About This Example
This example demonstrates SSI's checksum verification feature for copied assets. The CSS file and fonts used by this page are all verified against checksums during the build process.
Verified Assets
The following assets are copied with checksum verification:
style.css— Stylesheet with custom fontsSelawik-Regular.woff— Regular weight fontSelawik-Bold.woff— Bold weight fontSelawik-LICENSE.txt— Font license
How It Works
The assets.xxh3 file contains xxHash3 checksums for each asset. During deployment:
- SSI copies each asset file to the output directory
- Computes the xxHash3 checksum of the deployed file
- Compares it against the expected checksum
- Detects any corruption, copy failures, or tampering
Smart Diagnostics
If a checksum mismatch occurs, SSI checks the source file to determine:
- Source changed: File was modified — update checksums if intentional
- Copy failed: Source is correct but deployed file differs — copy or tampering issue
- Outdated checksum: Source matches deployed but both differ from expected — regenerate checksums