diff mbox

[2/8] crypto: echainiv - Move IV seeding into init function

Message ID E1Z02UO-0001Fs-S6@gondolin.me.apana.org.au (mailing list archive)
State Accepted
Delegated to: Herbert Xu
Headers show

Commit Message

Herbert Xu June 3, 2015, 6:49 a.m. UTC 
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>
---

 crypto/echainiv.c |   30 ++++++------------------------
 1 file changed, 6 insertions(+), 24 deletions(-)

--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

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 @@  static int echainiv_decrypt(struct aead_request *req)
 	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 @@  static int echainiv_init(struct crypto_tfm *tfm)
 
 	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 @@  static int echainiv_aead_create(struct crypto_template *tmpl,
 	    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;