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Problem Updating to .Net 6 - Encrypting String

I'm using a string Encryption/Decryption class similar to the one provided here as a solution.
This worked well for me in .Net 5.
Now I wanted to update my project to .Net 6.
When using .Net 6, the decrypted string does get cut off a certain point depending on the length of the input string.
▶️ To make it easy to debug/reproduce my issue, I created a public repro Repository here.
The encryption code is on purpose in a Standard 2.0 Project.
Referencing this project are both a .Net 6 as well as a .Net 5 Console project.
Both are calling the encryption methods with the exact same input of "12345678901234567890" with the path phrase of "nzv86ri4H2qYHqc&m6rL".
.Net 5 output: "12345678901234567890"
.Net 6 output: "1234567890123456"
The difference in length is 4.
I also looked at the breaking changes for .Net 6, but could not find something which guided me to a solution.
I'm glad for any suggestions regarding my issue, thanks!
Encryption Class
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 = 128;
// 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 = Generate128BitsOfRandomEntropy();
var ivStringBytes = Generate128BitsOfRandomEntropy();
var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))
{
var keyBytes = password.GetBytes(Keysize / 8);
using (var symmetricKey = Aes.Create())
{
symmetricKey.BlockSize = 128;
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] + [16 bytes of IV] + [n bytes of CipherText]
var cipherTextBytesWithSaltAndIv = Convert.FromBase64String(cipherText);
// Get the saltbytes by extracting the first 16 bytes from the supplied cipherText bytes.
var saltStringBytes = cipherTextBytesWithSaltAndIv.Take(Keysize / 8).ToArray();
// Get the IV bytes by extracting the next 16 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();
using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))
{
var keyBytes = password.GetBytes(Keysize / 8);
using (var symmetricKey = Aes.Create())
{
symmetricKey.BlockSize = 128;
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);
}
}
}
}
}
}
private static byte[] Generate128BitsOfRandomEntropy()
{
var randomBytes = new byte[16]; // 16 Bytes will give us 128 bits.
using (var rngCsp = RandomNumberGenerator.Create())
{
// Fill the array with cryptographically secure random bytes.
rngCsp.GetBytes(randomBytes);
}
return randomBytes;
}
}
Calling code
var input = "12345678901234567890";
var inputLength = input.Length;
var inputBytes = Encoding.UTF8.GetBytes(input);
var encrypted = StringCipher.Encrypt(input, "nzv86ri4H2qYHqc&m6rL");
var output = StringCipher.Decrypt(encrypted, "nzv86ri4H2qYHqc&m6rL");
var outputLength = output.Length;
var outputBytes = Encoding.UTF8.GetBytes(output);
var lengthDiff = inputLength - outputLength;

The reason is this breaking change:
DeflateStream, GZipStream, and CryptoStream diverged from typical
Stream.Read and Stream.ReadAsync behavior in two ways:
They didn't complete the read operation until either the buffer passed
to the read operation was completely filled or the end of the stream
was reached.
And the new behaviour is:
Starting in .NET 6, when Stream.Read or Stream.ReadAsync is called on
one of the affected stream types with a buffer of length N, the
operation completes when:
At least one byte has been read from the stream, or The underlying
stream they wrap returns 0 from a call to its read, indicating no more
data is available.
In your case you are affected because of this code in Decrypt method:
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);
}
You do not check how much bytes Read actually read and whether it read them all. You could get away with this in previous versions of .NET because as mentioned CryptoStream behaviour was different from other streams, and because your buffer length is enough to hold all data. However, this is no longer the case and you need to check it as you would do for other streams. Or even better - just use CopyTo:
using (var plainTextStream = new MemoryStream())
{
cryptoStream.CopyTo(plainTextStream);
var plainTextBytes = plainTextStream.ToArray();
return Encoding.UTF8.GetString(plainTextBytes, 0, plainTextBytes.Length);
}
Or even better as another answer suggests, since you decrypt UTF8 text:
using (var plainTextReader = new StreamReader(cryptoStream))
{
return plainTextReader.ReadToEnd();
}

I think your problem is in here:
var decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
From the Stream.Read docs:
An implementation is free to return fewer bytes than requested even if the end of the stream has not been reached.
So that single call to Read is not guaranteed to read all available bytes (up to plainTextBytes.Length) -- it's well within its rights to read a smaller number of bytes.
.NET 6 has many performance improvements, and I wouldn't be surprised if this was the sort of trade-off they'd make in the name of performance.
You'll have to be good, and keep calling Read until it returns 0, which indicates that there's no more data to return.
However, it's a lot easier to just use a StreamReader, which will also take care of the UTF-8 decoding for you.
return new StreamReader(cryptoStream).ReadToEnd();

I use these 2 extension methods in my .net6 project.
namespace WebApi.Utilities;
public static class StringUtil
{
static string key = "Mohammad-Komaei#Encrypt!keY#";
public static string Encrypt(this string text)
{
if (string.IsNullOrEmpty(key))
throw new ArgumentException("Key must have valid value.", nameof(key));
if (string.IsNullOrEmpty(text))
throw new ArgumentException("The text must have valid value.", nameof(text));
var buffer = Encoding.UTF8.GetBytes(text);
var hash = SHA512.Create();
var aesKey = new byte[24];
Buffer.BlockCopy(hash.ComputeHash(Encoding.UTF8.GetBytes(key)), 0, aesKey, 0, 24);
using (var aes = Aes.Create())
{
if (aes == null)
throw new ArgumentException("Parameter must not be null.", nameof(aes));
aes.Key = aesKey;
using (var encryptor = aes.CreateEncryptor(aes.Key, aes.IV))
using (var resultStream = new MemoryStream())
{
using (var aesStream = new CryptoStream(resultStream, encryptor, CryptoStreamMode.Write))
using (var plainStream = new MemoryStream(buffer))
{
plainStream.CopyTo(aesStream);
}
var result = resultStream.ToArray();
var combined = new byte[aes.IV.Length + result.Length];
Array.ConstrainedCopy(aes.IV, 0, combined, 0, aes.IV.Length);
Array.ConstrainedCopy(result, 0, combined, aes.IV.Length, result.Length);
return Convert.ToBase64String(combined);
}
}
}
public static string Decrypt(this string encryptedText)
{
if (string.IsNullOrEmpty(key))
throw new ArgumentException("Key must have valid value.", nameof(key));
if (string.IsNullOrEmpty(encryptedText))
throw new ArgumentException("The encrypted text must have valid value.", nameof(encryptedText));
var combined = Convert.FromBase64String(encryptedText);
var buffer = new byte[combined.Length];
var hash = SHA512.Create();
var aesKey = new byte[24];
Buffer.BlockCopy(hash.ComputeHash(Encoding.UTF8.GetBytes(key)), 0, aesKey, 0, 24);
using (var aes = Aes.Create())
{
if (aes == null)
throw new ArgumentException("Parameter must not be null.", nameof(aes));
aes.Key = aesKey;
var iv = new byte[aes.IV.Length];
var ciphertext = new byte[buffer.Length - iv.Length];
Array.ConstrainedCopy(combined, 0, iv, 0, iv.Length);
Array.ConstrainedCopy(combined, iv.Length, ciphertext, 0, ciphertext.Length);
aes.IV = iv;
using (var decryptor = aes.CreateDecryptor(aes.Key, aes.IV))
using (var resultStream = new MemoryStream())
{
using (var aesStream = new CryptoStream(resultStream, decryptor, CryptoStreamMode.Write))
using (var plainStream = new MemoryStream(ciphertext))
{
plainStream.CopyTo(aesStream);
}
return Encoding.UTF8.GetString(resultStream.ToArray());
}
}
}
}

After upgrading from .net 2.2 to 6 I was facing exactly the same issue. It does not read entire buffer - mostly reads only upto 16 bytes, so, just break it down in loop upto maximum of 16 bytes.
This code may help:
int totalRead = 0;
int maxRead = 16;
while (totalRead < plainTextBytes.Length)
{
var countLeft = plainTextBytes.Length - totalRead;
var count = countLeft < 16 ? countLeft : maxRead;
int bytesRead = cryptoStream.Read(plainTextBytes, totalRead, count);
totalRead += bytesRead;
if (bytesRead == 0) break;
}

How can i encrypt by postgres and decrypt by c#?

I encrypt password in postgres
and i want to decrypt it in c#, but two ways can not matching
.How can i do that?
private static byte[] TruncateHash(string key, int length)
{
SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();
// Hash the key.
byte[] keyBytes = System.Text.Encoding.Unicode.GetBytes(key);
byte[] hash = sha1.ComputeHash(keyBytes);
// Truncate or pad the hash.
Array.Resize(ref hash, length);
return hash;
}
public static string EncryptString(string plaintext, string Passphrase)
{
TripleDESCryptoServiceProvider tripleDes = new TripleDESCryptoServiceProvider();
// Initialize the crypto provider.
tripleDes.Key = TruncateHash(Passphrase, tripleDes.KeySize / 8);
tripleDes.IV = TruncateHash("", tripleDes.BlockSize / 8);
// Convert the plaintext string to a byte array.
byte[] plaintextBytes = System.Text.Encoding.Unicode.GetBytes(plaintext);
// Create the stream.
System.IO.MemoryStream ms = new System.IO.MemoryStream();
// Create the encoder to write to the stream.
CryptoStream encStream = new CryptoStream(ms, tripleDes.CreateEncryptor(), System.Security.Cryptography.CryptoStreamMode.Write);
// Use the crypto stream to write the byte array to the stream.
encStream.Write(plaintextBytes, 0, plaintextBytes.Length);
encStream.FlushFinalBlock();
// Convert the encrypted stream to a printable string.
return Convert.ToBase64String(ms.ToArray());
}
public static string DecryptString(string encryptedtext, string Passphrase)
{
TripleDESCryptoServiceProvider tripleDes = new TripleDESCryptoServiceProvider();
// Initialize the crypto provider.
tripleDes.Key = TruncateHash(Passphrase, tripleDes.KeySize / 8);
tripleDes.IV = TruncateHash("", tripleDes.BlockSize / 8);
// Convert the encrypted text string to a byte array.
byte[] encryptedBytes = Convert.FromBase64String(encryptedtext);
// Create the stream.
System.IO.MemoryStream ms = new System.IO.MemoryStream();
// Create the decoder to write to the stream.
CryptoStream decStream = new CryptoStream(ms, tripleDes.CreateDecryptor(), System.Security.Cryptography.CryptoStreamMode.Write);
// Use the crypto stream to write the byte array to the stream.
decStream.Write(encryptedBytes, 0, encryptedBytes.Length);
decStream.FlushFinalBlock();
// Convert the plaintext stream to a string.
return System.Text.Encoding.Unicode.GetString(ms.ToArray());
}
I found a way to encrypt in postgres using pgcrypto.
And below is encrypt and decrypt in postgres.
SELECT encode(encrypt_iv('ABCDE121212','Key123', '','3des'), 'base64');
select decrypt_iv(decode('jEI4V5q6h5/p12NRJm666g==','base64'),'Key123','','3des')
What's wrong in my code, c# and postgres can't not matching.
I want to keep c# code and change postgres code to matching

Source Url
Encrypt function:
public static String AES_encrypt(String input, string key, string Iv, int keyLength)
{
RijndaelManaged aes = new RijndaelManaged();
aes.KeySize = keyLength;
aes.BlockSize = 128;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
aes.Key = mkey(key,keyLength);
aes.IV = mkey(Iv,128);
var encrypt = aes.CreateEncryptor(aes.Key, aes.IV);
byte[] xBuff = null;
using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, encrypt, CryptoStreamMode.Write))
{
byte[] xXml = Encoding.UTF8.GetBytes(input);
cs.Write(xXml, 0, xXml.Length);
cs.FlushFinalBlock();
}
xBuff = ms.ToArray();
}
return Convert.ToBase64String(xBuff,Base64FormattingOptions.None);
}
Decrypt function:
public static String AES_decrypt(String Input, string key, string Iv, int keyLength)
{
try
{
RijndaelManaged aes = new RijndaelManaged();
aes.KeySize = keyLength;
aes.BlockSize = 128;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
aes.Key = mkey(key,keyLength);
aes.IV = mkey(Iv,128);
var decrypt = aes.CreateDecryptor();
byte[] encryptedStr = Convert.FromBase64String(Input);
string Plain_Text;
using (var ms = new MemoryStream(encryptedStr))
{
using (var cs = new CryptoStream(ms, decrypt, CryptoStreamMode.Read))
{
using (StreamReader reader = new StreamReader(cs))
{
Plain_Text = reader.ReadToEnd();
}
}
}
return Plain_Text;
}
catch (Exception ex)
{
return null;
}
}
Helper function:
private static byte[] mkey(string skey, int keyLength)
{
int length = keyLength / 8;
byte[] key = Encoding.UTF8.GetBytes(skey);
byte[] k = GenerateEmptyArray(length);
for (int i = 0; i < key.Length; i++)
{
//k[i % 16] = (byte)(k[i % 16] ^ key[i]);
k[i] = key[i];
if(i == length-1)
break;
}
return k;
}
Variables:
input = "Hello World"
key = "NBJ42RKQ2vQoYFZO"
Iv = "j1C83921vHExVhVp"
keyLength = 128
Info about variables:
input - string that is not encrypted or encrypted. If it's encrypted it will be in Base64 format
key - Any Unicode character that will match the AES key size(in this example it's 128). I have written a function that will extract the specific length of characters and add them to a byte array
Code:
public static string PasswordFixer(string skey,int keyLength)
{
int length = keyLength / 8;
byte[] key = Encoding.UTF8.GetBytes(skey);
byte[] k = GenerateEmptyArray(length);
for (int i = 0; i < key.Length; i++)
{
k[i] = key[i];
if(i == length-1)
break;
}
return Encoding.UTF8.GetString(k);
}
Iv - it's always 128bit long meaning 16bytes. you can ignore Iv if you want, in PostgreSQL if you planing to use `encrypt` function then you can ignore the Iv by hard coding like this `aes.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };`
keylength-
This is the AES key length in this example we use 128bit meaning 16 bytes. whatever the characters that you use as the Key need to match the length of 16 bytes.
PostgreSQL
The equivalent SQL statement for the encryption and decryption is this
encrypt_iv,decrypt_iv
select convert_from(decrypt_iv(decode(tbl1.encrypted,'base64')::bytea ,'NBJ42RKQ2vQoYFZO','j1C83921vHExVhVp', 'aes-cbc/pad:pkcs'), 'UTF-8') as decrypted,tbl1.encrypted from (select encode(encrypt_iv('Hello World', 'NBJ42RKQ2vQoYFZO','j1C83921vHExVhVp', 'aes-cbc/pad:pkcs'), 'base64') as encrypted) as tbl1
encrypt,decrypt
select convert_from(decrypt(decode(tbl1.encrypted,'base64')::bytea ,'NBJ42RKQ2vQoYFZO', 'aes-cbc/pad:pkcs'), 'UTF-8') as decrypted,tbl1.encrypted from (select encode(encrypt('Hello World', 'NBJ42RKQ2vQoYFZO', 'aes-cbc/pad:pkcs'), 'base64') as encrypted) as tbl1

length of data to decrypt is invalid rijndael c# sql

I am trying to encrypt / decrypt sensitive data such as SSN, the encryption process goes fine, saving in DB looks good too, retrieval looks good too, but when I am on the last step to decrypt the data I am getting error message: length of data to decrypt is invalid.
I created a SQL Server table for testing which has one column to hold the data, of varbinary type with size of 500.
This is how the data looks like in the table:
Now here is whole code in C# which is used to encrypt the data, insert in the db, get the last record (test) and decrypt. As I said the error happens on the last step in the decryption step:
Encryption Step
public byte[] EncryptStringToBytes(string plainText)
{
// Check arguments.
if (plainText == null || plainText.Length <= 0)
throw new ArgumentNullException("plainText");
byte[] encrypted;
// Create an RijndaelManaged object
// with the specified key and IV.
using (RijndaelManaged rijAlg = new RijndaelManaged())
{
rijAlg.Mode = CipherMode.CBC;
rijAlg.Padding = PaddingMode.PKCS7;
string keyStr = "cGFzc3dvcmQAAAAAAAAAAA==";
string ivStr = "cGFzc3dvcmQAAAAAAAAAAA==";
byte[] ivArr = Convert.FromBase64String(keyStr);
byte[] keyArr = Convert.FromBase64String(ivStr);
rijAlg.Key = keyArr;
rijAlg.KeySize = 256;
rijAlg.BlockSize = 128;
rijAlg.IV = ivArr;
// Create a decrytor to perform the stream transform.
ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);
// Create the streams used for encryption.
using (MemoryStream 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);
}
encrypted = msEncrypt.ToArray();
SaveData(encrypted);
}
}
}
// Return the encrypted bytes from the memory stream.
return encrypted;
}
Saving data to database
public void SaveData(byte[] cipherText) {
string queryStmt = "INSERT INTO TestSSN(SSN) VALUES(#Content)";
using (SqlConnection _con = new SqlConnection(ConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString))
using (SqlCommand _cmd = new SqlCommand(queryStmt, _con))
{
SqlParameter param = _cmd.Parameters.Add("#Content", SqlDbType.VarBinary);
param.Value = cipherText;
_con.Open();
_cmd.ExecuteNonQuery();
_con.Close();
}
GetSSNData(1); }
Getting data from database
public byte[] GetSSNData(int id)
{
byte[] cipherData = new byte[500];
string queryStmt = "SELECT SSN FROM TestSSN WHERE ID=7";
using (SqlConnection _con = new SqlConnection(ConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString))
using (SqlCommand _cmd = new SqlCommand(queryStmt, _con))
{
_con.Open();
SqlDataReader rdr = _cmd.ExecuteReader();
if (rdr.HasRows)
{
while (rdr.Read())
{
cipherData = Encoding.ASCII.GetBytes(rdr[0].ToString());
}
}
_con.Close();
}
string roundtrip = DecryptStringFromBytes(cipherData);
return cipherData;
}
Trying to decrypt the data(you will notice two different ways for decryption here, but I'll get the same message for both of them)
static string DecryptStringFromBytes(byte[] cipherText)
{
// Check arguments.
if (cipherText == null || cipherText.Length <= 0)
throw new ArgumentNullException("cipherText");
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
// Create an RijndaelManaged object
// with the specified key and IV.
using (RijndaelManaged rijAlg = new RijndaelManaged())
{
rijAlg.Mode = CipherMode.CBC;
rijAlg.Padding = PaddingMode.PKCS7;
string keyStr = "cGFzc3dvcmQAAAAAAAAAAA==";
string ivStr = "cGFzc3dvcmQAAAAAAAAAAA==";
byte[] ivArr = Convert.FromBase64String(keyStr);
byte[] keyArr = Convert.FromBase64String(ivStr);
rijAlg.Key = keyArr;
rijAlg.KeySize = 256;
rijAlg.BlockSize = 128;
rijAlg.IV = ivArr;
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);
byte[] decryptedText = decryptor.TransformFinalBlock(cipherText, 0, cipherText.Length);
string decrpyted = ASCIIEncoding.UTF8.GetString(decryptedText);
// 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))
{
// byte[] decryptedText = decryptor.TransformFinalBlock(cipherText, 0, cipherText.Length);
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
}
return plaintext;
}
Advices more then welcome, I've been battling with the decryption whole day.
Thanks, Laziale

Check the place where you read your data from DB:
cipherData = Encoding.ASCII.GetBytes(rdr[0].ToString());
If rdr[0] is a byte array I don't think that you will get the string of bytes, probably you will get "System.Byte[]". And if you will get "0xFFAA" - Encoding.ASCII.GetBytes will not give you a byte array with { 0xFF, 0xAA } data. You should use SqlDataReader.GetBytes to read this data.
Also I want to remind you that SSN is sensitive information. You should inform your users that you are going to save this information. If you need this information just to verify identity - you can use last 4 digits or hash. Please consider to not save SSN if you don't have real justification for this.

How is it possible that Rijndael returns different result from string and byte[]?

Here is my code, first with string:
byte[] concatBytes = Encoding.ASCII.GetBytes(key);
byte[] keyBytes = Encoding.ASCII.GetBytes(key);
for (int i = 0; i < 3; i++)
{
concatBytes = Encrypt(Encoding.ASCII.GetString(concatBytes), keyBytes);
//Console.WriteLine(Transform.Hexa(concatBytes));
}
public byte[] Encrypt(string plainText, byte[] key)
{
byte[] encrypted;
using (var rijndael = new RijndaelManaged())
{
rijndael.Mode = CipherMode.ECB;
rijndael.KeySize = 128;
rijndael.BlockSize = 128;
rijndael.Padding = PaddingMode.Zeros;
rijndael.Key = key;
//rijndael.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
ICryptoTransform transform = rijndael.CreateEncryptor(rijndael.Key, rijndael.IV);
using (var memoryStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write))
{
using (var streamWriter = new StreamWriter(cryptoStream))
{
streamWriter.Write(plainText);
}
encrypted = memoryStream.ToArray();
}
}
}
return encrypted;
}
If i change my method parameter plainText to byte[] than my results are completely different. What am i missing here? Also, we have different results using OpenSSL and Rijndael AES encryption. Any suggestions how i could fix this?

StreamWriter(Stream):
Initializes a new instance of the StreamWriter class for the specified stream by using UTF-8 encoding and the default buffer size.
Since you're using a different encoding (UTF-8 rather than ASCII), it's not surprising that you get different results.

File Decryption Error: Bad Data

I am having some trouble getting a asp.net C# file encryption / decryption process to work. I can get the file uploaded and ecrypted, but cannot get the decryption to work.
I get the error: Exception Details: System.Security.Cryptography.CryptographicException: Bad Data. on the decryption line:
byte[] KeyDecrypted = rsa.Decrypt(KeyEncrypted, false);
Here is my encrypt function:
private void EncryptFile(string inFile)
{
RijndaelManaged rjndl = new RijndaelManaged();
rjndl.KeySize = 256;
rjndl.BlockSize = 256;
rjndl.Mode = CipherMode.CBC;
ICryptoTransform transform = rjndl.CreateEncryptor();
byte[] keyEncrypted = rsa.Encrypt(rjndl.Key, false);
byte[] LenK = new byte[4];
byte[] LenIV = new byte[4];
int lKey = keyEncrypted.Length;
LenK = BitConverter.GetBytes(lKey);
int lIV = rjndl.IV.Length;
LenIV = BitConverter.GetBytes(lIV);
int startFileName = inFile.LastIndexOf("\\") + 1;
// Change the file's extension to ".enc"
string outFile = EncrFolder + inFile.Substring(startFileName, inFile.LastIndexOf(".") - startFileName) + ".enc";
lblDecryptFileName.Text = outFile;
using (FileStream outFs = new FileStream(outFile, FileMode.Create))
{
outFs.Write(LenK, 0, 4);
outFs.Write(LenIV, 0, 4);
outFs.Write(keyEncrypted, 0, lKey);
outFs.Write(rjndl.IV, 0, lIV);
using (CryptoStream outStreamEncrypted = new CryptoStream(outFs, transform, CryptoStreamMode.Write))
{
int count = 0;
int offset = 0;
int blockSizeBytes = rjndl.BlockSize / 8;
byte[] data = new byte[blockSizeBytes];
int bytesRead = 0;
using (FileStream inFs = new FileStream(inFile, FileMode.Open))
{
do
{
count = inFs.Read(data, 0, blockSizeBytes);
offset += count;
outStreamEncrypted.Write(data, 0, count);
bytesRead += blockSizeBytes;
}
while (count > 0);
inFs.Close();
}
outStreamEncrypted.FlushFinalBlock();
outStreamEncrypted.Close();
}
outFs.Close();
}
}
And here is the decrypt function where the error occurs.
private void DecryptFile(string inFile)
{
// Create instance of Rijndael for
// symetric decryption of the data.
RijndaelManaged rjndl = new RijndaelManaged();
rjndl.KeySize = 256;
rjndl.BlockSize = 256;
rjndl.Mode = CipherMode.CBC;
byte[] LenK = new byte[4];
byte[] LenIV = new byte[4];
string outFile = DecrFolder + inFile.Substring(0, inFile.LastIndexOf(".")) + ".txt";
using (FileStream inFs = new FileStream(EncrFolder + inFile, FileMode.Open))
{
inFs.Seek(0, SeekOrigin.Begin);
inFs.Seek(0, SeekOrigin.Begin);
inFs.Read(LenK, 0, 3);
inFs.Seek(4, SeekOrigin.Begin);
inFs.Read(LenIV, 0, 3);
int lenK = BitConverter.ToInt32(LenK, 0);
int lenIV = BitConverter.ToInt32(LenIV, 0);
int startC = lenK + lenIV + 8;
int lenC = (int)inFs.Length - startC;
// Create the byte arrays for
// the encrypted Rijndael key,
// the IV, and the cipher text.
byte[] KeyEncrypted = new byte[lenK];
byte[] IV = new byte[lenIV];
// Extract the key and IV
// starting from index 8
// after the length values.
inFs.Seek(8, SeekOrigin.Begin);
inFs.Read(KeyEncrypted, 0, lenK);
inFs.Seek(8 + lenK, SeekOrigin.Begin);
inFs.Read(IV, 0, lenIV);
Directory.CreateDirectory(DecrFolder);
byte[] KeyDecrypted = rsa.Decrypt(KeyEncrypted, false);
ICryptoTransform transform = rjndl.CreateDecryptor(KeyDecrypted, IV);
using (FileStream outFs = new FileStream(outFile, FileMode.Create))
{
int count = 0;
int offset = 0;
int blockSizeBytes = rjndl.BlockSize / 8;
byte[] data = new byte[blockSizeBytes];
inFs.Seek(startC, SeekOrigin.Begin);
using (CryptoStream outStreamDecrypted = new CryptoStream(outFs, transform, CryptoStreamMode.Write))
{
do
{
count = inFs.Read(data, 0, blockSizeBytes);
offset += count;
outStreamDecrypted.Write(data, 0, count);
}
while (count > 0);
outStreamDecrypted.FlushFinalBlock();
outStreamDecrypted.Close();
}
outFs.Close();
}
inFs.Close();
}
}
Any help on this would be great! I am not an RSA encryption expert and have been reading a lot of posts but still not able to come up with a solution.

I have finally figured this out. The code worked well in a desktop application when I tried it there. It just didn't work in the asp.net 4 web application I was trying to write. The issue was the RSA object wasn't persisted through the session. So, the RSA object was created okay. The file was encrypted okay. But when I went to decrypt the file the RSA object was not there. The error message of System.Security.Cryptography.CryptographicException: Bad Data is misleading as that wasn't really the issue, the data was fine.
So, when creating the key and the RSA object I used the following:
rsa = new RSACryptoServiceProvider(cspp);
Session["rsa"] = rsa;
Next, when the decryption function is called I added in:
if (rsa == null)
rsa = (RSACryptoServiceProvider)Session["rsa"];
Of course, there is a little more code around this also so catch if there is no key for the RSA session, but this is the high level solution for the issue I was having.
If anyone is looking for this let me know and I can share more of the code.