[CIFS] SMB3 Signing enablement

SMB3 uses a much faster method of signing (which is also better in other ways),
AES-CMAC.  With the kernel now supporting AES-CMAC since last release, we
are overdue to allow SMB3 signing (today only CIFS and SMB2 and SMB2.1,
but not SMB3 and SMB3.1 can sign) - and we need this also for checking
secure negotation and also per-share encryption (two other new SMB3 features
which we need to implement).

This patch needs some work in a few areas - for example we need to
move signing for SMB2/SMB3 from per-socket to per-user (we may be able to
use the "nosharesock" mount option in the interim for the multiuser case),
and Shirish found a bug in the earlier authentication overhaul
(setting signing flags properly) - but those can be done in followon
patches.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 9a1e37aad3b8..2d0f524ebeee 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -125,9 +125,11 @@ struct cifs_secmech {
         struct crypto_shash *hmacmd5; /* hmac-md5 hash function */
         struct crypto_shash *md5; /* md5 hash function */
         struct crypto_shash *hmacsha256; /* hmac-sha256 hash function */
+        struct crypto_shash *cmacaes; /* block-cipher based MAC function */
         struct sdesc *sdeschmacmd5;  /* ctxt to generate ntlmv2 hash, CR1 */
         struct sdesc *sdescmd5; /* ctxt to generate cifs/smb signature */
         struct sdesc *sdeschmacsha256;  /* ctxt to generate smb2 signature */
+        struct sdesc *sdesccmacaes;  /* ctxt to generate smb3 signature */
 };
 
 /* per smb session structure/fields */
@@ -538,6 +540,7 @@ struct TCP_Server_Info {
         int timeAdj;  /* Adjust for difference in server time zone in sec */
         __u64 CurrentMid;         /* multiplex id - rotating counter */
         char cryptkey[CIFS_CRYPTO_KEY_SIZE]; /* used by ntlm, ntlmv2 etc */
+        char smb3signingkey[SMB3_SIGN_KEY_SIZE]; /* for signing smb3 packets */
         /* 16th byte of RFC1001 workstation name is always null */
         char workstation_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL];
         __u32 sequence_number; /* for signing, protected by srv_mutex */