def get_cryptosystem():
"""
This function returns a predetermined EGCryptoSystem object.
The EGCryptoSystem object is loaded from a resource file and guaranteed to
be always the same, at least for same execution of the test suite. The
cryptosystem is also cached in memory for quicker access.
"""
global _cryptosys
# Check if we have already loaded a cryptosystem for this test run
if (_cryptosys == None):
# If not, load it now:
# Construct the path to the cryptosystem test resource file
cryptosys_file = os.path.join(
os.path.dirname(__file__),
"TestThresholdEncryptionSetUp.resources",
"test1024bits.pvcryptosys")
# Load the cryptosystem from file
_cryptosys = EGCryptoSystem.from_file(cryptosys_file)
# Return the cached cryptosystem
# (Note: this is the original reference, not a deepcopy, tests using the
# cryptosystem object should treat it as read-only to preserve isolation)
return _cryptosys
def test_commitmet_adding(self):
"""
Creates a new ThresholdEncryptionSetUp and try to add a trustee c
commitment
"""
cryptosystem = get_cryptosystem()
commitments = []
# Generate a new instance of ThresholdEncryptionSetUp
tSetUp = ThresholdEncryptionSetUp(cryptosystem, self.num_trustees,
self.threshold)
# Adding the keys from trustees
for i in range(self.num_trustees):
tSetUp.add_trustee_public_key(i, self.trustees[i].public_key)
# Generate and add a valid commitment
commitment = tSetUp.generate_commitment()
tSetUp.add_trustee_commitment(0, commitment)
#The commitment for trustee 0 must be the same we just add
self.assertEqual(tSetUp._trustees_commitments[0], commitment)
# add_trustee_commitmnet must raise ValueError with invalid trustee
# values (-1 and self.num_trustees+1)
self.assertRaises(ValueError, tSetUp.add_trustee_commitment, -1,
commitment)
self.assertRaises(ValueError, tSetUp.add_trustee_commitment,
self.num_trustees + 1, commitment)
# Change commitment.num_trustees value to try erros
commitment.num_trustees = self.num_trustees + 1
# add_trustee_commitmnet must raise IncompatibleCommitmentError when
# the commitment has diferent num_trustees value
self.assertRaises(IncompatibleCommitmentError,
tSetUp.add_trustee_commitment, 1, commitment)
# Change commitment.threshold value to try erros
commitment.num_trustees = self.num_trustees
commitment.threshold = self.threshold + 1
# add_trustee_commitmnet must raise IncompatibleCommitmentError when
# the commitment has diferent theshold value
self.assertRaises(IncompatibleCommitmentError,
tSetUp.add_trustee_commitment, 1, commitment)
# Test what happens with invalid cryptosystem
# Create another cryptosystem
second_cryptosys_file = os.path.join(
os.path.dirname(__file__),
"TestThresholdEncryptionSetUp.resources",
"test1024bits_second.pvcryptosys")
# Load the cryptosystem from file
second_cryptosys = EGCryptoSystem.from_file(second_cryptosys_file)
commitment.threshold = self.threshold
commitment.cryptosystem = second_cryptosys
# Must raise IncompatibleCommitmentError with diferent cryptosys
self.assertRaises(IncompatibleCommitmentError,
tSetUp.add_trustee_commitment, 1, commitment)
def test_commitmet_adding(self):
"""
Creates a new ThresholdEncryptionSetUp and try to add a trustee c
commitment
"""
cryptosystem = get_cryptosystem()
commitments = []
# Generate a new instance of ThresholdEncryptionSetUp
tSetUp = ThresholdEncryptionSetUp(cryptosystem,
self.num_trustees, self.threshold)
# Adding the keys from trustees
for i in range(self.num_trustees):
tSetUp.add_trustee_public_key(i, self.trustees[i].public_key)
# Generate and add a valid commitment
commitment = tSetUp.generate_commitment()
tSetUp.add_trustee_commitment(0, commitment)
#The commitment for trustee 0 must be the same we just add
self.assertEqual(tSetUp._trustees_commitments[0], commitment)
# add_trustee_commitmnet must raise ValueError with invalid trustee
# values (-1 and self.num_trustees+1)
self.assertRaises(ValueError, tSetUp.add_trustee_commitment,
-1, commitment)
self.assertRaises(ValueError, tSetUp.add_trustee_commitment,
self.num_trustees+1, commitment)
# Change commitment.num_trustees value to try erros
commitment.num_trustees = self.num_trustees +1
# add_trustee_commitmnet must raise IncompatibleCommitmentError when
# the commitment has diferent num_trustees value
self.assertRaises(IncompatibleCommitmentError,
tSetUp.add_trustee_commitment, 1, commitment)
# Change commitment.threshold value to try erros
commitment.num_trustees = self.num_trustees
commitment.threshold = self.threshold+1
# add_trustee_commitmnet must raise IncompatibleCommitmentError when
# the commitment has diferent theshold value
self.assertRaises(IncompatibleCommitmentError,
tSetUp.add_trustee_commitment, 1, commitment)
# Test what happens with invalid cryptosystem
# Create another cryptosystem
second_cryptosys_file = os.path.join(os.path.dirname(__file__),
"TestThresholdEncryptionSetUp.resources",
"test1024bits_second.pvcryptosys")
# Load the cryptosystem from file
second_cryptosys = EGCryptoSystem.from_file(second_cryptosys_file)
commitment.threshold = self.threshold
commitment.cryptosystem = second_cryptosys
# Must raise IncompatibleCommitmentError with diferent cryptosys
self.assertRaises(IncompatibleCommitmentError,
tSetUp.add_trustee_commitment, 1, commitment)
def get_cryptosystem():
"""
This function returns a predetermined EGCryptoSystem object.
The EGCryptoSystem object is loaded from a resource file and guaranteed to
be always the same, at least for same execution of the test suite. The
cryptosystem is also cached in memory for quicker access.
"""
global _cryptosys
# Check if we have already loaded a cryptosystem for this test run
if(_cryptosys == None):
# If not, load it now:
# Construct the path to the cryptosystem test resource file
cryptosys_file = os.path.join(os.path.dirname(__file__),
"TestBasicEncryption.resources",
"test1024bits.pvcryptosys")
# Load the cryptosystem from file
_cryptosys = EGCryptoSystem.from_file(cryptosys_file)
# Return the cached cryptosystem
# (Note: this is the original reference, not a deepcopy, tests using the
# cryptosystem object should treat it as read-only to preserve isolation)
return _cryptosys
def test_partial_decryption(self):
"""
Create a ciphertext with the threshold public key and decrypt it and
create others ciphertext to prove IncompatibleCiphertextError
"""
tprk = self.tSetUp.generate_private_key(0,
self.trustees[0].private_key)
text_to_encrypt_dir = os.path.join(
os.path.dirname(__file__), "TestThresholdPrivateKey.resources")
text_to_encrypt = os.path.join(text_to_encrypt_dir, "text_to_encrypt")
text_encrypted = self.tpkey.encrypt_text(text_to_encrypt)
# Decrypt the file created with our public key must be fine
tprk.generate_partial_decryption(text_encrypted)
# Create another ThresholdEcryptuonSetUp with other 1024 bits
# cryptosys to create a cypthertext that cant be decrypted
second_cryptosys_file = os.path.join(
os.path.dirname(__file__),
"TestThresholdEncryptionSetUp.resources",
"test1024bits_second.pvcryptosys")
# Load the cryptosystem from file
second_cryptosys = EGCryptoSystem.from_file(second_cryptosys_file)
secondtSetUp = ThresholdEncryptionSetUp(second_cryptosys,
self.num_trustees,
self.threshold)
# Adding the keys from trustees for 2ndsetUp
for i in range(self.num_trustees):
secondtSetUp.add_trustee_public_key(i, self.trustees[i].public_key)
secondcommitments = []
# Generate commitmes for trustees for 2ndsetUp
for i in range(self.num_trustees):
secondcommitments.append(secondtSetUp.generate_commitment())
# Adding the secont trustees commitments
for i in range(self.num_trustees):
secondtSetUp.add_trustee_commitment(i, secondcommitments[i])
# Generate secon cryptosis publickey
secondtpkey = secondtSetUp.generate_public_key()
# Encrypt the file with the secon cryptosis publickey
secondtext_encrypted = secondtpkey.encrypt_text(text_to_encrypt)
# Try to decryp something created with other ThresholdEcryptuonSetUp
# must raise IncompatibleCiphertextError
self.assertRaises(IncompatibleCiphertextError,
tprk.generate_partial_decryption,
secondtext_encrypted)
# Create another ThresholdEcryptuonSetUp with other 512 bits
# cryptosys to create a cypthertext that cant be decrypted
third_cryptosys_file = os.path.join(
os.path.dirname(__file__),
"TestThresholdEncryptionSetUp.resources",
"test512bits.pvcryptosys")
# Load the cryptosystem from file
third_cryptosys = EGCryptoSystem.from_file(third_cryptosys_file)
thirdtSetUp = ThresholdEncryptionSetUp(third_cryptosys,
self.num_trustees,
self.threshold)
# Adding the keys from trustees for 2ndsetUp
for i in range(self.num_trustees):
thirdtSetUp.add_trustee_public_key(i, self.trustees[i].public_key)
thirdcommitments = []
# Generate commitmes for trustees for 2ndsetUp
for i in range(self.num_trustees):
thirdcommitments.append(thirdtSetUp.generate_commitment())
# Adding the secont trustees commitments
for i in range(self.num_trustees):
thirdtSetUp.add_trustee_commitment(i, thirdcommitments[i])
# Generate secon cryptosis publickey
thirdtpkey = thirdtSetUp.generate_public_key()
# Encrypt the file with the secon cryptosis publickey
thirdtext_encrypted = thirdtpkey.encrypt_text(text_to_encrypt)
# Try to decryp something created with other ThresholdEcryptuonSetUp
# must raise IncompatibleCiphertextError
self.assertRaises(IncompatibleCiphertextError,
tprk.generate_partial_decryption,
thirdtext_encrypted)
def test_partial_decryption(self):
"""
Create a ciphertext with the threshold public key and decrypt it and
create others ciphertext to prove IncompatibleCiphertextError
"""
tprk = self.tSetUp.generate_private_key(0, self.trustees[0].private_key)
text_to_encrypt_dir = os.path.join(os.path.dirname(__file__),
"TestThresholdPrivateKey.resources")
text_to_encrypt = os.path.join(text_to_encrypt_dir, "text_to_encrypt")
text_encrypted = self.tpkey.encrypt_text(text_to_encrypt)
# Decrypt the file created with our public key must be fine
tprk.generate_partial_decryption(text_encrypted)
# Create another ThresholdEcryptuonSetUp with other 1024 bits
# cryptosys to create a cypthertext that cant be decrypted
second_cryptosys_file = os.path.join(os.path.dirname(__file__),
"TestThresholdEncryptionSetUp.resources",
"test1024bits_second.pvcryptosys")
# Load the cryptosystem from file
second_cryptosys = EGCryptoSystem.from_file(second_cryptosys_file)
secondtSetUp = ThresholdEncryptionSetUp(second_cryptosys,
self.num_trustees, self.threshold)
# Adding the keys from trustees for 2ndsetUp
for i in range(self.num_trustees):
secondtSetUp.add_trustee_public_key(i, self.trustees[i].public_key)
secondcommitments = []
# Generate commitmes for trustees for 2ndsetUp
for i in range(self.num_trustees):
secondcommitments.append(secondtSetUp.generate_commitment())
# Adding the secont trustees commitments
for i in range(self.num_trustees):
secondtSetUp.add_trustee_commitment(i, secondcommitments[i])
# Generate secon cryptosis publickey
secondtpkey = secondtSetUp.generate_public_key()
# Encrypt the file with the secon cryptosis publickey
secondtext_encrypted = secondtpkey.encrypt_text(text_to_encrypt)
# Try to decryp something created with other ThresholdEcryptuonSetUp
# must raise IncompatibleCiphertextError
self.assertRaises(IncompatibleCiphertextError,
tprk.generate_partial_decryption, secondtext_encrypted)
# Create another ThresholdEcryptuonSetUp with other 512 bits
# cryptosys to create a cypthertext that cant be decrypted
third_cryptosys_file = os.path.join(os.path.dirname(__file__),
"TestThresholdEncryptionSetUp.resources",
"test512bits.pvcryptosys")
# Load the cryptosystem from file
third_cryptosys = EGCryptoSystem.from_file(third_cryptosys_file)
thirdtSetUp = ThresholdEncryptionSetUp(third_cryptosys,
self.num_trustees, self.threshold)
# Adding the keys from trustees for 2ndsetUp
for i in range(self.num_trustees):
thirdtSetUp.add_trustee_public_key(i, self.trustees[i].public_key)
thirdcommitments = []
# Generate commitmes for trustees for 2ndsetUp
for i in range(self.num_trustees):
thirdcommitments.append(thirdtSetUp.generate_commitment())
# Adding the secont trustees commitments
for i in range(self.num_trustees):
thirdtSetUp.add_trustee_commitment(i, thirdcommitments[i])
# Generate secon cryptosis publickey
thirdtpkey = thirdtSetUp.generate_public_key()
# Encrypt the file with the secon cryptosis publickey
thirdtext_encrypted = thirdtpkey.encrypt_text(text_to_encrypt)
# Try to decryp something created with other ThresholdEcryptuonSetUp
# must raise IncompatibleCiphertextError
self.assertRaises(IncompatibleCiphertextError,
tprk.generate_partial_decryption, thirdtext_encrypted)
