如何加密可能包含非 base 64 字符的字符串

Question

更新：问题是我！我犯了一个错误，否则两个 Cods（下面和 PS 的那个都是正确的）但是仍然感谢@Luke Park 的出色回答，我学到了一些新东西。

我不熟悉encryption/decryption算法，所以我在网上搜索发现这个class:

Encrypting & Decrypting a String in C#

代码是：（我在 Decrypt 方法中添加了一个 Try/Catch 以防密码错误 return "";）

using System;
using System.Text;
using System.Security.Cryptography;
using System.IO;
using System.Linq;

namespace EncryptStringSample
{
    public static class StringCipher
    {
        // This constant is used to determine the keysize of the encryption algorithm in bits.
        // We divide this by 8 within the code below to get the equivalent number of bytes.
        private const int Keysize = 256;

        // This constant determines the number of iterations for the password bytes generation function.
        private const int DerivationIterations = 1000;

        public static string Encrypt(string plainText, string passPhrase)
        {
            // Salt and IV is randomly generated each time, but is preprended to encrypted cipher text
            // so that the same Salt and IV values can be used when decrypting.  
            var saltStringBytes = Generate256BitsOfRandomEntropy();
            var ivStringBytes = Generate256BitsOfRandomEntropy();
            var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
            using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))
            {
                var keyBytes = password.GetBytes(Keysize / 8);
                using (var symmetricKey = new RijndaelManaged())
                {
                    symmetricKey.BlockSize = 256;
                    symmetricKey.Mode = CipherMode.CBC;
                    symmetricKey.Padding = PaddingMode.PKCS7;
                    using (var encryptor = symmetricKey.CreateEncryptor(keyBytes, ivStringBytes))
                    {
                        using (var memoryStream = new MemoryStream())
                        {
                            using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
                            {
                                cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
                                cryptoStream.FlushFinalBlock();
                                // Create the final bytes as a concatenation of the random salt bytes, the random iv bytes and the cipher bytes.
                                var cipherTextBytes = saltStringBytes;
                                cipherTextBytes = cipherTextBytes.Concat(ivStringBytes).ToArray();
                                cipherTextBytes = cipherTextBytes.Concat(memoryStream.ToArray()).ToArray();
                                memoryStream.Close();
                                cryptoStream.Close();
                                return Convert.ToBase64String(cipherTextBytes);
                            }
                        }
                    }
                }
            }
        }

    public static string Decrypt(string cipherText, string passPhrase)
    {
        // Get the complete stream of bytes that represent:
        // [32 bytes of Salt] + [32 bytes of IV] + [n bytes of CipherText]
        var cipherTextBytesWithSaltAndIv = Convert.FromBase64String(cipherText);
        // Get the saltbytes by extracting the first 32 bytes from the supplied cipherText bytes.
        var saltStringBytes = cipherTextBytesWithSaltAndIv.Take(Keysize / 8).ToArray();
        // Get the IV bytes by extracting the next 32 bytes from the supplied cipherText bytes.
        var ivStringBytes = cipherTextBytesWithSaltAndIv.Skip(Keysize / 8).Take(Keysize / 8).ToArray();
        // Get the actual cipher text bytes by removing the first 64 bytes from the cipherText string.
        var cipherTextBytes = cipherTextBytesWithSaltAndIv.Skip((Keysize / 8) * 2).Take(cipherTextBytesWithSaltAndIv.Length - ((Keysize / 8) * 2)).ToArray();
        try
        {
            using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))
            {
                var keyBytes = password.GetBytes(Keysize / 8);
                using (var symmetricKey = new RijndaelManaged())
                {
                    symmetricKey.BlockSize = 256;
                    symmetricKey.Mode = CipherMode.CBC;
                    symmetricKey.Padding = PaddingMode.PKCS7;
                    using (var decryptor = symmetricKey.CreateDecryptor(keyBytes, ivStringBytes))
                    {
                        using (var memoryStream = new MemoryStream(cipherTextBytes))
                        {
                            using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
                            {
                                var plainTextBytes = new byte[cipherTextBytes.Length];
                                var decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
                                memoryStream.Close();
                                cryptoStream.Close();
                                return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
                            }
                        }
                    }
                }
            }
        }
        catch (Exception)
        {
            return "";
        }
    }

        private static byte[] Generate256BitsOfRandomEntropy()
        {
            var randomBytes = new byte[32]; // 32 Bytes will give us 256 bits.
            using (var rngCsp = new RNGCryptoServiceProvider())
            {
                // Fill the array with cryptographically secure random bytes.
                rngCsp.GetBytes(randomBytes);
            }
            return randomBytes;
        }
    }
}

我在我的申请中这样使用 class：

string plaintext = "InsertedPasswordByUserToEncrypt";
string password = plaintext; // use its own password as encryption key
string encryptedstring = StringCipher.Encrypt(plaintext, password);

我喜欢 class 因为如果我用相同的数据重复最后一行，它会给我不同的加密结果。

但是现在，我发现如果一个字符串有除 base64 字符之外的任何字符，它会引发这个异常： “输入不是有效的 Base-64 字符串，因为它包含非 base-64 字符”我在网上搜索并找到了这个问题的许多答案。像这样：

The input is not a valid Base-64 string as it contains a non-base 64 character

How can I solver an "base64 invalid characters" error?

在所有这些问题中，答案都是一样的：

Remove non-base64 characters from your string!!!

但是如果我或我的应用程序用户想要插入这样的字符串怎么办：“A@S#D$?”或“CanYouGu3$$我？" 或 .... 要加密？

我的问题：

A1. 有什么方法可以解决上述 Class 问题（我在上面提到过）而不用替换或删除用户可能插入的任何字符加密？

A2.如果没有修复，那么还有什么好的方法呢？我可以使用什么方法它可以 encrypt/decrypt 任何包含任何字符的字符串。

PS：这段代码也很好，对现有的非 base64 字符没有任何问题（因为它也使用这种方法 Encoding.UTF8.GetBytes 来防止任何异常）：https://codereview.stackexchange.com/questions/14892/simplified-secure-encryption-of-a-string

感谢您的宝贵时间

Answer 1

将您的输入字符串转换为字节数组，然后将其转换为 base64。现在您的输入字符串是有效的 base64 并且仍然可以被加密。

byte[] data = Encoding.UTF8.GetBytes(inputString);
string b64 = Convert.ToBase64String(data);

您可能需要花一些时间来理解为什么需要 base64。加密算法对字节数组、原始数据而非字符串进行操作。

如何加密可能包含非 base 64 字符的字符串

How to encrypt strings that may have non-base 64 characters

.net

c#

encryption

base64

winforms