# HG changeset patch
# User Laman
# Date 2017-10-01 17:51:06
# Node ID 735b9c2a61e94b93c67d17490920a7ee00667740
# Parent  6511b6f4f6c0d3acec605de96f36a3ba15be3fef

cli catching thrown exceptions

diff --git a/src/cli.py b/src/cli.py
--- a/src/cli.py
+++ b/src/cli.py
@@ -12,7 +12,7 @@ def run():
 	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)
@@ -45,14 +45,20 @@ def buildJoinParser(parser):
 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):
diff --git a/src/condensed.py b/src/condensed.py
--- a/src/condensed.py
+++ b/src/condensed.py
@@ -99,7 +99,7 @@ def run():
 
 	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"))
 
@@ -107,5 +107,10 @@ def run():
 	args.func(args)
 
 
+def _reconstruct(args):
+	try: print(reconstruct(*args.share))
+	except ValueError as e: print("operation failed: ",e)
+
+
 if __name__=="__main__":
 	run()
diff --git a/src/shamira.py b/src/shamira.py
--- a/src/shamira.py
+++ b/src/shamira.py
@@ -9,7 +9,8 @@ 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
diff --git a/src/tests/test_shamira.py b/src/tests/test_shamira.py
--- a/src/tests/test_shamira.py
+++ b/src/tests/test_shamira.py
@@ -20,9 +20,9 @@ class TestShamira(TestCase):
 		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)