def get_choices(self, encoded, nr_answers, answers=None, params=None):
max_encoded = core.gamma_encoding_max(nr_answers)
if encoded > max_encoded:
choices = []
else:
selection = core.gamma_decode(encoded, nr_answers)
choices = to_absolute_answers(selection, nr_answers)
return choices
def get_choices(self, encoded, nr_answers, answers=None, params=None):
max_encoded = core.gamma_encoding_max(nr_answers)
if encoded > max_encoded:
choices = []
else:
selection = core.gamma_decode(encoded, nr_answers)
choices = to_absolute_answers(selection, nr_answers)
return choices
def main_verify(sigfile, randomness=None, plaintext=None):
with open(sigfile) as f:
signature = f.read()
vote_info = verify_vote_signature(signature)
signed_vote, crypto, trustees, candidates, comments = vote_info
eb = signed_vote['encrypted_ballot']
public = eb['public']
modulus, generator, order = crypto
beta = eb['beta']
print 'VERIFIED: Authentic Signature'
if randomness is None:
return
nr_candidates = len(candidates)
encoded = decrypt_with_randomness(modulus, generator, order,
public, beta, randomness)
if plaintext is not None:
if plaintext != encoded:
print 'FAILED: Plaintext Mismatch'
ct = encrypt(plaintext, modulus, generator, order, randomness)
_alpha, _beta, _randomness = ct
alpha = eb['alpha']
if (alpha, beta) != (_alpha, _beta):
print 'FAILED: Invalid Encryption'
max_encoded = gamma_encoding_max(nr_candidates) + 1
print "plaintext: %d" % encoded
print "max plaintext: %d" % max_encoded
if encoded > max_encoded:
print "FAILED: Invalid Vote. Cannot decode."
return
selection = gamma_decode(encoded, nr_candidates)
choices = to_absolute_answers(selection, nr_candidates)
print ""
for i, o in enumerate(choices):
print "%d: [%d] %s" % (i, o, candidates[o])
print ""
def main_verify(sigfile, randomness=None, plaintext=None):
with open(sigfile) as f:
signature = f.read()
vote_info = verify_vote_signature(signature)
signed_vote, crypto, trustees, candidates, comments = vote_info
eb = signed_vote['encrypted_ballot']
public = eb['public']
modulus, generator, order = crypto
beta = eb['beta']
print 'VERIFIED: Authentic Signature'
if randomness is None:
return
nr_candidates = len(candidates)
encoded = decrypt_with_randomness(modulus, generator, order,
public, beta, randomness)
if plaintext is not None:
if plaintext != encoded:
print 'FAILED: Plaintext Mismatch'
ct = encrypt(plaintext, modulus, generator, order, randomness)
_alpha, _beta, _randomness = ct
alpha = eb['alpha']
if (alpha, beta) != (_alpha, _beta):
print 'FAILED: Invalid Encryption'
max_encoded = gamma_encoding_max(nr_candidates) + 1
print "plaintext: %d" % encoded
print "max plaintext: %d" % max_encoded
if encoded > max_encoded:
print "FAILED: Invalid Vote. Cannot decode."
return
selection = gamma_decode(encoded, nr_candidates)
choices = to_absolute_answers(selection, nr_candidates)
print ""
for i, o in enumerate(choices):
print "%d: [%d] %s" % (i, o, candidates[o])
print ""