Commit 166cea4d authored by Sachin Prabhu's avatar Sachin Prabhu Committed by Steve French

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: default avatarSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
Reviewed-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
parent 3baf1a7b
......@@ -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;
}
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment