| 1 | /* |
| 2 | ashd - A Sane HTTP Daemon |
| 3 | Copyright (C) 2008 Fredrik Tolf <fredrik@dolda2000.com> |
| 4 | |
| 5 | This program is free software: you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation, either version 3 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | */ |
| 18 | |
| 19 | #include <stdlib.h> |
| 20 | #include <stdio.h> |
| 21 | #include <unistd.h> |
| 22 | #include <string.h> |
| 23 | #include <errno.h> |
| 24 | #include <sys/poll.h> |
| 25 | #include <sys/wait.h> |
| 26 | #include <time.h> |
| 27 | #include <signal.h> |
| 28 | |
| 29 | #ifdef HAVE_CONFIG_H |
| 30 | #include <config.h> |
| 31 | #endif |
| 32 | #include <utils.h> |
| 33 | #include <log.h> |
| 34 | #include <req.h> |
| 35 | #include <proc.h> |
| 36 | #include <resp.h> |
| 37 | |
| 38 | struct cache { |
| 39 | struct cache *next, *prev; |
| 40 | char *user, *pass; |
| 41 | time_t lastuse; |
| 42 | }; |
| 43 | |
| 44 | static int ch; |
| 45 | static char **authcmd; |
| 46 | static char *realm; |
| 47 | static int docache = 1, reqssl; |
| 48 | static struct cache *cache; |
| 49 | static time_t now, lastclean; |
| 50 | |
| 51 | static int auth(struct hthead *req, int fd, char *user, char *pass); |
| 52 | |
| 53 | static void reqauth(struct hthead *req, int fd) |
| 54 | { |
| 55 | struct charbuf buf; |
| 56 | FILE *out; |
| 57 | char *rn; |
| 58 | |
| 59 | rn = realm; |
| 60 | if(rn == NULL) |
| 61 | rn = "auth"; |
| 62 | bufinit(buf); |
| 63 | bufcatstr(buf, "<?xml version=\"1.0\" encoding=\"US-ASCII\"?>\r\n"); |
| 64 | bufcatstr(buf, "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\r\n"); |
| 65 | bufcatstr(buf, "<html xmlns=\"http://www.w3.org/1999/xhtml\" lang=\"en-US\" xml:lang=\"en-US\">\r\n"); |
| 66 | bufcatstr(buf, "<head>\r\n"); |
| 67 | bprintf(&buf, "<title>Authentication Required</title>\r\n"); |
| 68 | bufcatstr(buf, "</head>\r\n"); |
| 69 | bufcatstr(buf, "<body>\r\n"); |
| 70 | bprintf(&buf, "<h1>Authentication Required</h1>\r\n"); |
| 71 | bprintf(&buf, "<p>You need to authenticate to access the requested resource.</p>\r\n"); |
| 72 | bufcatstr(buf, "</body>\r\n"); |
| 73 | bufcatstr(buf, "</html>\r\n"); |
| 74 | out = fdopen(dup(fd), "w"); |
| 75 | fprintf(out, "HTTP/1.1 401 Authentication Required\n"); |
| 76 | fprintf(out, "WWW-Authenticate: Basic realm=\"%s\"\n", rn); |
| 77 | fprintf(out, "Content-Type: text/html\n"); |
| 78 | fprintf(out, "Content-Length: %zi\n", buf.d); |
| 79 | fprintf(out, "\n"); |
| 80 | fwrite(buf.b, 1, buf.d, out); |
| 81 | fclose(out); |
| 82 | buffree(buf); |
| 83 | } |
| 84 | |
| 85 | static void authinval(struct hthead *req, int fd, char *msg) |
| 86 | { |
| 87 | struct charbuf buf; |
| 88 | FILE *out; |
| 89 | char *rn; |
| 90 | |
| 91 | rn = realm; |
| 92 | if(rn == NULL) |
| 93 | rn = "auth"; |
| 94 | bufinit(buf); |
| 95 | bufcatstr(buf, "<?xml version=\"1.0\" encoding=\"US-ASCII\"?>\r\n"); |
| 96 | bufcatstr(buf, "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\r\n"); |
| 97 | bufcatstr(buf, "<html xmlns=\"http://www.w3.org/1999/xhtml\" lang=\"en-US\" xml:lang=\"en-US\">\r\n"); |
| 98 | bufcatstr(buf, "<head>\r\n"); |
| 99 | bprintf(&buf, "<title>Invalid authentication</title>\r\n"); |
| 100 | bufcatstr(buf, "</head>\r\n"); |
| 101 | bufcatstr(buf, "<body>\r\n"); |
| 102 | bprintf(&buf, "<h1>Invalid authentication</h1>\r\n"); |
| 103 | bprintf(&buf, "<p>%s</p>\r\n", htmlquote(msg)); |
| 104 | bufcatstr(buf, "</body>\r\n"); |
| 105 | bufcatstr(buf, "</html>\r\n"); |
| 106 | out = fdopen(dup(fd), "w"); |
| 107 | fprintf(out, "HTTP/1.1 401 Invalid authentication\n"); |
| 108 | fprintf(out, "WWW-Authenticate: Basic realm=\"%s\"\n", rn); |
| 109 | fprintf(out, "Content-Type: text/html\n"); |
| 110 | fprintf(out, "Content-Length: %zi\n", buf.d); |
| 111 | fprintf(out, "\n"); |
| 112 | fwrite(buf.b, 1, buf.d, out); |
| 113 | fclose(out); |
| 114 | buffree(buf); |
| 115 | } |
| 116 | |
| 117 | static void cleancache(int complete) |
| 118 | { |
| 119 | struct cache *c, *n; |
| 120 | |
| 121 | for(c = cache; c != NULL; c = n) { |
| 122 | n = c->next; |
| 123 | if(complete || (now - c->lastuse > 3600)) { |
| 124 | if(c->next) |
| 125 | c->next->prev = c->prev; |
| 126 | if(c->prev) |
| 127 | c->prev->next = c->next; |
| 128 | if(c == cache) |
| 129 | cache = c->next; |
| 130 | memset(c->pass, 0, strlen(c->pass)); |
| 131 | free(c->user); |
| 132 | free(c->pass); |
| 133 | free(c); |
| 134 | } |
| 135 | } |
| 136 | lastclean = now; |
| 137 | } |
| 138 | |
| 139 | static int ckcache(char *user, char *pass) |
| 140 | { |
| 141 | struct cache *c; |
| 142 | |
| 143 | for(c = cache; c != NULL; c = c->next) { |
| 144 | if(!strcmp(user, c->user) && !strcmp(pass, c->pass)) { |
| 145 | c->lastuse = now; |
| 146 | return(1); |
| 147 | } |
| 148 | } |
| 149 | return(0); |
| 150 | } |
| 151 | |
| 152 | static struct cache *addcache(char *user, char *pass) |
| 153 | { |
| 154 | struct cache *c; |
| 155 | |
| 156 | omalloc(c); |
| 157 | c->user = sstrdup(user); |
| 158 | c->pass = sstrdup(pass); |
| 159 | c->lastuse = now; |
| 160 | c->next = cache; |
| 161 | if(cache != NULL) |
| 162 | cache->prev = c; |
| 163 | cache = c; |
| 164 | return(c); |
| 165 | } |
| 166 | |
| 167 | static void serve2(struct hthead *req, int fd, char *user) |
| 168 | { |
| 169 | headappheader(req, "X-Ash-Remote-User", user); |
| 170 | if(sendreq(ch, req, fd)) { |
| 171 | flog(LOG_ERR, "htextauth: could not pass request to child: %s", strerror(errno)); |
| 172 | exit(1); |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | static void serve(struct hthead *req, int fd) |
| 177 | { |
| 178 | char *raw, *dec, *p; |
| 179 | size_t declen; |
| 180 | |
| 181 | now = time(NULL); |
| 182 | dec = NULL; |
| 183 | if(reqssl && (((raw = getheader(req, "X-Ash-Protocol")) == NULL) || strcmp(raw, "https"))) { |
| 184 | simpleerror(fd, 403, "Forbidden", "The requested resource must be requested over HTTPS."); |
| 185 | goto out; |
| 186 | } |
| 187 | if(((raw = getheader(req, "Authorization")) == NULL) || strncasecmp(raw, "basic ", 6)) { |
| 188 | reqauth(req, fd); |
| 189 | goto out; |
| 190 | } |
| 191 | if((dec = base64decode(raw + 6, &declen)) == NULL) { |
| 192 | simpleerror(fd, 400, "Invalid request", "The authentication data is not proper base64."); |
| 193 | goto out; |
| 194 | } |
| 195 | memset(raw, 0, strlen(raw)); |
| 196 | headrmheader(req, "Authorization"); |
| 197 | for(p = dec; *p; p++) { |
| 198 | if(*p < 32) { |
| 199 | simpleerror(fd, 400, "Invalid request", "The authentication data is invalid."); |
| 200 | goto out; |
| 201 | } |
| 202 | } |
| 203 | if((p = strchr(dec, ':')) == NULL) { |
| 204 | simpleerror(fd, 400, "Invalid request", "The authentication data is invalid."); |
| 205 | goto out; |
| 206 | } |
| 207 | *(p++) = 0; |
| 208 | if(docache && ckcache(dec, p)) { |
| 209 | serve2(req, fd, dec); |
| 210 | goto out; |
| 211 | } |
| 212 | if(auth(req, fd, dec, p)) { |
| 213 | if(docache) |
| 214 | addcache(dec, p); |
| 215 | serve2(req, fd, dec); |
| 216 | goto out; |
| 217 | } |
| 218 | |
| 219 | out: |
| 220 | if(dec != NULL) { |
| 221 | memset(dec, 0, declen); |
| 222 | free(dec); |
| 223 | } |
| 224 | if(docache && (now - lastclean > 60)) |
| 225 | cleancache(0); |
| 226 | } |
| 227 | |
| 228 | static int auth(struct hthead *req, int fd, char *user, char *pass) |
| 229 | { |
| 230 | int i, rv, status; |
| 231 | ssize_t len; |
| 232 | char *msg; |
| 233 | struct charbuf ebuf; |
| 234 | pid_t pid; |
| 235 | int pfd[2], efd[2]; |
| 236 | FILE *out; |
| 237 | |
| 238 | rv = 0; |
| 239 | msg = "The supplied credentials are invalid."; |
| 240 | pipe(pfd); |
| 241 | pipe(efd); |
| 242 | if((pid = fork()) < 0) { |
| 243 | flog(LOG_ERR, "htextauth: could not fork: %s", strerror(errno)); |
| 244 | simpleerror(fd, 500, "Server Error", "An internal error occurred."); |
| 245 | close(pfd[0]); close(pfd[1]); |
| 246 | close(efd[0]); close(efd[1]); |
| 247 | return(0); |
| 248 | } |
| 249 | if(pid == 0) { |
| 250 | dup2(pfd[0], 0); |
| 251 | dup2(efd[1], 1); |
| 252 | for(i = 3; i < FD_SETSIZE; i++) |
| 253 | close(i); |
| 254 | execvp(authcmd[0], authcmd); |
| 255 | flog(LOG_ERR, "htextauth: could not exec %s: %s", authcmd[0], strerror(errno)); |
| 256 | exit(127); |
| 257 | } |
| 258 | close(pfd[0]); |
| 259 | close(efd[1]); |
| 260 | out = fdopen(pfd[1], "w"); |
| 261 | fprintf(out, "%s\n", user); |
| 262 | fprintf(out, "%s\n", pass); |
| 263 | fclose(out); |
| 264 | bufinit(ebuf); |
| 265 | while(1) { |
| 266 | sizebuf(ebuf, ebuf.d + 128); |
| 267 | len = read(efd[0], ebuf.b + ebuf.d, ebuf.s - ebuf.d); |
| 268 | if(len < 0) { |
| 269 | if(errno == EINTR) |
| 270 | continue; |
| 271 | break; |
| 272 | } else if(len == 0) { |
| 273 | break; |
| 274 | } |
| 275 | ebuf.d += len; |
| 276 | } |
| 277 | if(ebuf.d > 0) { |
| 278 | bufadd(ebuf, 0); |
| 279 | msg = ebuf.b; |
| 280 | } |
| 281 | close(efd[0]); |
| 282 | if(waitpid(pid, &status, 0) < 0) { |
| 283 | flog(LOG_ERR, "htextauth: could not wait: %s", strerror(errno)); |
| 284 | simpleerror(fd, 500, "Server Error", "An internal error occurred."); |
| 285 | buffree(ebuf); |
| 286 | return(0); |
| 287 | } |
| 288 | if(WCOREDUMP(status)) |
| 289 | flog(LOG_WARNING, "htextauth: authenticator process dumped core"); |
| 290 | if(WIFEXITED(status) && (WEXITSTATUS(status) == 0)) |
| 291 | rv = 1; |
| 292 | else |
| 293 | authinval(req, fd, msg); |
| 294 | buffree(ebuf); |
| 295 | return(rv); |
| 296 | } |
| 297 | |
| 298 | static void usage(FILE *out) |
| 299 | { |
| 300 | fprintf(out, "usage: htextauth [-hCs] [-r REALM] AUTHCMD [ARGS...] -- CHILD [ARGS...]\n"); |
| 301 | } |
| 302 | |
| 303 | static void sighandler(int sig) |
| 304 | { |
| 305 | } |
| 306 | |
| 307 | int main(int argc, char **argv) |
| 308 | { |
| 309 | int i, c, ret; |
| 310 | struct charvbuf cbuf; |
| 311 | struct pollfd pfd[2]; |
| 312 | struct hthead *req; |
| 313 | int fd; |
| 314 | |
| 315 | while((c = getopt(argc, argv, "+hCsr:")) >= 0) { |
| 316 | switch(c) { |
| 317 | case 'h': |
| 318 | usage(stdout); |
| 319 | return(0); |
| 320 | case 'C': |
| 321 | docache = 0; |
| 322 | break; |
| 323 | case 's': |
| 324 | reqssl = 1; |
| 325 | break; |
| 326 | case 'r': |
| 327 | realm = optarg; |
| 328 | break; |
| 329 | default: |
| 330 | usage(stderr); |
| 331 | return(1); |
| 332 | } |
| 333 | } |
| 334 | bufinit(cbuf); |
| 335 | for(i = optind; i < argc; i++) { |
| 336 | if(!strcmp(argv[i], "--")) |
| 337 | break; |
| 338 | bufadd(cbuf, argv[i]); |
| 339 | } |
| 340 | if((cbuf.d == 0) || (i == argc)) { |
| 341 | usage(stderr); |
| 342 | return(1); |
| 343 | } |
| 344 | bufadd(cbuf, NULL); |
| 345 | authcmd = cbuf.b; |
| 346 | i++; |
| 347 | if(i == argc) { |
| 348 | usage(stderr); |
| 349 | return(1); |
| 350 | } |
| 351 | if((ch = stdmkchild(argv + i, NULL, NULL)) < 0) { |
| 352 | flog(LOG_ERR, "htextauth: could not fork child: %s", strerror(errno)); |
| 353 | return(1); |
| 354 | } |
| 355 | signal(SIGCHLD, sighandler); |
| 356 | signal(SIGPIPE, sighandler); |
| 357 | while(1) { |
| 358 | memset(pfd, 0, sizeof(pfd)); |
| 359 | pfd[0].fd = 0; |
| 360 | pfd[0].events = POLLIN; |
| 361 | pfd[1].fd = ch; |
| 362 | pfd[1].events = POLLHUP; |
| 363 | if((ret = poll(pfd, 2, -1)) < 0) { |
| 364 | if(errno != EINTR) { |
| 365 | flog(LOG_ERR, "htextauth: error in poll: %s", strerror(errno)); |
| 366 | exit(1); |
| 367 | } |
| 368 | } |
| 369 | if(pfd[0].revents) { |
| 370 | if((fd = recvreq(0, &req)) < 0) { |
| 371 | if(errno == 0) |
| 372 | break; |
| 373 | flog(LOG_ERR, "htextauth: error in recvreq: %s", strerror(errno)); |
| 374 | exit(1); |
| 375 | } |
| 376 | serve(req, fd); |
| 377 | freehthead(req); |
| 378 | close(fd); |
| 379 | } |
| 380 | if(pfd[1].revents & POLLHUP) |
| 381 | break; |
| 382 | } |
| 383 | cleancache(1); |
| 384 | return(0); |
| 385 | } |