鸿蒙原生开发实战|Native 加密与安全:NAPI + OpenSSL 构建全栈密文服务

前言

数据加密是应用安全的基石。在 HarmonyOS 应用中,ArkTS 层通过 cryptoFramework 提供了基础的加密能力,但当我们需要在 Native 层(C/C++)处理大量敏感数据------例如后台文件加密存储、配置凭据保护、端到端通信加密------直接在 Native 侧完成加解密可以避免跨边界搬运明文的性能损失,同时让加密逻辑与业务逻辑同层部署,降低安全攻面。

本文选择 方向 A:NAPI + libcrypto(OpenSSL 子集)密文处理 ,在 C++ 侧引入 OpenSSL 实现 AES-256-GCM 对称加解密、RSA-OAEP 非对称加解密、SHA-256 摘要、HMAC 消息认证码、PBKDF2 密钥派生五大安全原语,通过 NAPI 导出为 ArkTS 可调用的 CryptoService 模块。所有代码基于 HarmonyOS NEXT / API 12+ 编写,提供完整的可运行工程代码。


一、为什么要在 Native 层做加密

1.1 安全收益

方案 密钥存储位置 密文处理路径 跨边界次数
ArkTS 层加密 NAPI 传密钥 ArkTS → NAPI → 密文回 ArkTS 2 次
Native 层加密 C++ 内存管理 C++ 内部 0 次
硬件安全模块 TEE/SE 独立安全域 N/A

在 Native 层完成加密,敏感数据(明文 + 密钥)无需离开 Native 进程空间,极大地压缩了攻击面。

1.2 性能收益

OpenSSL 是经过数十亿设备验证的硬件加速密码库。ARMv8 平台利用 AES 指令集(AESE/AESMC)实现硬件级加解密,Native 层直接调用这些指令,比 JS/TS 层软实现快 5~10 倍

1.3 本文目标

构建一个可直接用于生产环境的 CryptoService NAPI 模块,提供:

API 能力 典型场景
sha256(data) 安全散列 文件完整性校验
hmac(key, data) 消息认证码 API 请求签名
aesEncrypt/Decrypt(key, iv, data) AES-256-GCM 文件/配置加密
rsaEncrypt/Decrypt(pubKey, data) RSA-OAEP 密钥交换
pbkdf2(password, salt, iterations) 密钥派生 口令加固

二、整体架构设计

模块分为三层:

复制代码
┌──────────────────────────────────────────────────────────┐
│                     ArkTS 调用层                         │
│   CryptoService.sha256(data)                             │
│   CryptoService.aesEncrypt(key, iv, plaintext)          │
│   CryptoService.rsaEncrypt(pubKeyPem, data)             │
│   CryptoService.pbkdf2(password, salt, iterations)      │
└──────────────────────┬───────────────────────────────────┘
                       │ NAPI 边界:napi_value 互转
┌──────────────────────▼───────────────────────────────────┐
│              NAPI 桥接层(crypto_napi.cpp)              │
│   napi_value ←→ uint8_t[] 互转                          │
│   Buffer/ArrayBuffer 零拷贝传递                         │
│   OpenSSL 错误码 → ArkTS Error 映射                     │
└──────────────────────┬───────────────────────────────────┘
                       │ 直接 C++ 函数调用
┌──────────────────────▼───────────────────────────────────┐
│            Native 加密引擎(crypto_core.h)              │
│   EVP_CIPHER_CTX / EVP_MD_CTX / EVP_PKEY               │
│   AES-256-GCM / RSA-OAEP / SHA-256 / HMAC / PBKDF2     │
│   OpenSSL 3.x EVP API 封装                              │
└──────────────────────────────────────────────────────────┘

2.1 密钥管理原则

  • 会话密钥 :C++ std::vector<uint8_t> 管理,使用后立即 OPENSSL_cleanse() 擦除
  • 持久密钥 :通过 PBKDF2 派生,存储在 ArkTS 层安全存储(ohos.security.huks
  • 公钥:PEM 格式从 ArkTS 传入,由 Native 解析并验证格式

三、工程配置

3.1 目录结构

复制代码
entry/src/main/cpp/
├── CMakeLists.txt
├── crypto_napi.cpp          # NAPI 桥接入口
├── crypto_napi.h            # NAPI 函数声明
├── crypto_core.h            # 加密引擎核心实现
├── crypto_core.cpp          # 加密引擎实现
└── types/libcrypto          # OpenSSL 头文件(交叉编译工具链自带)

3.2 CMakeLists.txt(完整版)

cmake 复制代码
cmake_minimum_required(VERSION 3.4.1)
project(crypto_demo)

set(NAPI_DIR ${OHOS_NATIVE_DIR}/napi)

# OpenSSL 库路径(HarmonyOS SDK 提供的交叉编译版本)
set(OPENSSL_ROOT_DIR ${OHOS_NATIVE_DIR}/sysroot/usr)
set(OPENSSL_INCLUDE_DIR ${OPENSSL_ROOT_DIR}/include)
set(OPENSSL_LIB_DIR ${OPENSSL_ROOT_DIR}/lib)

add_library(crypto_demo SHARED
    crypto_napi.cpp
    crypto_core.cpp
)

target_include_directories(crypto_demo PRIVATE
    ${NAPI_DIR}
    ${OPENSSL_INCLUDE_DIR}
    ${CMAKE_CURRENT_SOURCE_DIR}
)

target_link_directories(crypto_demo PRIVATE
    ${OPENSSL_LIB_DIR}
)

target_link_libraries(crypto_demo PRIVATE
    ${NAPI_DIR}/libnapi_ndk.z.so
    ssl
    crypto
    hilog_ndk.z.so
)

# NAPI 符号导出
set_target_properties(crypto_demo PROPERTIES
    LINK_FLAGS "-Wl,--gc-sections"
)

ohos_generate_napi_info(crypto_demo)

关键说明 :HarmonyOS NEXT SDK 已预置 OpenSSL 3.x 的交叉编译版本,路径为 ${OHOS_NATIVE_DIR}/sysroot/usr/lib/libcrypto.z.solibssl.z.so,开发者无需自行编译 OpenSSL。OHOS_NATIVE_DIR 在构建时由 IDE 自动注入。

3.3 oh-package.json5 中的 Native 声明

json5 复制代码
// entry/src/main/cpp/types/libcrypto/oh-package.json5
{
  "name": "libcrypto_demo.so",
  "types": "./index.d.ts"
}

3.4 NAPI 类型声明(index.d.ts)

typescript 复制代码
// entry/src/main/cpp/types/libcrypto/index.d.ts
export const sha256: (data: ArrayBuffer | Uint8Array) => string;
export const hmac: (key: Uint8Array, data: Uint8Array) => string;
export const aesEncrypt: (key: Uint8Array, iv: Uint8Array, data: Uint8Array) => Uint8Array;
export const aesDecrypt: (key: Uint8Array, iv: Uint8Array, ciphertext: Uint8Array) => Uint8Array;
export const rsaEncrypt: (pubKeyPem: string, data: Uint8Array) => Uint8Array;
export const rsaDecrypt: (privKeyPem: string, ciphertext: Uint8Array) => Uint8Array;
export const pbkdf2: (password: string, salt: Uint8Array, iterations: number, keyLen: number) => Uint8Array;

四、Native 加密引擎核心实现

4.1 通用辅助与安全管理

cpp 复制代码
// crypto_core.h
// HarmonyOS NEXT Native 加密引擎核心
// AES-256-GCM / RSA-OAEP / SHA-256 / HMAC / PBKDF2
// 基于 OpenSSL 3.x EVP API

#ifndef CRYPTO_CORE_H
#define CRYPTO_CORE_H

#include <string>
#include <vector>
#include <cstdint>
#include <cstring>
#include <stdexcept>
#include <sstream>
#include <iomanip>

#include <openssl/evp.h>
#include <openssl/rand.h>
#include <openssl/pem.h>
#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/hmac.h>
#include <openssl/kdf.h>

namespace crypto_core {

// ============================================================
// 安全内存管理
// ============================================================

class SecureBuffer {
public:
    static void cleanse(void* ptr, size_t len) noexcept {
        if (ptr && len) OPENSSL_cleanse(ptr, len);
    }

    static void cleanse(std::vector<uint8_t>& buf) noexcept {
        if (!buf.empty()) {
            OPENSSL_cleanse(buf.data(), buf.size());
        }
    }
};

// ============================================================
// 工具函数
// ============================================================

inline std::string bytesToHex(const uint8_t* data, size_t len) {
    std::ostringstream oss;
    oss << std::hex << std::setfill('0');
    for (size_t i = 0; i < len; ++i) {
        oss << std::setw(2) << static_cast<int>(data[i]);
    }
    return oss.str();
}

inline std::vector<uint8_t> hexToBytes(const std::string& hex) {
    if (hex.length() % 2 != 0) {
        throw std::invalid_argument("Hex string length must be even");
    }
    std::vector<uint8_t> bytes(hex.length() / 2);
    for (size_t i = 0; i < bytes.size(); ++i) {
        auto byteStr = hex.substr(i * 2, 2);
        bytes[i] = static_cast<uint8_t>(std::stoul(byteStr, nullptr, 16));
    }
    return bytes;
}

inline std::string getLastOpenSSLError() {
    std::ostringstream oss;
    unsigned long err;
    char buf[256];
    while ((err = ERR_get_error()) != 0) {
        ERR_error_string_n(err, buf, sizeof(buf));
        oss << buf << "; ";
    }
    return oss.str();
}

// ============================================================
// SHA-256 摘要
// ============================================================

inline std::string sha256(const uint8_t* data, size_t len) {
    EVP_MD_CTX* ctx = EVP_MD_CTX_new();
    if (!ctx) throw std::runtime_error("Failed to create EVP_MD_CTX");

    uint8_t hash[EVP_MAX_MD_SIZE];
    unsigned int hashLen = 0;

    if (EVP_DigestInit_ex(ctx, EVP_sha256(), nullptr) != 1 ||
        EVP_DigestUpdate(ctx, data, len) != 1 ||
        EVP_DigestFinal_ex(ctx, hash, &hashLen) != 1) {
        EVP_MD_CTX_free(ctx);
        throw std::runtime_error("SHA-256 failed: " + getLastOpenSSLError());
    }

    EVP_MD_CTX_free(ctx);
    return bytesToHex(hash, hashLen);
}

// ============================================================
// HMAC-SHA256 消息认证码
// ============================================================

inline std::string hmac(const uint8_t* key, size_t keyLen,
                         const uint8_t* data, size_t dataLen) {
    uint8_t result[EVP_MAX_MD_SIZE];
    unsigned int resultLen = 0;

    HMAC_CTX* ctx = HMAC_CTX_new();
    if (!ctx) throw std::runtime_error("Failed to create HMAC_CTX");

    if (HMAC_Init_ex(ctx, key, static_cast<int>(keyLen),
                     EVP_sha256(), nullptr) != 1 ||
        HMAC_Update(ctx, data, dataLen) != 1 ||
        HMAC_Final(ctx, result, &resultLen) != 1) {
        HMAC_CTX_free(ctx);
        throw std::runtime_error("HMAC failed: " + getLastOpenSSLError());
    }

    HMAC_CTX_free(ctx);
    return bytesToHex(result, resultLen);
}

// ============================================================
// AES-256-GCM 对称加解密
// ============================================================

// AES-256-GCM 加密
// 返回格式: nonce(12) + ciphertext + tag(16)
inline std::vector<uint8_t> aesEncrypt(const uint8_t* key, size_t keyLen,
                                        const uint8_t* iv, size_t ivLen,
                                        const uint8_t* plaintext, size_t plaintextLen) {
    if (keyLen != 32) throw std::invalid_argument("AES-256 requires 32-byte key");
    if (ivLen != 12) throw std::invalid_argument("GCM recommends 12-byte IV");

    EVP_CIPHER_CTX* ctx = EVP_CIPHER_CTX_new();
    if (!ctx) throw std::runtime_error("Failed to create EVP_CIPHER_CTX");

    // 初始化加密操作
    if (EVP_EncryptInit_ex(ctx, EVP_aes_256_gcm(), nullptr, nullptr, nullptr) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM init failed: " + getLastOpenSSLError());
    }

    // 设置 IV 长度(GCM 模式允许变长 IV,但 12 字节是推荐值)
    if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN,
                             static_cast<int>(ivLen), nullptr) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM set IV length failed: " + getLastOpenSSLError());
    }

    // 设置密钥和 IV
    if (EVP_EncryptInit_ex(ctx, nullptr, nullptr, key, iv) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM key/IV set failed: " + getLastOpenSSLError());
    }

    // 加密
    std::vector<uint8_t> ciphertext(plaintextLen + EVP_MAX_BLOCK_LENGTH);
    int outLen = 0;

    if (EVP_EncryptUpdate(ctx, ciphertext.data(), &outLen,
                           plaintext, static_cast<int>(plaintextLen)) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM encrypt failed: " + getLastOpenSSLError());
    }

    int totalLen = outLen;

    // 结束加密
    if (EVP_EncryptFinal_ex(ctx, ciphertext.data() + totalLen, &outLen) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM finalize failed: " + getLastOpenSSLError());
    }
    totalLen += outLen;

    // 获取认证标签(GCM Tag,16 字节)
    uint8_t tag[16];
    if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_GET_TAG, 16, tag) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM get tag failed: " + getLastOpenSSLError());
    }

    EVP_CIPHER_CTX_free(ctx);
    ciphertext.resize(totalLen);

    // 输出格式: IV(12) + ciphertext + tag(16)
    std::vector<uint8_t> result;
    result.reserve(ivLen + totalLen + 16);
    result.insert(result.end(), iv, iv + ivLen);
    result.insert(result.end(), ciphertext.begin(), ciphertext.end());
    result.insert(result.end(), tag, tag + 16);

    return result;
}

// AES-256-GCM 解密
// 输入格式: nonce(12) + ciphertext + tag(16)
inline std::vector<uint8_t> aesDecrypt(const uint8_t* key, size_t keyLen,
                                        const uint8_t* input, size_t inputLen) {
    if (keyLen != 32) throw std::invalid_argument("AES-256 requires 32-byte key");
    if (inputLen < 12 + 16) throw std::invalid_argument("Input too short (min 28 bytes)");

    const uint8_t* iv = input;
    size_t ivLen = 12;

    const uint8_t* ciphertext = input + 12;
    size_t ciphertextLen = inputLen - 12 - 16;

    const uint8_t* tag = input + inputLen - 16;

    EVP_CIPHER_CTX* ctx = EVP_CIPHER_CTX_new();
    if (!ctx) throw std::runtime_error("Failed to create EVP_CIPHER_CTX");

    if (EVP_DecryptInit_ex(ctx, EVP_aes_256_gcm(), nullptr, nullptr, nullptr) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM decrypt init failed: " + getLastOpenSSLError());
    }

    if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN,
                             static_cast<int>(ivLen), nullptr) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM set IV length failed: " + getLastOpenSSLError());
    }

    if (EVP_DecryptInit_ex(ctx, nullptr, nullptr, key, iv) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM key/IV set failed: " + getLastOpenSSLError());
    }

    std::vector<uint8_t> plaintext(ciphertextLen + EVP_MAX_BLOCK_LENGTH);
    int outLen = 0;

    if (EVP_DecryptUpdate(ctx, plaintext.data(), &outLen,
                           ciphertext, static_cast<int>(ciphertextLen)) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM decrypt update failed: " + getLastOpenSSLError());
    }

    int totalLen = outLen;

    // 设置期望的认证标签
    if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_TAG, 16,
                             const_cast<uint8_t*>(tag)) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM set tag failed: " + getLastOpenSSLError());
    }

    // 完成解密并验证认证标签
    if (EVP_DecryptFinal_ex(ctx, plaintext.data() + totalLen, &outLen) != 1) {
        EVP_CIPHER_CTX_free(ctx);
        throw std::runtime_error("AES-GCM authentication failed! Data may be tampered: "
                                 + getLastOpenSSLError());
    }
    totalLen += outLen;

    EVP_CIPHER_CTX_free(ctx);
    plaintext.resize(totalLen);

    return plaintext;
}

// ============================================================
// RSA-OAEP 非对称加解密
// ============================================================

// 加载 PEM 格式的公钥
inline EVP_PKEY* loadPublicKey(const std::string& pemData) {
    BIO* bio = BIO_new_mem_buf(pemData.data(),
                                static_cast<int>(pemData.size()));
    if (!bio) throw std::runtime_error("Failed to create BIO for public key");

    EVP_PKEY* pkey = PEM_read_bio_PUBKEY(bio, nullptr, nullptr, nullptr);
    BIO_free(bio);

    if (!pkey) {
        throw std::runtime_error("Failed to parse public key PEM: "
                                 + getLastOpenSSLError());
    }
    return pkey;
}

// 加载 PEM 格式的私钥
inline EVP_PKEY* loadPrivateKey(const std::string& pemData) {
    BIO* bio = BIO_new_mem_buf(pemData.data(),
                                static_cast<int>(pemData.size()));
    if (!bio) throw std::runtime_error("Failed to create BIO for private key");

    EVP_PKEY* pkey = PEM_read_bio_PrivateKey(bio, nullptr, nullptr, nullptr);
    BIO_free(bio);

    if (!pkey) {
        throw std::runtime_error("Failed to parse private key PEM: "
                                 + getLastOpenSSLError());
    }
    return pkey;
}

// RSA-OAEP 加密(使用 SHA-256 作为 OAEP 哈希)
inline std::vector<uint8_t> rsaEncrypt(const std::string& pubKeyPem,
                                        const uint8_t* data, size_t dataLen) {
    EVP_PKEY* pkey = loadPublicKey(pubKeyPem);

    EVP_PKEY_CTX* ctx = EVP_PKEY_CTX_new(pkey, nullptr);
    if (!ctx) {
        EVP_PKEY_free(pkey);
        throw std::runtime_error("Failed to create EVP_PKEY_CTX");
    }

    if (EVP_PKEY_encrypt_init(ctx) <= 0 ||
        EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_OAEP_PADDING) <= 0 ||
        EVP_PKEY_CTX_set_rsa_oaep_md(ctx, EVP_sha256()) <= 0 ||
        EVP_PKEY_CTX_set_rsa_mgf1_md(ctx, EVP_sha256()) <= 0) {
        EVP_PKEY_CTX_free(ctx);
        EVP_PKEY_free(pkey);
        throw std::runtime_error("RSA encrypt init failed: " + getLastOpenSSLError());
    }

    size_t outLen = 0;
    // 先获取输出长度
    if (EVP_PKEY_encrypt(ctx, nullptr, &outLen, data, dataLen) <= 0) {
        EVP_PKEY_CTX_free(ctx);
        EVP_PKEY_free(pkey);
        throw std::runtime_error("RSA encrypt length calc failed: " + getLastOpenSSLError());
    }

    std::vector<uint8_t> ciphertext(outLen);
    if (EVP_PKEY_encrypt(ctx, ciphertext.data(), &outLen, data, dataLen) <= 0) {
        EVP_PKEY_CTX_free(ctx);
        EVP_PKEY_free(pkey);
        throw std::runtime_error("RSA encrypt failed: " + getLastOpenSSLError());
    }

    EVP_PKEY_CTX_free(ctx);
    EVP_PKEY_free(pkey);
    ciphertext.resize(outLen);
    return ciphertext;
}

// RSA-OAEP 解密
inline std::vector<uint8_t> rsaDecrypt(const std::string& privKeyPem,
                                        const uint8_t* ciphertext, size_t ciphertextLen) {
    EVP_PKEY* pkey = loadPrivateKey(privKeyPem);

    EVP_PKEY_CTX* ctx = EVP_PKEY_CTX_new(pkey, nullptr);
    if (!ctx) {
        EVP_PKEY_free(pkey);
        throw std::runtime_error("Failed to create EVP_PKEY_CTX");
    }

    if (EVP_PKEY_decrypt_init(ctx) <= 0 ||
        EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_OAEP_PADDING) <= 0 ||
        EVP_PKEY_CTX_set_rsa_oaep_md(ctx, EVP_sha256()) <= 0 ||
        EVP_PKEY_CTX_set_rsa_mgf1_md(ctx, EVP_sha256()) <= 0) {
        EVP_PKEY_CTX_free(ctx);
        EVP_PKEY_free(pkey);
        throw std::runtime_error("RSA decrypt init failed: " + getLastOpenSSLError());
    }

    size_t outLen = 0;
    if (EVP_PKEY_decrypt(ctx, nullptr, &outLen, ciphertext, ciphertextLen) <= 0) {
        EVP_PKEY_CTX_free(ctx);
        EVP_PKEY_free(pkey);
        throw std::runtime_error("RSA decrypt length calc failed: " + getLastOpenSSLError());
    }

    std::vector<uint8_t> plaintext(outLen);
    if (EVP_PKEY_decrypt(ctx, plaintext.data(), &outLen, ciphertext, ciphertextLen) <= 0) {
        EVP_PKEY_CTX_free(ctx);
        EVP_PKEY_free(pkey);
        throw std::runtime_error("RSA decrypt failed: " + getLastOpenSSLError());
    }

    EVP_PKEY_CTX_free(ctx);
    EVP_PKEY_free(pkey);
    plaintext.resize(outLen);
    return plaintext;
}

// ============================================================
// PBKDF2 密钥派生
// ============================================================

inline std::vector<uint8_t> pbkdf2(const std::string& password,
                                    const uint8_t* salt, size_t saltLen,
                                    int iterations, int keyLen) {
    std::vector<uint8_t> derivedKey(keyLen);

    if (PKCS5_PBKDF2_HMAC(password.c_str(),
                            static_cast<int>(password.length()),
                            salt, static_cast<int>(saltLen),
                            iterations,
                            EVP_sha256(),
                            keyLen,
                            derivedKey.data()) != 1) {
        throw std::runtime_error("PBKDF2 failed: " + getLastOpenSSLError());
    }

    return derivedKey;
}

// ============================================================
// 随机数生成
// ============================================================

inline std::vector<uint8_t> randomBytes(size_t len) {
    std::vector<uint8_t> buf(len);
    if (RAND_bytes(buf.data(), static_cast<int>(len)) != 1) {
        throw std::runtime_error("RAND_bytes failed: " + getLastOpenSSLError());
    }
    return buf;
}

// ============================================================
// 安全密钥擦除
// ============================================================

inline void secureErase(std::vector<uint8_t>& buf) {
    cleanse(buf);
    buf.clear();
    buf.shrink_to_fit();
}

} // namespace crypto_core

#endif // CRYPTO_CORE_H

4.2 实现要点详解

AES-256-GCM

GCM(Galois/Counter Mode)同时提供加密和认证功能,是当前推荐的对称加密模式:

  • 密钥长度:256 位(32 字节)
  • IV 长度:推荐 12 字节(96 位),也是 OpenSSL 的默认值
  • Tag 长度:16 字节(128 位),提供最强的完整性保证
  • 输出格式IV(12) + ciphertext + tag(16),单次调用即可还原

每个加密操作生成唯一的随机 IV 并嵌入输出,解密时自动从输入提取------调用者无需额外管理 IV。

RSA-OAEP

OAEP(Optimal Asymmetric Encryption Padding)是 RSA 加密的标准填充方案:

  • 哈希函数:SHA-256(替代过时的 SHA-1)
  • MGF1:与主哈希一致的 SHA-256
  • 标签(Label):使用空标签(默认)
  • 适用数据量:最大为密钥长度 - 2 × hashLen - 2,2048 位 RSA 约 190 字节
PBKDF2

基于口令的密钥派生函数:

  • 伪随机函数:HMAC-SHA256
  • 迭代次数:推荐 600000 次以上(2026 年安全基线)
  • 盐值长度:16 字节(128 位)
  • 输出密钥长度:按需指定(AES-256 需要 32 字节)

五、NAPI 桥接层实现

5.1 crypto_napi.h

cpp 复制代码
// crypto_napi.h
#ifndef CRYPTO_NAPI_H
#define CRYPTO_NAPI_H

#include "napi/native_api.h"

// 模块初始化入口
napi_value CryptoModuleInit(napi_env env, napi_value exports);

// NAPI 函数声明
napi_value NapiSha256(napi_env env, napi_callback_info info);
napi_value NapiHmac(napi_env env, napi_callback_info info);
napi_value NapiAesEncrypt(napi_env env, napi_callback_info info);
napi_value NapiAesDecrypt(napi_env env, napi_callback_info info);
napi_value NapiRsaEncrypt(napi_env env, napi_callback_info info);
napi_value NapiRsaDecrypt(napi_env env, napi_callback_info info);
napi_value NapiPbkdf2(napi_env env, napi_callback_info info);
napi_value NapiRandomBytes(napi_env env, napi_callback_info info);

#endif

5.2 crypto_napi.cpp(完整实现)

cpp 复制代码
// crypto_napi.cpp
// HarmonyOS NEXT NAPI 加密模块桥接层
// OpenSSL 加密引擎 → ArkTS 可调用的 NAPI 函数

#include "crypto_napi.h"
#include "crypto_core.h"

#include <string>
#include <vector>
#include <cstdint>
#include <cstring>

#include <hilog/log.h>

#undef LOG_DOMAIN
#undef LOG_TAG
#define LOG_DOMAIN 0x0001
#define LOG_TAG "CryptoNative"

// ============================================================
// 辅助函数:NAPI ↔ C++ 类型转换
// ============================================================

// 将 NAPI Buffer/ArrayBuffer 转为 C++ vector<uint8_t>
static std::vector<uint8_t> GetBufferFromNapi(napi_env env,
                                               napi_value value) {
    bool isArrayBuffer = false;
    napi_is_arraybuffer(env, value, &isArrayBuffer);

    bool isTypedArray = false;
    napi_is_typedarray(env, value, &isTypedArray);

    void* data = nullptr;
    size_t length = 0;

    if (isArrayBuffer) {
        napi_get_arraybuffer_info(env, value, &data, &length);
    } else if (isTypedArray) {
        napi_typedarray_type type;
        napi_value buffer;
        size_t offset;
        napi_get_typedarray_info(env, value, &type, &length,
                                  &data, &buffer, &offset);
    } else {
        // 尝试从 Buffer 对象读取(兼容不同 API 版本)
        napi_value buf;
        napi_status status = napi_get_named_property(env, value, "buffer", &buf);
        if (status == napi_ok) {
            napi_get_arraybuffer_info(env, buf, &data, &length);
            // 调整 TypedArray 的 byteOffset
            napi_value byteOffset;
            napi_get_named_property(env, value, "byteOffset", &byteOffset);
            int64_t off = 0;
            napi_get_value_int64(env, byteOffset, &off);
            data = static_cast<uint8_t*>(data) + off;
        }
    }

    if (!data || length == 0) {
        return {};
    }

    std::vector<uint8_t> result(length);
    std::memcpy(result.data(), data, length);
    return result;
}

// 将 C++ vector<uint8_t> 转为 NAPI ArrayBuffer
static napi_value VectorToArrayBuffer(napi_env env,
                                       const std::vector<uint8_t>& data) {
    napi_value buffer;
    void* nativePtr = nullptr;
    napi_create_arraybuffer(env, data.size(), &nativePtr, &buffer);
    if (nativePtr && !data.empty()) {
        std::memcpy(nativePtr, data.data(), data.size());
    }
    return buffer;
}

// 将 C++ string 转为 NAPI string
static napi_value StringToNapi(napi_env env, const std::string& str) {
    napi_value result;
    napi_create_string_utf8(env, str.c_str(), str.length(), &result);
    return result;
}

// 解析 NAPI 参数并抛出类型错误
static napi_status ThrowTypeError(napi_env env, const char* msg) {
    napi_throw_type_error(env, nullptr, msg);
    return napi_invalid_arg;
}

// ============================================================
// NAPI 函数:sha256(data) → hex string
// ============================================================

napi_value NapiSha256(napi_env env, napi_callback_info info) {
    size_t argc = 1;
    napi_value argv[1];
    napi_get_cb_info(env, info, &argc, argv, nullptr, nullptr);

    if (argc < 1) {
        ThrowTypeError(env, "sha256: expected 1 argument (data: ArrayBuffer|Uint8Array)");
        return nullptr;
    }

    try {
        auto data = GetBufferFromNapi(env, argv[0]);
        std::string hash = crypto_core::sha256(data.data(), data.size());
        crypto_core::secureErase(data);
        return StringToNapi(env, hash);
    } catch (const std::exception& e) {
        OH_LOG_ERROR(LOG_APP, "sha256 error: %{public}s", e.what());
        napi_throw_error(env, nullptr, e.what());
        return nullptr;
    }
}

// ============================================================
// NAPI 函数:hmac(key, data) → hex string
// ============================================================

napi_value NapiHmac(napi_env env, napi_callback_info info) {
    size_t argc = 2;
    napi_value argv[2];
    napi_get_cb_info(env, info, &argc, argv, nullptr, nullptr);

    if (argc < 2) {
        ThrowTypeError(env, "hmac: expected 2 arguments (key, data)");
        return nullptr;
    }

    try {
        auto key = GetBufferFromNapi(env, argv[0]);
        auto data = GetBufferFromNapi(env, argv[1]);

        std::string result = crypto_core::hmac(key.data(), key.size(),
                                                data.data(), data.size());
        crypto_core::secureErase(key);
        return StringToNapi(env, result);
    } catch (const std::exception& e) {
        OH_LOG_ERROR(LOG_APP, "hmac error: %{public}s", e.what());
        napi_throw_error(env, nullptr, e.what());
        return nullptr;
    }
}

// ============================================================
// NAPI 函数:aesEncrypt(key, iv, data) → ArrayBuffer
// ============================================================

napi_value NapiAesEncrypt(napi_env env, napi_callback_info info) {
    size_t argc = 3;
    napi_value argv[3];
    napi_get_cb_info(env, info, &argc, argv, nullptr, nullptr);

    if (argc < 3) {
        ThrowTypeError(env, "aesEncrypt: expected 3 arguments (key, iv, data)");
        return nullptr;
    }

    try {
        auto key = GetBufferFromNapi(env, argv[0]);
        auto iv = GetBufferFromNapi(env, argv[1]);
        auto data = GetBufferFromNapi(env, argv[2]);

        auto ciphertext = crypto_core::aesEncrypt(
            key.data(), key.size(),
            iv.data(), iv.size(),
            data.data(), data.size());

        crypto_core::secureErase(key);
        return VectorToArrayBuffer(env, ciphertext);
    } catch (const std::exception& e) {
        OH_LOG_ERROR(LOG_APP, "aesEncrypt error: %{public}s", e.what());
        napi_throw_error(env, nullptr, e.what());
        return nullptr;
    }
}

// ============================================================
// NAPI 函数:aesDecrypt(key, iv, ciphertext) → ArrayBuffer
// ============================================================

napi_value NapiAesDecrypt(napi_env env, napi_callback_info info) {
    size_t argc = 3;
    napi_value argv[3];
    napi_get_cb_info(env, info, &argc, argv, nullptr, nullptr);

    if (argc < 3) {
        ThrowTypeError(env, "aesDecrypt: expected 3 arguments (key, iv, ciphertext)");
        return nullptr;
    }

    try {
        auto key = GetBufferFromNapi(env, argv[0]);
        auto ciphertext = GetBufferFromNapi(env, argv[1]);

        // 注意:aesDecrypt 的输入格式是 IV(12) + ciphertext + tag(16)
        // 但为了一致性,我们让 ArkTS 层传入 iv 和 ciphertext 分开,
        // 内部重新组装
        auto iv = GetBufferFromNapi(env, argv[1]);
        auto encData = GetBufferFromNapi(env, argv[2]);

        // 将 iv(12) + encData 重组为标准输入格式
        std::vector<uint8_t> combined;
        combined.reserve(iv.size() + encData.size());
        combined.insert(combined.end(), iv.begin(), iv.end());
        combined.insert(combined.end(), encData.begin(), encData.end());

        auto plaintext = crypto_core::aesDecrypt(
            key.data(), key.size(),
            combined.data(), combined.size());

        crypto_core::secureErase(key);
        return VectorToArrayBuffer(env, plaintext);
    } catch (const std::exception& e) {
        OH_LOG_ERROR(LOG_APP, "aesDecrypt error: %{public}s", e.what());
        napi_throw_error(env, nullptr, e.what());
        return nullptr;
    }
}

// ============================================================
// NAPI 函数:rsaEncrypt(pubKeyPem, data) → ArrayBuffer
// ============================================================

napi_value NapiRsaEncrypt(napi_env env, napi_callback_info info) {
    size_t argc = 2;
    napi_value argv[2];
    napi_get_cb_info(env, info, &argc, argv, nullptr, nullptr);

    if (argc < 2) {
        ThrowTypeError(env, "rsaEncrypt: expected 2 arguments (pubKeyPem, data)");
        return nullptr;
    }

    try {
        // 公钥 PEM 字符串
        char pemBuf[4096];
        size_t pemLen;
        napi_get_value_string_utf8(env, argv[0], pemBuf, sizeof(pemBuf), &pemLen);
        std::string pubKeyPem(pemBuf, pemLen);

        auto data = GetBufferFromNapi(env, argv[1]);
        auto ciphertext = crypto_core::rsaEncrypt(pubKeyPem, data.data(), data.size());

        return VectorToArrayBuffer(env, ciphertext);
    } catch (const std::exception& e) {
        OH_LOG_ERROR(LOG_APP, "rsaEncrypt error: %{public}s", e.what());
        napi_throw_error(env, nullptr, e.what());
        return nullptr;
    }
}

// ============================================================
// NAPI 函数:rsaDecrypt(privKeyPem, ciphertext) → ArrayBuffer
// ============================================================

napi_value NapiRsaDecrypt(napi_env env, napi_callback_info info) {
    size_t argc = 2;
    napi_value argv[2];
    napi_get_cb_info(env, info, &argc, argv, nullptr, nullptr);

    if (argc < 2) {
        ThrowTypeError(env, "rsaDecrypt: expected 2 arguments (privKeyPem, ciphertext)");
        return nullptr;
    }

    try {
        char pemBuf[8192];
        size_t pemLen;
        napi_get_value_string_utf8(env, argv[0], pemBuf, sizeof(pemBuf), &pemLen);
        std::string privKeyPem(pemBuf, pemLen);

        auto ciphertext = GetBufferFromNapi(env, argv[1]);
        auto plaintext = crypto_core::rsaDecrypt(privKeyPem,
                                                   ciphertext.data(),
                                                   ciphertext.size());

        return VectorToArrayBuffer(env, plaintext);
    } catch (const std::exception& e) {
        OH_LOG_ERROR(LOG_APP, "rsaDecrypt error: %{public}s", e.what());
        napi_throw_error(env, nullptr, e.what());
        return nullptr;
    }
}

// ============================================================
// NAPI 函数:pbkdf2(password, salt, iterations, keyLen) → ArrayBuffer
// ============================================================

napi_value NapiPbkdf2(napi_env env, napi_callback_info info) {
    size_t argc = 4;
    napi_value argv[4];
    napi_get_cb_info(env, info, &argc, argv, nullptr, nullptr);

    if (argc < 4) {
        ThrowTypeError(env,
            "pbkdf2: expected 4 arguments (password, salt, iterations, keyLen)");
        return nullptr;
    }

    try {
        char pwdBuf[1024];
        size_t pwdLen;
        napi_get_value_string_utf8(env, argv[0], pwdBuf, sizeof(pwdBuf), &pwdLen);
        std::string password(pwdBuf, pwdLen);

        auto salt = GetBufferFromNapi(env, argv[1]);

        int32_t iterations;
        napi_get_value_int32(env, argv[2], &iterations);

        int32_t keyLen;
        napi_get_value_int32(env, argv[3], &keyLen);

        auto derivedKey = crypto_core::pbkdf2(
            password, salt.data(), salt.size(), iterations, keyLen);

        // 擦除中间敏感数据
        volatile char* p = const_cast<char*>(pwdBuf);
        for (size_t i = 0; i < sizeof(pwdBuf); ++i) p[i] = 0;

        return VectorToArrayBuffer(env, derivedKey);
    } catch (const std::exception& e) {
        OH_LOG_ERROR(LOG_APP, "pbkdf2 error: %{public}s", e.what());
        napi_throw_error(env, nullptr, e.what());
        return nullptr;
    }
}

// ============================================================
// NAPI 函数:randomBytes(len) → ArrayBuffer
// ============================================================

napi_value NapiRandomBytes(napi_env env, napi_callback_info info) {
    size_t argc = 1;
    napi_value argv[1];
    napi_get_cb_info(env, info, &argc, argv, nullptr, nullptr);

    if (argc < 1) {
        ThrowTypeError(env, "randomBytes: expected 1 argument (len)");
        return nullptr;
    }

    try {
        int32_t len;
        napi_get_value_int32(env, argv[0], &len);
        if (len <= 0 || len > 1048576) {
            throw std::invalid_argument("randomBytes: len must be 1-1048576");
        }

        auto bytes = crypto_core::randomBytes(len);
        return VectorToArrayBuffer(env, bytes);
    } catch (const std::exception& e) {
        OH_LOG_ERROR(LOG_APP, "randomBytes error: %{public}s", e.what());
        napi_throw_error(env, nullptr, e.what());
        return nullptr;
    }
}

// ============================================================
// 模块初始化
// ============================================================

static napi_value Init(napi_env env, napi_value exports) {
    // 注册 NAPI 函数到 exports 对象
    napi_property_descriptor desc[] = {
        { "sha256",       nullptr, NapiSha256,       nullptr, nullptr, nullptr, napi_default, nullptr },
        { "hmac",         nullptr, NapiHmac,         nullptr, nullptr, nullptr, napi_default, nullptr },
        { "aesEncrypt",   nullptr, NapiAesEncrypt,   nullptr, nullptr, nullptr, napi_default, nullptr },
        { "aesDecrypt",   nullptr, NapiAesDecrypt,   nullptr, nullptr, nullptr, napi_default, nullptr },
        { "rsaEncrypt",   nullptr, NapiRsaEncrypt,   nullptr, nullptr, nullptr, napi_default, nullptr },
        { "rsaDecrypt",   nullptr, NapiRsaDecrypt,   nullptr, nullptr, nullptr, napi_default, nullptr },
        { "pbkdf2",       nullptr, NapiPbkdf2,       nullptr, nullptr, nullptr, napi_default, nullptr },
        { "randomBytes",  nullptr, NapiRandomBytes,  nullptr, nullptr, nullptr, napi_default, nullptr },
    };

    napi_define_properties(env, exports,
                           sizeof(desc) / sizeof(desc[0]), desc);
    return exports;
}

// NAPI 模块定义宏
NAPI_MODULE(crypto_demo, Init)

5.3 NAPI 桥接层设计要点

缓冲区零拷贝策略GetBufferFromNapi 优先使用 napi_get_typedarray_infonapi_get_arraybuffer_info 直接获取底层指针,避免不必要的内存拷贝。只有在跨 API 版本兼容场景下才回退到 property 路径。

安全擦除 :所有敏感数据(密钥、口令)在使用完毕后立即调用 OPENSSL_cleanse 擦除。注意 PBKDF2 的 password 缓冲区使用 volatile 阻止编译器优化。

错误传播 :OpenSSL 错误码通过 ERR_get_error 收集完整错误链,并通过 napi_throw_error 抛给 ArkTS 层,方便调试。


六、ArkTS 侧 CryptoService 封装

6.1 完整调用封装

typescript 复制代码
// entry/src/main/ets/service/CryptoService.ts
// CryptoService - Native 加密模块 ArkTS 封装层

import cryptoNative from 'libcrypto_demo.so';
import { hilog } from '@kit.PerformanceAnalysisKit';

const TAG = 'CryptoService';

export class CryptoService {
  /**
   * SHA-256 哈希摘要
   * @param data 输入数据
   * @returns 64 位十六进制哈希字符串
   */
  static sha256(data: Uint8Array | ArrayBuffer): string {
    try {
      const buffer = data instanceof ArrayBuffer ? data : data.buffer;
      return cryptoNative.sha256(buffer);
    } catch (err) {
      hilog.error(0x0001, TAG, `sha256 failed: ${err.message}`);
      throw new Error(`SHA-256 error: ${err.message}`);
    }
  }

  /**
   * HMAC-SHA256 消息认证码
   * @param key 密钥
   * @param data 待认证数据
   * @returns 64 位十六进制 HMAC 字符串
   */
  static hmac(key: Uint8Array, data: Uint8Array): string {
    try {
      return cryptoNative.hmac(key.buffer, data.buffer);
    } catch (err) {
      hilog.error(0x0001, TAG, `hmac failed: ${err.message}`);
      throw new Error(`HMAC error: ${err.message}`);
    }
  }

  /**
   * AES-256-GCM 加密
   * @param key 32 字节密钥
   * @param iv 12 字节初始向量
   * @param plaintext 明文数据
   * @returns 加密结果:IV(12) + ciphertext + tag(16)
   */
  static aesEncrypt(
    key: Uint8Array,
    iv: Uint8Array,
    plaintext: Uint8Array
  ): Uint8Array {
    try {
      const result = cryptoNative.aesEncrypt(key.buffer, iv.buffer, plaintext.buffer);
      return new Uint8Array(result);
    } catch (err) {
      hilog.error(0x0001, TAG, `aesEncrypt failed: ${err.message}`);
      throw new Error(`AES encrypt error: ${err.message}`);
    }
  }

  /**
   * AES-256-GCM 解密
   * @param key 32 字节密钥
   * @param iv 12 字节初始向量
   * @param ciphertext 加密数据(不含 iv 和 tag,为 aesEncrypt 返回值的 ciphertext 部分)
   */
  static aesDecrypt(
    key: Uint8Array,
    iv: Uint8Array,
    ciphertext: Uint8Array
  ): Uint8Array {
    try {
      const result = cryptoNative.aesDecrypt(key.buffer, iv.buffer, ciphertext.buffer);
      return new Uint8Array(result);
    } catch (err) {
      hilog.error(0x0001, TAG, `aesDecrypt failed: ${err.message}`);
      throw new Error(`AES decrypt error: ${err.message}`);
    }
  }

  /**
   * 便捷方法:一次调用完成加密(自动生成 IV)
   * @returns { iv, ciphertext },其中 ciphertext 含 tag
   */
  static aesEncryptAuto(key: Uint8Array, plaintext: Uint8Array): {
    iv: Uint8Array;
    ciphertext: Uint8Array;
  } {
    const iv = CryptoService.generateIV();
    const ciphertext = CryptoService.aesEncrypt(key, iv, plaintext);
    return { iv, ciphertext };
  }

  /**
   * RSA-OAEP 加密(使用 SHA-256)
   * @param pubKeyPem PEM 格式公钥
   * @param data 待加密数据(最大约 190 字节)
   * @returns 密文
   */
  static rsaEncrypt(pubKeyPem: string, data: Uint8Array): Uint8Array {
    try {
      const result = cryptoNative.rsaEncrypt(pubKeyPem, data.buffer);
      return new Uint8Array(result);
    } catch (err) {
      hilog.error(0x0001, TAG, `rsaEncrypt failed: ${err.message}`);
      throw new Error(`RSA encrypt error: ${err.message}`);
    }
  }

  /**
   * RSA-OAEP 解密
   * @param privKeyPem PEM 格式私钥
   * @param ciphertext 密文
   * @returns 明文
   */
  static rsaDecrypt(privKeyPem: string, ciphertext: Uint8Array): Uint8Array {
    try {
      const result = cryptoNative.rsaDecrypt(privKeyPem, ciphertext.buffer);
      return new Uint8Array(result);
    } catch (err) {
      hilog.error(0x0001, TAG, `rsaDecrypt failed: ${err.message}`);
      throw new Error(`RSA decrypt error: ${err.message}`);
    }
  }

  /**
   * PBKDF2 密钥派生
   * @param password 用户口令
   * @param salt 盐值(推荐 16 字节)
   * @param iterations 迭代次数(推荐 >= 600000)
   * @param keyLen 派生密钥长度(AES-256 需 32)
   * @returns 派生密钥
   */
  static pbkdf2(
    password: string,
    salt: Uint8Array,
    iterations: number,
    keyLen: number
  ): Uint8Array {
    try {
      const result = cryptoNative.pbkdf2(
        password,
        salt.buffer,
        iterations,
        keyLen
      );
      return new Uint8Array(result);
    } catch (err) {
      hilog.error(0x0001, TAG, `pbkdf2 failed: ${err.message}`);
      throw new Error(`PBKDF2 error: ${err.message}`);
    }
  }

  /**
   * 安全随机数生成
   * @param len 字节数
   * @returns 随机字节
   */
  static randomBytes(len: number): Uint8Array {
    try {
      const result = cryptoNative.randomBytes(len);
      return new Uint8Array(result);
    } catch (err) {
      hilog.error(0x0001, TAG, `randomBytes failed: ${err.message}`);
      throw new Error(`Random bytes error: ${err.message}`);
    }
  }

  /**
   * 便捷方法:生成随机 IV(AES-GCM 专用)
   */
  static generateIV(): Uint8Array {
    return CryptoService.randomBytes(12);
  }

  /**
   * 便捷方法:生成随机盐值(PBKDF2 专用)
   */
  static generateSalt(): Uint8Array {
    return CryptoService.randomBytes(16);
  }

  /**
   * 便捷方法:从口令派生 AES-256 密钥
   */
  static deriveAESKey(password: string, salt?: Uint8Array): {
    key: Uint8Array;
    salt: Uint8Array;
  } {
    const actualSalt = salt ?? CryptoService.generateSalt();
    const key = CryptoService.pbkdf2(password, actualSalt, 600000, 32);
    return { key, salt: actualSalt };
  }
}

6.2 文件加密管理器

typescript 复制代码
// entry/src/main/ets/service/FileEncryptor.ts
// 基于 CryptoService 的文件加密管理器

import { fileIo } from '@kit.CoreFileKit';
import { CryptoService } from './CryptoService';

const TAG = 'FileEncryptor';

export class FileEncryptor {
  private readonly password: string;

  constructor(password: string) {
    if (!password || password.length < 8) {
      throw new Error('Password must be at least 8 characters');
    }
    this.password = password;
  }

  /**
   * 加密整个文件
   */
  async encryptFile(sourcePath: string, outputPath: string): Promise<void> {
    // 1. 读取源文件
    const file = await fileIo.open(sourcePath, fileIo.OpenMode.READ_ONLY);
    const stat = await fileIo.stat(sourcePath);
    const buf = new Uint8Array(stat.size);
    await fileIo.read(file.fd, buf);
    fileIo.close(file);

    // 2. 派生 AES 密钥
    const { key, salt } = CryptoService.deriveAESKey(this.password);
    const iv = CryptoService.generateIV();

    // 3. AES 加密
    const encryptedData = CryptoService.aesEncrypt(key, iv, buf);

    // 4. 组装加密文件格式
    // [version(4) + saltLen(4) + salt + iv(12) + dataLen(4) + data]
    const meta = new ArrayBuffer(20);
    const metaView = new DataView(meta);
    metaView.setUint32(0, 1, true);     // version = 1
    metaView.setUint32(4, salt.byteLength, true);
    metaView.setUint32(8, 12, true);     // iv length
    metaView.setUint32(12, iv.byteLength, true);
    metaView.setUint32(16, encryptedData.byteLength, true);

    const outFile = await fileIo.open(outputPath, fileIo.OpenMode.CREATE);
    await fileIo.write(outFile.fd, new Uint8Array(meta));
    await fileIo.write(outFile.fd, salt);
    await fileIo.write(outFile.fd, iv);
    await fileIo.write(outFile.fd, encryptedData);
    fileIo.close(outFile);

    hilog.info(0x0001, TAG, `File encrypted: ${sourcePath} → ${outputPath}`);
  }

  /**
   * 解密整个文件
   */
  async decryptFile(sourcePath: string, outputPath: string): Promise<void> {
    const file = await fileIo.open(sourcePath, fileIo.OpenMode.READ_ONLY);

    // 读取元数据头
    const metaBuf = new Uint8Array(20);
    await fileIo.read(file.fd, metaBuf);
    const metaView = new DataView(metaBuf.buffer);
    const version = metaView.getUint32(0, true);
    if (version !== 1) {
      fileIo.close(file);
      throw new Error(`Unsupported file format version: ${version}`);
    }

    const saltLen = metaView.getUint32(4, true);
    const ivLen = metaView.getUint32(12, true);
    const dataLen = metaView.getUint32(16, true);

    // 读取盐值
    const salt = new Uint8Array(saltLen);
    await fileIo.read(file.fd, salt);

    // 读取 IV
    const iv = new Uint8Array(ivLen);
    await fileIo.read(file.fd, iv);

    // 读取加密数据
    const encryptedData = new Uint8Array(dataLen);
    await fileIo.read(file.fd, encryptedData);
    fileIo.close(file);

    // 派生密钥 + 解密
    const { key } = CryptoService.deriveAESKey(this.password, salt);
    const plaintext = CryptoService.aesDecrypt(key, iv, encryptedData);

    // 写入解密后的文件
    const outFile = await fileIo.open(outputPath, fileIo.OpenMode.CREATE);
    await fileIo.write(outFile.fd, plaintext);
    fileIo.close(outFile);

    hilog.info(0x0001, TAG, `File decrypted: ${sourcePath} → ${outputPath}`);
  }
}

七、加密应用配置示例

7.1 安全配置管理器

在实际应用中,经常需要将敏感配置(API Key、数据库密码、Token)加密存储。以下是完整的配置加密方案:

typescript 复制代码
// entry/src/main/ets/service/SecureConfig.ts
// 安全配置管理器

import { preferences } from '@kit.ArkData';
import { CryptoService } from './CryptoService';
import { fileIo } from '@kit.CoreFileKit';

const TAG = 'SecureConfig';
const CONFIG_FILE = 'secure_config.json.enc';
const PREFS_NAME = 'secure_config_prefs';

interface SecureConfigEntry {
  key: string;
  /** 加密后的值(hex 编码,便于存储) */
  encryptedValue: string;
  /** 使用的 IV(hex 编码) */
  iv: string;
}

export class SecureConfig {
  private configEntries: Map<string, SecureConfigEntry> = new Map();
  private masterKey: Uint8Array | null = null;
  private readonly context: Context;

  constructor(context: Context) {
    this.context = context;
  }

  /**
   * 初始化安全配置(从口令初始化主密钥)
   */
  async init(masterPassword: string): Promise<void> {
    // 尝试从持久化存储加载盐值
    const prefs = await preferences.getPreferences(this.context, PREFS_NAME);

    let saltHex = prefs.get('master_salt', '') as string;
    let salt: Uint8Array;

    if (!saltHex) {
      // 首次初始化,生成盐值并持久化
      salt = CryptoService.generateSalt();
      saltHex = Array.from(salt)
        .map(b => b.toString(16).padStart(2, '0'))
        .join('');
      await prefs.put('master_salt', saltHex);
      await prefs.flush();
    } else {
      salt = new Uint8Array(
        saltHex.match(/.{2}/g)!.map(h => parseInt(h, 16))
      );
    }

    // 派生主密钥(600000 次迭代)
    this.masterKey = CryptoService.pbkdf2(masterPassword, salt, 600000, 32);

    // 加载已保存的加密配置
    await this.loadEntries();
  }

  /**
   * 设置加密配置项
   */
  async set(key: string, value: string): Promise<void> {
    if (!this.masterKey) {
      throw new Error('SecureConfig not initialized. Call init() first.');
    }

    const iv = CryptoService.generateIV();
    const plaintext = new TextEncoder().encode(value);
    const { iv: _, ciphertext } = CryptoService.aesEncryptAuto(this.masterKey, plaintext);

    this.configEntries.set(key, {
      key,
      encryptedValue: this.bufferToHex(ciphertext),
      iv: this.bufferToHex(iv),
    });

    await this.saveEntries();
  }

  /**
   * 获取解密后的配置值
   */
  async get(key: string): Promise<string | null> {
    if (!this.masterKey) {
      throw new Error('SecureConfig not initialized.');
    }

    const entry = this.configEntries.get(key);
    if (!entry) return null;

    const iv = this.hexToBuffer(entry.iv);
    const encrypted = this.hexToBuffer(entry.encryptedValue);

    const decrypted = CryptoService.aesDecrypt(this.masterKey, iv, encrypted);
    return new TextDecoder().decode(decrypted);
  }

  /**
   * 删除配置项
   */
  async delete(key: string): Promise<void> {
    this.configEntries.delete(key);
    await this.saveEntries();
  }

  private async loadEntries(): Promise<void> {
    try {
      const filePath = `${this.context.filesDir}/${CONFIG_FILE}`;
      const file = await fileIo.open(filePath, fileIo.OpenMode.READ_ONLY);
      const stat = await fileIo.stat(filePath);
      const buf = new Uint8Array(stat.size);
      await fileIo.read(file.fd, buf);
      fileIo.close(file);

      // 校验 HMAC 完整性
      const storedHmac = new TextDecoder().decode(buf.slice(0, 64));
      const configData = buf.slice(64);

      const expectedHmac = CryptoService.hmac(this.masterKey!, new Uint8Array(configData));
      if (storedHmac !== expectedHmac) {
        throw new Error('Config file integrity check failed! Possible tampering.');
      }

      const json = new TextDecoder().decode(configData);
      const entries: SecureConfigEntry[] = JSON.parse(json);
      for (const entry of entries) {
        this.configEntries.set(entry.key, entry);
      }
    } catch (e) {
      // 文件不存在时忽略(首次使用)
      if ((e as Record<string, unknown>).code !== 'ENOENT') {
        hilog.warn(0x0001, TAG, `Load entries failed: ${(e as Error).message}`);
      }
    }
    hilog.info(0x0001, TAG, `Loaded ${this.configEntries.size} config entries`);
  }

  private async saveEntries(): Promise<void> {
    if (!this.masterKey) return;

    const entries = Array.from(this.configEntries.values());
    const json = JSON.stringify(entries);
    const configData = new TextEncoder().encode(json);

    // 生成 HMAC 完整性校验值
    const hmac = CryptoService.hmac(this.masterKey, new Uint8Array(configData));
    const fullData = new TextEncoder().encode(hmac + json);

    const filePath = `${this.context.filesDir}/${CONFIG_FILE}`;
    const file = await fileIo.open(
      filePath,
      fileIo.OpenMode.CREATE | fileIo.OpenMode.WRITE_ONLY
    );
    await fileIo.write(file.fd, fullData);
    fileIo.close(file);

    hilog.info(0x0001, TAG, `Saved ${entries.length} config entries`);
  }

  private bufferToHex(buf: Uint8Array): string {
    return Array.from(buf)
      .map(b => b.toString(16).padStart(2, '0'))
      .join('');
  }

  private hexToBuffer(hex: string): Uint8Array {
    const bytes = hex.match(/.{2}/g);
    if (!bytes) return new Uint8Array(0);
    return new Uint8Array(bytes.map(h => parseInt(h, 16)));
  }
}

7.2 页面中使用示例

typescript 复制代码
// entry/src/main/ets/pages/SecureSettings.ets
// 安全配置设置页面

import { CryptoService } from '../service/CryptoService';
import { SecureConfig } from '../service/SecureConfig';
import { FileEncryptor } from '../service/FileEncryptor';

@Entry
@Component
struct SecureSettings {
  @State masterPassword: string = '';
  @State apiKey: string = '';
  @State apiKeyDisplay: string = '******';
  @State statusText: string = '';
  @State hashResult: string = '';

  private secureConfig?: SecureConfig;
  private context: Context = getContext(this);

  aboutToAppear() {
    this.initializeCrypto();
  }

  async initializeCrypto() {
    this.statusText = '正在初始化加密引擎...';
    try {
      this.secureConfig = new SecureConfig(this.context);

      // 从安全存储获取主口令(生产环境应使用生物认证 + HUKS)
      const storedPassword = AppStorage.get<string>('master_password') ?? 'default-dev-pass';
      await this.secureConfig.init(storedPassword);

      this.statusText = '加密引擎就绪 ✓';
    } catch (err) {
      this.statusText = `初始化失败: ${(err as Error).message}`;
    }
  }

  build() {
    Column() {
      Text('安全配置管理').fontSize(24).fontWeight(FontWeight.Bold).margin(16)

      // 主口令输入
      TextInput({ placeholder: '输入主口令(至少 8 位)' })
        .type(InputType.Password)
        .onChange((val) => { this.masterPassword = val; })
        .margin(12)

      // SHA-256 演示
      Button('计算 SHA-256')
        .onClick(() => {
          const data = new TextEncoder().encode('Hello HarmonyOS Crypto');
          const hash = CryptoService.sha256(data);
          this.hashResult = hash;
        })
        .margin(12)
      if (this.hashResult) {
        Text(`SHA-256: ${this.hashResult}`).fontSize(12).fontColor(Color.Gray).margin(12)
      }

      // API Key 存储
      Row() {
        TextInput({ placeholder: '输入 API Key' })
          .type(InputType.Password)
          .onChange((val) => { this.apiKey = val; })
          .width('60%')

        Button('安全存储')
          .onClick(async () => {
            if (!this.secureConfig || !this.apiKey) return;
            await this.secureConfig.set('api_key', this.apiKey);
            this.statusText = 'API Key 已加密存储 ✓';
            this.apiKey = '';
          })
          .margin({ left: 8 })
      }.margin(12)

      Button('加载 API Key')
        .onClick(async () => {
          const key = await this.secureConfig?.get('api_key');
          this.apiKeyDisplay = key ?? '未设置';
          this.statusText = key ? '加载成功 ✓' : '未找到 API Key';
        })
        .margin(12)

      Text(`API Key: ${this.apiKeyDisplay}`)
        .fontSize(16)
        .margin(12)

      // 文件加密演示
      Button('加密示例文件')
        .onClick(async () => {
          try {
            const encryptor = new FileEncryptor(this.masterPassword || 'demo-password-123');
            const src = `${this.context.filesDir}/data.txt`;
            const dst = `${this.context.filesDir}/data.encrypted`;
            await encryptor.encryptFile(src, dst);
            this.statusText = '文件已加密 ✓';
          } catch (err) {
            this.statusText = `加密失败: ${(err as Error).message}`;
          }
        })
        .margin(12)

      Button('解密示例文件')
        .onClick(async () => {
          try {
            const encryptor = new FileEncryptor(this.masterPassword || 'demo-password-123');
            const src = `${this.context.filesDir}/data.encrypted`;
            const dst = `${this.context.filesDir}/data.decrypted`;
            await encryptor.decryptFile(src, dst);
            this.statusText = '文件已解密 ✓';
          } catch (err) {
            this.statusText = `解密失败: ${(err as Error).message}`;
          }
        })
        .margin(12)

      Text(this.statusText)
        .fontSize(14)
        .fontColor(Color.Gray)
        .margin(16)
    }
    .width('100%')
    .height('100%')
    .padding(16)
  }
}

7.3 RSA 密钥对生成与使用

typescript 复制代码
// entry/src/main/ets/util/RsaKeyUtil.ts
// RSA 密钥对工具(使用 HarmonyOS HUKS 生成密钥)

import { huks } from '@kit.CryptoArchitectureKit';
import { CryptoService } from '../service/CryptoService';

export class RsaKeyUtil {
  /**
   * 使用 HUKS 生成 RSA 2048 密钥对
   * 私钥由安全硬件保护,不可导出
   */
  static async generateKeyPair(keyAlias: string): Promise<void> {
    const properties: huks.HuksParam[] = [
      { tag: huks.HuksTag.HUKS_TAG_ALGORITHM, value: huks.HuksKeyAlg.HUKS_ALG_RSA },
      { tag: huks.HuksTag.HUKS_TAG_KEY_SIZE, value: huks.HuksKeySize.HUKS_RSA_KEY_SIZE_2048 },
      { tag: huks.HuksTag.HUKS_TAG_PURPOSE, value: huks.HuksKeyPurpose.HUKS_KEY_PURPOSE_ENCRYPT | huks.HuksKeyPurpose.HUKS_KEY_PURPOSE_DECRYPT },
      { tag: huks.HuksTag.HUKS_TAG_PADDING, value: huks.HuksKeyPadding.HUKS_PADDING_OAEP },
      { tag: huks.HuksTag.HUKS_TAG_DIGEST, value: huks.HuksKeyDigest.HUKS_DIGEST_SHA256 },
      { tag: huks.HuksTag.HUKS_TAG_BLOB_TYPE, value: huks.HuksKeyBlobType.HUKS_BLOB_TYPE_KEY },
    ];

    const options: huks.HuksOptions = {
      properties,
      purposeEnsureData: true,
    };

    await huks.generateKeyItem(keyAlias, options);
  }

  /**
   * 导出 RSA 公钥(PEM 格式)
   */
  static async exportPublicKey(keyAlias: string): Promise<string> {
    const pubKey = await huks.exportKeyItem(keyAlias);
    const keyData = pubKey.outData;

    // 转换为 PEM 格式
    const base64 = this.arrayBufferToBase64(keyData.buffer);
    const pem = [
      '-----BEGIN PUBLIC KEY-----',
      ...this.chunkString(base64, 64),
      '-----END PUBLIC KEY-----',
    ].join('\n');

    return pem;
  }

  /**
   * 使用 HUKS 保护的私钥解密
   */
  static async decryptWithHuks(keyAlias: string, ciphertext: Uint8Array): Promise<Uint8Array> {
    const options: huks.HuksOptions = {
      properties: [
        { tag: huks.HuksTag.HUKS_TAG_ALGORITHM, value: huks.HuksKeyAlg.HUKS_ALG_RSA },
        { tag: huks.HuksTag.HUKS_TAG_KEY_SIZE, value: huks.HuksKeySize.HUKS_RSA_KEY_SIZE_2048 },
        { tag: huks.HuksTag.HUKS_TAG_PURPOSE, value: huks.HuksKeyPurpose.HUKS_KEY_PURPOSE_DECRYPT },
        { tag: huks.HuksTag.HUKS_TAG_PADDING, value: huks.HuksKeyPadding.HUKS_PADDING_OAEP },
        { tag: huks.HuksTag.HUKS_TAG_DIGEST, value: huks.HuksKeyDigest.HUKS_DIGEST_SHA256 },
      ],
    };

    const result = await huks.initSession(keyAlias, options);
    const updateResult = await huks.updateSession(
      result.handle,
      options,
      ciphertext
    );
    const finishResult = await huks.finishSession(
      result.handle,
      options,
      updateResult.outData
    );

    const plaintext = new Uint8Array(finishResult.outData);
    return plaintext;
  }

  private static arrayBufferToBase64(buffer: ArrayBuffer): string {
    const bytes = new Uint8Array(buffer);
    let binary = '';
    for (let i = 0; i < bytes.byteLength; i++) {
      binary += String.fromCharCode(bytes[i]);
    }
    return btoa(binary);
  }

  private static chunkString(str: string, chunkSize: number): string[] {
    const chunks: string[] = [];
    for (let i = 0; i < str.length; i += chunkSize) {
      chunks.push(str.substring(i, i + chunkSize));
    }
    return chunks;
  }
}

八、性能测试与对比

8.1 基准测试

typescript 复制代码
// entry/src/main/ets/test/CryptoBenchmark.ets
// Native 加密性能基准测试

import { CryptoService } from '../service/CryptoService';

export async function runBenchmark(): Promise<BenchmarkResult[]> {
  const dataSizes = [64, 1024, 65536, 1048576]; // 64B, 1KB, 64KB, 1MB
  const iterations = 100;
  const results: BenchmarkResult[] = [];

  // 准备密钥
  const aesKey = CryptoService.randomBytes(32);
  const aesIv = CryptoService.randomBytes(12);

  // RSA 密钥
  const rsaPublicKey = `-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAvT9XHc5v3Z0Lx0Q0...
-----END PUBLIC KEY-----`;

  hilog.info(0x0001, 'Benchmark', '=== Crypto Performance Benchmark ===');

  for (const size of dataSizes) {
    const data = CryptoService.randomBytes(size);

    // SHA-256
    let start = performance.now();
    for (let i = 0; i < iterations; i++) {
      CryptoService.sha256(data);
    }
    const shaTime = (performance.now() - start) / iterations;

    // HMAC-SHA256
    start = performance.now();
    for (let i = 0; i < iterations; i++) {
      CryptoService.hmac(aesKey, data);
    }
    const hmacTime = (performance.now() - start) / iterations;

    // AES-256-GCM 加密
    start = performance.now();
    for (let i = 0; i < iterations; i++) {
      CryptoService.aesEncrypt(aesKey, aesIv, data);
    }
    const aesEncTime = (performance.now() - start) / iterations;

    // AES-256-GCM 解密
    const ciphertext = CryptoService.aesEncrypt(aesKey, aesIv, data);
    start = performance.now();
    for (let i = 0; i < iterations; i++) {
      CryptoService.aesDecrypt(aesKey, aesIv, ciphertext);
    }
    const aesDecTime = (performance.now() - start) / iterations;

    results.push({
      dataSize: size,
      sha256Ms: shaTime,
      hmacMs: hmacTime,
      aesEncryptMs: aesEncTime,
      aesDecryptMs: aesDecTime,
    });

    hilog.info(0x0001, 'Benchmark',
      `${size} bytes: SHA=${shaTime.toFixed(3)}ms ` +
      `HMAC=${hmacTime.toFixed(3)}ms ` +
      `AES-Enc=${aesEncTime.toFixed(3)}ms ` +
      `AES-Dec=${aesDecTime.toFixed(3)}ms`);
  }

  // RSA 测试
  const rsaData = new Uint8Array(32);
  for (let i = 0; i < 32; i++) rsaData[i] = i;

  let start = performance.now();
  for (let i = 0; i < 10; i++) {
    CryptoService.rsaEncrypt(rsaPublicKey, rsaData);
  }
  const rsaEncTime = (performance.now() - start) / 10;
  hilog.info(0x0001, 'Benchmark', `RSA-2048 OAEP Encrypt: ${rsaEncTime.toFixed(3)}ms`);

  return results;
}

interface BenchmarkResult {
  dataSize: number;
  sha256Ms: number;
  hmacMs: number;
  aesEncryptMs: number;
  aesDecryptMs: number;
}

8.2 预期性能数据

数据大小 SHA-256 HMAC-SHA256 AES-256-GCM 加密 AES-256-GCM 解密
64 B 0.002ms 0.003ms 0.008ms 0.009ms
1 KB 0.005ms 0.007ms 0.015ms 0.016ms
64 KB 0.052ms 0.068ms 0.082ms 0.087ms
1 MB 0.78ms 1.02ms 0.95ms 1.01ms

测试环境:HarmonyOS NEXT (API 12+),麒麟 9000 芯片,ARMv8 AES 指令集加速。数据为 100 次迭代平均值。


九、安全实践检查清单

✅ 密钥管理

实践 说明
使用 OPENSSL_cleanse 擦除密钥 编译器不会优化掉清零操作
避免密钥在 ArkTS 侧长期驻留 使用完后立即置零引用
PBKDF2 迭代次数 ≥ 600000 2026 年安全基线建议
每次加密使用唯一 IV GCM 模式 IV 复用会导致安全崩溃
RSA 密钥长度 ≥ 2048 推荐 4096 位

✅ 认证加密

  • 始终使用 AES-GCM(而非 AES-CBC + 独立 HMAC),避免"加密+认证"分离导致的实现错误
  • GCM Tag 验证失败时,绝不返回部分解密数据
  • 配置文件增加 HMAC 完整性校验,防止篡改

✅ 侧信道防护

  • 避免在错误信息中泄露密钥位数、明文长度等敏感信息
  • 使用常量时间比较(CRYPTO_memcmp)比较 MAC/Tag
  • PBKDF2 password 栈缓冲区使用 volatile 擦除

❌ 常见陷阱

typescript 复制代码
// ❌ 错误:IV 复用
const brokenIV = new Uint8Array(12); // 全零 IV,灾难
CryptoService.aesEncrypt(key, brokenIV, data1);
CryptoService.aesEncrypt(key, brokenIV, data2); // 攻击者可恢复密钥

// ✅ 正确:每次生成唯一 IV
const iv1 = CryptoService.generateIV();
CryptoService.aesEncrypt(key, iv1, data1);
const iv2 = CryptoService.generateIV();
CryptoService.aesEncrypt(key, iv2, data2);
typescript 复制代码
// ❌ 错误:ECB 模式(不应在任何场景使用)
// ECB 模式下,相同的明文块产生相同的密文块,泄露数据模式

// ✅ 正确:使用 GCM 认证加密
// AES-256-GCM 同时提供机密性、完整性、认证

十、总结

本文完整实现了一个基于 NAPI + OpenSSL 的 CryptoService 加密模块,涵盖 AES-256-GCM 对称加密、RSA-OAEP 非对称加密、SHA-256 摘要、HMAC 消息认证码和 PBKDF2 密钥派生五大安全原语,并通过 ArkTS 封装提供了简洁的调用接口。

核心收获

  1. HarmonyOS NEXT SDK 已内置 OpenSSL :无需额外交叉编译,target_link_libraries 中声明 cryptossl 即可
  2. Native 加密性能显著优于 ArkTS 层 :利用 ARMv8 AES 硬件指令,大数据场景可达 5~8x 加速
  3. 完整的安全生命周期:从密钥生成、使用到擦除,全程由 C++ 层管理,敏感数据无需离开 Native 进程空间
  4. 生产就绪的错误处理:OpenSSL 错误链通过 NAPI 完整传播到 ArkTS,hilog 记录完整的调试信息

扩展方向

  • HUKS 集成:将主密钥委托给 HarmonyOS Universal KeyStore 硬件安全模块,私钥由安全芯片保护
  • 上下文复用EVP_EncryptInit_ex 上下文在批量加密场景下复用,进一步降低高频调用开销
  • 文件分块加密:支持超大文件(>2GB)的分块加密,流式处理不占内存
  • XChaCha20-Poly1305:现代流式加密算法,在缺少 AES 硬件加速的平台上表现更佳
  • 量子安全预备:引入 Kyber/SPHINCS+ 后量子密码算法,为未来威胁做准备

附录:完整文件清单

复制代码
entry/src/main/cpp/
├── CMakeLists.txt                                # 构建配置(链接 libcrypto)
├── crypto_core.h                                 # 加密引擎核心(~320 行)
├── crypto_napi.h                                 # NAPI 函数声明
├── crypto_napi.cpp                               # NAPI 桥接实现(~350 行)
└── types/libcrypto/
    ├── index.d.ts                                # TypeScript 类型声明
    └── oh-package.json5                          # Native 包配置

entry/src/main/ets/
└── service/
    ├── CryptoService.ts                          # ArkTS 封装层
    ├── FileEncryptor.ts                          # 文件加密管理器
    ├── SecureConfig.ts                           # 安全配置管理器
    └── util/
        └── RsaKeyUtil.ts                         # RSA 密钥工具(HUKS 集成)

entry/src/main/ets/
└── pages/
    └── SecureSettings.ets                        # 安全设置 UI 示例

entry/src/main/ets/
└── test/
    └── CryptoBenchmark.ets                       # 性能基准测试
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