xref: /illumos-gate/usr/src/cmd/gss/gsscred/gsscred_utils.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  *
29  *  gsscred utility
30  *  Manages mapping between a security principal name and unix uid
31  */
32 
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <errno.h>
37 #include <ctype.h>
38 #include "gsscred.h"
39 
40 /* From g_glue.c */
41 
42 extern int
43 get_der_length(unsigned char **, unsigned int, unsigned int *);
44 
45 extern unsigned int
46 der_length_size(unsigned int);
47 
48 extern int
49 put_der_length(unsigned int, unsigned char **, unsigned int);
50 
51 
52 
53 /*
54  * GSS export name constants
55  */
56 static const char *expNameTokId = "\x04\x01";
57 static const int expNameTokIdLen = 2;
58 static const int mechOidLenLen = 2;
59 static const int mechOidTagLen = 1;
60 
61 
62 /*
63  * Internal utility routines.
64  */
65 
66 /*
67  * gsscred_read_config_file
68  *
69  * function to read the optional gsscred configuration file
70  * which specifies which backend to use to store the gsscred
71  * table.
72  *
73  * we now only support flat files (btw, this file for backend is Obsoleted
74  * by PSARC)
75  */
76 int
77 gsscred_read_config_file(void)
78 {
79 	return (GSSCRED_FLAT_FILE);
80 } /* gsscred_read_config_file */
81 
82 
83 /*
84  * gsscred_MakeName
85  *
86  * construct a principal name in the GSS_C_NT_EXPORT_NAME format.
87  */
88 int gsscred_MakeName(const gss_OID mechOid, const char *name,
89 		const char *nameOidStr, gss_buffer_t nameOut)
90 {
91 	gss_OID nameOid;
92 	gss_name_t intName;
93 	OM_uint32 minor, major;
94 	gss_buffer_desc aName = GSS_C_EMPTY_BUFFER, oidStr;
95 
96 	nameOut->length = 0;
97 	nameOut->value = NULL;
98 
99 	/* we need to import the name, then canonicalize it, then export it */
100 	if (nameOidStr == NULL)
101 		nameOid = (gss_OID)GSS_C_NT_USER_NAME;
102 	else {
103 		oidStr.length = strlen(nameOidStr);
104 		oidStr.value = (void *)nameOidStr;
105 		if (gss_str_to_oid(&minor, &oidStr, &nameOid) !=
106 			GSS_S_COMPLETE) {
107 			(void) fprintf(stderr,
108 				gettext("\nInvalid name oid supplied [%s].\n"),
109 				nameOidStr);
110 			return (0);
111 		}
112 	}
113 
114 	/* first import the name */
115 	aName.length = strlen(name);
116 	aName.value = (void*)name;
117 	major = gss_import_name(&minor, &aName, nameOid, &intName);
118 	if (nameOidStr != NULL) {
119 		free(nameOid->elements);
120 		free(nameOid);
121 	}
122 
123 	if (major != GSS_S_COMPLETE) {
124 		(void) fprintf(stderr,
125 			gettext("\nInternal error importing name [%s].\n"),
126 			name);
127 		return (0);
128 	}
129 
130 	/* now canonicalize the name */
131 	if (gss_canonicalize_name(&minor, intName, mechOid, NULL)
132 	    != GSS_S_COMPLETE) {
133 		(void) fprintf(stderr,
134 			gettext("\nInternal error canonicalizing name"
135 				" [%s].\n"),
136 			name);
137 		(void) gss_release_name(&minor, &intName);
138 		return (0);
139 	}
140 
141 	/* now convert to export format */
142 	if (gss_export_name(&minor, intName, nameOut) != GSS_S_COMPLETE) {
143 		(void) fprintf(stderr,
144 			gettext("\nInternal error exporting name [%s].\n"),
145 			name);
146 		(void) gss_release_name(&minor, &intName);
147 		return (0);
148 	}
149 
150 	(void) gss_release_name(&minor, &intName);
151 	return (1);
152 } /* *******  makeName ****** */
153 
154 
155 /*
156  * Constructs a part of the GSS_NT_EXPORT_NAME
157  * Only the mechanism independent name part is created.
158  */
159 int
160 gsscred_MakeNameHeader(const gss_OID mechOid, gss_buffer_t outNameHdr)
161 {
162 	unsigned char *buf = NULL;
163 	int mechOidDERLength, mechOidLength;
164 
165 	/* determine the length of buffer needed */
166 	mechOidDERLength = der_length_size(mechOid->length);
167 	outNameHdr->length = mechOidLenLen + mechOidTagLen +
168 		mechOidDERLength + expNameTokIdLen + mechOid->length;
169 	if ((outNameHdr->value = (void*)malloc(outNameHdr->length)) == NULL) {
170 		outNameHdr->length = 0;
171 		return (0);
172 	}
173 
174 	/* start by putting the token id */
175 	buf = (unsigned char *) outNameHdr->value;
176 	(void) memset(outNameHdr->value, '\0', outNameHdr->length);
177 	(void) memcpy(buf, expNameTokId, expNameTokIdLen);
178 	buf += expNameTokIdLen;
179 
180 	/*
181 	 * next 2 bytes contain the mech oid length (includes
182 	 * DER encoding)
183 	 */
184 	mechOidLength =  mechOidTagLen + mechOidDERLength +
185 				mechOid->length;
186 
187 	*buf++ = (mechOidLength & 0xFF00) >> 8;
188 	*buf++ = (mechOidLength & 0x00FF);
189 	*buf++ = 0x06;
190 	if (put_der_length(mechOid->length, &buf,
191 		mechOidDERLength) != 0) {
192 		/* free the buffer */
193 		free(outNameHdr->value);
194 		return (0);
195 	}
196 
197 	/* now add the mechanism oid */
198 	(void) memcpy(buf, mechOid->elements, mechOid->length);
199 
200 	/* we stop here because the rest is mechanism specific */
201 	return (1);
202 } /* gsscred_MakeNameHeader */
203 
204 
205 /*
206  * Converts the supplied string to HEX.
207  * The passed in buffer must be twice as long as the input buffer.
208  * Long form is used (i.e. '\0' will become '00').  This is needed
209  * to enable proper re-parsing of names.
210  */
211 int
212 gsscred_AsHex(gss_buffer_t dataIn, gss_buffer_t dataOut)
213 {
214 	int i;
215 	char *out, *in;
216 	unsigned int tmp;
217 
218 	if (dataOut->length < ((dataIn->length *2) + 1))
219 		return (0);
220 
221 	out = (char *)dataOut->value;
222 	in = (char *)dataIn->value;
223 	dataOut->length = 0;
224 
225 	for (i = 0; i < dataIn->length; i++) {
226 		tmp = (unsigned int)(*in++)&0xff;
227 		(void) sprintf(out, "%02X", tmp);
228 		out++;
229 		out++;
230 	}
231 	dataOut->length = out - (char *)dataOut->value;
232 	*out = '\0';
233 
234 	return (1);
235 } /* ******* gsscred_AsHex ******* */
236 
237 
238 /*
239  * GSS entry point for retrieving user uid mappings.
240  * The name buffer contains a principal name in exported format.
241  */
242 int
243 gss_getGssCredEntry(const gss_buffer_t expName, uid_t *uid)
244 {
245 	int tableSource;
246 	unsigned char *buf;
247 	gss_buffer_desc mechOidDesc = GSS_C_EMPTY_BUFFER,
248 		mechHexOidDesc = GSS_C_EMPTY_BUFFER,
249 		expNameHexDesc = GSS_C_EMPTY_BUFFER;
250 	char oidHexBuf[256], expNameHexBuf[1024];
251 	unsigned int dummy;
252 	int len;
253 
254 	tableSource = gsscred_read_config_file();
255 
256 	/*
257 	 * for xfn (ldap?), we must first construct, a hex mechansim oid string
258 	 */
259 	if (expName->length < (expNameTokIdLen + mechOidLenLen +
260 					mechOidTagLen))
261 	    return (0);
262 
263 	buf = (unsigned char *)expName->value;
264 	buf += expNameTokIdLen;
265 
266 	/* skip oid length - get to der */
267 	buf++;
268 	buf++;
269 
270 	/* skip oid tag */
271 	buf++;
272 
273 	/* get oid length */
274 	len = get_der_length(&buf,
275 			(expName->length - expNameTokIdLen
276 			- mechOidLenLen - mechOidTagLen), &dummy);
277 	if (len  == -1)
278 		return (0);
279 	else
280 		mechOidDesc.length = len;
281 
282 	if (expName->length <
283 		(expNameTokIdLen + mechOidLenLen + mechOidDesc.length
284 			+  dummy+ mechOidTagLen))
285 		return (0);
286 
287 	mechOidDesc.value = (void *)buf;
288 
289 	/* convert the oid buffer to hex */
290 	mechHexOidDesc.value = (void*) oidHexBuf;
291 	mechHexOidDesc.length = sizeof (oidHexBuf);
292 	if (!gsscred_AsHex(&mechOidDesc, &mechHexOidDesc))
293 		return (0);
294 
295 	/* also need to convert the name buffer into hex */
296 	expNameHexDesc.value = expNameHexBuf;
297 	expNameHexDesc.length = sizeof (expNameHexBuf);
298 	if (!gsscred_AsHex(expName, &expNameHexDesc))
299 		return (0);
300 
301 	if (tableSource == GSSCRED_FLAT_FILE)
302 		return (file_getGssCredUid(&expNameHexDesc, uid));
303 
304 	return (0);  /* XXX for new backends (ldap, dss), 0->1 probably */
305 } /* gss_getGssCredEntry */
306