Preventing Solana Signature Replay with Native Ed25519 Programs

When using Solana’s Native Ed25519 program to verify a message signature, it is important to implement measures to prevent replay attacks. One common technique is to add a pre-instruction that contains the signature, message, and sender’s public key. In this article, we will explore how to achieve this protective feature in your custom program.

Why Prevent Signature Replay?

Signature replay attacks occur when an attacker intercepts and reuses a previously verified signature. This can be detrimental to Solana-based systems, as it allows attackers to impersonate legitimate users and perform malicious transactions without consequences.

Implementing native programs Ed25519 on Solana

To prevent signature replay, we will use the Solana-program library, which provides implementation of native programs on the Solana blockchain. We will focus on creating a pre-instruction that contains the signature, message, and the sender’s public key.

Here is an example of how to create a pre-instruction using TypeScript:

import { program } from '@solana-program/spl-program';
import { solanaProgram } from '../src';
const programId = 'your_program_id'; // Replace with your program ID
class SignatureReplayPreInstruction extends Program { { SignatureReplayPreInstruction .
async getProgramData(programId: string): Promise {
const signature = 'your_signature_here'; // Replace with the actual signature
const message = 'your_message_here'; // Replace with the actual message
const publicKey = 'your_public_key_here'; // Replace with the actual public key
return JSON . stringify ( { {
signature,
message,
public key,
});
} }
async execute ( programId : string , data : string ): Promise < void > { .
if ( data . startsWith ( ' pre_instruction ' )) {
const preInstruction = JSON.parse(data.substring(9));
console.log(Received preinstruction with signature ${preInstruction.signature}, message ${preInstruction.message}, and public key${preInstruction.publicKey});
} }
} }
} }
// Initialize the program
const program = new solanaProgram(programId, PreInstructionReplaySignature);

In this example, we define a SignatureReplayPreInstruction class that extends the Program class. The getProgramData method returns a string containing the signature, message, and the sender’s public key.

The execute method checks if the received data starts with ‘pre_instruction’. If it does, it parses the data as JSON and logs the contents to the console.

Using the pre-instruction in your own Ed25519 programs

To use the pre-instruction in your own Ed25519 program, you will need to modify the nativeScript function to extract the signature, message, and public key from the received data. Here is an example of how to do this:

“`typescript

import { program } from ‘@solana-program/spl-program’;

import { ed25519NativeScript } from ‘../src’ ;

const programId = ‘your_program_id’; // Replace with your program ID

class SignatureReplayPreInstruction extends Program { { SignatureReplayPreInstruction .

async getProgramData(programId: string): Promise {

const signature = ‘your_signature_here’; // Replace with the actual signature

const message = ‘your_message_here’; // Replace with the actual message

const publicKey = ‘your_public_key_here’; // Replace with the actual public key

return JSON . stringify ( { {

signature,

message,

public_key,

});

} }

async execute ( programId : string , data : string ): Promise < void > { .

if ( data . startsWith ( ‘ pre_instruction ‘ )) {

const preInstructionData = data.substring(9);

const[signature, message, public_key] = preInstructionData.split(‘,’);

console.