Java 签名示例

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import java.util.UUID;

public class CashierSignUtil {

    public static String signHmacSha256(String message, String secret) throws Exception {
        Mac mac = Mac.getInstance("HmacSHA256");
        SecretKeySpec keySpec = new SecretKeySpec(
                secret.getBytes(StandardCharsets.UTF_8), "HmacSHA256");
        mac.init(keySpec);
        byte[] hash = mac.doFinal(message.getBytes(StandardCharsets.UTF_8));
        return Base64.getEncoder().encodeToString(hash);
    }

    public static String buildSignString(String method, String uri, String timestamp,
                                          String nonce, String body) {
        return method + "\n"
                + uri + "\n"
                + timestamp + "\n"
                + nonce + "\n"
                + (body != null ? body : "") + "\n";
    }

    public static String buildAuthorization(String mchid, String serial,
                                             String nonce, String timestamp, String signature) {
        return "KP-CASHIER-HMAC-SHA256"
                + " mchid=\"" + mchid + "\""
                + ", serial=\"" + serial + "\""
                + ", nonce=\"" + nonce + "\""
                + ", timestamp=\"" + timestamp + "\""
                + ", signature=\"" + signature + "\"";
    }

    public static String buildClientHeader(String sn, String name, String ip,
                                            String app, String version, String session) {
        StringBuilder sb = new StringBuilder();
        sb.append("sn=\"").append(sn).append("\"");
        sb.append(", name=\"").append(name).append("\"");
        sb.append(", ip=\"").append(ip).append("\"");
        sb.append(", app=\"").append(app).append("\"");
        sb.append(", version=\"").append(version).append("\"");
        if (session != null && !session.isEmpty()) {
            sb.append(", session=\"").append(session).append("\"");
        }
        return sb.toString();
    }

    public static void main(String[] args) throws Exception {
        String method = "POST";
        String uri = "/open/cashier/trans/micropay";
        String timestamp = String.valueOf(System.currentTimeMillis() / 1000);
        String nonce = UUID.randomUUID().toString().replace("-", "");
        String body = "{\"amount\":100,\"out_trade_no\":\"TS20260507000001\",\"auth_code\":\"134567890123456789\"}";
        String secret = "your_secret_key";

        String signString = buildSignString(method, uri, timestamp, nonce, body);
        String signature = signHmacSha256(signString, secret);
        String authorization = buildAuthorization("100001", "KEY001", nonce, timestamp, signature);
        String clientHeader = buildClientHeader("SN-DEVICE-001", "收银台A01", "192.168.1.100", "cashier-pos", "2.0.0", "abc123");

        System.out.println("Authorization: " + authorization);
        System.out.println("Ikudot-Cashier-Client: " + clientHeader);
    }
}

AES 加解密

部分敏感字段（如支付密码）需使用 AES-256-CBC 加密后传输。

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.SecureRandom;
import java.util.Base64;

public class AesCbcUtil {

    private static final String ALGORITHM = "AES/CBC/PKCS5Padding";
    private static final int IV_LENGTH = 16;

    public static EncryptedData encrypt(String plaintext, String base64Key) throws Exception {
        byte[] key = Base64.getDecoder().decode(base64Key);
        byte[] iv = new byte[IV_LENGTH];
        SecureRandom.getInstanceStrong().nextBytes(iv);

        Cipher cipher = Cipher.getInstance(ALGORITHM);
        SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
        IvParameterSpec ivSpec = new IvParameterSpec(iv);
        cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);

        byte[] ciphertext = cipher.doFinal(plaintext.getBytes(StandardCharsets.UTF_8));

        EncryptedData result = new EncryptedData();
        result.algorithm = "AES_256_CBC";
        result.ciphertext = Base64.getEncoder().encodeToString(ciphertext);
        result.iv = Base64.getEncoder().encodeToString(iv);
        return result;
    }

    public static String decrypt(String base64Ciphertext, String base64Iv, String base64Key) throws Exception {
        byte[] key = Base64.getDecoder().decode(base64Key);
        byte[] iv = Base64.getDecoder().decode(base64Iv);
        byte[] ciphertext = Base64.getDecoder().decode(base64Ciphertext);

        Cipher cipher = Cipher.getInstance(ALGORITHM);
        SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
        IvParameterSpec ivSpec = new IvParameterSpec(iv);
        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);

        byte[] plaintext = cipher.doFinal(ciphertext);
        return new String(plaintext, StandardCharsets.UTF_8);
    }

    public static class EncryptedData {
        public String algorithm;
        public String ciphertext;
        public String iv;
    }

    public static void main(String[] args) throws Exception {
        String aesKey = "Base64EncodedAesKey==";
        String plaintext = "123456";

        EncryptedData encrypted = encrypt(plaintext, aesKey);
        System.out.println("加密结果: algorithm=" + encrypted.algorithm
                + ", ciphertext=" + encrypted.ciphertext
                + ", iv=" + encrypted.iv);

        String decrypted = decrypt(encrypted.ciphertext, encrypted.iv, aesKey);
        System.out.println("解密结果: " + decrypted);
    }
}