Attempt to decrypt account URL as LastPass has started encrypting this field

lastpass/parser.py

@@ -50,7 +50,11 @@ def parse_ACCT(chunk, encryption_key):
     id = read_item(io)
     name = decode_aes256_plain_auto(read_item(io), encryption_key)
     group = decode_aes256_plain_auto(read_item(io), encryption_key)
-    url = decode_hex(read_item(io))
+    url_encoded = read_item(io)
+    try:
+        url = decode_aes256_plain_auto(url_encoded, encryption_key)
+    except ValueError:
+        url = decode_hex(url_encoded)
     notes = decode_aes256_plain_auto(read_item(io), encryption_key)
     skip_item(io, 2)
     username = decode_aes256_plain_auto(read_item(io), encryption_key)
@@ -72,10 +76,13 @@ def parse_ACCT(chunk, encryption_key):
 
 def parse_PRIK(chunk, encryption_key):
     """Parse PRIK chunk which contains private RSA key"""
-    decrypted = decode_aes256('cbc',
-                              encryption_key[:16],
-                              decode_hex(chunk.payload),
-                              encryption_key)
+    if chunk.payload[:1] in (b'!', '!'):
+        decrypted = decode_aes256_base64_auto(chunk.payload, encryption_key)
+    else:
+        decrypted = decode_aes256('cbc',
+                                  encryption_key[:16],
+                                  decode_hex(chunk.payload),
+                                  encryption_key)
 
     hex_key = re.match(br'^LastPassPrivateKey<(?P<hex_key>.*)>LastPassPrivateKey$', decrypted).group('hex_key')
     rsa_key = RSA.importKey(decode_hex(hex_key))

tests/test_parser.py

@@ -1,8 +1,10 @@
 # coding: utf-8
-from base64 import b64decode
+from base64 import b64decode, b64encode
 import codecs
+import struct
 import unittest
 from io import BytesIO
+from Crypto.Cipher import AES
 from lastpass.blob import Blob
 from lastpass.chunk import Chunk
 from lastpass import parser
@@ -177,6 +179,33 @@ def test_parse_PRIK_parses_private_key(self):
                                              "62999647203566877832873138065626190040996517274" +
                                              "418161068665712298519808863"))
 
+    def test_parse_PRIK_parses_v2_private_key(self):
+        legacy_ciphertext = parser.decode_hex(self.encoded_rsa_key)
+        plaintext = parser.decode_aes256(
+            'cbc',
+            self.rsa_key_encryption_key[:16],
+            legacy_ciphertext,
+            self.rsa_key_encryption_key)
+        iv = b'\0' * AES.block_size
+        padding_length = AES.block_size - len(plaintext) % AES.block_size
+        padded = plaintext + struct.pack('B', padding_length) * padding_length
+        ciphertext = AES.new(
+            self.rsa_key_encryption_key,
+            AES.MODE_CBC,
+            iv).encrypt(padded)
+        encoded = b'!' + b64encode(iv) + b'|' + b64encode(ciphertext)
+
+        legacy_key = parser.parse_PRIK(
+            Chunk(b'PRIK', self.encoded_rsa_key),
+            self.rsa_key_encryption_key)
+        v2_key = parser.parse_PRIK(
+            Chunk(b'PRIK', encoded),
+            self.rsa_key_encryption_key)
+
+        self.assertEqual(v2_key.n, legacy_key.n)
+        self.assertEqual(v2_key.e, legacy_key.e)
+        self.assertEqual(v2_key.d, legacy_key.d)
+
     def test_parse_secure_note_server_returns_parsed_values(self):
         type = b'type'
         url = b'url'