Verify the integrity of an audit log chain

Recomputes every entry hash and confirms each matches the stored value, and that each prev_hash matches its predecessor's entry_hash. Any discrepancy indicates tampering or corruption.

Usage

verify_log(log, verbose = TRUE)

Arguments

log

A regulog object or a character path to a .rlog file.

verbose

Logical. Print a summary. Defaults to TRUE.

Value

A list (invisibly) with components:

intact

Logical. TRUE if the chain is unbroken.

n_entries

Integer. Number of data entries verified (genesis excluded).

first_broken

Integer or NA. entry_id of the first invalid entry.

errors

Character vector of error descriptions.

Details

Verification algorithm

For each entry i (excluding the genesis record):

1. Reconstruct hash_input from the stored fields in canonical order.

2. Recompute digest(hash_input, algo = hash_algo).

3. Assert computed == entry$entry_hash (content integrity).

4. Assert entry$prev_hash == entry[i-1]$entry_hash (chain continuity).

Step 3 failure: the entry's content was modified after writing. Step 4 failure: entries were inserted, deleted, or reordered.

Examples

log <- regulog_init(app = "my-app", user = "jsmith")
log_action(log,
  action = "approved",
  object = "file.csv",
  reason = "Review complete"
)
#> regulog: logged action 'approved' on 'file.csv'
verify_log(log)
#> regulog: Log intact: 1 entry, chain unbroken
#> regulog: Log intact: 1 entry, chain unbroken