Encoding a email address that can be used as part of a URL in codeigniter - email

Question

Is there a way to encode a email address that can be used as a part of a url in codeigniter?. I need to decode back the email address from the url.
What I am trying to do is just a -forgotten password recovery- thing. I send a confirmation link to the user's email address, the link needs to be like ../encodedEmail/forgottenPasswordCode (with the forgottenPasswordCode updated in the db for the user with the submitted email).
When the user visits that link, I decode the email(if the email - forgottenPasswordCode pair is in the table), i allow them to reset their password (and i reset forgottenPasswordCode back to null).
I could just do a loop -checking the table with a select query- (or) -set that forgottenPasswordCode column unique, so i keep generating on a insert failure(would that be a lot faster ?)- until I generate a forgottenPasswordCode that doesn't already exist in the table.
But the guy I do this for would not accept it this way:). He wants the checking be done with the user's email, he thinks its much faster.
I am working with codeigniter, I used its encode() function, it seems to produce characters like '-slashes-' at times that breaks the encoded-email-string.
Any other ideas?

Answer 1

try using bin2hex() and hex2bin() function,
<?php
function hex2bin($str)
{
$bin = "";
$i = 0;
do
{
$bin .= chr(hexdec($str{$i}.$str{($i + 1)}));
$i += 2;
} while ($i < strlen($str));
return $bin;
}
$str = 'email#website.com';
$output = bin2hex($str);
echo $output . '<br/>';
echo hex2bin($output);
?>

Answer 2

Don't put data in the URL that doesn't have some sort of meaning. This leaves two choices:
Send the address as part of a POST. If it's coming from a web form this is the way to go.
Refer to the address in the database using an ID or hashed value. If you need the user to click a link referring to their account, use something that clearly refers to their account. If you need to refer to an instance of a password reset (many systems do this), add a table containing hashes, using that hash in the URL.
Why not just encode it in the URL?
You can see URLs (it's part of the UI), encoded things look weird
URLs represent resources, things in your app (users probably already have IDs)
Encoded email addresses are long (making these URLs harder to work with in things like emails)
Try to keep parameters in URLs to clear references to concepts in your web app (point at one user by ID or plaintext name, for example). Parameters that don't fit in URLs go in POST parameters. If you must use something encoded in a URL, prefer one-way-encoding and database lookups.

Answer 3

Although it may be not optimal design solution to use email as a part URL,
use email as base64 encoded string to avoid any issues with special chars
E.g. Base64 encoded string 'abc-def#example.com' is
YWJjLWRlZkBleGFtcGxlLmNvbQ==
In your case the URL is
../YWJjLWRlZkBleGFtcGxlLmNvbQ==/forgottenPasswordCode
All you need is to decode that string back before usage