From 39a8883a2b989d1d21bd8dd99f5557f0c5e89694 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Tue, 17 Jul 2018 18:24:27 -0400 Subject: random: add a config option to trust the CPU's hwrng This gives the user building their own kernel (or a Linux distribution) the option of deciding whether or not to trust the CPU's hardware random number generator (e.g., RDRAND for x86 CPU's) as being correctly implemented and not having a back door introduced (perhaps courtesy of a Nation State's law enforcement or intelligence agencies). This will prevent getrandom(2) from blocking, if there is a willingness to trust the CPU manufacturer. Signed-off-by: Theodore Ts'o --- drivers/char/Kconfig | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'drivers/char/Kconfig') diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 212f447938ae..ce277ee0a28a 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -554,3 +554,17 @@ config ADI endmenu +config RANDOM_TRUST_CPU + bool "Trust the CPU manufacturer to initialize Linux's CRNG" + depends on X86 || S390 || PPC + default n + help + Assume that CPU manufacturer (e.g., Intel or AMD for RDSEED or + RDRAND, IBM for the S390 and Power PC architectures) is trustworthy + for the purposes of initializing Linux's CRNG. Since this is not + something that can be independently audited, this amounts to trusting + that CPU manufacturer (perhaps with the insistence or mandate + of a Nation State's intelligence or law enforcement agencies) + has not installed a hidden back door to compromise the CPU's + random number generation facilities. + -- cgit v1.2.3