Signed Bundle Verification via Catalog Segmentation

The solution segments the verification process into two distinct parts: (1) verification of the catalog file signature to ensure the catalog itself is authentic, and (2) verification of individual file hashes against the catalog to ensure files match their expected state. This segmentation allows the system to handle modified bundles by verifying only the remaining files against the original catalog, rather than requiring the entire original bundle structure to be present.

The catalog file serves as an intermediary between the bundle files and the verification process. By digitally signing the catalog file separately and storing it with the bundle, the system creates a trusted reference that mediates verification. The catalog contains hash values that act as intermediaries for comparing against actual files, allowing verification to proceed even when files are removed from the bundle, as long as the catalog signature remains valid.

The system performs preliminary action by calculating and storing hash values for each file in the catalog file before the bundle is distributed. This pre-computed hash catalog serves as a reference that enables future verification without requiring the original bundle structure. By preparing the catalog with all expected file hashes in advance, the system can later verify only the files that remain in modified bundles, allowing legitimate adaptations while maintaining security.

The solution extracts the verification mechanism from the bundle structure itself and places it in the separate catalog file. Instead of signing the entire bundle as a single unit where any modification breaks verification, the system extracts individual file hash references into the catalog, which is then signed. This extraction allows the bundle content to be modified (files removed) while the signed catalog remains valid as long as the remaining files match their expected hashes.