decryption.js

var graphene = require("graphene-pk11");
var Module = graphene.Module;

var lib = "/opt/local/lib/softhsm/libsofthsm2.so";

var mod = Module.load(lib, "SoftHSM");
var SessionFlag = graphene.SessionFlag;
var UserType = graphene.UserType;

mod.initialize();

var slot = mod.getSlots(2);
if (slot.flags & graphene.SlotFlag.TOKEN_PRESENT) {
    var session = slot.open(SessionFlag.SERIAL_SESSION | SessionFlag.RW_SESSION);
    session.login("8888",UserType.USER);

    // enc algorithm
    var alg = {
        name: "AES_CBC_PAD",
        params: new Buffer([1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6]) // IV
    };

    // generate AES key
    var key = session.generateKey(graphene.KeyGenMechanism.AES, {
        "class": graphene.ObjectClass.SECRET_KEY,
        "token": false,
        "valueLen": 256 / 8,
        "keyType": graphene.KeyType.AES,
        "label": "My AES secret key",
        "encrypt": true,
        "decrypt": true
    });

    // decrypting
    var enc = new Buffer("196edd82ecca5e7df08090edf2cb3322", "hex");
    console.log("Enc:", enc);            // Message: Encrypted message
    
    var dec = session.createDecipher(alg, key).once(enc, new Buffer(enc.byteLength));
    console.log("Message:", dec.toString());            // Message: decrypted message

    session.logout();
    session.close();
}
else {
    console.error("Slot is not initialized");
}

mod.finalize();

You are generating new key. You cannot use such key for decryption. You need the same key which you used for encryption. You can use C_CreateObject or C_FindObject to get the same key

I don't have any idea how to do the finding object of encrypted. Can you give us help for that. Thanks in advance.

Do you have sample on how to get the session generated key and match it for decryption.

I found this physical object created on my machine when I set to token to true.