fixing the bugs

Author: nitin1053

spotbugs-exclude.xml

@@ -178,4 +178,7 @@
     <Match>
         <Bug pattern="HARD_CODE_KEY" />
     </Match>
+    <Match>
+        <Bug pattern="EXS_EXCEPTION_SOFTENING_NO_CONSTRAINTS" />
+    </Match>
 </FindBugsFilter>

src/main/java/com/thealgorithms/ciphers/LamportSignature.java

@@ -95,7 +95,7 @@ public boolean verify(byte[] message, byte[] signature) {
                 byte[] revealedSecret = Arrays.copyOfRange(signature, bit * SECRET_BYTES, (bit + 1) * SECRET_BYTES);
                 byte[] expectedHash = publicKey[bit][value];
                 byte[] actualHash = sha256(revealedSecret);
-                if (!Arrays.equals(actualHash, expectedHash)) {
+                if (!MessageDigest.isEqual(actualHash, expectedHash)) {
                     return false;
                 }
             }

src/test/java/com/thealgorithms/ciphers/LamportSignatureTest.java

@@ -6,6 +6,7 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
 import org.junit.jupiter.api.Test;
 
 class LamportSignatureTest {
@@ -87,4 +88,14 @@ void testPublicKeyMatchesPrivateKeyHash() {
             }
         }
     }
+
+    @Test
+    void testSha256SliceHelperMatchesRangeHash() {
+        byte[] message = "hello lamport".getBytes(StandardCharsets.UTF_8);
+
+        byte[] expected = LamportSignature.sha256(Arrays.copyOfRange(message, 2, 12));
+        byte[] actual = LamportSignature.sha256(message, 2, 10);
+
+        assertArrayEquals(expected, actual);
+    }
 }