sodium_crypto_pwhash_str

(PHP 7 >= 7.2.0, PHP 8)

sodium_crypto_pwhash_str — Get an ASCII-encoded hash

Description

sodium_crypto_pwhash_str(string $password, int $opslimit, int $memlimit): string

Uses a CPU- and memory-hard hash algorithm along with a randomly-generated salt, and memory and CPU limits to generate an ASCII-encoded hash suitable for password storage.

Parameters

password

string; The password to generate a hash for.

opslimit

Represents a maximum amount of computations to perform. Raising this number will make the function require more CPU cycles to compute a key. There are constants available to set the operations limit to appropriate values depending on intended use, in order of strength: SODIUM_CRYPTO_PWHASH_OPSLIMIT_INTERACTIVE, SODIUM_CRYPTO_PWHASH_OPSLIMIT_MODERATE and SODIUM_CRYPTO_PWHASH_OPSLIMIT_SENSITIVE.

memlimit

The maximum amount of RAM that the function will use, in bytes. There are constants to help you choose an appropriate value, in order of size: SODIUM_CRYPTO_PWHASH_MEMLIMIT_INTERACTIVE, SODIUM_CRYPTO_PWHASH_MEMLIMIT_MODERATE, and SODIUM_CRYPTO_PWHASH_MEMLIMIT_SENSITIVE. Typically these should be paired with the matching opslimit values.

Return Values

Returns the hashed password.

In order to produce the same password hash from the same password, the same values for opslimit and memlimit must be used. These are embedded within the generated hash, so everything that's needed to verify the hash is included. This allows the sodium_crypto_pwhash_str_verify() function to verify the hash without needing separate storage for the other parameters.

Examples

Example #1 sodium_crypto_pwhash_str() example

<?php
$password = 'password';
echo sodium_crypto_pwhash_str(
    $password,
    SODIUM_CRYPTO_PWHASH_OPSLIMIT_INTERACTIVE,
    SODIUM_CRYPTO_PWHASH_MEMLIMIT_INTERACTIVE
);

The above example will output something similar to:

$argon2id$v=19$m=65536,t=2,p=1$oWIfdaXwWwhVmovOBc2NAQ$EbsZ+JnZyyavkafS0hoc4HdaOB0ILWZESAZ7kVGa+Iw

Notes

Note:

Hashes are calculated using the Argon2ID algorithm, providing resistance to both GPU and side-channel attacks. In contrast to the password_hash() function, there is no salt parameter (a salt is generated automatically), and the opslimit and memlimit parameters are not optional.

See Also