From b9347aff91ce4789619168539f08202d8d6a1177 Mon Sep 17 00:00:00 2001 From: Stephan Mueller Date: Tue, 26 Aug 2014 10:29:45 +0200 Subject: 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 Reported-by: kbuild test robot Signed-off-by: Stephan Mueller Signed-off-by: Herbert Xu --- include/crypto/drbg.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/crypto') 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 } /* -- cgit v1.2.3-58-ga151