C# RSA加密解密无长度限制

加密,采用分段的方式,无长度限制:

public string RsaEncrypt(string rawInput, string publicKey)
        {
            if (string.IsNullOrEmpty(rawInput))
            {
                return string.Empty;
            }

            if(string.IsNullOrWhiteSpace(publicKey))
            {
                throw new ArgumentException("Invalid Public Key");
            }

            using (var rsaProvider = new RSACryptoServiceProvider())
            {
                var inputBytes = Encoding.UTF8.GetBytes(rawInput);//有含义的字符串转化为字节流
                rsaProvider.FromXmlString(publicKey);//载入公钥
                int bufferSize = (rsaProvider.KeySize / 8) - 11;//单块最大长度
                var buffer = new byte[bufferSize];
                using (MemoryStream inputStream = new MemoryStream(inputBytes),
                     outputStream = new MemoryStream())
                {
                    while (true)
                    { //分段加密
                        int readSize = inputStream.Read(buffer, 0, bufferSize);
                        if (readSize <= 0)
                        {
                            break;
                        }

                        var temp = new byte[readSize];
                        Array.Copy(buffer, 0, temp, 0, readSize);
                        var encryptedBytes = rsaProvider.Encrypt(temp, false);
                        outputStream.Write(encryptedBytes, 0, encryptedBytes.Length);
                    }
                    return Convert.ToBase64String(outputStream.ToArray());//转化为字节流方便传输
                }
            }
        }

解密,必须对应:

public string RsaDecrypt(string encryptedInput, string privateKey)
        {
            if (string.IsNullOrEmpty(encryptedInput))
            {
                return string.Empty;
            }

            if (string.IsNullOrWhiteSpace(privateKey))
            {
                throw new ArgumentException("Invalid Private Key");
            }

            using (var rsaProvider = new RSACryptoServiceProvider())
            {
                var inputBytes = Convert.FromBase64String(encryptedInput);
                rsaProvider.FromXmlString(privateKey);
                int bufferSize = rsaProvider.KeySize / 8;
                var buffer = new byte[bufferSize];
                using (MemoryStream inputStream = new MemoryStream(inputBytes),
                     outputStream = new MemoryStream())
                {
                    while (true)
                    {
                        int readSize = inputStream.Read(buffer, 0, bufferSize);
                        if (readSize <= 0)
                        {
                            break;
                        }

                        var temp = new byte[readSize];
                        Array.Copy(buffer, 0, temp, 0, readSize);
                        var rawBytes = rsaProvider.Decrypt(temp, false);
                        outputStream.Write(rawBytes, 0, rawBytes.Length);
                    }
                    return Encoding.UTF8.GetString(outputStream.ToArray());
                }
            }
        }

 

posted @ 2018-01-03 09:25  都是城市惹的祸  阅读(1291)  评论(0)    收藏  举报