diff options
Diffstat (limited to 'include/linux/crypto.h')
| -rw-r--r-- | include/linux/crypto.h | 1112 |
1 files changed, 1109 insertions, 3 deletions
diff --git a/include/linux/crypto.h b/include/linux/crypto.h index d45e949699ea..9c8776d0ada8 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -26,6 +26,19 @@ #include <linux/uaccess.h> /* + * Autoloaded crypto modules should only use a prefixed name to avoid allowing + * arbitrary modules to be loaded. Loading from userspace may still need the + * unprefixed names, so retains those aliases as well. + * This uses __MODULE_INFO directly instead of MODULE_ALIAS because pre-4.3 + * gcc (e.g. avr32 toolchain) uses __LINE__ for uniqueness, and this macro + * expands twice on the same line. Instead, use a separate base name for the + * alias. + */ +#define MODULE_ALIAS_CRYPTO(name) \ + __MODULE_INFO(alias, alias_userspace, name); \ + __MODULE_INFO(alias, alias_crypto, "crypto-" name) + +/* * Algorithm masks and types. */ #define CRYPTO_ALG_TYPE_MASK 0x0000000f @@ -127,6 +140,13 @@ struct skcipher_givcrypt_request; typedef void (*crypto_completion_t)(struct crypto_async_request *req, int err); +/** + * DOC: Block Cipher Context Data Structures + * + * These data structures define the operating context for each block cipher + * type. + */ + struct crypto_async_request { struct list_head list; crypto_completion_t complete; @@ -194,9 +214,63 @@ struct hash_desc { u32 flags; }; -/* - * Algorithms: modular crypto algorithm implementations, managed - * via crypto_register_alg() and crypto_unregister_alg(). +/** + * DOC: Block Cipher Algorithm Definitions + * + * These data structures define modular crypto algorithm implementations, + * managed via crypto_register_alg() and crypto_unregister_alg(). + */ + +/** + * struct ablkcipher_alg - asynchronous block cipher definition + * @min_keysize: 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 "_MIN_KEY_SIZE" include/crypto/ + * @max_keysize: 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 "_MAX_KEY_SIZE" include/crypto/ + * @setkey: 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 @cra_init call, this function might need to use the fallback if + * the algorithm doesn't support all of the key sizes. + * @encrypt: 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 + * @cra_init call, this function might need to use the fallback if + * the algorithm doesn't 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. + * @decrypt: Decrypt a single block. This is a reverse counterpart to @encrypt + * and the conditions are exactly the same. + * @givencrypt: Update the IV for encryption. With this function, a cipher + * implementation may provide the function on how to update the IV + * for encryption. + * @givdecrypt: Update the IV for decryption. This is the reverse of + * @givencrypt . + * @geniv: The transformation implementation may use an "IV generator" 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. + * @ivsize: IV size applicable for transformation. The consumer must provide an + * IV of exactly that size to perform the encrypt or decrypt operation. + * + * All fields except @givencrypt , @givdecrypt , @geniv and @ivsize are + * mandatory and must be filled. */ struct ablkcipher_alg { int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key, @@ -213,6 +287,32 @@ struct ablkcipher_alg { unsigned int ivsize; }; +/** + * struct aead_alg - AEAD cipher definition + * @maxauthsize: Set the maximum authentication tag size supported by the + * transformation. A transformation may support smaller tag sizes. + * As the authentication tag is a message digest to ensure the + * integrity of the encrypted data, a consumer typically wants the + * largest authentication tag possible as defined by this + * variable. + * @setauthsize: Set authentication size for the AEAD transformation. This + * function is used to specify the consumer requested size of the + * authentication tag to be either generated by the transformation + * during encryption or the size of the authentication tag to be + * supplied during the decryption operation. This function is also + * responsible for checking the authentication tag size for + * validity. + * @setkey: see struct ablkcipher_alg + * @encrypt: see struct ablkcipher_alg + * @decrypt: see struct ablkcipher_alg + * @givencrypt: see struct ablkcipher_alg + * @givdecrypt: see struct ablkcipher_alg + * @geniv: see struct ablkcipher_alg + * @ivsize: see struct ablkcipher_alg + * + * All fields except @givencrypt , @givdecrypt , @geniv and @ivsize are + * mandatory and must be filled. + */ struct aead_alg { int (*setkey)(struct crypto_aead *tfm, const u8 *key, unsigned int keylen); @@ -228,6 +328,18 @@ struct aead_alg { unsigned int maxauthsize; }; +/** + * struct blkcipher_alg - synchronous block cipher definition + * @min_keysize: see struct ablkcipher_alg + * @max_keysize: see struct ablkcipher_alg + * @setkey: see struct ablkcipher_alg + * @encrypt: see struct ablkcipher_alg + * @decrypt: see struct ablkcipher_alg + * @geniv: see struct ablkcipher_alg + * @ivsize: see struct ablkcipher_alg + * + * All fields except @geniv and @ivsize are mandatory and must be filled. + */ struct blkcipher_alg { int (*setkey)(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen); @@ -245,6 +357,53 @@ struct blkcipher_alg { unsigned int ivsize; }; +/** + * struct cipher_alg - single-block symmetric ciphers definition + * @cia_min_keysize: 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 "_MIN_KEY_SIZE" + * include/crypto/ + * @cia_max_keysize: 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 "_MAX_KEY_SIZE" + * include/crypto/ + * @cia_setkey: 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. + * @cia_encrypt: Encrypt a single block. This function is used to encrypt a + * single block of data, which must be @cra_blocksize big. This + * always operates on a full @cra_blocksize and it is not possible + * to encrypt a block of smaller size. The supplied buffers must + * therefore also be at least of @cra_blocksize size. Both the + * input and output buffers are always aligned to @cra_alignmask. + * In case either of the input or output buffer supplied by user + * of the crypto API is not aligned to @cra_alignmask, the crypto + * API will re-align the buffers. The re-alignment means that a + * new buffer will be allocated, the data will be copied into the + * new buffer, then the processing will happen on the new buffer, + * then the data will be copied back into the original buffer and + * finally the new buffer will be freed. In case a software + * fallback was put in place in the @cra_init call, this function + * might need to use the fallback if the algorithm doesn't 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. + * @cia_decrypt: Decrypt a single block. This is a reverse counterpart to + * @cia_encrypt, and the conditions are exactly the same. + * + * All fields are mandatory and must be filled. + */ struct cipher_alg { unsigned int cia_min_keysize; unsigned int cia_max_keysize; @@ -261,6 +420,25 @@ struct compress_alg { unsigned int slen, u8 *dst, unsigned int *dlen); }; +/** + * struct rng_alg - random number generator definition + * @rng_make_random: The function defined by this variable obtains a random + * number. The random number generator transform must generate + * the random number out of the context provided with this + * call. + * @rng_reset: Reset of the random number generator by clearing the entire state. + * With the invocation of this function call, the random number + * generator shall completely reinitialize its state. If the random + * number generator requires a seed for setting up a new state, + * the seed must be provided by the consumer while invoking this + * function. The required size of the seed is defined with + * @seedsize . + * @seedsize: The seed size required for a random number generator + * initialization defined with this variable. Some random number + * generators like the SP800-90A DRBG does not require a seed as the + * seeding is implemented internally without the need of support by + * the consumer. In this case, the seed size is set to zero. + */ struct rng_alg { int (*rng_make_random)(struct crypto_rng *tfm, u8 *rdata, unsigned int dlen); @@ -277,6 +455,81 @@ struct rng_alg { #define cra_compress cra_u.compress #define cra_rng cra_u.rng +/** + * struct crypto_alg - definition of a cryptograpic cipher algorithm + * @cra_flags: Flags describing this transformation. See include/linux/crypto.h + * CRYPTO_ALG_* flags for the flags which go in here. Those are + * used for fine-tuning the description of the transformation + * algorithm. + * @cra_blocksize: Minimum block size of this transformation. The size in bytes + * of the smallest possible unit which can be transformed with + * this algorithm. The users must respect this value. + * In case of HASH transformation, it is possible for a smaller + * block than @cra_blocksize to be passed to the crypto API for + * transformation, in case of any other transformation type, an + * error will be returned upon any attempt to transform smaller + * than @cra_blocksize chunks. + * @cra_ctxsize: Size of the operational context of the transformation. This + * value informs the kernel crypto API about the memory size + * needed to be allocated for the transformation context. + * @cra_alignmask: Alignment mask for the input and output data buffer. The data + * buffer containing the input data for the algorithm must be + * aligned to this alignment mask. The data buffer for the + * output data must be aligned to this alignment mask. Note that + * the Crypto API will do the re-alignment in software, but + * only under special conditions and there is a performance hit. + * The re-alignment happens at these occasions for different + * @cra_u types: cipher -- For both input data and output data + * buffer; ahash -- For output hash destination buf; shash -- + * For output hash destination buf. + * This is needed on hardware which is flawed by design and + * cannot pick data from arbitrary addresses. + * @cra_priority: Priority of this transformation implementation. In case + * multiple transformations with same @cra_name are available to + * the Crypto API, the kernel will use the one with highest + * @cra_priority. + * @cra_name: Generic name (usable by multiple implementations) of the + * transformation algorithm. This is the name of the transformation + * itself. This field is used by the kernel when looking up the + * providers of particular transformation. + * @cra_driver_name: Unique name of the transformation provider. This is the + * name of the provider of the transformation. This can be any + * arbitrary value, but in the usual case, this contains the + * name of the chip or provider and the name of the + * transformation algorithm. + * @cra_type: Type of the cryptographic transformation. This is a pointer to + * struct crypto_type, which implements callbacks common for all + * trasnformation types. There are multiple options: + * &crypto_blkcipher_type, &crypto_ablkcipher_type, + * &crypto_ahash_type, &crypto_aead_type, &crypto_rng_type. + * This field might be empty. In that case, there are no common + * callbacks. This is the case for: cipher, compress, shash. + * @cra_u: Callbacks implementing the transformation. This is a union of + * multiple structures. Depending on the type of transformation selected + * by @cra_type and @cra_flags above, the associated structure must be + * filled with callbacks. This field might be empty. This is the case + * for ahash, shash. + * @cra_init: Initialize the cryptographic transformation object. This function + * is used to initialize the cryptographic transformation object. + * This function is called only once at the instantiation time, right + * after the transformation context was allocated. In case the + * cryptographic hardware has some special requirements which need to + * be handled by software, this function shall check for the precise + * requirement of the transformation and put any software fallbacks + * in place. + * @cra_exit: Deinitialize the cryptographic transformation object. This is a + * counterpart to @cra_init, used to remove various changes set in + * @cra_init. + * @cra_module: Owner of this transformation implementation. Set to THIS_MODULE + * @cra_list: internally used + * @cra_users: internally used + * @cra_refcnt: internally used + * @cra_destroy: internally used + * + * The struct crypto_alg describes a generic Crypto API algorithm and is common + * for all of the transformations. Any variable not documented here shall not + * be used by a cipher implementation as it is internal to the Crypto API. + */ struct crypto_alg { struct list_head cra_list; struct list_head cra_users; @@ -581,6 +834,50 @@ static inline u32 crypto_skcipher_mask(u32 mask) return mask; } +/** + * DOC: Asynchronous Block Cipher API + * + * Asynchronous block cipher API is used with the ciphers of type + * CRYPTO_ALG_TYPE_ABLKCIPHER (listed as type "ablkcipher" in /proc/crypto). + * + * Asynchronous cipher operations imply that the function invocation for a + * cipher request returns immediately before the completion of the operation. + * The cipher request is scheduled as a separate kernel thread and therefore + * load-balanced on the different CPUs via the process scheduler. To allow + * the kernel crypto API to inform the caller about the completion of a cipher + * request, the caller must provide a callback function. That function is + * invoked with the cipher handle when the request completes. + * + * To support the asynchronous operation, additional information than just the + * cipher handle must be supplied to the kernel crypto API. That additional + * information is given by filling in the ablkcipher_request data structure. + * + * For the asynchronous block cipher API, the state is maintained with the tfm + * cipher handle. A single tfm can be used across multiple calls and in + * parallel. For asynchronous block cipher calls, context data supplied and + * only used by the caller can be referenced the request data structure in + * addition to the IV used for the cipher request. The maintenance of such + * state information would be important for a crypto driver implementer to + * have, because when calling the callback function upon completion of the + * cipher operation, that callback function may need some information about + * which operation just finished if it invoked multiple in parallel. This + * state information is unused by the kernel crypto API. + */ + +/** + * crypto_alloc_ablkcipher() - allocate asynchronous block cipher handle + * @alg_name: is the cra_name / name or cra_driver_name / driver name of the + * ablkcipher cipher + * @type: specifies the type of the cipher + * @mask: specifies the mask for the cipher + * + * Allocate a cipher handle for an ablkcipher. The returned struct + * crypto_ablkcipher is the cipher handle that is required for any subsequent + * API invocation for that ablkcipher. + * + * Return: allocated cipher handle in case of success; IS_ERR() is true in case + * of an error, PTR_ERR() returns the error code. + */ struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name, u32 type, u32 mask); @@ -590,11 +887,25 @@ static inline struct crypto_tfm *crypto_ablkcipher_tfm( return &tfm->base; } +/** + * crypto_free_ablkcipher() - zeroize and free cipher handle + * @tfm: cipher handle to be freed + */ static inline void crypto_free_ablkcipher(struct crypto_ablkcipher *tfm) { crypto_free_tfm(crypto_ablkcipher_tfm(tfm)); } +/** + * crypto_has_ablkcipher() - Search for the availability of an ablkcipher. + * @alg_name: is the cra_name / name or cra_driver_name / driver name of the + * ablkcipher + * @type: specifies the type of the cipher + * @mask: specifies the mask for the cipher + * + * Return: true when the ablkcipher is known to the kernel crypto API; false + * otherwise + */ static inline int crypto_has_ablkcipher(const char *alg_name, u32 type, u32 mask) { @@ -608,12 +919,31 @@ static inline struct ablkcipher_tfm *crypto_ablkcipher_crt( return &crypto_ablkcipher_tfm(tfm)->crt_ablkcipher; } +/** + * crypto_ablkcipher_ivsize() - obtain IV size + * @tfm: cipher handle + * + * The size of the IV for the ablkcipher referenced by the cipher handle is + * returned. This IV size may be zero if the cipher does not need an IV. + * + * Return: IV size in bytes + */ static inline unsigned int crypto_ablkcipher_ivsize( struct crypto_ablkcipher *tfm) { return crypto_ablkcipher_crt(tfm)->ivsize; } +/** + * crypto_ablkcipher_blocksize() - obtain block size of cipher + * @tfm: cipher handle + * + * The block size for the ablkcipher referenced with the cipher handle is + * returned. The caller may use that information to allocate appropriate + * memory for the data returned by the encryption or decryption operation + * + * Return: block size of cipher + */ static inline unsigned int crypto_ablkcipher_blocksize( struct crypto_ablkcipher *tfm) { @@ -643,6 +973,22 @@ static inline void crypto_ablkcipher_clear_flags(struct crypto_ablkcipher *tfm, crypto_tfm_clear_flags(crypto_ablkcipher_tfm(tfm), flags); } +/** + * crypto_ablkcipher_setkey() - set key for cipher + * @tfm: cipher handle + * @key: buffer holding the key + * @keylen: length of the key in bytes + * + * The caller provided key is set for the ablkcipher referenced by the cipher + * handle. + * + * Note, the key length determines the cipher type. Many block ciphers implement + * different cipher modes depending on the key size, such as AES-128 vs AES-192 + * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128 + * is performed. + * + * Return: 0 if the setting of the key was successful; < 0 if an error occurred + */ static inline int crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm, const u8 *key, unsigned int keylen) { @@ -651,12 +997,32 @@ static inline int crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm, return crt->setkey(crt->base, key, keylen); } +/** + * crypto_ablkcipher_reqtfm() - obtain cipher handle from request + * @req: ablkcipher_request out of which the cipher handle is to be obtained + * + * Return the crypto_ablkcipher handle when furnishing an ablkcipher_request + * data structure. + * + * Return: crypto_ablkcipher handle + */ static inline struct crypto_ablkcipher *crypto_ablkcipher_reqtfm( struct ablkcipher_request *req) { return __crypto_ablkcipher_cast(req->base.tfm); } +/** + * crypto_ablkcipher_encrypt() - encrypt plaintext + * @req: reference to the ablkcipher_request handle that holds all information + * needed to perform the cipher operation + * + * Encrypt plaintext data using the ablkcipher_request handle. That data + * structure and how it is filled with data is discussed with the + * ablkcipher_request_* functions. + * + * Return: 0 if the cipher operation was successful; < 0 if an error occurred + */ static inline int crypto_ablkcipher_encrypt(struct ablkcipher_request *req) { struct ablkcipher_tfm *crt = @@ -664,6 +1030,17 @@ static inline int crypto_ablkcipher_encrypt(struct ablkcipher_request *req) return crt->encrypt(req); } +/** + * crypto_ablkcipher_decrypt() - decrypt ciphertext + * @req: reference to the ablkcipher_request handle that holds all information + * needed to perform the cipher operation + * + * Decrypt ciphertext data using the ablkcipher_request handle. That data + * structure and how it is filled with data is discussed with the + * ablkcipher_request_* functions. + * + * Return: 0 if the cipher operation was successful; < 0 if an error occurred + */ static inline int crypto_ablkcipher_decrypt(struct ablkcipher_request *req) { struct ablkcipher_tfm *crt = @@ -671,12 +1048,37 @@ static inline int crypto_ablkcipher_decrypt(struct ablkcipher_request *req) return crt->decrypt(req); } +/** + * DOC: Asynchronous Cipher Request Handle + * + * The ablkcipher_request data structure contains all pointers to data + * required for the asynchronous cipher operation. This includes the cipher + * handle (which can be used by multiple ablkcipher_request instances), pointer + * to plaintext and ciphertext, asynchronous callback function, etc. It acts + * as a handle to the ablkcipher_request_* API calls in a similar way as + * ablkcipher handle to the crypto_ablkcipher_* API calls. + */ + +/** + * crypto_ablkcipher_reqsize() - obtain size of the request data structure + * @tfm: cipher handle + * + * Return: number of bytes + */ static inline unsigned int crypto_ablkcipher_reqsize( struct crypto_ablkcipher *tfm) { return crypto_ablkcipher_crt(tfm)->reqsize; } +/** + * ablkcipher_request_set_tfm() - update cipher handle reference in request + * @req: request handle to be modified + * @tfm: cipher handle that shall be added to the request handle + * + * Allow the caller to replace the existing ablkcipher handle in the request + * data structure with a different one. + */ static inline void ablkcipher_request_set_tfm( struct ablkcipher_request *req, struct crypto_ablkcipher *tfm) { @@ -689,6 +1091,18 @@ static inline struct ablkcipher_request *ablkcipher_request_cast( return container_of(req, struct ablkcipher_request, base); } +/** + * ablkcipher_request_alloc() - allocate request data structure + * @tfm: cipher handle to be registered with the request + * @gfp: memory allocation flag that is handed to kmalloc by the API call. + * + * Allocate the request data structure that must be used with the ablkcipher + * encrypt and decrypt API calls. During the allocation, the provided ablkcipher + * handle is registered in the request data structure. + * + * Return: allocated request handle in case of success; IS_ERR() is true in case + * of an error, PTR_ERR() returns the error code. + */ static inline struct ablkcipher_request *ablkcipher_request_alloc( struct crypto_ablkcipher *tfm, gfp_t gfp) { @@ -703,11 +1117,40 @@ static inline struct ablkcipher_request *ablkcipher_request_alloc( return req; } +/** + * ablkcipher_request_free() - zeroize and free request data structure + * @req: request data structure cipher handle to be freed + */ static inline void ablkcipher_request_free(struct ablkcipher_request *req) { kzfree(req); } +/** + * ablkcipher_request_set_callback() - set asynchronous callback function + * @req: request handle + * @flags: specify zero or an ORing of the flags + * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and + * increase the wait queue beyond the initial maximum size; + * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep + * @compl: callback function pointer to be registered with the request handle + * @data: The data pointer refers to memory that is not used by the kernel + * crypto API, but provided to the callback function for it to use. Here, + * the caller can provide a reference to memory the callback function can + * operate on. As the callback function is invoked asynchronously to the + * related functionality, it may need to access data structures of the + * related functionality which can be referenced using this pointer. The + * callback function can access the memory via the "data" field in the + * crypto_async_request data structure provided to the callback function. + * + * This function allows setting the callback function that is triggered once the + * cipher operation completes. + * + * The callback function is registered with the ablkcipher_request handle and + * must comply with the following template: + * + * void callback_function(struct crypto_async_request *req, int error) + */ static inline void ablkcipher_request_set_callback( struct ablkcipher_request *req, u32 flags, crypto_completion_t compl, void *data) @@ -717,6 +1160,22 @@ static inline void ablkcipher_request_set_callback( req->base.flags = flags; } +/** + * ablkcipher_request_set_crypt() - set data buffers + * @req: request handle + * @src: source scatter / gather list + * @dst: destination scatter / gather list + * @nbytes: number of bytes to process from @src + * @iv: IV for the cipher operation which must comply with the IV size defined + * by crypto_ablkcipher_ivsize + * + * This function allows setting of the source data and destination data + * scatter / gather lists. + * + * 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. + */ static inline void ablkcipher_request_set_crypt( struct ablkcipher_request *req, struct scatterlist *src, struct scatterlist *dst, @@ -728,11 +1187,55 @@ static inline void ablkcipher_request_set_crypt( req->info = iv; } +/** + * DOC: Authenticated Encryption With Associated Data (AEAD) Cipher API + * + * The AEAD cipher API is used with the ciphers of type CRYPTO_ALG_TYPE_AEAD + * (listed as type "aead" in /proc/crypto) + * + * The most prominent examples for this type of encryption is GCM and CCM. + * However, the kernel supports other types of AEAD ciphers which are defined + * with the following cipher string: + * + * authenc(keyed message digest, block cipher) + * + * For example: authenc(hmac(sha256), cbc(aes)) + * + * The example code provided for the asynchronous block cipher operation + * applies here as well. Naturally all *ablkcipher* symbols must be exchanged + * the *aead* pendants discussed in the following. In addtion, for the AEAD + * operation, the aead_request_set_assoc function must be used to set the + * pointer to the associated data memory location before performing the + * encryption or decryption operation. In case of an encryption, the associated + * data memory is filled during the encryption operation. For decryption, the + * associated data memory must contain data that is used to verify the integrity + * of the decrypted data. Another deviation from the asynchronous block cipher + * operation is that the caller should explicitly check for -EBADMSG of the + * crypto_aead_decrypt. That error indicates an authentication error, i.e. + * a breach in the integrity of the message. In essence, that -EBADMSG error + * code is the key bonus an AEAD cipher has over "standard" block chaining + * modes. + */ + static inline struct crypto_aead *__crypto_aead_cast(struct crypto_tfm *tfm) { return (struct crypto_aead *)tfm; } +/** + * crypto_alloc_aead() - allocate AEAD cipher handle + * @alg_name: is the cra_name / name or cra_driver_name / driver name of the + * AEAD cipher + * @type: specifies the type of the cipher + * @mask: specifies the mask for the cipher + * + * Allocate a cipher handle for an AEAD. The returned struct + * crypto_aead is the cipher handle that is required for any subsequent + * API invocation for that AEAD. + * + * Return: allocated cipher handle in case of success; IS_ERR() is true in case + * of an error, PTR_ERR() returns the error code. + */ struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask); static inline struct crypto_tfm *crypto_aead_tfm(struct crypto_aead *tfm) @@ -740,6 +1243,10 @@ static inline struct crypto_tfm *crypto_aead_tfm(struct crypto_aead *tfm) return &tfm->base; } +/** + * crypto_free_aead() - zeroize and free aead handle + * @tfm: cipher handle to be freed + */ static inline void crypto_free_aead(struct crypto_aead *tfm) { crypto_free_tfm(crypto_aead_tfm(tfm)); @@ -750,16 +1257,47 @@ static inline struct aead_tfm *crypto_aead_crt(struct crypto_aead *tfm) return &crypto_aead_tfm(tfm)->crt_aead; } +/** + * crypto_aead_ivsize() - obtain IV size + * @tfm: cipher handle + * + * The size of the IV for the aead referenced by the cipher handle is + * returned. This IV size may be zero if the cipher does not need an IV. + * + * Return: IV size in bytes + */ static inline unsigned int crypto_aead_ivsize(struct crypto_aead *tfm) { return crypto_aead_crt(tfm)->ivsize; } +/** + * crypto_aead_authsize() - obtain maximum authentication data size + * @tfm: cipher handle + * + * The maximum size of the authentication data for the AEAD cipher referenced + * by the AEAD cipher handle is returned. The authentication data size may be + * zero if the cipher implements a hard-coded maximum. + * + * The authentication data may also be known as "tag value". + * + * Return: authentication data size / tag size in bytes + */ static inline unsigned int crypto_aead_authsize(struct crypto_aead *tfm) { return crypto_aead_crt(tfm)->authsize; } +/** + * crypto_aead_blocksize() - obtain block size of cipher + * @tfm: cipher handle + * + * The block size for the AEAD referenced with the cipher handle is returned. + * The caller may use that information to allocate appropriate memory for the + * data returned by the encryption or decryption operation + * + * Return: block size of cipher + */ static inline unsigned int crypto_aead_blocksize(struct crypto_aead *tfm) { return crypto_tfm_alg_blocksize(crypto_aead_tfm(tfm)); @@ -785,6 +1323,22 @@ static inline void crypto_aead_clear_flags(struct crypto_aead *tfm, u32 flags) crypto_tfm_clear_flags(crypto_aead_tfm(tfm), flags); } +/** + * crypto_aead_setkey() - set key for cipher + * @tfm: cipher handle + * @key: buffer holding the key + * @keylen: length of the key in bytes + * + * The caller provided key is set for the AEAD referenced by the cipher + * handle. + * + * Note, the key length determines the cipher type. Many block ciphers implement + * different cipher modes depending on the key size, such as AES-128 vs AES-192 + * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128 + * is performed. + * + * Return: 0 if the setting of the key was successful; < 0 if an error occurred + */ static inline int crypto_aead_setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen) { @@ -793,6 +1347,16 @@ static inline int crypto_aead_setkey(struct crypto_aead *tfm, const u8 *key, return crt->setkey(crt->base, key, keylen); } +/** + * crypto_aead_setauthsize() - set authentication data size + * @tfm: cipher handle + * @authsize: size of the authentication data / tag in bytes + * + * Set the authentication data size / tag size. AEAD requires an authentication + * tag (or MAC) in addition to the associated data. + * + * Return: 0 if the setting of the key was successful; < 0 if an error occurred + */ int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize); static inline struct crypto_aead *crypto_aead_reqtfm(struct aead_request *req) @@ -800,27 +1364,105 @@ static inline struct crypto_aead *crypto_aead_reqtfm(struct aead_request *req) return __crypto_aead_cast(req->base.tfm); } +/** + * crypto_aead_encrypt() - encrypt plaintext + * @req: reference to the aead_request handle that holds all information + * needed to perform the cipher operation + * + * Encrypt plaintext data using the aead_request handle. That data structure + * and how it is filled with data is discussed with the aead_request_* + * functions. + * + * IMPORTANT NOTE The encryption operation creates the authentication data / + * tag. That data is concatenated with the created ciphertext. + * The ciphertext memory size is therefore the given number of + * block cipher blocks + the size defined by the + * crypto_aead_setauthsize invocation. The caller must ensure + * that sufficient memory is available for the ciphertext and + * the authentication tag. + * + * Return: 0 if the cipher operation was successful; < 0 if an error occurred + */ static inline int crypto_aead_encrypt(struct aead_request *req) { return crypto_aead_crt(crypto_aead_reqtfm(req))->encrypt(req); } +/** + * crypto_aead_decrypt() - decrypt ciphertext + * @req: reference to the ablkcipher_request handle that holds all information + * needed to perform the cipher operation + * + * Decrypt ciphertext data using the aead_request handle. That data structure + * and how it is filled with data is discussed with the aead_request_* + * functions. + * + * IMPORTANT NOTE The caller must concatenate the ciphertext followed by the + * authentication data / tag. That authentication data / tag + * must have the size defined by the crypto_aead_setauthsize + * invocation. + * + * + * Return: 0 if the cipher operation was successful; -EBADMSG: The AEAD + * cipher operation performs the authentication of the data during the + * decryption operation. Therefore, the function returns this error if + * the authentication of the ciphertext was unsuccessful (i.e. the + * integrity of the ciphertext or the associated data was violated); + * < 0 if an error occurred. + */ static inline int crypto_aead_decrypt(struct aead_request *req) { return crypto_aead_crt(crypto_aead_reqtfm(req))->decrypt(req); } +/** + * DOC: Asynchronous AEAD Request Handle + * + * The aead_request data structure contains all pointers to data required for + * the AEAD cipher operation. This includes the cipher handle (which can be + * used by multiple aead_request instances), pointer to plaintext and + * ciphertext, asynchronous callback function, etc. It acts as a handle to the + * aead_request_* API calls in a similar way as AEAD handle to the + * crypto_aead_* API calls. + */ + +/** + * crypto_aead_reqsize() - obtain size of the request data structure + * @tfm: cipher handle + * + * Return: number of bytes + */ static inline unsigned int crypto_aead_reqsize(struct crypto_aead *tfm) { return crypto_aead_crt(tfm)->reqsize; } +/** + * aead_request_set_tfm() - update cipher handle reference in request + * @req: request handle to be modified + * @tfm: cipher handle that shall be added to the request handle + * + * Allow the caller to replace the existing aead handle in the request + * data structure with a different one. + */ static inline void aead_request_set_tfm(struct aead_request *req, struct crypto_aead *tfm) { req->base.tfm = crypto_aead_tfm(crypto_aead_crt(tfm)->base); } +/** + * aead_request_alloc() - allocate request data structure + * @tfm: cipher handle to be registered with the request + * @gfp: memory allocation flag that is handed to kmalloc by the API call. + * + * Allocate the request data structure that must be used with the AEAD + * encrypt and decrypt API calls. During the allocation, the provided aead + * handle is registered in the request data structure. + * + * Return: allocated request handle in case of success; IS_ERR() is true in case + * of an error, PTR_ERR() returns the error code. + */ static inline struct aead_request *aead_request_alloc(struct crypto_aead *tfm, gfp_t gfp) { @@ -834,11 +1476,40 @@ static inline struct aead_request *aead_request_alloc(struct crypto_aead *tfm, return req; } +/** + * aead_request_free() - zeroize and free request data structure + * @req: request data structure cipher handle to be freed + */ static inline void aead_request_free(struct aead_request *req) { kzfree(req); } +/** + * aead_request_set_callback() - set asynchronous callback function + * @req: request handle + * @flags: specify zero or an ORing of the flags + * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and + * increase the wait queue beyond the initial maximum size; + * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep + * @compl: callback function pointer to be registered with the request handle + * @data: The data pointer refers to memory that is not used by the kernel + * crypto API, but provided to the callback function for it to use. Here, + * the caller can provide a reference to memory the callback function can + * operate on. As the callback function is invoked asynchronously to the + * related functionality, it may need to access data structures of the + * related functionality which can be referenced using this pointer. The + * callback function can access the memory via the "data" field in the + * crypto_async_request data structure provided to the callback function. + * + * Setting the callback function that is triggered once the cipher operation + * completes + * + * The callback function is registered with the aead_request handle and + * must comply with the following template: + * + * void callback_function(struct crypto_async_request *req, int error) + */ static inline void aead_request_set_callback(struct aead_request *req, u32 flags, crypto_completion_t compl, @@ -849,6 +1520,36 @@ static inline void aead_request_set_callback(struct aead_request *req, req->base.flags = flags; } +/** + * aead_request_set_crypt - set data buffers + * @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() + * + * Setting the source data and destination data scatter / gather lists. + * + * 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. + * + * 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); + */ static inline void aead_request_set_crypt(struct aead_request *req, struct scatterlist *src, struct scatterlist *dst, @@ -860,6 +1561,15 @@ static inline void aead_request_set_crypt(struct aead_request *req, req->iv = iv; } +/** + * aead_request_set_assoc() - set the associated data scatter / gather list + * @req: request handle + * @assoc: associated data scatter / gather list + * @assoclen: number of bytes to process from @assoc + * + * For encryption, the memory is filled with the associated data. For + * decryption, the memory must point to the associated data. + */ static inline void aead_request_set_assoc(struct aead_request *req, struct scatterlist *assoc, unsigned int assoclen) @@ -868,6 +1578,36 @@ static inline void aead_request_set_assoc(struct aead_request *req, req->assoclen = assoclen; } +/** + * DOC: Synchronous Block Cipher API + * + * The synchronous block cipher API is used with the ciphers of type + * CRYPTO_ALG_TYPE_BLKCIPHER (listed as type "blkcipher" in /proc/crypto) + * + * Synchronous calls, have a context in the tfm. But since a single tfm can be + * used in multiple calls and in parallel, this info should not be changeable + * (unless a lock is used). This applies, for example, to the symmetric key. + * However, the IV is changeable, so there is an iv field in blkcipher_tfm + * structure for synchronous blkcipher api. So, its the only state info that can + * be kept for synchronous calls without using a big lock across a tfm. + * + * The block cipher API allows the use of a complete cipher, i.e. a cipher + * consisting of a template (a block chaining mode) and a single block cipher + * primitive (e.g. AES). + * + * The plaintext data buffer and the ciphertext data buffer are pointed to + * by using scatter/gather lists. The cipher operation is performed + * on all segments of the provided scatter/gather lists. + * + * The kernel crypto API supports a cipher operation "in-place" which means that + * the caller may provide the same scatter/gather list for the plaintext and + * cipher text. After the completion of the cipher operation, the plaintext + * data is replaced with the ciphertext data in case of an encryption and vice + * versa for a decryption. The caller must ensure that the scatter/gather lists + * for the output data point to sufficiently large buffers, i.e. multiples of + * the block size of the cipher. + */ + static inline struct crypto_blkcipher *__crypto_blkcipher_cast( struct crypto_tfm *tfm) { @@ -881,6 +1621,20 @@ static inline struct crypto_blkcipher *crypto_blkcipher_cast( return __crypto_blkcipher_cast(tfm); } +/** + * crypto_alloc_blkcipher() - allocate synchronous block cipher handle + * @alg_name: is the cra_name / name or cra_driver_name / driver name of the + * blkcipher cipher + * @type: specifies the type of the cipher + * @mask: specifies the mask for the cipher + * + * Allocate a cipher handle for a block cipher. The returned struct + * crypto_blkcipher is the cipher handle that is required for any subsequent + * API invocation for that block cipher. + * + * Return: allocated cipher handle in case of success; IS_ERR() is true in case + * of an error, PTR_ERR() returns the error code. + */ static inline struct crypto_blkcipher *crypto_alloc_blkcipher( const char *alg_name, u32 type, u32 mask) { @@ -897,11 +1651,25 @@ static inline struct crypto_tfm *crypto_blkcipher_tfm( return &tfm->base; } +/** + * crypto_free_blkcipher() - zeroize and free the block cipher handle + * @tfm: cipher handle to be freed + */ static inline void crypto_free_blkcipher(struct crypto_blkcipher *tfm) { crypto_free_tfm(crypto_blkcipher_tfm(tfm)); } +/** + * crypto_has_blkcipher() - Search for the availability of a block cipher + * @alg_name: is the cra_name / name or cra_driver_name / driver name of the + * block cipher + * @type: specifies the type of the cipher + * @mask: specifies the mask for the cipher + * + * Return: true when the block cipher is known to the kernel crypto API; false + * otherwise + */ static inline int crypto_has_blkcipher(const char *alg_name, u32 type, u32 mask) { type &= ~CRYPTO_ALG_TYPE_MASK; @@ -911,6 +1679,12 @@ static inline int crypto_has_blkcipher(const char *alg_name, u32 type, u32 mask) return crypto_has_alg(alg_name, type, mask); } +/** + * crypto_blkcipher_name() - return the name / cra_name from the cipher handle + * @tfm: cipher handle + * + * Return: The character string holding the name of the cipher + */ static inline const char *crypto_blkcipher_name(struct crypto_blkcipher *tfm) { return crypto_tfm_alg_name(crypto_blkcipher_tfm(tfm)); @@ -928,11 +1702,30 @@ static inline struct blkcipher_alg *crypto_blkcipher_alg( return &crypto_blkcipher_tfm(tfm)->__crt_alg->cra_blkcipher; } +/** + * crypto_blkcipher_ivsize() - obtain IV size + * @tfm: cipher handle + * + * The size of the IV for the block cipher referenced by the cipher handle is + * returned. This IV size may be zero if the cipher does not need an IV. + * + * Return: IV size in bytes + */ static inline unsigned int crypto_blkcipher_ivsize(struct crypto_blkcipher *tfm) { return crypto_blkcipher_alg(tfm)->ivsize; } +/** + * crypto_blkcipher_blocksize() - obtain block size of cipher + * @tfm: cipher handle + * + * The block size for the block cipher referenced with the cipher handle is + * returned. The caller may use that information to allocate appropriate + * memory for the data returned by the encryption or decryption operation. + * + * Return: block size of cipher + */ static inline unsigned int crypto_blkcipher_blocksize( struct crypto_blkcipher *tfm) { @@ -962,6 +1755,22 @@ static inline void crypto_blkcipher_clear_flags(struct crypto_blkcipher *tfm, crypto_tfm_clear_flags(crypto_blkcipher_tfm(tfm), flags); } +/** + * crypto_blkcipher_setkey() - set key for cipher + * @tfm: cipher handle + * @key: buffer holding the key + * @keylen: length of the key in bytes + * + * The caller provided key is set for the block cipher referenced by the cipher + * handle. + * + * Note, the key length determines the cipher type. Many block ciphers implement + * different cipher modes depending on the key size, such as AES-128 vs AES-192 + * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128 + * is performed. + * + * Return: 0 if the setting of the key was successful; < 0 if an error occurred + */ static inline int crypto_blkcipher_setkey(struct crypto_blkcipher *tfm, const u8 *key, unsigned int keylen) { @@ -969,6 +1778,24 @@ static inline int crypto_blkcipher_setkey(struct crypto_blkcipher *tfm, key, keylen); } +/** + * crypto_blkcipher_encrypt() - encrypt plaintext + * @desc: reference to the block cipher handle with meta data + * @dst: scatter/gather list that is filled by the cipher operation with the + * ciphertext + * @src: scatter/gather list that holds the plaintext + * @nbytes: number of bytes of the plaintext to encrypt. + * + * Encrypt plaintext data using the IV set by the caller with a preceding + * call of crypto_blkcipher_set_iv. + * + * The blkcipher_desc data structure must be filled by the caller and can + * reside on the stack. The caller must fill desc as follows: desc.tfm is filled + * with the block cipher handle; desc.flags is filled with either + * CRYPTO_TFM_REQ_MAY_SLEEP or 0. + * + * Return: 0 if the cipher operation was successful; < 0 if an error occurred + */ static inline int crypto_blkcipher_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, @@ -978,6 +1805,25 @@ static inline int crypto_blkcipher_encrypt(struct blkcipher_desc *desc, return crypto_blkcipher_crt(desc->tfm)->encrypt(desc, dst, src, nbytes); } +/** + * crypto_blkcipher_encrypt_iv() - encrypt plaintext with dedicated IV + * @desc: reference to the block cipher handle with meta data + * @dst: scatter/gather list that is filled by the cipher operation with the + * ciphertext + * @src: scatter/gather list that holds the plaintext + * @nbytes: number of bytes of the plaintext to encrypt. + * + * Encrypt plaintext data with the use of an IV that is solely used for this + * cipher operation. Any previously set IV is not used. + * + * The blkcipher_desc data structure must be filled by the caller and can + * reside on the stack. The caller must fill desc as follows: desc.tfm is filled + * with the block cipher handle; desc.info is filled with the IV to be used for + * the current operation; desc.flags is filled with either + * CRYPTO_TFM_REQ_MAY_SLEEP or 0. + * + * Return: 0 if the cipher operation was successful; < 0 if an error occurred + */ static inline int crypto_blkcipher_encrypt_iv(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, @@ -986,6 +1832,23 @@ static inline int crypto_blkcipher_encrypt_iv(struct blkcipher_desc *desc, return crypto_blkcipher_crt(desc->tfm)->encrypt(desc, dst, src, nbytes); } +/** + * crypto_blkcipher_decrypt() - decrypt ciphertext + * @desc: reference to the block cipher handle with meta data + * @dst: scatter/gather list that is filled by the cipher operation with the + * plaintext + * @src: scatter/gather list that holds the ciphertext + * @nbytes: number of bytes of the ciphertext to decrypt. + * + * Decrypt ciphertext data using the IV set by the caller with a preceding + * call of crypto_blkcipher_set_iv. + * + * The blkcipher_desc data structure must be filled by the caller as documented + * for the crypto_blkcipher_encrypt call above. + * + * Return: 0 if the cipher operation was successful; < 0 if an error occurred + * + */ static inline int crypto_blkcipher_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, @@ -995,6 +1858,22 @@ static inline int crypto_blkcipher_decrypt(struct blkcipher_desc *desc, return crypto_blkcipher_crt(desc->tfm)->decrypt(desc, dst, src, nbytes); } +/** + * crypto_blkcipher_decrypt_iv() - decrypt ciphertext with dedicated IV + * @desc: reference to the block cipher handle with meta data + * @dst: scatter/gather list that is filled by the cipher operation with the + * plaintext + * @src: scatter/gather list that holds the ciphertext + * @nbytes: number of bytes of the ciphertext to decrypt. + * + * Decrypt ciphertext data with the use of an IV that is solely used for this + * cipher operation. Any previously set IV is not used. + * + * The blkcipher_desc data structure must be filled by the caller as documented + * for the crypto_blkcipher_encrypt_iv call above. + * + * Return: 0 if the cipher operation was successful; < 0 if an error occurred + */ static inline int crypto_blkcipher_decrypt_iv(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, @@ -1003,18 +1882,54 @@ static inline int crypto_blkcipher_decrypt_iv(struct blkcipher_desc *desc, return crypto_blkcipher_crt(desc->tfm)->decrypt(desc, dst, src, nbytes); } +/** + * crypto_blkcipher_set_iv() - set IV for cipher + * @tfm: cipher handle + * @src: buffer holding the IV + * @len: length of the IV in bytes + * + * The caller provided IV is set for the block cipher referenced by the cipher + * handle. + */ static inline void crypto_blkcipher_set_iv(struct crypto_blkcipher *tfm, const u8 *src, unsigned int len) { memcpy(crypto_blkcipher_crt(tfm)->iv, src, len); } +/** + * crypto_blkcipher_get_iv() - obtain IV from cipher + * @tfm: cipher handle + * @dst: buffer filled with the IV + * @len: length of the buffer dst + * + * The caller can obtain the IV set for the block cipher referenced by the + * cipher handle and store it into the user-provided buffer. If the buffer + * has an insufficient space, the IV is truncated to fit the buffer. + */ static inline void crypto_blkcipher_get_iv(struct crypto_blkcipher *tfm, u8 *dst, unsigned int len) { memcpy(dst, crypto_blkcipher_crt(tfm)->iv, len); } +/** + * DOC: Single Block Cipher API + * + * The single block cipher API is used with the ciphers of type + * CRYPTO_ALG_TYPE_CIPHER (listed as type "cipher" in /proc/crypto). + * + * Using the single block cipher API calls, operations with the basic cipher + * primitive can be implemented. These cipher primitives exclude any block + * chaining operations including IV handling. + * + * The purpose of this single block cipher API is to support the implementation + * of templates or other concepts that only need to perform the cipher operation + * on one block at a time. Templates invoke the underlying cipher primitive + * block-wise and process either the input or the output data of these cipher + * operations. + */ + static inline struct crypto_cipher *__crypto_cipher_cast(struct crypto_tfm *tfm) { return (struct crypto_cipher *)tfm; @@ -1026,6 +1941,20 @@ static inline struct crypto_cipher *crypto_cipher_cast(struct crypto_tfm *tfm) return __crypto_cipher_cast(tfm); } +/** + * crypto_alloc_cipher() - allocate single block cipher handle + * @alg_name: is the cra_name / name or cra_driver_name / driver name of the + * single block cipher + * @type: specifies the type of the cipher + * @mask: specifies the mask for the cipher + * + * Allocate a cipher handle for a single block cipher. The returned struct + * crypto_cipher is the cipher handle that is required for any subsequent API + * invocation for that single block cipher. + * + * Return: allocated cipher handle in case of success; IS_ERR() is true in case + * of an error, PTR_ERR() returns the error code. + */ static inline struct crypto_cipher *crypto_alloc_cipher(const char *alg_name, u32 type, u32 mask) { @@ -1041,11 +1970,25 @@ static inline struct crypto_tfm *crypto_cipher_tfm(struct crypto_cipher *tfm) return &tfm->base; } +/** + * crypto_free_cipher() - zeroize and free the single block cipher handle + * @tfm: cipher handle to be freed + */ static inline void crypto_free_cipher(struct crypto_cipher *tfm) { crypto_free_tfm(crypto_cipher_tfm(tfm)); } +/** + * crypto_has_cipher() - Search for the availability of a single block cipher + * @alg_name: is the cra_name / name or cra_driver_name / driver name of the + * single block cipher + * @type: specifies the type of the cipher + * @mask: specifies the mask for the cipher + * + * Return: true when the single block cipher is known to the kernel crypto API; + * false otherwise + */ static inline int crypto_has_cipher(const char *alg_name, u32 type, u32 mask) { type &= ~CRYPTO_ALG_TYPE_MASK; @@ -1060,6 +2003,16 @@ static inline struct cipher_tfm *crypto_cipher_crt(struct crypto_cipher *tfm) return &crypto_cipher_tfm(tfm)->crt_cipher; } +/** + * crypto_cipher_blocksize() - obtain block size for cipher + * @tfm: cipher handle + * + * The block size for the single block cipher referenced with the cipher handle + * tfm is returned. The caller may use that information to allocate appropriate + * memory for the data returned by the encryption or decryption operation + * + * Return: block size of cipher + */ static inline unsigned int crypto_cipher_blocksize(struct crypto_cipher *tfm) { return crypto_tfm_alg_blocksize(crypto_cipher_tfm(tfm)); @@ -1087,6 +2040,22 @@ static inline void crypto_cipher_clear_flags(struct crypto_cipher *tfm, crypto_tfm_clear_flags(crypto_cipher_tfm(tfm), flags); } +/** + * crypto_cipher_setkey() - set key for cipher + * @tfm: cipher handle + * @key: buffer holding the key + * @keylen: length of the key in bytes + * + * The caller provided key is set for the single block cipher referenced by the + * cipher handle. + * + * Note, the key length determines the cipher type. Many block ciphers implement + * different cipher modes depending on the key size, such as AES-128 vs AES-192 + * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128 + * is performed. + * + * Return: 0 if the setting of the key was successful; < 0 if an error occurred + */ static inline int crypto_cipher_setkey(struct crypto_cipher *tfm, const u8 *key, unsigned int keylen) { @@ -1094,6 +2063,15 @@ static inline int crypto_cipher_setkey(struct crypto_cipher *tfm, key, keylen); } +/** + * crypto_cipher_encrypt_one() - encrypt one block of plaintext + * @tfm: cipher handle + * @dst: points to the buffer that will be filled with the ciphertext + * @src: buffer holding the plaintext to be encrypted + * + * Invoke the encryption operation of one block. The caller must ensure that + * the plaintext and ciphertext buffers are at least one block in size. + */ static inline void crypto_cipher_encrypt_one(struct crypto_cipher *tfm, u8 *dst, const u8 *src) { @@ -1101,6 +2079,15 @@ static inline void crypto_cipher_encrypt_one(struct crypto_cipher *tfm, dst, src); } +/** + * crypto_cipher_decrypt_one() - decrypt one block of ciphertext + * @tfm: cipher handle + * @dst: points to the buffer that will be filled with the plaintext + * @src: buffer holding the ciphertext to be decrypted + * + * Invoke the decryption operation of one block. The caller must ensure that + * the plaintext and ciphertext buffers are at least one block in size. + */ static inline void crypto_cipher_decrypt_one(struct crypto_cipher *tfm, u8 *dst, const u8 *src) { @@ -1108,6 +2095,13 @@ static inline void crypto_cipher_decrypt_one(struct crypto_cipher *tfm, dst, src); } +/** + * DOC: Synchronous Message Digest API + * + * The synchronous message digest API is used with the ciphers of type + * CRYPTO_ALG_TYPE_HASH (listed as type "hash" in /proc/crypto) + */ + static inline struct crypto_hash *__crypto_hash_cast(struct crypto_tfm *tfm) { return (struct crypto_hash *)tfm; @@ -1120,6 +2114,20 @@ static inline struct crypto_hash *crypto_hash_cast(struct crypto_tfm *tfm) return __crypto_hash_cast(tfm); } +/** + * crypto_alloc_hash() - allocate synchronous message digest handle + * @alg_name: is the cra_name / name or cra_driver_name / driver name of the + * message digest cipher + * @type: specifies the type of the cipher + * @mask: specifies the mask for the cipher + * + * Allocate a cipher handle for a message digest. The returned struct + * crypto_hash is the cipher handle that is required for any subsequent + * API invocation for that message digest. + * + * Return: allocated cipher handle in case of success; IS_ERR() is true in case + * of an error, PTR_ERR() returns the error code. + */ static inline struct crypto_hash *crypto_alloc_hash(const char *alg_name, u32 type, u32 mask) { @@ -1136,11 +2144,25 @@ static inline struct crypto_tfm *crypto_hash_tfm(struct crypto_hash *tfm) return &tfm->base; } +/** + * crypto_free_hash() - zeroize and free message digest handle + * @tfm: cipher handle to be freed + */ static inline void crypto_free_hash(struct crypto_hash *tfm) { crypto_free_tfm(crypto_hash_tfm(tfm)); } +/** + * crypto_has_hash() - Search for the availability of a message digest + * @alg_name: is the cra_name / name or cra_driver_name / driver name of the + * message digest cipher + * @type: specifies the type of the cipher + * @mask: specifies the mask for the cipher + * + * Return: true when the message digest cipher is known to the kernel crypto + * API; false otherwise + */ static inline int crypto_has_hash(const char *alg_name, u32 type, u32 mask) { type &= ~CRYPTO_ALG_TYPE_MASK; @@ -1156,6 +2178,15 @@ static inline struct hash_tfm *crypto_hash_crt(struct crypto_hash *tfm) return &crypto_hash_tfm(tfm)->crt_hash; } +/** + * crypto_hash_blocksize() - obtain block size for message digest + * @tfm: cipher handle + * + * The block size for the message digest cipher referenced with the cipher + * handle is returned. + * + * Return: block size of cipher + */ static inline unsigned int crypto_hash_blocksize(struct crypto_hash *tfm) { return crypto_tfm_alg_blocksize(crypto_hash_tfm(tfm)); @@ -1166,6 +2197,15 @@ static inline unsigned int crypto_hash_alignmask(struct crypto_hash *tfm) return crypto_tfm_alg_alignmask(crypto_hash_tfm(tfm)); } +/** + * crypto_hash_digestsize() - obtain message digest size + * @tfm: cipher handle + * + * The size for the message digest created by the message digest cipher + * referenced with the cipher handle is returned. + * + * Return: message digest size + */ static inline unsigned int crypto_hash_digestsize(struct crypto_hash *tfm) { return crypto_hash_crt(tfm)->digestsize; @@ -1186,11 +2226,38 @@ static inline void crypto_hash_clear_flags(struct crypto_hash *tfm, u32 flags) crypto_tfm_clear_flags(crypto_hash_tfm(tfm), flags); } +/** + * crypto_hash_init() - (re)initialize message digest handle + * @desc: cipher request handle that to be filled by caller -- + * desc.tfm is filled with the hash cipher handle; + * desc.flags is filled with either CRYPTO_TFM_REQ_MAY_SLEEP or 0. + * + * The call (re-)initializes the message digest referenced by the hash cipher + * request handle. Any potentially existing state created by previous + * operations is discarded. + * + * Return: 0 if the message digest initialization was successful; < 0 if an + * error occurred + */ static inline int crypto_hash_init(struct hash_desc *desc) { return crypto_hash_crt(desc->tfm)->init(desc); } +/** + * crypto_hash_update() - add data to message digest for processing + * @desc: cipher request handle + * @sg: scatter / gather list pointing to the data to be added to the message + * digest + * @nbytes: number of bytes to be processed from @sg + * + * Updates the message digest state of the cipher handle pointed to by the + * hash cipher request handle with the input data pointed to by the + * scatter/gather list. + * + * Return: 0 if the message digest update was successful; < 0 if an error + * occurred + */ static inline int crypto_hash_update(struct hash_desc *desc, struct scatterlist *sg, unsigned int nbytes) @@ -1198,11 +2265,39 @@ static inline int crypto_hash_update(struct hash_desc *desc, return crypto_hash_crt(desc->tfm)->update(desc, sg, nbytes); } +/** + * crypto_hash_final() - calculate message digest + * @desc: cipher request handle + * @out: message digest output buffer -- The caller must ensure that the out + * buffer has a sufficient size (e.g. by using the crypto_hash_digestsize + * function). + * + * Finalize the message digest operation and create the message digest + * based on all data added to the cipher handle. The message digest is placed + * into the output buffer. + * + * Return: 0 if the message digest creation was successful; < 0 if an error + * occurred + */ static inline int crypto_hash_final(struct hash_desc *desc, u8 *out) { return crypto_hash_crt(desc->tfm)->final(desc, out); } +/** + * crypto_hash_digest() - calculate message digest for a buffer + * @desc: see crypto_hash_final() + * @sg: see crypto_hash_update() + * @nbytes: see crypto_hash_update() + * @out: see crypto_hash_final() + * + * This function is a "short-hand" for the function calls of crypto_hash_init, + * crypto_hash_update and crypto_hash_final. The parameters have the same + * meaning as discussed for those separate three functions. + * + * Return: 0 if the message digest creation was successful; < 0 if an error + * occurred + */ static inline int crypto_hash_digest(struct hash_desc *desc, struct scatterlist *sg, unsigned int nbytes, u8 *out) @@ -1210,6 +2305,17 @@ static inline int crypto_hash_digest(struct hash_desc *desc, return crypto_hash_crt(desc->tfm)->digest(desc, sg, nbytes, out); } +/** + * crypto_hash_setkey() - set key for message digest + * @hash: cipher handle + * @key: buffer holding the key + * @keylen: length of the key in bytes + * + * The caller provided key is set for the message digest cipher. The cipher + * handle must point to a keyed hash in order for this function to succeed. + * + * Return: 0 if the setting of the key was successful; < 0 if an error occurred + */ static inline int crypto_hash_setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen) { |