I am finding a length restriction with base64_encode (or possibly with echo) in PHP 4.3.9.
This works ok for me:
<?php
echo strlen(str_repeat('-', 3273)); echo strlen(base64_encode(str_repeat('-', 3273))); echo base64_encode(str_repeat('-', 3273)); ?>
But change the length to 3274 and the third echo prints nothing.
<?php
echo strlen(str_repeat('-', 3274)); echo strlen(base64_encode(str_repeat('-', 3274))); echo base64_encode(str_repeat('-', 3274)); ?>
This has obvious implications if you're wanting to encode a fairly large serialized array and echo it to a form field.