The maximum values for additional input string or generated blocks is
larger than 1<<32. To ensure a sensible value on 32 bit systems, return
SIZE_MAX on 32 bit systems. This value is lower than the maximum
allowed values defined in SP800-90A. The standard allow lower maximum
values, but not larger values.
SIZE_MAX - 1 is used for drbg_max_addtl to allow
drbg_healthcheck_sanity to check the enforcement of the variable
without wrapping.
Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx>
---
include/crypto/drbg.h | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/include/crypto/drbg.h b/include/crypto/drbg.h
index 3d8e73a..5186f75 100644
--- a/include/crypto/drbg.h
+++ b/include/crypto/drbg.h
@@ -154,13 +154,26 @@ static inline size_t drbg_max_request_bytes(struct drbg_state *drbg)
static inline size_t drbg_max_addtl(struct drbg_state *drbg)
{
/* SP800-90A requires 2**35 bytes additional info str / pers str */
+#if (__BITS_PER_LONG == 32)
+ /*
+ * SP800-90A allows smaller maximum numbers to be returned -- we
+ * return SIZE_MAX - 1 to allow the verification of the enforcement
+ * of this value in drbg_healthcheck_sanity.
+ */
+ return (SIZE_MAX - 1);
+#else
return (1UL<<35);
+#endif
}
static inline size_t drbg_max_requests(struct drbg_state *drbg)
{
/* SP800-90A requires 2**48 maximum requests before reseeding */
+#if (__BITS_PER_LONG == 32)
+ return SIZE_MAX;
+#else
return (1UL<<48);
+#endif
}
/*
--
1.9.3
--
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