Signature Algorithm

package main

import (
    "crypto/ed25519"
    "encoding/base64"
    "strings"
)

var sampleSignKey = "Qd2XliU6/I6YD3OELdeBQ57z6Q9/OHGBTjCNVLB8s/1KpvoU6aiuuBTgQ72IW/yA0aYYnfbCX31zhJKsPnRE5Q=="

func sign(msg string) string {
    signKey, _ := base64.StdEncoding.DecodeString(sampleSignKey)
    signature := ed25519.Sign(ed25519.PrivateKey(signKey), []byte(msg))
    return base64.StdEncoding.EncodeToString(signature)
}

func main() {
    params := []string{
        "1000000",  // amount
        "",         // callback
        "56",       // chain_id
        "",         // currency
        "0x0000000000000000000000000000000000000000", // recipient
        "rmtbPVEKwLzz27Qs51Jio",                      // reference_no
        "0x55d398326f99059ff775485246999027b3197955", // token_address
    }
    signMessage := strings.Join(params, "_")
    signMessage = strings.ToLower(signMessage)
    signature := sign(signMessage)
    println("Message:", signMessage)
    println("Signature:", signature)
}