Stuff

eq3crypto.py

@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+from Crypto.Cipher import AES
+
+def dumpNum(n):
+    s = ""
+    for v in n:
+        if len(s) > 0:
+            s = s + " "
+        s = s + str(v)
+    print(s)
+
+def xor_bytes(a,b):
+    z = []
+    for v in a:
+        z.append(v ^ b[len(z)])
+    return bytes(z)
+
+def uInt16ToBytes(a):
+    return bytes([a >> 8, a & 0xff])
+
+def getNonce(msgid, sessNonce, seccnt):
+    return bytes([msgid]) + sessNonce + bytes([0,0]) + uInt16ToBytes(seccnt)
+
+def crypt_data(data, msgid, sessNonce, seccnt, key):
+    cipher = AES.new(key, AES.MODE_ECB)
+    nonce = getNonce(msgid, sessNonce, seccnt)
+    blkid = 1
+    o = cipher.encrypt(bytes([1]) + nonce + uInt16ToBytes(blkid))
+    return xor_bytes(data, o)
+
+def compute_auth(data, msgid, sessNonce, seccnt, key):
+    cipher = AES.new(key, AES.MODE_ECB)
+    nonce = getNonce(msgid, sessNonce, seccnt)
+    padded_data_length = 16
+    padded_data = data.ljust(padded_data_length, b'\0')
+    o = cipher.encrypt(bytes([9]) + nonce + uInt16ToBytes(len(data)))
+    #TODO: Implement for loop for chunked data
+    o = cipher.encrypt(xor_bytes(o, padded_data))
+    xv = cipher.encrypt(bytes([1]) + nonce + bytes([0,0]))
+    return xor_bytes(o[0:4], xv)
+
+def sendMsg(msgId, data):
+    global remote_nonce, key
+    getMsg(msgId, data, remote_nonce, key)
+
+def getMsg(msgId, data, remote_nonce, key):
+    seccnt = 1
+    cd = crypt_data(data, msgId, remote_nonce, seccnt, key)
+    bseccnt = uInt16ToBytes(seccnt)
+    authval = compute_auth(data, msgId, remote_nonce, seccnt, key)
+    seccnt += 1
+#    dumpNum(bytes([msgId]) + cd + bseccnt + authval)
+    payload = (bytes([128, msgId]) + cd + bseccnt + authval)
+#    print(payload.hex())
+    return payload
+    
+
+#print("TEST")
+#key = bytes.fromhex("3b74f06324ad365bc25916a01c547d1d")
+#local_nonce = "12345678"
+#remote_nonce = bytes([123,122,83,88,105,62,85,55])
+#remote_nonce = bytes.fromhex("d7 37 24 61 da f7 0f df")
+#
+#padcmd = bytes([1,0,0,0,0,0,0,0])
+#dumpNum(crypt_data(padcmd, 130, remote_nonce, 1, key))
+#sendMsg(135, padcmd)