diff options
| author | Steve French <stfrench@microsoft.com> | 2020-10-15 00:14:47 -0500 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2020-10-19 15:08:42 -0500 |
| commit | 511ac89e591ab9affce17a8be4c45f6c2bb837f0 (patch) | |
| tree | f46c4611dbb8eede037d91e093c1f6e621550360 /fs/cifs | |
| parent | 29e279230413cdd5e00fb5d269cae1099184ab85 (diff) | |
smb3.1.1: print warning if server does not support requested encryption type
If server does not support AES-256-GCM and it was required on mount, print
warning message. Also log and return a different error message (EOPNOTSUPP)
when encryption mechanism is not supported vs the case when an unknown
unrequested encryption mechanism could be returned (EINVAL).
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Diffstat (limited to 'fs/cifs')
| -rw-r--r-- | fs/cifs/smb2pdu.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 8cfc3122ae5c..d504bc296349 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -610,8 +610,19 @@ static int decode_encrypt_ctx(struct TCP_Server_Info *server, return -EINVAL; } cifs_dbg(FYI, "SMB311 cipher type:%d\n", le16_to_cpu(ctxt->Ciphers[0])); - if ((ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_CCM) && - (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_GCM)) { + if (require_gcm_256) { + if (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES256_GCM) { + cifs_dbg(VFS, "Server does not support requested encryption type (AES256 GCM)\n"); + return -EOPNOTSUPP; + } + } else if (ctxt->Ciphers[0] == 0) { + /* e.g. if server only supported AES256_CCM (very unlikely) */ + cifs_dbg(VFS, "Server does not support requested encryption types\n"); + return -EOPNOTSUPP; + } else if ((ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_CCM) && + (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_GCM) && + (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES256_GCM)) { + /* server returned a cipher we didn't ask for */ pr_warn_once("Invalid SMB3.11 cipher returned\n"); return -EINVAL; } |