contrib/dell_extract_hdr: `UnicodeDecodeError: 'utf-8' codec can't decode byte 0x90 in position 2: invalid start byte`

[paulmenzel]

Trying to extract HDR from the Dell OptiPlex 5055 1.1.25 firmware update file fails with the error below:

$ ~/src/uefi-firmware-parser/scripts/contrib/dell_extract_hdr.py ~/OptiPlex\ 5055\ Ryzen\ CPU_1.1.25.exe
Traceback (most recent call last):
  File "/home/joey/src/uefi-firmware-parser/scripts/contrib/dell_extract_hdr.py", line 38, in <module>
    data = fh.read()
  File "/pkg/python-3.8.9-1/lib/python3.8/codecs.py", line 322, in decode
    (result, consumed) = self._buffer_decode(data, self.errors, final)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x90 in position 2: invalid start byte

[paulmenzel]

$ binwalk ~/OptiPlex\ 5055\ Ryzen\ CPU_1.1.25.exe

DECIMAL       HEXADECIMAL     DESCRIPTION
--------------------------------------------------------------------------------
0             0x0             Microsoft executable, portable (PE)
266024        0x40F28         CRC32 polynomial table, little endian
270120        0x41F28         CRC32 polynomial table, big endian
274399        0x42FDF         Copyright string: "Copyright 1995-2010 Mark Adler "
304854        0x4A6D6         Copyright string: "Copyright 2009-2019"
305342        0x4A8BE         Copyright string: "Copyright 2009-2019"
502800        0x7AC10         Zlib compressed data, default compression
6502200       0x633738        Object signature in DER format (PKCS header length: 4, sequence length: 8662
6502341       0x6337C5        Certificate in DER format (x509 v3), header length: 4, sequence length: 1277
6503622       0x633CC6        Certificate in DER format (x509 v3), header length: 4, sequence length: 1309
6505590       0x634476        Object signature in DER format (PKCS header length: 4, sequence length: 5272
6505751       0x634517        Certificate in DER format (x509 v3), header length: 4, sequence length: 1066
6506821       0x634945        Certificate in DER format (x509 v3), header length: 4, sequence length: 1299
6508124       0x634E5C        Certificate in DER format (x509 v3), header length: 4, sequence length: 1548

[paulmenzel]

After binwalk --extract ~/OptiPlex\ 5055\ Ryzen\ CPU_1.1.25.exe, the directory _OptiPlex 5055 Ryzen CPU_1.1.25.exe.extracted contains the (uncompressed) 16784441 bytes (≈ 16 MB) file 7AC10, which UEFITool is able to open.