# Cryptographic Implementation Audit: Poindexter

**Date:** 2024-07-25

## 1. Executive Summary

A thorough audit of the Poindexter codebase was conducted to review its cryptographic implementations. The audit found **no instances of custom or third-party cryptographic code**. The project, in its current state, does not handle sensitive data requiring encryption, hashing, or secure random number generation.

Based on this analysis, the codebase is considered **out of scope** for a detailed cryptographic security review.

## 2. Audit Scope

The audit focused on the following areas as per the initial request:

- **Constant-time operations:** Searching for code where timing side-channels could leak sensitive information.
- **Key material handling:** Looking for storage, transmission, or use of cryptographic keys.
- **Random number generation:** Identifying the use of cryptographically secure (CSPRNG) vs. insecure random number generators.
- **Algorithm implementation correctness:** Verifying the implementation details of any cryptographic algorithms found.
- **Side-channel resistance:** General review for potential information leaks.

## 3. Findings

Our review of the entire Go codebase yielded the following observations:

### 3.1. No Cryptographic Implementations Found

The primary finding is that the Poindexter library does not contain any cryptographic functions. Its purpose is to provide sorting utilities and a k-d tree implementation, which do not inherently require cryptography.

### 3.2. Use of `math/rand`

The codebase makes use of the `math/rand` package in several test files:

- `kdtree_backend_parity_test.go`
- `fuzz_kdtree_test.go`
- `bench_kdtree_dual_test.go`

This usage is confined to generating random data for testing and benchmarking purposes (e.g., creating random points for the k-d tree). Since this data is not security-sensitive, the use of a non-cryptographically secure random number generator like `math/rand` is appropriate and poses no security risk.

### 3.3. DNS-related Mentions (`TLSA`)

The file `dns_tools.go` and its corresponding test file contain references to `TLSA` (TLS Authentication) DNS records. These references are limited to type definitions and descriptive strings. The codebase **does not implement** any part of the DANE protocol or the underlying cryptographic operations associated with TLSA records.

## 4. Recommendations

- **Continue Using Standard Libraries:** If cryptographic functionality is required in the future (e.g., for securing communications or data), it is strongly recommended to use Go's standard `crypto` library or other well-vetted, community-trusted cryptographic libraries.
- **Avoid Custom Implementations:** Do not implement custom cryptographic algorithms, as this is notoriously error-prone and can lead to severe security vulnerabilities.

## 5. Conclusion

The Poindexter library currently has no exposure to cryptographic implementation risks because it does not implement any cryptographic features. The existing code follows good practices by using non-secure random number generation only for non-security-critical applications. No corrective actions are required at this time.