From ceb1b0b9b4d1089e9f2731a314689ae17784c861 Mon Sep 17 00:00:00 2001 From: Steve French Date: Thu, 24 Sep 2015 00:52:37 -0500 Subject: [PATCH] [SMB3] Fix sec=krb5 on smb3 mounts Kerberos, which is very important for security, was only enabled for CIFS not SMB2/SMB3 mounts (e.g. vers=3.0) Patch based on the information detailed in http://thread.gmane.org/gmane.linux.kernel.cifs/10081/focus=10307 to enable Kerberized SMB2/SMB3 a) SMB2_negotiate: enable/use decode_negTokenInit in SMB2_negotiate b) SMB2_sess_setup: handle Kerberos sectype and replicate Kerberos SMB1 processing done in sess_auth_kerberos Signed-off-by: Noel Power Signed-off-by: Jim McDonough CC: Stable Signed-off-by: Steve French --- fs/cifs/smb2pdu.c | 76 ++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 61 insertions(+), 15 deletions(-) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 070fb2a..e543431 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -46,6 +46,7 @@ #include "smb2status.h" #include "smb2glob.h" #include "cifspdu.h" +#include "cifs_spnego.h" /* * The following table defines the expected "StructureSize" of SMB2 requests @@ -486,19 +487,15 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses) cifs_dbg(FYI, "missing security blob on negprot\n"); rc = cifs_enable_signing(server, ses->sign); -#ifdef CONFIG_SMB2_ASN1 /* BB REMOVEME when updated asn1.c ready */ if (rc) goto neg_exit; - if (blob_length) + if (blob_length) { rc = decode_negTokenInit(security_blob, blob_length, server); - if (rc == 1) - rc = 0; - else if (rc == 0) { - rc = -EIO; - goto neg_exit; + if (rc == 1) + rc = 0; + else if (rc == 0) + rc = -EIO; } -#endif - neg_exit: free_rsp_buf(resp_buftype, rsp); return rc; @@ -592,7 +589,8 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses, __le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */ struct TCP_Server_Info *server = ses->server; u16 blob_length = 0; - char *security_blob; + struct key *spnego_key = NULL; + char *security_blob = NULL; char *ntlmssp_blob = NULL; bool use_spnego = false; /* else use raw ntlmssp */ @@ -620,7 +618,8 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses, ses->ntlmssp->sesskey_per_smbsess = true; /* FIXME: allow for other auth types besides NTLMSSP (e.g. krb5) */ - ses->sectype = RawNTLMSSP; + if (ses->sectype != Kerberos && ses->sectype != RawNTLMSSP) + ses->sectype = RawNTLMSSP; ssetup_ntlmssp_authenticate: if (phase == NtLmChallenge) @@ -649,7 +648,48 @@ ssetup_ntlmssp_authenticate: iov[0].iov_base = (char *)req; /* 4 for rfc1002 length field and 1 for pad */ iov[0].iov_len = get_rfc1002_length(req) + 4 - 1; - if (phase == NtLmNegotiate) { + + if (ses->sectype == Kerberos) { +#ifdef CONFIG_CIFS_UPCALL + struct cifs_spnego_msg *msg; + + spnego_key = cifs_get_spnego_key(ses); + if (IS_ERR(spnego_key)) { + rc = PTR_ERR(spnego_key); + spnego_key = NULL; + goto ssetup_exit; + } + + msg = spnego_key->payload.data; + /* + * check version field to make sure that cifs.upcall is + * sending us a response in an expected form + */ + if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) { + cifs_dbg(VFS, + "bad cifs.upcall version. Expected %d got %d", + CIFS_SPNEGO_UPCALL_VERSION, msg->version); + rc = -EKEYREJECTED; + goto ssetup_exit; + } + ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len, + GFP_KERNEL); + if (!ses->auth_key.response) { + cifs_dbg(VFS, + "Kerberos can't allocate (%u bytes) memory", + msg->sesskey_len); + rc = -ENOMEM; + goto ssetup_exit; + } + ses->auth_key.len = msg->sesskey_len; + blob_length = msg->secblob_len; + iov[1].iov_base = msg->data + msg->sesskey_len; + iov[1].iov_len = blob_length; +#else + rc = -EOPNOTSUPP; + goto ssetup_exit; +#endif /* CONFIG_CIFS_UPCALL */ + } else if (phase == NtLmNegotiate) { /* if not krb5 must be ntlmssp */ ntlmssp_blob = kmalloc(sizeof(struct _NEGOTIATE_MESSAGE), GFP_KERNEL); if (ntlmssp_blob == NULL) { @@ -672,6 +712,8 @@ ssetup_ntlmssp_authenticate: /* with raw NTLMSSP we don't encapsulate in SPNEGO */ security_blob = ntlmssp_blob; } + iov[1].iov_base = security_blob; + iov[1].iov_len = blob_length; } else if (phase == NtLmAuthenticate) { req->hdr.SessionId = ses->Suid; ntlmssp_blob = kzalloc(sizeof(struct _NEGOTIATE_MESSAGE) + 500, @@ -699,6 +741,8 @@ ssetup_ntlmssp_authenticate: } else { security_blob = ntlmssp_blob; } + iov[1].iov_base = security_blob; + iov[1].iov_len = blob_length; } else { cifs_dbg(VFS, "illegal ntlmssp phase\n"); rc = -EIO; @@ -710,8 +754,6 @@ ssetup_ntlmssp_authenticate: cpu_to_le16(sizeof(struct smb2_sess_setup_req) - 1 /* pad */ - 4 /* rfc1001 len */); req->SecurityBufferLength = cpu_to_le16(blob_length); - iov[1].iov_base = security_blob; - iov[1].iov_len = blob_length; inc_rfc1001_len(req, blob_length - 1 /* pad */); @@ -722,6 +764,7 @@ ssetup_ntlmssp_authenticate: kfree(security_blob); rsp = (struct smb2_sess_setup_rsp *)iov[0].iov_base; + ses->Suid = rsp->hdr.SessionId; if (resp_buftype != CIFS_NO_BUFFER && rsp->hdr.Status == STATUS_MORE_PROCESSING_REQUIRED) { if (phase != NtLmNegotiate) { @@ -739,7 +782,6 @@ ssetup_ntlmssp_authenticate: /* NTLMSSP Negotiate sent now processing challenge (response) */ phase = NtLmChallenge; /* process ntlmssp challenge */ rc = 0; /* MORE_PROCESSING is not an error here but expected */ - ses->Suid = rsp->hdr.SessionId; rc = decode_ntlmssp_challenge(rsp->Buffer, le16_to_cpu(rsp->SecurityBufferLength), ses); } @@ -796,6 +838,10 @@ keygen_exit: kfree(ses->auth_key.response); ses->auth_key.response = NULL; } + if (spnego_key) { + key_invalidate(spnego_key); + key_put(spnego_key); + } kfree(ses->ntlmssp); return rc; -- 2.7.4