Eva is designed as a safety-conscious command-line intelligence assistant. Security and data privacy are core architectural requirements, not optional add-ons.

Eva automatically sanitizes text to redact sensitive credentials before data is sent over the network to AI providers or saved to local disk (audit logs, terminal replays, workspace session notes, and history).

1. Regex Pattern Matching:

   • OpenAI / Anthropic / OpenRouter Keys: sk-[A-Za-z0-9_-]{20,}
   • GitHub Access Tokens: ghp_, gho_, ghu_, ghs_, ghr_
   • GitLab Personal Access Tokens: glpat-
   • AWS Access Key IDs: AKIA[0-9A-Z]{16}
   • Slack Tokens: xoxb-, xoxp-, xoxr-, xoxa-, xoxs-
   • Eva Provider Environment Variables: EVA_<PROVIDER>_API_KEY=...
   • HTTP Auth Headers: Bearer ..., Basic ...
   • Generic Secret Assignments: api_key, secret, password, auth_token, access_token
   • PEM Private Key Blocks: -----BEGIN [RSA|EC|DSA|OPENSSH] PRIVATE KEY-----

2. Shannon Entropy Analysis:

   • Evaluates randomness for all strings $\ge 16$ characters using Shannon entropy: $$H(S) = -\sum_{i} p(x_i) \log_2 p(x_i)$$
   • Tokens exceeding the entropy threshold ($H(S) > 3.5$ bits/char) are automatically redacted as [REDACTED_HIGH_ENTROPY].

All executed, blocked, or declined commands generated via eva work or eva workflow are recorded in an append-only, tamper-evident audit log at ~/.config/eva/command_audit.jsonl.

Each log record includes a sequence number seq, the previous record's hash prev_hash, and a SHA-256 signature hash: $$\text{hash}i = \text{SHA-256}(\text{prev_hash}{i-1} \mathbin{:} \text{canonical_json}(\text{record}_i))$$

• The first record in the chain uses $\text{prev_hash}_0 = 0^{64}$.
• If an attacker modifies, deletes, or inserts an audit log record, verify_audit_chain() detects the cryptographic break and reports the exact sequence number where tampering occurred.

Eva supports running potentially risky shell commands inside a restricted subprocess sandbox.

• Environment Stripping: Only explicit safe environment variables (PATH, HOME, USER, LANG, TERM, TMPDIR, PWD) are passed into the process.
• Input Isolation: stdin is attached to DEVNULL to prevent unauthorized interactive sub-shells.
• Timeout Enforcement: Standard 30-second execution timeout; processes failing to complete are terminated with SIGKILL.
• Opt-In Configuration: Disabled by default to preserve normal user environment behavior. Enable in ~/.config/eva/config.toml:

  [general]
  sandbox_risky_commands = true

Eva includes zero default remote tracking or analytics.

• Disabled by Default: telemetry_enabled = false.
• Strict Data Scope: When explicitly enabled by the user, Eva collects only:
  • Provider response latency (seconds)
  • Provider success / failure status
  • Error class names (e.g. RateLimitError, AuthError)
• Strict Exclusion: Prompt text, code snippets, file paths, shell commands, and git diffs are NEVER collected or transmitted.

If you discover a security vulnerability in Eva, please do not open a public GitHub issue. Send a report to rootagi@duck.com or follow responsible disclosure practices.