【簽名加解密】c# rsa 解密超過128報錯解決

分段解密

 

public string DecryptJava(string privateKeyJava, string data, string encoding = "UTF-8")
        {
            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            rsa.FromPrivateKeyJavaString(privateKeyJava);
            byte[] encryptData = Convert.FromBase64String(data);
            byte[] dencryContent = null;
            #region 分段解密
            if (encryptData == null || encryptData.Length <= 0)
            {
                throw new NotSupportedException();
            }

            int keySize = rsa.KeySize / 8;
            byte[] buffer = new byte[keySize];

            using (MemoryStream input = new MemoryStream(encryptData))
            using (MemoryStream output = new MemoryStream())
            {
                while (true)
                {
                    int readLine = input.Read(buffer, 0, keySize);
                    if (readLine <= 0)
                    {
                        break;
                    }
                    byte[] temp = new byte[readLine];
                    Array.Copy(buffer, 0, temp, 0, readLine);
                    byte[] decrypt = rsa.Decrypt(temp, false);
                    output.Write(decrypt, 0, decrypt.Length);
                }
                dencryContent = output.ToArray();
            }
            #endregion
            return Encoding.UTF8.GetString(dencryContent);
        }