The first element of mAvailableAlgoArray is defined as the default
Rng algorithm to use. Don't go through the array at each RngGetRNG()
call and just return the first element of the array.
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Tested-by: Kun Qin <kun.qin@microsoft.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4151
The EFI_RNG_PROTOCOL can rely on the RngLib. The RngLib has multiple
implementations, some of them are unsafe (e.g. BaseRngLibTimerLib).
To allow the RngDxe to detect when such implementation is used,
a GetRngGuid() function was added in a previous patch.
The EFI_RNG_PROTOCOL can advertise multiple algorithms through
Guids. The PcdCpuRngSupportedAlgorithm is currently used to
advertise the RngLib in the Arm implementation.
The issues of doing that are:
- the RngLib implementation might not use CPU instructions,
cf. the BaseRngLibTimerLib
- most platforms don't set PcdCpuRngSupportedAlgorithm
A GetRngGuid() was added to the RngLib in a previous patch,
allowing to identify the algorithm implemented by the RngLib.
Make use of this function and place the unsage algorithm
at the last position in the mAvailableAlgoArray.
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Tested-by: Kun Qin <kun.qin@microsoft.com>
mAvailableAlgoArrayCount holds the count of available RNG algorithms.
In a following patch, its value will be used to prevent the
EFI_RNG_PROTOCOL to be installed if no RNG algorithm is available.
Correctly set/reset the value for all implementations.
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Bugzilla: 3668 (https://bugzilla.tianocore.org/show_bug.cgi?id=3668)
Add RngDxe support for Arm. This implementation uses the ArmTrngLib
to support the RawAlgorithm and doens't support the RNDR instruction.
To re-use the RngGetRNG(), RngGetInfo() and FreeAvailableAlgorithms()
functions, create Arm/AArch64 files which implement the arch specific
function GetAvailableAlgorithms(). Indeed, FEAT_RNG instruction is not
supported on Arm.
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Acked-by: Jiewen Yao <jiewen.yao@intel.com>
To re-use the AArch64/RngDxe.c for an Arm implementation,
rename AArch64/RngDxe.c to ArmRngDxe.c.
Acked-by: Leif Lindholm <quic_llindhol@quicinc.com>
Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
Acked-by: Jiewen Yao <jiewen.yao@intel.com>
Pierre Gondois