From 166cea4dc3a4f66f020cfb9286225ecd228ab61d Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Fri, 7 Oct 2016 19:11:22 +0100 Subject: SMB2: Separate RawNTLMSSP authentication from SMB2_sess_setup We split the rawntlmssp authentication into negotiate and authencate parts. We also clean up the code and add helpers. Signed-off-by: Sachin Prabhu Signed-off-by: Steve French Reviewed-by: Pavel Shilovsky --- fs/cifs/smb2pdu.c | 361 ++++++++++++++++++++++++------------------------------ 1 file changed, 162 insertions(+), 199 deletions(-) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 386b512189b2..5ca5ea4668a1 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -803,245 +803,208 @@ SMB2_auth_kerberos(struct SMB2_sess_data *sess_data) } #endif -int -SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses, - const struct nls_table *nls_cp) +static void +SMB2_sess_auth_rawntlmssp_authenticate(struct SMB2_sess_data *sess_data); + +static void +SMB2_sess_auth_rawntlmssp_negotiate(struct SMB2_sess_data *sess_data) { - struct smb2_sess_setup_req *req; + int rc; + struct cifs_ses *ses = sess_data->ses; struct smb2_sess_setup_rsp *rsp = NULL; - struct kvec iov[2]; - int rc = 0; - int resp_buftype = CIFS_NO_BUFFER; - __le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */ - struct TCP_Server_Info *server = ses->server; - u16 blob_length = 0; - char *security_blob = NULL; - unsigned char *ntlmssp_blob = NULL; + char *ntlmssp_blob = NULL; bool use_spnego = false; /* else use raw ntlmssp */ - u64 previous_session = ses->Suid; - struct SMB2_sess_data *sess_data; - - cifs_dbg(FYI, "Session Setup\n"); - - if (!server) { - WARN(1, "%s: server is NULL!\n", __func__); - return -EIO; - } - - sess_data = kzalloc(sizeof(struct SMB2_sess_data), GFP_KERNEL); - if (!sess_data) - return -ENOMEM; - sess_data->xid = xid; - sess_data->ses = ses; - sess_data->buf0_type = CIFS_NO_BUFFER; - sess_data->nls_cp = (struct nls_table *) nls_cp; - sess_data->previous_session = ses->Suid; - - if (ses->sectype == Kerberos) { - SMB2_auth_kerberos(sess_data); - goto out; - } - - /* - * If we are here due to reconnect, free per-smb session key - * in case signing was required. - */ - kfree(ses->auth_key.response); - ses->auth_key.response = NULL; + u16 blob_length = 0; /* * If memory allocation is successful, caller of this function * frees it. */ ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL); - if (!ses->ntlmssp) - return -ENOMEM; + if (!ses->ntlmssp) { + rc = -ENOMEM; + goto out_err; + } ses->ntlmssp->sesskey_per_smbsess = true; - /* FIXME: allow for other auth types besides NTLMSSP (e.g. krb5) */ - if (ses->sectype != Kerberos && ses->sectype != RawNTLMSSP) - ses->sectype = RawNTLMSSP; - -ssetup_ntlmssp_authenticate: - if (phase == NtLmChallenge) - phase = NtLmAuthenticate; /* if ntlmssp, now final phase */ - - rc = small_smb2_init(SMB2_SESSION_SETUP, NULL, (void **) &req); + rc = SMB2_sess_alloc_buffer(sess_data); if (rc) - return rc; - - req->hdr.SessionId = 0; /* First session, not a reauthenticate */ + goto out_err; - /* if reconnect, we need to send previous sess id, otherwise it is 0 */ - req->PreviousSessionId = previous_session; + ntlmssp_blob = kmalloc(sizeof(struct _NEGOTIATE_MESSAGE), + GFP_KERNEL); + if (ntlmssp_blob == NULL) { + rc = -ENOMEM; + goto out; + } - req->Flags = 0; /* MBZ */ - /* to enable echos and oplocks */ - req->hdr.CreditRequest = cpu_to_le16(3); + build_ntlmssp_negotiate_blob(ntlmssp_blob, ses); + if (use_spnego) { + /* BB eventually need to add this */ + cifs_dbg(VFS, "spnego not supported for SMB2 yet\n"); + rc = -EOPNOTSUPP; + goto out; + } else { + blob_length = sizeof(struct _NEGOTIATE_MESSAGE); + /* with raw NTLMSSP we don't encapsulate in SPNEGO */ + } + sess_data->iov[1].iov_base = ntlmssp_blob; + sess_data->iov[1].iov_len = blob_length; - /* only one of SMB2 signing flags may be set in SMB2 request */ - if (server->sign) - req->SecurityMode = SMB2_NEGOTIATE_SIGNING_REQUIRED; - else if (global_secflags & CIFSSEC_MAY_SIGN) /* one flag unlike MUST_ */ - req->SecurityMode = SMB2_NEGOTIATE_SIGNING_ENABLED; - else - req->SecurityMode = 0; + rc = SMB2_sess_sendreceive(sess_data); + rsp = (struct smb2_sess_setup_rsp *)sess_data->iov[0].iov_base; - req->Capabilities = 0; - req->Channel = 0; /* MBZ */ + /* If true, rc here is expected and not an error */ + if (sess_data->buf0_type != CIFS_NO_BUFFER && + rsp->hdr.Status == STATUS_MORE_PROCESSING_REQUIRED) + rc = 0; - 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 (rc) + goto out; - if (phase == NtLmNegotiate) { - ntlmssp_blob = kmalloc(sizeof(struct _NEGOTIATE_MESSAGE), - GFP_KERNEL); - if (ntlmssp_blob == NULL) { - rc = -ENOMEM; - goto ssetup_exit; - } - build_ntlmssp_negotiate_blob(ntlmssp_blob, ses); - if (use_spnego) { - /* blob_length = build_spnego_ntlmssp_blob( - &security_blob, - sizeof(struct _NEGOTIATE_MESSAGE), - ntlmssp_blob); */ - /* BB eventually need to add this */ - cifs_dbg(VFS, "spnego not supported for SMB2 yet\n"); - rc = -EOPNOTSUPP; - kfree(ntlmssp_blob); - goto ssetup_exit; - } else { - blob_length = sizeof(struct _NEGOTIATE_MESSAGE); - /* 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; - rc = build_ntlmssp_auth_blob(&ntlmssp_blob, &blob_length, ses, - nls_cp); - if (rc) { - cifs_dbg(FYI, "build_ntlmssp_auth_blob failed %d\n", - rc); - goto ssetup_exit; /* BB double check error handling */ - } - if (use_spnego) { - /* blob_length = build_spnego_ntlmssp_blob( - &security_blob, - blob_length, - ntlmssp_blob); */ - cifs_dbg(VFS, "spnego not supported for SMB2 yet\n"); - rc = -EOPNOTSUPP; - kfree(ntlmssp_blob); - goto ssetup_exit; - } 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"); + if (offsetof(struct smb2_sess_setup_rsp, Buffer) - 4 != + le16_to_cpu(rsp->SecurityBufferOffset)) { + cifs_dbg(VFS, "Invalid security buffer offset %d\n", + le16_to_cpu(rsp->SecurityBufferOffset)); rc = -EIO; - goto ssetup_exit; + goto out; } + rc = decode_ntlmssp_challenge(rsp->Buffer, + le16_to_cpu(rsp->SecurityBufferLength), ses); + if (rc) + goto out; - /* Testing shows that buffer offset must be at location of Buffer[0] */ - req->SecurityBufferOffset = - cpu_to_le16(sizeof(struct smb2_sess_setup_req) - - 1 /* pad */ - 4 /* rfc1001 len */); - req->SecurityBufferLength = cpu_to_le16(blob_length); + cifs_dbg(FYI, "rawntlmssp session setup challenge phase\n"); - inc_rfc1001_len(req, blob_length - 1 /* pad */); - /* BB add code to build os and lm fields */ + ses->Suid = rsp->hdr.SessionId; + ses->session_flags = le16_to_cpu(rsp->SessionFlags); + if (ses->session_flags & SMB2_SESSION_FLAG_ENCRYPT_DATA) + cifs_dbg(VFS, "SMB3 encryption not supported yet\n"); - rc = SendReceive2(xid, ses, iov, 2, &resp_buftype, - CIFS_LOG_ERROR | CIFS_NEG_OP); +out: + kfree(ntlmssp_blob); + SMB2_sess_free_buffer(sess_data); + if (!rc) { + sess_data->result = 0; + sess_data->func = SMB2_sess_auth_rawntlmssp_authenticate; + return; + } +out_err: + kfree(ses->ntlmssp); + ses->ntlmssp = NULL; + sess_data->result = rc; + sess_data->func = NULL; +} - 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) { - cifs_dbg(VFS, "Unexpected more processing error\n"); - goto ssetup_exit; - } - if (offsetof(struct smb2_sess_setup_rsp, Buffer) - 4 != - le16_to_cpu(rsp->SecurityBufferOffset)) { - cifs_dbg(VFS, "Invalid security buffer offset %d\n", - le16_to_cpu(rsp->SecurityBufferOffset)); - rc = -EIO; - goto ssetup_exit; - } +static void +SMB2_sess_auth_rawntlmssp_authenticate(struct SMB2_sess_data *sess_data) +{ + int rc; + struct cifs_ses *ses = sess_data->ses; + struct smb2_sess_setup_req *req; + struct smb2_sess_setup_rsp *rsp = NULL; + unsigned char *ntlmssp_blob = NULL; + bool use_spnego = false; /* else use raw ntlmssp */ + u16 blob_length = 0; + + rc = SMB2_sess_alloc_buffer(sess_data); + if (rc) + goto out; + + req = (struct smb2_sess_setup_req *) sess_data->iov[0].iov_base; + req->hdr.SessionId = ses->Suid; - /* NTLMSSP Negotiate sent now processing challenge (response) */ - phase = NtLmChallenge; /* process ntlmssp challenge */ - rc = 0; /* MORE_PROCESSING is not an error here but expected */ - rc = decode_ntlmssp_challenge(rsp->Buffer, - le16_to_cpu(rsp->SecurityBufferLength), ses); + rc = build_ntlmssp_auth_blob(&ntlmssp_blob, &blob_length, ses, + sess_data->nls_cp); + if (rc) { + cifs_dbg(FYI, "build_ntlmssp_auth_blob failed %d\n", rc); + goto out; } - /* - * BB eventually add code for SPNEGO decoding of NtlmChallenge blob, - * but at least the raw NTLMSSP case works. - */ - /* - * No tcon so can't do - * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]); - */ - if (rc != 0) - goto ssetup_exit; + if (use_spnego) { + /* BB eventually need to add this */ + cifs_dbg(VFS, "spnego not supported for SMB2 yet\n"); + rc = -EOPNOTSUPP; + goto out; + } + sess_data->iov[1].iov_base = ntlmssp_blob; + sess_data->iov[1].iov_len = blob_length; + + rc = SMB2_sess_sendreceive(sess_data); + if (rc) + goto out; + + rsp = (struct smb2_sess_setup_rsp *)sess_data->iov[0].iov_base; + ses->Suid = rsp->hdr.SessionId; ses->session_flags = le16_to_cpu(rsp->SessionFlags); if (ses->session_flags & SMB2_SESSION_FLAG_ENCRYPT_DATA) cifs_dbg(VFS, "SMB3 encryption not supported yet\n"); -ssetup_exit: - free_rsp_buf(resp_buftype, rsp); - /* if ntlmssp, and negotiate succeeded, proceed to authenticate phase */ - if ((phase == NtLmChallenge) && (rc == 0)) - goto ssetup_ntlmssp_authenticate; + rc = SMB2_sess_establish_session(sess_data); +out: + kfree(ntlmssp_blob); + SMB2_sess_free_buffer(sess_data); + kfree(ses->ntlmssp); + ses->ntlmssp = NULL; + sess_data->result = rc; + sess_data->func = NULL; +} - if (!rc) { - mutex_lock(&server->srv_mutex); - if (server->sign && server->ops->generate_signingkey) { - rc = server->ops->generate_signingkey(ses); - kfree(ses->auth_key.response); - ses->auth_key.response = NULL; - if (rc) { - cifs_dbg(FYI, - "SMB3 session key generation failed\n"); - mutex_unlock(&server->srv_mutex); - goto keygen_exit; - } - } - if (!server->session_estab) { - server->sequence_number = 0x2; - server->session_estab = true; - } - mutex_unlock(&server->srv_mutex); +static int +SMB2_select_sec(struct cifs_ses *ses, struct SMB2_sess_data *sess_data) +{ + if (ses->sectype != Kerberos && ses->sectype != RawNTLMSSP) + ses->sectype = RawNTLMSSP; - cifs_dbg(FYI, "SMB2/3 session established successfully\n"); - spin_lock(&GlobalMid_Lock); - ses->status = CifsGood; - ses->need_reconnect = false; - spin_unlock(&GlobalMid_Lock); + switch (ses->sectype) { + case Kerberos: + sess_data->func = SMB2_auth_kerberos; + break; + case RawNTLMSSP: + sess_data->func = SMB2_sess_auth_rawntlmssp_negotiate; + break; + default: + cifs_dbg(VFS, "secType %d not supported!\n", ses->sectype); + return -EOPNOTSUPP; } -keygen_exit: - if (!server->sign) { - kfree(ses->auth_key.response); - ses->auth_key.response = NULL; + return 0; +} + +int +SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses, + const struct nls_table *nls_cp) +{ + int rc = 0; + struct TCP_Server_Info *server = ses->server; + struct SMB2_sess_data *sess_data; + + cifs_dbg(FYI, "Session Setup\n"); + + if (!server) { + WARN(1, "%s: server is NULL!\n", __func__); + return -EIO; } - kfree(ses->ntlmssp); - return rc; -out: + sess_data = kzalloc(sizeof(struct SMB2_sess_data), GFP_KERNEL); + if (!sess_data) + return -ENOMEM; + + rc = SMB2_select_sec(ses, sess_data); + if (rc) + goto out; + sess_data->xid = xid; + sess_data->ses = ses; + sess_data->buf0_type = CIFS_NO_BUFFER; + sess_data->nls_cp = (struct nls_table *) nls_cp; + + while (sess_data->func) + sess_data->func(sess_data); + rc = sess_data->result; +out: kfree(sess_data); return rc; } -- cgit v1.2.3-58-ga151