1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2021-2023, Juniper Networks, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 */ 29 30 #include <sys/types.h> 31 #include <sys/errno.h> 32 #include <sys/mac.h> 33 34 #include <unistd.h> 35 #include <string.h> 36 37 #include <security/mac_veriexec/mac_veriexec.h> 38 39 /** 40 * @brief get veriexec params for a process 41 * 42 * @return 43 * @li 0 if successful 44 */ 45 int 46 veriexec_get_pid_params(pid_t pid, 47 struct mac_veriexec_syscall_params *params) 48 { 49 struct mac_veriexec_syscall_params_args args; 50 51 if (params == NULL) 52 return EINVAL; 53 54 args.u.pid = pid; 55 args.params = params; 56 return mac_syscall(MAC_VERIEXEC_NAME, 57 MAC_VERIEXEC_GET_PARAMS_PID_SYSCALL, &args); 58 } 59 60 /** 61 * @brief get veriexec params for a path 62 * 63 * @return 64 * @li 0 if successful 65 */ 66 int 67 veriexec_get_path_params(const char *file, 68 struct mac_veriexec_syscall_params *params) 69 { 70 struct mac_veriexec_syscall_params_args args; 71 72 if (file == NULL || params == NULL) 73 return EINVAL; 74 75 args.u.filename = file; 76 args.params = params; 77 return mac_syscall(MAC_VERIEXEC_NAME, 78 MAC_VERIEXEC_GET_PARAMS_PATH_SYSCALL, &args); 79 } 80 81 /** 82 * @brief return label associated with a path 83 * 84 * @param[in] file 85 * pathname of file to lookup. 86 * 87 * @prarm[in] buf 88 * if not NULL and big enough copy label to buf. 89 * otherwise return a copy of label. 90 * 91 * @param[in] bufsz 92 * size of buf, must be greater than found label length. 93 * 94 * @return 95 * @li NULL if no label 96 * @li pointer to label 97 */ 98 char * 99 veriexec_get_path_label(const char *file, char *buf, size_t bufsz) 100 { 101 struct mac_veriexec_syscall_params params; 102 char *cp; 103 104 cp = NULL; 105 if (veriexec_get_path_params(file, ¶ms) == 0) { 106 /* Does label contain a label */ 107 if (params.labellen > 0) { 108 if (buf != NULL && bufsz > params.labellen) { 109 strlcpy(buf, params.label, bufsz); 110 cp = buf; 111 } else 112 cp = strdup(params.label); 113 } 114 } 115 return cp; 116 } 117 118 /** 119 * @brief return label of a process 120 * 121 * 122 * @param[in] pid 123 * process id of interest. 124 * 125 * @prarm[in] buf 126 * if not NULL and big enough copy label to buf. 127 * otherwise return a copy of label. 128 * 129 * @param[in] bufsz 130 * size of buf, must be greater than found label length. 131 * 132 * @return 133 * @li NULL if no label 134 * @li pointer to label 135 */ 136 char * 137 veriexec_get_pid_label(pid_t pid, char *buf, size_t bufsz) 138 { 139 struct mac_veriexec_syscall_params params; 140 char *cp; 141 142 cp = NULL; 143 if (veriexec_get_pid_params(pid, ¶ms) == 0) { 144 /* Does label contain a label */ 145 if (params.labellen > 0) { 146 if (buf != NULL && bufsz > params.labellen) { 147 strlcpy(buf, params.label, bufsz); 148 cp = buf; 149 } else 150 cp = strdup(params.label); 151 } 152 } 153 return cp; 154 } 155 156 /* 157 * we match 158 * ^want$ 159 * ^want, 160 * ,want, 161 * ,want$ 162 * 163 * and if want ends with / then we match that prefix too. 164 */ 165 static int 166 check_label_want(const char *label, size_t labellen, 167 const char *want, size_t wantlen) 168 { 169 char *cp; 170 171 /* Does label contain [,]<want>[,] ? */ 172 if (labellen > 0 && wantlen > 0 && 173 (cp = strstr(label, want)) != NULL) { 174 if (cp == label || cp[-1] == ',') { 175 if (cp[wantlen] == '\0' || cp[wantlen] == ',' || 176 (cp[wantlen-1] == '/' && want[wantlen-1] == '/')) 177 return 1; /* yes */ 178 } 179 } 180 return 0; /* no */ 181 } 182 183 /** 184 * @brief check if a process has label that contains what we want 185 * 186 * @param[in] pid 187 * process id of interest. 188 * 189 * @param[in] want 190 * the label we are looking for 191 * if want ends with ``/`` it is assumed a prefix 192 * otherwise we expect it to be followed by ``,`` or end of string. 193 * 194 * @return 195 * @li 0 if no 196 * @li 1 if yes 197 */ 198 int 199 veriexec_check_pid_label(pid_t pid, const char *want) 200 { 201 struct mac_veriexec_syscall_params params; 202 size_t n; 203 204 if (want != NULL && 205 (n = strlen(want)) > 0 && 206 veriexec_get_pid_params(pid, ¶ms) == 0) { 207 return check_label_want(params.label, params.labellen, 208 want, n); 209 } 210 return 0; /* no */ 211 } 212 213 /** 214 * @brief check if a path has label that contains what we want 215 * 216 * @param[in] path 217 * pathname of interest. 218 * 219 * @param[in] want 220 * the label we are looking for 221 * if want ends with ``/`` it is assumed a prefix 222 * otherwise we expect it to be followed by ``,`` or end of string. 223 * 224 * @return 225 * @li 0 if no 226 * @li 1 if yes 227 */ 228 int 229 veriexec_check_path_label(const char *file, const char *want) 230 { 231 struct mac_veriexec_syscall_params params; 232 size_t n; 233 234 if (want != NULL && file != NULL && 235 (n = strlen(want)) > 0 && 236 veriexec_get_path_params(file, ¶ms) == 0) { 237 return check_label_want(params.label, params.labellen, 238 want, n); 239 } 240 return 0; /* no */ 241 } 242 243 #ifdef UNIT_TEST 244 #include <stdlib.h> 245 #include <stdio.h> 246 #include <err.h> 247 248 static char * 249 hash2hex(char *type, unsigned char *digest) 250 { 251 static char buf[2*MAXFINGERPRINTLEN+1]; 252 size_t n; 253 int i; 254 255 if (strcmp(type, "SHA1") == 0) { 256 n = 20; 257 } else if (strcmp(type, "SHA256") == 0) { 258 n = 32; 259 } else if (strcmp(type, "SHA384") == 0) { 260 n = 48; 261 } 262 for (i = 0; i < n; i++) { 263 sprintf(&buf[2*i], "%02x", (unsigned)digest[i]); 264 } 265 return buf; 266 } 267 268 int 269 main(int argc, char *argv[]) 270 { 271 struct mac_veriexec_syscall_params params; 272 pid_t pid; 273 char buf[BUFSIZ]; 274 const char *cp; 275 char *want = NULL; 276 int lflag = 0; 277 int pflag = 0; 278 int error; 279 int c; 280 281 while ((c = getopt(argc, argv, "lpw:")) != -1) { 282 switch (c) { 283 case 'l': 284 lflag = 1; 285 break; 286 case 'p': 287 pflag = 1; 288 break; 289 case 'w': 290 want = optarg; 291 break; 292 default: 293 break; 294 } 295 } 296 for (; optind < argc; optind++) { 297 298 if (pflag) { 299 pid = atoi(argv[optind]); 300 if (lflag) { 301 cp = veriexec_get_pid_label(pid, buf, sizeof(buf)); 302 if (cp) 303 printf("pid=%d label='%s'\n", pid, cp); 304 continue; 305 } 306 if (want) { 307 error = veriexec_check_pid_label(pid, want); 308 printf("pid=%d want='%s': %d\n", 309 pid, want, error); 310 continue; 311 } 312 error = veriexec_get_pid_params(pid, ¶ms); 313 } else { 314 if (lflag) { 315 cp = veriexec_get_path_label(argv[optind], 316 buf, sizeof(buf)); 317 if (cp) 318 printf("path='%s' label='%s'\n", 319 argv[optind], cp); 320 continue; 321 } 322 if (want) { 323 error = veriexec_check_path_label(argv[optind], want); 324 printf("path='%s' want='%s': %d\n", 325 argv[optind], want, error); 326 continue; 327 } 328 error = veriexec_get_path_params(argv[optind], ¶ms); 329 } 330 if (error) { 331 err(2, "%s, error=%d", argv[optind], error); 332 } 333 334 printf("arg=%s, type=%s, flags=%u, label='%s', fingerprint='%s'\n", 335 argv[optind], params.fp_type, (unsigned)params.flags, 336 params.label, 337 hash2hex(params.fp_type, params.fingerprint)); 338 } 339 return 0; 340 } 341 #endif 342