def _derive_pubkey(self):
# derive EC public key instance from self._key
if self._key == None:
return False
membuff = BIO.MemoryBuffer()
self._key.save_pub_key_bio(membuff) #(filename)
self._pubkey = EC.load_pub_key_bio(membuff) #filename)
def _constructEcFromRawKey(self, rawPublicKey):
assert(len(rawPublicKey) == 64)
bytes1 = a2b_hex("3059301306072a8648ce3d020106082a8648ce3d03010703420004")
asn1KeyBytes = bytes1 + rawPublicKey
pemPubKeyBytes = PEMEncoder(asn1KeyBytes).getEncoded("PUBLIC KEY")
return EC.load_pub_key_bio(BIO.MemoryBuffer(pemPubKeyBytes))
def _constructEcFromRawKey(self, rawPublicKey):
assert (len(rawPublicKey) == 64)
bytes1 = a2b_hex(
"3059301306072a8648ce3d020106082a8648ce3d03010703420004")
asn1KeyBytes = bytes1 + rawPublicKey
pemPubKeyBytes = PEMEncoder(asn1KeyBytes).getEncoded("PUBLIC KEY")
return EC.load_pub_key_bio(BIO.MemoryBuffer(pemPubKeyBytes))
def __init__(self, mai):
"""Initialize the structure with a MetaAppInstance.
Arguments:
* ``mai``: the MetaAppInstance whose public key is used to verify
signatures
"""
self.mai = mai
self._ecs = []
bio = BIO.MemoryBuffer(str(self.mai.pubkey_ec))
self._ecs.append(EC.load_pub_key_bio(bio))
def DSKE(connection, sid, participants, phase=None):
"""
Generate ECDH Keypair and perform Key Exchange with all other participants
@param connection: Current CRYPTO connection
@type connection: CRYPTOConnection instance
@param sid: Current SessionID
@type sid: Integer
@param phase: Phase of the DSKE routine
@type phase: integer in range (0,2)
"""
newlist = []
# Create public/private keypairs and add them to keytable
# Send keys out to participants and wait for responses
if phase == 0:
connection.keypair = EC_GenerateKey(744)
connection.private_pem = EC_Private(connection.keypair)
connection.public_pem = EC_Public(connection.keypair)
z = EC.load_pub_key_bio(BIO.MemoryBuffer(connection.public_pem))
public_bin = ec_to_public_bin(connection.keypair)
connection.keytable.update({broadcast.getPrefs():public_bin.encode("HEX")})
broadcast.Broadcast(participants, SendKey(public_bin.encode("HEX")))
return None
# Once all public keys are received, sort them and take the hash
# Broadcast to all users to confirm agreement
elif phase == 1:
pubkeys = [y for x,y in connection.keytable.items()]
pubkeys.sort()
pubkeys = "".join(pubkeys)
hash_object = hashlib.sha256(pubkeys)
hex_dig = hash_object.hexdigest()
connection.keyhash = hex_dig
connection.associationtable.update({broadcast.getPrefs():connection.keyhash})
broadcast.Broadcast(connection.users, SendAssociation(hex_dig))
return None
#
else:
i = 0
hashes = [y for x,y in connection.associationtable.items()]
for y in hashes:
if not y == connection.keyhash:
i = i+1
if i == 0:
return 1
try:
if type(ciphertext) == str:
j = serializer.loads(ciphertext)
else:
j = ciphertext
if j['type'] != 'EC_Encrypted':
raise Exception("Input may not be the intending ciphertext.")
publickey = j['public_key']
ciphertext= j['ciphertext']
except Exception,e:
raise Exception("Bad EC ciphertext format.")
try:
# Read the temp. key. First write to a file.
membuff = BIO.MemoryBuffer()
membuff.write(publickey)
tempkey = EC.load_pub_key_bio(membuff)
# Combine this temp. key with our private key, and get Shared Secret.
sharedsecret = self._key.compute_dh_key(tempkey)
except Exception,e:
raise Exception("Unable to load public key. Error is [%s]." % e)
return decryptor(sharedsecret,ciphertext)
def load_publickey(self,publickey):
# Try parse the public key info.
try:
if type(publickey) == str:
j = serializer.loads(publickey)
else:
j = publickey
if j['type'] != 'EC_Public_Key':
raise Exception("This is not a public key thus cannot be loaded.")
if self._curves_id.has_key(j['curve']):
def ec_from_public_pem(pem):
"Get the EC from a public PEM."
return EC.load_pub_key_bio(BIO.MemoryBuffer(pem))
def ec_from_public_pem(pem):
"Get the EC from a public PEM."
return EC.load_pub_key_bio(BIO.MemoryBuffer(pem))
def PubKey_from_PEM(self, pemkey):
m = BIO.MemoryBuffer(pemkey)
self._key = EC.load_pub_key_bio(m)
def PubKey_from_PEM(self, pemkey):
m = BIO.MemoryBuffer(pemkey)
self._key = EC.load_pub_key_bio(m)
