Partially hide email address in PHP - php

Question

I am building a simple friend/buddy system, and when someone tries to search for new friends, I want to show partially hidden email addresses, so as to give an idea about who the user might be, without revealing the actual details.
So I want abcdlkjlkjk#hotmail.com to become abcdl******#hotmail.com.
As a test I wrote:
<?php
$email = "abcdlkjlkjk#hotmail.com";
$em = explode("#",$email);
$name = $em[0];
$len = strlen($name);
$showLen = floor($len/2);
$str_arr = str_split($name);
for($ii=$showLen;$ii<$len;$ii++){
$str_arr[$ii] = '*';
}
$em[0] = implode('',$str_arr);
$new_name = implode('#',$em);
echo $new_name;
This works, but I was wondering if there was any easier/shorter way of applying the same logic? Like a regex maybe?

Answer 1

here's something quick:
function obfuscate_email($email)
{
$em = explode("#",$email);
$name = implode('#', array_slice($em, 0, count($em)-1));
$len = floor(strlen($name)/2);
return substr($name,0, $len) . str_repeat('*', $len) . "#" . end($em);
}
// to see in action:
$emails = ['"Abc\#def"#iana.org', 'abcdlkjlkjk#hotmail.com'];
foreach ($emails as $email)
{
echo obfuscate_email($email) . "\n";
}
echoes:
"Abc\*****#iana.org
abcdl*****#hotmail.com
uses substr() and str_repeat()

Answer 2

Maybe this is not what you want, but I would go for this:
<?php
/*
Here's the logic:
We want to show X numbers.
If length of STR is less than X, hide all.
Else replace the rest with *.
*/
function mask($str, $first, $last) {
$len = strlen($str);
$toShow = $first + $last;
return substr($str, 0, $len <= $toShow ? 0 : $first).str_repeat("*", $len - ($len <= $toShow ? 0 : $toShow)).substr($str, $len - $last, $len <= $toShow ? 0 : $last);
}
function mask_email($email) {
$mail_parts = explode("#", $email);
$domain_parts = explode('.', $mail_parts[1]);
$mail_parts[0] = mask($mail_parts[0], 2, 1); // show first 2 letters and last 1 letter
$domain_parts[0] = mask($domain_parts[0], 2, 1); // same here
$mail_parts[1] = implode('.', $domain_parts);
return implode("#", $mail_parts);
}
$emails = array(
'a#a.com',
'ab#aa.com',
'abc#aaa.com',
'abcd#aaaa.com',
'abcde#aaaaa.com',
'abcdef#aaaaaa.com',
'abcdefg#aaaaaaa.com',
'abcdefgh#aaaaaaaa.com',
'abcdefghi#aaaaaaaaa.com'
);
foreach ($emails as $email){
echo '<b>'.$email.'</b><br>'.mask_email($email).'<br><hr>';
}
Result:
a#a.com
*#*.com
ab#aa.com
**#**.com
abc#aaa.com
***#***.com
abcd#aaaa.com
ab*d#aa*a.com
abcde#aaaaa.com
ab**e#aa**a.com
abcdef#aaaaaa.com
ab***f#aa***a.com
abcdefg#aaaaaaa.com
ab****g#aa****a.com
abcdefgh#aaaaaaaa.com
ab*****h#aa*****a.com
abcdefghi#aaaaaaaaa.com
ab******i#aa******a.com

Answer 3

Here's my alternate solution for this.
I wouldn't use the exact number of mask characters to match the original length of the email, but rather use a fixed length mask for privacy reasons. I would also set the maximum allowed characters to show as well as never show more than half of the email. I would also mask all emails less than a minimum length.
With those rules in mind, here's my function with optional parameters:
function maskEmail($email, $minLength = 3, $maxLength = 10, $mask = "***") {
$atPos = strrpos($email, "#");
$name = substr($email, 0, $atPos);
$len = strlen($name);
$domain = substr($email, $atPos);
if (($len / 2) < $maxLength) $maxLength = ($len / 2);
$shortenedEmail = (($len > $minLength) ? substr($name, 0, $maxLength) : "");
return "{$shortenedEmail}{$mask}{$domain}";
}
Tests:
$email = "";
$tests = [];
for ($i=0; $i < 22; $i++) {
$email .= chr(97 + $i);
$tests[] = $email . " -> " . maskEmail("{$email}#example.com");
}
print_r($tests);
Results:
Array
(
[0] => a -> ***#example.com
[1] => ab -> ***#example.com
[2] => abc -> ***#example.com
[3] => abcd -> ab***#example.com
[4] => abcde -> ab***#example.com
[5] => abcdef -> abc***#example.com
[6] => abcdefg -> abc***#example.com
[7] => abcdefgh -> abcd***#example.com
[8] => abcdefghi -> abcd***#example.com
[9] => abcdefghij -> abcde***#example.com
[10] => abcdefghijk -> abcde***#example.com
[11] => abcdefghijkl -> abcdef***#example.com
[12] => abcdefghijklm -> abcdef***#example.com
[13] => abcdefghijklmn -> abcdefg***#example.com
[14] => abcdefghijklmno -> abcdefg***#example.com
[15] => abcdefghijklmnop -> abcdefgh***#example.com
[16] => abcdefghijklmnopq -> abcdefgh***#example.com
[17] => abcdefghijklmnopqr -> abcdefghi***#example.com
[18] => abcdefghijklmnopqrs -> abcdefghi***#example.com
[19] => abcdefghijklmnopqrst -> abcdefghij***#example.com
[20] => abcdefghijklmnopqrstu -> abcdefghij***#example.com
[21] => abcdefghijklmnopqrstuv -> abcdefghij***#example.com
)

Answer 4

For instance :
substr($email, 0, 3).'****'.substr($email, strpos($email, "#"));
Which will give you something like:
abc****#hotmail.com

Answer 5

I'm using this:
function secret_mail($email)
{
$prop=2;
$domain = substr(strrchr($email, "#"), 1);
$mailname=str_replace($domain,'',$email);
$name_l=strlen($mailname);
$domain_l=strlen($domain);
for($i=0;$i<=$name_l/$prop-1;$i++)
{
$start.='x';
}
for($i=0;$i<=$domain_l/$prop-1;$i++)
{
$end.='x';
}
return substr_replace($mailname, $start, 2, $name_l/$prop).substr_replace($domain, $end, 2, $domain_l/$prop);
}
Will output something like:
cyxxxxxone#gmxxxxcom

Answer 6

I created a function can help someone
function hideEmail($email)
{
$mail_parts = explode("#", $email);
$length = strlen($mail_parts[0]);
$show = floor($length/2);
$hide = $length - $show;
$replace = str_repeat("*", $hide);
return substr_replace ( $mail_parts[0] , $replace , $show, $hide ) . "#" . substr_replace($mail_parts[1], "**", 0, 2);
}
hideEmail("name#example.com"); // output: na**#**ample.com
hideEmail("something#example.com"); // output: some*****#**ample.com
You can customize as you want .. something like this (if length is 4 or less display only the first)
function hideEmail($email) {
$mail_parts = explode("#", $email);
$length = strlen($mail_parts[0]);
if($length <= 4 & $length > 1)
{
$show = 1;
}else{
$show = floor($length/2);
}
$hide = $length - $show;
$replace = str_repeat("*", $hide);
return substr_replace ( $mail_parts[0] , $replace , $show, $hide ) . "#" . substr_replace($mail_parts[1], "**", 0, 2);
}
hideEmail("name#example.com"); // output: n***#**ample.com
hideEmail("something#example.com"); // output: some*****#**ample.com

Answer 7

Very simple RegExp way:
$email = preg_replace('/\B[^#.]/', '*', $email)
Results:
john#smith.com: j***#s*****.c**
abcdef#example.org: a*****#e******.o**
abcdef: a*****

Answer 8

Sometimes its good to show the last character too.
ABCDEFZ#gmail.com becomes
A*****Z#gmail.com
I will suggest you keep things simple.
Maybe something like this is simple enough
https://github.com/fedmich/PHP_Codes/blob/master/mask_email.php
Masks an email to show first 3 characters and then the last character before the # sign
function mask_email( $email ) {
/*
Author: Fed
Simple way of masking emails
*/
$char_shown = 3;
$mail_parts = explode("#", $email);
$username = $mail_parts[0];
$len = strlen( $username );
if( $len <= $char_shown ){
return implode("#", $mail_parts );
}
//Logic: show asterisk in middle, but also show the last character before #
$mail_parts[0] = substr( $username, 0 , $char_shown )
. str_repeat("*", $len - $char_shown - 1 )
. substr( $username, $len - $char_shown + 2 , 1 )
;
return implode("#", $mail_parts );
}

Answer 9

I m using femich answer above and tweak it a bit for my
function mask_email($email, $char_shown_front = 1, $char_shown_back = 1)
{
$mail_parts = explode('#', $email);
$username = $mail_parts[0];
$len = strlen($username);
if ($len < $char_shown_front or $len < $char_shown_back) {
return implode('#', $mail_parts);
}
//Logic: show asterisk in middle, but also show the last character before #
$mail_parts[0] = substr($username, 0, $char_shown_front)
. str_repeat('*', $len - $char_shown_front - $char_shown_back)
. substr($username, $len - $char_shown_back, $char_shown_back);
return implode('#', $mail_parts);
}
test123#gmail.com -> t*****3#gmail.com
you can pass in the number of character to show in the front and in the back

Answer 10

You can also try this....
<?php
$email = "abcdlkjlkjk#hotmail.com";
$resultmob = substr($email,0,5);
$resultmob .= "**********";
$resultmob .= substr($email,strpos($email, "#"));
echo $resultmob;
?>
Answer:-
abcdl******#hotmail.com

Answer 11

Another variant that was heavily influenced by the answers already shared.
This has two key extra benefits:
It keeps the first characters after a defined set of delimiters, making it more readable while still preserving privacy.
It works with longer domain endings such as .org.uk and .com.au
Example: firstname.lastname#example.co.uk becomes f********.l*******#e*****.c*.u*
function mask_email( $email ) {
$masked = '';
$show_next = true;
foreach ( str_split( $email ) as $chr ) {
if ( $show_next ) {
$masked .= $chr;
$show_next = false;
}
else if ( in_array( $chr, array('.', '#', '+') ) ) {
$masked .= $chr;
$show_next = true;
}
else {
$masked .= '*';
$show_next = false;
}
}
return $masked;
}

Answer 12

Try this function. This will work with valid emails, such as "Abc\#def"#iana.org.
function hideEmail($email){
$prefix = substr($email, 0, strrpos($email, '#'));
$suffix = substr($email, strripos($email, '#'));
$len = floor(strlen($prefix)/2);
return substr($prefix, 0, $len) . str_repeat('*', $len) . $suffix;
}
echo hideEmail('abcdljtrsjtrsjlkjk#hotmail.com');
echo hideEmail('"abc\#def"#iana.org');
Returns
abcdljtrs*********#hotmail.com
"abc\*****#iana.org

Answer 13

I have a function
function hide_email($email){
$final_str = '';
$string = explode('#', $email);
$leftlength = strlen($string[0]);
$string2 = explode('.', $string[1]);
$string2len = strlen($string2[0]);
$leftlength_new = $leftlength-1;
$first_letter = substr($string[0], 0,1);
$stars = '';
$stars2 = '';
for ($i=0; $i < $leftlength_new; $i++) {
$stars .= '*';
}
for ($i=0; $i < $string2len; $i++) {
$stars2 .= '*';
}
$stars;
return $final_str .= $first_letter.$stars.'#'.$stars2.'.'.$string2[1];
}
echo hide_email('Hello#PHP.com');

Answer 14

There was an issue in case if there would be 1 character before #. I have fixed in below function.
function obfuscate_email($email)
{
$em = explode("#",$email);
if(strlen($em[0])==1){
return '*'.'#'.$em[1];
}
$name = implode(array_slice($em, 0, count($em)-1), '#');
$len = floor(strlen($name)/2);
return substr($name,0, $len) . str_repeat('*', $len) . "#" . end($em);
}

Answer 15

Here is version with only 2 lines (if you remove function stuff).
<?php
function censor_email($str,$amount=2, $char='*') {
list($local, $domain)=explode("#",$str);
return substr($local,0,$amount).str_repeat($char,strlen($local)-$amount)."#".$domain;
}
?>

Answer 16

function maskEmail($email) {
preg_match('/^.?(.*)?.#.+$/', $email, $matches);
return str_replace($matches[1], str_repeat('*', strlen($matches[1])), $email);
}
echo maskEmail('abcdefgh#example.com')
echo maskEmail('abh#example.com')
echo maskEmail('ah#example.com')
echo maskEmail('a#example.com')
returns
a******h#example.com
a*h#example.com
ah#example.com
a#example.com

Answer 17

This is what I did, as I required exact number of string count same as plain email.
This function only shows first & last two characters before "#"
function mask_email($email)
{
$em = explode("#",$email);
$len = strlen($em[0]);
$substr_count = 1;
if($len > 6)
$substr_count = 2;
$first = substr($em[0], 0,$substr_count);
$last = substr($em[0], -$substr_count);
$no_of_star = $len - ($substr_count * 2);
return $first.str_repeat('*', $no_of_star).$last."#".end($em);
}

Answer 18

Though this is an old thread & has many answers already. I want to share my own snippet too.
Which checks if it's a valid email or not.
How much characters to censor & to show.
What character should be used to censor.
function get_censored_email($email, $show_chars = 3, $censor_char = '*'){
if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
$char_length = strlen($email);
$censor_count = $char_length - $show_chars;
$return_email = substr($email, 0, $show_chars);
$return_email .= str_repeat("*", $censor_count);
return $return_email;
}
}
$email = 'noman.ibrahim115#gmail.com';
echo get_censored_email($email, 3, '*'); // returns nom***********************

Answer 19

Method 1:
<?php
function hideEmailAddress($email) {
if(filter_var($email, FILTER_VALIDATE_EMAIL)) {
list($first, $last) = explode('#', $email);
$first = str_replace(substr($first, '3'), str_repeat('*', strlen($first)-3), $first);
$last = explode('.', $last);
$last_domain = str_replace(substr($last['0'], '1'), str_repeat('*', strlen($last['0'])-1), $last['0']);
$hideEmailAddress = $first.'#'.$last_domain.'.'.$last['1'];
return $hideEmailAddress;
}
}
$email = "test#example.com";
echo hideEmailAddress($email);
?>
Method 2:
<?php
function hideEmailAddress($email) {
$em = explode("#",$email);
$name = implode(array_slice($em, 0, count($em)-1), '#');
$len = floor(strlen($name)/2);
return substr($name,0, $len) . str_repeat('*', $len) . "#" . end($em);
}
$email = 'test#example.com';
echo hideEmailAddress($email);
?>