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       1                 :            : /* SPDX-License-Identifier: GPL-2.0-or-later */
       2                 :            : /*
       3                 :            :  * AEAD: Authenticated Encryption with Associated Data
       4                 :            :  * 
       5                 :            :  * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
       6                 :            :  */
       7                 :            : 
       8                 :            : #ifndef _CRYPTO_AEAD_H
       9                 :            : #define _CRYPTO_AEAD_H
      10                 :            : 
      11                 :            : #include <linux/crypto.h>
      12                 :            : #include <linux/kernel.h>
      13                 :            : #include <linux/slab.h>
      14                 :            : 
      15                 :            : /**
      16                 :            :  * DOC: Authenticated Encryption With Associated Data (AEAD) Cipher API
      17                 :            :  *
      18                 :            :  * The AEAD cipher API is used with the ciphers of type CRYPTO_ALG_TYPE_AEAD
      19                 :            :  * (listed as type "aead" in /proc/crypto)
      20                 :            :  *
      21                 :            :  * The most prominent examples for this type of encryption is GCM and CCM.
      22                 :            :  * However, the kernel supports other types of AEAD ciphers which are defined
      23                 :            :  * with the following cipher string:
      24                 :            :  *
      25                 :            :  *      authenc(keyed message digest, block cipher)
      26                 :            :  *
      27                 :            :  * For example: authenc(hmac(sha256), cbc(aes))
      28                 :            :  *
      29                 :            :  * The example code provided for the symmetric key cipher operation
      30                 :            :  * applies here as well. Naturally all *skcipher* symbols must be exchanged
      31                 :            :  * the *aead* pendants discussed in the following. In addition, for the AEAD
      32                 :            :  * operation, the aead_request_set_ad function must be used to set the
      33                 :            :  * pointer to the associated data memory location before performing the
      34                 :            :  * encryption or decryption operation. In case of an encryption, the associated
      35                 :            :  * data memory is filled during the encryption operation. For decryption, the
      36                 :            :  * associated data memory must contain data that is used to verify the integrity
      37                 :            :  * of the decrypted data. Another deviation from the asynchronous block cipher
      38                 :            :  * operation is that the caller should explicitly check for -EBADMSG of the
      39                 :            :  * crypto_aead_decrypt. That error indicates an authentication error, i.e.
      40                 :            :  * a breach in the integrity of the message. In essence, that -EBADMSG error
      41                 :            :  * code is the key bonus an AEAD cipher has over "standard" block chaining
      42                 :            :  * modes.
      43                 :            :  *
      44                 :            :  * Memory Structure:
      45                 :            :  *
      46                 :            :  * To support the needs of the most prominent user of AEAD ciphers, namely
      47                 :            :  * IPSEC, the AEAD ciphers have a special memory layout the caller must adhere
      48                 :            :  * to.
      49                 :            :  *
      50                 :            :  * The scatter list pointing to the input data must contain:
      51                 :            :  *
      52                 :            :  * * for RFC4106 ciphers, the concatenation of
      53                 :            :  *   associated authentication data || IV || plaintext or ciphertext. Note, the
      54                 :            :  *   same IV (buffer) is also set with the aead_request_set_crypt call. Note,
      55                 :            :  *   the API call of aead_request_set_ad must provide the length of the AAD and
      56                 :            :  *   the IV. The API call of aead_request_set_crypt only points to the size of
      57                 :            :  *   the input plaintext or ciphertext.
      58                 :            :  *
      59                 :            :  * * for "normal" AEAD ciphers, the concatenation of
      60                 :            :  *   associated authentication data || plaintext or ciphertext.
      61                 :            :  *
      62                 :            :  * It is important to note that if multiple scatter gather list entries form
      63                 :            :  * the input data mentioned above, the first entry must not point to a NULL
      64                 :            :  * buffer. If there is any potential where the AAD buffer can be NULL, the
      65                 :            :  * calling code must contain a precaution to ensure that this does not result
      66                 :            :  * in the first scatter gather list entry pointing to a NULL buffer.
      67                 :            :  */
      68                 :            : 
      69                 :            : struct crypto_aead;
      70                 :            : 
      71                 :            : /**
      72                 :            :  *      struct aead_request - AEAD request
      73                 :            :  *      @base: Common attributes for async crypto requests
      74                 :            :  *      @assoclen: Length in bytes of associated data for authentication
      75                 :            :  *      @cryptlen: Length of data to be encrypted or decrypted
      76                 :            :  *      @iv: Initialisation vector
      77                 :            :  *      @src: Source data
      78                 :            :  *      @dst: Destination data
      79                 :            :  *      @__ctx: Start of private context data
      80                 :            :  */
      81                 :            : struct aead_request {
      82                 :            :         struct crypto_async_request base;
      83                 :            : 
      84                 :            :         unsigned int assoclen;
      85                 :            :         unsigned int cryptlen;
      86                 :            : 
      87                 :            :         u8 *iv;
      88                 :            : 
      89                 :            :         struct scatterlist *src;
      90                 :            :         struct scatterlist *dst;
      91                 :            : 
      92                 :            :         void *__ctx[] CRYPTO_MINALIGN_ATTR;
      93                 :            : };
      94                 :            : 
      95                 :            : /**
      96                 :            :  * struct aead_alg - AEAD cipher definition
      97                 :            :  * @maxauthsize: Set the maximum authentication tag size supported by the
      98                 :            :  *               transformation. A transformation may support smaller tag sizes.
      99                 :            :  *               As the authentication tag is a message digest to ensure the
     100                 :            :  *               integrity of the encrypted data, a consumer typically wants the
     101                 :            :  *               largest authentication tag possible as defined by this
     102                 :            :  *               variable.
     103                 :            :  * @setauthsize: Set authentication size for the AEAD transformation. This
     104                 :            :  *               function is used to specify the consumer requested size of the
     105                 :            :  *               authentication tag to be either generated by the transformation
     106                 :            :  *               during encryption or the size of the authentication tag to be
     107                 :            :  *               supplied during the decryption operation. This function is also
     108                 :            :  *               responsible for checking the authentication tag size for
     109                 :            :  *               validity.
     110                 :            :  * @setkey: see struct skcipher_alg
     111                 :            :  * @encrypt: see struct skcipher_alg
     112                 :            :  * @decrypt: see struct skcipher_alg
     113                 :            :  * @ivsize: see struct skcipher_alg
     114                 :            :  * @chunksize: see struct skcipher_alg
     115                 :            :  * @init: Initialize the cryptographic transformation object. This function
     116                 :            :  *        is used to initialize the cryptographic transformation object.
     117                 :            :  *        This function is called only once at the instantiation time, right
     118                 :            :  *        after the transformation context was allocated. In case the
     119                 :            :  *        cryptographic hardware has some special requirements which need to
     120                 :            :  *        be handled by software, this function shall check for the precise
     121                 :            :  *        requirement of the transformation and put any software fallbacks
     122                 :            :  *        in place.
     123                 :            :  * @exit: Deinitialize the cryptographic transformation object. This is a
     124                 :            :  *        counterpart to @init, used to remove various changes set in
     125                 :            :  *        @init.
     126                 :            :  * @base: Definition of a generic crypto cipher algorithm.
     127                 :            :  *
     128                 :            :  * All fields except @ivsize is mandatory and must be filled.
     129                 :            :  */
     130                 :            : struct aead_alg {
     131                 :            :         int (*setkey)(struct crypto_aead *tfm, const u8 *key,
     132                 :            :                       unsigned int keylen);
     133                 :            :         int (*setauthsize)(struct crypto_aead *tfm, unsigned int authsize);
     134                 :            :         int (*encrypt)(struct aead_request *req);
     135                 :            :         int (*decrypt)(struct aead_request *req);
     136                 :            :         int (*init)(struct crypto_aead *tfm);
     137                 :            :         void (*exit)(struct crypto_aead *tfm);
     138                 :            : 
     139                 :            :         unsigned int ivsize;
     140                 :            :         unsigned int maxauthsize;
     141                 :            :         unsigned int chunksize;
     142                 :            : 
     143                 :            :         struct crypto_alg base;
     144                 :            : };
     145                 :            : 
     146                 :            : struct crypto_aead {
     147                 :            :         unsigned int authsize;
     148                 :            :         unsigned int reqsize;
     149                 :            : 
     150                 :            :         struct crypto_tfm base;
     151                 :            : };
     152                 :            : 
     153                 :            : static inline struct crypto_aead *__crypto_aead_cast(struct crypto_tfm *tfm)
     154                 :            : {
     155                 :          0 :         return container_of(tfm, struct crypto_aead, base);
     156                 :            : }
     157                 :            : 
     158                 :            : /**
     159                 :            :  * crypto_alloc_aead() - allocate AEAD cipher handle
     160                 :            :  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
     161                 :            :  *           AEAD cipher
     162                 :            :  * @type: specifies the type of the cipher
     163                 :            :  * @mask: specifies the mask for the cipher
     164                 :            :  *
     165                 :            :  * Allocate a cipher handle for an AEAD. The returned struct
     166                 :            :  * crypto_aead is the cipher handle that is required for any subsequent
     167                 :            :  * API invocation for that AEAD.
     168                 :            :  *
     169                 :            :  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
     170                 :            :  *         of an error, PTR_ERR() returns the error code.
     171                 :            :  */
     172                 :            : struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask);
     173                 :            : 
     174                 :            : static inline struct crypto_tfm *crypto_aead_tfm(struct crypto_aead *tfm)
     175                 :            : {
     176                 :          0 :         return &tfm->base;
     177                 :            : }
     178                 :            : 
     179                 :            : /**
     180                 :            :  * crypto_free_aead() - zeroize and free aead handle
     181                 :            :  * @tfm: cipher handle to be freed
     182                 :            :  */
     183                 :            : static inline void crypto_free_aead(struct crypto_aead *tfm)
     184                 :            : {
     185                 :          0 :         crypto_destroy_tfm(tfm, crypto_aead_tfm(tfm));
     186                 :            : }
     187                 :            : 
     188                 :            : static inline struct aead_alg *crypto_aead_alg(struct crypto_aead *tfm)
     189                 :            : {
     190                 :          0 :         return container_of(crypto_aead_tfm(tfm)->__crt_alg,
     191                 :            :                             struct aead_alg, base);
     192                 :            : }
     193                 :            : 
     194                 :            : static inline unsigned int crypto_aead_alg_ivsize(struct aead_alg *alg)
     195                 :            : {
     196                 :          0 :         return alg->ivsize;
     197                 :            : }
     198                 :            : 
     199                 :            : /**
     200                 :            :  * crypto_aead_ivsize() - obtain IV size
     201                 :            :  * @tfm: cipher handle
     202                 :            :  *
     203                 :            :  * The size of the IV for the aead referenced by the cipher handle is
     204                 :            :  * returned. This IV size may be zero if the cipher does not need an IV.
     205                 :            :  *
     206                 :            :  * Return: IV size in bytes
     207                 :            :  */
     208                 :            : static inline unsigned int crypto_aead_ivsize(struct crypto_aead *tfm)
     209                 :            : {
     210                 :            :         return crypto_aead_alg_ivsize(crypto_aead_alg(tfm));
     211                 :            : }
     212                 :            : 
     213                 :            : /**
     214                 :            :  * crypto_aead_authsize() - obtain maximum authentication data size
     215                 :            :  * @tfm: cipher handle
     216                 :            :  *
     217                 :            :  * The maximum size of the authentication data for the AEAD cipher referenced
     218                 :            :  * by the AEAD cipher handle is returned. The authentication data size may be
     219                 :            :  * zero if the cipher implements a hard-coded maximum.
     220                 :            :  *
     221                 :            :  * The authentication data may also be known as "tag value".
     222                 :            :  *
     223                 :            :  * Return: authentication data size / tag size in bytes
     224                 :            :  */
     225                 :            : static inline unsigned int crypto_aead_authsize(struct crypto_aead *tfm)
     226                 :            : {
     227                 :          0 :         return tfm->authsize;
     228                 :            : }
     229                 :            : 
     230                 :            : /**
     231                 :            :  * crypto_aead_blocksize() - obtain block size of cipher
     232                 :            :  * @tfm: cipher handle
     233                 :            :  *
     234                 :            :  * The block size for the AEAD referenced with the cipher handle is returned.
     235                 :            :  * The caller may use that information to allocate appropriate memory for the
     236                 :            :  * data returned by the encryption or decryption operation
     237                 :            :  *
     238                 :            :  * Return: block size of cipher
     239                 :            :  */
     240                 :            : static inline unsigned int crypto_aead_blocksize(struct crypto_aead *tfm)
     241                 :            : {
     242                 :            :         return crypto_tfm_alg_blocksize(crypto_aead_tfm(tfm));
     243                 :            : }
     244                 :            : 
     245                 :            : static inline unsigned int crypto_aead_alignmask(struct crypto_aead *tfm)
     246                 :            : {
     247                 :            :         return crypto_tfm_alg_alignmask(crypto_aead_tfm(tfm));
     248                 :            : }
     249                 :            : 
     250                 :            : static inline u32 crypto_aead_get_flags(struct crypto_aead *tfm)
     251                 :            : {
     252                 :            :         return crypto_tfm_get_flags(crypto_aead_tfm(tfm));
     253                 :            : }
     254                 :            : 
     255                 :            : static inline void crypto_aead_set_flags(struct crypto_aead *tfm, u32 flags)
     256                 :            : {
     257                 :            :         crypto_tfm_set_flags(crypto_aead_tfm(tfm), flags);
     258                 :            : }
     259                 :            : 
     260                 :            : static inline void crypto_aead_clear_flags(struct crypto_aead *tfm, u32 flags)
     261                 :            : {
     262                 :            :         crypto_tfm_clear_flags(crypto_aead_tfm(tfm), flags);
     263                 :            : }
     264                 :            : 
     265                 :            : /**
     266                 :            :  * crypto_aead_setkey() - set key for cipher
     267                 :            :  * @tfm: cipher handle
     268                 :            :  * @key: buffer holding the key
     269                 :            :  * @keylen: length of the key in bytes
     270                 :            :  *
     271                 :            :  * The caller provided key is set for the AEAD referenced by the cipher
     272                 :            :  * handle.
     273                 :            :  *
     274                 :            :  * Note, the key length determines the cipher type. Many block ciphers implement
     275                 :            :  * different cipher modes depending on the key size, such as AES-128 vs AES-192
     276                 :            :  * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
     277                 :            :  * is performed.
     278                 :            :  *
     279                 :            :  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
     280                 :            :  */
     281                 :            : int crypto_aead_setkey(struct crypto_aead *tfm,
     282                 :            :                        const u8 *key, unsigned int keylen);
     283                 :            : 
     284                 :            : /**
     285                 :            :  * crypto_aead_setauthsize() - set authentication data size
     286                 :            :  * @tfm: cipher handle
     287                 :            :  * @authsize: size of the authentication data / tag in bytes
     288                 :            :  *
     289                 :            :  * Set the authentication data size / tag size. AEAD requires an authentication
     290                 :            :  * tag (or MAC) in addition to the associated data.
     291                 :            :  *
     292                 :            :  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
     293                 :            :  */
     294                 :            : int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize);
     295                 :            : 
     296                 :            : static inline struct crypto_aead *crypto_aead_reqtfm(struct aead_request *req)
     297                 :            : {
     298                 :          0 :         return __crypto_aead_cast(req->base.tfm);
     299                 :            : }
     300                 :            : 
     301                 :            : /**
     302                 :            :  * crypto_aead_encrypt() - encrypt plaintext
     303                 :            :  * @req: reference to the aead_request handle that holds all information
     304                 :            :  *       needed to perform the cipher operation
     305                 :            :  *
     306                 :            :  * Encrypt plaintext data using the aead_request handle. That data structure
     307                 :            :  * and how it is filled with data is discussed with the aead_request_*
     308                 :            :  * functions.
     309                 :            :  *
     310                 :            :  * IMPORTANT NOTE The encryption operation creates the authentication data /
     311                 :            :  *                tag. That data is concatenated with the created ciphertext.
     312                 :            :  *                The ciphertext memory size is therefore the given number of
     313                 :            :  *                block cipher blocks + the size defined by the
     314                 :            :  *                crypto_aead_setauthsize invocation. The caller must ensure
     315                 :            :  *                that sufficient memory is available for the ciphertext and
     316                 :            :  *                the authentication tag.
     317                 :            :  *
     318                 :            :  * Return: 0 if the cipher operation was successful; < 0 if an error occurred
     319                 :            :  */
     320                 :            : int crypto_aead_encrypt(struct aead_request *req);
     321                 :            : 
     322                 :            : /**
     323                 :            :  * crypto_aead_decrypt() - decrypt ciphertext
     324                 :            :  * @req: reference to the ablkcipher_request handle that holds all information
     325                 :            :  *       needed to perform the cipher operation
     326                 :            :  *
     327                 :            :  * Decrypt ciphertext data using the aead_request handle. That data structure
     328                 :            :  * and how it is filled with data is discussed with the aead_request_*
     329                 :            :  * functions.
     330                 :            :  *
     331                 :            :  * IMPORTANT NOTE The caller must concatenate the ciphertext followed by the
     332                 :            :  *                authentication data / tag. That authentication data / tag
     333                 :            :  *                must have the size defined by the crypto_aead_setauthsize
     334                 :            :  *                invocation.
     335                 :            :  *
     336                 :            :  *
     337                 :            :  * Return: 0 if the cipher operation was successful; -EBADMSG: The AEAD
     338                 :            :  *         cipher operation performs the authentication of the data during the
     339                 :            :  *         decryption operation. Therefore, the function returns this error if
     340                 :            :  *         the authentication of the ciphertext was unsuccessful (i.e. the
     341                 :            :  *         integrity of the ciphertext or the associated data was violated);
     342                 :            :  *         < 0 if an error occurred.
     343                 :            :  */
     344                 :            : int crypto_aead_decrypt(struct aead_request *req);
     345                 :            : 
     346                 :            : /**
     347                 :            :  * DOC: Asynchronous AEAD Request Handle
     348                 :            :  *
     349                 :            :  * The aead_request data structure contains all pointers to data required for
     350                 :            :  * the AEAD cipher operation. This includes the cipher handle (which can be
     351                 :            :  * used by multiple aead_request instances), pointer to plaintext and
     352                 :            :  * ciphertext, asynchronous callback function, etc. It acts as a handle to the
     353                 :            :  * aead_request_* API calls in a similar way as AEAD handle to the
     354                 :            :  * crypto_aead_* API calls.
     355                 :            :  */
     356                 :            : 
     357                 :            : /**
     358                 :            :  * crypto_aead_reqsize() - obtain size of the request data structure
     359                 :            :  * @tfm: cipher handle
     360                 :            :  *
     361                 :            :  * Return: number of bytes
     362                 :            :  */
     363                 :            : static inline unsigned int crypto_aead_reqsize(struct crypto_aead *tfm)
     364                 :            : {
     365                 :          0 :         return tfm->reqsize;
     366                 :            : }
     367                 :            : 
     368                 :            : /**
     369                 :            :  * aead_request_set_tfm() - update cipher handle reference in request
     370                 :            :  * @req: request handle to be modified
     371                 :            :  * @tfm: cipher handle that shall be added to the request handle
     372                 :            :  *
     373                 :            :  * Allow the caller to replace the existing aead handle in the request
     374                 :            :  * data structure with a different one.
     375                 :            :  */
     376                 :            : static inline void aead_request_set_tfm(struct aead_request *req,
     377                 :            :                                         struct crypto_aead *tfm)
     378                 :            : {
     379                 :            :         req->base.tfm = crypto_aead_tfm(tfm);
     380                 :            : }
     381                 :            : 
     382                 :            : /**
     383                 :            :  * aead_request_alloc() - allocate request data structure
     384                 :            :  * @tfm: cipher handle to be registered with the request
     385                 :            :  * @gfp: memory allocation flag that is handed to kmalloc by the API call.
     386                 :            :  *
     387                 :            :  * Allocate the request data structure that must be used with the AEAD
     388                 :            :  * encrypt and decrypt API calls. During the allocation, the provided aead
     389                 :            :  * handle is registered in the request data structure.
     390                 :            :  *
     391                 :            :  * Return: allocated request handle in case of success, or NULL if out of memory
     392                 :            :  */
     393                 :            : static inline struct aead_request *aead_request_alloc(struct crypto_aead *tfm,
     394                 :            :                                                       gfp_t gfp)
     395                 :            : {
     396                 :            :         struct aead_request *req;
     397                 :            : 
     398                 :            :         req = kmalloc(sizeof(*req) + crypto_aead_reqsize(tfm), gfp);
     399                 :            : 
     400                 :            :         if (likely(req))
     401                 :            :                 aead_request_set_tfm(req, tfm);
     402                 :            : 
     403                 :            :         return req;
     404                 :            : }
     405                 :            : 
     406                 :            : /**
     407                 :            :  * aead_request_free() - zeroize and free request data structure
     408                 :            :  * @req: request data structure cipher handle to be freed
     409                 :            :  */
     410                 :            : static inline void aead_request_free(struct aead_request *req)
     411                 :            : {
     412                 :            :         kzfree(req);
     413                 :            : }
     414                 :            : 
     415                 :            : /**
     416                 :            :  * aead_request_set_callback() - set asynchronous callback function
     417                 :            :  * @req: request handle
     418                 :            :  * @flags: specify zero or an ORing of the flags
     419                 :            :  *         CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
     420                 :            :  *         increase the wait queue beyond the initial maximum size;
     421                 :            :  *         CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
     422                 :            :  * @compl: callback function pointer to be registered with the request handle
     423                 :            :  * @data: The data pointer refers to memory that is not used by the kernel
     424                 :            :  *        crypto API, but provided to the callback function for it to use. Here,
     425                 :            :  *        the caller can provide a reference to memory the callback function can
     426                 :            :  *        operate on. As the callback function is invoked asynchronously to the
     427                 :            :  *        related functionality, it may need to access data structures of the
     428                 :            :  *        related functionality which can be referenced using this pointer. The
     429                 :            :  *        callback function can access the memory via the "data" field in the
     430                 :            :  *        crypto_async_request data structure provided to the callback function.
     431                 :            :  *
     432                 :            :  * Setting the callback function that is triggered once the cipher operation
     433                 :            :  * completes
     434                 :            :  *
     435                 :            :  * The callback function is registered with the aead_request handle and
     436                 :            :  * must comply with the following template::
     437                 :            :  *
     438                 :            :  *      void callback_function(struct crypto_async_request *req, int error)
     439                 :            :  */
     440                 :            : static inline void aead_request_set_callback(struct aead_request *req,
     441                 :            :                                              u32 flags,
     442                 :            :                                              crypto_completion_t compl,
     443                 :            :                                              void *data)
     444                 :            : {
     445                 :            :         req->base.complete = compl;
     446                 :            :         req->base.data = data;
     447                 :            :         req->base.flags = flags;
     448                 :            : }
     449                 :            : 
     450                 :            : /**
     451                 :            :  * aead_request_set_crypt - set data buffers
     452                 :            :  * @req: request handle
     453                 :            :  * @src: source scatter / gather list
     454                 :            :  * @dst: destination scatter / gather list
     455                 :            :  * @cryptlen: number of bytes to process from @src
     456                 :            :  * @iv: IV for the cipher operation which must comply with the IV size defined
     457                 :            :  *      by crypto_aead_ivsize()
     458                 :            :  *
     459                 :            :  * Setting the source data and destination data scatter / gather lists which
     460                 :            :  * hold the associated data concatenated with the plaintext or ciphertext. See
     461                 :            :  * below for the authentication tag.
     462                 :            :  *
     463                 :            :  * For encryption, the source is treated as the plaintext and the
     464                 :            :  * destination is the ciphertext. For a decryption operation, the use is
     465                 :            :  * reversed - the source is the ciphertext and the destination is the plaintext.
     466                 :            :  *
     467                 :            :  * The memory structure for cipher operation has the following structure:
     468                 :            :  *
     469                 :            :  * - AEAD encryption input:  assoc data || plaintext
     470                 :            :  * - AEAD encryption output: assoc data || cipherntext || auth tag
     471                 :            :  * - AEAD decryption input:  assoc data || ciphertext || auth tag
     472                 :            :  * - AEAD decryption output: assoc data || plaintext
     473                 :            :  *
     474                 :            :  * Albeit the kernel requires the presence of the AAD buffer, however,
     475                 :            :  * the kernel does not fill the AAD buffer in the output case. If the
     476                 :            :  * caller wants to have that data buffer filled, the caller must either
     477                 :            :  * use an in-place cipher operation (i.e. same memory location for
     478                 :            :  * input/output memory location).
     479                 :            :  */
     480                 :            : static inline void aead_request_set_crypt(struct aead_request *req,
     481                 :            :                                           struct scatterlist *src,
     482                 :            :                                           struct scatterlist *dst,
     483                 :            :                                           unsigned int cryptlen, u8 *iv)
     484                 :            : {
     485                 :            :         req->src = src;
     486                 :            :         req->dst = dst;
     487                 :            :         req->cryptlen = cryptlen;
     488                 :            :         req->iv = iv;
     489                 :            : }
     490                 :            : 
     491                 :            : /**
     492                 :            :  * aead_request_set_ad - set associated data information
     493                 :            :  * @req: request handle
     494                 :            :  * @assoclen: number of bytes in associated data
     495                 :            :  *
     496                 :            :  * Setting the AD information.  This function sets the length of
     497                 :            :  * the associated data.
     498                 :            :  */
     499                 :            : static inline void aead_request_set_ad(struct aead_request *req,
     500                 :            :                                        unsigned int assoclen)
     501                 :            : {
     502                 :            :         req->assoclen = assoclen;
     503                 :            : }
     504                 :            : 
     505                 :            : #endif  /* _CRYPTO_AEAD_H */