crypto: drbg - Embed V and C into struct drbg_state

Now that the sizes of V and C are known at compile time, embed them into
struct drbg_state rather than using separate allocations.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 34a7cbdda1f10f6fec98027f40d063c51cd52516..e62bde7aab43ff638d50fb5065a7cfe481379a0e 100644 (file)
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -142,10 +142,8 @@ enum drbg_seed_state {
 
 struct drbg_state {
        struct mutex drbg_mutex;        /* lock around DRBG */
-       unsigned char *V;       /* internal state -- 10.1.2.1 1a */
-       unsigned char *Vbuf;
-       unsigned char *C;       /* current key -- 10.1.2.1 1b */
-       unsigned char *Cbuf;
+       u8 V[DRBG_STATE_LEN];           /* internal state -- 10.1.2.1 1a */
+       u8 C[DRBG_STATE_LEN];           /* current key -- 10.1.2.1 1b */
        /* Number of RNG requests since last reseed -- 10.1.2.1 1c */
        size_t reseed_ctr;
        size_t reseed_threshold;
@@ -492,12 +490,8 @@ static inline void drbg_dealloc_state(struct drbg_state *drbg)
 {
        if (!drbg)
                return;
-       kfree_sensitive(drbg->Vbuf);
-       drbg->Vbuf = NULL;
-       drbg->V = NULL;
-       kfree_sensitive(drbg->Cbuf);
-       drbg->Cbuf = NULL;
-       drbg->C = NULL;
+       memzero_explicit(drbg->V, sizeof(drbg->V));
+       memzero_explicit(drbg->C, sizeof(drbg->C));
        drbg->reseed_ctr = 0;
        drbg->core = NULL;
 }
@@ -513,24 +507,8 @@ static inline int drbg_alloc_state(struct drbg_state *drbg)
        ret = drbg_init_hash_kernel(drbg);
        if (ret < 0)
                goto err;
-
-       drbg->Vbuf = kmalloc(DRBG_STATE_LEN + ret, GFP_KERNEL);
-       if (!drbg->Vbuf) {
-               ret = -ENOMEM;
-               goto fini;
-       }
-       drbg->V = PTR_ALIGN(drbg->Vbuf, ret + 1);
-       drbg->Cbuf = kmalloc(DRBG_STATE_LEN + ret, GFP_KERNEL);
-       if (!drbg->Cbuf) {
-               ret = -ENOMEM;
-               goto fini;
-       }
-       drbg->C = PTR_ALIGN(drbg->Cbuf, ret + 1);
-
        return 0;
 
-fini:
-       drbg_fini_hash_kernel(drbg);
 err:
        drbg_dealloc_state(drbg);
        return ret;