kcapi_aead_decrypt_aio - Man Page

asynchronously decrypt AEAD data (one shot)


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);



[in] cipher handle


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


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


[in] number of IOVECs in array


[in] IV to be used for cipher operation


[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)


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


Stephan Mueller <smueller@chronox.de>



July 2021 libkcapi Manual 1.3.1 Programming Interface