This applies a few improvements to a commit previously included in
PR #596:
* Move functions to dump a private key to the private key classes
* Remove language option; always dumps in C format
* Add option to generate a minimal dump. This will remove extra
parameters that are present in keys generated with the `keygen`
command.
For P256 this will remove the public point, which is already
ignored by the parsing function. The resulting key dump shrinks
from 138 to 70 bytes.
For RSA it will remove the DP/DQ/QP parameters which are only
used with CRT enabled, and if not available, can be calculated at
runtime. This reduces the size of a key dump from around 1190
bytes to somewhere close to 800 bytes. A patch to the RSA parsing
routine will be added in another commit.
Signed-off-by: Fabio Utzig <utzig@apache.org>
Signed-off-by: Ioannis Konstantelias <ikonstadel@gmail.com>
Replace RSA code with one using the python 'cryptography' library. This
library is much more complete, and will make adding support for password
protected keys, and separate public keys easier.
There is, however, a significant change brought about by this change:
the private keys are stored in PKCS#8 format, instead of the raw format
that was used previously. This is a more modern format that has a few
advantages, including: supporting stronger password protection, and
allowing the key type to be determined upon read.
This tool will still support reading the old style public keys, but
other tools that use these keys will need to be updated in order to work
with the new format.
This new code has some unit tests to go along with it for some basic
sanity testing of the code.
Signed-off-by: David Brown <david.brown@linaro.org>
Ioannis Konstantelias