Cisco UnCipher - Reverse Type 7 Passwords

Author: ticoombs

cisco-uncipher.py

@@ -0,0 +1,34 @@
+"""
+Uncipher Cisco type 7 ciphered passwords
+Usage: python uncipher.py <pass> where <pass> is the text of the type 7 password
+Example:
+$ python uncipher.py 094F4F1D1A0403
+catcat
+"""
+import fileinput
+import sys
+
+global key
+key = [0x64, 0x73, 0x66, 0x64, 0x3b, 0x6b, 0x66, 0x6f, 0x41,
+ 0x2c, 0x2e, 0x69, 0x79, 0x65, 0x77, 0x72, 0x6b, 0x6c,
+ 0x64, 0x4a, 0x4b, 0x44, 0x48, 0x53, 0x55, 0x42]
+
+def uncipher(ciphertext):
+    try:
+        index = int(pw[:2],16)
+    except ValueError:
+        return ''
+    pw_text = ciphertext[2:].rstrip()
+    pw_hex_values = [pw_text[start:start+2] for start in range(0,len(pw_text),2)]
+    pw_chars = [chr(key[index+i] ^ int(pw_hex_values[i],16)) for i in range(0,len(pw_hex_values))]
+    pw_plaintext = ''.join(pw_chars)
+    return pw_plaintext
+
+try:
+    for pw in fileinput.input():
+
+        print uncipher(pw)
+except:
+    pw = sys.argv[1]
+    print uncipher(pw)
+