php base64_decode equivalent in javascript

Question

I need the exact base64_decode() equivalent in javascript. I did a lot of research but have encountered some problems.

I can not use javascripts atob(), as for some reason, it just returns a complete different result as phps base64_decode().

Then I found a special decode function on this page: https://developer.mozilla.org/en-US/docs/Web/API/WindowBase64/Base64_encoding_and_decoding

function Base64Decode(str, encoding = 'utf-8') {
        var bytes = base64js.toByteArray(str);
        return new (TextDecoder || TextDecoderLite)(encoding).decode(bytes);
}

function Base64Encode(str, encoding = 'utf-8') {
    var bytes = new (TextEncoder || TextEncoderLite)(encoding).encode(str);        
    return base64js.fromByteArray(bytes);
}

Which indeed gives the same result, as the php function base64_decode(), but unfortunately, you can not reverse it.

So in php you can do base64_encode(base64_decode( 'BASE_64_ENCODED_STRING' )) and you will get back your original BASE_64_ENCODED_STRING

but in Javascript

Base64Encode(Base64Decode( 'BASE_64_ENCODED_STRING' ))

won't give you back your original BASE_64_ENCODED_STRING, but I need to be able to do that. I found out, that it might be due to some UTF-8 encoding issue.

Interestingly btoa(atob( 'BASE_64_ENCODED_STRING' )) will get me back the original BASE_64_ENCODED_STRING, but as I mentioned above, it won't decode the same as phps base64_decode() anyway...

Did you try [base64.js](https://github.com/dankogai/js-base64)? — Alexander, Mar 24 '18 at 11:51
Just tried using base64.js. The result is different from the phps function. Also I can not reverse it with Base64.encode(Base64.decode('BASE_64_ENCODED_STRING')) but php can do this. — Scdev, Mar 24 '18 at 12:04

php base64_decode equivalent in javascript

0 Answers0