linux-kernel - [PATCH 4.13 27/43] Fix encryption labels and lengths for SMB3.1.1

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Message-Id: <20171031095531.596396094@linuxfoundation.org>
Date:   Tue, 31 Oct 2017 10:55:47 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Steve French <smfrench@...il.com>
Subject: [PATCH 4.13 27/43] Fix encryption labels and lengths for SMB3.1.1

4.13-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Steve French <smfrench@...il.com>

commit 06e2290844fa408d3295ac03a1647f0798518ebe upstream.

SMB3.1.1 is most secure and recent dialect. Fixup labels and lengths
for sMB3.1.1 signing and encryption.

Signed-off-by: Steve French <smfrench@...il.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 fs/cifs/cifsglob.h      |    8 ++++++--
 fs/cifs/smb2transport.c |   26 ++++++++++++++------------
 2 files changed, 20 insertions(+), 14 deletions(-)

--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -661,7 +661,9 @@ struct TCP_Server_Info {
 #endif
 	unsigned int	max_read;
 	unsigned int	max_write;
-	__u8		preauth_hash[512];
+#ifdef CONFIG_CIFS_SMB311
+	__u8	preauth_sha_hash[64]; /* save initital negprot hash */
+#endif /* 3.1.1 */
 	struct delayed_work reconnect; /* reconnect workqueue job */
 	struct mutex reconnect_mutex; /* prevent simultaneous reconnects */
 	unsigned long echo_interval;
@@ -849,7 +851,9 @@ struct cifs_ses {
 	__u8 smb3signingkey[SMB3_SIGN_KEY_SIZE];
 	__u8 smb3encryptionkey[SMB3_SIGN_KEY_SIZE];
 	__u8 smb3decryptionkey[SMB3_SIGN_KEY_SIZE];
-	__u8 preauth_hash[512];
+#ifdef CONFIG_CIFS_SMB311
+	__u8 preauth_sha_hash[64];
+#endif /* 3.1.1 */
 };
 
 static inline bool
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -390,6 +390,7 @@ generate_smb30signingkey(struct cifs_ses
 	return generate_smb3signingkey(ses, &triplet);
 }
 
+#ifdef CONFIG_CIFS_SMB311
 int
 generate_smb311signingkey(struct cifs_ses *ses)
 
@@ -398,25 +399,26 @@ generate_smb311signingkey(struct cifs_se
 	struct derivation *d;
 
 	d = &triplet.signing;
-	d->label.iov_base = "SMB2AESCMAC";
-	d->label.iov_len = 12;
-	d->context.iov_base = "SmbSign";
-	d->context.iov_len = 8;
+	d->label.iov_base = "SMBSigningKey";
+	d->label.iov_len = 14;
+	d->context.iov_base = ses->preauth_sha_hash;
+	d->context.iov_len = 64;
 
 	d = &triplet.encryption;
-	d->label.iov_base = "SMB2AESCCM";
-	d->label.iov_len = 11;
-	d->context.iov_base = "ServerIn ";
-	d->context.iov_len = 10;
+	d->label.iov_base = "SMBC2SCipherKey";
+	d->label.iov_len = 16;
+	d->context.iov_base = ses->preauth_sha_hash;
+	d->context.iov_len = 64;
 
 	d = &triplet.decryption;
-	d->label.iov_base = "SMB2AESCCM";
-	d->label.iov_len = 11;
-	d->context.iov_base = "ServerOut";
-	d->context.iov_len = 10;
+	d->label.iov_base = "SMBS2CCipherKey";
+	d->label.iov_len = 16;
+	d->context.iov_base = ses->preauth_sha_hash;
+	d->context.iov_len = 64;
 
 	return generate_smb3signingkey(ses, &triplet);
 }
+#endif /* 311 */
 
 int
 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)