[HIGH] Missing Account Data Length Validation

[happybigmtn]

Summary

Account data is parsed without validating buffer length, causing crashes or garbage values on truncated/corrupted data.

Affected Files

• src/lib/program.ts:480-502 (parseCrapsGame)
• src/lib/program.ts:505-591 (parseCrapsPosition)

Problem Code

export function parseCrapsGame(data: Buffer): CrapsGame {
  let offset = 1;
  const epochId = data.readBigUInt64LE(offset); offset += 8;
  // ... no length check - will crash if data too short
}

Expected Sizes

• CrapsGame: 49 bytes minimum (1 + 8 + 1 + 1 + 6 + 8 + 8 + 8 + 8)
• CrapsPosition: 425 bytes minimum

Impact

• Severity: High
• Truncated account data causes crash
• Corrupted data returns garbage values
• Could display wrong game state, causing users to make bad bets

Proposed Fix

export function parseCrapsGame(data: Buffer): CrapsGame {
  const MIN_SIZE = 49;
  if (data.length < MIN_SIZE) {
    throw new Error(\`Invalid CrapsGame data: expected at least \${MIN_SIZE} bytes, got \${data.length}\`);
  }
  
  let offset = 1;
  // ... rest of parsing
}

export function parseCrapsPosition(data: Buffer): CrapsPosition {
  const MIN_SIZE = 425;
  if (data.length < MIN_SIZE) {
    throw new Error(\`Invalid CrapsPosition data: expected at least \${MIN_SIZE} bytes, got \${data.length}\`);
  }
  
  // ... rest of parsing
}

Labels

bug, data-integrity, high-priority, p1