## Summary
- Change the size header in embedded Mach-O and PE sections from `u32`
(4 bytes) to `u64` (8 bytes)
- Ensures the data payload starts at an 8-byte aligned offset, which is
required for the bytecode cache
## Test plan
- [x] Test standalone compilation on macOS
- [ ] Test standalone compilation on Windows
🤖 Generated with [Claude Code](https://claude.com/claude-code)
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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
## Summary
Implements authenticode signature stripping for Windows PE files when
using `bun build --compile`, ensuring that generated executables can be
properly signed with external tools after Bun embeds its data section.
## What Changed
### Core Implementation
- **Authenticode stripping**: Removes digital signatures from PE files
before adding the .bun section
- **Safe memory access**: Replaced all `@alignCast` operations with safe
unaligned access helpers to prevent crashes
- **Hardened PE parsing**: Added comprehensive bounds checking and
validation throughout
- **PE checksum recalculation**: Properly updates checksums after
modifications
### Key Features
- Always strips authenticode signatures when using `--compile` for
Windows (uses `.strip_always` mode)
- Validates PE file structure according to PE/COFF specification
- Handles overlapping memory regions safely during certificate removal
- Clears `IMAGE_DLLCHARACTERISTICS_FORCE_INTEGRITY` flag when stripping
signatures
- Ensures no unexpected overlay data remains after stripping
### Bug Fixes
- Fixed memory corruption bug using `copyBackwards` for overlapping
regions
- Fixed checksum calculation skipping 6 bytes instead of 4
- Added integer overflow protection in payload size calculations
- Fixed double alignment bug in `size_of_image` calculation
## Technical Details
The implementation follows the Windows PE/COFF specification and
includes:
- `StripMode` enum to control when signatures are stripped
(none/strip_if_signed/strip_always)
- Safe unaligned memory access helpers (`viewAtConst`, `viewAtMut`)
- Proper alignment helpers with overflow protection (`alignUpU32`,
`alignUpUsize`)
- Comprehensive error types for all failure cases
## Testing
- Passes all existing PE tests in
`test/regression/issue/pe-codesigning-integrity.test.ts`
- Compiles successfully with `bun run zig:check-windows`
- Properly integrated with StandaloneModuleGraph for Windows compilation
## Impact
This ensures Windows users can:
1. Use `bun build --compile` to create standalone executables
2. Sign the resulting executables with their own certificates
3. Distribute properly signed Windows binaries
Fixes issues where previously signed executables would have invalid
signatures after Bun added its embedded data.
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
