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authorNickolaus Woodruff <nickolauswoodruff@gmail.com>2014-11-26 13:40:57 -0500
committerHerbert Xu <herbert@gondor.apana.org.au>2014-11-27 22:26:18 +0800
commit421d82f5b3e75f94e31875e37d45cdf6a557c120 (patch)
treedaf8400560e56d726b40b103b4d67d16a6e15c32
parent0653a7cf6fa49bc769628b6078c3ea9e1489cb7b (diff)
crypto: drbg - use memzero_explicit() for clearing sensitive data
Compiler dead store optimization can sometimes remove final calls to memset() used to clear sensitive data at the end of a function. Replace trailing memset() calls with memzero_explicit() to preclude unwanted removal. Signed-off-by: Nickolaus Woodruff <nickolauswoodruff@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--crypto/drbg.c23
1 files changed, 12 insertions, 11 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c
index c90e3cf5967f..d748a1d0ca24 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -98,6 +98,7 @@
*/
#include <crypto/drbg.h>
+#include <linux/string.h>
/***************************************************************
* Backend cipher definitions available to DRBG
@@ -497,9 +498,9 @@ static int drbg_ctr_df(struct drbg_state *drbg,
ret = 0;
out:
- memset(iv, 0, drbg_blocklen(drbg));
- memset(temp, 0, drbg_statelen(drbg));
- memset(pad, 0, drbg_blocklen(drbg));
+ memzero_explicit(iv, drbg_blocklen(drbg));
+ memzero_explicit(temp, drbg_statelen(drbg));
+ memzero_explicit(pad, drbg_blocklen(drbg));
return ret;
}
@@ -573,9 +574,9 @@ static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed,
ret = 0;
out:
- memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg));
+ memzero_explicit(temp, drbg_statelen(drbg) + drbg_blocklen(drbg));
if (2 != reseed)
- memset(df_data, 0, drbg_statelen(drbg));
+ memzero_explicit(df_data, drbg_statelen(drbg));
return ret;
}
@@ -633,7 +634,7 @@ static int drbg_ctr_generate(struct drbg_state *drbg,
len = ret;
out:
- memset(drbg->scratchpad, 0, drbg_blocklen(drbg));
+ memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg));
return len;
}
@@ -871,7 +872,7 @@ static int drbg_hash_df(struct drbg_state *drbg,
}
out:
- memset(tmp, 0, drbg_blocklen(drbg));
+ memzero_explicit(tmp, drbg_blocklen(drbg));
return ret;
}
@@ -915,7 +916,7 @@ static int drbg_hash_update(struct drbg_state *drbg, struct list_head *seed,
ret = drbg_hash_df(drbg, drbg->C, drbg_statelen(drbg), &datalist2);
out:
- memset(drbg->scratchpad, 0, drbg_statelen(drbg));
+ memzero_explicit(drbg->scratchpad, drbg_statelen(drbg));
return ret;
}
@@ -950,7 +951,7 @@ static int drbg_hash_process_addtl(struct drbg_state *drbg,
drbg->scratchpad, drbg_blocklen(drbg));
out:
- memset(drbg->scratchpad, 0, drbg_blocklen(drbg));
+ memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg));
return ret;
}
@@ -997,7 +998,7 @@ static int drbg_hash_hashgen(struct drbg_state *drbg,
}
out:
- memset(drbg->scratchpad, 0,
+ memzero_explicit(drbg->scratchpad,
(drbg_statelen(drbg) + drbg_blocklen(drbg)));
return len;
}
@@ -1046,7 +1047,7 @@ static int drbg_hash_generate(struct drbg_state *drbg,
drbg_add_buf(drbg->V, drbg_statelen(drbg), u.req, 8);
out:
- memset(drbg->scratchpad, 0, drbg_blocklen(drbg));
+ memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg));
return len;
}