate([17], x), 17)  # constant polynomial

			




	
	
	
		
 
			self.assertEqual(evaluate([a0, a1, a2, a3], 0), x)  # any polynomial at 0

			




	
	
	
		
 
			self.assertEqual(evaluate([a0, a1, a2, a3], 1), a0^a1^a2^a3)  # polynomial at 1 == sum of coefficients

			




	
	
	
		
 

			




	
	
	
		
 
	def testGetConstantCoef(self):

			




	
	
	
		
 
		self.assertEqual(getConstantCoef((1, 1), (2, 2), (3, 3)), 0)

			




	
	
	
		
 
	def test_get_constant_coef(self):

			




	
	
	
		
 
		self.assertEqual(get_constant_coef((1, 1), (2, 2), (3, 3)), 0)

			




	
	
	
		
 

			




	
	
	
		
 
		random.seed(17)

			




	
	
	
		
 
		randomMatches = 0

			




	
	
	
		
 
		random_matches = 0

			




	
	
	
		
 
		for i in range(10):

			




	
	
	
		
 
			k = random.randint(2, 255)

			




	
	
	
		
 

			




	
	
	
		
 
			# exact

			




	
	
	
		
 
			res = self.checkCoefsMatch(k, k)

			




	
	
	
		
 
			res = self.check_coefs_match(k, k)

			




	
	
	
		
 
			self.assertEqual(res[0], res[1])

			




	
	
	
		
 

			




	
	
	
		
 
			# overdetermined

			




	
	
	
		
 
			res = self.checkCoefsMatch(k, 256)

			




	
	
	
		
 
			res = self.check_coefs_match(k, 256)

			




	
	
	
		
 
			self.assertEqual(res[0], res[1])

			




	
	
	
		
 

			




	
	
	
		
 
			# underdetermined => random

			




	
	
	
		
 
			res = self.checkCoefsMatch(k, k-1)

			




	
	
	
		
 
			res = self.check_coefs_match(k, k-1)

			




	
	
	
		
 
			if res[0]==res[1]:

			




	
	
	
		
 
				randomMatches += 1

			




	
	
	
		
 
		self.assertLess(randomMatches, 2)  # with a chance (255/256)**10=0.96 there should be no match

			




	
	
	
		
 
				random_matches += 1

			




	
	
	
		
 
		self.assertLess(random_matches, 2)  # with a chance (255/256)**10=0.96 there should be no match

			




	
	
	
		
 

			




	
	
	
		
 
	def checkCoefsMatch(self, k, m):

			




	
	
	
		
 
	def check_coefs_match(self, k, m):

			




	
	
	
		
 
		coefs = [random.randint(0, 255) for i in range(k)]

			




	
	
	
		
 
		points = [(j, evaluate(coefs, j)) for j in range(1, 256)]

			




	
	
	
		
 
		random.shuffle(points)

			




	
	
	
		
 
		return (getConstantCoef(*points[:m]), coefs[0])

			




	
	
	
		
 
		return (get_constant_coef(*points[:m]), coefs[0])

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
	
		
 
if __name__=='__main__':

			




        

    


    
    

    

        

                

                    src/tests/test_shamira.py
                

                

                  
                      
                        

                      ➞

                      
                        
                  

                  
                      
                  
                      
                  
                      
                  
                      
                  
                  
                

                

                    Show inline comments
                    
                

        

        

            



	
	
		
 
@@ -3,7 +3,7 @@

			




	
	
	
		
 
import random

			




	
	
	
		
 
from unittest import TestCase

			




	
	
	
		
 

			




	
	
	
		
 
from shamira import _shareByte

			




	
	
	
		
 
from shamira import _share_byte

			




	
	
	
		
 
from shamira import *

			




	
	
	
		
 

			




	
	
	
		
 

			




	
	
		
 
@@ -19,28 +19,28 @@ class TestShamira(TestCase):

			




	
	
	
		
 
	def tearDownClass(cls):

			




	
	
	
		
 
		os.urandom = cls._urandom

			




	
	
	
		
 

			




	
	
	
		
 
	def test_shareByte(self):

			




	
	
	
		
 
	def test_share_byte(self):

			




	
	
	
		
 
		with self.assertRaises(InvalidParams):  # too few shares

			




	
	
	
		
 
			_shareByte(b"a", 5, 4)

			




	
	
	
		
 
			_share_byte(b"a", 5, 4)

			




	
	
	
		
 
		with self.assertRaises(InvalidParams):  # too many shares

			




	
	
	
		
 
			_shareByte(b"a", 5, 255)

			




	
	
	
		
 
			_share_byte(b"a", 5, 255)

			




	
	
	
		
 
		with self.assertRaises(ValueError):  # not castable to int

			




	
	
	
		
 
			_shareByte("x", 2, 3)

			




	
	
	
		
 
			_share_byte("x", 2, 3)

			




	
	
	
		
 

			




	
	
	
		
 
		vals = _shareByte(ord(b"a"), 2, 3)

			




	
	
	
		
 
		vals = _share_byte(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

			




	
	
	
		
 
		self.assertEqual(gf256.get_constant_coef(*points), ord(b"a"))

			




	
	
	
		
 
		self.assertEqual(gf256.get_constant_coef(*points[:2]), ord(b"a"))

			




	
	
	
		
 
		self.assertNotEqual(gf256.get_constant_coef(*points[:1]), ord(b"a"))  # underdetermined => random

			




	
	
	
		
 

			




	
	
	
		
 
	def testGenerateReconstructRaw(self):

			




	
	
	
		
 
	def test_generate_reconstruct_raw(self):

			




	
	
	
		
 
		for (k, n) in [(2, 3), (254, 254)]:

			




	
	
	
		
 
			shares = generateRaw(b"abcd", k, n)

			




	
	
	
		
 
			shares = generate_raw(b"abcd", k, n)

			




	
	
	
		
 
			random.shuffle(shares)

			




	
	
	
		
 
			self.assertEqual(reconstructRaw(*shares[:k]), b"abcd")

			




	
	
	
		
 
			self.assertNotEqual(reconstructRaw(*shares[:k-1]), b"abcd")

			




	
	
	
		
 
			self.assertEqual(reconstruct_raw(*shares[:k]), b"abcd")

			




	
	
	
		
 
			self.assertNotEqual(reconstruct_raw(*shares[:k-1]), b"abcd")

			




	
	
	
		
 

			




	
	
	
		
 
	def testGenerateReconstruct(self):

			




	
	
	
		
 
	def test_generate_reconstruct(self):

			




	
	
	
		
 
		for encoding in ["hex", "b32", "b64"]:

			




	
	
	
		
 
			for secret in [b"abcd", "abcde", "ěščřžý"]:

			




	
	
	
		
 
				for (k, n) in [(2, 3), (254, 254)]:

			




	
	
		
 
@@ -56,13 +56,13 @@ class TestShamira(TestCase):

			




	
	
	
		
 
		with self.assertRaises(DecodingException):

			




	
	
	
		
 
			reconstruct(*shares)

			




	
	
	
		
 

			




	
	
	
		
 
	def testEncode(self):

			




	
	
	
		
 
	def test_encode(self):

			




	
	
	
		
 
		share = (2, b"\x00\x01\x02")

			




	
	
	
		
 
		for (encoding, encodedStr) in [("hex", '000102'), ("b32", 'AAAQE==='), ("b64", 'AAEC')]:

			




	
	
	
		
 
		for (encoding, encoded_str) in [("hex", '000102'), ("b32", 'AAAQE==='), ("b64", 'AAEC')]:

			




	
	
	
		
 
			with self.subTest(enc=encoding):

			




	
	
	
		
 
				self.assertEqual(encode(share, encoding), "2."+encodedStr)

			




	
	
	
		
 
				self.assertEqual(encode(share, encoding), "2."+encoded_str)

			




	
	
	
		
 

			




	
	
	
		
 
	def testDecode(self):

			




	
	
	
		
 
	def test_decode(self):

			




	
	
	
		
 
		with self.assertRaises(MalformedShare):

			




	
	
	
		
 
			decode("AAA")

			




	
	
	
		
 
			decode("1.")

			




	
	
		
 
@@ -95,8 +95,8 @@ class TestShamira(TestCase):

			




	
	
	
		
 
		]:

			




	
	
	
		
 
			with self.subTest(shares=shares):

			




	
	
	
		
 
				with self.assertRaises(DetectionException):

			




	
	
	
		
 
					detectEncoding(shares)

			




	
	
	
		
 
		self.assertEqual(detectEncoding(["10.00010203"]), "hex")

			




	
	
	
		
 
		self.assertEqual(detectEncoding(["2.AAAQEAY="]), "b32")

			




	
	
	
		
 
		self.assertEqual(detectEncoding(["3.AAECAw=="]), "b64")

			




	
	
	
		
 
		self.assertEqual(detectEncoding(["3.AAECAwQF", "1.00010203"]), "b64")

			




	
	
	
		
 
					detect_encoding(shares)

			




	
	
	
		
 
		self.assertEqual(detect_encoding(["10.00010203"]), "hex")

			




	
	
	
		
 
		self.assertEqual(detect_encoding(["2.AAAQEAY="]), "b32")

			




	
	
	
		
 
		self.assertEqual(detect_encoding(["3.AAECAw=="]), "b64")

			




	
	
	
		
 
		self.assertEqual(detect_encoding(["3.AAECAwQF", "1.00010203"]), "b64")

			




        

    



    


    



    



      

      





    
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