Commit 1471f09f authored by Herbert Xu's avatar Herbert Xu
Browse files

Revert "crypto: drbg - use memzero_explicit() for clearing sensitive data" 


    
This reverts commit 421d82f5.

None of the data zeroed are on the stack so the compiler cannot
optimise them away.
    
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 2f375538

crypto/drbg.c

+11 −12
Original line number Diff line number Diff line
@@ -98,7 +98,6 @@ 
 */



#include <crypto/drbg.h>

#include <linux/string.h>



/***************************************************************

 * Backend cipher definitions available to DRBG
@@ -491,9 +490,9 @@ static int drbg_ctr_df(struct drbg_state *drbg, 
	ret = 0;



out:

	memzero_explicit(iv, drbg_blocklen(drbg));

	memzero_explicit(temp, drbg_statelen(drbg));

	memzero_explicit(pad, drbg_blocklen(drbg));

	memset(iv, 0, drbg_blocklen(drbg));

	memset(temp, 0, drbg_statelen(drbg));

	memset(pad, 0, drbg_blocklen(drbg));

	return ret;

}
@@ -567,9 +566,9 @@ static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, 
	ret = 0;



out:

	memzero_explicit(temp, drbg_statelen(drbg) + drbg_blocklen(drbg));

	memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg));

	if (2 != reseed)

		memzero_explicit(df_data, drbg_statelen(drbg));

		memset(df_data, 0, drbg_statelen(drbg));

	return ret;

}
@@ -627,7 +626,7 @@ static int drbg_ctr_generate(struct drbg_state *drbg, 
		len = ret;



out:

	memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg));

	memset(drbg->scratchpad, 0, drbg_blocklen(drbg));

	return len;

}
@@ -865,7 +864,7 @@ static int drbg_hash_df(struct drbg_state *drbg, 
	}



out:

	memzero_explicit(tmp, drbg_blocklen(drbg));

	memset(tmp, 0, drbg_blocklen(drbg));

	return ret;

}
@@ -909,7 +908,7 @@ 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:

	memzero_explicit(drbg->scratchpad, drbg_statelen(drbg));

	memset(drbg->scratchpad, 0, drbg_statelen(drbg));

	return ret;

}
@@ -944,7 +943,7 @@ static int drbg_hash_process_addtl(struct drbg_state *drbg, 
		     drbg->scratchpad, drbg_blocklen(drbg));



out:

	memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg));

	memset(drbg->scratchpad, 0, drbg_blocklen(drbg));

	return ret;

}
@@ -991,7 +990,7 @@ static int drbg_hash_hashgen(struct drbg_state *drbg, 
	}



out:

	memzero_explicit(drbg->scratchpad,

	memset(drbg->scratchpad, 0,

	       (drbg_statelen(drbg) + drbg_blocklen(drbg)));

	return len;

}
@@ -1040,7 +1039,7 @@ static int drbg_hash_generate(struct drbg_state *drbg, 
	drbg_add_buf(drbg->V, drbg_statelen(drbg), u.req, 8);



out:

	memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg));

	memset(drbg->scratchpad, 0, drbg_blocklen(drbg));

	return len;

}