nvme-auth: host: use crypto library in nvme_auth_dhchap_setup_host_response()

For the HMAC computation in nvme_auth_dhchap_setup_host_response(), use
the crypto library instead of crypto_shash.  This is simpler, faster,
and more reliable.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
index 47a1525e876e0ae70c28b56127a6f0becf439576..f22f17ad7e2f4868b8485a15f6963c5229dc9698 100644 (file)
--- a/drivers/nvme/host/auth.c
+++ b/drivers/nvme/host/auth.c
@@ -434,7 +434,7 @@ static int nvme_auth_set_dhchap_failure2_data(struct nvme_ctrl *ctrl,
 static int nvme_auth_dhchap_setup_host_response(struct nvme_ctrl *ctrl,
                struct nvme_dhchap_queue_context *chap)
 {
-       SHASH_DESC_ON_STACK(shash, chap->shash_tfm);
+       struct nvme_auth_hmac_ctx hmac;
        u8 buf[4], *challenge = chap->c1;
        int ret;
 
@@ -454,13 +454,11 @@ static int nvme_auth_dhchap_setup_host_response(struct nvme_ctrl *ctrl,
                        __func__, chap->qid);
        }
 
-       ret = crypto_shash_setkey(chap->shash_tfm,
-                       chap->transformed_key->key, chap->transformed_key->len);
-       if (ret) {
-               dev_warn(ctrl->device, "qid %d: failed to set key, error %d\n",
-                        chap->qid, ret);
+       ret = nvme_auth_hmac_init(&hmac, chap->hash_id,
+                                 chap->transformed_key->key,
+                                 chap->transformed_key->len);
+       if (ret)
                goto out;
-       }
 
        if (chap->dh_tfm) {
                challenge = kmalloc(chap->hash_len, GFP_KERNEL);
@@ -477,44 +475,29 @@ static int nvme_auth_dhchap_setup_host_response(struct nvme_ctrl *ctrl,
                        goto out;
        }
 
-       shash->tfm = chap->shash_tfm;
-       ret = crypto_shash_init(shash);
-       if (ret)
-               goto out;
-       ret = crypto_shash_update(shash, challenge, chap->hash_len);
-       if (ret)
-               goto out;
+       nvme_auth_hmac_update(&hmac, challenge, chap->hash_len);
+
        put_unaligned_le32(chap->s1, buf);
-       ret = crypto_shash_update(shash, buf, 4);
-       if (ret)
-               goto out;
+       nvme_auth_hmac_update(&hmac, buf, 4);
+
        put_unaligned_le16(chap->transaction, buf);
-       ret = crypto_shash_update(shash, buf, 2);
-       if (ret)
-               goto out;
+       nvme_auth_hmac_update(&hmac, buf, 2);
+
        *buf = chap->sc_c;
-       ret = crypto_shash_update(shash, buf, 1);
-       if (ret)
-               goto out;
-       ret = crypto_shash_update(shash, "HostHost", 8);
-       if (ret)
-               goto out;
-       ret = crypto_shash_update(shash, ctrl->opts->host->nqn,
-                                 strlen(ctrl->opts->host->nqn));
-       if (ret)
-               goto out;
+       nvme_auth_hmac_update(&hmac, buf, 1);
+       nvme_auth_hmac_update(&hmac, "HostHost", 8);
+       nvme_auth_hmac_update(&hmac, ctrl->opts->host->nqn,
+                             strlen(ctrl->opts->host->nqn));
        memset(buf, 0, sizeof(buf));
-       ret = crypto_shash_update(shash, buf, 1);
-       if (ret)
-               goto out;
-       ret = crypto_shash_update(shash, ctrl->opts->subsysnqn,
-                           strlen(ctrl->opts->subsysnqn));
-       if (ret)
-               goto out;
-       ret = crypto_shash_final(shash, chap->response);
+       nvme_auth_hmac_update(&hmac, buf, 1);
+       nvme_auth_hmac_update(&hmac, ctrl->opts->subsysnqn,
+                             strlen(ctrl->opts->subsysnqn));
+       nvme_auth_hmac_final(&hmac, chap->response);
+       ret = 0;
 out:
        if (challenge != chap->c1)
                kfree(challenge);
+       memzero_explicit(&hmac, sizeof(hmac));
        return ret;
 }