Commit 998d6fcb authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

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: default avatarJeff Layton <jlayton@redhat.com>
Reviewed-by: default avatarShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 1f1cff0b

fs/cifs/cifsencrypt.c

+14 −2
Original line number Diff line number Diff line
@@ -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;

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