1 /*- 2 * Copyright (c) 2005 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include <gssapi/gssapi.h> 30 #include <ctype.h> 31 #include <dlfcn.h> 32 #include <errno.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 37 #include "mech_switch.h" 38 #include "utils.h" 39 40 #ifndef _PATH_GSS_MECH 41 #define _PATH_GSS_MECH "/etc/gss/mech" 42 #endif 43 44 struct _gss_mech_switch_list _gss_mechs = 45 SLIST_HEAD_INITIALIZER(_gss_mechs); 46 gss_OID_set _gss_mech_oids; 47 48 /* 49 * Convert a string containing an OID in 'dot' form 50 * (e.g. 1.2.840.113554.1.2.2) to a gss_OID. 51 */ 52 static int 53 _gss_string_to_oid(const char* s, gss_OID oid) 54 { 55 int number_count, i, j; 56 int byte_count; 57 const char *p, *q; 58 char *res; 59 60 oid->length = 0; 61 oid->elements = NULL; 62 63 /* 64 * First figure out how many numbers in the oid, then 65 * calculate the compiled oid size. 66 */ 67 number_count = 0; 68 for (p = s; p; p = q) { 69 q = strchr(p, '.'); 70 if (q) q = q + 1; 71 number_count++; 72 } 73 74 /* 75 * The first two numbers are in the first byte and each 76 * subsequent number is encoded in a variable byte sequence. 77 */ 78 if (number_count < 2) 79 return (EINVAL); 80 81 /* 82 * We do this in two passes. The first pass, we just figure 83 * out the size. Second time around, we actually encode the 84 * number. 85 */ 86 res = NULL; 87 for (i = 0; i < 2; i++) { 88 byte_count = 0; 89 for (p = s, j = 0; p; p = q, j++) { 90 unsigned int number = 0; 91 92 /* 93 * Find the end of this number. 94 */ 95 q = strchr(p, '.'); 96 if (q) q = q + 1; 97 98 /* 99 * Read the number of of the string. Don't 100 * bother with anything except base ten. 101 */ 102 while (*p && *p != '.') { 103 number = 10 * number + (*p - '0'); 104 p++; 105 } 106 107 /* 108 * Encode the number. The first two numbers 109 * are packed into the first byte. Subsequent 110 * numbers are encoded in bytes seven bits at 111 * a time with the last byte having the high 112 * bit set. 113 */ 114 if (j == 0) { 115 if (res) 116 *res = number * 40; 117 } else if (j == 1) { 118 if (res) { 119 *res += number; 120 res++; 121 } 122 byte_count++; 123 } else if (j >= 2) { 124 /* 125 * The number is encoded in seven bit chunks. 126 */ 127 unsigned int t; 128 int bytes; 129 130 bytes = 0; 131 for (t = number; t; t >>= 7) 132 bytes++; 133 if (bytes == 0) bytes = 1; 134 while (bytes) { 135 if (res) { 136 int bit = 7*(bytes-1); 137 138 *res = (number >> bit) & 0x7f; 139 if (bytes != 1) 140 *res |= 0x80; 141 res++; 142 } 143 byte_count++; 144 bytes--; 145 } 146 } 147 } 148 if (!res) { 149 res = malloc(byte_count); 150 if (!res) 151 return (ENOMEM); 152 oid->length = byte_count; 153 oid->elements = res; 154 } 155 } 156 157 return (0); 158 } 159 160 161 #define SYM(name) \ 162 do { \ 163 snprintf(buf, sizeof(buf), "%s_%s", \ 164 m->gm_name_prefix, #name); \ 165 m->gm_ ## name = dlsym(so, buf); \ 166 if (!m->gm_ ## name) { \ 167 fprintf(stderr, "can't find symbol %s\n", buf); \ 168 goto bad; \ 169 } \ 170 } while (0) 171 172 #define OPTSYM(name) \ 173 do { \ 174 snprintf(buf, sizeof(buf), "%s_%s", \ 175 m->gm_name_prefix, #name); \ 176 m->gm_ ## name = dlsym(so, buf); \ 177 } while (0) 178 179 /* 180 * Load the mechanisms file (/etc/gss/mech). 181 */ 182 void 183 _gss_load_mech(void) 184 { 185 OM_uint32 major_status, minor_status; 186 FILE *fp; 187 char buf[256]; 188 char *p; 189 char *name, *oid, *lib, *kobj; 190 struct _gss_mech_switch *m; 191 int count; 192 void *so; 193 const char *(*prefix_fn)(void); 194 195 if (SLIST_FIRST(&_gss_mechs)) 196 return; 197 198 major_status = gss_create_empty_oid_set(&minor_status, 199 &_gss_mech_oids); 200 if (major_status) 201 return; 202 203 fp = fopen(_PATH_GSS_MECH, "r"); 204 if (!fp) { 205 perror(_PATH_GSS_MECH); 206 return; 207 } 208 209 count = 0; 210 while (fgets(buf, sizeof(buf), fp)) { 211 if (*buf == '#') 212 continue; 213 p = buf; 214 name = strsep(&p, "\t\n "); 215 if (p) while (isspace(*p)) p++; 216 oid = strsep(&p, "\t\n "); 217 if (p) while (isspace(*p)) p++; 218 lib = strsep(&p, "\t\n "); 219 if (p) while (isspace(*p)) p++; 220 kobj = strsep(&p, "\t\n "); 221 if (!name || !oid || !lib || !kobj) 222 continue; 223 224 so = dlopen(lib, RTLD_LOCAL); 225 if (!so) { 226 fprintf(stderr, "dlopen: %s\n", dlerror()); 227 continue; 228 } 229 230 m = malloc(sizeof(struct _gss_mech_switch)); 231 if (!m) 232 break; 233 m->gm_so = so; 234 if (_gss_string_to_oid(oid, &m->gm_mech_oid)) { 235 free(m); 236 continue; 237 } 238 239 prefix_fn = (const char *(*)(void)) 240 dlsym(so, "_gss_name_prefix"); 241 if (prefix_fn) 242 m->gm_name_prefix = prefix_fn(); 243 else 244 m->gm_name_prefix = "gss"; 245 246 major_status = gss_add_oid_set_member(&minor_status, 247 &m->gm_mech_oid, &_gss_mech_oids); 248 if (major_status) { 249 free(m->gm_mech_oid.elements); 250 free(m); 251 continue; 252 } 253 254 SYM(acquire_cred); 255 SYM(release_cred); 256 SYM(init_sec_context); 257 SYM(accept_sec_context); 258 SYM(process_context_token); 259 SYM(delete_sec_context); 260 SYM(context_time); 261 SYM(get_mic); 262 SYM(verify_mic); 263 SYM(wrap); 264 SYM(unwrap); 265 SYM(display_status); 266 OPTSYM(indicate_mechs); 267 SYM(compare_name); 268 SYM(display_name); 269 SYM(import_name); 270 SYM(export_name); 271 SYM(release_name); 272 SYM(inquire_cred); 273 SYM(inquire_context); 274 SYM(wrap_size_limit); 275 SYM(add_cred); 276 SYM(inquire_cred_by_mech); 277 SYM(export_sec_context); 278 SYM(import_sec_context); 279 SYM(inquire_names_for_mech); 280 SYM(inquire_mechs_for_name); 281 SYM(canonicalize_name); 282 SYM(duplicate_name); 283 OPTSYM(inquire_sec_context_by_oid); 284 OPTSYM(inquire_cred_by_oid); 285 OPTSYM(set_sec_context_option); 286 OPTSYM(set_cred_option); 287 OPTSYM(pseudo_random); 288 OPTSYM(pname_to_uid); 289 290 SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link); 291 count++; 292 continue; 293 294 bad: 295 free(m->gm_mech_oid.elements); 296 free(m); 297 dlclose(so); 298 continue; 299 } 300 fclose(fp); 301 } 302 303 struct _gss_mech_switch * 304 _gss_find_mech_switch(gss_OID mech) 305 { 306 struct _gss_mech_switch *m; 307 308 _gss_load_mech(); 309 SLIST_FOREACH(m, &_gss_mechs, gm_link) { 310 if (gss_oid_equal(&m->gm_mech_oid, mech)) 311 return m; 312 } 313 return (0); 314 } 315