Merge pull request #94 from chenxiaolong/zip_extra

Strip out 0xd935 extra field record in zip entries

avbroot/main.py

@@ -4,6 +4,7 @@ import copy
 import io
 import os
 import shutil
+import struct
 import tempfile
 import time
 import zipfile
@@ -150,6 +151,25 @@ def patch_ota_payload(f_in, open_more_f_in, f_out, file_size, boot_partition,
         )
 
 
+def strip_alignment_extra_field(extra):
+    offset = 0
+    new_extra = bytearray()
+
+    while offset < len(extra):
+        record_sig, record_len = \
+            struct.unpack('<HH', extra[offset:offset + 4])
+
+        next_offset = offset + 4 + record_len
+
+        # ALIGNMENT_ZIP_EXTRA_DATA_FIELD_HEADER_ID
+        if record_sig != 0xd935:
+            new_extra.extend(extra[offset:next_offset])
+
+        offset = next_offset
+
+    return new_extra
+
+
 def patch_ota_zip(f_zip_in, f_zip_out, boot_partition, root_patch,
                   clear_vbmeta_flags, privkey_avb, passphrase_avb, privkey_ota,
                   passphrase_ota, cert_ota):
@@ -195,16 +215,17 @@ def patch_ota_zip(f_zip_in, f_zip_out, boot_partition, root_patch,
 
         for info in infolist:
             out_info = copy.copy(info)
+            out_info.extra = strip_alignment_extra_field(out_info.extra)
 
             # Ignore because the plain-text legacy metadata file is regenerated
             # from the new metadata
             if info.filename == PATH_METADATA:
-                metadata_info = info
+                metadata_info = out_info
                 continue
 
             # The existing metadata is needed to generate a new signed zip
             elif info.filename == PATH_METADATA_PB:
-                metadata_pb_info = info
+                metadata_pb_info = out_info
 
                 with z_in.open(info, 'r') as f_in:
                     metadata_pb_raw = f_in.read()

tests/tests.yaml

@@ -135,8 +135,8 @@ device:
         full: 929f892fbd70699cf7f118a119aac1ae1b86351e1ada17715666fa4401e63472
         stripped: 6d9013c29aff5dc07ec549d844c5888089fe65f4a5c624bbd0afa04d1503ec8a
       patched:
-        full: 25f14582186e0f544480c6126b6b6ff0b6616023b796372d39af909300fb2e3a
-        stripped: 8c82dcc4427320fd8df4e1026c6d50ff92d5caf96e66a5c8f8b698f9fbe8806d
+        full: 1c4294f2faa711eacf4647025041e73d10488d7b9ff3a1a3142fe84b195cd9e0
+        stripped: c6abc228354ee6f4e338fce6860884c0aa6d4d2a72920e411c491ff52278702d
       avb_images:
         boot.img: ec703e143c24e7eb5b2eb96beb1d4342c1dd2179b12612d41430b1b55e7dec0f
         recovery.img: 2ff62bc52a5900eb170cc44df0f0ee8062ee6dcb48ecf1899ac556145161f53c