44 lines
No EOL
1.2 KiB
Python
44 lines
No EOL
1.2 KiB
Python
import os
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import sys
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# Magic for the vbmeta image header
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AVB_MAGIC = b"AVB0"
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AVB_MAGIC_LEN = 4
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# Information about the verification flags
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FLAGS_OFFSET = 123
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FLAGS_TO_SET = b'\x03'
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if __name__ == "__main__":
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# if an argument is not provided
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if len(sys.argv) != 2:
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sys.exit("Usage: python ./" + os.path.basename(__file__) + " <vbmeta-image>")
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# try reading the file with read/write to make sure it exists
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FILE = sys.argv[1]
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try:
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fd = os.open(FILE, os.O_RDWR)
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except OSError:
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sys.exit("Error reading file: " + FILE + ". File not modified. Exiting...")
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# making sure it's a vbmeta image by reading the magic bytes at the start of the file
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magic = os.read(fd, AVB_MAGIC_LEN)
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if (magic != AVB_MAGIC):
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fd.close()
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sys.exit("Error: The provided image is not a valid vbmeta image. File not modified. Exiting...")
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# set the disable-verity and disable-verification flags at offset 123
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try:
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os.lseek(fd, FLAGS_OFFSET, os.SEEK_SET)
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os.write(fd, FLAGS_TO_SET)
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except OSError:
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fd.close()
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sys.exit("Error: Failed when patching the vbmeta image. Exiting...")
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# end of program
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os.close(fd)
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print("Patching successful.") |