Bug #80870 [Com]: base64_decode: Concatenated base64 blocks are corrupted

Edit report at https://bugs.php.net/bug.php?id=80870&edit=1 ID: 80870 Comment by: bugs at jth dot net Reported by: bugs at jth dot net Summary: base64_decode: Concatenated base64 blocks are corrupted Status: Open Type: Bug Package: Strings related Operating System: Linux PHP Version: 7.4.16 Block user comment: N Private report: N New Comment: > Please, understand, that we are handling emails > sent to a server from the outside world composed > by a variety of email clients out of our control please understand that everybody dealing with email has that issue and solving that properly is far outside of a naive usage of base64 / string functions it's far outside of the scope of a programming language you are wrong here - look how mail-clients linke rouncube written in php deal with emails! again: you are wrong here, base64_decode alone can't handle emails, period Previous Comments: ------------------------------------------------------------------------ [2021-03-16 18:59:40] bugs at jth dot net Please, understand, that we are handling emails sent to a server from the outside world composed by a variety of email clients out of our control. The emails are handled by a PHP program handling incoming emails as input to a special service. Please, relate to the fact that the linux base64 program is handling this case correctly, whereas base64_decode is corrupting data. There is absolutely no reason for this difference. Correcting it does not cause any backwards compatibility problems, as I assume nobody is using base64_decode for generating partly corrupt data. ------------------------------------------------------------------------ [2021-03-16 17:32:18] dgdgeg dot evrgrh at ggg dot ag your mail client properly deals with mime-mail which is *highly* complex especially when it comes to nesting ------------------------------------------------------------------------ [2021-03-16 16:48:06] bugs at jth dot net The case is: The email program will produce the email body as a valid base64 block and concatenate the selected signature as a separate valid base64 block. Thus the email body will consist of two valid base64 blocks. Using the linux base64 program this body is decoded correctly. As we are using a PHP script to interpret emails from different sources, this base64_decode behaviour is highly inconvenient and I don't see, why it cannot decode consequtive base64 blocks correctly instead of the current partly corrupted way. ------------------------------------------------------------------------ [2021-03-15 22:20:23] requinix@php.net = is not valid for Base64 when located in the middle of an input string. As such it will be ignored (since $strict is not being used) and PHP will attempt to decode "TGluZSBuciAxIGJjZGVmZwoTGluZSBuciAyIAo=". The line feed is irrelevant. What is this "may occur as input from an email"? ------------------------------------------------------------------------ [2021-03-15 20:28:36] bugs at jth dot net Description: ------------ When decoding a string containing two or more base64 blocks with line feeds in the base64 text the latter blocks are corrupted. This may occur as input from an email generated by some mail programs. Test script: --------------- $s1 = base64_encode("Line nr 1 bcdefg\n"); $s2 = base64_encode("Line nr 2 \n"); $str = $s1."\n".$s2; echo $str echo base64_decode($str); Expected result: ---------------- TGluZSBuciAxIGJjZGVmZwo= TGluZSBuciAyIAo= Line nr 1 bcdefg Line nr 2 Actual result: -------------- Result: TGluZSBuciAxIGJjZGVmZwo= TGluZSBuciAyIAo= Line nr 1 bcdefg (corrupted text) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=80870&edit=1