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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2014-09-05 15:52:28 +0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2014-09-05 15:52:28 +0800 |
| commit | fb38ab4cd05e11184fd2c3ef916fa106ecc505fc (patch) | |
| tree | c73708cf16a0468a0cc90f0dc6601680c3acaa8e /include | |
| parent | 7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9 (diff) | |
| download | linux-fb38ab4cd05e11184fd2c3ef916fa106ecc505fc.tar.gz linux-fb38ab4cd05e11184fd2c3ef916fa106ecc505fc.tar.bz2 linux-fb38ab4cd05e11184fd2c3ef916fa106ecc505fc.zip | |
crypto: drbg - backport "fix maximum value checks on 32 bit systems"
This is a backport of commit b9347aff91ce4789619168539f08202d8d6a1177.
This backport is needed as without it the code will crash 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: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'include')
| -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 831d786976c5..882675e7c055 100644 --- a/include/crypto/drbg.h +++ b/include/crypto/drbg.h @@ -162,12 +162,25 @@ static inline size_t drbg_max_request_bytes(struct drbg_state *drbg) static inline size_t drbg_max_addtl(struct drbg_state *drbg) { +#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<<(drbg->core->max_addtllen)); +#endif } static inline size_t drbg_max_requests(struct drbg_state *drbg) { +#if (__BITS_PER_LONG == 32) + return SIZE_MAX; +#else return (1UL<<(drbg->core->max_req)); +#endif } /* |