[#EVP_EncryptInit]
= EVP_EncryptInit
:mrdocs:

Initialize `ctx` for encryption with `cipher,` `key,` and `iv.`

== Synopsis

Declared in `<openssl/evp.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
int
EVP_EncryptInit(
    xref:EVP_CIPHER_CTX.adoc[EVP_CIPHER_CTX]* ctx,
    xref:EVP_CIPHER-07.adoc[EVP_CIPHER] const* cipher,
    unsigned char const* key,
    unsigned char const* iv);
----

== Return Value

1 on success, or 0 on failure.

== Parameters

[cols="1,4"]
|===
| Name| Description
| *ctx*
| Cipher context to initialize (must already be allocated).
| *cipher*
| Cipher algorithm, or NULL to reuse the previous cipher while setting a new key/IV.
| *key*
| Encryption key bytes, or NULL to set the cipher without a key yet.
| *iv*
| Initialization vector, or NULL when the cipher does not use an IV or the IV is set later.
|===


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