xref: /titanic_41/usr/src/lib/libsmbfs/smb/ssp.c (revision f9ead4a57883f3ef04ef20d83cc47987d98c0687)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * Security Provider glue
29  *
30  * Modeled after SSPI for now, only because we're currently
31  * using the Microsoft sample spnego code.
32  *
33  * ToDo: Port all of this to GSS-API plugins.
34  */
35 
36 #include <errno.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <unistd.h>
40 #include <strings.h>
41 #include <netdb.h>
42 #include <libintl.h>
43 #include <xti.h>
44 #include <assert.h>
45 
46 #include <sys/types.h>
47 #include <sys/time.h>
48 #include <sys/byteorder.h>
49 #include <sys/socket.h>
50 #include <sys/fcntl.h>
51 
52 #include <netinet/in.h>
53 #include <netinet/tcp.h>
54 #include <arpa/inet.h>
55 
56 #include <netsmb/smb_lib.h>
57 #include <netsmb/mchain.h>
58 
59 #include "private.h"
60 #include "charsets.h"
61 #include "spnego.h"
62 #include "derparse.h"
63 #include "ssp.h"
64 
65 
66 /*
67  * ssp_ctx_create_client
68  *
69  * This is the first function called for SMB "extended security".
70  * Here we select a security support provider (SSP), or mechanism,
71  * and build the security context used throughout authentication.
72  *
73  * Note that we receive a "hint" in the SMB Negotiate response
74  * that contains the list of mechanisms supported by the server.
75  * We use this to help us select a mechanism.
76  *
77  * With SSPI this would call:
78  *	ssp->InitSecurityInterface()
79  *	ssp->AcquireCredentialsHandle()
80  *	ssp->InitializeSecurityContext()
81  * With GSS-API this will become:
82  *	gss_import_name(... service_principal_name)
83  *	gss_init_sec_context(), etc.
84  */
85 int
86 ssp_ctx_create_client(struct smb_ctx *ctx, struct mbdata *hint_mb)
87 {
88 	struct ssp_ctx *sp;
89 	mbuf_t *m;
90 	SPNEGO_MECH_OID oid;
91 	int indx, rc;
92 	int err = ENOTSUP; /* in case nothing matches */
93 
94 	sp = malloc(sizeof (*sp));
95 	if (sp == NULL)
96 		return (ENOMEM);
97 	bzero(sp, sizeof (*sp));
98 	ctx->ct_ssp_ctx = sp;
99 	sp->smb_ctx = ctx;
100 
101 	/*
102 	 * Parse the SPNEGO "hint" to get the server's list of
103 	 * supported mechanisms.  If the "hint" is empty,
104 	 * assume NTLMSSP.  (Or could use "raw NTLMSSP")
105 	 */
106 	m = hint_mb->mb_top;
107 	if (m == NULL)
108 		goto use_ntlm;
109 	rc = spnegoInitFromBinary((uchar_t *)m->m_data, m->m_len,
110 	    &sp->sp_hint);
111 	if (rc) {
112 		DPRINT("parse hint, rc %d", rc);
113 		goto use_ntlm;
114 	}
115 
116 	/*
117 	 * Did the server offer Kerberos?
118 	 * Either spec. OID or legacy is OK,
119 	 * but have to remember what we got.
120 	 */
121 	oid = spnego_mech_oid_NotUsed;
122 	if (0 == spnegoIsMechTypeAvailable(sp->sp_hint,
123 	    spnego_mech_oid_Kerberos_V5, &indx))
124 		oid = spnego_mech_oid_Kerberos_V5;
125 	else if (0 == spnegoIsMechTypeAvailable(sp->sp_hint,
126 	    spnego_mech_oid_Kerberos_V5_Legacy, &indx))
127 		oid = spnego_mech_oid_Kerberos_V5_Legacy;
128 	if (oid != spnego_mech_oid_NotUsed) {
129 		/*
130 		 * Yes! Server offers Kerberos.
131 		 * Try to init our krb5 mechanism.
132 		 * It will fail if the calling user
133 		 * does not have krb5 credentials.
134 		 */
135 		sp->sp_mech = oid;
136 		err = krb5ssp_init_client(sp);
137 		if (err == 0) {
138 			DPRINT("using Kerberos");
139 			return (0);
140 		}
141 		/* else fall back to NTLMSSP */
142 	}
143 
144 	/*
145 	 * Did the server offer NTLMSSP?
146 	 */
147 	if (0 == spnegoIsMechTypeAvailable(sp->sp_hint,
148 	    spnego_mech_oid_NTLMSSP, &indx)) {
149 		/*
150 		 * OK, we'll use NTLMSSP
151 		 */
152 	use_ntlm:
153 		sp->sp_mech = spnego_mech_oid_NTLMSSP;
154 		err = ntlmssp_init_client(sp);
155 		if (err == 0) {
156 			DPRINT("using NTLMSSP");
157 			return (0);
158 		}
159 	}
160 
161 	/* No supported mechanisms! */
162 	return (err);
163 }
164 
165 
166 /*
167  * ssp_ctx_destroy
168  *
169  * Dispatch to the mechanism-specific destroy.
170  */
171 void
172 ssp_ctx_destroy(struct smb_ctx *ctx)
173 {
174 	ssp_ctx_t *sp;
175 
176 	sp = ctx->ct_ssp_ctx;
177 	ctx->ct_ssp_ctx = NULL;
178 
179 	if (sp == NULL)
180 		return;
181 
182 	if (sp->sp_destroy != NULL)
183 		(sp->sp_destroy)(sp);
184 
185 	if (sp->sp_hint != NULL)
186 		spnegoFreeData(sp->sp_hint);
187 
188 	free(sp);
189 }
190 
191 
192 /*
193  * ssp_ctx_next_token
194  *
195  * This is the function called to generate the next token to send,
196  * given a token just received, using the selected back-end method.
197  * The back-end method is called a security service provider (SSP).
198  *
199  * This is also called to generate the first token to send
200  * (when called with caller_in == NULL) and to handle the last
201  * token received (when called with caller_out == NULL).
202  * See caller: smb_ssnsetup_spnego
203  *
204  * Note that if the back-end SSP "next token" function ever
205  * returns an error, the conversation ends, and there are
206  * no further calls to this function for this context.
207  *
208  * General outline of this funcion:
209  *	if (caller_in)
210  *		Unwrap caller_in spnego blob,
211  *		store payload in body_in
212  *	Call back-end SSP "next token" method (body_in, body_out)
213  *	if (caller_out)
214  *		Wrap returned body_out in spnego,
215  *		store in caller_out
216  *
217  * With SSPI this would call:
218  *	ssp->InitializeSecurityContext()
219  * With GSS-API this will become:
220  *	gss_init_sec_context()
221  */
222 int
223 ssp_ctx_next_token(struct smb_ctx *ctx,
224 	struct mbdata *caller_in,
225 	struct mbdata *caller_out)
226 {
227 	struct mbdata body_in, body_out;
228 	SPNEGO_TOKEN_HANDLE stok_in, stok_out;
229 	SPNEGO_NEGRESULT result;
230 	ssp_ctx_t *sp;
231 	struct mbuf *m;
232 	ulong_t toklen;
233 	int err, rc;
234 
235 	bzero(&body_in, sizeof (body_in));
236 	bzero(&body_out, sizeof (body_out));
237 	stok_out = stok_in = NULL;
238 	sp = ctx->ct_ssp_ctx;
239 
240 	/*
241 	 * If we have an spnego input token, parse it,
242 	 * extract the payload for the back-end SSP.
243 	 */
244 	if (caller_in != NULL) {
245 
246 		/*
247 		 * Let the spnego code parse it.
248 		 */
249 		m = caller_in->mb_top;
250 		rc = spnegoInitFromBinary((uchar_t *)m->m_data,
251 		    m->m_len, &stok_in);
252 		if (rc) {
253 			DPRINT("parse reply, rc %d", rc);
254 			err = EBADRPC;
255 			goto out;
256 		}
257 		/* Note: Allocated stok_in  */
258 
259 		/*
260 		 * Now get the payload.  Two calls:
261 		 * first gets the size, 2nd the data.
262 		 *
263 		 * Expect SPNEGO_E_BUFFER_TOO_SMALL here,
264 		 * but if the payload is missing, we'll
265 		 * get SPNEGO_E_ELEMENT_UNAVAILABLE.
266 		 */
267 		rc = spnegoGetMechToken(stok_in, NULL, &toklen);
268 		switch (rc) {
269 		case SPNEGO_E_ELEMENT_UNAVAILABLE:
270 			toklen = 0;
271 			break;
272 		case SPNEGO_E_BUFFER_TOO_SMALL:
273 			/* have toklen */
274 			break;
275 		default:
276 			DPRINT("GetMechTok1, rc %d", rc);
277 			err = EBADRPC;
278 			goto out;
279 		}
280 		err = mb_init(&body_in, (size_t)toklen);
281 		if (err)
282 			goto out;
283 		m = body_in.mb_top;
284 		if (toklen > 0) {
285 			rc = spnegoGetMechToken(stok_in,
286 			    (uchar_t *)m->m_data, &toklen);
287 			if (rc) {
288 				DPRINT("GetMechTok2, rc %d", rc);
289 				err = EBADRPC;
290 				goto out;
291 			}
292 			body_in.mb_count = m->m_len = (size_t)toklen;
293 		}
294 	}
295 
296 	/*
297 	 * Call the back-end security provider (SSP) to
298 	 * handle the received token (if present) and
299 	 * generate an output token (if requested).
300 	 */
301 	err = sp->sp_nexttok(sp,
302 	    caller_in ? &body_in : NULL,
303 	    caller_out ? &body_out : NULL);
304 	if (err)
305 		goto out;
306 
307 	/*
308 	 * Wrap the outgoing body if requested,
309 	 * either negTokenInit on first call, or
310 	 * negTokenTarg on subsequent calls.
311 	 */
312 	if (caller_out != NULL) {
313 		m = body_out.mb_top;
314 
315 		if (caller_in == NULL) {
316 			/*
317 			 * This is the first call, so create a
318 			 * negTokenInit.
319 			 */
320 			rc = spnegoCreateNegTokenInit(
321 			    sp->sp_mech, 0,
322 			    (uchar_t *)m->m_data, m->m_len,
323 			    NULL, 0, &stok_out);
324 			/* Note: allocated stok_out */
325 		} else {
326 			/*
327 			 * Note: must pass spnego_mech_oid_NotUsed,
328 			 * instead of sp->sp_mech so that the spnego
329 			 * code will not marshal a mech OID list.
330 			 * The mechanism is determined at this point,
331 			 * and some servers won't parse an unexpected
332 			 * mech. OID list in a negTokenTarg
333 			 */
334 			rc = spnegoCreateNegTokenTarg(
335 			    spnego_mech_oid_NotUsed,
336 			    spnego_negresult_NotUsed,
337 			    (uchar_t *)m->m_data, m->m_len,
338 			    NULL, 0, &stok_out);
339 			/* Note: allocated stok_out */
340 		}
341 		if (rc) {
342 			DPRINT("CreateNegTokenX, rc 0x%x", rc);
343 			err = EBADRPC;
344 			goto out;
345 		}
346 
347 		/*
348 		 * Copy binary from stok_out to caller_out
349 		 * Two calls: get the size, get the data.
350 		 */
351 		rc = spnegoTokenGetBinary(stok_out, NULL, &toklen);
352 		if (rc != SPNEGO_E_BUFFER_TOO_SMALL) {
353 			DPRINT("GetBinary1, rc 0x%x", rc);
354 			err = EBADRPC;
355 			goto out;
356 		}
357 		err = mb_init(caller_out, (size_t)toklen);
358 		if (err)
359 			goto out;
360 		m = caller_out->mb_top;
361 		rc = spnegoTokenGetBinary(stok_out,
362 		    (uchar_t *)m->m_data, &toklen);
363 		if (rc) {
364 			DPRINT("GetBinary2, rc 0x%x", rc);
365 			err = EBADRPC;
366 			goto out;
367 		}
368 		caller_out->mb_count = m->m_len = (size_t)toklen;
369 	} else {
370 		/*
371 		 * caller_out == NULL, so this is the "final" call.
372 		 * Get final SPNEGO result from the INPUT token.
373 		 */
374 		rc = spnegoGetNegotiationResult(stok_in, &result);
375 		if (rc) {
376 			DPRINT("rc 0x%x", rc);
377 			err = EBADRPC;
378 			goto out;
379 		}
380 		DPRINT("spnego result: 0x%x", result);
381 		if (result != spnego_negresult_success) {
382 			err = EAUTH;
383 			goto out;
384 		}
385 	}
386 	err = 0;
387 
388 out:
389 	mb_done(&body_in);
390 	mb_done(&body_out);
391 	spnegoFreeData(stok_in);
392 	spnegoFreeData(stok_out);
393 
394 	return (err);
395 }
396