Verification Protocol

How to prove a hypothesis is TRUE or FALSE using Foundry 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 contracts 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 returns X" | Mock contract | [MOCK] | NO |
| "State changes to Y" | Protocol.sol:123 | [CODE] | YES |
| "Transfer triggers Z" | Etherscan source | [PROD] | 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 (Step 4a.5)

Example:

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

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

**Override reason**: REFUTED verdict relies on mock behavior at StakingMock.sol:45.
Production contract behavior is UNVERIFIED. Must fetch production 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: "Reentrancy possible"

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

Question 2: What OBSERVABLE difference proves it?

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

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

Question 3: What is the EXACT assertion?

NOT: assertTrue(bugExists)
NOT: assertFalse(isSecure)

YES: assertEq(actualValue, expectedValue, "description of what's wrong")
 OR: assertNotEq(before, after, "value changed when it shouldn't")
 OR: assertGt(error, threshold, "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

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "forge-std/Test.sol";
import "forge-std/console.sol";

/**
 * @title Test_H{N}: {Title}
 *
 * BUG: {2 sentence description}
 * EXPECTED: {what should happen}
 * ACTUAL: {what does happen}
 */
contract Test_H{N} is Test {

    // === CONTRACTS ===
    // Declare target contract and any dependencies

    // === ACTORS ===
    address attacker = makeAddr("attacker");
    address victim = makeAddr("victim");
    address owner = makeAddr("owner");

    // === SETUP ===
    function setUp() public {
        // Deploy contracts
        // Set initial state
        // Fund actors if needed
    }

    // === TEST: Direct bug demonstration ===
    function test_H{N}_bug_demonstration() public {
        // 1. RECORD BEFORE
        console.log("=== BEFORE ===");
        uint256 valueBefore = target.criticalValue();
        console.log("Critical value:", valueBefore);

        // 2. ACTION
        console.log("=== ACTION ===");
        // Perform the operation that triggers the bug

        // 3. RECORD AFTER
        console.log("=== AFTER ===");
        uint256 valueAfter = target.criticalValue();
        console.log("Critical value:", valueAfter);

        // 4. PROVE BUG
        console.log("=== VERIFICATION ===");
        // THE ASSERTION THAT PROVES THE BUG
        // Design this so it PASSES when the bug EXISTS
    }

    // === TEST: Impact demonstration (optional) ===
    function test_H{N}_impact() public {
        // Show cumulative impact or attacker profit
    }
}

Interpreting Results

Test PASSES -> Bug CONFIRMED

The assertion that "proves the bug" succeeded.

• If assertNotEq(after, before) passes -> values ARE different (bug exists)
• If assertGt(error, threshold) passes -> error IS above threshold (bug exists)

Test FAILS -> Check Why

Iteration Protocol

Attempt 1: Direct implementation of test strategy from hypothesis

Attempt 2: Adjust parameters

• Different amounts (larger/smaller)
• Different timing (more/fewer blocks)
• Different actors

Attempt 3: Re-examine assumptions

• Is setup correct?
• Are preconditions met?
• Is the bug mechanism correctly understood?

After 5 attempts:

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

Severity Determination

CRITICAL

• Direct fund theft possible
• Protocol insolvency
• No special prerequisites needed
• Attacker profits significantly

HIGH

• Fund loss with some setup
• Broken core functionality
• Significant value at risk
• Cumulative error compounds quickly

MEDIUM

• Limited fund loss
• Requires specific conditions
• Edge cases with real impact
• Moderate value at risk

LOW

• Negligible direct impact
• Extreme edge cases only
• Owner/admin controlled risk
• Informational with minor consequence

Output Format

CONFIRMED

## Verdict: CONFIRMED

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

### Test File
`test/audit/Test_H{N}.t.sol`

### Test Output

{Paste relevant forge test output}

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

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

FALSE_POSITIVE

## Verdict: FALSE_POSITIVE

### 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 (NEW in v5 -- CRITICAL)

## Verdict: CONTESTED

### Evidence Status
| Checkpoint | Status | Details |
|------------|--------|---------|
| External behavior verified against PRODUCTION | NO | Used mock behavior as evidence |
| All callers checked | YES | Checked A, B, C |
| 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 contract source for {external dep}
- [ ] Re-analyze with attacker holding shares
- [ ] Check additional caller paths: {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)
  • Read {scratchpad}/external_production_behavior.md
  • If external dep 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)
  • Use mcp__slither-analyzer__get_function_callers() to enumerate
• 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 ERC20" -- may have transfer hooks, side effects
• "Attacker loses by donating" -- may profit via shares held
• "Function is internal" -- may be called by public function
• "Requires admin" -- admin may be compromised or malicious
• "Attacker cannot acquire X" -- another finding may CREATE this condition

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 (Contract A has protection X, Contract 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 (Step 6b) 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: "Donation attack blocked because attacker cannot hold receipt tokens"
• Other finding: "External protocol interaction returns transferable receipt tokens"
• 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, RAG confidence override, chain hypothesis protection, fork testing, and Foundry PoC methodology.