Annotation of src/usr.bin/ssh/auth-options.c, Revision 1.101
1.101 ! dtucker 1: /* $OpenBSD: auth-options.c,v 1.100 2023/07/14 05:31:44 djm Exp $ */
1.75 djm 2: /*
3: * Copyright (c) 2018 Damien Miller <djm@mindrot.org>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
1.3 deraadt 17:
1.36 stevesk 18: #include <sys/types.h>
1.42 djm 19: #include <sys/queue.h>
1.36 stevesk 20:
1.88 djm 21: #include <stdlib.h>
1.37 stevesk 22: #include <netdb.h>
1.36 stevesk 23: #include <pwd.h>
1.39 stevesk 24: #include <string.h>
1.40 deraadt 25: #include <stdio.h>
1.101 ! dtucker 26: #include <stdint.h>
1.40 deraadt 27: #include <stdarg.h>
1.75 djm 28: #include <ctype.h>
29: #include <limits.h>
1.1 markus 30:
31: #include "xmalloc.h"
1.65 markus 32: #include "ssherr.h"
1.11 markus 33: #include "log.h"
1.65 markus 34: #include "sshbuf.h"
1.64 millert 35: #include "misc.h"
1.65 markus 36: #include "sshkey.h"
1.76 djm 37: #include "match.h"
38: #include "ssh2.h"
1.50 djm 39: #include "auth-options.h"
1.75 djm 40:
41: static int
42: dup_strings(char ***dstp, size_t *ndstp, char **src, size_t nsrc)
43: {
44: char **dst;
45: size_t i, j;
46:
47: *dstp = NULL;
48: *ndstp = 0;
1.100 djm 49:
1.75 djm 50: if (nsrc == 0)
51: return 0;
1.100 djm 52: if (nsrc >= SIZE_MAX / sizeof(*src) ||
53: (dst = calloc(nsrc, sizeof(*src))) == NULL)
1.75 djm 54: return -1;
55: for (i = 0; i < nsrc; i++) {
56: if ((dst[i] = strdup(src[i])) == NULL) {
57: for (j = 0; j < i; j++)
58: free(dst[j]);
59: free(dst);
60: return -1;
61: }
62: }
63: /* success */
64: *dstp = dst;
65: *ndstp = nsrc;
66: return 0;
67: }
68:
69: #define OPTIONS_CRITICAL 1
70: #define OPTIONS_EXTENSIONS 2
71: static int
72: cert_option_list(struct sshauthopt *opts, struct sshbuf *oblob,
73: u_int which, int crit)
74: {
75: char *command, *allowed;
76: char *name = NULL;
77: struct sshbuf *c = NULL, *data = NULL;
78: int r, ret = -1, found;
79:
80: if ((c = sshbuf_fromb(oblob)) == NULL) {
1.94 djm 81: error_f("sshbuf_fromb failed");
1.75 djm 82: goto out;
83: }
84:
85: while (sshbuf_len(c) > 0) {
86: sshbuf_free(data);
87: data = NULL;
88: if ((r = sshbuf_get_cstring(c, &name, NULL)) != 0 ||
89: (r = sshbuf_froms(c, &data)) != 0) {
1.94 djm 90: error_r(r, "Unable to parse certificate options");
1.75 djm 91: goto out;
92: }
93: debug3("found certificate option \"%.100s\" len %zu",
94: name, sshbuf_len(data));
95: found = 0;
96: if ((which & OPTIONS_EXTENSIONS) != 0) {
1.90 djm 97: if (strcmp(name, "no-touch-required") == 0) {
98: opts->no_require_user_presence = 1;
99: found = 1;
100: } else if (strcmp(name, "permit-X11-forwarding") == 0) {
1.75 djm 101: opts->permit_x11_forwarding_flag = 1;
102: found = 1;
103: } else if (strcmp(name,
104: "permit-agent-forwarding") == 0) {
105: opts->permit_agent_forwarding_flag = 1;
106: found = 1;
107: } else if (strcmp(name,
108: "permit-port-forwarding") == 0) {
109: opts->permit_port_forwarding_flag = 1;
110: found = 1;
111: } else if (strcmp(name, "permit-pty") == 0) {
112: opts->permit_pty_flag = 1;
113: found = 1;
114: } else if (strcmp(name, "permit-user-rc") == 0) {
115: opts->permit_user_rc = 1;
116: found = 1;
117: }
118: }
119: if (!found && (which & OPTIONS_CRITICAL) != 0) {
1.93 djm 120: if (strcmp(name, "verify-required") == 0) {
121: opts->require_verify = 1;
122: found = 1;
123: } else if (strcmp(name, "force-command") == 0) {
1.75 djm 124: if ((r = sshbuf_get_cstring(data, &command,
125: NULL)) != 0) {
1.94 djm 126: error_r(r, "Unable to parse \"%s\" "
127: "section", name);
1.75 djm 128: goto out;
129: }
130: if (opts->force_command != NULL) {
131: error("Certificate has multiple "
132: "force-command options");
133: free(command);
134: goto out;
135: }
136: opts->force_command = command;
137: found = 1;
1.93 djm 138: } else if (strcmp(name, "source-address") == 0) {
1.75 djm 139: if ((r = sshbuf_get_cstring(data, &allowed,
140: NULL)) != 0) {
1.94 djm 141: error_r(r, "Unable to parse \"%s\" "
142: "section", name);
1.75 djm 143: goto out;
144: }
145: if (opts->required_from_host_cert != NULL) {
146: error("Certificate has multiple "
147: "source-address options");
148: free(allowed);
149: goto out;
150: }
151: /* Check syntax */
152: if (addr_match_cidr_list(NULL, allowed) == -1) {
153: error("Certificate source-address "
154: "contents invalid");
155: goto out;
156: }
157: opts->required_from_host_cert = allowed;
158: found = 1;
159: }
160: }
161:
162: if (!found) {
163: if (crit) {
164: error("Certificate critical option \"%s\" "
165: "is not supported", name);
166: goto out;
167: } else {
168: logit("Certificate extension \"%s\" "
169: "is not supported", name);
170: }
171: } else if (sshbuf_len(data) != 0) {
172: error("Certificate option \"%s\" corrupt "
173: "(extra data)", name);
174: goto out;
175: }
176: free(name);
177: name = NULL;
178: }
179: /* successfully parsed all options */
180: ret = 0;
181:
182: out:
183: free(name);
184: sshbuf_free(data);
185: sshbuf_free(c);
186: return ret;
187: }
188:
189: struct sshauthopt *
190: sshauthopt_new(void)
191: {
192: struct sshauthopt *ret;
193:
194: if ((ret = calloc(1, sizeof(*ret))) == NULL)
195: return NULL;
196: ret->force_tun_device = -1;
197: return ret;
198: }
199:
200: void
201: sshauthopt_free(struct sshauthopt *opts)
202: {
203: size_t i;
204:
205: if (opts == NULL)
206: return;
207:
208: free(opts->cert_principals);
209: free(opts->force_command);
210: free(opts->required_from_host_cert);
211: free(opts->required_from_host_keys);
212:
213: for (i = 0; i < opts->nenv; i++)
214: free(opts->env[i]);
215: free(opts->env);
216:
217: for (i = 0; i < opts->npermitopen; i++)
218: free(opts->permitopen[i]);
219: free(opts->permitopen);
220:
1.80 djm 221: for (i = 0; i < opts->npermitlisten; i++)
222: free(opts->permitlisten[i]);
223: free(opts->permitlisten);
224:
1.91 jsg 225: freezero(opts, sizeof(*opts));
1.75 djm 226: }
227:
228: struct sshauthopt *
229: sshauthopt_new_with_keys_defaults(void)
230: {
231: struct sshauthopt *ret = NULL;
232:
233: if ((ret = sshauthopt_new()) == NULL)
234: return NULL;
235:
236: /* Defaults for authorized_keys flags */
237: ret->permit_port_forwarding_flag = 1;
238: ret->permit_agent_forwarding_flag = 1;
239: ret->permit_x11_forwarding_flag = 1;
240: ret->permit_pty_flag = 1;
241: ret->permit_user_rc = 1;
242: return ret;
243: }
244:
1.80 djm 245: /*
246: * Parse and record a permitopen/permitlisten directive.
247: * Return 0 on success. Return -1 on failure and sets *errstrp to error reason.
248: */
249: static int
1.83 djm 250: handle_permit(const char **optsp, int allow_bare_port,
251: char ***permitsp, size_t *npermitsp, const char **errstrp)
1.80 djm 252: {
253: char *opt, *tmp, *cp, *host, **permits = *permitsp;
254: size_t npermits = *npermitsp;
255: const char *errstr = "unknown error";
256:
1.86 djm 257: if (npermits > SSH_AUTHOPT_PERMIT_MAX) {
1.80 djm 258: *errstrp = "too many permission directives";
259: return -1;
260: }
1.82 djm 261: if ((opt = opt_dequote(optsp, &errstr)) == NULL) {
1.80 djm 262: return -1;
263: }
1.83 djm 264: if (allow_bare_port && strchr(opt, ':') == NULL) {
265: /*
266: * Allow a bare port number in permitlisten to indicate a
267: * listen_host wildcard.
268: */
1.85 deraadt 269: if (asprintf(&tmp, "*:%s", opt) == -1) {
1.89 dtucker 270: free(opt);
1.83 djm 271: *errstrp = "memory allocation failed";
272: return -1;
273: }
274: free(opt);
275: opt = tmp;
276: }
1.80 djm 277: if ((tmp = strdup(opt)) == NULL) {
278: free(opt);
279: *errstrp = "memory allocation failed";
280: return -1;
281: }
282: cp = tmp;
283: /* validate syntax before recording it. */
1.98 dtucker 284: host = hpdelim2(&cp, NULL);
1.80 djm 285: if (host == NULL || strlen(host) >= NI_MAXHOST) {
286: free(tmp);
287: free(opt);
288: *errstrp = "invalid permission hostname";
289: return -1;
290: }
291: /*
292: * don't want to use permitopen_port to avoid
293: * dependency on channels.[ch] here.
294: */
295: if (cp == NULL ||
296: (strcmp(cp, "*") != 0 && a2port(cp) <= 0)) {
297: free(tmp);
298: free(opt);
299: *errstrp = "invalid permission port";
300: return -1;
301: }
302: /* XXX - add streamlocal support */
303: free(tmp);
304: /* Record it */
305: if ((permits = recallocarray(permits, npermits, npermits + 1,
306: sizeof(*permits))) == NULL) {
307: free(opt);
308: /* NB. don't update *permitsp if alloc fails */
309: *errstrp = "memory allocation failed";
310: return -1;
311: }
312: permits[npermits++] = opt;
313: *permitsp = permits;
314: *npermitsp = npermits;
315: return 0;
316: }
317:
1.75 djm 318: struct sshauthopt *
319: sshauthopt_parse(const char *opts, const char **errstrp)
320: {
1.80 djm 321: char **oarray, *opt, *cp, *tmp;
1.75 djm 322: int r;
323: struct sshauthopt *ret = NULL;
324: const char *errstr = "unknown error";
1.77 djm 325: uint64_t valid_before;
1.96 djm 326: size_t i, l;
1.75 djm 327:
328: if (errstrp != NULL)
329: *errstrp = NULL;
330: if ((ret = sshauthopt_new_with_keys_defaults()) == NULL)
331: goto alloc_fail;
332:
333: if (opts == NULL)
334: return ret;
335:
336: while (*opts && *opts != ' ' && *opts != '\t') {
337: /* flag options */
338: if ((r = opt_flag("restrict", 0, &opts)) != -1) {
339: ret->restricted = 1;
340: ret->permit_port_forwarding_flag = 0;
341: ret->permit_agent_forwarding_flag = 0;
342: ret->permit_x11_forwarding_flag = 0;
343: ret->permit_pty_flag = 0;
344: ret->permit_user_rc = 0;
345: } else if ((r = opt_flag("cert-authority", 0, &opts)) != -1) {
346: ret->cert_authority = r;
347: } else if ((r = opt_flag("port-forwarding", 1, &opts)) != -1) {
348: ret->permit_port_forwarding_flag = r == 1;
349: } else if ((r = opt_flag("agent-forwarding", 1, &opts)) != -1) {
350: ret->permit_agent_forwarding_flag = r == 1;
351: } else if ((r = opt_flag("x11-forwarding", 1, &opts)) != -1) {
352: ret->permit_x11_forwarding_flag = r == 1;
1.90 djm 353: } else if ((r = opt_flag("touch-required", 1, &opts)) != -1) {
354: ret->no_require_user_presence = r != 1; /* NB. flip */
1.93 djm 355: } else if ((r = opt_flag("verify-required", 1, &opts)) != -1) {
356: ret->require_verify = r == 1;
1.75 djm 357: } else if ((r = opt_flag("pty", 1, &opts)) != -1) {
358: ret->permit_pty_flag = r == 1;
359: } else if ((r = opt_flag("user-rc", 1, &opts)) != -1) {
360: ret->permit_user_rc = r == 1;
361: } else if (opt_match(&opts, "command")) {
362: if (ret->force_command != NULL) {
363: errstr = "multiple \"command\" clauses";
364: goto fail;
365: }
366: ret->force_command = opt_dequote(&opts, &errstr);
367: if (ret->force_command == NULL)
368: goto fail;
369: } else if (opt_match(&opts, "principals")) {
370: if (ret->cert_principals != NULL) {
371: errstr = "multiple \"principals\" clauses";
372: goto fail;
373: }
374: ret->cert_principals = opt_dequote(&opts, &errstr);
375: if (ret->cert_principals == NULL)
376: goto fail;
377: } else if (opt_match(&opts, "from")) {
378: if (ret->required_from_host_keys != NULL) {
379: errstr = "multiple \"from\" clauses";
380: goto fail;
381: }
382: ret->required_from_host_keys = opt_dequote(&opts,
383: &errstr);
384: if (ret->required_from_host_keys == NULL)
385: goto fail;
1.78 djm 386: } else if (opt_match(&opts, "expiry-time")) {
1.77 djm 387: if ((opt = opt_dequote(&opts, &errstr)) == NULL)
388: goto fail;
389: if (parse_absolute_time(opt, &valid_before) != 0 ||
390: valid_before == 0) {
391: free(opt);
392: errstr = "invalid expires time";
393: goto fail;
394: }
395: free(opt);
396: if (ret->valid_before == 0 ||
397: valid_before < ret->valid_before)
398: ret->valid_before = valid_before;
1.75 djm 399: } else if (opt_match(&opts, "environment")) {
1.96 djm 400: if (ret->nenv > SSH_AUTHOPT_ENV_MAX) {
1.75 djm 401: errstr = "too many environment strings";
402: goto fail;
403: }
404: if ((opt = opt_dequote(&opts, &errstr)) == NULL)
405: goto fail;
406: /* env name must be alphanumeric and followed by '=' */
407: if ((tmp = strchr(opt, '=')) == NULL) {
408: free(opt);
409: errstr = "invalid environment string";
410: goto fail;
411: }
1.97 djm 412: if ((cp = strdup(opt)) == NULL) {
413: free(opt);
1.84 djm 414: goto alloc_fail;
1.97 djm 415: }
1.96 djm 416: l = (size_t)(tmp - opt);
417: cp[l] = '\0'; /* truncate at '=' */
1.84 djm 418: if (!valid_env_name(cp)) {
419: free(cp);
420: free(opt);
421: errstr = "invalid environment string";
422: goto fail;
1.75 djm 423: }
1.96 djm 424: /* Check for duplicates; XXX O(n*log(n)) */
425: for (i = 0; i < ret->nenv; i++) {
426: if (strncmp(ret->env[i], cp, l) == 0 &&
427: ret->env[i][l] == '=')
428: break;
429: }
1.84 djm 430: free(cp);
1.96 djm 431: /* First match wins */
432: if (i >= ret->nenv) {
433: /* Append it. */
434: oarray = ret->env;
435: if ((ret->env = recallocarray(ret->env,
436: ret->nenv, ret->nenv + 1,
437: sizeof(*ret->env))) == NULL) {
438: free(opt);
439: /* put it back for cleanup */
440: ret->env = oarray;
441: goto alloc_fail;
442: }
443: ret->env[ret->nenv++] = opt;
1.97 djm 444: opt = NULL; /* transferred */
1.75 djm 445: }
1.97 djm 446: free(opt);
1.75 djm 447: } else if (opt_match(&opts, "permitopen")) {
1.83 djm 448: if (handle_permit(&opts, 0, &ret->permitopen,
1.80 djm 449: &ret->npermitopen, &errstr) != 0)
1.75 djm 450: goto fail;
1.80 djm 451: } else if (opt_match(&opts, "permitlisten")) {
1.83 djm 452: if (handle_permit(&opts, 1, &ret->permitlisten,
1.80 djm 453: &ret->npermitlisten, &errstr) != 0)
1.75 djm 454: goto fail;
455: } else if (opt_match(&opts, "tunnel")) {
456: if ((opt = opt_dequote(&opts, &errstr)) == NULL)
457: goto fail;
458: ret->force_tun_device = a2tun(opt, NULL);
459: free(opt);
460: if (ret->force_tun_device == SSH_TUNID_ERR) {
461: errstr = "invalid tun device";
462: goto fail;
463: }
464: }
465: /*
466: * Skip the comma, and move to the next option
467: * (or break out if there are no more).
468: */
469: if (*opts == '\0' || *opts == ' ' || *opts == '\t')
470: break; /* End of options. */
471: /* Anything other than a comma is an unknown option */
472: if (*opts != ',') {
473: errstr = "unknown key option";
474: goto fail;
475: }
476: opts++;
477: if (*opts == '\0') {
478: errstr = "unexpected end-of-options";
479: goto fail;
480: }
481: }
482:
483: /* success */
484: if (errstrp != NULL)
485: *errstrp = NULL;
486: return ret;
487:
488: alloc_fail:
489: errstr = "memory allocation failed";
490: fail:
491: sshauthopt_free(ret);
492: if (errstrp != NULL)
493: *errstrp = errstr;
494: return NULL;
495: }
496:
497: struct sshauthopt *
498: sshauthopt_from_cert(struct sshkey *k)
499: {
500: struct sshauthopt *ret;
501:
502: if (k == NULL || !sshkey_type_is_cert(k->type) || k->cert == NULL ||
503: k->cert->type != SSH2_CERT_TYPE_USER)
504: return NULL;
505:
506: if ((ret = sshauthopt_new()) == NULL)
507: return NULL;
508:
509: /* Handle options and critical extensions separately */
510: if (cert_option_list(ret, k->cert->critical,
511: OPTIONS_CRITICAL, 1) == -1) {
512: sshauthopt_free(ret);
513: return NULL;
514: }
515: if (cert_option_list(ret, k->cert->extensions,
516: OPTIONS_EXTENSIONS, 0) == -1) {
517: sshauthopt_free(ret);
518: return NULL;
519: }
520: /* success */
521: return ret;
522: }
523:
524: /*
525: * Merges "additional" options to "primary" and returns the result.
526: * NB. Some options from primary have primacy.
527: */
528: struct sshauthopt *
529: sshauthopt_merge(const struct sshauthopt *primary,
530: const struct sshauthopt *additional, const char **errstrp)
531: {
532: struct sshauthopt *ret;
533: const char *errstr = "internal error";
534: const char *tmp;
535:
536: if (errstrp != NULL)
537: *errstrp = NULL;
538:
539: if ((ret = sshauthopt_new()) == NULL)
540: goto alloc_fail;
541:
542: /* cert_authority and cert_principals are cleared in result */
543:
544: /* Prefer access lists from primary. */
545: /* XXX err is both set and mismatch? */
546: tmp = primary->required_from_host_cert;
547: if (tmp == NULL)
548: tmp = additional->required_from_host_cert;
549: if (tmp != NULL && (ret->required_from_host_cert = strdup(tmp)) == NULL)
550: goto alloc_fail;
551: tmp = primary->required_from_host_keys;
552: if (tmp == NULL)
553: tmp = additional->required_from_host_keys;
554: if (tmp != NULL && (ret->required_from_host_keys = strdup(tmp)) == NULL)
555: goto alloc_fail;
556:
1.80 djm 557: /*
558: * force_tun_device, permitopen/permitlisten and environment all
559: * prefer the primary.
560: */
1.75 djm 561: ret->force_tun_device = primary->force_tun_device;
562: if (ret->force_tun_device == -1)
563: ret->force_tun_device = additional->force_tun_device;
564: if (primary->nenv > 0) {
565: if (dup_strings(&ret->env, &ret->nenv,
566: primary->env, primary->nenv) != 0)
567: goto alloc_fail;
568: } else if (additional->nenv) {
569: if (dup_strings(&ret->env, &ret->nenv,
570: additional->env, additional->nenv) != 0)
571: goto alloc_fail;
572: }
573: if (primary->npermitopen > 0) {
574: if (dup_strings(&ret->permitopen, &ret->npermitopen,
575: primary->permitopen, primary->npermitopen) != 0)
576: goto alloc_fail;
577: } else if (additional->npermitopen > 0) {
578: if (dup_strings(&ret->permitopen, &ret->npermitopen,
579: additional->permitopen, additional->npermitopen) != 0)
580: goto alloc_fail;
581: }
582:
1.80 djm 583: if (primary->npermitlisten > 0) {
584: if (dup_strings(&ret->permitlisten, &ret->npermitlisten,
585: primary->permitlisten, primary->npermitlisten) != 0)
586: goto alloc_fail;
587: } else if (additional->npermitlisten > 0) {
588: if (dup_strings(&ret->permitlisten, &ret->npermitlisten,
589: additional->permitlisten, additional->npermitlisten) != 0)
590: goto alloc_fail;
591: }
592:
1.90 djm 593: #define OPTFLAG_AND(x) ret->x = (primary->x == 1) && (additional->x == 1)
1.93 djm 594: #define OPTFLAG_OR(x) ret->x = (primary->x == 1) || (additional->x == 1)
1.90 djm 595: /* Permissive flags are logical-AND (i.e. must be set in both) */
596: OPTFLAG_AND(permit_port_forwarding_flag);
597: OPTFLAG_AND(permit_agent_forwarding_flag);
598: OPTFLAG_AND(permit_x11_forwarding_flag);
599: OPTFLAG_AND(permit_pty_flag);
600: OPTFLAG_AND(permit_user_rc);
601: OPTFLAG_AND(no_require_user_presence);
1.93 djm 602: /* Restrictive flags are logical-OR (i.e. must be set in either) */
603: OPTFLAG_OR(require_verify);
1.90 djm 604: #undef OPTFLAG_AND
1.75 djm 605:
1.77 djm 606: /* Earliest expiry time should win */
607: if (primary->valid_before != 0)
608: ret->valid_before = primary->valid_before;
609: if (additional->valid_before != 0 &&
610: additional->valid_before < ret->valid_before)
611: ret->valid_before = additional->valid_before;
612:
1.75 djm 613: /*
614: * When both multiple forced-command are specified, only
615: * proceed if they are identical, otherwise fail.
616: */
617: if (primary->force_command != NULL &&
618: additional->force_command != NULL) {
619: if (strcmp(primary->force_command,
620: additional->force_command) == 0) {
621: /* ok */
622: ret->force_command = strdup(primary->force_command);
623: if (ret->force_command == NULL)
624: goto alloc_fail;
625: } else {
626: errstr = "forced command options do not match";
627: goto fail;
628: }
629: } else if (primary->force_command != NULL) {
630: if ((ret->force_command = strdup(
631: primary->force_command)) == NULL)
632: goto alloc_fail;
633: } else if (additional->force_command != NULL) {
634: if ((ret->force_command = strdup(
635: additional->force_command)) == NULL)
636: goto alloc_fail;
637: }
638: /* success */
639: if (errstrp != NULL)
640: *errstrp = NULL;
641: return ret;
642:
643: alloc_fail:
644: errstr = "memory allocation failed";
645: fail:
646: if (errstrp != NULL)
647: *errstrp = errstr;
648: sshauthopt_free(ret);
649: return NULL;
650: }
651:
652: /*
653: * Copy options
654: */
655: struct sshauthopt *
656: sshauthopt_copy(const struct sshauthopt *orig)
657: {
658: struct sshauthopt *ret;
659:
660: if ((ret = sshauthopt_new()) == NULL)
661: return NULL;
662:
663: #define OPTSCALAR(x) ret->x = orig->x
664: OPTSCALAR(permit_port_forwarding_flag);
665: OPTSCALAR(permit_agent_forwarding_flag);
666: OPTSCALAR(permit_x11_forwarding_flag);
667: OPTSCALAR(permit_pty_flag);
668: OPTSCALAR(permit_user_rc);
669: OPTSCALAR(restricted);
670: OPTSCALAR(cert_authority);
671: OPTSCALAR(force_tun_device);
1.77 djm 672: OPTSCALAR(valid_before);
1.90 djm 673: OPTSCALAR(no_require_user_presence);
1.93 djm 674: OPTSCALAR(require_verify);
1.75 djm 675: #undef OPTSCALAR
676: #define OPTSTRING(x) \
677: do { \
678: if (orig->x != NULL && (ret->x = strdup(orig->x)) == NULL) { \
679: sshauthopt_free(ret); \
680: return NULL; \
681: } \
682: } while (0)
683: OPTSTRING(cert_principals);
684: OPTSTRING(force_command);
685: OPTSTRING(required_from_host_cert);
686: OPTSTRING(required_from_host_keys);
687: #undef OPTSTRING
688:
689: if (dup_strings(&ret->env, &ret->nenv, orig->env, orig->nenv) != 0 ||
690: dup_strings(&ret->permitopen, &ret->npermitopen,
1.80 djm 691: orig->permitopen, orig->npermitopen) != 0 ||
692: dup_strings(&ret->permitlisten, &ret->npermitlisten,
693: orig->permitlisten, orig->npermitlisten) != 0) {
1.75 djm 694: sshauthopt_free(ret);
695: return NULL;
696: }
697: return ret;
698: }
699:
700: static int
701: serialise_array(struct sshbuf *m, char **a, size_t n)
702: {
703: struct sshbuf *b;
704: size_t i;
1.99 djm 705: int r = SSH_ERR_INTERNAL_ERROR;
1.75 djm 706:
707: if (n > INT_MAX)
708: return SSH_ERR_INTERNAL_ERROR;
709:
710: if ((b = sshbuf_new()) == NULL) {
711: return SSH_ERR_ALLOC_FAIL;
712: }
713: for (i = 0; i < n; i++) {
1.99 djm 714: if ((r = sshbuf_put_cstring(b, a[i])) != 0)
715: goto out;
1.75 djm 716: }
717: if ((r = sshbuf_put_u32(m, n)) != 0 ||
1.99 djm 718: (r = sshbuf_put_stringb(m, b)) != 0)
719: goto out;
1.75 djm 720: /* success */
1.99 djm 721: r = 0;
722: out:
723: sshbuf_free(b);
724: return r;
1.75 djm 725: }
726:
727: static int
728: deserialise_array(struct sshbuf *m, char ***ap, size_t *np)
729: {
730: char **a = NULL;
731: size_t i, n = 0;
732: struct sshbuf *b = NULL;
733: u_int tmp;
734: int r = SSH_ERR_INTERNAL_ERROR;
735:
736: if ((r = sshbuf_get_u32(m, &tmp)) != 0 ||
737: (r = sshbuf_froms(m, &b)) != 0)
738: goto out;
739: if (tmp > INT_MAX) {
740: r = SSH_ERR_INVALID_FORMAT;
741: goto out;
742: }
743: n = tmp;
744: if (n > 0 && (a = calloc(n, sizeof(*a))) == NULL) {
745: r = SSH_ERR_ALLOC_FAIL;
746: goto out;
747: }
748: for (i = 0; i < n; i++) {
749: if ((r = sshbuf_get_cstring(b, &a[i], NULL)) != 0)
750: goto out;
751: }
752: /* success */
753: r = 0;
754: *ap = a;
755: a = NULL;
756: *np = n;
757: n = 0;
758: out:
1.92 markus 759: if (a != NULL) {
760: for (i = 0; i < n; i++)
761: free(a[i]);
762: free(a);
763: }
1.75 djm 764: sshbuf_free(b);
765: return r;
766: }
767:
768: static int
769: serialise_nullable_string(struct sshbuf *m, const char *s)
770: {
771: int r;
772:
773: if ((r = sshbuf_put_u8(m, s == NULL)) != 0 ||
774: (r = sshbuf_put_cstring(m, s)) != 0)
775: return r;
776: return 0;
777: }
778:
779: static int
780: deserialise_nullable_string(struct sshbuf *m, char **sp)
781: {
782: int r;
783: u_char flag;
784:
785: *sp = NULL;
786: if ((r = sshbuf_get_u8(m, &flag)) != 0 ||
787: (r = sshbuf_get_cstring(m, flag ? NULL : sp, NULL)) != 0)
788: return r;
789: return 0;
790: }
791:
792: int
793: sshauthopt_serialise(const struct sshauthopt *opts, struct sshbuf *m,
794: int untrusted)
795: {
796: int r = SSH_ERR_INTERNAL_ERROR;
797:
1.90 djm 798: /* Flag options */
1.75 djm 799: if ((r = sshbuf_put_u8(m, opts->permit_port_forwarding_flag)) != 0 ||
800: (r = sshbuf_put_u8(m, opts->permit_agent_forwarding_flag)) != 0 ||
801: (r = sshbuf_put_u8(m, opts->permit_x11_forwarding_flag)) != 0 ||
802: (r = sshbuf_put_u8(m, opts->permit_pty_flag)) != 0 ||
803: (r = sshbuf_put_u8(m, opts->permit_user_rc)) != 0 ||
804: (r = sshbuf_put_u8(m, opts->restricted)) != 0 ||
1.77 djm 805: (r = sshbuf_put_u8(m, opts->cert_authority)) != 0 ||
1.93 djm 806: (r = sshbuf_put_u8(m, opts->no_require_user_presence)) != 0 ||
807: (r = sshbuf_put_u8(m, opts->require_verify)) != 0)
1.90 djm 808: return r;
809:
810: /* Simple integer options */
811: if ((r = sshbuf_put_u64(m, opts->valid_before)) != 0)
1.75 djm 812: return r;
813:
814: /* tunnel number can be negative to indicate "unset" */
815: if ((r = sshbuf_put_u8(m, opts->force_tun_device == -1)) != 0 ||
816: (r = sshbuf_put_u32(m, (opts->force_tun_device < 0) ?
817: 0 : (u_int)opts->force_tun_device)) != 0)
818: return r;
819:
820: /* String options; these may be NULL */
821: if ((r = serialise_nullable_string(m,
822: untrusted ? "yes" : opts->cert_principals)) != 0 ||
823: (r = serialise_nullable_string(m,
824: untrusted ? "true" : opts->force_command)) != 0 ||
825: (r = serialise_nullable_string(m,
826: untrusted ? NULL : opts->required_from_host_cert)) != 0 ||
827: (r = serialise_nullable_string(m,
1.95 djm 828: untrusted ? NULL : opts->required_from_host_keys)) != 0)
1.75 djm 829: return r;
830:
831: /* Array options */
832: if ((r = serialise_array(m, opts->env,
833: untrusted ? 0 : opts->nenv)) != 0 ||
834: (r = serialise_array(m, opts->permitopen,
1.82 djm 835: untrusted ? 0 : opts->npermitopen)) != 0 ||
1.80 djm 836: (r = serialise_array(m, opts->permitlisten,
837: untrusted ? 0 : opts->npermitlisten)) != 0)
1.75 djm 838: return r;
839:
840: /* success */
841: return 0;
842: }
843:
844: int
845: sshauthopt_deserialise(struct sshbuf *m, struct sshauthopt **optsp)
846: {
847: struct sshauthopt *opts = NULL;
848: int r = SSH_ERR_INTERNAL_ERROR;
849: u_char f;
850: u_int tmp;
851:
852: if ((opts = calloc(1, sizeof(*opts))) == NULL)
853: return SSH_ERR_ALLOC_FAIL;
854:
1.90 djm 855: /* Flag options */
1.75 djm 856: #define OPT_FLAG(x) \
857: do { \
858: if ((r = sshbuf_get_u8(m, &f)) != 0) \
859: goto out; \
860: opts->x = f; \
861: } while (0)
862: OPT_FLAG(permit_port_forwarding_flag);
863: OPT_FLAG(permit_agent_forwarding_flag);
864: OPT_FLAG(permit_x11_forwarding_flag);
865: OPT_FLAG(permit_pty_flag);
866: OPT_FLAG(permit_user_rc);
867: OPT_FLAG(restricted);
868: OPT_FLAG(cert_authority);
1.90 djm 869: OPT_FLAG(no_require_user_presence);
1.93 djm 870: OPT_FLAG(require_verify);
1.75 djm 871: #undef OPT_FLAG
1.77 djm 872:
1.90 djm 873: /* Simple integer options */
1.77 djm 874: if ((r = sshbuf_get_u64(m, &opts->valid_before)) != 0)
875: goto out;
1.75 djm 876:
877: /* tunnel number can be negative to indicate "unset" */
878: if ((r = sshbuf_get_u8(m, &f)) != 0 ||
879: (r = sshbuf_get_u32(m, &tmp)) != 0)
880: goto out;
881: opts->force_tun_device = f ? -1 : (int)tmp;
882:
883: /* String options may be NULL */
884: if ((r = deserialise_nullable_string(m, &opts->cert_principals)) != 0 ||
885: (r = deserialise_nullable_string(m, &opts->force_command)) != 0 ||
886: (r = deserialise_nullable_string(m,
887: &opts->required_from_host_cert)) != 0 ||
888: (r = deserialise_nullable_string(m,
889: &opts->required_from_host_keys)) != 0)
890: goto out;
891:
892: /* Array options */
893: if ((r = deserialise_array(m, &opts->env, &opts->nenv)) != 0 ||
894: (r = deserialise_array(m,
1.80 djm 895: &opts->permitopen, &opts->npermitopen)) != 0 ||
896: (r = deserialise_array(m,
897: &opts->permitlisten, &opts->npermitlisten)) != 0)
1.75 djm 898: goto out;
899:
900: /* success */
901: r = 0;
902: *optsp = opts;
903: opts = NULL;
904: out:
905: sshauthopt_free(opts);
906: return r;
907: }
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