[SMB3.1.1] Faster crypto (GCM) for Linux kernel SMB3.1.1 mounts

[Pavel Shilovsky]

пт, 7 июн. 2019 г. в 13:23, Steve French via samba-technical
<samba-technical at lists.samba.org>:
>
> I am seeing more than double the performance of copy to Samba on
> encrypted mount with this two patch set, and 80%+ faster on copy from
> Samba server (when running Ralph's GCM capable experimental branch of
> Samba)
>
> Patches to update the kernel client (cifs.ko) attached:
>
> --
> Thanks,
>
> Steve


--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3324,7 +3324,7 @@ smb2_dir_needs_close(struct cifsFileInfo *cfile)

 static void
 fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, unsigned int orig_len,
-                  struct smb_rqst *old_rq)
+                  struct smb_rqst *old_rq, struct TCP_Server_Info *server)
 {
        struct smb2_sync_hdr *shdr =
                        (struct smb2_sync_hdr *)old_rq->rq_iov[0].iov_base;
@@ -3333,7 +3333,10 @@ fill_transform_hdr(struct smb2_transform_hdr
*tr_hdr, unsigned int orig_len,
        tr_hdr->ProtocolId = SMB2_TRANSFORM_PROTO_NUM;
        tr_hdr->OriginalMessageSize = cpu_to_le32(orig_len);
        tr_hdr->Flags = cpu_to_le16(0x01);
-       get_random_bytes(&tr_hdr->Nonce, SMB3_AES128CCM_NONCE);
+       if (server->cipher_type == SMB2_ENCRYPTION_AES128_GCM)

We only use server->cipher_type here and below. Let's pass just this
integer instead of whole server pointer to fill_transform_hdr then

+               get_random_bytes(&tr_hdr->Nonce, SMB3_AES128GCM_NONCE);
+       else
+               get_random_bytes(&tr_hdr->Nonce, SMB3_AES128CCM_NONCE);
        memcpy(&tr_hdr->SessionId, &shdr->SessionId, 8);
 }

@@ -3491,8 +3494,13 @@ crypt_message(struct TCP_Server_Info *server,
int num_rqst,
                rc = -ENOMEM;
                goto free_sg;
        }
-       iv[0] = 3;
-       memcpy(iv + 1, (char *)tr_hdr->Nonce, SMB3_AES128CCM_NONCE);
+
+       if (server->cipher_type == SMB2_ENCRYPTION_AES128_GCM)
+               memcpy(iv, (char *)tr_hdr->Nonce, SMB3_AES128GCM_NONCE);
+       else {
+               iv[0] = 3;
+               memcpy(iv + 1, (char *)tr_hdr->Nonce, SMB3_AES128CCM_NONCE);
+       }

        aead_request_set_crypt(req, sg, sg, crypt_len, iv);
        aead_request_set_ad(req, assoc_data_len);

Other than the note above looks good.

--
Best regards,
Pavel Shilovskiy