md5

(PHP 4, PHP 5)

md5Calcula el hash md5 de un string

Descripción

string md5 ( string $str [, bool $raw_output = false ] )

Calcula el hash MD5 de str utilizando el » Algoritmo MD5 Message-Digest de RSA Data Security, Inc. y devuelve ese hash.

Parámetros

str

El string.

raw_output

Si se establece el raw_output opcional en TRUE, el resumen md5 será devuelto en formato binario sin tratar con una longitud de 16.

Valores devueltos

Devuelve el hash como un número hexadecimal de 32 caracteres.

Ejemplos

Ejemplo #1 Ejemplo de md5()

<?php
$str 
'apple';

if (
md5($str) === '1f3870be274f6c49b3e31a0c6728957f') {
    echo 
"Would you like a green or red apple?";
}
?>

Notas

Nota: Hash seguro de contraseñas

Dada la velocidad de este algoritmo de hash, se recomienda no utilizar esta función para proteger las contraeñas. Para más información, revise aquí.

Ver también

  • md5_file() - Calcula el resumen criptográfico md5 de un archivo dado
  • sha1_file() - Calcula el hash sha1 de un archivo
  • crc32() - Calcula el polinomio crc32 de una cadena
  • sha1() - Calcula el hash sha1 de un string
  • hash() - Genera un valor cifrado con base a un string
  • crypt() - Hashing de una sola vía de un string
  • password_hash() - Crea un nuevo hash de contraseña

add a note add a note

User Contributed Notes 13 notes

up
8
dionyziz at deviantart dot com
7 years ago
Sometimes it's useful to get the actual, binary, md5 digest.
You can use this function for it:

<?php

function md5bin( $target ) {
   
$md5 = md5( $target );
   
$ret = '';

    for (
$i = 0; $i < 32; $i += 2 ) {
       
$ret .= chr( hexdec( $md5{ $i + 1 } ) + hexdec( $md5{ $i } ) * 16 );
    }

    return
$ret;
}

?>
up
5
Shane Allen
11 years ago
From the documentation on Digest::MD5:
md5($data,...)
This function will concatenate all arguments, calculate the MD5 digest of this "message", and return it in binary form.

md5_hex($data,...)
Same as md5(), but will return the digest in hexadecimal form.

PHP's function returns the digest in hexadecimal form, so my guess is that you're using md5() instead of md5_hex(). I have verified that md5_hex() generates the same string as PHP's md5() function.

(original comment snipped in various places)
>Hexidecimal hashes generated with Perl's Digest::MD5 module WILL
>NOT equal hashes generated with php's md5() function if the input
>text contains any non-alphanumeric characters.
>
>$phphash = md5('pa$$');
>echo "php original hash from text: $phphash";
>echo "md5 hash from perl: " . $myrow['password'];
>
>outputs:
>
>php original hash from text: 0aed5d740d7fab4201e885019a36eace
>hash from perl: c18c9c57cb3658a50de06491a70b75cd
up
3
sebastian dot haller at freesurf dot ch
7 years ago
It has been found, that hash('md5', 'string'); is faster than md5($string):

http://www.php.net/manual/en/function.hash.php
up
-1
terry _at_ scribendi_com
9 years ago
Do not use the hex strings returned by md5() as a key for MCrypt 256-bit encryption.  Hex characters only represent four bits each, so when you take 32 hex characters, you are only really using a 128-bit key, not a 256-bit one. 

Using an alphanumeric key generator [A-Za-z0-9] will also only provide a 192-bit key in 32 characters.

Two different MD5s concatenated in raw binary form, or mcrypt_create_iv(32,MCRYPT_DEV_RANDOM) will give you a true 256-bit key string.
up
-2
admin at gadelkareem dot com
6 years ago
MySQL MD() will not give you the same hash if character set is different.
ex :
<?php
#suppose table_name CHARSET=UTF8
#$md5 = md5('Städte'); # will give you a different hash than MySQL MD5()
#instead use
$md5 = md5(utf8_encode('Städte'));
$r = mysql_query("SELECT *, MD5(`word`) FROM `table_name` WHERE MD5(`word`) LIKE '{$md5}'");
if(
$r)
    while(
$row= mysql_fetch_assoc($r) )
       
print_r($row);

?>
up
-5
John
5 years ago
If you want to hash a large amount of data you can use the hash_init/hash_update/hash_final functions.

This allows you to hash chunks/parts/incremental or whatever you like to call it.
up
-8
programings at abv dot bg
1 year ago
This recursive function allow you to hash something in depth using md5().

<?php
function checksum($what, $depth = 1) {
$depth--;
if (!
$depth)
return
md5($what);
else
return
md5(checksum($what, $depth));
}
?>

The function hashed the previous hash to md5() again and again for number of times and returns the last received hash.

Example usage:

<?php
for ($i = 1; $i <= 10; $i++) {
echo
"$i. ".checksum("test", $i)."<br />";
}
?>

It can be used for security purposes.
up
-7
rahul dot giri64 at gmail dot com
8 months ago
Requested to every php programmer ,  never ever ever  use md5() to  encrypt your passwords. it's not safe.

Go for either one of them -

1)  SHA-1
2)   SHA-2(SHA-256 , SHA-512)
3) Whirlpool
4) Tiger
5) AES
6)blowfish (recommended 'it's , secure, free and easy)

I wish you safe internet life , thanks  :)
up
-13
Anonymous
3 years ago
This is not encryption..... it's only a sort of DIGEST
up
-7
rahul dot giri64 at gmail dot com
8 months ago
Requested to every php programmer ,  never ever ever  use md5() to  encrypt your passwords. it's not safe.

Go for either one of this -

1)  SHA-1
2)   SHA-2(SHA-256 , SHA-512)
3) Whirlpool
4) Tiger
5) AES
6)blowfish (recommended 'it's , secure, free and easy)

I wish you safe internet life , thanks  :)
up
-10
John S.
9 years ago
If you want to replicate CPAN Digest::MD5's function md5_base64 in PHP, use this code:

<?php

function md5_base64 ( $data )
{
    return
preg_replace('/=+$/','',base64_encode(pack('H*',md5($data))));
}

?>
up
-10
rafael59
7 months ago
<?php
$str
= "string";
echo
md5($str);
?>
up
-16
marzetti dot marco at NOSPAM dot gmail dot com
8 years ago
The complement of raw2hex

<?php

function hex2raw( $str ){
 
$chunks = str_split($str, 2);
  for(
$i = 0; $i < sizeof($chunks); $i++ ) {
       
$op .= chr( hexdec( $chunks[$i] ) );
    }
    return
$op;
}

?>
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