scripts: fix compute_authenticode_hash for unsigned PEs#440
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When the PE has no attached certificate the security data directory
fields VirtualAddress and Size are both 0. The previous unconditional
slicing:
pe_data[certificate_table_offset + 0x08 : 0] # -> empty
+ pe_data[0 + 0 :] # -> whole file re-appended
produced a wrong digest for unsigned images.
Add an explicit branch: when VirtualAddress == 0, hash only the bytes
that follow the 8-byte cert-dir data-directory entry, which is the
correct tail of an unsigned PE image.
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
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When the PE has no attached certificate the security data directory fields VirtualAddress and Size are both 0. The previous unconditional slicing:
produced a wrong digest for unsigned images.
Add an explicit branch: when VirtualAddress == 0, hash only the bytes that follow the 8-byte cert-dir data-directory entry, which is the correct tail of an unsigned PE image.
Description
When the PE has no attached certificate the security data directory
fields VirtualAddress and Size are both 0. The previous unconditional
slicing:
produced a wrong digest for unsigned images.
How This Was Tested
Generate Authenticode for an unsigned EFI binary and verify successful verification once enrolled in the DB.
Integration Instructions
N/A