The mbedTLS library requires larger heap memory for verification of RSASSA-PSS
signature in certificates during Trusted Board Boot. This patch increases the
heap memory for the same.
Change-Id: I3c3123d7142b7b7b01463516ec436734895da159
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
mbed TLS provides the debug API `mbedtls_memory_buffer_alloc_status()`
to analyse the RAM usage of the library.
When RSA is selected as algorithm, the maximum heap usage in FVP and
Juno has been determined empirically to be approximately 5.5 KiB.
However, The default heap size used when RSA is selected is 8 KiB.
This patch reduces the buffer from 8 KiB to 6 KiB so that the BSS
sections of both BL1 and BL2 are 2 KiB smaller when the firmware is
compiled with TBB support.
Change-Id: I43878a4e7af50c97be9c8d027c728c8483f24fbf
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
The Trusted Firmware uses a subset of the APIs provided by mbed TLS.
This subset internally uses `snprintf`, but the only format specifier
used is '%d', which is supported by `tf_snprintf`.
This patch makes mbed TLS use `tf_snprintf` instead of `snprintf`,
saving 3 KB in both debug and release builds when TBBR is enabled.
Change-Id: I7f992a21015930d7c0f4660e7a28ceefd60b9597
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
Platforms aligned with TBBR are supposed to use their own OIDs, but
defining the same macros with different OIDs does not provide any
value (at least technically).
For easier use of TBBR, this commit allows platforms to reuse the OIDs
obtained by ARM Ltd. This will be useful for non-ARM vendors that
do not need their own extension fields in their certificate files.
The OIDs of ARM Ltd. have been moved to include/tools_share/tbbr_oid.h
Platforms can include <tbbr_oid.h> instead of <platform_oid.h> by
defining USE_TBBR_DEFS as 1. USE_TBBR_DEFS is 0 by default to keep the
backward compatibility.
For clarification, I inserted a blank line between headers from the
include/ directory (#include <...>) and ones from a local directory
(#include "..." ).
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This patch renames MBEDTLS_KEY_ALG to TF_MBEDTLS_KEY_ALG. This
completes the migration of TF specific macros so that they do not
have the MBEDTLS_ suffix (see arm-trusted-firmware#874).
Change-Id: Iad7632477e220b0af987c4db3cf52229fb127d00
Signed-off-by: David Cunado <david.cunado@arm.com>
An earlier patch (arm-trusted-firmware#874) migrated MBEDTLS_ suffixed
macros to have a TBBR_ suffix to avoid any potential clash with future
mbedtls macros.
But on reflection the TBBR_ suffix could be confusing as the macros
are used to drive TF-specific configuration of mbedtls. As such
this patch migrates these macros from TBBR_suffix to TF_MBEDTLS_
suffix which more accurately conveys their use.
Change-Id: Ic87642b653ceeaa03d62f724976abd5e12e867d4
Signed-off-by: David Cunado <david.cunado@arm.com>
To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.
NOTE: Files that have been imported by FreeBSD have not been modified.
[0]: https://spdx.org/
Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
These macros are not part of mbed TLS so they should not be prefixed
with `MBEDTLS_` to avoid potential collision in the future. Use the
`TBBR_` suffix to highlight that they only used in TF.
`MBEDTLS_KEY_ALG` was not modified because that is documented and used
by platforms to select the key algorithm.
Change-Id: Ief224681715c481691c80810501830ce16e210b0
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
This reverts commit b621fb503c.
Because of the Trusted Firmware design, timing-safe functions are not
needed. Using them may be misleading as it could be interpreted as being
a protection against private data leakage, which isn't the case here.
For each image, the SHA-256 hash is calculated. Some padding is appended
and the result is encrypted with a private key using RSA-2048. This is
the signature of the image. The public key is stored along with BL1 in
read-only memory and the encrypted hash is stored in the FIP.
When authenticating an image, the TF decrypts the hash stored in the FIP
and recalculates the hash of the image. If they don't match, the boot
sequence won't continue.
A constant-time comparison does not provide additional security as all
the data involved in this process is already known to any attacker.
There is no private data that can leaked through a timing attack when
authenticating an image.
`timingsafe_bcmp()` is kept in the codebase because it could be useful
in the future.
Change-Id: I44bdcd58faa586a050cc89447e38c142508c9888
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
Replace all use of memset by zeromem when zeroing moderately-sized
structure by applying the following transformation:
memset(x, 0, sizeof(x)) => zeromem(x, sizeof(x))
As the Trusted Firmware is compiled with -ffreestanding, it forbids the
compiler from using __builtin_memset and forces it to generate calls to
the slow memset implementation. Zeromem is a near drop in replacement
for this use case, with a more efficient implementation on both AArch32
and AArch64.
Change-Id: Ia7f3a90e888b96d056881be09f0b4d65b41aa79e
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
To avoid timing side-channel attacks, it is needed to use a constant
time memory comparison function when comparing hashes. The affected
code only cheks for equality so it isn't needed to use any variant of
memcmp(), bcmp() is enough.
Also, timingsafe_bcmp() is as fast as memcmp() when the two compared
regions are equal, so this change incurrs no performance hit in said
case. In case they are unequal, the boot sequence wouldn't continue as
normal, so performance is not an issue.
Change-Id: I1c7c70ddfa4438e6031c8814411fef79fd3bb4df
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
In mbedtls_x509_parser.c there are some static arrays that are filled
during the integrity check and then read whenever an authentication
parameter is requested. However, they aren't cleared in case of an
integrity check failure, which can be problematic from a security
point of view. This patch clears these arrays in the case of failure.
Change-Id: I9d48f5bc71fa13e5a75d6c45b5e34796ef13aaa2
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
This comment block says the default algorithm is ESDSA, while the
code obviously sets the default to RSA:
ifeq (${MBEDTLS_KEY_ALG},)
MBEDTLS_KEY_ALG := rsa
endif
The git log of commit 7d37aa1711 ("TBB: add mbedTLS authentication
related libraries") states available options are:
* 'rsa' (for RSA-2048) (default option)
* 'ecdsa' (for ECDSA-SECP256R1)
So, my best guess is the comment block is wrong.
The mismatch between the code and the comment is confusing. Fix it.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The previous code required that a certificate be signed with the ROT
key before the platform's NV counter could be updated with the value
in the certificate. This implies that the Non-Trusted NV counter was
not being updated for Non-Trusted content certificates, as they cannot
be signed with the ROT key in the TBBR CoT scheme.
The code is reworked to only allow updating the platform's Trusted NV
counter when a certificate protected by the Trusted NV counter is
signed with the ROT key.
Content certificates protected by the Non-Trusted NV counter are
allowed to update the platform's Non-Trusted NV counter, assuming
that the certificate value is higher than the platform's value.
A new optional platform API has been introduced, named
plat_set_nv_ctr2(). Platforms may choose to implement it and perform
additional checks based on the authentication image descriptor before
modifying the NV counters. A default weak implementation is available
that just calls into plat_set_nv_ctr().
FixesARM-software/tf-issues#426
Change-Id: I4fc978fd28a3007bc0cef972ff1f69ad0413b79c
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
A production ROM with TBB enabled must have the ability to boot test software
before a real ROTPK is deployed (e.g. manufacturing mode). Previously the
function plat_get_rotpk_info() must return a valid ROTPK for TBB to succeed.
This patch adds an additional bit `ROTPK_NOT_DEPLOYED` in the output `flags`
parameter from plat_get_rotpk_info(). If this bit is set, then the ROTPK
in certificate is used without verifying against the platform value.
FixesARM-software/tf-issues#381
Change-Id: Icbbffab6bff8ed76b72431ee21337f550d8fdbbb
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
This patch replaces all references to the SCP Firmware (BL0, BL30,
BL3-0, bl30) with the image terminology detailed in the TF wiki
(https://github.com/ARM-software/arm-trusted-firmware/wiki):
BL0 --> SCP_BL1
BL30, BL3-0 --> SCP_BL2
bl30 --> scp_bl2
This change affects code, documentation, build system, tools and
platform ports that load SCP firmware. ARM plaforms have been
updated to the new porting API.
IMPORTANT: build option to specify the SCP FW image has changed:
BL30 --> SCP_BL2
IMPORTANT: This patch breaks compatibility for platforms that use BL2
to load SCP firmware. Affected platforms must be updated as follows:
BL30_IMAGE_ID --> SCP_BL2_IMAGE_ID
BL30_BASE --> SCP_BL2_BASE
bl2_plat_get_bl30_meminfo() --> bl2_plat_get_scp_bl2_meminfo()
bl2_plat_handle_bl30() --> bl2_plat_handle_scp_bl2()
Change-Id: I24c4c1a4f0e4b9f17c9e4929da815c4069549e58
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
Firmware update(a.k.a FWU) feature is part of the TBB architecture.
BL1 is responsible for carrying out the FWU process if platform
specific code detects that it is needed.
This patch adds support for FWU feature support in BL1 which is
included by enabling `TRUSTED_BOARD_BOOT` compile time flag.
This patch adds bl1_fwu.c which contains all the core operations
of FWU, which are; SMC handler, image copy, authentication, execution
and resumption. It also adds bl1.h introducing #defines for all
BL1 SMCs.
Following platform porting functions are introduced:
int bl1_plat_mem_check(uintptr_t mem_base, unsigned int mem_size,
unsigned int flags);
This function can be used to add platform specific memory checks
for the provided base/size for the given security state.
The weak definition will invoke `assert()` and return -ENOMEM.
__dead2 void bl1_plat_fwu_done(void *cookie, void *reserved);
This function can be used to initiate platform specific procedure
to mark completion of the FWU process.
The weak definition waits forever calling `wfi()`.
plat_bl1_common.c contains weak definitions for above functions.
FWU process starts when platform detects it and return the image_id
other than BL2_IMAGE_ID by using `bl1_plat_get_next_image_id()` in
`bl1_main()`.
NOTE: User MUST provide platform specific real definition for
bl1_plat_mem_check() in order to use it for Firmware update.
Change-Id: Ice189a0885d9722d9e1dd03f76cac1aceb0e25ed
This patch adds a CoT based on the Trusted Board Boot Requirements
document*. The CoT consists of an array of authentication image
descriptors indexed by the image identifiers.
A new header file with TBBR image identifiers has been added.
Platforms that use the TBBR (i.e. ARM platforms) may reuse these
definitions as part of their platform porting.
PLATFORM PORT - IMPORTANT:
Default image IDs have been removed from the platform common
definitions file (common_def.h). As a consequence, platforms that
used those common definitons must now either include the IDs
provided by the TBBR header file or define their own IDs.
*The NVCounter authentication method has not been implemented yet.
Change-Id: I7c4d591863ef53bb0cd4ce6c52a60b06fa0102d5
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
This patch adds the authentication framework that will be used as
the base to implement Trusted Board Boot in the Trusted Firmware.
The framework comprises the following modules:
- Image Parser Module (IPM)
This module is responsible for interpreting images, check
their integrity and extract authentication information from
them during Trusted Board Boot.
The module currently supports three types of images i.e.
raw binaries, X509v3 certificates and any type specific to
a platform. An image parser library must be registered for
each image type (the only exception is the raw image parser,
which is included in the main module by default).
Each parser library (if used) must export a structure in a
specific linker section which contains function pointers to:
1. Initialize the library
2. Check the integrity of the image type supported by
the library
3. Extract authentication information from the image
- Cryptographic Module (CM)
This module is responsible for verifying digital signatures
and hashes. It relies on an external cryptographic library
to perform the cryptographic operations.
To register a cryptographic library, the library must use the
REGISTER_CRYPTO_LIB macro, passing function pointers to:
1. Initialize the library
2. Verify a digital signature
3. Verify a hash
Failing to register a cryptographic library will generate
a build time error.
- Authentication Module (AM)
This module provides methods to authenticate an image, like
hash comparison or digital signatures. It uses the image parser
module to extract authentication parameters, the crypto module
to perform cryptographic operations and the Chain of Trust to
authenticate the images.
The Chain of Trust (CoT) is a data structure that defines the
dependencies between images and the authentication methods
that must be followed to authenticate an image.
The Chain of Trust, when added, must provide a header file named
cot_def.h with the following definitions:
- COT_MAX_VERIFIED_PARAMS
Integer value indicating the maximum number of authentication
parameters an image can present. This value will be used by the
authentication module to allocate the memory required to load
the parameters in the image descriptor.
Change-Id: Ied11bd5cd410e1df8767a1df23bb720ce7e58178
Soby Mathew
Antonio Nino Diaz
Masahiro Yamada
David Cunado
dp-arm
Douglas Raillard
Juan Castillo
Sandrine Bailleux
Yatharth Kochar