C#

JWE using A256GCMKW

See more JSON Web Encryption (JWE) Examples

This example demonstrates creating a JCE with AES GCM key wrap. C#

bool success = false;

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

string plaintext = "My text to enrypt";

Chilkat.Jwe jwe = new Chilkat.Jwe();

//  First build the JWE Protected Header: 

//          {
//              "alg": "A256GCMKW",
//              "kid": "18ec08e1-bfa9-4d95-b205-2b4dd1d4321d",
//              "tag": "kfPduVQ3T3H6vnewt--ksw",
//              "iv": "KkYT0GX_2jHlfqN_",
//              "enc": "A128CBC-HS256"
//          }

Chilkat.JsonObject jweProtHdr = new Chilkat.JsonObject();
jweProtHdr.AppendString("alg","A256GCMKW");
//  kid is optional
jweProtHdr.AppendString("kid","18ec08e1-bfa9-4d95-b205-2b4dd1d4321d");
//  tag is optional
jweProtHdr.AppendString("tag","kfPduVQ3T3H6vnewt--ksw");
jweProtHdr.AppendString("enc","A256GCM");
//  the iv should be 16 random chars.
Chilkat.Prng prng = new Chilkat.Prng();
jweProtHdr.AppendString("iv",prng.RandomString(16,true,true,true));
jwe.SetProtectedHeader(jweProtHdr);

Debug.WriteLine("JWE Protected Header: " + jweProtHdr.Emit());
Debug.WriteLine("--");

//  Given that we have 256-bit AES, our key should be 32 bytes.
//  The ascii string here is 32 bytes, therefore the 2nd arg is "ascii" to use these
//  ascii chars directly as the key.
string aesWrappingKey = "2baf4f730f5e4542b428593ef9cceb0e";
jwe.SetWrappingKey(0,aesWrappingKey,"ascii");

//  Encrypt and return the JWE:
string strJwe = jwe.Encrypt(plaintext,"utf-8");
if (jwe.LastMethodSuccess != true) {
    Debug.WriteLine(jwe.LastErrorText);
    return;
}

//  Show the JWE we just created:
Debug.WriteLine(strJwe);

//  Decrypt the JWE that was just produced.
//  1) Load the JWE.
//  2) Set the AES wrapping key.
//  3) Decrypt.
Chilkat.Jwe jwe2 = new Chilkat.Jwe();
success = jwe2.LoadJwe(strJwe);
if (success != true) {
    Debug.WriteLine(jwe2.LastErrorText);
    return;
}

//  Set the AES wrap key.  Important to use "ascii"
jwe2.SetWrappingKey(0,aesWrappingKey,"ascii");

//  Decrypt.
string originalPlaintext = jwe2.Decrypt(0,"utf-8");
if (jwe2.LastMethodSuccess != true) {
    Debug.WriteLine(jwe2.LastErrorText);
    return;
}

Debug.WriteLine("original text: ");
Debug.WriteLine(originalPlaintext);