'\" t
.\"     Title: struct ablkcipher_alg
.\"    Author: 
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: April 2019
.\"    Manual: Programming Interface
.\"    Source: Kernel Hackers Manual 4.9.168
.\"  Language: English
.\"
.TH "STRUCT ABLKCIPHER_AL" "9" "April 2019" "Kernel Hackers Manual 4\&.9\&." "Programming Interface"
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.SH "NAME"
struct_ablkcipher_alg \- asynchronous block cipher definition
.SH "SYNOPSIS"
.sp
.nf
struct ablkcipher_alg {
  int (* setkey) (struct crypto_ablkcipher *tfm, const u8 *key,unsigned int keylen);
  int (* encrypt) (struct ablkcipher_request *req);
  int (* decrypt) (struct ablkcipher_request *req);
  int (* givencrypt) (struct skcipher_givcrypt_request *req);
  int (* givdecrypt) (struct skcipher_givcrypt_request *req);
  const char * geniv;
  unsigned int min_keysize;
  unsigned int max_keysize;
  unsigned int ivsize;
};  
.fi
.SH "MEMBERS"
.PP
setkey
.RS 4
Set key for the transformation\&. This function is used to either program a supplied key into the hardware or store the key in the transformation context for programming it later\&. Note that this function does modify the transformation context\&. This function can be called multiple times during the existence of the transformation object, so one must make sure the key is properly reprogrammed into the hardware\&. This function is also responsible for checking the key length for validity\&. In case a software fallback was put in place in the
\fIcra_init\fR
call, this function might need to use the fallback if the algorithm doesn\*(Aqt support all of the key sizes\&.
.RE
.PP
encrypt
.RS 4
Encrypt a scatterlist of blocks\&. This function is used to encrypt the supplied scatterlist containing the blocks of data\&. The crypto API consumer is responsible for aligning the entries of the scatterlist properly and making sure the chunks are correctly sized\&. In case a software fallback was put in place in the
\fIcra_init\fR
call, this function might need to use the fallback if the algorithm doesn\*(Aqt support all of the key sizes\&. In case the key was stored in transformation context, the key might need to be re\-programmed into the hardware in this function\&. This function shall not modify the transformation context, as this function may be called in parallel with the same transformation object\&.
.RE
.PP
decrypt
.RS 4
Decrypt a single block\&. This is a reverse counterpart to
\fIencrypt\fR
and the conditions are exactly the same\&.
.RE
.PP
givencrypt
.RS 4
Update the IV for encryption\&. With this function, a cipher implementation may provide the function on how to update the IV for encryption\&.
.RE
.PP
givdecrypt
.RS 4
Update the IV for decryption\&. This is the reverse of
\fIgivencrypt\fR
\&.
.RE
.PP
geniv
.RS 4
The transformation implementation may use an
\(lqIV generator\(rq
provided by the kernel crypto API\&. Several use cases have a predefined approach how IVs are to be updated\&. For such use cases, the kernel crypto API provides ready\-to\-use implementations that can be referenced with this variable\&.
.RE
.PP
min_keysize
.RS 4
Minimum key size supported by the transformation\&. This is the smallest key length supported by this transformation algorithm\&. This must be set to one of the pre\-defined values as this is not hardware specific\&. Possible values for this field can be found via git grep
\(lq_MIN_KEY_SIZE\(rq
include/crypto/
.RE
.PP
max_keysize
.RS 4
Maximum key size supported by the transformation\&. This is the largest key length supported by this transformation algorithm\&. This must be set to one of the pre\-defined values as this is not hardware specific\&. Possible values for this field can be found via git grep
\(lq_MAX_KEY_SIZE\(rq
include/crypto/
.RE
.PP
ivsize
.RS 4
IV size applicable for transformation\&. The consumer must provide an IV of exactly that size to perform the encrypt or decrypt operation\&.
.RE
.SH "DESCRIPTION"
.PP
All fields except
\fIgivencrypt\fR
,
\fIgivdecrypt\fR
,
\fIgeniv\fR
and
\fIivsize\fR
are mandatory and must be filled\&.
.SH "AUTHORS"
.PP
\fBStephan Mueller\fR <\&smueller@chronox.de\&>
.RS 4
Author.
.RE
.PP
\fBMarek Vasut\fR <\&marek@denx.de\&>
.RS 4
Author.
.RE
.SH "COPYRIGHT"
.br