ukify: Weaken file alignment assertions

Older versions of the stub are not aligned to the PE file alignment
size. If we remove the assertions, the UKI still boots without issues,
so let's drop the assertions and print a message about it instead.

diff --git a/src/ukify/ukify.py b/src/ukify/ukify.py
index 2cdfc01ad4f80c061385b8b3b7d67e2a61f610e5..99128014d93e14f5b8af27c318e8678e7b59d540 100755 (executable)
--- a/src/ukify/ukify.py
+++ b/src/ukify/ukify.py
@@ -449,7 +449,7 @@ class PeError(Exception):
 
 def pe_add_sections(uki: UKI, output: str):
     pe = pefile.PE(uki.executable, fast_load=True)
-    assert len(pe.__data__) % pe.OPTIONAL_HEADER.FileAlignment == 0
+    assert pe.FILE_HEADER.PointerToSymbolTable != 0 or len(pe.__data__) % pe.OPTIONAL_HEADER.FileAlignment == 0
 
     warnings = pe.get_warnings()
     if warnings:
@@ -460,6 +460,12 @@ def pe_add_sections(uki: UKI, output: str):
         # We could strip the signatures, but why would anyone sign the stub?
         raise PeError(f'Stub image is signed, refusing.')
 
+    # If the executable has not been stripped, it might not be aligned to a multiple of the file alignment so
+    # let's make sure it is by padding it.
+    if pe.FILE_HEADER.PointerToSymbolTable != 0:
+        padlen = round_up(len(pe.__data__), pe.OPTIONAL_HEADER.FileAlignment) - len(pe.__data__)
+        pe.__data__ = pe.__data__[:] + padlen * b'\0'
+
     for section in uki.sections:
         new_section = pefile.SectionStructure(pe.__IMAGE_SECTION_HEADER_format__, pe=pe)
         new_section.__unpack__(b'\0' * new_section.sizeof())