crypto: echainiv - Move IV seeding into init function
We currently do the IV seeding on the first givencrypt call in
order to conserve entropy. However, this does not work with
DRBG which cannot be called from interrupt context. In fact,
with DRBG we don't need to conserve entropy anyway. So this
patch moves the seeding into the init function.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/echainiv.c b/crypto/echainiv.c
index 62a817f..08d3336 100644
--- a/crypto/echainiv.c
+++ b/crypto/echainiv.c
@@ -187,29 +187,6 @@
return crypto_aead_decrypt(subreq);
}
-static int echainiv_encrypt_first(struct aead_request *req)
-{
- struct crypto_aead *geniv = crypto_aead_reqtfm(req);
- struct echainiv_ctx *ctx = crypto_aead_ctx(geniv);
- int err = 0;
-
- spin_lock_bh(&ctx->geniv.lock);
- if (geniv->encrypt != echainiv_encrypt_first)
- goto unlock;
-
- geniv->encrypt = echainiv_encrypt;
- err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
- crypto_aead_ivsize(geniv));
-
-unlock:
- spin_unlock_bh(&ctx->geniv.lock);
-
- if (err)
- return err;
-
- return echainiv_encrypt(req);
-}
-
static int echainiv_init(struct crypto_tfm *tfm)
{
struct crypto_aead *geniv = __crypto_aead_cast(tfm);
@@ -220,6 +197,11 @@
crypto_aead_set_reqsize(geniv, sizeof(struct aead_request));
+ err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
+ crypto_aead_ivsize(geniv));
+ if (err)
+ goto out;
+
ctx->null = crypto_get_default_null_skcipher();
err = PTR_ERR(ctx->null);
if (IS_ERR(ctx->null))
@@ -272,7 +254,7 @@
inst->alg.ivsize > MAX_IV_SIZE)
goto free_inst;
- inst->alg.encrypt = echainiv_encrypt_first;
+ inst->alg.encrypt = echainiv_encrypt;
inst->alg.decrypt = echainiv_decrypt;
inst->alg.base.cra_init = echainiv_init;