[#EVP_PKEY_CTX_ctrl_uint64]
= EVP&lowbar;PKEY&lowbar;CTX&lowbar;ctrl&lowbar;uint64
:mrdocs:

Send a control command with a uint64&lowbar;t argument to a key context&period;

== Synopsis

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

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
int
EVP&lowbar;PKEY&lowbar;CTX&lowbar;ctrl&lowbar;uint64(
    xref:EVP_PKEY_CTX.adoc[EVP&lowbar;PKEY&lowbar;CTX]* ctx,
    int keytype,
    int optype,
    int cmd,
    uint64&lowbar;t value);
----

== Return Value

Positive value on success, or a non&hyphen;positive value on failure &sol; unsupported command&period;

== Parameters

[cols="1,4"]
|===
| Name| Description
| *ctx*
| Key context receiving the command&period;
| *keytype*
| Expected key type, or &hyphen;1 to skip the type check&period;
| *optype*
| Expected operation type, or &hyphen;1 to skip the operation check&period;
| *cmd*
| Algorithm&hyphen;specific control command&period;
| *value*
| 64&hyphen;bit integer argument for `cmd&period;`
|===


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