diff options
Diffstat (limited to 'samloader/crypt.py')
| -rw-r--r-- | samloader/crypt.py | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/samloader/crypt.py b/samloader/crypt.py index ba7f91c..0b57c5a 100644 --- a/samloader/crypt.py +++ b/samloader/crypt.py @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-3.0+ # Copyright (C) 2020 nlscc -# Calculate keys and decrypt encrypted firmware packages. +""" Calculate keys and decrypt encrypted firmware packages. """ import hashlib import xml.etree.ElementTree as ET @@ -10,11 +10,12 @@ from clint.textui import progress from . import request from . import fusclient -from . import versionfetch +# PKCS#7 unpad unpad = lambda d: d[:-d[-1]] def getv4key(version, model, region): + """ Retrieve the AES key for V4 encryption. """ client = fusclient.FUSClient() req = request.binaryinform(version, model, region, client.nonce) resp = client.makereq("NF_DownloadBinaryInform.do", req) @@ -25,12 +26,15 @@ def getv4key(version, model, region): return hashlib.md5(deckey.encode()).digest() def getv2key(version, model, region): + """ Calculate the AES key for V2 (legacy) encryption. """ deckey = region + ":" + model + ":" + version return hashlib.md5(deckey.encode()).digest() def decrypt_progress(inf, outf, key, length): + """ Decrypt a stream of data while showing a progress bar. """ cipher = AES.new(key, AES.MODE_ECB) - assert length % 16 == 0 + if length % 16 != 0: + raise Exception("invalid input block size") chunks = length//4096+1 for i in progress.bar(range(chunks)): block = inf.read(4096) |