Added BAEL-3604 code (#9020)

* Added BAEL-3604 code

core-java-modules/core-java-security-2/src/main/java/com/baeldung/checksums/ChecksumUtils.java

@@ -0,0 +1,23 @@
+package com.baeldung.checksums;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.zip.CRC32;
+import java.util.zip.CheckedInputStream;
+import java.util.zip.Checksum;
+
+public class ChecksumUtils {
+
+    public static long getChecksumCRC32(byte[] bytes) {
+        Checksum crc32 = new CRC32();
+        crc32.update(bytes, 0, bytes.length);
+        return crc32.getValue();
+    }
+
+    public static long getChecksumCRC32(InputStream stream, int bufferSize) throws IOException {
+        CheckedInputStream checkedInputStream = new CheckedInputStream(stream, new CRC32());
+        byte[] buffer = new byte[bufferSize];
+        while (checkedInputStream.read(buffer, 0, buffer.length) >= 0) {}
+        return checkedInputStream.getChecksum().getValue();
+    }
+}