(C# UWP/WinRT) AES Encrypt String (utf-8 byte representation) and return Base64

Demonstrates how to AES encrypt the utf-8 byte representation of a string and return in base64 format.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

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

crypt.CryptAlgorithm = "aes";
crypt.CipherMode = "cbc";
crypt.KeyLength = 256;
crypt.Charset = "utf-8";
crypt.EncodingMode = "base64";

string ivHex = "000102030405060708090A0B0C0D0E0F";
crypt.SetEncodedIV(ivHex,"hex");
string keyHex = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F";
crypt.SetEncodedKey(keyHex,"hex");

string encryptedStr = crypt.EncryptStringENC("This is the original string");
Debug.WriteLine(encryptedStr);

// Let's say we want to URL encode the base64 string..
crypt.CryptAlgorithm = "none";
crypt.EncodingMode = "url";
string urlEncoded = crypt.EncryptStringENC(encryptedStr);
Debug.WriteLine(urlEncoded);

// Sample output:

//  q3fmgEqjqa9o//ZS6aPuh4Wtbrrxx/WOIQSKeVnesZg=
//  q3fmgEqjqa9o%2F%2FZS6aPuh4Wtbrrxx%2FWOIQSKeVnesZg%3D

// -------------------------------------------------------------------
// Now let's do the reverse...
// 

// We start with a string that is the binary encrypted data, base64 encoded, and then URL encoded.
string encBase64Url = "q3fmgEqjqa9o%2F%2FZS6aPuh4Wtbrrxx%2FWOIQSKeVnesZg%3D";

// We'll use the same crypt object.  If using a new instance of the crypt object,
// make sure *all* settings are identical:  the algorithm, cipher mode, key length, charset, encoding mode, IV, and secret key.

// Decode from URL...
crypt.CryptAlgorithm = "none";
crypt.EncodingMode = "url";
string encBase64 = crypt.DecryptStringENC(urlEncoded);
Debug.WriteLine(encBase64);

// Now decrypt...
crypt.CryptAlgorithm = "aes";
crypt.EncodingMode = "base64";
string originalStr = crypt.DecryptStringENC(encBase64);
Debug.WriteLine(originalStr);