X-Git-Url: https://git.ralfj.de/tls-check.git/blobdiff_plain/ac0e7156a0d16de49f07c4d56c988c52393e2ecc..bf72211191deb4127ba827fef34f13756e23851f:/tls-check

diff --git a/tls-check b/tls-check
index 9d84f42..f757bdb 100755
--- a/tls-check
+++ b/tls-check
@@ -1,9 +1,11 @@
 #!/usr/bin/python3
-import subprocess, sys, argparse
-from collections import OrderedDict
+import subprocess, sys, argparse, time, re
+from collections import OrderedDict, namedtuple
 from enum import Enum
 
-# progress bar
+# progress bar and other console output fun
+STATE_WIDTH = 30
+
 def terminal_size():
     import fcntl, termios, struct
     try:
@@ -24,7 +26,6 @@ def compute_frac(fracs):
     return frac
 
 def print_progress(state, fracs):
-    STATE_WIDTH = 30
     w, h = terminal_size()
     if w < STATE_WIDTH+10: return # not a (wide enough) terminal
     bar_width = w-STATE_WIDTH-3
@@ -36,12 +37,25 @@ def finish_progress():
     sys.stdout.write('\r'+(' '*w)+'\r')
     sys.stdout.flush()
 
+class ConsoleFormat:
+    BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE = range(8)
+    RESET_SEQ = "\033[0m"
+    COLOR_SEQ = "\033[1;3%dm"
+    BOLD_SEQ  = "\033[1m"
+    
+    @staticmethod
+    def color(text, color):
+        return (ConsoleFormat.COLOR_SEQ % color) + text + ConsoleFormat.RESET_SEQ
+
+
 # cipher check
-def list_ciphers():
-    ciphers = subprocess.check_output(["openssl", "ciphers", "ALL:COMPLEMENTOFALL"]).decode('UTF-8').strip()
+def list_ciphers(spec="ALL:COMPLEMENTOFALL"):
+    ciphers = subprocess.check_output(["openssl", "ciphers", spec]).decode('UTF-8').strip()
     return ciphers.split(':')
 
-def test_cipher(host, port, protocol, cipher = None, options=[]):
+def test_cipher(host, port, protocol, cipher = None, wait_time=0, options=[]):
+    # throttle
+    time.sleep(wait_time/1000)
     try:
         if cipher is not None:
             options = ["-cipher", cipher]+options
@@ -52,34 +66,111 @@ def test_cipher(host, port, protocol, cipher = None, options=[]):
     else:
         return True
 
-def test_protocol(host, port, protocol, ciphers, base_frac, options=[]):
-    if test_cipher(host, port, protocol, options=options):
+def test_protocol(host, port, protocol, ciphers, base_frac, wait_time=0, options=[]):
+    if test_cipher(host, port, protocol, wait_time=wait_time, options=options):
         # the protocol is supported
         results = OrderedDict()
         for i in range(len(ciphers)):
             cipher = ciphers[i]
             print_progress(protocol+" "+cipher, base_frac+[(i, len(ciphers))])
-            results[cipher] = test_cipher(host, port, protocol, cipher, options)
+            results[cipher] = test_cipher(host, port, protocol, cipher=cipher, wait_time=wait_time, options=options)
         return results
     else:
         # it is not supported
         return None
 
-def test_host(host, port, options=[]):
+def test_host(host, port, wait_time=0, options=[]):
     ciphers = list_ciphers()
     results = OrderedDict()
     protocols = ('ssl2', 'ssl3', 'tls1', 'tls1_1', 'tls1_2')
     for i in range(len(protocols)):
         protocol = protocols[i]
         print_progress(protocol, [(i, len(protocols))])
-        results[protocol] = test_protocol(host, port, protocol, ciphers, [(i, len(protocols))], options)
+        results[protocol] = test_protocol(host, port, protocol, ciphers, [(i, len(protocols))], wait_time, options)
     finish_progress()
     return results
 
+# cipher classification
+class CipherStrength(Enum):
+    unknown = -1
+    exp = 0
+    low = 1
+    medium = 2
+    high = 3
+    
+    def colorName(self):
+        if self == CipherStrength.unknown:
+            return self.name
+        elif self.value == CipherStrength.high.value:
+            return ConsoleFormat.color(self.name, ConsoleFormat.GREEN)
+        elif self.value == CipherStrength.medium.value:
+            return ConsoleFormat.color(self.name, ConsoleFormat.YELLOW)
+        else:
+            return ConsoleFormat.color(self.name, ConsoleFormat.RED)
+
+CipherProps = namedtuple('CipherProps', 'bits, strength, isPfs')
+
+class CipherPropsProvider:
+    def __init__(self):
+        self.exp = set(list_ciphers("EXP"))
+        self.low = set(list_ciphers("LOW"))
+        self.medium = set(list_ciphers("MEDIUM"))
+        self.high = set(list_ciphers("HIGH"))
+        self.props = {}
+    
+    def __getProps(self, cipher):
+        # as OpenSSL about this cipher
+        cipherInfo = subprocess.check_output(["openssl", "ciphers", "-v", cipher]).decode('UTF-8').strip()
+        assert '\n' not in cipherInfo
+        cipherInfoFields = cipherInfo.split()
+        # 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
+        isExp = cipher in self.exp
+        isLow = cipher in self.low
+        isMedium = cipher in self.medium
+        isHigh = cipher in self.high
+        assert isExp+isLow+isMedium+isHigh <= 1, "Cipher is more than one from EXP, LOW, MEDIUM, HIGH"
+        if isExp:
+            strength = CipherStrength.exp
+        elif isLow:
+            strength = CipherStrength.low
+        elif isMedium:
+            strength = CipherStrength.medium
+        elif isHigh:
+            strength = CipherStrength.high
+        else:
+            strength = CipherStrength.unknown
+        # done!
+        return CipherProps(bits=bits, strength=strength, isPfs=isPfs)
+    
+    def getProps(self, cipher):
+        if cipher in self.props:
+            return self.props[cipher]
+        props = self.__getProps(cipher)
+        self.props[cipher] = props
+        return props
+
+# main program
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description='Check TLS ciphers supported by a host')
     parser.add_argument("--starttls", dest="starttls",
                         help="Use a STARTTLS variant to establish the TLS connection. Possible values include smpt, imap, xmpp.")
+    parser.add_argument("--wait-time", "-t", dest="wait_time", default="10",
+                        help="Time (in ms) to wait between two connections to the server. Default is 10ms.")
     parser.add_argument("host", metavar='HOST[:PORT]',
                         help="The host to check")
     args = parser.parse_args()
@@ -91,15 +182,17 @@ if __name__ == "__main__":
         host = args.host
         port = 443
     
-    # get options
+    # get options and other stuff
+    wait_time = float(args.wait_time)
     options = []
     if args.starttls is not None:
         options += ['-starttls', args.starttls]
     
     # run the test
-    results = test_host(host, port, options)
+    results = test_host(host, port, wait_time, options)
     
     # print the results
+    propsProvider = CipherPropsProvider()
     for protocol, ciphers in results.items():
         print(protocol+":")
         if ciphers is None:
@@ -107,5 +200,8 @@ if __name__ == "__main__":
         else:
             for cipher, supported in ciphers.items():
                 if supported:
-                    print("    "+cipher)
+                    cipherProps = propsProvider.getProps(cipher)
+                    fsText = ConsoleFormat.color("FS", ConsoleFormat.GREEN) if cipherProps.isPfs else ConsoleFormat.color("no FS", ConsoleFormat.RED)
+                    bitColor = ConsoleFormat.GREEN if cipherProps.bits >= 128 else (ConsoleFormat.YELLOW if cipherProps.bits >= 100 else ConsoleFormat.RED)
+                    print("    {0} ({1}, {2}, {3})".format(cipher.ljust(STATE_WIDTH), cipherProps.strength.colorName(), ConsoleFormat.color(str(cipherProps.bits)+" bits", bitColor), fsText))
         print()