HaiPay Configuration and Signature Guide

/**
 * Generates a 2048-bit RSA key pair and converts the public and private keys to PEM format.
 */
public static Map<String, String> generateRSAKeyPair() {
    try {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        keyPairGenerator.initialize(2048);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();

        String publicKeyPem = convertPublicKeyToPEM(keyPair.getPublic());
        String privateKeyPem = convertPrivateKeyToPEM(keyPair.getPrivate());

        Map<String, String> keyPairMap = new HashMap<>();
        keyPairMap.put("publicKey", publicKeyPem);
        keyPairMap.put("privateKey", privateKeyPem);
        return keyPairMap;
    } catch (NoSuchAlgorithmException e) {
        throw new RuntimeException("Failed to generate RSA key pair", e);
    }
}

// Remove the -----BEGIN/END PUBLIC KEY----- markers, line breaks, and spaces before uploading the public key

/**
 * Initialize an RSA key pair
 * @param int $keysize 2048 is recommended
 */
public function initRSAKey($keysize) {
    $config = array(
        "digest_alg" => "sha256",
        "private_key_bits" => $keysize,
        "private_key_type" => OPENSSL_KEYTYPE_RSA,
    );
    $rsaKey = openssl_pkey_new($config);
    openssl_pkey_export($rsaKey, $privateKey);
    $publicKey = openssl_pkey_get_details($rsaKey);
    $publicKey = $publicKey["key"];

    return array(
        'public_key' => $publicKey,
        'private_key' => $privateKey
    );
}

public static String getSign(Object obj, String secretKey) {
    Map<String, Object> map;
    if (obj instanceof Map) {
        map = (Map<String, Object>) obj;
    } else {
        map = BeanMapTool.beanToMap(obj);
    }
    Set<String> keys = map.keySet();
    List<String> list = new ArrayList<>(keys);
    Collections.sort(list);

    StringBuilder sb = new StringBuilder();
    for (String key : list) {
        Object val = map.get(key);
        if (!("".equals(val) || val == null
            || List.of("sign_type", "sign").contains(key))) {
            sb.append(key).append("=").append(val).append("&");
        }
    }
    sb.append("key=").append(secretKey);
    return sb.toString();
}

// Do not use loose empty checks such as empty()
function getSign($array, $merchantSecretKey) {
    $keys = array_keys($array);
    sort($keys, SORT_STRING);
    $str = "";
    foreach ($keys as $key) {
        $val = $array[$key];
        if ($val !== null && $val !== ''
            && $key !== "sign" && $key !== "sign_type") {
            $str .= $key . "=" . $val . "&";
        }
    }
    return $str . "key=" . $merchantSecretKey;
}

// Do not use loose checks such as if (!value)
function getSign(map, merchantSecretKey) {
    const keys = Object.keys(map).sort();
    const sb = keys.reduce((acc, key) => {
        const val = map[key];
        if (val !== "" && val !== null
            && key !== "sign" && key !== "sign_type") {
            acc.push(`${key}=${val}`);
        }
        return acc;
    }, []).join('&');
    return `${sb}&key=${merchantSecretKey}`;
}