Signed-off-by: Andrew Zaborowski <andrew.zaborowski@xxxxxxxxx> --- These are some notes about the template structs that can take some head-scratching to figure out from the code. Please check that this is the current intended use. --- Documentation/crypto/api-intro.txt | 40 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/Documentation/crypto/api-intro.txt b/Documentation/crypto/api-intro.txt index 8b49302..39b5caa 100644 --- a/Documentation/crypto/api-intro.txt +++ b/Documentation/crypto/api-intro.txt @@ -117,6 +117,46 @@ Also check the TODO list at the web site listed below to see what people might already be working on. +TEMPLATE ALGORITHMS + +Templates dynamically create algorithms based on algorithm names passed +as parameters. In most cases they modify how another algorithm works by +wrapping around an instance of the other algorithm and operating on its +inputs, outputs, and/or the keys. They can call the child transform's +operations in an arbitrary order. The template can convert one algorithm +type to another and may also combine multiple instances of one or +multiple algorithms. + +The following additional types are used with templates: + +* struct crypto_template + Describes the template and has methods to create actual algorithms as + crypto_instance structures. These are not instances of algorithms + (transforms), instances of the template are algorithms. The template + does not appear in /proc/crypto but the algorithms do. The struct + crypto_template does not statically determine the resulting crypto + types. + +* struct crypto_instance + Represents an instance of a template. Its first member is the + "struct crypto_alg alg" which is a dynamically created algorithm that + behaves like any other. The structure also points back to the template + used. The crypto type-specific methods and other algorithm context is + prepended to struct crypto_instance in a way that it's also prepended + to the .alg member. The children algorithm(s) used by the template + instance are pointed to by the crypto_spawn structure(s) normally + appended after the crypto_instance. + + Actual transforms are created when the context is allocated and .init_tfm + is called same as with non-template algorithms, but the .init_tfm + function will need to trigger creation of child transform(s) from the + crypto_spawn structure(s). + +* struct crypto_spawn + Links a template algorithm (crypto_instance) and a reference to one child + algorithm. + + BUGS Send bug reports to: -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
