fix: fix reserved bytes len and md5 len in compressed image header

tools/cmake_utilities/CHANGELOG.md

@@ -1,3 +1,10 @@
+## v0.4.2 - 2023-03-20
+
+### Bugfix:
+
+* gen_compressed_ota: Fix the number of bytes reserved in the v3 compressed image header
+* gen_compressed_ota: Fix definition of MD5 length in compressed image header for different versions.
+
 ## v0.4.1 - 2023-03-15
 
 * relinker: add option to use customized configuration files

tools/cmake_utilities/idf_component.yml

@@ -1,4 +1,4 @@
-version: "0.4.1"
+version: "0.4.2"
 description: A collection of useful cmake utilities
 url: https://github.com/espressif/esp-iot-solution/tree/master/tools/cmake_utilities
 issues: https://github.com/espressif/esp-iot-solution/issues

tools/cmake_utilities/scripts/gen_custom_ota.py

@@ -178,13 +178,15 @@ def main():
             bin_data += struct.pack('32s', firmware_ver.encode())
         else:
             # Reserved
-            bin_data += struct.pack('<I', 0)
-            bin_data += struct.pack('<I', 0)
+            bin_data += struct.pack('10s', b'0')
         # The length of the compressed data
         bin_data += struct.pack('<I', f_len)
         print('compressed data len: {}'.format(f_len))
         # The MD5 for the compressed data
-        bin_data += struct.pack('16s', hashlib.md5(data).digest())
+        if (header_version[header_ver] < 3):
+            bin_data += struct.pack('32s', hashlib.md5(data).digest())
+        else:
+            bin_data += struct.pack('16s', hashlib.md5(data).digest())
         # The CRC32 for the header
         bin_data += struct.pack('<I', binascii.crc32(bin_data, 0x0))