feat: 新增安全设备 Demo 及 Android 端 TEE 加解密模块

2026-08-20 16:11:53 +08:00
commit bb33f3b5ae
31 changed files with 2803 additions and 0 deletions
--- a/android-device/DeviceCrypto.java
+++ b/android-device/DeviceCrypto.java
@@ -0,0 +1,334 @@
+package com.secure.device;
+
+import android.content.Context;
+import android.security.keystore.KeyGenParameterSpec;
+import android.security.keystore.KeyProperties;
+import java.security.KeyPair;
+import java.security.KeyPairGenerator;
+import java.security.KeyStore;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+import java.security.Signature;
+import java.util.Base64;
+import javax.crypto.Cipher;
+import javax.crypto.KeyGenerator;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.GCMParameterSpec;
+
+/**
+ * 设备端安全模块（Android）
+ * 
+ * 核心设计：
+ * - TEE 密钥对（RSA-2048）：私钥不可导出，用于解密服务端下发数据 + 签名
+ * - 每次拍照生成随机 DEK（AES-256）：用后即弃
+ * - DEK 明文通过 HTTPS 传给服务端，服务端用 UK 加密后存储
+ * 
+ * 安全边界：
+ * - 私钥永不出 TEE
+ * - SN 仅做身份标识，不参与加密
+ * - 恢复出厂 → 密钥销毁 → 新密钥对 → 用户短信验证恢复
+ */
+public class DeviceCrypto {
+
+    // ==================== 常量 ====================
+
+    private static final String KEYSTORE_PROVIDER = "AndroidKeyStore";
+    private static final String KEY_ALIAS = "device_tee_key";
+    private static final String KEY_ALGO = KeyProperties.KEY_ALGORITHM_RSA;
+    private static final int RSA_KEY_SIZE = 2048;
+    private static final String SIGN_ALGO = "SHA256withRSA";
+    private static final String RSA_TRANSFORM = "RSA/ECB/OAEPWithSHA-256AndMGF1Padding";
+    private static final int AES_KEY_SIZE = 256;
+    private static final int GCM_IV_LENGTH = 12;
+    private static final int GCM_TAG_LENGTH = 128;
+
+    private final Context context;
+    private KeyStore keyStore;
+
+    // ==================== 构造与初始化 ====================
+
+    public DeviceCrypto(Context context) {
+        this.context = context;
+        initKeyStore();
+    }
+
+    /**
+     * 初始化 AndroidKeyStore，如不存在密钥对则生成
+     * 
+     * 安全属性：
+     * - PURPOSE_DECRYPT + PURPOSE_SIGN（私钥只用于解密下发数据 + 签名）
+     * - StrongBox 优先（硬件安全模块）
+     * - 不可导出
+     */
+    private void initKeyStore() {
+        try {
+            keyStore = KeyStore.getInstance(KEYSTORE_PROVIDER);
+            keyStore.load(null);
+
+            if (!keyStore.containsAlias(KEY_ALIAS)) {
+                generateTeeKeyPair();
+            }
+        } catch (Exception e) {
+            throw new RuntimeException("KeyStore init failed", e);
+        }
+    }
+
+    /**
+     * 在 TEE / StrongBox 中生成 RSA-2048 密钥对
+     */
+    private void generateTeeKeyPair() {
+        try {
+            KeyPairGenerator kpg = KeyPairGenerator.getInstance(
+                    KEY_ALGO, KEYSTORE_PROVIDER);
+
+            KeyGenParameterSpec spec = new KeyGenParameterSpec.Builder(
+                    KEY_ALIAS,
+                    KeyProperties.PURPOSE_DECRYPT |
+                    KeyProperties.PURPOSE_SIGN
+            )
+                    .setKeySize(RSA_KEY_SIZE)
+                    .setDigests(KeyProperties.DIGEST_SHA256)
+                    .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_RSA_OAEP)
+                    .setSignaturePaddings(KeyProperties.SIGNATURE_PADDING_RSA_PKCS1)
+                    .setUserAuthenticationRequired(false) // 无登录体系
+                    .setIsStrongBoxBacked(true)           // 优先 StrongBox
+                    .build();
+
+            kpg.initialize(spec);
+            kpg.generateKeyPair();
+        } catch (Exception e) {
+            throw new RuntimeException("TEE key gen failed", e);
+        }
+    }
+
+    // ==================== 公钥导出 ====================
+
+    /**
+     * 获取设备公钥（Base64 编码）
+     * 公钥可导出，用于：
+     * - 上传服务端存储
+     * - 服务端加密下发数据
+     */
+    public String getPublicKeyBase64() {
+        try {
+            KeyStore.PrivateKeyEntry entry =
+                    (KeyStore.PrivateKeyEntry) keyStore.getEntry(KEY_ALIAS, null);
+            PublicKey publicKey = entry.getCertificate().getPublicKey();
+            return Base64.getEncoder().encodeToString(publicKey.getEncoded());
+        } catch (Exception e) {
+            throw new RuntimeException("Get public key failed", e);
+        }
+    }
+
+    /**
+     * 获取设备 SN
+     * 实际实现：android.os.Build.getSerial()
+     */
+    public String getDeviceSN() {
+        // return android.os.Build.getSerial();
+        return "SN-DEMO-001";
+    }
+
+    // ==================== 数据信封加密 ====================
+
+    /**
+     * 加密敏感数据（如照片）
+     * 
+     * 流程：
+     * 1. 生成随机 AES-256 DEK
+     * 2. 生成随机 12 字节 IV
+     * 3. AES-256-GCM 加密数据
+     * 4. 返回密文 + IV + 明文DEK（DEK 由服务端用 UK 加密存储）
+     * 
+     * @return EncryptedPayload
+     */
+    public EncryptedPayload encryptData(byte[] plaintext) {
+        try {
+            // 1. 随机 DEK
+            KeyGenerator kg = KeyGenerator.getInstance("AES");
+            kg.init(AES_KEY_SIZE);
+            SecretKey dek = kg.generateKey();
+
+            // 2. 随机 IV
+            byte[] iv = new byte[GCM_IV_LENGTH];
+            java.security.SecureRandom random = new java.security.SecureRandom();
+            random.nextBytes(iv);
+
+            // 3. AES-256-GCM 加密
+            Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
+            GCMParameterSpec gcmSpec = new GCMParameterSpec(GCM_TAG_LENGTH, iv);
+            cipher.init(Cipher.ENCRYPT_MODE, dek, gcmSpec);
+            byte[] ciphertext = cipher.doFinal(plaintext);
+
+            return new EncryptedPayload(
+                    Base64.getEncoder().encodeToString(ciphertext),
+                    Base64.getEncoder().encodeToString(iv),
+                    Base64.getEncoder().encodeToString(dek.getEncoded())
+            );
+        } catch (Exception e) {
+            throw new RuntimeException("Encrypt failed", e);
+        }
+    }
+
+    // ==================== 元数据签名 ====================
+
+    /**
+     * 对元数据做 RSA 签名（防伪造、防篡改）
+     * 
+     * 签名内容示例："SN-xxx|timestamp|photoId"
+     * 服务端用设备公钥验签
+     */
+    public String signMetadata(String metadata) {
+        try {
+            KeyStore.PrivateKeyEntry entry =
+                    (KeyStore.PrivateKeyEntry) keyStore.getEntry(KEY_ALIAS, null);
+            PrivateKey privateKey = entry.getPrivateKey();
+
+            Signature sig = Signature.getInstance(SIGN_ALGO);
+            sig.initSign(privateKey);
+            sig.update(metadata.getBytes("UTF-8"));
+            byte[] signature = sig.sign();
+
+            return Base64.getEncoder().encodeToString(signature);
+        } catch (Exception e) {
+            throw new RuntimeException("Sign failed", e);
+        }
+    }
+
+    // ==================== 恢复流程 ====================
+
+    /**
+     * 恢复出厂后，服务端下发用新公钥加密的 Recovery Token
+     * 本方法用 TEE 私钥解密，获取 Token
+     * 
+     * @param encryptedToken 服务端用设备公钥加密的 Token
+     * @return 明文 Token（格式：userId|deviceId|timestamp|nonce）
+     */
+    public String decryptRecoveryToken(byte[] encryptedToken) {
+        try {
+            KeyStore.PrivateKeyEntry entry =
+                    (KeyStore.PrivateKeyEntry) keyStore.getEntry(KEY_ALIAS, null);
+            PrivateKey privateKey = entry.getPrivateKey();
+
+            Cipher cipher = Cipher.getInstance(RSA_TRANSFORM);
+            cipher.init(Cipher.DECRYPT_MODE, privateKey);
+            byte[] decrypted = cipher.doFinal(encryptedToken);
+
+            return new String(decrypted, "UTF-8");
+        } catch (Exception e) {
+            throw new RuntimeException("Decrypt recovery token failed", e);
+        }
+    }
+
+    /**
+     * 解密服务端下发的加密 DEK
+     * 恢复流程中，服务端用设备公钥加密每个照片的 DEK
+     * 
+     * @param encryptedDek 加密的 DEK（Base64）
+     * @return 明文 DEK 字节
+     */
+    public byte[] decryptDek(String encryptedDekBase64) {
+        try {
+            KeyStore.PrivateKeyEntry entry =
+                    (KeyStore.PrivateKeyEntry) keyStore.getEntry(KEY_ALIAS, null);
+            PrivateKey privateKey = entry.getPrivateKey();
+
+            Cipher cipher = Cipher.getInstance(RSA_TRANSFORM);
+            cipher.init(Cipher.DECRYPT_MODE, privateKey);
+            return cipher.doFinal(Base64.getDecoder().decode(encryptedDekBase64));
+        } catch (Exception e) {
+            throw new RuntimeException("Decrypt DEK failed", e);
+        }
+    }
+
+    /**
+     * 用解出的 DEK 解密照片
+     */
+    public byte[] decryptPhoto(String ciphertextBase64, String ivBase64, byte[] dekBytes) {
+        try {
+            SecretKey dek = new javax.crypto.spec.SecretKeySpec(dekBytes, "AES");
+            byte[] iv = Base64.getDecoder().decode(ivBase64);
+            byte[] ciphertext = Base64.getDecoder().decode(ciphertextBase64);
+
+            Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
+            GCMParameterSpec spec = new GCMParameterSpec(GCM_TAG_LENGTH, iv);
+            cipher.init(Cipher.DECRYPT_MODE, dek, spec);
+
+            return cipher.doFinal(ciphertext);
+        } catch (Exception e) {
+            throw new RuntimeException("Decrypt photo failed", e);
+        }
+    }
+
+    // ==================== 数据模型 ====================
+
+    /**
+     * 加密后的数据载体
+     */
+    public static class EncryptedPayload {
+        public final String ciphertextBase64;  // AES-GCM 密文
+        public final String ivBase64;          // GCM IV
+        public final String dekBase64;         // 明文 DEK（HTTPS 传输给服务端）
+
+        public EncryptedPayload(String ciphertextBase64, String ivBase64, String dekBase64) {
+            this.ciphertextBase64 = ciphertextBase64;
+            this.ivBase64 = ivBase64;
+            this.dekBase64 = dekBase64;
+        }
+    }
+
+    /**
+     * 设备注册请求体
+     */
+    public static class DeviceRegisterRequest {
+        public String sn;
+        public String publicKeyBase64;
+
+        public DeviceRegisterRequest(String sn, String publicKeyBase64) {
+            this.sn = sn;
+            this.publicKeyBase64 = publicKeyBase64;
+        }
+    }
+
+    /**
+     * 上传加密照片请求体
+     */
+    public static class UploadPhotoRequest {
+        public String sn;
+        public String photoId;
+        public String ciphertextBase64;
+        public String ivBase64;
+        public String dekBase64;
+        public String metadataSignature;
+        public String metadata;
+
+        public UploadPhotoRequest(String sn, String photoId, String ciphertextBase64,
+                                  String ivBase64, String dekBase64,
+                                  String metadataSignature, String metadata) {
+            this.sn = sn;
+            this.photoId = photoId;
+            this.ciphertextBase64 = ciphertextBase64;
+            this.ivBase64 = ivBase64;
+            this.dekBase64 = dekBase64;
+            this.metadataSignature = metadataSignature;
+            this.metadata = metadata;
+        }
+    }
+
+    /**
+     * 恢复请求体（用户已通过短信验证）
+     */
+    public static class RecoveryRequest {
+        public String sn;
+        public String userId;
+        public String smsCode;
+        public String newPublicKeyBase64;
+
+        public RecoveryRequest(String sn, String userId, String smsCode, String newPublicKeyBase64) {
+            this.sn = sn;
+            this.userId = userId;
+            this.smsCode = smsCode;
+            this.newPublicKeyBase64 = newPublicKeyBase64;
+        }
+    }
+}