When `MBEDTLS_PLATFORM_C` is not enabled, our PSA Crypto implementation
depends on the standard C library for functions like snprintf() and
exit(). However, our implementation was not including the proper header
files nor redefining all `mbedtls_*` symbols properly to ensure
successful builds without MBEDTLS_PLATFORM_C. Add the necessary header
files and macro definitions to our PSA Crypto implementation.
When MBEDTLS_CHECK_PARAMS is enabled, it's required to have an
implementation of mbedtls_param_failed() present. Without it in the PSA
examples, building the PSA examples will result in linker errors like
the following.
../../library/libmbedcrypto.a(rsa.c.o): In function `mbedtls_rsa_import':
rsa.c:(.text+0x9fd): undefined reference to `mbedtls_param_failed'
../../library/libmbedcrypto.a(rsa.c.o): In function `mbedtls_rsa_import_raw':
rsa.c:(.text+0xb0b): undefined reference to `mbedtls_param_failed'
../../library/libmbedcrypto.a(rsa.c.o): In function `mbedtls_rsa_complete':
rsa.c:(.text+0xe63): undefined reference to `mbedtls_param_failed'
../../library/libmbedcrypto.a(rsa.c.o): In function `mbedtls_rsa_export_raw':
rsa.c:(.text+0xfee): undefined reference to `mbedtls_param_failed'
../../library/libmbedcrypto.a(rsa.c.o): In function `mbedtls_rsa_export':
rsa.c:(.text+0x116f): undefined reference to `mbedtls_param_failed'
../../library/libmbedcrypto.a(rsa.c.o):rsa.c:(.text+0x1304): more undefined
references to `mbedtls_param_failed' follow
collect2: error: ld returned 1 exit status
programs/psa/CMakeFiles/crypto_examples.dir/build.make:97: recipe for target
'programs/psa/crypto_examples' failed
make[2]: *** [programs/psa/crypto_examples] Error 1
Add an implementation of mbedtls_param_failed() to the PSA Crypto
examples to avoid getting this error on the PSA examples.
Remove the type and bits arguments to psa_allocate_key() and
psa_create_key(). They can be useful if the implementation wants to
know exactly how much space to allocate for the slot, but many
implementations (including ours) don't care, and it's possible to work
around their lack by deferring size-dependent actions to the time when
the key material is created. They are a burden to applications and
make the API more complex, and the benefits aren't worth it.
Change the API and adapt the implementation, the units test and the
sample code accordingly.
Add new initializers for key policies and use them in our docs, example
programs, tests, and library code. Prefer using the macro initializers
due to their straightforwardness.
OFB and CFB are streaming modes. XTS is a not a cipher mode but it
doesn't use a separate padding step. This leaves only CBC as a block
cipher mode that needs a padding step.
Since CBC is the only mode that uses a separate padding step, and is
likely to remain the only mode in the future, encode the padding mode
directly in the algorithm constant, rather than building up an
algorithm value from a chaining mode and a padding mode. This greatly
simplifies the interface as well as some parts of the implementation.
