f1aee66f92
This is useful whenever you want to diagnose the current state of UEFI variables, to assert that bootloaders or boot programs (systemd-stub) did their job correctly and set their variables accordingly. In the future, it can enable inspecting SecureBoot keys also.
32 lines
1.0 KiB
Python
32 lines
1.0 KiB
Python
from enum import IntEnum
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class EfiVariableAttributes(IntEnum):
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NonVolatile = 0x01
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BootServiceAccess = 0x02
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RuntimeAccess = 0x04
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HardwareErrorRecord = 0x08
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AuthenticatedWriteAccess = 0x10
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TimeBasedAuthenticatedWriteAccess = 0x20
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AppendWrite = 0x40
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EnhancedAuthenticatedAccess = 0x80
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class EfiVariable:
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"""
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An EFI variable represented by its attributes and raw value in bytes.
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Generally, the value is not encoded in UTF-8, but UCS-2 or UTF-16-LE.
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"""
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attributes: EfiVariableAttributes
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value: bytes
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def __init__(self, value: bytes, attributes: bytes):
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self.value = value
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self.attributes = EfiVariableAttributes(attributes)
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def value_as_null_terminated_string(self, encoding: str = 'utf-16-le'):
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"""
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Most often, variables are encoded with a null-terminated \x00.
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This function gives you the string in a default encoding of UTF-16-LE
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stripped of the null terminator.
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"""
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return self.value.decode(encoding).rstrip('\x00')
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