Security Checklists

Comprehensive validation checklists for Solana program security reviews.

Account Validation Checklist

For every account in every instruction:

Signer validation: Uses Signer<'info> or is_signer check when needed
Owner validation: Uses #[account(owner = ...)] or manual owner check
Writable checks: Properly marked mut when account data will be modified
Account initialization: Checks if account is initialized before use
PDA validation: Validates seeds and uses canonical bump
Discriminator check: For AccountLoader, validates account type
Account relationships: Uses has_one for related accounts

// Complete account validation example
#[derive(Accounts)]
pub struct SecureInstruction<'info> {
    #[account(
        mut,
        has_one = authority,  // Relationship validation
        seeds = [b"vault", authority.key().as_ref()],
        bump,  // Canonical bump
    )]
    pub vault: Account<'info, Vault>,

    pub authority: Signer<'info>,  // Signer required

    #[account(
        mut,
        constraint = token_account.owner == authority.key(),  // Custom validation
    )]
    pub token_account: Account<'info, TokenAccount>,

    pub token_program: Program<'info, Token>,  // Program validation
}

Arithmetic Safety Checklist

For all mathematical operations:

Addition: Uses checked_add() instead of +
Subtraction: Uses checked_sub() instead of -
Multiplication: Uses checked_mul() instead of *
Division: Uses checked_div() instead of /
Division by zero: Validates divisor is non-zero
Precision loss: Uses try_floor_u64() instead of try_round_u64() to prevent arbitrage
Avoid saturating: Does not use saturating_* methods (they hide errors)
Proper error handling: All arithmetic wrapped in ok_or(error)?

// Secure arithmetic examples
let total = balance
    .checked_add(amount)
    .ok_or(ErrorCode::Overflow)?;

let share = total
    .checked_div(denominator)
    .ok_or(ErrorCode::DivisionByZero)?;

// For Decimal types (token amounts)
let liquidity = Decimal::from(collateral_amount)
    .try_div(rate)?
    .try_floor_u64()?;  // Not try_round_u64()!

PDA and Account Security Checklist

Canonical bump: PDAs use bump in seeds constraint (not hardcoded)
Unique seeds: Seeds include unique identifier (user pubkey, mint, etc.)
No duplicate accounts: Same account not used twice as mutable
Init vs init_if_needed: Uses init with proper validation, not init_if_needed
has_one constraints: Related accounts validated with has_one
Custom constraints: Complex validation uses constraint expression
Seed collision: Seeds designed to prevent collisions

// Secure PDA patterns
#[account(
    init,
    payer = authority,
    space = 8 + UserAccount::INIT_SPACE,
    seeds = [
        b"user",
        authority.key().as_ref(),  // Unique to user
        mint.key().as_ref(),        // Unique to mint
    ],
    bump
)]
pub user_account: Account<'info, UserAccount>,

CPI Security Checklist

For all Cross-Program Invocations:

Program validation: Target program is validated (uses Program<'info, T>)
Signer seeds: PDA signers pass seeds correctly in invoke_signed
Return value checking: CPI success doesn't guarantee correct state
Account reloading: Reload accounts after CPI that may modify them
No arbitrary CPI: Program account is not user-controlled
Privilege escalation: CPI doesn't grant unexpected permissions

// Secure CPI pattern
#[derive(Accounts)]
pub struct SecureCPI<'info> {
    pub token_program: Program<'info, Token>,  // Type-validated
    // ... other accounts
}

pub fn secure_cpi(ctx: Context<SecureCPI>) -> Result<()> {
    // CPI with validated program
    token::transfer(
        CpiContext::new(
            ctx.accounts.token_program.to_account_info(),
            Transfer {
                from: ctx.accounts.from.to_account_info(),
                to: ctx.accounts.to.to_account_info(),
                authority: ctx.accounts.authority.to_account_info(),
            },
        ),
        amount,
    )?;

    // Reload account after CPI
    ctx.accounts.from.reload()?;

    // Validate expected state
    require!(
        ctx.accounts.from.amount == expected_amount,
        ErrorCode::InvalidState
    );

    Ok(())
}

Oracle and External Data Checklist

For Pyth, Switchboard, or other oracles:

Oracle status: Validates oracle is in valid state (Trading status for Pyth)
Price staleness: Checks timestamp is recent enough
Oracle owner: Validates oracle account owner is correct program
Confidence interval: For Pyth, checks confidence is acceptable
Price validity: Validates price is within reasonable bounds
Fallback handling: Has strategy for oracle failure

// Pyth oracle validation
pub fn validate_pyth_price(
    pyth_account: &AccountInfo,
    clock: &Clock,
) -> Result<i64> {
    // Validate owner
    require_keys_eq!(
        *pyth_account.owner,
        PYTH_PROGRAM_ID,
        ErrorCode::InvalidOracle
    );

    let price_data = pyth_account.try_borrow_data()?;
    let price_feed = load_price_feed_from_account_info(pyth_account)?;

    // Check status
    require!(
        price_feed.agg.status == PriceStatus::Trading,
        ErrorCode::InvalidOracleStatus
    );

    // Check staleness (e.g., max 60 seconds old)
    let max_age = 60;
    require!(
        clock.unix_timestamp - price_feed.agg.publish_time <= max_age,
        ErrorCode::StalePrice
    );

    // Check confidence (example: max 1% of price)
    let confidence_threshold = price_feed.agg.price / 100;
    require!(
        price_feed.agg.conf <= confidence_threshold as u64,
        ErrorCode::OracleConfidenceTooLow
    );

    Ok(price_feed.agg.price)
}

Token Program Security Checklist

SPL Token Checks

ATA validation: Associated Token Accounts validated correctly
Mint authority: Proper checks on mint authority for minting operations
Freeze authority: Handles frozen accounts appropriately
Delegate handling: Resets delegate when needed
Close authority: Resets close authority on owner change

Token-2022 Specific Checks

Transfer hooks: Handles transfer hook extensions correctly
Extension data: Validates all active extensions
Confidential transfers: Properly handles confidential transfer extension
Transfer fees: Respects transfer fee extension
Permanent delegate: Checks for permanent delegate extension
Additional rent: Accounts for extension rent requirements

// Token-2022 with extensions
use spl_token_2022::extension::{
    BaseStateWithExtensions,
    StateWithExtensions,
};

pub fn safe_token_2022_transfer(
    /* accounts */
) -> Result<()> {
    // Check for transfer hook
    let mint_data = mint.try_borrow_data()?;
    let mint_with_extensions = StateWithExtensions::<Mint>::unpack(&mint_data)?;

    if let Ok(transfer_hook) = mint_with_extensions.get_extension::<TransferHook>() {
        // Handle transfer hook properly
        // ... transfer hook logic
    }

    // Check for transfer fee
    if let Ok(transfer_fee_config) = mint_with_extensions.get_extension::<TransferFeeConfig>() {
        // Calculate and handle fees
        // ... fee logic
    }

    // Proceed with transfer
    Ok(())
}

Architecture Review Checklist

PDA design: PDAs used appropriately vs keypair accounts
Account space: Space calculation uses InitSpace derive
Error handling: Custom errors with descriptive messages
Event emission: Critical state changes emit events
Rent exemption: All accounts are rent-exempt
Transaction size: Stays within ~1232 byte limit
Compute budget: Optimized to stay under compute limits
Upgradeability: Considers upgrade path and account versioning

Testing Checklist

Unit tests: Each instruction has unit tests
Fuzz tests: Arithmetic operations have fuzz tests (Trident)
Integration tests: Realistic multi-instruction scenarios
Negative tests: Tests for expected failures
PDA tests: Tests for seed collisions
Edge cases: Zero amounts, max values, overflow boundaries
Concurrency: Tests for transaction ordering issues
Devnet testing: Deployed and tested on devnet

// Example test structure
#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_normal_case() {
        // Test expected behavior
    }

    #[test]
    #[should_panic(expected = "Overflow")]
    fn test_overflow() {
        // Test arithmetic overflow protection
    }

    #[test]
    fn test_unauthorized_access() {
        // Test fails with wrong signer
    }

    #[test]
    fn test_edge_case_zero_amount() {
        // Test zero amount handling
    }
}

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