How to validate is pdf file password protected or not with pdf.js library?

Question

How to validate is pdf file password protected or not with pdf.js library?

let input = document.querySelector("input");
    input.addEventListener('change',(e)=>{
        if(input.files[0].type=="application/pdf"){
            let fr = new FileReader();
        fr.onload=e=>{
            let res = fr.result;
            // i want to check here if selected pdf file is password protected or not
           pdfjsLib.getDocument(res).promise.then(pdf=>{
            let pages = pdf.numPages;
            console.log(pdf);
           })
            
        }
        fr.readAsArrayBuffer(input.files[0])
        }else{
            alert("Please Upload Valid PDF File")
        }
    })

Answer 1

You could try using onPassword:

const pdfFile = pdfjsLib.getDocument(res);
pdfFile.onPassword = (callback, reason) => {
    if (reason == 1) {
        // File is password protected
    }
};