cifs: Start using per session key for smb2/3 for signature generation

    Switch smb2 code to use per session session key and smb3 code to
    use per session signing key instead of per connection key to
    generate signatures.

    For that, we need to find a session to fetch the session key to
    generate signature to match for every request and response packet.

    We also forgo checking signature for a session setup response
    from the server.

Acked-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 5b05eb0..b5ec2a2 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -431,7 +431,7 @@
 extern int setup_ntlmv2_rsp(struct cifs_ses *, const struct nls_table *);
 extern void cifs_crypto_shash_release(struct TCP_Server_Info *);
 extern int calc_seckey(struct cifs_ses *);
-extern void generate_smb3signingkey(struct TCP_Server_Info *);
+extern int generate_smb3signingkey(struct cifs_ses *);
 
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 extern int calc_lanman_hash(const char *password, const char *cryptkey,