+# cipher classification
+class CipherStrength(Enum):
+ unknown = -1
+ high = 3
+
+ def colorName(self):
+ if self.value == CipherStrength.high.value:
+ return ConsoleFormat.color(self.name, ConsoleFormat.GREEN)
+ else:
+ return ConsoleFormat.color(self.name, ConsoleFormat.YELLOW)
+
+CipherProps = namedtuple('CipherProps', 'bits, strength, isPfs')
+
+class CipherPropsProvider:
+ def __init__(self):
+ self.high = set(list_ciphers("HIGH"))
+ self.props = {}
+
+ def getProps(self, protocol, cipher):
+ # strip the sub-version-number from the protocol
+ pos = protocol.find('_')
+ if pos >= 0:
+ protocol = protocol[:pos]
+ # as OpenSSL about this cipher
+ cipherInfo = subprocess.check_output(["openssl", "ciphers", "-v", "-"+protocol, cipher]).decode('UTF-8').strip()
+ cipherInfoFields = None
+ for line in cipherInfo.split('\n'):
+ line = line.split()
+ if line[0] == cipher:
+ cipherInfoFields = line
+ break
+ if cipherInfoFields is None:
+ raise Exception("Cannot determine cipher properties of {0} (protocol: {1})".format(cipher, protocol))
+ # get # of bits
+ encMatch = re.match(r'^Enc=([0-9A-Za-z]+)\(([0-9]+)\)$', cipherInfoFields[4])
+ if encMatch is None:
+ raise Exception("Unexpected OpenSSL output: Cannot determine encryption strength from {1}\nComplete output: {0}".format(cipherInfo, cipherInfoFields[4]))
+ encCipher = encMatch.group(1)
+ bits = int(encMatch.group(2))
+ if encCipher == '3DES':
+ # OpenSSL gives the key size, which however for 3DES is a totally bad estimate
+ bits = int(bits*2/3)
+ # figure out whether the cipher is pfs
+ kxMatch = re.match(r'^Kx=([0-9A-Z/()]+)$', cipherInfoFields[2])
+ if kxMatch is None:
+ raise Exception("Unexpected OpenSSL output: Cannot determine key-exchange method from {1}\nComplete output: {0}".format(cipherInfo, cipherInfoFields[2]))
+ kx = kxMatch.group(1)
+ isPfs = kx in ('DH', 'DH(512)', 'ECDH')
+ # determine security level
+ if cipher in self.high:
+ strength = CipherStrength.high
+ else:
+ strength = CipherStrength.unknown
+ # done!
+ return CipherProps(bits=bits, strength=strength, isPfs=isPfs)
+
+# main program