AEAD_REQUEST_SET_CRY(9)               Programming Interface               AEAD_REQUEST_SET_CRY(9)



NAME
       aead_request_set_crypt - set data buffers

SYNOPSIS
       void aead_request_set_crypt(struct aead_request * req, struct scatterlist * src,
                                   struct scatterlist * dst, unsigned int cryptlen, u8 * iv);

ARGUMENTS
       req
           request handle

       src
           source scatter / gather list

       dst
           destination scatter / gather list

       cryptlen
           number of bytes to process from src

       iv
           IV for the cipher operation which must comply with the IV size defined by
           crypto_aead_ivsize

DESCRIPTION
       Setting the source data and destination data scatter / gather lists which hold the
       associated data concatenated with the plaintext or ciphertext. See below for the
       authentication tag.

       For encryption, the source is treated as the plaintext and the destination is the
       ciphertext. For a decryption operation, the use is reversed - the source is the ciphertext
       and the destination is the plaintext.

       For both src/dst the layout is associated data, plain/cipher text, authentication tag.

       The content of the AD in the destination buffer after processing will either be untouched,
       or it will contain a copy of the AD from the source buffer. In order to ensure that it
       always has a copy of the AD, the user must copy the AD over either before or after
       processing. Of course this is not relevant if the user is doing in-place processing where
       src == dst.

       IMPORTANT NOTE AEAD requires an authentication tag (MAC). For decryption, the caller must
       concatenate the ciphertext followed by the authentication tag and provide the entire data
       stream to the decryption operation (i.e. the data length used for the initialization of
       the scatterlist and the data length for the decryption operation is identical). For
       encryption, however, the authentication tag is created while encrypting the data. The
       destination buffer must hold sufficient space for the ciphertext and the authentication
       tag while the encryption invocation must only point to the plaintext data size. The
       following code snippet illustrates the memory usage buffer = kmalloc(ptbuflen + (enc ?
       authsize : 0)); sg_init_one(sg, buffer, ptbuflen + (enc ? authsize : 0));
       aead_request_set_crypt(req, sg, sg, ptbuflen, iv);

AUTHORS
       Stephan Mueller <smueller AT chronox.de>
           Author.

       Marek Vasut <marek AT denx.de>
           Author.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                   AEAD_REQUEST_SET_CRY(9)