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authorTheodore Ts'o2018-07-18 00:24:27 +0200
committerTheodore Ts'o2018-07-24 21:43:24 +0200
commit39a8883a2b989d1d21bd8dd99f5557f0c5e89694 (patch)
tree9e86c920e258b8ca73ffa3955cd82c6c1ee84cea /drivers/char/Kconfig
parentvsprintf: Add command line option debug_boot_weak_hash (diff)
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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 <tytso@mit.edu>
Diffstat (limited to 'drivers/char/Kconfig')
-rw-r--r--drivers/char/Kconfig14
1 files changed, 14 insertions, 0 deletions
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.
+