'\" t
.\"     Title: kcapi_cipher_stream_update_last
.\"    Author: 
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: November 2020
.\"    Manual: Programming Interface
.\"    Source: libkcapi Manual 1.2.1
.\"  Language: English
.\"
.TH "KCAPI_CIPHER_STREAM_" "3" "November 2020" "libkcapi Manual 1\&.2\&.1" "Programming Interface"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
kcapi_cipher_stream_update_last \- send last data for processing (stream)
.SH "SYNOPSIS"
.HP \w'int32_t\ kcapi_cipher_stream_update_last('u
.BI "int32_t kcapi_cipher_stream_update_last(struct\ kcapi_handle\ *\ " "handle" ", struct\ iovec\ *\ " "iov" ", uint32_t\ " "iovlen" ");"
.SH "ARGUMENTS"
.PP
\fIhandle\fR
.RS 4
[in] cipher handle
.RE
.PP
\fIiov\fR
.RS 4
[in] scatter/gather list with data to be processed by the cipher operation\&.
.RE
.PP
\fIiovlen\fR
.RS 4
[in] number of scatter/gather list elements\&.
.RE
.SH "DESCRIPTION"
.PP
Using this function call, more plaintext for encryption or ciphertext for decryption can be submitted to the kernel\&.
.PP
This call is identical to the
\fBkcapi_cipher_stream_update\fR
call with the exception that it marks the last data buffer before the cipher operation is triggered\&. This is call is important for stream ciphers like CTR or CTS mode when providing the last block\&. It is permissible to provide a zero buffer if all data including the last block is already provided by kcapi_cipher_stream_update\&.
.SH "WARNING"
.PP
If this call is not made for stream ciphers with input data that is not a multiple of the block size of the block cipher, the kernel will not return the last block that contains less data than the block size of the block cipher\&. For example, sending 257 bytes of data to be encrypted with ctr(aes), the kernel will return only 256 bytes without this call\&.
.PP
\fIreturn\fR
number of bytes sent to the kernel upon success; a negative errno\-style error code if an error occurred
.SH "AUTHOR"
.PP
\fBStephan Mueller\fR <\&smueller@chronox.de\&>
.RS 4
Author.
.RE
.SH "COPYRIGHT"
.br