[#CRYPTO_gcm128_init]
= CRYPTO_gcm128_init
:mrdocs:

Initialise (or reinitialise) a caller‐owned GCM128_CONTEXT.

== Synopsis

Declared in `<openssl/modes.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
void
CRYPTO_gcm128_init(
    xref:GCM128_CONTEXT-04.adoc[GCM128_CONTEXT]* ctx,
    void* key,
    xref:block128_f.adoc[block128_f] block);
----

== Parameters

[cols="1,4"]
|===
| Name| Description
| *ctx*
| Context storage to initialise.
| *key*
| Cipher‐specific expanded key for `block.`
| *block*
| Block‐encrypt function used for GHASH key derivation and CTR.
|===


[.small]#Created with https://www.mrdocs.com[MrDocs]#