Rule

freshness-bound-caller-time

Caller-supplied time reaches a security-sensitive effect without a canonical block-time freshness bound.

Release v0.1.1View Markdown

Specimen 09 of 96 · Audit-default ordinary rules

Severity
medium
Confidence
medium
Maturity
experimental
Selection
Audit default
Policy intent
not required
Release
v0.1.1
Engine facts used
resolved-model state-writes public-sinks

Selection and scope#

Selected by the default audit profile, so an ordinary scan runs it.

Shell
./.nightshade/node_modules/.bin/nightshade ./contracts --detectors freshness-bound-caller-time
./.nightshade/node_modules/.bin/nightshade detector show freshness-bound-caller-time

The first command runs only this rule; --detectors takes a comma-separated list. The second prints the rule's metadata from your installed version.

Severity is review priority. It does not express exploitability or impact. Confidence is detector metadata, not a probability. All built-in rules are experimental.

Compiler scope: the engine supports the pinned profiles 0.28.0, 0.29.0, 0.30.0, 0.31.1, 0.33.0-rc.2, 0.34.0, 0.35.0-rc.1 and 0.35.0, with ZKIR2 by default. Support for this rule can be narrower; the rule documentation below states any narrower scope.

Verified example#

Synthetic examplecompact-0.34.0-zkir2compiler-validated

The circuit accepts a caller-supplied time window without bounding it against chain time. From the proof run of the released CLI; the examples page also has the lookalike and the files.

Compactvulnerable.compactline 14 flagged
pragma language_version >= 0.23;
import CompactStandardLibrary;

export ledger startedAt: Uint<64>;
export ledger authenticated: Boolean;

constructor() {
  startedAt = 0;
  authenticated = false;
}

export circuit authenticate(expectedTimeWindow: Uint<64>): [] {
  assert(disclose(expectedTimeWindow >= startedAt), "window");
  startedAt = disclose(expectedTimeWindow);
  authenticated = true;
}
output.txtexit 1
$ nightshade vulnerable.compact --config config.json --compiler /path/to/compactc

MEDIUM — Caller time is not bound to protocol time [freshness-bound-caller-time]
vulnerable.compact:14:3
  14 |   startedAt = disclose(expectedTimeWindow);
     |   ^
authenticate accepts caller-supplied expectedTimeWindow and uses it in a state-changing or public effect without an asserted canonical block-time bound. A delayed, future-dated or stale proof may remain valid outside the intended freshness window. This source/effect review does not establish transaction ordering or exploitability.
Source: vulnerable.compact:12:29
Call path: authenticate
Remediation: Compare the caller value with block time using canonical blockTimeGte/blockTimeGt and blockTimeLte/blockTimeLt checks, or derive the deadline solely from a kernel-bound timestamp. Keep the bound on the same successful path as the state-changing effect.

Semantic profile: compact-0.34.0-zkir2.
Baseline analysis: complete; selected rules: complete.
Rule coverage: 1 selected rule(s); 0 with incomplete entries.
1 finding(s), 0 suppressed, 0 baseline; 2/2 entrypoint(s) completed; analysis complete. Compiler validation passed.

Corrected: Bound the caller's time with blockTimeGte before using it. Changed lines are marked.

Compactcorrected.compactrule quiet
pragma language_version >= 0.23;
import CompactStandardLibrary;

export ledger startedAt: Uint<64>;
export ledger authenticated: Boolean;

constructor() {
  startedAt = 0;
  authenticated = false;
}

export circuit authenticate(expectedTimeWindow: Uint<64>): [] {
  assert(blockTimeGte(disclose(expectedTimeWindow)), "future window");
  assert(disclose(expectedTimeWindow >= startedAt), "window");
  startedAt = disclose(expectedTimeWindow);
  authenticated = true;
}
corrected-output.txtexit 0
$ nightshade corrected.compact --config config.json --compiler /path/to/compactc

Semantic profile: compact-0.34.0-zkir2.
Baseline analysis: complete; selected rules: complete.
Rule coverage: 1 selected rule(s); 0 with incomplete entries.
0 finding(s), 0 suppressed, 0 baseline; 2/2 entrypoint(s) completed; analysis complete. Compiler validation passed.

The command line is shortened from the recorded run to what you would type; the output below it is verbatim, with absolute file paths shortened to the example folder. Long lines wrap. A quiet result shows that this rule stopped firing, not that the contract is secure.

Corpus checks#

Synthetic corpus checks for this rule in the 0.1.1 proof run. A check counts only with compiler acceptance and complete analysis.

Positive detectedCorrected quietLookalike quietOther negative quietIncomplete
12/1212/1212/120/00

No deviations were recorded for this rule.

These are behavior checks on synthetic fixtures, not a precision or recall estimate. See evaluation.

Rule documentation#

From docs/detectors/freshness-bound-caller-time.md at v0.1.1.

Availability: default source/effect review, no policy required. Severity/confidence: medium/medium.

This rule flags an exported circuit that uses caller-supplied time to enforce a freshness or deadline condition without binding that value to a kernel timestamp on the same successful path. A parameter name or Uint<64> type alone does not establish that a value is time.

Remediation: bind the supplied time to chain time in the same successful path, or derive the gate from a kernel-bound timestamp. Review both the timestamp-recording and delayed-action circuits.

A deliberate caller-selected time source can match and is not automatically a defect. The source/effect review does not infer time semantics from names or comments, follow every helper-mediated constraint, or prove a feasible stale-time execution.

Suppress a match#

If a match is intentional, suppress it on the line before with the exact rule ID and a reason of at least eight characters:

Compact
// nightshade-disable-next-line freshness-bound-caller-time -- Reason this match is intentional

Diagnostics cannot be suppressed, and an unmatched directive for a selected rule makes analysis incomplete. See configuration for fingerprint suppressions and baselines.

References#