---
name: "kcapi_akcipher_stream_init_vfy"
section: "3"
platform: "linux"
package: "libkcapi-dev"
version: "1.4.0-1+b2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/kcapi_akcipher_stream_init_vfy"
---

# kcapi\_akcipher\_stream\_init\_vfy(3)

start an signature verification operation (stream)

## NAME

kcapi\_akcipher\_stream\_init\_vfy - start an signature verification operation (stream)

## SYNOPSIS

**ssize\_t kcapi\_akcipher\_stream\_init\_vfy(struct kcapi\_handle \*** *handle***, struct iovec \*** *iov***, size\_t** *iovlen***);**

## ARGUMENTS

*handle*

\[in\] cipher handle

*iov*

\[in\] scatter/gather list with data to be verified. This is the pointer to the first iov entry if an array of iov entries is supplied. See [sendmsg(2)](/sendmsg/2.md) for details on how iov is to be used. This pointer may be NULL if no data to be verified is available at the point of the call.

*iovlen*

\[in\] number of scatter/gather list elements. If iov is NULL, this value must be zero.

## DESCRIPTION

A stream signature verification operation is started with this call. Multiple successive **kcapi\_akcipher\_stream\_update** function calls can be invoked to send more plaintext data to be verified. The last invocation to supply data must be done with **kcapi\_akcipher\_stream\_update\_last**. The kernel buffers the input until **kcapi\_akcipher\_stream\_op** picks up the verified data. Once plaintext is verified during the **kcapi\_cipher\_stream\_op** it is removed from the kernel buffer.

The function calls of **kcapi\_akcipher\_stream\_update** and **kcapi\_akcipher\_stream\_op** can be mixed, even by multiple threads of an application.

*return* number of bytes sent to the kernel upon success; a negative errno-style error code if an error occurred

## AUTHOR

**Stephan Mueller** \<smueller@chronox.de\>

Author.

## COPYRIGHT