Proof Portal

Projects

jsonparser

ProbeLabs36 findings · 123 requirements
SYS-REQ-044SystemReview

When internal helper tokenEnd returns len(data) as a sentinel value indicating no delimiter was found, all callers of tokenEnd shall treat this sentinel as an end-of-input condition and shall not use it as an unchecked array index that could exceed the valid data range.

PriorityshallTypeguaranteeCategoryfunctionalComponentparserAssuranceEFindingsnone open

Specification

The requirement exactly as authored — its complete prose text and, where present, the formal FRETish sentence it compiles to.

Description

When internal helper tokenEnd returns len(data) as a sentinel value indicating no delimiter was found, all callers of tokenEnd shall treat this sentinel as an end-of-input condition and shall not use it as an unchecked array index that could exceed the valid data range.

FRETish formula
the parser shall always satisfy !tokenEnd_returns_len_data | caller_bounds_checks_tokenEnd_sentinel

Rationale & tags

Why this requirement exists, and how it is categorised.

The root cause of PR #280 was that tokenEnd returns len(data) as a sentinel, and Delete used data[endOffset+tokEnd] without checking whether endOffset+tokEnd >= len(data). This data constraint must be formalized.

sentineldata-constraintpr280

Verification & provenance

How this requirement was checked: the review trail, edit history, and the machine-analysis status terms (each ⓘ explains what it means).

Assurance levelE
Formalizationvalid
Realizabilityrealizable
Vacuitychecked_ok
Strategyfretish

Review

Status
approved
Reviewer
human:leonidbugaev
Reviewed
Apr 23, 2026, 00:00 UTC

History

Created
Apr 14, 2026, 18:00 UTC · agent:claude
Modified
Jul 26, 2026, 14:54 UTC · human:cli

Obligations

What this requirement must witness to be considered satisfied — the required evidence, and the tests that discharge each one.

1 obligation · 1 discharged

Browse the catalogue
Discharged
Worst case if violatedHigh

A caller of tokenEnd uses the returned len(data) sentinel as data[end] rather than treating it as EOF (e.g. value classification peeks data[tokenEnd(...)] for the next delimiter), panicking with index-out-of-range.

Discharging evidence1/1 required witnessed
  • nominalrequiredpresent
    Covered by 1 test

Formula evidence

The formal formula behind this requirement, the variables it is written over, and the tests that exercise it (each term is explained inline).

FRETish formula

the parser shall always satisfy !tokenEnd_returns_len_data | caller_bounds_checks_tokenEnd_sentinel

Variables

NameTypeDirectionDescription
tokenEnd_returns_len_dataTrue when the internal helper tokenEnd returns len(data) as a sentinel value indicating no delimiter was found in the remaining input.
caller_bounds_checks_tokenEnd_sentinelTrue when all callers of tokenEnd treat the len(data) sentinel as an end-of-input condition and do not use it as an unchecked array index.

Witnesses· 3 scenarios total

  • TestRemoval2_TokenEnd_NeverReturnsNegative
    dead_code_audit_test.go:108
  • TestRemoval2_TokenEnd_EmptyInput
    dead_code_audit_test.go:91
  • TestRemoval2_TokenEnd_NoDelimiter
    dead_code_audit_test.go:99
  • TestTokenEndSentinel
    deep_spec_test.go:110
  • TestMCDC_SYS_REQ_044_Row1_TriggerFalse
    mcdc_spec_witnesses_test.go:1515exercises 1 condition scenario
  • TestMCDC_SYS_REQ_044_Row2_InvariantViolation
    mcdc_spec_witnesses_test.go:1524exercises 1 condition scenario
  • TestMCDC_SYS_REQ_044_Row3_BoundsChecked
    mcdc_spec_witnesses_test.go:1540exercises 1 condition scenario
  • TestObligation_SYS_REQ_044
    obligation_evidence_test.go:392

Its place

This requirement shown inside its trace neighbourhood — the parents it satisfies, the code and tests attached to it, and its findings.

Loading graph…

Trace evidence

The concrete artifacts linked to this requirement — implementing code, verifying tests, documents, and the findings raised against it.

Impact

Blast radius — if you change this requirement, what else may need re-checking, and what it in turn depends on.

If you change this

Requirements
0
Files
1
Tests
4
At-risk contracts
0

Files to re-check (1)

  • parser.goparser.go

Tests to re-run (4)

  • dead_code_audit_test.godead_code_audit_test.go
  • deep_spec_test.godeep_spec_test.go
  • mcdc_spec_witnesses_test.gomcdc_spec_witnesses_test.go
  • obligation_evidence_test.goobligation_evidence_test.go

What this rests on

Discussions

Discuss this with the proof team. Nothing changes in your audit automatically — you open a request and a staff member records any outcome inside the thread.

Sign in to discuss this with the proof team.Sign in