xref: /freebsd/crypto/krb5/src/lib/gssapi/mechglue/g_imp_name.c (revision f1c4c3daccbaf3820f0e2224de53df12fc952fcc)
1 /* #pragma ident	"@(#)g_imp_name.c	1.26	04/02/23 SMI" */
2 
3 /*
4  * Copyright 1996 by Sun Microsystems, Inc.
5  *
6  * Permission to use, copy, modify, distribute, and sell this software
7  * and its documentation for any purpose is hereby granted without fee,
8  * provided that the above copyright notice appears in all copies and
9  * that both that copyright notice and this permission notice appear in
10  * supporting documentation, and that the name of Sun Microsystems not be used
11  * in advertising or publicity pertaining to distribution of the software
12  * without specific, written prior permission. Sun Microsystems makes no
13  * representations about the suitability of this software for any
14  * purpose.  It is provided "as is" without express or implied warranty.
15  *
16  * SUN MICROSYSTEMS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
17  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
18  * EVENT SHALL SUN MICROSYSTEMS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
19  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
20  * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
21  * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
22  * PERFORMANCE OF THIS SOFTWARE.
23  */
24 
25 /*
26  *  glue routine gss_import_name
27  *
28  */
29 
30 #include "mglueP.h"
31 #include "k5-der.h"
32 #include <stdio.h>
33 #ifdef HAVE_STDLIB_H
34 #include <stdlib.h>
35 #endif
36 #include <string.h>
37 #include <errno.h>
38 
39 /* local function to import GSS_C_EXPORT_NAME names */
40 static OM_uint32 importExportName(OM_uint32 *, gss_union_name_t, gss_OID);
41 
42 static OM_uint32
val_imp_name_args(OM_uint32 * minor_status,gss_buffer_t input_name_buffer,gss_OID input_name_type,gss_name_t * output_name)43 val_imp_name_args(
44     OM_uint32 *minor_status,
45     gss_buffer_t input_name_buffer,
46     gss_OID input_name_type,
47     gss_name_t *output_name)
48 {
49 
50     /* Initialize outputs. */
51 
52     if (minor_status != NULL)
53 	*minor_status = 0;
54 
55     if (output_name != NULL)
56 	*output_name = GSS_C_NO_NAME;
57 
58     /* Validate arguments. */
59 
60     if (minor_status == NULL)
61 	return (GSS_S_CALL_INACCESSIBLE_WRITE);
62 
63     if (output_name == NULL)
64 	return (GSS_S_CALL_INACCESSIBLE_WRITE);
65 
66     if (input_name_buffer == GSS_C_NO_BUFFER)
67 	return (GSS_S_CALL_INACCESSIBLE_READ | GSS_S_BAD_NAME);
68 
69     if (input_name_type == GSS_C_NO_OID ||
70 	!g_OID_equal(input_name_type, GSS_C_NT_ANONYMOUS)) {
71 	if (input_name_buffer->length == 0)
72 	    return (GSS_S_BAD_NAME);
73 
74 	if (input_name_buffer->value == NULL)
75 	    return (GSS_S_CALL_INACCESSIBLE_READ | GSS_S_BAD_NAME);
76     }
77 
78     return (GSS_S_COMPLETE);
79 }
80 
81 static gss_buffer_desc emptyNameBuffer;
82 
83 OM_uint32 KRB5_CALLCONV
gss_import_name(OM_uint32 * minor_status,gss_buffer_t input_name_buffer,gss_OID input_name_type,gss_name_t * output_name)84 gss_import_name(OM_uint32 * minor_status, gss_buffer_t input_name_buffer,
85 		gss_OID input_name_type, gss_name_t * output_name)
86 {
87     gss_union_name_t	union_name;
88     OM_uint32		tmp, major_status = GSS_S_FAILURE;
89 
90     if (input_name_buffer == GSS_C_NO_BUFFER)
91 	input_name_buffer = &emptyNameBuffer;
92 
93     major_status = val_imp_name_args(minor_status,
94 				     input_name_buffer, input_name_type,
95 				     output_name);
96     if (major_status != GSS_S_COMPLETE)
97 	return (major_status);
98 
99     /*
100      * First create the union name struct that will hold the external
101      * name and the name type.
102      */
103     union_name = (gss_union_name_t) malloc (sizeof(gss_union_name_desc));
104     if (!union_name)
105 	return (GSS_S_FAILURE);
106 
107     union_name->loopback = 0;
108     union_name->mech_type = 0;
109     union_name->mech_name = 0;
110     union_name->name_type = 0;
111     union_name->external_name = 0;
112 
113     /*
114      * All we do here is record the external name and name_type.
115      * When the name is actually used, the underlying gss_import_name()
116      * is called for the appropriate mechanism.  The exception to this
117      * rule is when the name of GSS_C_NT_EXPORT_NAME type.  If that is
118      * the case, then we make it MN in this call.
119      */
120     major_status = gssint_create_copy_buffer(input_name_buffer,
121 					    &union_name->external_name, 0);
122     if (major_status != GSS_S_COMPLETE) {
123 	free(union_name);
124 	return (major_status);
125     }
126 
127     if (input_name_type != GSS_C_NULL_OID) {
128 	major_status = generic_gss_copy_oid(minor_status,
129 					    input_name_type,
130 					    &union_name->name_type);
131 	if (major_status != GSS_S_COMPLETE) {
132 	    map_errcode(minor_status);
133 	    goto allocation_failure;
134 	}
135     }
136 
137     /*
138      * In MIT Distribution the mechanism is determined from the nametype;
139      * This is not a good idea - first mechanism that supports a given
140      * name type is picked up; later on the caller can request a
141      * different mechanism. So we don't determine the mechanism here. Now
142      * the user level and kernel level import_name routine looks similar
143      * except the kernel routine makes a copy of the nametype structure. We
144      * do however make this an MN for names of GSS_C_NT_EXPORT_NAME type.
145      */
146     if (input_name_type != GSS_C_NULL_OID &&
147 	(g_OID_equal(input_name_type, GSS_C_NT_EXPORT_NAME) ||
148 	 g_OID_equal(input_name_type, GSS_C_NT_COMPOSITE_EXPORT))) {
149 	major_status = importExportName(minor_status, union_name, input_name_type);
150 	if (major_status != GSS_S_COMPLETE)
151 	    goto allocation_failure;
152     }
153 
154     union_name->loopback = union_name;
155     *output_name = (gss_name_t)union_name;
156     return (GSS_S_COMPLETE);
157 
158 allocation_failure:
159     if (union_name) {
160 	if (union_name->external_name) {
161 	    if (union_name->external_name->value)
162 		free(union_name->external_name->value);
163 	    free(union_name->external_name);
164 	}
165 	if (union_name->name_type)
166 	    generic_gss_release_oid(&tmp, &union_name->name_type);
167 	if (union_name->mech_name)
168 	    gssint_release_internal_name(minor_status, union_name->mech_type,
169 					&union_name->mech_name);
170 	if (union_name->mech_type)
171 	    generic_gss_release_oid(&tmp, &union_name->mech_type);
172 	free(union_name);
173     }
174     return (major_status);
175 }
176 
177 static OM_uint32
importExportName(OM_uint32 * minor,gss_union_name_t unionName,gss_OID inputNameType)178 importExportName(OM_uint32 *minor, gss_union_name_t unionName,
179 		 gss_OID inputNameType)
180 {
181     gss_OID_desc mechOid;
182     gss_buffer_desc expName;
183     gss_mechanism mech;
184     OM_uint32 major, mechOidLen, nameLen;
185     uint8_t b2;
186     const uint8_t *name;
187     struct k5input in, oid, old_format;
188 
189     expName.value = unionName->external_name->value;
190     expName.length = unionName->external_name->length;
191     k5_input_init(&in, expName.value, expName.length);
192 
193     if (k5_input_get_byte(&in) != 0x04)
194 	return (GSS_S_DEFECTIVE_TOKEN);
195     b2 = k5_input_get_byte(&in);
196     if (b2 != 0x01 && b2 != 0x02) /* allow composite names */
197 	return (GSS_S_DEFECTIVE_TOKEN);
198 
199     mechOidLen = k5_input_get_uint16_be(&in);
200 
201     if (!k5_der_get_value(&in, 0x06, &oid))
202 	return (GSS_S_DEFECTIVE_TOKEN);
203     /* Verify that mechOidLen is consistent with the DER OID length. */
204     if (mechOidLen != k5_der_value_len(oid.len))
205 	return (GSS_S_DEFECTIVE_TOKEN);
206     mechOid.length = oid.len;
207     mechOid.elements = (uint8_t *)oid.ptr;
208     if ((mech = gssint_get_mechanism(&mechOid)) == NULL)
209 	return (GSS_S_BAD_MECH);
210 
211     if (mech->gssspi_import_name_by_mech == NULL &&
212 	mech->gss_import_name == NULL)
213 	return (GSS_S_UNAVAILABLE);
214 
215     /*
216      * we must now determine if we should unwrap the name ourselves
217      * or make the mechanism do it - we should only unwrap it
218      * if we create it; so if mech->gss_export_name == NULL, we must
219      * have created it.
220      */
221     if (mech->gss_export_name) {
222 	if (mech->gssspi_import_name_by_mech) {
223 	    major = mech->gssspi_import_name_by_mech(minor, &mechOid, &expName,
224 						     inputNameType,
225 						     &unionName->mech_name);
226 	} else {
227 	    major = mech->gss_import_name(minor, &expName, inputNameType,
228 					  &unionName->mech_name);
229 	}
230 	if (major != GSS_S_COMPLETE)
231 	    map_error(minor, mech);
232 	else {
233 	    major = generic_gss_copy_oid(minor, &mechOid,
234 					 &unionName->mech_type);
235 	    if (major != GSS_S_COMPLETE)
236 		map_errcode(minor);
237 	}
238 	return (major);
239     }
240     /*
241      * we must have exported the name - so we now need to reconstruct it
242      * and call the mechanism to create it
243      *
244      * WARNING:	Older versions of gssint_export_internal_name() did
245      *		not export names correctly, but now it does.  In
246      *		order to stay compatible with existing exported
247      *		names we must support names exported the broken
248      *		way.
249      *
250      * Specifically, gssint_export_internal_name() used to include
251      * the name type OID in the encoding of the exported MN.
252      * Additionally, the Kerberos V mech used to make display names
253      * that included a null terminator which was counted in the
254      * display name gss_buffer_desc.
255      */
256 
257     /* next 4 bytes in the name are the name length */
258     nameLen = k5_input_get_uint32_be(&in);
259     name = k5_input_get_bytes(&in, nameLen);
260     if (name == NULL)
261 	return (GSS_S_DEFECTIVE_TOKEN);
262 
263     /*
264      * We detect broken exported names here: they always start with
265      * a two-octet network-byte order OID length, which is always
266      * less than 256 bytes, so the first octet of the length is
267      * always '\0', which is not allowed in GSS-API display names
268      * (or never occurs in them anyways).  Of course, the OID
269      * shouldn't be there, but it is.  After the OID (sans DER tag
270      * and length) there's the name itself, though null-terminated;
271      * this null terminator should also not be there, but it is.
272      */
273     if (nameLen > 0 && *name == '\0') {
274 	OM_uint32 nameTypeLen;
275 
276 	/* Skip the name type. */
277 	k5_input_init(&old_format, name, nameLen);
278 	nameTypeLen = k5_input_get_uint16_be(&old_format);
279 	if (k5_input_get_bytes(&old_format, nameTypeLen) == NULL)
280 	    return (GSS_S_DEFECTIVE_TOKEN);
281 	/* Remove a null terminator if one is present. */
282 	if (old_format.len > 0 && old_format.ptr[old_format.len - 1] == 0)
283 	    old_format.len--;
284 	name = old_format.ptr;
285 	nameLen = old_format.len;
286     }
287 
288     /*
289      * Can a name be null?  Let the mech decide.
290      *
291      * NOTE: We use GSS_C_NULL_OID as the name type when importing
292      *	 the unwrapped name.  Presumably the exported name had,
293      *	 prior to being exported been obtained in such a way
294      *	 that it has been properly perpared ("canonicalized," in
295      *	 GSS-API terms) according to some name type; we cannot
296      *	 tell what that name type was now, but the name should
297      *	 need no further preparation other than the lowest
298      *	 common denominator afforded by the mech to names
299      *	 imported with GSS_C_NULL_OID.  For the Kerberos V mech
300      *	 this means doing less busywork too (particularly once
301      *	 IDN is thrown in with Kerberos V extensions).
302      */
303     expName.length = nameLen;
304     expName.value = nameLen ? (uint8_t *)name : NULL;
305     if (mech->gssspi_import_name_by_mech) {
306 	major = mech->gssspi_import_name_by_mech(minor, &mechOid, &expName,
307 						 GSS_C_NULL_OID,
308 						 &unionName->mech_name);
309     } else {
310 	major = mech->gss_import_name(minor, &expName,
311 				      GSS_C_NULL_OID, &unionName->mech_name);
312     }
313     if (major != GSS_S_COMPLETE) {
314 	map_error(minor, mech);
315 	return (major);
316     }
317 
318     major = generic_gss_copy_oid(minor, &mechOid, &unionName->mech_type);
319     if (major != GSS_S_COMPLETE) {
320 	map_errcode(minor);
321     }
322     return major;
323 } /* importExportName */
324