てすと。

<p id="moge"><input placeholder="input passphrase"><button>Decrypt</button></p><p id="plain"></p><p id="encrypted" style="word-wrap:break-word">U2FsdGVkX1/hWB0mar2Di4sPqvgRhr4rXdxbndw4iRyrWu2oUWcmI+Mj4nFB2JaR7UsFVpZL8VPKC6F3xnAYt1H/iiOIWwq3g8RKfWugtB91xkVzoqUe1n94wxPWnMklAdYdw7w9z00VCz8cEZ6B2do8OD3JB7VGNfU3Sk68I06z2OMm9lhU78cIviJm66awLxUQ3/zg3uN2Fit7UWcNZHBHpcldPIp/HSmHJckYu1uFl0TKM0V/9sFhpK11jCiRGLXj50JK7zyrIPDBj2418DgS0pIyRVKaCBhpuggEKlKNQB274ShN+FlY9AVLrN3z9zFalm8HgU6QbDwqFkUJ9+WGziJ+t6nFOzGjeVCY3H+zxsCH8uPnAbGlUnGqbEFV</p><p><script src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/3.1.2/rollups/aes.js"></script><script>document.querySelector("#moge>button").addEventListener("click",e=>$("#plain").html(CryptoJS.AES.decrypt($("#encrypted").hide().text(),$("#moge>input").val()).toString(CryptoJS.enc.Utf8)));</script></p>