initial code for dumping imessages in a reasonable format

dump-imessages/iphone-dataprotection/python_scripts/keychain/keychain3.py

@@ -0,0 +1,44 @@
+from keychain import Keychain
+from crypto.aes import AESdecryptCBC, AESencryptCBC
+import hashlib
+
+class Keychain3(Keychain):
+    def __init__(self, filename, key835=None):
+        Keychain.__init__(self, filename)
+        self.key835 = key835
+        
+    def decrypt_data(self, data):
+        if data == None:
+            return ""
+        data = str(data)
+        
+        if not self.key835:
+            print "Key 835 not availaible"
+            return ""
+        
+        data = AESdecryptCBC(data[16:], self.key835, data[:16], padding=True)
+        
+        #data_column = iv + AES128_K835(iv, data + sha1(data))
+        if hashlib.sha1(data[:-20]).digest() != data[-20:]:
+            print "data field hash mismatch : bad key ?"
+            return "ERROR decrypting data : bad key ?"
+
+        return data[:-20]
+    
+    def change_key835(self, newkey):
+        tables = {"genp": "SELECT rowid, data FROM genp",
+                  "inet": "SELECT rowid, data FROM inet",
+                  "cert": "SELECT rowid, data FROM cert",
+                  "keys": "SELECT rowid, data FROM keys"}
+        
+        for t in tables.keys():
+            for row in self.conn.execute(tables[t]):
+                rowid = row["rowid"]
+                data = str(row["data"])
+                iv = data[:16]
+                data = AESdecryptCBC(data[16:], self.key835, iv)
+                data = AESencryptCBC(data, newkey, iv)
+                data = iv + data
+                data = buffer(data)
+                self.conn.execute("UPDATE %s SET data=? WHERE rowid=?" % t, (data, rowid))
+        self.conn.commit()