System.Security.Cryptography for encrypting binary files (not plain text)
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Is there a way to use the .NET cryptography library to encrypt binary files as opposed to plain text files? I've been having a few issues with the way that encrypted bytes are decrypted back to their original state. What I do to initialize my algorithm for decryption is approximately the following:
UnicodeEncoding byteConverter = new UnicodeEncoding();
RijndaelManaged algorithm = new RijndaelManaged();
algorithm.IV = byteConverter->GetBytes(/*a unicode string converted to bytes for init vector*/);
algorithm.Key = byteConverter->GetBytes(/*a unicode string converted to bytes for password*/);
return alg; //returned as base class "SymmetricAlgorithm"In order to encrypt, first, I call that stub of algorithm initialization code. Then I do approximately the following with a
Byte[] datathat I want to encrypt:MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, algorithm.CreateEncryptor(), CryptoStreamMode.Write);
for (int i = 0; i < numBytes; i++)
{
cs.WriteByte(data[i]);
}
cs.FlushFinalBlock();
byte encoded[] = ms.ToArray();
cs.Close();
ms.Close();
string output = Convert.ToBase64String(encoded);In order to decrypt, first, I call that stub of algorithm initialization code. Then I do approximately the following with a
string inputthat I want to decrypt:byte[] encoded = Convert.FromBase64String(input);
MemoryStream ms = new MemoryStream(encoded);
CryptoStream cs = new CryptoStream(ms, algorithm.CreateDecryptor(), CryptoStreamMode.Read);
byte decoded[] = new byte[encoded.Length];
for (int i = 0; i < decoded.Length; i++)
{
int readByte = cs.ReadByte();
if (readByte != -1)
{
decoded[i] = (byte)readByte;
}
}
cs.Close();
ms.Close();The problem is that if I call
Encrypt, thenDecrypt, encryption leaves me with a nice base64 string, which decrypt easily converts back to a byte array. But when I read the CryptoStream and get check all the values ofint readByteeverytime I read a byte, as soon as I come to the null-terminated character (0 ''), everything else that I read after that is the same garbage symbol (-51 'Í'). More precisely, the code that I'm writing here is the C# equivalent of my Managed C++ code (however, the problem does not lie in the unmanaged part or the unmanaged/managed conversion). So, to rephrase what I mean, say that I'm checking all the values of readByte for i = 0 to the length of the decoded b -
Is there a way to use the .NET cryptography library to encrypt binary files as opposed to plain text files? I've been having a few issues with the way that encrypted bytes are decrypted back to their original state. What I do to initialize my algorithm for decryption is approximately the following:
UnicodeEncoding byteConverter = new UnicodeEncoding();
RijndaelManaged algorithm = new RijndaelManaged();
algorithm.IV = byteConverter->GetBytes(/*a unicode string converted to bytes for init vector*/);
algorithm.Key = byteConverter->GetBytes(/*a unicode string converted to bytes for password*/);
return alg; //returned as base class "SymmetricAlgorithm"In order to encrypt, first, I call that stub of algorithm initialization code. Then I do approximately the following with a
Byte[] datathat I want to encrypt:MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, algorithm.CreateEncryptor(), CryptoStreamMode.Write);
for (int i = 0; i < numBytes; i++)
{
cs.WriteByte(data[i]);
}
cs.FlushFinalBlock();
byte encoded[] = ms.ToArray();
cs.Close();
ms.Close();
string output = Convert.ToBase64String(encoded);In order to decrypt, first, I call that stub of algorithm initialization code. Then I do approximately the following with a
string inputthat I want to decrypt:byte[] encoded = Convert.FromBase64String(input);
MemoryStream ms = new MemoryStream(encoded);
CryptoStream cs = new CryptoStream(ms, algorithm.CreateDecryptor(), CryptoStreamMode.Read);
byte decoded[] = new byte[encoded.Length];
for (int i = 0; i < decoded.Length; i++)
{
int readByte = cs.ReadByte();
if (readByte != -1)
{
decoded[i] = (byte)readByte;
}
}
cs.Close();
ms.Close();The problem is that if I call
Encrypt, thenDecrypt, encryption leaves me with a nice base64 string, which decrypt easily converts back to a byte array. But when I read the CryptoStream and get check all the values ofint readByteeverytime I read a byte, as soon as I come to the null-terminated character (0 ''), everything else that I read after that is the same garbage symbol (-51 'Í'). More precisely, the code that I'm writing here is the C# equivalent of my Managed C++ code (however, the problem does not lie in the unmanaged part or the unmanaged/managed conversion). So, to rephrase what I mean, say that I'm checking all the values of readByte for i = 0 to the length of the decoded bSkip the base 64 string part. Since you are using a binary file you should be using a FileStream or some other stream. I have never had any trouble encrypting streams.
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Happiness in intelligent people is the rarest thing I know. -- Ernest Hemingway
Most of this sig is for Google, not ego. -
Skip the base 64 string part. Since you are using a binary file you should be using a FileStream or some other stream. I have never had any trouble encrypting streams.
Need software developed? Offering C# development all over the United States, ERL GLOBAL, Inc is the only call you will have to make.
Happiness in intelligent people is the rarest thing I know. -- Ernest Hemingway
Most of this sig is for Google, not ego.Well, base64 is easily encoded in a string, or a MemoryStream (which is what I'm using). What I'm essentially doing afterwards when I write to a file is actually saving the base64 encoded string directly to the file like I save text. Thanks for the FileStream suggestion... maybe that's also a plausible implementation. Also, I've toyed around with the idea of doing multiple base64 conversions, so converting a binary file to base64 first, then encrypting, then encoding to base64 again. After every base64 transform step, I'm able to again fit the entire "data" of the file into an ANSI string.
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Well, base64 is easily encoded in a string, or a MemoryStream (which is what I'm using). What I'm essentially doing afterwards when I write to a file is actually saving the base64 encoded string directly to the file like I save text. Thanks for the FileStream suggestion... maybe that's also a plausible implementation. Also, I've toyed around with the idea of doing multiple base64 conversions, so converting a binary file to base64 first, then encrypting, then encoding to base64 again. After every base64 transform step, I'm able to again fit the entire "data" of the file into an ANSI string.
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I just figured out the issue, and it had nothing to do with the CryptoStream. I was simply deceived and made the wrong assumptions. In the end, it was because I never opened the file in binary mode, so it was being parsed as a string.
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I just figured out the issue, and it had nothing to do with the CryptoStream. I was simply deceived and made the wrong assumptions. In the end, it was because I never opened the file in binary mode, so it was being parsed as a string.
This is a little library I use. I pulled it together from various sources and stake no claim to it. It will encrypt binary and strings using public/private key encryption and standard passphrase encryption. Hope it's of some help. Crptography.zip[^]