使用.NET类的OpenSSL加密
问题描述：
我正在创建一个使用与OpenSSL兼容的.NET库的类。我知道有一个OpenSSL.Net包装，但我宁愿避免引用第三方\非托管代码。我不是在讨论这是否是正确的选择，但有理由。使用.NET类的OpenSSL加密
目前我有以下内容，我相信它应该与OpenSSL兼容 - 它有效地做到了OpenSSL从OpenSSL文档中做的事情。只是使用这个类做加密和解密。然而，即使，我发现了以下错误：
[CryptographicException] Padding is invalid and cannot be removed.
我已经通过代码加强，并验证了盐\键\ IV都是在同一加密和解密过程。
请参阅下面的示例类和呼叫做加密解密。任何想法或指针都会受到欢迎。
public class Protection
{
public string OpenSSLEncrypt(string plainText, string passphrase)
{
// generate salt
byte[] key, iv;
byte[] salt = new byte[8];
RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
rng.GetNonZeroBytes(salt);
DeriveKeyAndIV(passphrase, salt, out key, out iv);
// encrypt bytes
byte[] encryptedBytes = EncryptStringToBytesAes(plainText, key, iv);
// add salt as first 8 bytes
byte[] encryptedBytesWithSalt = new byte[salt.Length + encryptedBytes.Length];
Buffer.BlockCopy(salt, 0, encryptedBytesWithSalt, 0, salt.Length);
Buffer.BlockCopy(encryptedBytes, 0, encryptedBytesWithSalt, salt.Length, encryptedBytes.Length);
// base64 encode
return Convert.ToBase64String(encryptedBytesWithSalt);
}
public string OpenSSLDecrypt(string encrypted, string passphrase)
{
// base 64 decode
byte[] encryptedBytesWithSalt = Convert.FromBase64String(encrypted);
// extract salt (first 8 bytes of encrypted)
byte[] salt = new byte[8];
byte[] encryptedBytes = new byte[encryptedBytesWithSalt.Length - salt.Length];
Buffer.BlockCopy(encryptedBytesWithSalt, 0, salt, 0, salt.Length);
Buffer.BlockCopy(encryptedBytesWithSalt, salt.Length, encryptedBytes, 0, encryptedBytes.Length);
// get key and iv
byte[] key, iv;
DeriveKeyAndIV(passphrase, salt, out key, out iv);
return DecryptStringFromBytesAes(encryptedBytes, key, iv);
}
private static void DeriveKeyAndIV(string passphrase, byte[] salt, out byte[] key, out byte[] iv)
{
// generate key and iv
List<byte> concatenatedHashes = new List<byte>(48);
byte[] password = Encoding.UTF8.GetBytes(passphrase);
byte[] currentHash = new byte[0];
MD5 md5 = MD5.Create();
bool enoughBytesForKey = false;
// See http://www.openssl.org/docs/crypto/EVP_BytesToKey.html#KEY_DERIVATION_ALGORITHM
while (!enoughBytesForKey)
{
int preHashLength = currentHash.Length + password.Length + salt.Length;
byte[] preHash = new byte[preHashLength];
Buffer.BlockCopy(currentHash, 0, preHash, 0, currentHash.Length);
Buffer.BlockCopy(password, 0, preHash, currentHash.Length, password.Length);
Buffer.BlockCopy(salt, 0, preHash, currentHash.Length + password.Length, salt.Length);
currentHash = md5.ComputeHash(preHash);
concatenatedHashes.AddRange(currentHash);
if (concatenatedHashes.Count >= 48)
enoughBytesForKey = true;
}
key = new byte[32];
iv = new byte[16];
concatenatedHashes.CopyTo(0, key, 0, 32);
concatenatedHashes.CopyTo(32, iv, 0, 16);
md5.Clear();
md5 = null;
}
static byte[] EncryptStringToBytesAes(string plainText, byte[] key, byte[] iv)
{
// Check arguments.
if (plainText == null || plainText.Length <= 0)
throw new ArgumentNullException("plainText");
if (key == null || key.Length <= 0)
throw new ArgumentNullException("key");
if (iv == null || iv.Length <= 0)
throw new ArgumentNullException("iv");
// Declare the stream used to encrypt to an in memory
// array of bytes.
MemoryStream msEncrypt;
// Declare the RijndaelManaged object
// used to encrypt the data.
RijndaelManaged aesAlg = null;
try
{
// Create a RijndaelManaged object
// with the specified key and IV.
aesAlg = new RijndaelManaged { Key = key, IV = iv, Mode = CipherMode.CBC, KeySize = 256, BlockSize = 256 };
// Create an encryptor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
msEncrypt = new MemoryStream();
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
swEncrypt.Flush();
swEncrypt.Close();
}
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
// Return the encrypted bytes from the memory stream.
return msEncrypt.ToArray();
}
static string DecryptStringFromBytesAes(byte[] cipherText, byte[] key, byte[] iv)
{
// Check arguments.
if (cipherText == null || cipherText.Length <= 0)
throw new ArgumentNullException("cipherText");
if (key == null || key.Length <= 0)
throw new ArgumentNullException("key");
if (iv == null || iv.Length <= 0)
throw new ArgumentNullException("iv");
// Declare the RijndaelManaged object
// used to decrypt the data.
RijndaelManaged aesAlg = null;
// Declare the string used to hold
// the decrypted text.
string plaintext;
try
{
// Create a RijndaelManaged object
// with the specified key and IV.
aesAlg = new RijndaelManaged { Key = key, IV = iv, Mode = CipherMode.CBC, KeySize = 256, BlockSize = 256};
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for decryption.
using (MemoryStream msDecrypt = new MemoryStream(cipherText))
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
srDecrypt.Close();
}
}
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
return plaintext;
}
}
我再调用这个来测试它：
Protection protection = new Protection();
const string passphrase = "<passphrase>";
string encrypted = protection.OpenSSLEncrypt(jobid, passphrase);
string decrypted = protection.OpenSSLDecrypt(encrypted, passphrase);
答
终于想通这一个。如果有人需要在不使用openssl包装的情况下集成openssl和.NET，我会在这里分享结果。
1）我的原始代码（如问题中）的主要问题是，您必须在设置密钥或IV之前初始化RijndaelManaged实例上的BlockSize和KeySize。
2）我也有块大小设置为256时，它应该只有128
3）我的问题剩下来的事实，OpenSSL的看跌期权，并预计“Salted__”到盐的前追加前加密的字符串，然后base64编码它。 （我最初在openssl文档中看到了关于文件加密的问题，但是并没有认为它直接通过命令行来做到这一点 - 显然我错了!!还要注意S中盐的大小写！）
随着所有的想法，这是我的“固定”代码：
public class Protection
{
public string OpenSSLEncrypt(string plainText, string passphrase)
{
// generate salt
byte[] key, iv;
byte[] salt = new byte[8];
RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
rng.GetNonZeroBytes(salt);
DeriveKeyAndIV(passphrase, salt, out key, out iv);
// encrypt bytes
byte[] encryptedBytes = EncryptStringToBytesAes(plainText, key, iv);
// add salt as first 8 bytes
byte[] encryptedBytesWithSalt = new byte[salt.Length + encryptedBytes.Length + 8];
Buffer.BlockCopy(Encoding.ASCII.GetBytes("Salted__"), 0, encryptedBytesWithSalt, 0, 8);
Buffer.BlockCopy(salt, 0, encryptedBytesWithSalt, 8, salt.Length);
Buffer.BlockCopy(encryptedBytes, 0, encryptedBytesWithSalt, salt.Length + 8, encryptedBytes.Length);
// base64 encode
return Convert.ToBase64String(encryptedBytesWithSalt);
}
public string OpenSSLDecrypt(string encrypted, string passphrase)
{
// base 64 decode
byte[] encryptedBytesWithSalt = Convert.FromBase64String(encrypted);
// extract salt (first 8 bytes of encrypted)
byte[] salt = new byte[8];
byte[] encryptedBytes = new byte[encryptedBytesWithSalt.Length - salt.Length - 8];
Buffer.BlockCopy(encryptedBytesWithSalt, 8, salt, 0, salt.Length);
Buffer.BlockCopy(encryptedBytesWithSalt, salt.Length + 8, encryptedBytes, 0, encryptedBytes.Length);
// get key and iv
byte[] key, iv;
DeriveKeyAndIV(passphrase, salt, out key, out iv);
return DecryptStringFromBytesAes(encryptedBytes, key, iv);
}
private static void DeriveKeyAndIV(string passphrase, byte[] salt, out byte[] key, out byte[] iv)
{
// generate key and iv
List<byte> concatenatedHashes = new List<byte>(48);
byte[] password = Encoding.UTF8.GetBytes(passphrase);
byte[] currentHash = new byte[0];
MD5 md5 = MD5.Create();
bool enoughBytesForKey = false;
// See http://www.openssl.org/docs/crypto/EVP_BytesToKey.html#KEY_DERIVATION_ALGORITHM
while (!enoughBytesForKey)
{
int preHashLength = currentHash.Length + password.Length + salt.Length;
byte[] preHash = new byte[preHashLength];
Buffer.BlockCopy(currentHash, 0, preHash, 0, currentHash.Length);
Buffer.BlockCopy(password, 0, preHash, currentHash.Length, password.Length);
Buffer.BlockCopy(salt, 0, preHash, currentHash.Length + password.Length, salt.Length);
currentHash = md5.ComputeHash(preHash);
concatenatedHashes.AddRange(currentHash);
if (concatenatedHashes.Count >= 48)
enoughBytesForKey = true;
}
key = new byte[32];
iv = new byte[16];
concatenatedHashes.CopyTo(0, key, 0, 32);
concatenatedHashes.CopyTo(32, iv, 0, 16);
md5.Clear();
md5 = null;
}
static byte[] EncryptStringToBytesAes(string plainText, byte[] key, byte[] iv)
{
// Check arguments.
if (plainText == null || plainText.Length <= 0)
throw new ArgumentNullException("plainText");
if (key == null || key.Length <= 0)
throw new ArgumentNullException("key");
if (iv == null || iv.Length <= 0)
throw new ArgumentNullException("iv");
// Declare the stream used to encrypt to an in memory
// array of bytes.
MemoryStream msEncrypt;
// Declare the RijndaelManaged object
// used to encrypt the data.
RijndaelManaged aesAlg = null;
try
{
// Create a RijndaelManaged object
// with the specified key and IV.
aesAlg = new RijndaelManaged { Mode = CipherMode.CBC, KeySize = 256, BlockSize = 128, Key = key, IV = iv };
// Create an encryptor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
msEncrypt = new MemoryStream();
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
swEncrypt.Flush();
swEncrypt.Close();
}
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
// Return the encrypted bytes from the memory stream.
return msEncrypt.ToArray();
}
static string DecryptStringFromBytesAes(byte[] cipherText, byte[] key, byte[] iv)
{
// Check arguments.
if (cipherText == null || cipherText.Length <= 0)
throw new ArgumentNullException("cipherText");
if (key == null || key.Length <= 0)
throw new ArgumentNullException("key");
if (iv == null || iv.Length <= 0)
throw new ArgumentNullException("iv");
// Declare the RijndaelManaged object
// used to decrypt the data.
RijndaelManaged aesAlg = null;
// Declare the string used to hold
// the decrypted text.
string plaintext;
try
{
// Create a RijndaelManaged object
// with the specified key and IV.
aesAlg = new RijndaelManaged {Mode = CipherMode.CBC, KeySize = 256, BlockSize = 128, Key = key, IV = iv};
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for decryption.
using (MemoryStream msDecrypt = new MemoryStream(cipherText))
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
srDecrypt.Close();
}
}
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
return plaintext;
}
}
+0
嗨，你有等价的openssl命令行参数来做相反的任务吗？例如，我用你的代码加密一条消息，我应该用什么命令来从openssl解密？ – hardywang 2012-10-26 20:28:18
+1
用openssl解密的等价命令是'openssl enc -d -aes-256-cbc -a -in encrypted_file.txt> decrypted_file.txt' – 2016-02-11 15:08:42
+0
这是一个死链接！这是正确的：https：//www.openssl.org/docs/manmaster/man3/EVP_BytesToKey。html – balage 2016-11-10 18:16:34
答
怕有一个错误与此最新的代码问题，以及OpenSSLDecrypt结果：
Padding is invalid and cannot be removed.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for >more information about the error and where it originated in the code.
Exception Details: System.Security.Cryptography.CryptographicException: Padding is invalid and cannot be removed.
It occurs at the closen paren of this code:
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))" in 'static string DecryptStringFromBytesAes(byte[] cipherText, byte[] key, byte[] iv)
我不知道它这将很难从一台计算机上加密一个文本块，然后将其发送给另一个存储和解密。
如果您尝试实现AES，则块大小不正确，对于AES（块大小= 256），它是128位。我没有看到有关PKCS＃7填充的提及，我相信这是AES的OpenSSL默认设置。另外通常的做法是创建一个随机的iv加密并将其加入到加密的数据中。在解密时拉出iv并将其用于解密。 – zaph 2016-07-21 21:38:01
我需要实现相同的功能，但使用3DES。任何建议？我正在尝试实现它？ – Azimuth 2016-09-22 11:15:31