Merge pull request #46 from np/check-zk-length

Additionally check for the length of the array of proofs

helios/crypto/algs.py

@@ -547,6 +547,10 @@ class EGCiphertext:
       
       overall_challenge is what all of the challenges combined should yield.
       """
+      if len(plaintexts) != len(proof.proofs):
+        print("bad number of proofs (expected %s, found %s)" % (len(plaintexts), len(proof.proofs)))
+        return False
+
       for i in range(len(plaintexts)):
         # if a proof fails, stop right there
         if not self.verify_encryption_proof(plaintexts[i], proof.proofs[i]):

helios/crypto/elgamal.py

@@ -409,6 +409,10 @@ class Ciphertext:
       
       overall_challenge is what all of the challenges combined should yield.
       """
+      if len(plaintexts) != len(proof.proofs):
+        print("bad number of proofs (expected %s, found %s)" % (len(plaintexts), len(proof.proofs)))
+        return False
+
       for i in range(len(plaintexts)):
         # if a proof fails, stop right there
         if not self.verify_encryption_proof(plaintexts[i], proof.proofs[i]):