Convert encoded byte array to certificate

In my previous post, I explained how to convert certificate to byte array, in this post, I am going to show you how to convert the byte array to certificate.

Step 1: Decode encoded bytes.

byte[] encodedBytes;

Decoder decoder = Base64.getDecoder();

byte[] decodedBytes = decoder.decode(encodedBytes);

Step 2: write the byte array to the file.

try (FileOutputStream fos = new FileOutputStream(certificateFilePath)) {

         fos.write(decodedBytes);

}

Find the below working application.

Test.java

package com.sample.test;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Base64;
import java.util.Base64.Decoder;;

public class Test {
 private static final String certificateFilePath = "C:\\Users\\krishna\\myCertificate.cer";

 public static void writeBytesToFile(byte[] decodedBytes, String certificateFilePath)
   throws FileNotFoundException, IOException {
  try (FileOutputStream fos = new FileOutputStream(certificateFilePath)) {
   fos.write(decodedBytes);
  }
 }

 public static void main(String args[]) throws Exception {
  byte[] encodedBytes = { 77, 73, 73, 68, 98, 84, 67, 67, 65, 108, 87, 103, 65, 119, 73, 66, 65, 103, 73, 69, 72,
    85, 106, 56, 54, 106, 65, 78, 66, 103, 107, 113, 104, 107, 105, 71, 57, 119, 48, 66, 65, 81, 115, 70,
    65, 68, 66, 110, 77, 81, 115, 119, 67, 81, 89, 68, 86, 81, 81, 71, 69, 119, 74, 114, 99, 106, 69, 81,
    77, 65, 52, 71, 65, 49, 85, 69, 67, 66, 77, 72, 97, 51, 74, 112, 99, 50, 104, 117, 89, 84, 69, 81, 77,
    65, 52, 71, 65, 49, 85, 69, 66, 120, 77, 72, 97, 51, 74, 112, 99, 50, 104, 117, 89, 84, 69, 81, 77, 65,
    52, 71, 65, 49, 85, 69, 67, 104, 77, 72, 97, 51, 74, 112, 99, 50, 104, 117, 89, 84, 69, 81, 77, 65, 52,
    71, 65, 49, 85, 69, 67, 120, 77, 72, 97, 51, 74, 112, 99, 50, 104, 117, 89, 84, 69, 81, 77, 65, 52, 71,
    65, 49, 85, 69, 65, 120, 77, 72, 97, 51, 74, 112, 99, 50, 104, 117, 89, 84, 65, 101, 70, 119, 48, 120,
    79, 68, 65, 121, 77, 68, 107, 119, 78, 68, 69, 119, 77, 106, 74, 97, 70, 119, 48, 120, 79, 84, 65, 121,
    77, 68, 107, 119, 78, 68, 69, 119, 77, 106, 74, 97, 77, 71, 99, 120, 67, 122, 65, 74, 66, 103, 78, 86,
    66, 65, 89, 84, 65, 109, 116, 121, 77, 82, 65, 119, 68, 103, 89, 68, 86, 81, 81, 73, 69, 119, 100, 114,
    99, 109, 108, 122, 97, 71, 53, 104, 77, 82, 65, 119, 68, 103, 89, 68, 86, 81, 81, 72, 69, 119, 100, 114,
    99, 109, 108, 122, 97, 71, 53, 104, 77, 82, 65, 119, 68, 103, 89, 68, 86, 81, 81, 75, 69, 119, 100, 114,
    99, 109, 108, 122, 97, 71, 53, 104, 77, 82, 65, 119, 68, 103, 89, 68, 86, 81, 81, 76, 69, 119, 100, 114,
    99, 109, 108, 122, 97, 71, 53, 104, 77, 82, 65, 119, 68, 103, 89, 68, 86, 81, 81, 68, 69, 119, 100, 114,
    99, 109, 108, 122, 97, 71, 53, 104, 77, 73, 73, 66, 73, 106, 65, 78, 66, 103, 107, 113, 104, 107, 105,
    71, 57, 119, 48, 66, 65, 81, 69, 70, 65, 65, 79, 67, 65, 81, 56, 65, 77, 73, 73, 66, 67, 103, 75, 67,
    65, 81, 69, 65, 113, 111, 68, 80, 56, 113, 47, 76, 101, 114, 65, 73, 98, 54, 87, 66, 120, 48, 110, 120,
    51, 105, 54, 55, 48, 112, 55, 117, 119, 82, 98, 84, 81, 47, 78, 101, 75, 53, 52, 66, 69, 115, 86, 51,
    112, 107, 106, 84, 56, 71, 108, 80, 115, 84, 80, 50, 97, 105, 54, 88, 115, 48, 51, 56, 111, 89, 107,
    103, 83, 120, 108, 100, 108, 102, 104, 103, 112, 100, 88, 115, 87, 113, 104, 57, 53, 43, 89, 100, 113,
    68, 80, 74, 86, 50, 105, 70, 52, 76, 65, 69, 84, 50, 90, 57, 113, 114, 85, 67, 104, 112, 54, 77, 107,
    109, 72, 81, 114, 56, 72, 82, 105, 49, 43, 50, 85, 79, 83, 54, 87, 73, 48, 73, 88, 52, 102, 90, 97, 115,
    88, 97, 112, 76, 49, 99, 81, 67, 115, 71, 84, 89, 101, 109, 49, 98, 52, 107, 74, 109, 89, 80, 88, 99,
    122, 104, 116, 79, 77, 75, 119, 74, 88, 98, 100, 65, 48, 89, 118, 122, 69, 43, 52, 109, 50, 112, 88, 49,
    119, 106, 77, 117, 102, 105, 50, 101, 88, 56, 97, 52, 113, 117, 111, 106, 81, 106, 74, 114, 85, 82, 110,
    113, 55, 52, 47, 88, 74, 101, 112, 78, 110, 65, 48, 121, 87, 82, 117, 99, 122, 100, 76, 71, 51, 88, 112,
    80, 70, 102, 116, 81, 97, 67, 105, 65, 106, 43, 79, 97, 47, 51, 98, 75, 85, 89, 88, 82, 103, 49, 79, 68,
    100, 108, 53, 86, 84, 97, 120, 85, 107, 113, 76, 47, 50, 111, 100, 119, 52, 118, 118, 70, 115, 50, 102,
    104, 83, 110, 111, 117, 65, 76, 115, 99, 43, 119, 121, 65, 75, 97, 66, 72, 51, 56, 90, 73, 67, 85, 67,
    111, 83, 105, 88, 54, 109, 85, 57, 104, 67, 118, 66, 112, 98, 72, 70, 107, 54, 84, 111, 81, 99, 80, 84,
    111, 51, 67, 107, 87, 71, 83, 122, 66, 105, 80, 114, 81, 73, 68, 65, 81, 65, 66, 111, 121, 69, 119, 72,
    122, 65, 100, 66, 103, 78, 86, 72, 81, 52, 69, 70, 103, 81, 85, 84, 49, 83, 49, 69, 68, 50, 115, 85, 89,
    80, 67, 105, 56, 84, 104, 109, 122, 47, 116, 69, 113, 105, 83, 76, 73, 73, 119, 68, 81, 89, 74, 75, 111,
    90, 73, 104, 118, 99, 78, 65, 81, 69, 76, 66, 81, 65, 68, 103, 103, 69, 66, 65, 75, 97, 98, 88, 107, 43,
    76, 105, 102, 81, 77, 110, 65, 56, 101, 74, 118, 68, 107, 110, 56, 120, 90, 51, 70, 75, 114, 47, 57,
    111, 115, 109, 73, 99, 74, 106, 107, 79, 52, 105, 48, 118, 116, 110, 71, 79, 83, 120, 81, 52, 43, 73,
    121, 65, 84, 120, 74, 47, 52, 110, 114, 88, 65, 90, 119, 66, 73, 52, 43, 113, 52, 108, 49, 51, 71, 78,
    70, 119, 43, 83, 54, 101, 98, 75, 111, 89, 102, 78, 87, 69, 118, 90, 72, 85, 98, 106, 76, 65, 76, 114,
    57, 56, 43, 110, 104, 72, 115, 85, 82, 89, 55, 51, 84, 73, 86, 50, 110, 119, 55, 53, 98, 87, 79, 118,
    104, 51, 81, 82, 112, 68, 68, 80, 105, 80, 47, 51, 70, 122, 115, 57, 88, 106, 69, 78, 120, 101, 85, 88,
    99, 85, 86, 43, 109, 76, 71, 69, 84, 75, 71, 97, 54, 115, 122, 102, 99, 90, 48, 72, 117, 97, 101, 118,
    97, 53, 110, 120, 68, 116, 55, 85, 43, 52, 47, 51, 120, 121, 77, 79, 57, 67, 87, 117, 89, 103, 108, 104,
    67, 56, 97, 99, 116, 49, 112, 100, 51, 82, 102, 90, 100, 90, 74, 97, 68, 78, 51, 102, 85, 121, 47, 43,
    116, 111, 99, 75, 88, 77, 109, 111, 48, 115, 55, 111, 76, 105, 65, 108, 121, 102, 76, 78, 104, 110, 103,
    50, 97, 113, 72, 119, 72, 117, 47, 115, 65, 111, 72, 106, 89, 121, 76, 104, 113, 122, 55, 52, 48, 49,
    77, 109, 113, 72, 89, 88, 56, 104, 107, 79, 74, 54, 70, 66, 88, 106, 74, 90, 122, 54, 50, 122, 102, 114,
    70, 85, 86, 111, 77, 49, 48, 122, 78, 107, 66, 121, 73, 98, 100, 76, 52, 87, 122, 78, 102, 47, 100, 56,
    122, 48, 88, 53, 55, 73, 103, 72, 103, 48, 56, 73, 80, 112, 89, 74, 79, 102, 101, 110, 83, 73, 113, 70,
    51, 82, 109, 111, 61 };

  Decoder decoder = Base64.getDecoder();

  byte[] decodedBytes = decoder.decode(encodedBytes);

  writeBytesToFile(decodedBytes, certificateFilePath);
 }
}

When you ran above application, you can able to see below certificate.

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