1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /* lib/krad/attr.c - RADIUS attribute functions for libkrad */
3 /*
4 * Copyright 2013 Red Hat, Inc. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
18 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
20 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
21 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
24 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
25 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
26 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include <k5-int.h>
31 #include "internal.h"
32
33 #include <string.h>
34
35 /* RFC 2865 */
36 #define BLOCKSIZE 16
37
38 typedef krb5_error_code
39 (*attribute_transform_fn)(krb5_context ctx, const char *secret,
40 const unsigned char *auth, const krb5_data *in,
41 unsigned char outbuf[MAX_ATTRSIZE], size_t *outlen);
42
43 typedef struct {
44 const char *name;
45 unsigned char minval;
46 unsigned char maxval;
47 attribute_transform_fn encode;
48 attribute_transform_fn decode;
49 } attribute_record;
50
51 static krb5_error_code
52 user_password_encode(krb5_context ctx, const char *secret,
53 const unsigned char *auth, const krb5_data *in,
54 unsigned char outbuf[MAX_ATTRSIZE], size_t *outlen);
55
56 static krb5_error_code
57 user_password_decode(krb5_context ctx, const char *secret,
58 const unsigned char *auth, const krb5_data *in,
59 unsigned char outbuf[MAX_ATTRSIZE], size_t *outlen);
60
61 static const attribute_record attributes[UCHAR_MAX] = {
62 {"User-Name", 1, MAX_ATTRSIZE, NULL, NULL},
63 {"User-Password", 1, 128, user_password_encode, user_password_decode},
64 {"CHAP-Password", 17, 17, NULL, NULL},
65 {"NAS-IP-Address", 4, 4, NULL, NULL},
66 {"NAS-Port", 4, 4, NULL, NULL},
67 {"Service-Type", 4, 4, NULL, NULL},
68 {"Framed-Protocol", 4, 4, NULL, NULL},
69 {"Framed-IP-Address", 4, 4, NULL, NULL},
70 {"Framed-IP-Netmask", 4, 4, NULL, NULL},
71 {"Framed-Routing", 4, 4, NULL, NULL},
72 {"Filter-Id", 1, MAX_ATTRSIZE, NULL, NULL},
73 {"Framed-MTU", 4, 4, NULL, NULL},
74 {"Framed-Compression", 4, 4, NULL, NULL},
75 {"Login-IP-Host", 4, 4, NULL, NULL},
76 {"Login-Service", 4, 4, NULL, NULL},
77 {"Login-TCP-Port", 4, 4, NULL, NULL},
78 {NULL, 0, 0, NULL, NULL}, /* Unassigned */
79 {"Reply-Message", 1, MAX_ATTRSIZE, NULL, NULL},
80 {"Callback-Number", 1, MAX_ATTRSIZE, NULL, NULL},
81 {"Callback-Id", 1, MAX_ATTRSIZE, NULL, NULL},
82 {NULL, 0, 0, NULL, NULL}, /* Unassigned */
83 {"Framed-Route", 1, MAX_ATTRSIZE, NULL, NULL},
84 {"Framed-IPX-Network", 4, 4, NULL, NULL},
85 {"State", 1, MAX_ATTRSIZE, NULL, NULL},
86 {"Class", 1, MAX_ATTRSIZE, NULL, NULL},
87 {"Vendor-Specific", 5, MAX_ATTRSIZE, NULL, NULL},
88 {"Session-Timeout", 4, 4, NULL, NULL},
89 {"Idle-Timeout", 4, 4, NULL, NULL},
90 {"Termination-Action", 4, 4, NULL, NULL},
91 {"Called-Station-Id", 1, MAX_ATTRSIZE, NULL, NULL},
92 {"Calling-Station-Id", 1, MAX_ATTRSIZE, NULL, NULL},
93 {"NAS-Identifier", 1, MAX_ATTRSIZE, NULL, NULL},
94 {"Proxy-State", 1, MAX_ATTRSIZE, NULL, NULL},
95 {"Login-LAT-Service", 1, MAX_ATTRSIZE, NULL, NULL},
96 {"Login-LAT-Node", 1, MAX_ATTRSIZE, NULL, NULL},
97 {"Login-LAT-Group", 32, 32, NULL, NULL},
98 {"Framed-AppleTalk-Link", 4, 4, NULL, NULL},
99 {"Framed-AppleTalk-Network", 4, 4, NULL, NULL},
100 {"Framed-AppleTalk-Zone", 1, MAX_ATTRSIZE, NULL, NULL},
101 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
102 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
103 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
104 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
105 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
106 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
107 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
108 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
109 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
110 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
111 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
112 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
113 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
114 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
115 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
116 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
117 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
118 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
119 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
120 {NULL, 0, 0, NULL, NULL}, /* Reserved for accounting */
121 {"CHAP-Challenge", 5, MAX_ATTRSIZE, NULL, NULL},
122 {"NAS-Port-Type", 4, 4, NULL, NULL},
123 {"Port-Limit", 4, 4, NULL, NULL},
124 {"Login-LAT-Port", 1, MAX_ATTRSIZE, NULL, NULL},
125 };
126
127 /* Encode User-Password attribute. */
128 static krb5_error_code
user_password_encode(krb5_context ctx,const char * secret,const unsigned char * auth,const krb5_data * in,unsigned char outbuf[MAX_ATTRSIZE],size_t * outlen)129 user_password_encode(krb5_context ctx, const char *secret,
130 const unsigned char *auth, const krb5_data *in,
131 unsigned char outbuf[MAX_ATTRSIZE], size_t *outlen)
132 {
133 const unsigned char *indx;
134 krb5_error_code retval;
135 unsigned int seclen;
136 krb5_checksum sum;
137 size_t blck, len, i;
138 krb5_data tmp;
139
140 /* Copy the input buffer to the (zero-padded) output buffer. */
141 len = (in->length + BLOCKSIZE - 1) / BLOCKSIZE * BLOCKSIZE;
142 if (len > MAX_ATTRSIZE)
143 return ENOBUFS;
144 memset(outbuf, 0, len);
145 memcpy(outbuf, in->data, in->length);
146
147 /* Create our temporary space for processing each block. */
148 seclen = strlen(secret);
149 retval = alloc_data(&tmp, seclen + BLOCKSIZE);
150 if (retval != 0)
151 return retval;
152
153 memcpy(tmp.data, secret, seclen);
154 for (blck = 0, indx = auth; blck * BLOCKSIZE < len; blck++) {
155 memcpy(tmp.data + seclen, indx, BLOCKSIZE);
156
157 retval = krb5_c_make_checksum(ctx, CKSUMTYPE_RSA_MD5, NULL, 0, &tmp,
158 &sum);
159 if (retval != 0) {
160 zap(tmp.data, tmp.length);
161 zap(outbuf, len);
162 krb5_free_data_contents(ctx, &tmp);
163 return retval;
164 }
165
166 for (i = 0; i < BLOCKSIZE; i++)
167 outbuf[blck * BLOCKSIZE + i] ^= sum.contents[i];
168 krb5_free_checksum_contents(ctx, &sum);
169
170 indx = &outbuf[blck * BLOCKSIZE];
171 }
172
173 zap(tmp.data, tmp.length);
174 krb5_free_data_contents(ctx, &tmp);
175 *outlen = len;
176 return 0;
177 }
178
179 /* Decode User-Password attribute. */
180 static krb5_error_code
user_password_decode(krb5_context ctx,const char * secret,const unsigned char * auth,const krb5_data * in,unsigned char outbuf[MAX_ATTRSIZE],size_t * outlen)181 user_password_decode(krb5_context ctx, const char *secret,
182 const unsigned char *auth, const krb5_data *in,
183 unsigned char outbuf[MAX_ATTRSIZE], size_t *outlen)
184 {
185 const unsigned char *indx;
186 krb5_error_code retval;
187 unsigned int seclen;
188 krb5_checksum sum;
189 ssize_t blck, i;
190 krb5_data tmp;
191
192 if (in->length % BLOCKSIZE != 0)
193 return EINVAL;
194 if (in->length > MAX_ATTRSIZE)
195 return ENOBUFS;
196
197 /* Create our temporary space for processing each block. */
198 seclen = strlen(secret);
199 retval = alloc_data(&tmp, seclen + BLOCKSIZE);
200 if (retval != 0)
201 return retval;
202
203 memcpy(tmp.data, secret, seclen);
204 for (blck = 0, indx = auth; blck * BLOCKSIZE < in->length; blck++) {
205 memcpy(tmp.data + seclen, indx, BLOCKSIZE);
206
207 retval = krb5_c_make_checksum(ctx, CKSUMTYPE_RSA_MD5, NULL, 0,
208 &tmp, &sum);
209 if (retval != 0) {
210 zap(tmp.data, tmp.length);
211 zap(outbuf, in->length);
212 krb5_free_data_contents(ctx, &tmp);
213 return retval;
214 }
215
216 for (i = 0; i < BLOCKSIZE; i++) {
217 outbuf[blck * BLOCKSIZE + i] = in->data[blck * BLOCKSIZE + i] ^
218 sum.contents[i];
219 }
220 krb5_free_checksum_contents(ctx, &sum);
221
222 indx = (const unsigned char *)&in->data[blck * BLOCKSIZE];
223 }
224
225 /* Strip off trailing NULL bytes. */
226 *outlen = in->length;
227 while (*outlen > 0 && outbuf[*outlen - 1] == '\0')
228 (*outlen)--;
229
230 krb5_free_data_contents(ctx, &tmp);
231 return 0;
232 }
233
234 krb5_error_code
kr_attr_valid(krad_attr type,const krb5_data * data)235 kr_attr_valid(krad_attr type, const krb5_data *data)
236 {
237 const attribute_record *ar;
238
239 if (type == 0)
240 return EINVAL;
241
242 ar = &attributes[type - 1];
243 return (data->length >= ar->minval && data->length <= ar->maxval) ? 0 :
244 EMSGSIZE;
245 }
246
247 krb5_error_code
kr_attr_encode(krb5_context ctx,const char * secret,const unsigned char * auth,krad_attr type,const krb5_data * in,unsigned char outbuf[MAX_ATTRSIZE],size_t * outlen)248 kr_attr_encode(krb5_context ctx, const char *secret,
249 const unsigned char *auth, krad_attr type,
250 const krb5_data *in, unsigned char outbuf[MAX_ATTRSIZE],
251 size_t *outlen)
252 {
253 krb5_error_code retval;
254
255 retval = kr_attr_valid(type, in);
256 if (retval != 0)
257 return retval;
258
259 if (attributes[type - 1].encode == NULL) {
260 if (in->length > MAX_ATTRSIZE)
261 return ENOBUFS;
262
263 *outlen = in->length;
264 memcpy(outbuf, in->data, in->length);
265 return 0;
266 }
267
268 return attributes[type - 1].encode(ctx, secret, auth, in, outbuf, outlen);
269 }
270
271 krb5_error_code
kr_attr_decode(krb5_context ctx,const char * secret,const unsigned char * auth,krad_attr type,const krb5_data * in,unsigned char outbuf[MAX_ATTRSIZE],size_t * outlen)272 kr_attr_decode(krb5_context ctx, const char *secret, const unsigned char *auth,
273 krad_attr type, const krb5_data *in,
274 unsigned char outbuf[MAX_ATTRSIZE], size_t *outlen)
275 {
276 krb5_error_code retval;
277
278 retval = kr_attr_valid(type, in);
279 if (retval != 0)
280 return retval;
281
282 if (attributes[type - 1].encode == NULL) {
283 if (in->length > MAX_ATTRSIZE)
284 return ENOBUFS;
285
286 *outlen = in->length;
287 memcpy(outbuf, in->data, in->length);
288 return 0;
289 }
290
291 return attributes[type - 1].decode(ctx, secret, auth, in, outbuf, outlen);
292 }
293
294 krad_attr
krad_attr_name2num(const char * name)295 krad_attr_name2num(const char *name)
296 {
297 unsigned char i;
298
299 for (i = 0; i < UCHAR_MAX; i++) {
300 if (attributes[i].name == NULL)
301 continue;
302
303 if (strcmp(attributes[i].name, name) == 0)
304 return i + 1;
305 }
306
307 return 0;
308 }
309
310 const char *
krad_attr_num2name(krad_attr type)311 krad_attr_num2name(krad_attr type)
312 {
313 if (type == 0)
314 return NULL;
315
316 return attributes[type - 1].name;
317 }
318