feat: AES-256-GCM 암호화 적용 (tel, email), 로그/배포 설정 추가

src/main/java/com/owrawww/util/AesUtil.java

@@ -0,0 +1,78 @@
+package com.owrawww.util;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import javax.crypto.Cipher;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.GCMParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+import java.security.SecureRandom;
+import java.util.Base64;
+
+/**
+ * AES-256-GCM 암호화/복호화 유틸리티
+ * - IV(12 bytes) + 암호문을 Base64로 인코딩하여 저장
+ */
+@Component
+public class AesUtil {
+
+    private static final String ALGORITHM   = "AES/GCM/NoPadding";
+    private static final int    IV_LENGTH   = 12;   // GCM 권장 IV 크기
+    private static final int    TAG_BIT_LEN = 128;  // GCM 인증 태그 크기
+
+    private final SecretKey secretKey;
+
+    public AesUtil(@Value("${app.encryption.key}") String base64Key) {
+        byte[] keyBytes = Base64.getDecoder().decode(base64Key);
+        if (keyBytes.length != 32) {
+            throw new IllegalArgumentException("암호화 키는 Base64 인코딩된 32바이트(256bit)여야 합니다.");
+        }
+        this.secretKey = new SecretKeySpec(keyBytes, "AES");
+    }
+
+    /**
+     * 평문 → AES-256-GCM 암호화 → Base64 문자열
+     */
+    public String encrypt(String plainText) {
+        if (plainText == null || plainText.isEmpty()) return plainText;
+        try {
+            byte[] iv = new byte[IV_LENGTH];
+            new SecureRandom().nextBytes(iv);
+
+            Cipher cipher = Cipher.getInstance(ALGORITHM);
+            cipher.init(Cipher.ENCRYPT_MODE, secretKey, new GCMParameterSpec(TAG_BIT_LEN, iv));
+            byte[] encrypted = cipher.doFinal(plainText.getBytes("UTF-8"));
+
+            // IV + 암호문 결합 후 Base64 인코딩
+            byte[] combined = new byte[IV_LENGTH + encrypted.length];
+            System.arraycopy(iv, 0, combined, 0, IV_LENGTH);
+            System.arraycopy(encrypted, 0, combined, IV_LENGTH, encrypted.length);
+
+            return Base64.getEncoder().encodeToString(combined);
+        } catch (Exception e) {
+            throw new RuntimeException("암호화 실패", e);
+        }
+    }
+
+    /**
+     * Base64 암호문 → AES-256-GCM 복호화 → 평문
+     */
+    public String decrypt(String encryptedText) {
+        if (encryptedText == null || encryptedText.isEmpty()) return encryptedText;
+        try {
+            byte[] combined = Base64.getDecoder().decode(encryptedText);
+            byte[] iv        = new byte[IV_LENGTH];
+            byte[] cipherText = new byte[combined.length - IV_LENGTH];
+
+            System.arraycopy(combined, 0, iv, 0, IV_LENGTH);
+            System.arraycopy(combined, IV_LENGTH, cipherText, 0, cipherText.length);
+
+            Cipher cipher = Cipher.getInstance(ALGORITHM);
+            cipher.init(Cipher.DECRYPT_MODE, secretKey, new GCMParameterSpec(TAG_BIT_LEN, iv));
+            return new String(cipher.doFinal(cipherText), "UTF-8");
+        } catch (Exception e) {
+            throw new RuntimeException("복호화 실패", e);
+        }
+    }
+}