This patch adds support for non-volatile counter authentication to
the Authentication Module. This method consists of matching the
counter values provided in the certificates with the ones stored
in the platform. If the value from the certificate is lower than
the platform, the boot process is aborted. This mechanism protects
the system against rollback.
The TBBR CoT has been updated to include this method as part of the
authentication process. Two counters are used: one for the trusted
world images and another for the non trusted world images.
** NEW PLATFORM APIs (mandatory when TBB is enabled) **
int plat_get_nv_ctr(void *cookie, unsigned int *nv_ctr);
This API returns the non-volatile counter value stored
in the platform. The cookie in the first argument may be
used to select the counter in case the platform provides
more than one (i.e. TBSA compliant platforms must provide
trusted and non-trusted counters). This cookie is specified
in the CoT.
int plat_set_nv_ctr(void *cookie, unsigned int nv_ctr);
This API sets a new counter value. The cookie may be
used to select the counter to be updated.
An implementation of these new APIs for ARM platforms is also
provided. The values are obtained from the Trusted Non-Volatile
Counters peripheral. The cookie is used to pass the extension OID.
This OID may be interpreted by the platform to know which counter
must return. On Juno, The trusted and non-trusted counter values
have been tied to 31 and 223, respectively, and cannot be modified.
** IMPORTANT **
THIS PATCH BREAKS THE BUILD WHEN TRUSTED_BOARD_BOOT IS ENABLED. THE
NEW PLATFORM APIs INTRODUCED IN THIS PATCH MUST BE IMPLEMENTED IN
ORDER TO SUCCESSFULLY BUILD TF.
Change-Id: Ic943b76b25f2a37f490eaaab6d87b4a8b3cbc89a
By default ARM TF is built with the '-pedantic' compiler flag, which
helps detecting violations of the C standard. However, the mbed TLS
library and its associated authentication module in TF used to fail
building with this compiler flag. As a workaround, the mbed TLS
authentication module makefile used to set the 'DISABLE_PEDANTIC'
TF build flag.
The compiler errors flagged by '-pedantic' in the mbed TLS library
have been fixed between versions 1.3.9 and 2.2.0 and the library now
properly builds with this compiler flag.
This patch fixes the remaining compiler errors in the mbed TLS
authentication module in TF and unsets the 'DISABLE_PEDANTIC' TF
build flag. This means that TF is now always built with '-pedantic'.
In particular, this patch:
* Removes the final semi-colon in REGISTER_COT() macro.
This semi-colon was causing the following error message:
drivers/auth/tbbr/tbbr_cot.c:544:23: error: ISO C does not allow
extra ';' outside of a function [-Werror=pedantic]
This has been fixed both in the mbed TLS authentication module
as well as in the certificate generation tool. Note that the latter
code didn't need fixing since it is not built with '-pedantic' but
the change has been propagated for consistency.
Also fixed the REGISTER_KEYS() and REGISTER_EXTENSIONS() macros,
which were suffering from the same issue.
* Fixes a pointer type.
It was causing the following error message:
drivers/auth/mbedtls/mbedtls_crypto.c: In function 'verify_hash':
drivers/auth/mbedtls/mbedtls_crypto.c:177:42: error: pointer of
type 'void *' used in arithmetic [-Werror=pointer-arith]
Change-Id: I7b7a04ef711efd65e17b5be26990d1a0d940257d
The mbed TLS library has introduced some changes in the API from
the 1.3.x to the 2.x releases. Using the 2.x releases requires
some changes to the crypto and transport modules.
This patch updates both modules to the mbed TLS 2.x API.
All references to the mbed TLS library in the code or documentation
have been updated to 'mbed TLS'. Old references to PolarSSL have
been updated to 'mbed TLS'.
User guide updated to use mbed TLS 2.2.0.
NOTE: moving up to mbed TLS 2.x from 1.3.x is not backward compatible.
Applying this patch will require an mbed TLS 2.x release to be used.
Also note that the mbed TLS license changed to Apache version 2.0.
Change-Id: Iba4584408653cf153091f2ca2ee23bc9add7fda4
This patch adds the following mbedTLS based libraries:
* Cryptographic library
It is used by the crypto module to verify a digital signature
and a hash. This library relies on mbedTLS to perform the
cryptographic operations. mbedTLS sources must be obtained
separately.
Two key algorithms are currently supported:
* RSA-2048
* ECDSA-SECP256R1
The platform is responsible for picking up the required
algorithm by defining the 'MBEDTLS_KEY_ALG' variable in the
platform makefile. Available options are:
* 'rsa' (for RSA-2048) (default option)
* 'ecdsa' (for ECDSA-SECP256R1)
Hash algorithm currently supported is SHA-256.
* Image parser library
Used by the image parser module to extract the authentication
parameters stored in X509v3 certificates.
Change-Id: I597c4be3d29287f2f18b82846973afc142ee0bf0
Juan Castillo
Sandrine Bailleux