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authorStephan Mueller <smueller@chronox.de>2014-08-26 10:29:45 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2014-08-26 16:58:05 +0800
commitb9347aff91ce4789619168539f08202d8d6a1177 (patch)
treed38c52fb8408e6ce77cc61735c2f68d8a2e1b949 /include/crypto
parent7c8ae03f41e635813b777a0989d8ac1ff5a8494e (diff)
downloadlinux-b9347aff91ce4789619168539f08202d8d6a1177.tar.bz2
crypto: drbg - fix maximum value checks on 32 bit systems
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@canb.auug.org.au> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'include/crypto')
-rw-r--r--include/crypto/drbg.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/crypto/drbg.h b/include/crypto/drbg.h
index 3d8e73a1a1c7..5186f750c713 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
}
/*