Add Blowfish Algorithm (#3052)

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

@@ -0,0 +1,43 @@
+package com.thealgorithms.ciphers;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class BlowfishTest {
+
+	Blowfish blowfish = new Blowfish();
+
+	@Test
+	void testEncrypt() {
+
+		//given
+		String plainText = "123456abcd132536";
+		String key = "aabb09182736ccdd";
+		String expectedOutput = "d748ec383d3405f7";
+		
+		//when
+		String cipherText = blowfish.encrypt(plainText, key);
+		
+		//then
+		assertEquals(expectedOutput, cipherText);
+
+	}
+	
+	@Test
+	void testDecrypt() {
+		
+		//given
+		String cipherText = "d748ec383d3405f7";
+		String key = "aabb09182736ccdd";
+		String expectedOutput = "123456abcd132536";
+		
+		//when
+		String plainText = blowfish.decrypt(cipherText, key);
+		
+		//then
+		assertEquals(expectedOutput, plainText);
+
+	}
+	
+}