From 998d6fcb24d25b7889ec39118cf98d5089ac4c11 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 26 Jul 2011 12:21:17 -0400 Subject: [PATCH] cifs: don't start signing too early Sniffing traffic on the wire shows that windows clients send a zeroed out signature field in a NEGOTIATE request, and send "BSRSPYL" in the signature field during SESSION_SETUP. Make the cifs client behave the same way. It doesn't seem to make much difference in any server that I've tested against, but it's probably best to follow windows behavior as closely as possible here. Signed-off-by: Jeff Layton Reviewed-by: Shirish Pargaonkar Signed-off-by: Steve French --- fs/cifs/cifsencrypt.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c index 259991bd2112..e76bfeb68267 100644 --- a/fs/cifs/cifsencrypt.c +++ b/fs/cifs/cifsencrypt.c @@ -87,9 +87,15 @@ int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server, if ((cifs_pdu == NULL) || (server == NULL)) return -EINVAL; - if ((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0) + if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) || + server->tcpStatus == CifsNeedNegotiate) return rc; + if (!server->session_estab) { + strncpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8); + return rc; + } + cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number); cifs_pdu->Signature.Sequence.Reserved = 0; @@ -178,9 +184,15 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server, if ((cifs_pdu == NULL) || (server == NULL)) return -EINVAL; - if ((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0) + if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) || + server->tcpStatus == CifsNeedNegotiate) return rc; + if (!server->session_estab) { + strncpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8); + return rc; + } + cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number); cifs_pdu->Signature.Sequence.Reserved = 0; -- 2.20.1