Has anyone else out there noticed that cryptostreams get truncated if
you follow the msdn method for encrypting and decrypting files/memory
streams? If I replace the crypto stream with a file stream in my code
everything works great, as soon as I put the crypto stream back in, it
gets truncated at some point. Does anyone know why or how to fix it?

Here is the code I'm using....

DataRow dr = dsBurgers.Tables["tblBurgers"].NewRow();
dr["burgerType"] = "cheeseBurgerffdfd";
dr["burgerPrice"] = 1.25;
dsBurgers.Tables["tblBurgers"].Rows.Add(dr);

//create key and initialization vector
byte[] rijnKey = {bla bla};
byte[] rijnIV = {bla bla};

dsBurgers.WriteXml("XmlDirect.txt");

//encode to file
FileStream fin = new
FileStream("XmlDirect.txt",FileMode.Open,FileAccess.Read);
FileStream fout = new
FileStream("XmlEnc.txt",FileMode.OpenOrCreate,FileAccess.Write);
fout.SetLength(0);
TripleDESCryptoServiceProvider rijn = new
TripleDESCryptoServiceProvider();
CryptoStream encStream = new
CryptoStream(fout,rijn.CreateEncryptor(rijnKey,rijnIV),CryptoStreamMode.Write);
long fileLength = fin.Length;
byte[] buffer = new Byte[1];
int amountRead = 0;
long amountDone = 0;
while(amountDone<fileLength)
{
amountRead = fin.Read(buffer,0,1);
encStream.Write(buffer,0,amountRead);
amountDone = amountDone + amountRead;
}
//fin.Read(buffer,0,Convert.ToInt32(fileLength));
//encStream.Write(buffer,0,Convert.ToInt32(fileLength));
fout.Close();
fin.Close();


//decrypt the file and make sure everything is still there
FileStream fin2 = new
FileStream("XmlEnc.txt",FileMode.Open,FileAccess.Read);
FileStream fout2 = new
FileStream("XmlOutEncDec.txt",FileMode.OpenOrCreate,FileAccess.Write);
fout2.SetLength(0);
CryptoStream decStream = new
CryptoStream(fout2,rijn.CreateDecryptor(rijnKey,rijnIV),CryptoStreamMode.Write);
long fileLen = fin2.Length;
amountRead = 0;
amountDone = 0;
while(amountDone<fileLen)
{
amountRead = fin2.Read(buffer,0,1);
decStream.Write(buffer,0,amountRead);
amountDone += amountRead;
}

//fin2.Read(buffer,0,Convert.ToInt32(fileLen));
//decStream.Write(buffer,0,Convert.ToInt32(fileLen));

fin2.Close();
fout2.Close();

___________________________________
changing encStream or decStream to fout and fout2 fixes everything,
which makes me think it could be a problem with the cryptostreams
themselves or there is something I don't know about their behavior
that would cause the truncation.

If anyone knows the answer please help.
Thanks and code on!
Matt

I think you may need to add a encStream.Flush() before you close your
underlying stream. This will clear any internal buffers the Crypto object
may be using.

Bill.


"Matt" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Has anyone else out there noticed that cryptostreams get truncated if
> you follow the msdn method for encrypting and decrypting files/memory
> streams? If I replace the crypto stream with a file stream in my code
> everything works great, as soon as I put the crypto stream back in, it
> gets truncated at some point. Does anyone know why or how to fix it?
>
> Here is the code I'm using....
>
> DataRow dr = dsBurgers.Tables["tblBurgers"].NewRow();
> dr["burgerType"] = "cheeseBurgerffdfd";
> dr["burgerPrice"] = 1.25;
> dsBurgers.Tables["tblBurgers"].Rows.Add(dr);
>
> //create key and initialization vector
> byte[] rijnKey = {bla bla};
> byte[] rijnIV = {bla bla};
>
> dsBurgers.WriteXml("XmlDirect.txt");
>
> //encode to file
> FileStream fin = new
> FileStream("XmlDirect.txt",FileMode.Open,FileAccess.Read);
> FileStream fout = new
> FileStream("XmlEnc.txt",FileMode.OpenOrCreate,FileAccess.Write);
> fout.SetLength(0);
> TripleDESCryptoServiceProvider rijn = new
> TripleDESCryptoServiceProvider();
> CryptoStream encStream = new
>
CryptoStream(fout,rijn.CreateEncryptor(rijnKey,rijnIV),CryptoStreamMode.Writ
e);
> long fileLength = fin.Length;
> byte[] buffer = new Byte[1];
> int amountRead = 0;
> long amountDone = 0;
> while(amountDone<fileLength)
> {
> amountRead = fin.Read(buffer,0,1);
> encStream.Write(buffer,0,amountRead);
> amountDone = amountDone + amountRead;
> }
> //fin.Read(buffer,0,Convert.ToInt32(fileLength));
> //encStream.Write(buffer,0,Convert.ToInt32(fileLength));
> fout.Close();
> fin.Close();
>
>
> //decrypt the file and make sure everything is still there
> FileStream fin2 = new
> FileStream("XmlEnc.txt",FileMode.Open,FileAccess.Read);
> FileStream fout2 = new
> FileStream("XmlOutEncDec.txt",FileMode.OpenOrCreate,FileAccess.Write);
> fout2.SetLength(0);
> CryptoStream decStream = new
>
CryptoStream(fout2,rijn.CreateDecryptor(rijnKey,rijnIV),CryptoStreamMode.Wri
te);
> long fileLen = fin2.Length;
> amountRead = 0;
> amountDone = 0;
> while(amountDone<fileLen)
> {
> amountRead = fin2.Read(buffer,0,1);
> decStream.Write(buffer,0,amountRead);
> amountDone += amountRead;
> }
>
> //fin2.Read(buffer,0,Convert.ToInt32(fileLen));
> //decStream.Write(buffer,0,Convert.ToInt32(fileLen));
>
> fin2.Close();
> fout2.Close();
>
> ___________________________________
> changing encStream or decStream to fout and fout2 fixes everything,
> which makes me think it could be a problem with the cryptostreams
> themselves or there is something I don't know about their behavior
> that would cause the truncation.
>
> If anyone knows the answer please help.
> Thanks and code on!
> Matt

Bill,

If you are out there, thankyou so much for your response. I was
banging my head on the wall for 48 hours going over and over that.
That seems to have fixed the problem.

Code on,
Matt