Merge pull request #19 from Re-4aliens/feat/#14_encod

Feat/#14 대칭키 암호화, 복호화 기능 구현

src/main/java/com/aliens/backend/encode/EncoderProperties.java

@@ -0,0 +1,27 @@
+package com.aliens.backend.encode;
+
+import jakarta.annotation.PostConstruct;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import javax.crypto.spec.SecretKeySpec;
+import java.nio.charset.StandardCharsets;
+
+@Component
+public class EncoderProperties {
+
+    @Value("${encode.symmetric.key}")
+    private String secretKey;
+
+    private SecretKeySpec encodeKey;
+
+    @PostConstruct
+    public void init() {
+        byte[] byteKey = secretKey.getBytes(StandardCharsets.UTF_8);
+        encodeKey = new SecretKeySpec(byteKey, "AES");
+    }
+
+    public SecretKeySpec getEncodeKey() {
+        return encodeKey;
+    }
+}

src/main/java/com/aliens/backend/encode/SymmetricKeyEncoder.java

@@ -0,0 +1,32 @@
+package com.aliens.backend.encode;
+
+import org.springframework.stereotype.Component;
+
+import javax.crypto.Cipher;
+import java.nio.charset.StandardCharsets;
+import java.util.Base64;
+
+@Component
+public class SymmetricKeyEncoder {
+
+    private final EncoderProperties encoderProperties;
+
+    public SymmetricKeyEncoder(final EncoderProperties encoderProperties) {
+        this.encoderProperties = encoderProperties;
+    }
+
+    public String encrypt(String plaintext) throws Exception {
+        Cipher cipher = Cipher.getInstance("AES");
+        cipher.init(Cipher.ENCRYPT_MODE, encoderProperties.getEncodeKey());
+        byte[] encryptedBytes = cipher.doFinal(plaintext.getBytes(StandardCharsets.UTF_8));
+        return Base64.getEncoder().encodeToString(encryptedBytes);
+    }
+
+    public String decrypt(String ciphertext) throws Exception {
+        Cipher cipher = Cipher.getInstance("AES");
+        cipher.init(Cipher.DECRYPT_MODE, encoderProperties.getEncodeKey());
+        byte[] decodedBytes = Base64.getDecoder().decode(ciphertext);
+        byte[] decryptedBytes = cipher.doFinal(decodedBytes);
+        return new String(decryptedBytes, StandardCharsets.UTF_8);
+    }
+}

src/test/java/com/aliens/backend/encode/SymmetricKeyEncoderTest.java

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+package com.aliens.backend.encode;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class SymmetricKeyEncoderTest {
+
+    @Autowired
+    private SymmetricKeyEncoder symmetricKeyEncoder;
+
+    @Test
+    @DisplayName("문자열 암호화 성공")
+    void encryptTest() throws Exception {
+        //Given
+        String givenInput = "testText";
+
+        //When
+        String result = symmetricKeyEncoder.encrypt(givenInput);
+
+        //Then
+        Assertions.assertNotEquals(result, givenInput);
+    }
+
+    @Test
+    @DisplayName("문자열 복호화 성공")
+    void decryptTest() throws Exception {
+        //Given
+        String givenInput = "testText";
+        String code = symmetricKeyEncoder.encrypt(givenInput);
+
+        //When
+        String result = symmetricKeyEncoder.decrypt(code);
+
+        //Then
+        Assertions.assertEquals(result, givenInput);
+    }
+}