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</div><hr /><div id="password.constants" class="appendix">
<h1>Predefined Constants</h1>
<p class="simpara">
The constants below are always available as part of the PHP core.
</p>
<p class="para">
<dl>
<dt id="constant.password-bcrypt">
<strong><code>PASSWORD_BCRYPT</code></strong>
(<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>)
</dt>
<dd>
<p class="para">
<strong><code>PASSWORD_BCRYPT</code></strong> is used to create new password
hashes using the <strong><code>CRYPT_BLOWFISH</code></strong> algorithm.
</p>
<p class="para">
This will always result in a hash using the "$2y$" crypt format,
which is always 60 characters wide.
</p>
<p class="para">
Supported Options:
</p>
<ul class="itemizedlist">
<li class="listitem">
<p class="para">
<em>salt</em> (<span class="type"><a href="language.types.string.html" class="type string">string</a></span>) - to manually provide a salt to use when hashing the password.
Note that this will override and prevent a salt from being automatically generated.
</p>
<p class="para">
If omitted, a random salt will be generated by <span class="function"><a href="function.password-hash.html" class="function">password_hash()</a></span> for
each password hashed. This is the intended mode of operation
and as of PHP 7.0.0 the salt option has been deprecated.
</p>
</li>
<li class="listitem">
<p class="para">
<em>cost</em> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) - which denotes the algorithmic cost that
should be used. Examples of these values can be found on the <span class="function"><a href="function.crypt.html" class="function">crypt()</a></span>
page.
</p>
<p class="para">
If omitted, a default value of <em>10</em> will be used. This is a good
baseline cost, but you may want to consider increasing it depending on your hardware.
</p>
</li>
</ul>
</dd>
<dt id="constant.password-argon2i">
<strong><code>PASSWORD_ARGON2I</code></strong>
(<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>)
</dt>
<dd>
<p class="para">
<strong><code>PASSWORD_ARGON2I</code></strong> is used to create new password
hashes using the Argon2 algorithm.
</p>
<p class="para">
Supported Options:
</p>
<ul class="itemizedlist">
<li class="listitem">
<p class="para">
<em>memory_cost</em> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) - Maximum memory (in bytes) that may
be used to compute the Argon2 hash. Defaults to <strong><code>PASSWORD_ARGON2_DEFAULT_MEMORY_COST</code></strong>.
</p>
</li>
<li class="listitem">
<p class="para">
<em>time_cost</em> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) - Maximum amount of time it may
take to compute the Argon2 hash. Defaults to <strong><code>PASSWORD_ARGON2_DEFAULT_TIME_COST</code></strong>.
</p>
</li>
<li class="listitem">
<p class="para">
<em>threads</em> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) - Number of threads to use for computing
the Argon2 hash. Defaults to <strong><code>PASSWORD_ARGON2_DEFAULT_THREADS</code></strong>.
</p>
</li>
</ul>
<p class="para">
Available as of PHP 7.2.0.
</p>
</dd>
<dt id="constant.password-argon2id">
<strong><code>PASSWORD_ARGON2ID</code></strong>
(<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>)
</dt>
<dd>
<p class="para">
Available as of PHP 7.3.0.
</p>
</dd>
<dt id="constant.password-argon2-default-memory-cost">
<strong><code>PASSWORD_ARGON2_DEFAULT_MEMORY_COST</code></strong>
(<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>)
</dt>
<dd>
<p class="para">
Default amount of memory in bytes that Argon2lib will use while trying to
compute a hash.
</p>
<p class="para">
Available as of PHP 7.2.0.
</p>
</dd>
<dt id="constant.password-argon2-default-time-cost">
<strong><code>PASSWORD_ARGON2_DEFAULT_TIME_COST</code></strong>
(<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>)
</dt>
<dd>
<p class="para">
Default amount of time that Argon2lib will spend trying to compute a hash.
</p>
<p class="para">
Available as of PHP 7.2.0.
</p>
</dd>
<dt id="constant.password-argon2-default-threads">
<strong><code>PASSWORD_ARGON2_DEFAULT_THREADS</code></strong>
(<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>)
</dt>
<dd>
<p class="para">
Default number of threads that Argon2lib will use.
</p>
<p class="para">
Available as of PHP 7.2.0.
</p>
</dd>
<dt id="constant.password-default">
<strong><code>PASSWORD_DEFAULT</code></strong>
(<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>)
</dt>
<dd>
<p class="para">
The default algorithm to use for hashing if no algorithm is provided.
This may change in newer PHP releases when newer, stronger hashing
algorithms are supported.
</p>
<p class="para">
It is worth noting that over time this constant can (and likely will)
change. Therefore you should be aware that the length of the resulting
hash can change. Therefore, if you use <strong><code>PASSWORD_DEFAULT</code></strong>
you should store the resulting hash in a way that can store more than 60
characters (255 is the recomended width).
</p>
<p class="para">
Values for this constant:
</p>
<ul class="itemizedlist">
<li class="listitem">
<span class="simpara">
PHP 5.5.0 - <strong><code>PASSWORD_BCRYPT</code></strong>
</span>
</li>
</ul>
</dd>
</dl>
</p>
</div>
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