Validation

EVM

contract Dex {
  bool private _paused;
  
  function setPaused(bool paused) external {
    if (msg.sender != owner) {
      revert NotOwner();
    }
    
    _paused = paused;
  }
}

Solana

1. Using constraint

#[account]
pub struct Config {
  pub authority: Pubkey,
  pub paused: bool,
}

#[derive(Accounts)]
pub struct SetPaused<'info> {
  pub signer: Signer<'info>,
  
  #[account(mut, constraint = config.authority == signer.key() @ ErrorCode::Unauthorized)]
  pub config: Account<'info, Config>
}


pub fn set_paused(Context<SetPaused, bool paused) -> Result<()> {
  ctx.accounts.config.paused = paused;
}

1. Using require!

#[account]
pub struct Config {
  pub authority: Pubkey,
  pub paused: bool,
}

#[derive(Accounts)]
pub struct SetPaused<'info> {
  pub signer: Signer<'info>,
  
  #[account(mut, constraint = config.authority == signer.key() @ ErrorCode::Unauthorized)]
  pub config: Account<'info, Config>
}


pub fn set_paused(Context<SetPaused, bool paused) -> Result<()> {
  require!(ctx.accounts.config.authority == ctx.accounts.signer.key(), ErrorCode::Unauthorized);
  ctx.accounts.config.paused = paused;
}

1. Using has_one

Notice how I've changed the caller's field name from signer to authority. has_one is looking for an account called authority that matches the account config's authority.

#[account]
pub struct Config {
  pub authority: Pubkey,
  pub paused: bool,
}

#[derive(Accounts)]
pub struct SetPaused<'info> {
  pub authority: Signer<'info>,
  
  #[account(mut, has_one = authority) @ ErrorCode::Unauthorized)]
  pub config: Account<'info, Config>
}


pub fn set_paused(Context<SetPaused, bool paused) -> Result<()> {
  ctx.accounts.config.paused = paused;
}