verify_range

The core verification instruction. Verifies that a message was signed by the trusted backend and that the signature is valid for the transaction signer.

Signature

pub fn verify_range(
    ctx: Context<VerifyRange>,
    signature: [u8; 64],
    message: Vec<u8>,
) -> Result<()>

Parameters

Parameter	Type	Description
signature	[u8; 64]	Ed25519 signature from the backend
message	Vec<u8>	The signed message bytes

Accounts

Account	Type	Description
signer	Signer	Transaction signer (must match pubkey in message)
settings	Account<Settings>	Settings PDA containing verification config
instructions_sysvar	AccountInfo	Instructions sysvar for Ed25519 verification

Message Format

The message must follow this format:

{timestamp}_{pubkey}

• timestamp: Unix timestamp (seconds) when the backend signed
• pubkey: Base58-encoded public key of the user

Example: 1704067200_7xKXtg2CW87d97TXJSDpbD5jBkheTqA83TZRuJosgAsU

Usage

TypeScript

import { buildVerifyRangeInstruction } from './codama-ts-range-custom';

const instruction = await buildVerifyRangeInstruction({
  signer: userPublicKey,
  admin: settingsAdminPublicKey,
  signature: new Uint8Array(signatureBytes),
  message: new Uint8Array(messageBytes),
});

const transaction = new Transaction().add(instruction);
await sendTransaction(transaction);

Anchor

await program.methods
  .verifyRange(
    Array.from(signature),
    Buffer.from(message)
  )
  .accounts({
    signer: user.publicKey,
    settings: settingsPda,
    instructionsSysvar: SYSVAR_INSTRUCTIONS_PUBKEY,
  })
  .rpc();

Verification Steps

The instruction performs these checks in order:

1. Signature Verification: Verify Ed25519 signature against settings.range_signer
2. Message Parsing: Extract timestamp and pubkey from message
3. Timestamp Validation: Check timestamp is within settings.window_size
4. Signer Validation: Verify message pubkey matches transaction signer

Errors

Error	Code	Cause
CouldntVerifySignature	6005	Signature doesn’t match range_signer
TimestampParsingFailed	6000	Invalid timestamp in message
PubkeyParsingFailed	6001	Invalid pubkey in message
WrongMessageSplitLength	6002	Message format incorrect
WrongSigner	6003	Message pubkey doesn’t match tx signer
TimestampOutOfWindow	6004	Signature expired or from future

Complete Example

import { Connection, Keypair, Transaction } from '@solana/web3.js';
import { buildVerifyRangeInstruction } from './codama-ts-range-custom';
import nacl from 'tweetnacl';

async function verifySignature(
  connection: Connection,
  user: Keypair,
  settingsAdmin: PublicKey,
  rangeSignerKeypair: Keypair // Backend's keypair
) {
  // 1. Create the message (normally done on backend)
  const timestamp = Math.floor(Date.now() / 1000);
  const message = `${timestamp}_${user.publicKey.toBase58()}`;
  const messageBytes = Buffer.from(message);

  // 2. Sign with backend key (normally done on backend)
  const signature = nacl.sign.detached(
    messageBytes,
    rangeSignerKeypair.secretKey
  );

  // 3. Create verification instruction
  const instruction = await buildVerifyRangeInstruction({
    signer: user.publicKey,
    admin: settingsAdmin,
    signature: new Uint8Array(signature),
    message: new Uint8Array(messageBytes),
  });

  // 4. Send transaction
  const transaction = new Transaction().add(instruction);
  transaction.feePayer = user.publicKey;
  transaction.recentBlockhash = (await connection.getLatestBlockhash()).blockhash;
  transaction.sign(user);

  const txSignature = await connection.sendRawTransaction(transaction.serialize());
  console.log('Verification successful:', txSignature);
}

Events

On success, emits a VerificationSuccess event:

{
  signer: Pubkey,
  timestamp: i64,
  signature: [u8; 64],
  message: Vec<u8>,
  clock_slot: u64,
  clock_timestamp: i64,
  settings_admin: Pubkey,
}

See Events for details on listening to events.

Tip

Use verify_range when you just need verification. If you need to trigger additional logic after verification, use verify_range_with_callback instead.

See Also

• verify_range_with_callback - Verification with CPI callback
• Quick Start - End-to-end example
• Errors - Error handling guide