1 files changed, 124 insertions, 0 deletions
diff --git a/module/plugins/hoster/MegaNz.py b/module/plugins/hoster/MegaNz.py
new file mode 100644
index 000000000..5041fb868
--- /dev/null
+++ b/module/plugins/hoster/MegaNz.py
@@ -0,0 +1,124 @@
+# -*- coding: utf-8 -*-
+
+import re
+import random
+from array import array
+from os import remove
+from base64 import standard_b64decode
+
+from Crypto.Cipher import AES
+from Crypto.Util import Counter
+
+from module.common.json_layer import json
+from module.plugins.Hoster import Hoster
+
+#def getInfo(urls):
+#    pass
+
+class MegaNz(Hoster):
+    __name__ = "MegaNz"
+    __type__ = "hoster"
+    __pattern__ = r"https?://([a-z0-9]+\.)?mega\.co\.nz/#!([a-zA-Z0-9!_\-]+)"
+    __version__ = "0.1"
+    __description__ = """mega.co.nz hoster plugin"""
+    __author_name__ = ("RaNaN", )
+    __author_mail__ = ("ranan@pyload.org", )
+
+    API_URL = "https://g.api.mega.co.nz/cs?id=%d"
+    FILE_PREFIX = ".crypted"
+
+    def b64_decode(self, data):
+        return standard_b64decode(data.replace("-", "+").replace("_", "/")+ "=")
+
+    def getCipherKey(self, key):
+        """ Construct the cipher key from the given data """
+        a = array("I", key)
+        key_array = array("I", [a[0] ^ a[4], a[1] ^a[5], a[2] ^ a[6], a[3] ^a[7]])
+        return key_array
+
+    def callApi(self, **kwargs):
+        """ Dispatch a call to the api, see https://mega.co.nz/#developers """
+        # generate a session id, no idea where to obtain elsewhere
+        uid = random.randint(10 << 9, 10 ** 10)
+
+        resp = self.load(self.API_URL % uid, post=json.dumps([kwargs]))
+        self.logDebug("Api Response: " + resp)
+        return json.loads(resp)
+
+    def decryptAttr(self, data, key):
+
+        cbc = AES.new(self.getCipherKey(key), AES.MODE_CBC, "\0" * 16)
+        attr = cbc.decrypt(self.b64_decode(data))
+        self.logDebug("Decrypted Attr: " + attr)
+        if not attr.startswith("MEGA"):
+            self.fail(_("Decryption failed"))
+
+        # Data is padded, 0-bytes must be stripped
+        return json.loads(attr.replace("MEGA", "").strip("\0").strip())
+
+    def decryptFile(self, key):
+        """  Decrypts the file at lastDownload` """
+
+        # upper 64 bit of counter start
+        n = key[16:24]
+
+        # convert counter to long and shift bytes
+        ctr = Counter.new(128, initial_value=long(n.encode("hex"),16) << 64)
+        cipher = AES.new(self.getCipherKey(key), AES.MODE_CTR, counter=ctr)
+
+        self.pyfile.setStatus("decrypting")
+        f = open(self.lastDownload, "rb")
+        df = open(self.lastDownload.rstrip(self.FILE_PREFIX), "wb")
+
+        # TODO: calculate CBC-MAC for checksum
+
+        size = 2 ** 15 # buffer size, 32k
+        while True:
+            buf = f.read(size)
+            if not buf: break
+
+            df.write(cipher.decrypt(buf))
+
+        f.close()
+        df.close()
+        remove(self.lastDownload)
+
+    def process(self, pyfile):
+
+        key = None
+
+        # match is guaranteed because plugin was chosen to handle url
+        node = re.search(self.__pattern__, pyfile.url).group(2)
+        if "!" in node:
+            node, key = node.split("!")
+
+        self.logDebug("File id: %s | Key: %s" % (node, key))
+
+        if not key:
+            self.fail(_("No file key provided in the URL"))
+
+        # g is for requesting a download url
+        # this is like the calls in the mega js app, documentation is very bad
+        dl = self.callApi(a="g", g=1, p=node, ssl=1)[0]
+
+        if "e" in dl:
+            e = dl["e"]
+            # ETEMPUNAVAIL (-18): Resource temporarily not available, please try again later
+            if e == -18:
+                self.retry()
+            else:
+                self.fail(_("Error code:") + e)
+
+        # TODO: map other error codes, e.g
+        # EACCESS (-11): Access violation (e.g., trying to write to a read-only share)
+
+        key = self.b64_decode(key)
+        attr = self.decryptAttr(dl["at"], key)
+
+        pyfile.name = attr["n"] + self.FILE_PREFIX
+
+        self.download(dl["g"])
+        self.decryptFile(key)
+
+        # Everything is finished and final name can be set
+        pyfile.name = attr["n"]