declared-secret-publication

Availability: policy-required; selected by default, but needs policies.secrets. Severity high, confidence medium.

Reports a policy-selected witness or entry parameter influencing a real public sink in a form not approved by allowedForms. This includes implicit control dependencies. disclose does not remove the source dependency; exported returns cross the application-output boundary, while ledger sinks publish ledger data. Without sinkKinds, the policy covers every public sink kind. An optional nonempty selection scopes it to ledger-write, exported-return, ledger-operation, or event; allowedForms still applies within that selection.

Example and review scenario#

The compiler-qualified owned fixture forwards secret() through a helper to a ledger write. Its policy is:

{ "secrets": [{ "witness": "secret" }] }

Place this object under policies in the configuration. The correction publishes a constant independent of the witness. Review this finding when an application's privacy contract says a witness or parameter must not affect public output.

Recommendation: remove the public dependency, including private-controlled effects, or explicitly approve a transformation after reviewing the disclosure requirements. Entry-parameter policies use circuit and parameter selectors.

For an exported-return policy, select exported-return in sinkKinds. This scopes the policy to application outputs while leaving other sink kinds outside that policy selection; it does not establish that those operations hide a source or that the entire contract is secure.

False positives and limitations#

An outdated or overbroad secrecy policy can flag intentional disclosures. Forms raw, derived, hash and commitment classify tracked transformations; they are not hiding proofs. Broadly approving derived can conceal implicit flows. No secrecy intent is inferred without policy, and abstract successful paths do not prove concrete feasibility. Incomplete analysis cannot establish absence of leaks.

Source examples#

These short regression examples are included here for installed-package readers. Rule-specific policy requirements and limits above still apply.

Example 1#

Fixture (source: tests/corpus/vulnerable/declared-secret.compact).

pragma language_version >= 0.26.0;
export ledger published: Field;
witness secret(): Field;
circuit forward(value: Field): Field { return value; }
export circuit publish(): [] {
  published = disclose(forward(secret()));
}

Example 2#

Correction (source: tests/corpus/safe/declared-secret.compact).

pragma language_version >= 0.26.0;
export ledger published: Field;
witness secret(): Field;
circuit forward(value: Field): Field { return value; }
export circuit publish(): [] {
  const unused = secret();
  published = 0 as Field;
}