pamoja-audit

A tamper-evident, hash-chained log; altering, reordering, or dropping a record breaks verification. One capability of pamoja, one memory-safe Rust core with bindings for TypeScript, Python, and C#.

Install

pip install pamoja-audit

from pamoja import audit

This pulls in pamoja-native, the compiled engine, and pamoja-security. pip install pamoja is the whole framework in one package.

Example

The script the test suite runs, spliced here as it ran.

From bindings/python/guides/audit.py:

from pamoja.audit import AuditEntry, AuditLog, verify_chain
from pamoja.core import PamojaError
from pamoja.security import DeviceIdentity

# The controller signs its own log with a provisioned seed and an auditor holds only the
# public half, so a log can be checked anywhere without the device present.
keeper = DeviceIdentity.from_seed(bytes([7]) * 32)
auditor = keeper.public_key

log = AuditLog(keeper)
lit = log.append(b"burner=on")
stopped = log.append(b"burner=off")
print(f"recorded  {lit.index} then {stopped.index}")

# Each record hashes its own index, the digest of the record before it, and what it
# carries, so the chain fixes the order as well as the contents.
print(f"chained   {stopped.previous == lit.digest}")
verify_chain(auditor, [lit, stopped])
print("verified  the whole log is authentic and in order")

# Editing a stored record changes the digest its signature covers.
edited = bytearray(stopped.to_bytes())
edited[-1] ^= 0xFF
tampered = AuditEntry.from_bytes(bytes(edited))
try:
    verify_chain(auditor, [lit, tampered])
    print("an edited record verified, which should never happen")
except PamojaError as error:
    print(f"edited    caught: {error}")

# Dropping the first record leaves the survivor chained to a link that is no longer there,
# so a shortened log is caught as readily as an edited one.
try:
    verify_chain(auditor, [stopped])
    print("a shortened log verified, which should never happen")
except PamojaError as error:
    print(f"shortened caught: {error}")

The same capability in every language

Documentation

• pamoja.audit reference, every class and function in this module.
• The Audit log guide, with the same example in Rust, TypeScript, and C#.
• Every capability, and the install page.

License

MIT