AES Android IOS H5 加密方案

前景：

1、本项目原有功能RSA客户端对敏感信息进行加密

2、本次漏洞说是服务端返回值有敏感信息，需要密文返回

3、最初只跟H5联调成功，后续APP联调失败(H5和APP的需求排期不一致)，没关注到通用性

方案：

本次方案不算完美，还是有被劫持篡改的风险，但基本https证书认证加持，风险相对较小

客户端本地存需要存三个值：

1、RSA公钥

2、随机生成16个字符

3、AES偏移量

java加密

安卓同服务端代码

@Slf4j
public class AESClientUtils {private static final String AES = "AES";private static final String STRING_FORMAT = "UTF-8";private static final String TRANSFORMATION = "AES/CBC/PKCS5Padding";//定义一个初始向量的值 AES偏移量，客户端和服务端保持统一值private static final String IV_STRING = "9999543210123666";/*** 加密** @param aesKey  AESkey* @param content 明文* @return 密文*/public static String encrypt(String aesKey, String content) {try {byte[] byteContent = content.getBytes(STRING_FORMAT);// 注意，为了能与 iOS 统一 这里的 key 不可以使用 KeyGenerator、SecureRandom、SecretKey 生成byte[] enCodeFormat = aesKey.getBytes();SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, AES);byte[] initParam = IV_STRING.getBytes();IvParameterSpec ivParameterSpec = new IvParameterSpec(initParam);// 指定加密的算法、工作模式和填充方式Cipher cipher = Cipher.getInstance(TRANSFORMATION);cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivParameterSpec);byte[] encryptedBytes = cipher.doFinal(byteContent);// 同样对加密后数据进行 base64 编码return Base64Utils.encode(encryptedBytes);} catch (Exception e) {log.error("AES Client 加密失败 content={},encodeRules={}", content, aesKey, e);return null;}}/*** 解密** @param aesKey  AESkey* @param content 密文* @return 解密后的明文*/public static String decrypt(String aesKey,String content) {try {Base64.Decoder decoder = Base64.getDecoder();byte[] encryptedBytes = decoder.decode(content);byte[] enCodeFormat = aesKey.getBytes();SecretKeySpec secretKey = new SecretKeySpec(enCodeFormat, AES);byte[] initParam = IV_STRING.getBytes();IvParameterSpec ivParameterSpec = new IvParameterSpec(initParam);Cipher cipher = Cipher.getInstance(TRANSFORMATION);cipher.init(Cipher.DECRYPT_MODE, secretKey, ivParameterSpec);byte[] result = cipher.doFinal(encryptedBytes);return new String(result, STRING_FORMAT);} catch (Exception e) {log.error("AES Client 解密失败 content={},encodeRules={}", content, aesKey, e);return null;}}}

H5解密

var iv = "9999543210123666";

        const ciphertext = response.data.info[ele]//保存本地的随机生成的16字节密钥const key = CryptoJS.enc.Utf8.parse(sessionStorage.getItem('key')) //AES的偏移量const iv = CryptoJS.enc.Utf8.parse('9999543210123666')// 解密const bytes = CryptoJS.AES.decrypt(ciphertext, key, {iv: iv,mode: CryptoJS.mode.CBC,padding: CryptoJS.pad.Pkcs7,})// 解密后，需要将解密后的字符串转成UTF-8格式response.data.info[ele] = bytes.toString(CryptoJS.enc.Utf8)

IOS解密

先定义一个初始向量的值

NSString *const kInitVector = @"9999543210123666"

确定密钥长度，这里选择 AES-128。

size_t const kKeySize = kCCKeySizeAES128

+ (NSString *)decryptAES:(NSString *)content key:(NSString *)key {// 把 base64 String 转换成 DataNSData *contentData = [[NSData alloc] initWithBase64EncodedString:content options:NSDataBase64DecodingIgnoreUnknownCharacters];NSUInteger dataLength = contentData.length;char keyPtr[kKeySize + 1];memset(keyPtr, 0, sizeof(keyPtr));[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];size_t decryptSize = dataLength + kCCBlockSizeAES128;void *decryptedBytes = malloc(decryptSize);size_t actualOutSize = 0;NSData *initVector = [kInitVector dataUsingEncoding:NSUTF8StringEncoding];CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,kCCAlgorithmAES,kCCOptionPKCS7Padding,keyPtr,kKeySize,initVector.bytes,contentData.bytes,dataLength,decryptedBytes,decryptSize,&actualOutSize);if (cryptStatus == kCCSuccess) {return [[NSString alloc] initWithData:[NSData dataWithBytesNoCopy:decryptedBytes length:actualOutSize] encoding:NSUTF8StringEncoding];}free(decryptedBytes);return nil;
}