File Encryption / Decryption

Download: Chilkat .NET Assemblies

File-to-file encryption in C# using AES, Blowfish, RC2, ARC4, or 3DES.

Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

bool success;
success = crypt.UnlockComponent("Anything for 30-day trial");
if (success != true) {
    MessageBox.Show("Crypt component unlock failed");
    return;
}

crypt.CryptAlgorithm = "aes";
crypt.CipherMode = "cbc";
crypt.KeyLength = 128;

string key;
//  16 bytes of key for 128-bit encryption.
key = "1234567890123456";

//  The IV is equal to the block size of the encryption algorithm.
string iv;
iv = "1234567890123456";

//  Set the key.
crypt.SetEncodedKey(key,"ascii");

//  Set the IV
crypt.SetEncodedIV(iv,"ascii");

//  AES Encrypt the file (the file may be any size because it will
//  stream the file in/out.
success = crypt.CkEncryptFile("hamlet.xml","aesEncrypted.dat");
if (success != true) {
    MessageBox.Show(crypt.LastErrorText);
    return;
}

//  AES Decrypt the file (the file may be any size because it will
//  stream the file in/out.
success = crypt.CkDecryptFile("aesEncrypted.dat","hamlet_aes.xml");
if (success != true) {
    MessageBox.Show(crypt.LastErrorText);
    return;
}

MessageBox.Show("AES File Encryption Success.");

//  Now do 3DES file encryption:

//  To use Triple-DES, set the algorithm = "des",
//  and the key length = 168.
//  To use DES, set the key length = 56 bits.
crypt.CryptAlgorithm = "des";
crypt.CipherMode = "cbc";
crypt.KeyLength = 168;

//  3DES Encrypt the file
success = crypt.CkEncryptFile("hamlet.xml","tripleDesEncrypted.dat");
if (success != true) {
    MessageBox.Show(crypt.LastErrorText);
    return;
}

//  3DES Decrypt the file
success = crypt.CkDecryptFile("tripleDesEncrypted.dat","hamlet_3des.xml");
if (success != true) {
    MessageBox.Show(crypt.LastErrorText);
    return;
}

MessageBox.Show("3DES File Encryption Success.");

//  Do Blowfish file encryption:

//  To use Blowfish, set the algorithm = "blowfish2".
//  The original Chilkat "blowfish" implementation outputs
//  4321 swapped bytes.  "blowfish2" output is in the correct
//  byte order.
crypt.CryptAlgorithm = "blowfish2";
crypt.CipherMode = "cbc";
crypt.KeyLength = 128;

//  Blowfish Encrypt the file
success = crypt.CkEncryptFile("hamlet.xml","blowfishEncrypted.dat");
if (success != true) {
    MessageBox.Show(crypt.LastErrorText);
    return;
}

//  Blowfish Decrypt the file
success = crypt.CkDecryptFile("blowfishEncrypted.dat","hamlet_blowfish.xml");
if (success != true) {
    MessageBox.Show(crypt.LastErrorText);
    return;
}

MessageBox.Show("Blowfish File Encryption Success.");

//  Do RC2 file encryption:

//  To use RC2, set the algorithm = "rc2".
//  Also, set the Rc2EffectiveKeyLength property.
crypt.CryptAlgorithm = "rc2";
crypt.CipherMode = "cbc";
//  Key length and effective key length should range
//  from 8 to 1024 bits.
crypt.KeyLength = 128;
crypt.Rc2EffectiveKeyLength = 128;

//  RC2 Encrypt the file
success = crypt.CkEncryptFile("hamlet.xml","rc2Encrypted.dat");
if (success != true) {
    MessageBox.Show(crypt.LastErrorText);
    return;
}

//  RC2 Decrypt the file
success = crypt.CkDecryptFile("rc2Encrypted.dat","hamlet_rc2.xml");
if (success != true) {
    MessageBox.Show(crypt.LastErrorText);
    return;
}

MessageBox.Show("RC2 File Encryption Success.");

//  Do ARC4 file encryption:

//  To use ARC4, set the algorithm = "arc4".
crypt.CryptAlgorithm = "arc4";
crypt.KeyLength = 128;

//  ARC4 Encrypt the file
success = crypt.CkEncryptFile("hamlet.xml","arc4Encrypted.dat");
if (success != true) {
    MessageBox.Show(crypt.LastErrorText);
    return;
}

//  ARC4 Decrypt the file
success = crypt.CkDecryptFile("arc4Encrypted.dat","hamlet_arc4.xml");
if (success != true) {
    MessageBox.Show(crypt.LastErrorText);
    return;
}

MessageBox.Show("ARC4 File Encryption Success.");