---
name: "kcapi_aead_decrypt_aio"
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_aead_decrypt_aio"
---

# kcapi\_aead\_decrypt\_aio(3)

asynchronously decrypt AEAD data (one shot)

## NAME

kcapi\_aead\_decrypt\_aio - asynchronously decrypt AEAD data (one shot)

## SYNOPSIS

**ssize\_t kcapi\_aead\_decrypt\_aio(struct kcapi\_handle \*** *handle***, struct iovec \*** *iniov***, struct iovec \*** *outiov***, size\_t** *iovlen***, const uint8\_t \*** *iv***, int** *access***);**

## ARGUMENTS

*handle*

\[in\] cipher handle

*iniov*

\[in\] array of scatter-gather list with input buffers

*outiov*

\[out\] array of scatter-gather list with output buffers

*iovlen*

\[in\] number of IOVECs in array

*iv*

\[in\] IV to be used for cipher operation

*access*

\[in\] kernel access type (KCAPI\_ACCESS\_HEURISTIC - use internal heuristic for fastest kernel access; KCAPI\_ACCESS\_VMSPLICE - use vmsplice access; KCAPI\_ACCESS\_SENDMSG - sendmsg access)

## DESCRIPTION

The AEAD cipher operation requires the furnishing of the associated authentication data. In case such data is not required, it can be set to NULL and length value must be set to zero.

Each IOVEC is processed with its individual AEAD cipher operation. The memory holding the input data will receive the processed data.

The memory should be aligned at the page boundary using posix\_memalign(sysconf(\_SC\_PAGESIZE)), If it is not aligned at the page boundary, the vmsplice call may not send all data to the kernel.

The IV buffer must be exactly **kcapi\_cipher\_ivsize** bytes in size.

To catch authentication errors (i.e. integrity violations) during the decryption operation, the return value of this call should be checked. If this function returns -EBADMSG, an authentication error was detected.

## IMPORTANT NOTE

The kernel will only process sysconf(\_SC\_PAGESIZE) \* ALG\_MAX\_PAGES at one time. Longer input data cannot be handled by the kernel.

*return* number of bytes encrypted upon success; a negative errno-style error code if an error occurred

## AUTHOR

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

Author.

## COPYRIGHT