Verification Protocol -- Aptos Move

How to prove a hypothesis is TRUE or FALSE using Move unit tests.

Evidence Source Tracking (MANDATORY)

CRITICAL: For EVERY piece of evidence used in verification, you MUST tag its source. Evidence from mocks or unverified external modules CANNOT support a REFUTED verdict.

Evidence Source Tags

Evidence Audit Table (REQUIRED in every verification output)

Before ANY verdict, fill this table:

### Evidence Audit
| Claim | Evidence Source | Tag | Valid for REFUTED? |
|-------|-----------------|-----|-------------------|
| "External module returns X" | Mock module | [MOCK] | NO |
| "State changes to Y" | protocol_module.move:123 | [CODE] | YES |
| "Coin transfer triggers Z" | Aptos Explorer source | [PROD-ONCHAIN] | YES |

Mock Rejection Rule

AUTOMATIC OVERRIDE: If ANY evidence supporting REFUTED has tag [MOCK] or [EXT-UNV]:

• CANNOT return REFUTED
• MUST return CONTESTED
• Triggers production verification

Example:

## Verdict: REFUTED -> CONTESTED (mock evidence override)

### Evidence Audit
| Claim | Source | Tag | Valid? |
|-------|--------|-----|--------|
| "Staking returns shares" | test_staking.move:45 | [MOCK] | NO |

**Override reason**: REFUTED verdict relies on mock behavior at test_staking.move:45.
Production module behavior is UNVERIFIED. Must verify against on-chain source.

Pre-Verification Understanding

Before writing ANY test code, you MUST answer:

Question 1: What is the EXACT bug?

NOT: "Something is inconsistent"
NOT: "State is wrong"
NOT: "Capability leak possible"

YES: "[Variable/resource] is [read/written/moved] at [location] but should be
      [read/written/moved] at [other location] because [specific reason]"

Question 2: What OBSERVABLE difference proves it?

NOT: "Values are different"
NOT: "State changed"

YES: "Before operation: [resource/value] = [expected value]
      After operation: [resource/value] = [actual value]
      Expected: [what it should be]"

Question 3: What is the EXACT assertion?

NOT: assert!(bug_exists, 0)
NOT: assert!(!is_secure, 0)

YES: assert!(actual_value == expected_value, ERROR_CODE)
 OR: assert!(before != after, ERROR_CODE)  // "value changed when it shouldn't"
 OR: assert!(error > threshold, ERROR_CODE)  // "error exceeds acceptable threshold"

If you cannot answer all three -> ASK FOR CLARIFICATION

Pre-PoC Feasibility Gates (MANDATORY)

Before writing test code, verify these two gates. If either FAILS, adjust the hypothesis.

Gate F1: Reachability

Trace a call path from a permissionless entry point to the vulnerable code.

• Entry point identified (public/external/entry function)
• Call path traced through intermediary functions
• All access checks on the path are passable by the attacker profile

If NO entry point reaches the vulnerable code → UNREACHABLE → FALSE_POSITIVE. If reachable only through a restricted path → document the restriction, adjust likelihood.

Gate F2: Math Bounds

Substitute real-world value domains into the expression that triggers the bug.

• Parameter domains identified (token decimals, max supply, TVL range, fee range, time bounds)
• Expression evaluated at worst-case feasible inputs
• Result crosses the bug threshold

If the bug requires values outside feasible domains → INFEASIBLE → FALSE_POSITIVE. If feasible only at extreme but realistic parameters → document the threshold, proceed with adjusted severity.

Both gates PASS → proceed to PoC. Either gate FAILS → document and stop.

Test File Template

See templates.md in this directory for all Move test file templates and Move-specific test patterns.

Interpreting Results

Test PASSES -> Bug CONFIRMED

The assertion that "proves the bug" succeeded.

• If assert!(after != before, 0) passes -> values ARE different (bug exists)
• If assert!(error > threshold, 0) passes -> error IS above threshold (bug exists)

Test FAILS -> Check Why

Common Aptos-Specific Test Issues

Iteration Protocol

Attempt 1: Direct implementation of test strategy from hypothesis

Attempt 2: Adjust parameters

• Different amounts (larger/smaller, boundary values)
• Different timing (advance more/fewer seconds)
• Different actors (swap attacker/victim roles)
• Different resource initialization order

Attempt 3: Re-examine assumptions

• Is setup correct? (all resources initialized, correct init order)
• Are preconditions met? (correct signer, sufficient balance, required state)
• Is the bug mechanism correctly understood?
• Are module dependencies correctly configured in Move.toml?

After 5 attempts:

• If still fails -> FALSE_POSITIVE with documented reasoning
• Explain why the hypothesis was wrong

Severity Determination

CRITICAL

• Direct fund theft possible (drain FungibleStore, mint unlimited tokens)
• Protocol insolvency (assets < liabilities)
• No special prerequisites needed (permissionless exploit)
• Attacker profits significantly
• Ref capability leak granting unrestricted mint/transfer/burn

HIGH

• Fund loss with some setup (specific state required)
• Broken core functionality (deposits, withdrawals, swaps non-functional)
• Significant value at risk
• Cumulative error compounds quickly
• Ref capability leak with limited but significant blast radius

MEDIUM

• Limited fund loss (bounded by rate limits, caps)
• Requires specific conditions (timing, state, multi-step)
• Edge cases with real impact
• Moderate value at risk
• Access control weakness that requires compromised friend module

LOW

• Negligible direct impact
• Extreme edge cases only
• Admin/owner controlled risk with compensating controls
• Informational with minor consequence

Output Format

CONFIRMED

## Verdict: CONFIRMED

### Evidence Audit
| Claim | Evidence Source | Tag | Valid for REFUTED? |
|-------|-----------------|-----|-------------------|

### Bug Mechanism Verified
{Explain what the test proves in 2-3 sentences}

### Test File
`tests/audit/test_hypothesis_N.move`

### Test Output

{Paste relevant aptos move test output}

### Key Evidence
| Metric | Value |
|--------|-------|
| Before | {value} |
| After | {value} |
| Expected | {value} |
| Difference | {calculation} |

### Severity: {LEVEL}
{Justification in 1-2 sentences}

### RAG Evidence
- **Attack Vectors Consulted**: [list bug classes queried]
- **Similar Exploits Found**: [count and brief descriptions]
- **PoC Template Used**: [yes/no, which template]
- **Historical Precedent**: [describe any matching historical vulnerabilities]

FALSE_POSITIVE

## Verdict: FALSE_POSITIVE

### Evidence Audit
| Claim | Evidence Source | Tag | Valid for REFUTED? |
|-------|-----------------|-----|-------------------|

### Attempts Made

**Attempt 1:**
- Approach: {description}
- Result: {what happened}
- Learning: {insight}

**Attempt 2:**
- Approach: {description}
- Result: {what happened}
- Learning: {insight}

**Attempt 3:**
- Approach: {description}
- Result: {what happened}
- Learning: {insight}

### Why It's Not a Bug
{Explain the actual behavior and why hypothesis was wrong in 2-3 sentences}

CONTESTED (CRITICAL)

## Verdict: CONTESTED

### Evidence Audit
| Claim | Evidence Source | Tag | Valid for REFUTED? |
|-------|-----------------|-----|-------------------|

### Evidence Status
| Checkpoint | Status | Details |
|------------|--------|---------|
| External behavior verified against PRODUCTION | NO | Used mock behavior as evidence |
| All callers checked | YES | Checked A, B, C |
| Ref access paths fully traced | NO | Friend module re-export not analyzed |
| Profit calculated with attacker holding | NO | Only analyzed donation loss |

### Why This Cannot Be REFUTED
{Explain what evidence is missing to definitively rule out the bug}

### Escalation Required
- [ ] Fetch production module source from Aptos Explorer for {external dep}
- [ ] Re-analyze with attacker holding shares/tokens
- [ ] Check additional caller paths: {list}
- [ ] Trace Ref access through friend modules: {list}

### Current Assessment
Likely: {TRUE_POSITIVE / FALSE_POSITIVE / UNKNOWN}
Confidence: {LOW / MEDIUM}

Insufficient Evidence (HALT CONDITIONS) -- CRITICAL

MANDATORY: You MUST check ALL boxes before returning REFUTED. If ANY checkbox is NO -> Return CONTESTED, not REFUTED.

Before marking REFUTED, check:

• External behavior verified against PRODUCTION (not mock)
  • Check Aptos Explorer for on-chain module source verification
  • If external module is marked 'UNVERIFIED' -> CANNOT use as evidence
  • If mock differs from production -> use PRODUCTION behavior
• Attack path checked on ALL callers (not just main path)
  • Enumerate all public fun and public entry fun that reach the vulnerable code
  • Check public(friend) fun callers via friend module analysis
• Ref capability paths fully traced
  • For Ref-related findings: trace every path from Ref creation to Ref usage
  • Check friend modules for transitive Ref access
  • Check if ExtendRef-derived signer enables unexpected access
• Profit calculated with attacker HOLDING tokens (not just donating)
  • "Attacker loses by donating" is NOT sufficient evidence
  • Check: what if attacker holds X% of shares BEFORE donating?
• Missing precondition documented
  • Document in structured format: precondition type + why it blocks
  • Types: STATE / ACCESS / TIMING / EXTERNAL / BALANCE
• Searched other findings for matching postconditions
  • Read {scratchpad}/findings_inventory.md for CONFIRMED/PARTIAL findings
  • Check if ANY finding creates the postcondition that would enable this attack
  • If match found -> CONTESTED, not REFUTED (chain analysis will combine)

Evidence That Does NOT Count

• "Mock shows X" -- mocks != production (CRITICAL: always verify against production)
• "Standard Coin module" -- may have custom transfer hooks via fungible_asset dispatch
• "Attacker loses by donating" -- may profit via shares held
• "Function is private/friend" -- friend module may expose it publicly
• "Requires admin signer" -- admin may be compromised or malicious
• "Attacker cannot acquire X" -- another finding may CREATE this condition
• "Ref is in private storage" -- friend module may provide access path

Anti-Downgrade Halt for VS/BLIND Findings (HARD RULE)

For findings from Validation Sweep ([VS-]) or Blind Spot Scanner ([BLIND-]): apply Rule 13's 5-question test BEFORE any downgrade. HALT: If test shows users harmed AND unavoidable AND undocumented -> you CANNOT return FALSE_POSITIVE. Minimum verdict: CONTESTED. Defense parity gaps (Module A has protection X, Module B lacks it for same action) are NEVER "by design" -> minimum severity: Medium, minimum verdict: CONTESTED. Violating this halt is a workflow error equivalent to using [MOCK] evidence for REFUTED.

Chain Analysis Integration

A finding is NEVER truly REFUTED until chain analysis completes.

If you mark a finding as REFUTED but document a missing precondition, the chain analyzer will search for other findings whose postconditions match your missing precondition. If found, the finding will be escalated to CONTESTED and combined into a chain hypothesis.

Example:

• Your finding: "Drain attack blocked because attacker cannot get TransferRef"
• Other finding: "Friend module exposes TransferRef via public function"
• Chain: Other finding enables your finding -> Combined HIGH severity

Advanced Protocol Reference: See advanced.md for RAG queries before PoC, exchange rate finding severity, design flaw escalation, bidirectional role analysis, chain hypothesis, and Aptos-specific verification considerations.