Encrypt and decrypt text

gistfile1.txt

async function deriveKey(plaintextKey) {
    const baseKey = await window.crypto.subtle.importKey("raw", new TextEncoder().encode(plaintextKey), "PBKDF2", false, ["deriveKey"]);
    return window.crypto.subtle.deriveKey(
        {
            name: "PBKDF2",
            salt: new TextEncoder().encode("some-salt"),
            iterations: 10000,
            hash: "SHA-256"
        },
        baseKey,
        {
            name: "AES-GCM",
            length: 256
        },
        true,
        ["encrypt", "decrypt"]
    );
}
async function encryptWithKey(text, key) {
    const secretKey = await deriveKey(key);
    const iv = window.crypto.getRandomValues(new Uint8Array(12));
    const cipherText = await window.crypto.subtle.encrypt(
        {
            name: "AES-GCM",
            iv: iv
        },
        secretKey,
        new TextEncoder().encode(text)
    );
    return {
        cipherText: btoa(String.fromCharCode(...new Uint8Array(cipherText))),
        iv: btoa(String.fromCharCode(...new Uint8Array(iv)))
    };
}
async function decryptWithKey(cipherTextBase64, ivBase64, key) {
    const secretKey = await deriveKey(key);
    const cipherText = Uint8Array.from(atob(cipherTextBase64), c => c.charCodeAt(0));
    const iv = Uint8Array.from(atob(ivBase64), c => c.charCodeAt(0));
    const decrypted = await window.crypto.subtle.decrypt(
        {
            name: "AES-GCM",
            iv: iv
        },
        secretKey,
        cipherText
    );
    return new TextDecoder().decode(new Uint8Array(decrypted));
}


const psk = "my password";

(async () => {
   const result = await encryptWithKey("my secret text", psk);
   console.log("Encrypted Ciphertext:", result.cipherText);
   console.log("Encrypted IV:", result.iv);

   const decryptedText = await decryptWithKey(result.cipherText, result.iv, psk);
   console.log("Decrypted:", decryptedText);
})();