refactor(auth): replace plat_convert_pk
Following discussions in the reviews of the patch that introduced
plat_convert_pk() function [1], it was decided to deprecate it to
avoid weak function declaration.
A new optional function pointer convert_pk is added to crypto_lib_desc_t.
A new function crypto_mod_convert_pk() will either call
crypto_lib_desc.convert_pk() if it is defined, or do the same
as what was done by the weak function otherwise.
[1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/17174
Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: I9358867f8bfd5e96b5ee238c066877da368e43c6
diff --git a/docs/design/auth-framework.rst b/docs/design/auth-framework.rst
index 508a82f..597f955 100644
--- a/docs/design/auth-framework.rst
+++ b/docs/design/auth-framework.rst
@@ -256,7 +256,8 @@
_verify_signature,
_calc_hash,
_verify_hash,
- _auth_decrypt);
+ _auth_decrypt,
+ _convert_pk);
``_name`` must be a string containing the name of the CL. This name is used for
debugging purposes.
@@ -266,6 +267,25 @@
This function is mainly used in the ``MEASURED_BOOT`` and ``DRTM_SUPPORT``
features to calculate the hashes of various images/data.
+Optionally, a platform function can be provided to convert public key
+(_convert_pk). It is only used if the platform saves a hash of the ROTPK.
+Most platforms save the hash of the ROTPK, but some may save slightly different
+information - e.g the hash of the ROTPK plus some related information.
+Defining this function allows to transform the ROTPK used to verify
+the signature to the buffer (a platform specific public key) which
+hash is saved in OTP.
+
+.. code:: c
+
+ int (*convert_pk)(void *full_pk_ptr, unsigned int full_pk_len,
+ void **hashed_pk_ptr, unsigned int *hashed_pk_len);
+
+
+- ``full_pk_ptr``: Pointer to Distinguished Encoding Rules (DER) ROTPK.
+- ``full_pk_len``: DER ROTPK size.
+- ``hashed_pk_ptr``: to return a pointer to a buffer, which hash should be the one saved in OTP.
+- ``hashed_pk_len``: previous buffer size
+
Image Parser Module (IPM)
^^^^^^^^^^^^^^^^^^^^^^^^^