指定的填充模式对此算法无效 – c＃ – System.Security.Cryptography

对c＃来说很新，目前在解密长密码时遇到问题，错误是

指定的密钥不是此算法的有效大小

我知道这与加密密码位长度不受支持有关，但不确定如何建议允许这些更长密码的方法。

这是我的加密和解密

“cipherKey”：“0123456789abcdef”，“cipherVector”：“somereallycooliv”

using System; using System.Security.Cryptography; using System.IO; using System.Text; namespace DataApi { public class Encryption { private readonly IConfigurationService _configService; private const string _vector = "cipherVector"; private const string _key = "cipherKey"; public Encryption(IConfigurationService configService) { _configService = configService; } public string EncryptString(string text) { if(string.IsNullOrEmpty(text)) { return ""; } try { var key = Encoding.UTF8.GetBytes(_configService.Get(_key)); byte[] IV = Encoding.ASCII.GetBytes(_configService.Get(_vector)); using (var aesAlg = Aes.Create()) { using (var encryptor = aesAlg.CreateEncryptor(key, IV)) { using (var msEncrypt = new MemoryStream()) { using (var csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)) using (var swEncrypt = new StreamWriter(csEncrypt)) { swEncrypt.Write(text); } var decryptedContent = msEncrypt.ToArray(); var result = new byte[IV.Length + decryptedContent.Length]; Buffer.BlockCopy(IV, 0, result, 0, IV.Length); Buffer.BlockCopy(decryptedContent, 0, result, IV.Length, decryptedContent.Length); return Convert.ToBase64String(result); } } } } catch(Exception e) { Loggifer.Error("Unable to encrypt string: "+text , e ); throw e; } } public string DecryptString(string cipherText) { if(string.IsNullOrEmpty(cipherText)) { return ""; } try { var fullCipher = Convert.FromBase64String(cipherText); byte[] IV = Encoding.ASCII.GetBytes(_configService.Get(_vector)); var cipher = new byte[16]; Buffer.BlockCopy(fullCipher, 0, IV, 0, IV.Length); Buffer.BlockCopy(fullCipher, IV.Length, cipher, 0, IV.Length); var key = Encoding.UTF8.GetBytes(_configService.Get(_key)); using (var aesAlg = Aes.Create()) { using (var decryptor = aesAlg.CreateDecryptor(key, IV)) { string result; using (var msDecrypt = new MemoryStream(cipher)) { using (var csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)) { using (var srDecrypt = new StreamReader(csDecrypt)) { result = srDecrypt.ReadToEnd(); } } } return result; } } } catch (Exception e) { Loggifer.Error("Unable to decrypt string: "+cipherText , e ); throw e; } } } } 

Answer 1

函数public string DecryptString(string cipherText)中需要进行两处更改

  var cipher = new byte[fullCipher.Length - IV.Length]; 

和

  Buffer.BlockCopy(fullCipher, IV.Length, cipher, 0, fullCipher.Length - IV.Length);