---
name: "shishi_encrypt_ivupdate_etype"
section: "3"
platform: "linux"
package: "shishi-doc"
version: "1.0.3-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/shishi_encrypt_ivupdate_etype"
---

# shishi\_encrypt\_ivupdate\_etype(3)

API function

## NAME

shishi\_encrypt\_ivupdate\_etype - API function

## SYNOPSIS

**#include \<shishi.h\>**

**int shishi\_encrypt\_ivupdate\_etype(Shishi \*** *handle***, Shishi\_key \*** *key***, int** *keyusage***, int32\_t** *etype***, const char \*** *iv***, size\_t** *ivlen***, char \*\*** *ivout***, size\_t \*** *ivoutlen***, const char \*** *in***, size\_t** *inlen***, char \*\*** *out***, size\_t \*** *outlen***);**

## ARGUMENTS

- Shishi \* handle

  shishi handle as allocated by **shishi\_init()**.

- Shishi\_key \* key

  key to encrypt with.

- int keyusage

  integer specifying what this key is encrypting.

- int32\_t etype

  integer specifying what cipher to use.

- const char \* iv

  input array with initialization vector

- size\_t ivlen

  size of input array with initialization vector.

- char \*\* ivout

  output array with newly allocated updated initialization vector.

- size\_t \* ivoutlen

  size of output array with updated initialization vector.

- const char \* in

  input array with data to encrypt.

- size\_t inlen

  size of input array with data to encrypt.

- char \*\* out

  output array with newly allocated encrypted data.

- size\_t \* outlen

  output variable with size of newly allocated output array.

## DESCRIPTION

Encrypts data as per encryption method using specified initialization vector and key.  The key actually used is derived using the key usage.  If key usage is 0, no key derivation is used. The OUT buffer must be deallocated by the caller.  If IVOUT or IVOUTLEN is NULL, the updated IV is not saved anywhere.

Note that DECRYPT(ENCRYPT(data)) does not necessarily yield data exactly.  Some encryption types add pad to make the data fit into the block size of the encryption algorithm.  Furthermore, the pad is not guaranteed to look in any special way, although existing implementations often pad with the zero byte.  This means that you may have to "frame" data, so it is possible to infer the original length after decryption.  Compare ASN.1 DER which contains such information.

## RETURN VALUE

Returns **SHISHI\_OK** iff successful.

## REPORTING BUGS

Report bugs to \<bug-shishi@gnu.org\>. GNU Shishi home page: http://www.gnu.org/software/shishi/ General help using GNU software: http://www.gnu.org/gethelp/

## COPYRIGHT

Copyright © 2002-2022 Simon Josefsson.\
 Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.

## SEE ALSO

The full documentation for **shishi** is maintained as a Texinfo manual.  If the **info** and **shishi** programs are properly installed at your site, the command

-

  **info shishi**

should give you access to the complete manual.