crypto: seqiv - Add compatibility support without RNG
When seqiv is used in compatibility mode, this patch allows it
to function even when an RNG Is not available. It also changes
the RNG allocation for the new explicit seqiv interface so that
we only hold a reference to the RNG during initialisation.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/seqiv.c b/crypto/seqiv.c
index 42e4ee5..122c56e 100644
--- a/crypto/seqiv.c
+++ b/crypto/seqiv.c
@@ -478,29 +478,42 @@
{
struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);
struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
+ int err;
spin_lock_init(&ctx->lock);
tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request);
- return crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
- crypto_ablkcipher_ivsize(geniv)) ?:
- skcipher_geniv_init(tfm);
+ err = 0;
+ if (!crypto_get_default_rng()) {
+ crypto_ablkcipher_crt(geniv)->givencrypt = seqiv_givencrypt;
+ err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
+ crypto_ablkcipher_ivsize(geniv));
+ crypto_put_default_rng();
+ }
+
+ return err ?: skcipher_geniv_init(tfm);
}
static int seqiv_old_aead_init(struct crypto_tfm *tfm)
{
struct crypto_aead *geniv = __crypto_aead_cast(tfm);
struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);
+ int err;
spin_lock_init(&ctx->lock);
crypto_aead_set_reqsize(__crypto_aead_cast(tfm),
sizeof(struct aead_request));
+ err = 0;
+ if (!crypto_get_default_rng()) {
+ geniv->givencrypt = seqiv_aead_givencrypt;
+ err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
+ crypto_aead_ivsize(geniv));
+ crypto_put_default_rng();
+ }
- return crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
- crypto_aead_ivsize(geniv)) ?:
- aead_geniv_init(tfm);
+ return err ?: aead_geniv_init(tfm);
}
static int seqiv_aead_init_common(struct crypto_tfm *tfm, unsigned int reqsize)
@@ -513,8 +526,13 @@
crypto_aead_set_reqsize(geniv, sizeof(struct aead_request));
+ err = crypto_get_default_rng();
+ if (err)
+ goto out;
+
err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
crypto_aead_ivsize(geniv));
+ crypto_put_default_rng();
if (err)
goto out;
@@ -571,8 +589,6 @@
if (inst->alg.cra_ablkcipher.ivsize < sizeof(u64))
goto free_inst;
- inst->alg.cra_ablkcipher.givencrypt = seqiv_givencrypt;
-
inst->alg.cra_init = seqiv_init;
inst->alg.cra_exit = skcipher_geniv_exit;
@@ -602,8 +618,6 @@
if (inst->alg.cra_aead.ivsize < sizeof(u64))
goto free_inst;
- inst->alg.cra_aead.givencrypt = seqiv_aead_givencrypt;
-
inst->alg.cra_init = seqiv_old_aead_init;
inst->alg.cra_exit = aead_geniv_exit;
@@ -680,18 +694,11 @@
if (IS_ERR(algt))
return PTR_ERR(algt);
- err = crypto_get_default_rng();
- if (err)
- return err;
-
if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
err = seqiv_ablkcipher_create(tmpl, tb);
else
err = seqiv_aead_create(tmpl, tb);
- if (err)
- crypto_put_default_rng();
-
return err;
}
@@ -702,14 +709,10 @@
struct aead_alg *alg;
int err;
- err = crypto_get_default_rng();
- if (err)
- return err;
-
inst = aead_geniv_alloc(tmpl, tb, 0, 0);
err = PTR_ERR(inst);
if (IS_ERR(inst))
- goto put_rng;
+ goto out;
spawn = aead_instance_ctx(inst);
alg = crypto_spawn_aead_alg(spawn);
@@ -741,8 +744,6 @@
free_inst:
aead_geniv_free(inst);
-put_rng:
- crypto_put_default_rng();
goto out;
}
@@ -752,7 +753,6 @@
skcipher_geniv_free(inst);
else
aead_geniv_free(aead_instance(inst));
- crypto_put_default_rng();
}
static struct crypto_template seqiv_tmpl = {