Give a more accurate effective key size for 3DES

[tls-check.git] / tls-check

diff --git a/tls-check b/tls-check
index 27651d53855b9a36b970c52434143898eb4a3126..5de58e4f03c8925b110f5014dca8c48bcb81b9c5 100755 (executable)
--- a/tls-check
+++ b/tls-check
@@ -3,7 +3,9 @@ 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
@@ -35,7 +36,17 @@ def finish_progress():
     w, h = terminal_size()
     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(spec="ALL:COMPLEMENTOFALL"):
@@ -86,6 +97,17 @@ class CipherStrength(Enum):
     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:
@@ -102,16 +124,20 @@ class CipherPropsProvider:
         assert '\n' not in cipherInfo
         cipherInfoFields = cipherInfo.split()
         # get # of bits
-        bitMatch = re.match(r'^Enc=[0-9A-Za-z]+\(([0-9]+)\)$', cipherInfoFields[4])
-        if bitMatch is None:
+        encMatch = re.match(r'^Enc=([0-9A-Za-z]+)\(([0-9]+)\)$', cipherInfoFields[4])
+        if encMatch is None:
             raise Exception("Unexpected OpenSSL output: Cannot determine encryption strength from {1}\nComplete output: {0}".format(cipherInfo, cipherInfoFields[4]))
-        bits = int(bitMatch.group(1))
+        encCipher = encMatch.group(1)
+        bits = int(encMatch.group(2))
+        if encCipher == '3DES':
+            # OpenSSL gives the key size, which however for 3DES is a totally bad estimate
+            bits = int(bits*2/3)
         # figure out whether the cipher is pfs
-        kxMatch = re.match(r'^Kx=([0-9A-Z/]+)$', cipherInfoFields[2])
+        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])
+            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', 'ECDH')
+        isPfs = kx in ('DH', 'DH(512)', 'ECDH')
         # determine security level
         isExp = cipher in self.exp
         isLow = cipher in self.low
@@ -175,5 +201,7 @@ if __name__ == "__main__":
             for cipher, supported in ciphers.items():
                 if supported:
                     cipherProps = propsProvider.getProps(cipher)
-                    print("    {0} ({1}, {2} bits, {3})".format(cipher, cipherProps.strength.name, cipherProps.bits, "FS" if cipherProps.isPfs else "not FS"))
+                    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()