iY5VR7A3

1import java.nio.charset.StandardCharsets;
2import java.security.InvalidKeyException;
3import java.security.MessageDigest;
4import java.security.NoSuchAlgorithmException;
5import java.security.NoSuchAlgorithmException;
6import java.util.Base64;
7
8import javax.crypto.Mac;
9import javax.crypto.spec.SecretKeySpec;
10
11class Main {
12  public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeyException {
13    String secret = "Oe8TBDzg4tatdq2cL9ojeEj3U3oWSCSC5fqOHAqaKVg";
14    String method = "POST";
15    String body = "{\"amount\":\"100\"}";
16    String date = "2019-01-09T11:24:40+00:00";
17    String path = "/api/auth/test";
18    String contentType = "application/json";
19
20    // 5173e4d02d8a761679b0165b87d9ee5f
21    String bodyMD5 = body.isEmpty() ? "" : md5hex(body);
22
23    // POST\n5173e4d02d8a761679b0165b87d9ee5f\napplication/json\n2019-01-09T11:24:40+00:00\n/api/auth/test
24    String stringToSign = String.join("\n", method, bodyMD5, contentType, date, path);
25
26    // fVYzUdYqZO1ozBeP3KQHFp9/Kno=
27    String signature = hmac(stringToSign, secret);
28
29    System.out.println(signature);
30  }
31
32  private static String md5hex(String str) throws NoSuchAlgorithmException {
33    MessageDigest md5 = MessageDigest.getInstance("MD5");
34    byte[] bytes = md5.digest(str.getBytes(StandardCharsets.UTF_8));
35
36    return hex(bytes);
37  }
38
39  private static String hmac(String str, String secret) throws InvalidKeyException, NoSuchAlgorithmException {
40    SecretKeySpec secretKey = new SecretKeySpec(secret.getBytes(StandardCharsets.UTF_8), "HmacSHA1");
41
42    Mac mac = Mac.getInstance("HmacSHA1");
43    mac.init(secretKey);
44    byte[] result = mac.doFinal(str.getBytes(StandardCharsets.UTF_8));
45
46    String base64 = Base64.getEncoder().encodeToString(result);
47
48    return base64;
49  }
50
51  private static String hex(byte[] bytes) {
52    StringBuilder sb = new StringBuilder();
53
54    for (byte b : bytes) {
55      sb.append(String.format("%02x", b));
56    }
57
58    return sb.toString();
59  }
60}