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Diffstat (limited to 'Documentation/crypto/devel-algos.rst')
| -rw-r--r-- | Documentation/crypto/devel-algos.rst | 65 |
1 files changed, 25 insertions, 40 deletions
diff --git a/Documentation/crypto/devel-algos.rst b/Documentation/crypto/devel-algos.rst index c45c6f400dbd..f225a953ab4b 100644 --- a/Documentation/crypto/devel-algos.rst +++ b/Documentation/crypto/devel-algos.rst @@ -31,33 +31,23 @@ The counterparts to those functions are listed below. :: - int crypto_unregister_alg(struct crypto_alg *alg); - int crypto_unregister_algs(struct crypto_alg *algs, int count); + void crypto_unregister_alg(struct crypto_alg *alg); + void crypto_unregister_algs(struct crypto_alg *algs, int count); -Notice that both registration and unregistration functions do return a -value, so make sure to handle errors. A return code of zero implies -success. Any return code < 0 implies an error. +The registration functions return 0 on success, or a negative errno +value on failure. crypto_register_algs() succeeds only if it +successfully registered all the given algorithms; if it fails partway +through, then any changes are rolled back. -The bulk registration/unregistration functions register/unregister each -transformation in the given array of length count. They handle errors as -follows: - -- crypto_register_algs() succeeds if and only if it successfully - registers all the given transformations. If an error occurs partway - through, then it rolls back successful registrations before returning - the error code. Note that if a driver needs to handle registration - errors for individual transformations, then it will need to use the - non-bulk function crypto_register_alg() instead. - -- crypto_unregister_algs() tries to unregister all the given - transformations, continuing on error. It logs errors and always - returns zero. +The unregistration functions always succeed, so they don't have a +return value. Don't try to unregister algorithms that aren't +currently registered. Single-Block Symmetric Ciphers [CIPHER] --------------------------------------- -Example of transformations: aes, arc4, ... +Example of transformations: aes, serpent, ... This section describes the simplest of all transformation implementations, that being the CIPHER type used for symmetric ciphers. @@ -108,7 +98,7 @@ is also valid: Multi-Block Ciphers ------------------- -Example of transformations: cbc(aes), ecb(arc4), ... +Example of transformations: cbc(aes), chacha20, ... This section describes the multi-block cipher transformation implementations. The multi-block ciphers are used for transformations @@ -128,25 +118,20 @@ process requests that are unaligned. This implies, however, additional overhead as the kernel crypto API needs to perform the realignment of the data which may imply moving of data. -Cipher Definition With struct blkcipher_alg and ablkcipher_alg -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -Struct blkcipher_alg defines a synchronous block cipher whereas struct -ablkcipher_alg defines an asynchronous block cipher. - -Please refer to the single block cipher description for schematics of -the block cipher usage. +Cipher Definition With struct skcipher_alg +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Specifics Of Asynchronous Multi-Block Cipher -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Struct skcipher_alg defines a multi-block cipher, or more generally, a +length-preserving symmetric cipher algorithm. -There are a couple of specifics to the asynchronous interface. +Scatterlist handling +~~~~~~~~~~~~~~~~~~~~ -First of all, some of the drivers will want to use the Generic -ScatterWalk in case the hardware needs to be fed separate chunks of the -scatterlist which contains the plaintext and will contain the -ciphertext. Please refer to the ScatterWalk interface offered by the -Linux kernel scatter / gather list implementation. +Some drivers will want to use the Generic ScatterWalk in case the +hardware needs to be fed separate chunks of the scatterlist which +contains the plaintext and will contain the ciphertext. Please refer +to the ScatterWalk interface offered by the Linux kernel scatter / +gather list implementation. Hashing [HASH] -------------- @@ -174,10 +159,10 @@ are as follows: :: - int crypto_unregister_ahash(struct ahash_alg *alg); + void crypto_unregister_ahash(struct ahash_alg *alg); - int crypto_unregister_shash(struct shash_alg *alg); - int crypto_unregister_shashes(struct shash_alg *algs, int count); + void crypto_unregister_shash(struct shash_alg *alg); + void crypto_unregister_shashes(struct shash_alg *algs, int count); Cipher Definition With struct shash_alg and ahash_alg |
