Simple Message Queue (formerly MNS)：Verifikasi tanda tangan pada server HTTP

Langkah 1: Ambil Sertifikat X509

Dalam permintaan HTTP yang dikirim dari SMQ ke titik akhir, header x-mns-signing-cert-url menentukan string yang menunjukkan URL sertifikat tanda tangan. Anda harus mendekode Base64 pada string tersebut untuk mengambil URL sertifikat tanda tangan dan mendapatkan kunci publik dari sertifikat.

Langkah 2: Hitung nilai string-to-sign

Buat string-to-sign berdasarkan pseudocode berikut:

StringToSign = HttpMethod + "\n" 
         + CONTENT-MD5 + "\n"     
         + CONTENT-TYPE + "\n" 
         + DATE + "\n" 
         + CanonicalizedMNSHeaders
         + CanonicalizedResource;

Tabel berikut menjelaskan parameter.

Contoh:

POST
ZDgxNjY5ZjFlMDQ5MGM0YWMwMWE5ODlmZDVlYmQxYjI=
text/xml;charset=utf-8
Wed, 25 May 2016 10:46:14 GMT
x-mns-request-id:57458276F0E3D56D7C00****
x-mns-signing-cert-url:aHR0cDovL21uc3Rlc3Qub3NzLWNuLWhhbmd6aG91LmFsaXl1bmNzLmNvbS94NTA5X3B1YmxpY19jZXJ0aWZpY2F0ZS5w****
x-mns-version:2015-06-06
/notifications       

Langkah 3: Dekripsi header Authorization

Setelah melakukan dekode Base64 pada header Authorization, Anda dapat mendekripsi nilai yang didekode menggunakan kunci publik yang diambil di Langkah 1.

Langkah 4: Verifikasi tanda tangan

Bandingkan string-to-sign yang dihasilkan di Langkah 2 dengan string yang didekripsi yang dihasilkan di Langkah 3. Jika kedua string sama, permintaan dari SMQ valid. Jika tidak, tolak permintaan.

Contoh kode Java

import org.apache.commons.codec.binary.Base64;

import java.io.DataInputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.PublicKey;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


public class SignDemo {
    private Boolean authenticate(String method, String uri, Map<String, String> headers) {
        try {
            // Ambil URL sertifikat tanda tangan. 
            if (!headers.containsKey("x-mns-signing-cert-url")) {
                System.out.println("Header x-mns-signing-cert-url tidak ditemukan");
                return false;
            }
            String cert = headers.get("x-mns-signing-cert-url");
            if (cert.isEmpty()) {
                System.out.println("x-mns-signing-cert-url kosong");
                return false;
            }
            cert = new String(Base64.decodeBase64(cert));
            System.out.println("x-mns-signing-cert-url:\t" + cert);

            // Gunakan URL untuk mengambil sertifikat dan ambil kunci publik dari sertifikat. 
            URL url = new URL(cert);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            DataInputStream in = new DataInputStream(conn.getInputStream());
            CertificateFactory cf = CertificateFactory.getInstance("X.509");
            Certificate c = cf.generateCertificate(in);
            PublicKey pk = c.getPublicKey();

            // Ambil string-to-sign. 
            String str2sign = getSignStr(method, uri, headers);
            System.out.println("String2Sign:\t" + str2sign);

            // Dekode header Authorization dalam Base64. 
            String signature = headers.get("Authorization");
            byte[] decodedSign = Base64.decodeBase64(signature);

            // Verifikasi tanda tangan. 
            java.security.Signature signetcheck = java.security.Signature.getInstance("SHA1withRSA");
            signetcheck.initVerify(pk);
            signetcheck.update(str2sign.getBytes());
            Boolean res = signetcheck.verify(decodedSign);
            return res;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    private String getSignStr(String method, String uri, Map<String, String> headers) {
        StringBuilder sb = new StringBuilder();
        sb.append(method);
        sb.append("\n");
        sb.append(safeGetHeader(headers, "Content-md5"));
        sb.append("\n");
        sb.append(safeGetHeader(headers, "Content-Type"));
        sb.append("\n");
        sb.append(safeGetHeader(headers, "Date"));
        sb.append("\n");

        List<String> tmp = new ArrayList<String>();
        for (Map.Entry<String, String> entry : headers.entrySet()) {
            if (entry.getKey().startsWith("x-mns-")) {
                tmp.add(entry.getKey() + ":" + entry.getValue());
            }
        }
        Collections.sort(tmp);

        for (String kv : tmp) {
            sb.append(kv);
            sb.append("\n");
        }

        sb.append(uri);
        return sb.toString();
    }

    private String safeGetHeader(Map<String, String> headers, String name) {
        if (headers.containsKey(name)) {
            return headers.get(name);
        } else {
            return "";
        }
    }

    public static void main(String[] args) {
        SignDemo sd = new SignDemo();
        Map<String, String> headers = new HashMap<String, String>();
        headers.put("Authorization", "Mko2Azg9fhCw8qR6G7AeAFMyzjO9qn7LDA5/t9E+6X5XURXTqBUuhpK+K55UNhrnlE2UdDkRrwDxsaDP5ajQ****");
        headers.put("Content-md5", "M2ViOTE2ZDEyOTlkODBjMjVkNzM4YjNhNWI3ZWQ1****");
        headers.put("Content-Type", "text/xml;charset=utf-8");
        headers.put("Date", "Tue, 23 Feb 2016 09:41:06 GMT");
        headers.put("x-mns-request-id", "56CC2932F0E3D5BD5306****");
        headers.put("x-mns-signing-cert-url", "aHR0cDovL21uc3Rlc3Qub3NzLWNuLWhhbmd6aG91LmFsaXl1bmNzLmNvbS94NTA5X3B1YmxpY19jZXJ0aWZpY2F0ZS5w****");
        headers.put("x-mns-version", "2015-06-06");
        Boolean res = sd.authenticate("POST", "/notifications", headers);
        System.out.println("Hasil autentikasi:" + res);
    }
}