From: Stephan Mueller <smueller@chronox.de>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>,
linux-next@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] DRBG: fix maximum value checks on 32 bit systems
Date: Tue, 26 Aug 2014 10:29:45 +0200 [thread overview]
Message-ID: <2984929.nIbTCa5fhe@myon.chronox.de> (raw)
In-Reply-To: <20140826080858.GA4161@gondor.apana.org.au>
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>
---
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
next prev parent reply other threads:[~2014-08-26 8:29 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-26 6:14 linux-next: build warnings after merge of the crypto tree Stephen Rothwell
2014-08-26 6:38 ` Herbert Xu
2014-08-26 7:00 ` Stephan Mueller
2014-08-26 7:31 ` [PATCH] DRBG: fix bit shifting on 32 bit systems Stephan Mueller
2014-08-26 7:32 ` Herbert Xu
2014-08-26 7:37 ` Stephan Mueller
2014-08-26 8:06 ` [PATCH] DRBG: fix maximum value checks " Stephan Mueller
2014-08-26 8:08 ` Herbert Xu
2014-08-26 8:29 ` Stephan Mueller [this message]
2014-08-26 8:43 ` [PATCH v2] " Herbert Xu
2014-08-26 8:52 ` Stephan Mueller
2014-08-26 8:58 ` Herbert Xu
2014-08-26 9:36 ` Stephan Mueller
2014-08-27 13:35 ` Herbert Xu
2014-08-27 13:40 ` Stephan Mueller
2014-08-28 7:13 ` Stephan Mueller
2014-08-28 7:17 ` DRBG: remove test for uninitialized DRBG handle Stephan Mueller
2014-09-01 5:11 ` [PATCH v2] DRBG: remove check " Stephan Mueller
2014-09-03 1:33 ` Stephan Mueller
2014-09-03 23:21 ` Herbert Xu
2014-09-03 23:50 ` Stephan Mueller
2014-09-05 7:55 ` Herbert Xu
2014-09-05 11:25 ` Stephan Mueller
2014-09-05 8:13 ` Herbert Xu
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