hash_setup and mac_setup used to be called hash_start and mac_start,
but we've now converged on _setup as names. Finish making the
terminology in the documentation consistent.
We've added documentation for how context objects for multi-part
operations must be initialized consistently for key policy, hash,
cipher, and MAC. Update the generator documentation to be consistent
with how we've documented the other operations.
Add new initializers for cipher operation objects and use them in our
tests and library code. Prefer using the macro initializers due to their
straightforwardness.
The struct psa_cipher_operation_s is built with a
mbedtls_cipher_context_t. The shape of mbedtls_cipher_context_t and an
initializer that works with Clang 5.0 and its
-Wmissing-field-initializers varies based on the configuration of the
library. Instead of making multiple initializers based on a maze of
ifdefs for all combinations of MBEDTLS_CIPHER_MODE_WITH_PADDING,
MBEDTLS_CMAC_C, and MBEDTLS_USE_PSA_CRYPTO, add a dummy variable to
psa_cipher_operation_s's union that encloses mbedtls_cipher_context_t.
This allows us to initialize the dummy with a Clang-approved initializer
and have it properly initialize the entire object.
Add new initializers for MAC operation objects and use them in our tests
and library code. Prefer using the macro initializers due to their
straightforwardness.
Add new initializers for hash operation objects and use them in our
tests and library code. Prefer using the macro initializers due to their
straightforwardness.
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.
Split crypto_driver.h into 4:
* crypto_driver_common.h for common definitions, not meant to be
included directly by driver code.
* crypto_accel_driver.h for drivers that work with transparent
key material.
* crypto_se_driver.h for drivers that work with opaque key
material.
* crypto_entropy_driver.h for drivers of entropy sources.
There is no code change in this commit, I only moved some code around.
Now that the type definitions that are useful for driver are in a
separate header file from the application interface function
declarations, include that header file in crypto_driver.h.
Some parts of the library, and crypto drivers, need to see key types,
algorithms, policies, etc. but not API functions. Move portable
integral types and macros to build and analyze values of these types
to a separate headers crypto_types.h and crypto_values.h.
No functional changes, code was only moved from crypto.h to the new headers.
Define psa_status_t to int32_t unconditionally. There's no reason to
refer to psa_error_t here: psa_error_t is int32_t if it's present. We
would only need a conditional definition if psa_defs.h and
psa_crypto.h used the same type name.
Keep the conditional definition of PSA_SUCCESS. Although the C
preprocessor allows a duplicate definition for a macro, it has to be
the exact same token sequence, not merely an equivalent way to build
the same value.
Some of the documentation is obsolete in its reference to key slots
when it should discuss key handles. This may require a further pass,
possibly with some reorganization of error codes.
Update the documentation of functions that modify key slots (key
material creation and psa_set_key_policy()) to discuss how they affect
storage.
This commit marks the beginning of the removal of support for direct
access to key slots. From this commit on, programs that use
psa_key_slot_t will no longer compile.
Subsequent commits will remove the now-unused legacy support in
psa_crypto.c.
Replace `psa_key_slot_t key` by `psa_key_handle_t` in function
declarations.
This is a transition period during which handles are key slot numbers
and the whole library can still be used by accessing a key slot number
without allocating a handle.
Allow use of persistent keys, including configuring them, importing and
exporting them, and destroying them.
When getting a slot using psa_get_key_slot, there are 3 scenarios that
can occur if the keys lifetime is persistent:
1. Key type is PSA_KEY_TYPE_NONE, no persistent storage entry:
- The key slot is treated as a standard empty key slot
2. Key type is PSA_KEY_TYPE_NONE, persistent storage entry exists:
- Attempt to load the key from persistent storage
3. Key type is not PSA_KEY_TYPE_NONE:
- As checking persistent storage on every use of the key could
be expensive, the persistent key is assumed to be saved in
persistent storage, the in-memory key is continued to be used.
Add missing checks for defined(MBEDTLS_MD_C) around types and
functions that require it (HMAC, HKDF, TLS12_PRF).
Add missing checks for defined(MBEDTLS_ECDSA_DETERMINISTIC) around
code that calls mbedtls_ecdsa_sign_det().
Add missing checks for defined(MBEDTLS_ECDH_C) around ECDH-specific
functions.
This commit adds KDF algorithm identifiers `PSA_ALG_TLS12_PRF(HASH)`
to the PSA crypto API. They represent the key derivation functions
used by TLS 1.2 for the PreMasterSecret->MasterSecret and
MasterSecret->KeyBlock conversions.
Use m for the bit size of the field order, not q which is
traditionally the field order.
Correct and clarify the private key representation format as has been
done for the private key and ECDH shared secret formats.
The endianness actually depends on the curve type.
Correct the terminology around "curve size" and "order of the curve".
I tried to find a formulation that is comprehensible to programmers
who do not know the underlying mathematics, but nonetheless correct
and precise.
Use similar terminology in other places that were using "order of the
curve" to describe the bit size associated with the curve.
psa_key_derivation requires the caller to specify a maximum capacity.
This commit adds a special value that indicates that the maximum
capacity should be the maximum supported by the algorithm. This is
currently meant only for selection algorithms used on the shared
secret produced by a key agreement.
A key selection algorithm is similar to a key derivation algorithm in
that it takes a secret input and produces a secret output stream.
However, unlike key derivation algorithms, there is no expectation
that the input cannot be reconstructed from the output. Key selection
algorithms are exclusively meant to be used on the output of a key
agreement algorithm to select chunks of the shared secret.
Change the import/export format of private elliptic curve keys from
RFC 5915 to the raw secret value. This commit updates the format
specification and the import code, but not the export code.
Add extern "C" wrappers around type and function declarations to enable C++
interoperability of the driver header. This is done so that the driver
functions and types can be used or implmented by C++ code.
Convert PSA Crypto driver model structs to typedefs so that the `struct`
name doesn't need to be used and for consistent style with other PSA
structures.
The file crypto_driver.h was not using the header guard style as other PSA
Crypto header files. Remove the `__` prefix and suffix. Use C-style
comments for the end-of-guard comment.
The driver model's "encrypt or decrypt" type, encrypt_or_decrypt_t, is
publicly exposed and needs to have a `psa_` prefix in order to properly
communicate that it is part of the PSA driver model.
The `pcd_` prefix is ambiguous and does not make it clear that the types
and symbols are standardized by PSA. Replace `pcd_` with a prefix that can
be shared with all PSA drivers, `psa_drv_`.
"Driver APIs" can be interpreted to mean APIs used when you want to write a
driver, not the set of functions you implement to make a driver. See
https://www.kernel.org/doc/html/latest/driver-api/index.html "The kernel
offers a wide variety of interfaces to support the development of device
drivers."
As such, we are renaming "Driver API" to "Driver Model" and updating our
work so far to reflect this change.
Add comments noting that the maximum length of a MAC must fit in
PSA_ALG_MAC_TRUNCATION_MASK. Add a unit test that verifies that the
maximum MAC size fits.
None of the currently defined MAC algorithms have a MAC size that
depends on the key size, so the key_bits parameter is unused. The
key_type parameter may be unused on an implementation where there is
no block cipher MAC. Declare the key_type and key_bits parameters as
used so that callers who define a variable just for this don't risk
getting "unused variable" warnings.
The macro was used under the name PSA_ALG_IS_BLOCK_CIPHER_MAC but
defined as PSA_ALG_IS_CIPHER_MAC. That wouldn't have worked if we used
this macro (we currently don't but it may become useful).
TLS now defines named curves in the "TLS Supported Groups registry",
but we're using the encoding only for elliptic curves, so don't
include values that aren't named curve.
While we're at it, upgrade the reference to the shiny new RFC 8422.
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.
There were only 5 categories (now 4). Reduce the category mask from 7
bits to 3.
Combine unformatted, not-necessarily-uniform keys (HMAC, derivation)
with raw data.
Reintroduce a KEY_TYPE_IS_UNSTRUCTURED macro (which used to exist
under the name KEY_TYPE_IS_RAW_DATA macro) for key types that don't
have any structure, including both should-be-uniform keys (such as
block cipher and stream cipher keys) and not-necessarily-uniform
keys (such as HMAC keys and secrets for key derivation).
