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| author | Stephan Mueller <smueller@chronox.de> | 2014-08-26 12:29:45 +0400 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2014-08-26 12:58:05 +0400 |
| commit | b9347aff91ce4789619168539f08202d8d6a1177 (patch) | |
| tree | d38c52fb8408e6ce77cc61735c2f68d8a2e1b949 | |
| parent | 7c8ae03f41e635813b777a0989d8ac1ff5a8494e (diff) | |
| download | linux-b9347aff91ce4789619168539f08202d8d6a1177.tar.xz | |
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>
| -rw-r--r-- | include/crypto/drbg.h | 13 |
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 } /* |