[#DES_is_weak_key]
= DES&lowbar;is&lowbar;weak&lowbar;key
:mrdocs:

Test whether a DES key is one of the known weak or semi&hyphen;weak keys (deprecated)&period;

== Synopsis

Declared in `&lt;openssl&sol;des&period;h&gt;`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
&lsqb;&lsqb;deprecated&rsqb;&rsqb;
int
DES&lowbar;is&lowbar;weak&lowbar;key(xref:const_DES_cblock.adoc[const&lowbar;DES&lowbar;cblock]* key);
----

[WARNING]
====
https://en.cppreference.com/cpp/language/attributes/deprecated[Deprecated^]. Use of this entity is allowed but discouraged.
====
== Return Value

1 if `key` is weak or semi&hyphen;weak, or 0 otherwise&period;

== Parameters

[cols="1,4"]
|===
| Name| Description
| *key*
| Eight&hyphen;byte DES key to check&period;
|===


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