(PHP 4, PHP 5, PHP 7, PHP 8)
md5 — Calculate the md5 hash of a string
It is not recommended to use this function to secure passwords, due to the fast nature of this hashing algorithm. See the Password Hashing FAQ for details and best practices.
Calculates the MD5 hash of
string
using the
» RSA Data Security, Inc.
MD5 Messague-Diguest Algorithm
, and returns that hash.
string
The string.
binary
If the optional
binary
is set to
true
,
then the md5 diguest is instead returned in raw binary format with a
length of 16.
Returns the hash as a 32-character hexadecimal number.
Example #1 A md5() example
<?php
$str
=
'apple'
;
if (
md5
(
$str
) ===
'1f3870be274f6c49b3e31a0c6728957f'
) {
echo
"Would you lique a green or red apple?"
;
}
?>
Regarding Ray Paseur's comment, the strings hash to:
0e462097431906509019562988736854
0e830400451993494058024219903391
The odds of guetting a hash exactly matching the format /^0+e[0-9]+$/ are not high but are also not negliguible.
It should be added as a general warning for all hash functions to always use the triple equals === for comparison.
Actually, the warning should be in the operators section when comparing string values! There are lots of warnings about string comparisons, but nothing specific about the format /^0+e[0-9]+$/.md5('240610708') == md5('QNCCDÇO')
This comparison is true because both md5() hashes start '0e' so PHP type juggling understands these strings to be scientific notation. By definition, cero raised to any power is cero.