From: Vlad-Andrei BĂDOIU (78692) <vlad_andrei.badoiu@xxxxxxxxxxxxxxx>
This patch adds a new function, _get_random_seed32 for seed generaton. If the
pre-compiled config option is not selected, then rdrand is used on x86 and
ukplat_wall_clock on ARM.
Signed-off-by: Vlad-Andrei Badoiu <vlad_andrei.badoiu@xxxxxxxxxxxxxxx>
---
lib/ukswrand/Config.uk | 22 +++++++++++++++++++---
lib/ukswrand/exportsyms.uk | 1 +
lib/ukswrand/include/uk/swrand.h | 5 ++++-
lib/ukswrand/mwc.c | 11 ++++++-----
lib/ukswrand/swrand.c | 29 ++++++++++++++++++++++++++++-
5 files changed, 58 insertions(+), 10 deletions(-)
diff --git a/lib/ukswrand/Config.uk b/lib/ukswrand/Config.uk
index c58371bb..e056b4c5 100644
--- a/lib/ukswrand/Config.uk
+++ b/lib/ukswrand/Config.uk
@@ -14,9 +14,25 @@ config LIBUKSWRAND_MWC
Use multiply-with-carry algorithm
endchoice
-config LIBUKSWRAND_INITIALSEED
- int "Initial random seed"
- default 23
+choice
+ prompt "Initial seed"
+ default LIBUKSWRANDR_INITIALSEED_TIME
+
+config LIBUKSWRAND_INITIALSEED_TIME
+ bool "Platform timestamp"
+
+config LIBUKSWRAND_INITIALSEED_RDRAND
+ depends on ARCH_X86_64 && (MARCH_X86_64_COREI7AVXI)
+ bool "`rdrand` instruction"
+
+config LIBUKSWRAND_INITIALSEED_USECONSTANT
+ bool "Compiled-in constant"
+endchoice
+
+config LIBUKSWRAND_INITIALSEED_CONSTANT
+ int "Initial seed constant"
+ depends on LIBUKSWRAND_INITIALSEED_USECONSTANT
+ default 23
config LIBUKSWRAND_DEVFS
bool "Register random and urandom device to devfs"
diff --git a/lib/ukswrand/exportsyms.uk b/lib/ukswrand/exportsyms.uk
index 49744046..40739365 100644
--- a/lib/ukswrand/exportsyms.uk
+++ b/lib/ukswrand/exportsyms.uk
@@ -2,3 +2,4 @@ getrandom
uk_swrand_def
uk_swrand_init_r
uk_swrand_randr_r
+uk_swrandr_gen_seed32
diff --git a/lib/ukswrand/include/uk/swrand.h b/lib/ukswrand/include/uk/swrand.h
index 35f3e2fe..29be8a9b 100644
--- a/lib/ukswrand/include/uk/swrand.h
+++ b/lib/ukswrand/include/uk/swrand.h
@@ -39,6 +39,7 @@
#include <uk/arch/types.h>
#include <uk/plat/lcpu.h>
#include <uk/config.h>
+#include <uk/plat/time.h>
#ifdef __cplusplus
extern "C" {
@@ -48,9 +49,11 @@ struct uk_swrand;
extern struct uk_swrand uk_swrand_def;
-void uk_swrand_init_r(struct uk_swrand *r, __u32 seed);
+void uk_swrand_init_r(struct uk_swrand *r, unsigned int seedc,
+ const __u32 seedv[]);
__u32 uk_swrand_randr_r(struct uk_swrand *r);
+__u32 uk_swrandr_gen_seed32(void);
/* Uses the pre-initialized default generator */
/* TODO: Add assertion when we can test if we are in interrupt context */
/* TODO: Revisit with multi-CPU support */
diff --git a/lib/ukswrand/mwc.c b/lib/ukswrand/mwc.c
index 8b4cca30..f032e950 100644
--- a/lib/ukswrand/mwc.c
+++ b/lib/ukswrand/mwc.c
@@ -48,15 +48,17 @@ struct uk_swrand {
struct uk_swrand uk_swrand_def;
-void uk_swrand_init_r(struct uk_swrand *r, __u32 seed)
+void uk_swrand_init_r(struct uk_swrand *r, unsigned int seedc,
+ const __u32 seedv[])
{
__u32 i;
UK_ASSERT(r);
+ UK_ASSERT(seedc > 0);
- r->Q[0] = seed;
- r->Q[1] = seed + PHI;
- r->Q[2] = seed + PHI + PHI;
+ r->Q[0] = seedv[0];
+ r->Q[1] = seedv[0] + PHI;
+ r->Q[2] = seedv[0] + PHI + PHI;
for (i = 3; i < 4096; i++)
r->Q[i] = r->Q[i - 3] ^ r->Q[i - 2] ^ PHI ^ i;
@@ -88,4 +90,3 @@ __u32 uk_swrand_randr_r(struct uk_swrand *r)
r->c = c;
return (r->Q[i] = y - x);
}
-
diff --git a/lib/ukswrand/swrand.c b/lib/ukswrand/swrand.c
index d9497bf8..b3f410fb 100644
--- a/lib/ukswrand/swrand.c
+++ b/lib/ukswrand/swrand.c
@@ -37,6 +37,26 @@
#define UK_SWRAND_CTOR_PRIO 1
+__u32 uk_swrandr_gen_seed32(void)
+{
+ __u32 val;
+
+#ifdef CONFIG_LIBUKSWRAND_INITIALSEED_TIME
+ val = (__u32)ukplat_wall_clock();
+#endif
+
+#ifdef CONFIG_LIBUKSWRAND_INITIALSEED_RDRAND
+ asm volatile ("rdrand %%eax;"
+ : "=a" (val));
+#endif
+
+#ifdef CONFIG_LIBUKSWRAND_INITIALSEED_USECONSTANT
+ val = CONFIG_LIBUKSWRAND_INITIALSEED_CONSTANT;
+#endif
+
+ return val;
+}
+
ssize_t uk_swrand_fill_buffer(void *buf, size_t buflen)
{
size_t step, chunk_size, i;
@@ -59,8 +79,15 @@ ssize_t uk_swrand_fill_buffer(void *buf, size_t buflen)
static void _uk_swrand_ctor(void)
{
+ unsigned int i;
+ unsigned int seedc = 2;
+ __u32 seedv[2];
+
+ for (i = 0; i < seedc; i++)
+ seedv[i] = uk_swrandr_gen_seed32();
+
uk_pr_info("Initialize random number generator...\n");
- uk_swrand_init_r(&uk_swrand_def, CONFIG_LIBUKSWRAND_INITIALSEED);
+ uk_swrand_init_r(&uk_swrand_def, seedc, seedv);
}
UK_CTOR_FUNC(UK_SWRAND_CTOR_PRIO, _uk_swrand_ctor);
