The tools in this directory are a scheme for autogenerating crypto doc support.
The central file is data/crypto_support.json, which is a JSON file that contains
the supported API levels for each crypto algorithm that has ever been supported
by Android. The categories are identified as described in the JCA.
Each algorithm has up to three properties:
name - The name of the algorithm. These are currently normalized to
all-uppercase versions, but this produces substandard results in some cases
(eg, PBEWITHHMACSHA versus PBEWithHmacSHA), so it could be improved.
supported_api_levels: The set of Android API levels that this algorithm was/is
supported for. It should be a sequence of zero or more "N" values or "N-M"
ranges separated by commas followed by a "N+" value if the algorithm is
currently supported. For example: "17+", "1-8,22+", "1-10,15,22-24".
deprecated: Whether the algorithm is unsupported at the current API level. This
is equivalent to supported_api_levels.endswith('+'), but is included for
clarity's sake.
Updating the documentation is a three-step process: get the set of supported
algorithms, update the data file, then generate HTML based on the data file.
Getting the set of supported algorithms is done using
src/java/libcore/java/security/ListProviders.java. It's important that this is
run using vogar (in mode=device, the default) rather than in an app container,
as this documentation only includes the libcore-supported crypto support, but
the Android frameworks (in particular, Android KeyStore) can add additional
support.
The data from ListProviders is fed into update_crypto_support.py, which rewrites
the data file. Any newly-added algorithms will be added to the file's data,
and any newly-removed algorithms will have their supported API levels updated.
The preceding two steps can be performed together by running
run_update_crypto_support.sh.
Finally, format_supported_algorithm_table.py reads the data file and outputs
a collection of HTML tables suitable for copying-and-pasting into the docs
to stdout.