feat(security): 添加 RSA 非对称加密工具类

新增 `RSA` 工具类，封装 RSA 加解密功能。

当前为 Beta 版本，后续需完善测试和文档。

cspell.json

@@ -31,6 +31,7 @@
         "mybatis",
         "Nonnull",
         "NOSONAR",
+        "OAEP",
         "okhttp",
         "okio",
         "ooxml",

plusone-commons/src/main/java/xyz/zhouxy/plusone/commons/security/RSA.java

@@ -0,0 +1,115 @@
+/*
+ * Copyright 2025 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package xyz.zhouxy.plusone.commons.security;
+
+import java.math.BigInteger;
+import java.nio.charset.StandardCharsets;
+import java.security.GeneralSecurityException;
+import java.security.KeyPair;
+import java.security.KeyPairGenerator;
+import java.security.NoSuchAlgorithmException;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+
+import javax.crypto.Cipher;
+
+import com.google.common.annotations.Beta;
+
+// TODO [优化] 优化实现
+// TODO [测试] 添加单元测试
+// TODO [doc] javadoc、README.md、模块介绍、package-info.java
+
+/**
+ * RSA 非对称加密
+ *
+ * @author ZhouXY108 <luquanlion@outlook.com>
+ * @since 1.1.0
+ */
+@Beta
+public class RSA {
+    private static final int DEFAULT_KEY_SIZE = 2048;
+    public static final String NAME = "RSA";
+    private static final String TRANSFORMATION = "RSA/ECB/OAEPWithSHA-256AndMGF1Padding";
+
+    private final PublicKey publicKey;
+    private final PrivateKey privateKey;
+
+    private RSA(final PublicKey publicKey, final PrivateKey privateKey) {
+        this.publicKey = publicKey;
+        this.privateKey = privateKey;
+    }
+
+    public static RSA of(final PublicKey publicKey, final PrivateKey privateKey) {
+        return new RSA(publicKey, privateKey);
+    }
+
+    public static RSA of(final KeyPair keyPair) {
+        return new RSA(keyPair.getPublic(), keyPair.getPrivate());
+    }
+
+    public static RSA withKeySize(int keySize) {
+        try {
+            KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(NAME);
+            keyPairGenerator.initialize(keySize);
+            final KeyPair keyPair = keyPairGenerator.generateKeyPair();
+            return new RSA(keyPair.getPublic(), keyPair.getPrivate());
+        }
+        catch (NoSuchAlgorithmException e) {
+            throw new SecurityException(e);
+        }
+    }
+
+    public static RSA withDefaultKeySize() {
+        return withKeySize(DEFAULT_KEY_SIZE);
+    }
+
+    public PrivateKey getPrivateKey() {
+        return privateKey;
+    }
+
+    public PublicKey getPublicKey() {
+        return publicKey;
+    }
+
+    public byte[] encrypt(byte[] input) throws GeneralSecurityException {
+        Cipher encryptModeCipher = Cipher.getInstance(TRANSFORMATION);
+        encryptModeCipher.init(Cipher.ENCRYPT_MODE, publicKey);
+        return encryptModeCipher.doFinal(input);
+    }
+
+    public byte[] encrypt(String input) throws GeneralSecurityException {
+        return encrypt(input.getBytes(StandardCharsets.UTF_8));
+    }
+
+    public String encryptToString(String input) throws GeneralSecurityException {
+        return new BigInteger(1, encrypt(input)).toString(16);
+    }
+
+    public byte[] decrypt(byte[] input) throws GeneralSecurityException {
+        Cipher decryptModeCipher = Cipher.getInstance(TRANSFORMATION);
+        decryptModeCipher.init(Cipher.DECRYPT_MODE, privateKey);
+        return decryptModeCipher.doFinal(input);
+    }
+
+    public byte[] decrypt(String input) throws GeneralSecurityException {
+        return decrypt(new BigInteger(input, 16).toByteArray());
+    }
+
+    public String decryptToString(String input) throws GeneralSecurityException {
+        return new String(decrypt(input));
+    }
+}