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1.92 ! markus 1: /* $OpenBSD: auth-options.c,v 1.91 2020/02/26 13:40:09 jsg 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>
26: #include <stdarg.h>
1.75 djm 27: #include <ctype.h>
28: #include <limits.h>
1.1 markus 29:
30: #include "xmalloc.h"
1.65 markus 31: #include "ssherr.h"
1.11 markus 32: #include "log.h"
1.65 markus 33: #include "sshbuf.h"
1.64 millert 34: #include "misc.h"
1.65 markus 35: #include "sshkey.h"
1.76 djm 36: #include "match.h"
37: #include "ssh2.h"
1.50 djm 38: #include "auth-options.h"
1.75 djm 39:
40: static int
41: dup_strings(char ***dstp, size_t *ndstp, char **src, size_t nsrc)
42: {
43: char **dst;
44: size_t i, j;
45:
46: *dstp = NULL;
47: *ndstp = 0;
48: if (nsrc == 0)
49: return 0;
50:
51: if ((dst = calloc(nsrc, sizeof(*src))) == NULL)
52: return -1;
53: for (i = 0; i < nsrc; i++) {
54: if ((dst[i] = strdup(src[i])) == NULL) {
55: for (j = 0; j < i; j++)
56: free(dst[j]);
57: free(dst);
58: return -1;
59: }
60: }
61: /* success */
62: *dstp = dst;
63: *ndstp = nsrc;
64: return 0;
65: }
66:
67: #define OPTIONS_CRITICAL 1
68: #define OPTIONS_EXTENSIONS 2
69: static int
70: cert_option_list(struct sshauthopt *opts, struct sshbuf *oblob,
71: u_int which, int crit)
72: {
73: char *command, *allowed;
74: char *name = NULL;
75: struct sshbuf *c = NULL, *data = NULL;
76: int r, ret = -1, found;
77:
78: if ((c = sshbuf_fromb(oblob)) == NULL) {
79: error("%s: sshbuf_fromb failed", __func__);
80: goto out;
81: }
82:
83: while (sshbuf_len(c) > 0) {
84: sshbuf_free(data);
85: data = NULL;
86: if ((r = sshbuf_get_cstring(c, &name, NULL)) != 0 ||
87: (r = sshbuf_froms(c, &data)) != 0) {
88: error("Unable to parse certificate options: %s",
89: ssh_err(r));
90: goto out;
91: }
92: debug3("found certificate option \"%.100s\" len %zu",
93: name, sshbuf_len(data));
94: found = 0;
95: if ((which & OPTIONS_EXTENSIONS) != 0) {
1.90 djm 96: if (strcmp(name, "no-touch-required") == 0) {
97: opts->no_require_user_presence = 1;
98: found = 1;
99: } else if (strcmp(name, "permit-X11-forwarding") == 0) {
1.75 djm 100: opts->permit_x11_forwarding_flag = 1;
101: found = 1;
102: } else if (strcmp(name,
103: "permit-agent-forwarding") == 0) {
104: opts->permit_agent_forwarding_flag = 1;
105: found = 1;
106: } else if (strcmp(name,
107: "permit-port-forwarding") == 0) {
108: opts->permit_port_forwarding_flag = 1;
109: found = 1;
110: } else if (strcmp(name, "permit-pty") == 0) {
111: opts->permit_pty_flag = 1;
112: found = 1;
113: } else if (strcmp(name, "permit-user-rc") == 0) {
114: opts->permit_user_rc = 1;
115: found = 1;
116: }
117: }
118: if (!found && (which & OPTIONS_CRITICAL) != 0) {
119: if (strcmp(name, "force-command") == 0) {
120: if ((r = sshbuf_get_cstring(data, &command,
121: NULL)) != 0) {
122: error("Unable to parse \"%s\" "
123: "section: %s", name, ssh_err(r));
124: goto out;
125: }
126: if (opts->force_command != NULL) {
127: error("Certificate has multiple "
128: "force-command options");
129: free(command);
130: goto out;
131: }
132: opts->force_command = command;
133: found = 1;
134: }
135: if (strcmp(name, "source-address") == 0) {
136: if ((r = sshbuf_get_cstring(data, &allowed,
137: NULL)) != 0) {
138: error("Unable to parse \"%s\" "
139: "section: %s", name, ssh_err(r));
140: goto out;
141: }
142: if (opts->required_from_host_cert != NULL) {
143: error("Certificate has multiple "
144: "source-address options");
145: free(allowed);
146: goto out;
147: }
148: /* Check syntax */
149: if (addr_match_cidr_list(NULL, allowed) == -1) {
150: error("Certificate source-address "
151: "contents invalid");
152: goto out;
153: }
154: opts->required_from_host_cert = allowed;
155: found = 1;
156: }
157: }
158:
159: if (!found) {
160: if (crit) {
161: error("Certificate critical option \"%s\" "
162: "is not supported", name);
163: goto out;
164: } else {
165: logit("Certificate extension \"%s\" "
166: "is not supported", name);
167: }
168: } else if (sshbuf_len(data) != 0) {
169: error("Certificate option \"%s\" corrupt "
170: "(extra data)", name);
171: goto out;
172: }
173: free(name);
174: name = NULL;
175: }
176: /* successfully parsed all options */
177: ret = 0;
178:
179: out:
180: free(name);
181: sshbuf_free(data);
182: sshbuf_free(c);
183: return ret;
184: }
185:
186: struct sshauthopt *
187: sshauthopt_new(void)
188: {
189: struct sshauthopt *ret;
190:
191: if ((ret = calloc(1, sizeof(*ret))) == NULL)
192: return NULL;
193: ret->force_tun_device = -1;
194: return ret;
195: }
196:
197: void
198: sshauthopt_free(struct sshauthopt *opts)
199: {
200: size_t i;
201:
202: if (opts == NULL)
203: return;
204:
205: free(opts->cert_principals);
206: free(opts->force_command);
207: free(opts->required_from_host_cert);
208: free(opts->required_from_host_keys);
209:
210: for (i = 0; i < opts->nenv; i++)
211: free(opts->env[i]);
212: free(opts->env);
213:
214: for (i = 0; i < opts->npermitopen; i++)
215: free(opts->permitopen[i]);
216: free(opts->permitopen);
217:
1.80 djm 218: for (i = 0; i < opts->npermitlisten; i++)
219: free(opts->permitlisten[i]);
220: free(opts->permitlisten);
221:
1.91 jsg 222: freezero(opts, sizeof(*opts));
1.75 djm 223: }
224:
225: struct sshauthopt *
226: sshauthopt_new_with_keys_defaults(void)
227: {
228: struct sshauthopt *ret = NULL;
229:
230: if ((ret = sshauthopt_new()) == NULL)
231: return NULL;
232:
233: /* Defaults for authorized_keys flags */
234: ret->permit_port_forwarding_flag = 1;
235: ret->permit_agent_forwarding_flag = 1;
236: ret->permit_x11_forwarding_flag = 1;
237: ret->permit_pty_flag = 1;
238: ret->permit_user_rc = 1;
239: return ret;
240: }
241:
1.80 djm 242: /*
243: * Parse and record a permitopen/permitlisten directive.
244: * Return 0 on success. Return -1 on failure and sets *errstrp to error reason.
245: */
246: static int
1.83 djm 247: handle_permit(const char **optsp, int allow_bare_port,
248: char ***permitsp, size_t *npermitsp, const char **errstrp)
1.80 djm 249: {
250: char *opt, *tmp, *cp, *host, **permits = *permitsp;
251: size_t npermits = *npermitsp;
252: const char *errstr = "unknown error";
253:
1.86 djm 254: if (npermits > SSH_AUTHOPT_PERMIT_MAX) {
1.80 djm 255: *errstrp = "too many permission directives";
256: return -1;
257: }
1.82 djm 258: if ((opt = opt_dequote(optsp, &errstr)) == NULL) {
1.80 djm 259: return -1;
260: }
1.83 djm 261: if (allow_bare_port && strchr(opt, ':') == NULL) {
262: /*
263: * Allow a bare port number in permitlisten to indicate a
264: * listen_host wildcard.
265: */
1.85 deraadt 266: if (asprintf(&tmp, "*:%s", opt) == -1) {
1.89 dtucker 267: free(opt);
1.83 djm 268: *errstrp = "memory allocation failed";
269: return -1;
270: }
271: free(opt);
272: opt = tmp;
273: }
1.80 djm 274: if ((tmp = strdup(opt)) == NULL) {
275: free(opt);
276: *errstrp = "memory allocation failed";
277: return -1;
278: }
279: cp = tmp;
280: /* validate syntax before recording it. */
281: host = hpdelim(&cp);
282: if (host == NULL || strlen(host) >= NI_MAXHOST) {
283: free(tmp);
284: free(opt);
285: *errstrp = "invalid permission hostname";
286: return -1;
287: }
288: /*
289: * don't want to use permitopen_port to avoid
290: * dependency on channels.[ch] here.
291: */
292: if (cp == NULL ||
293: (strcmp(cp, "*") != 0 && a2port(cp) <= 0)) {
294: free(tmp);
295: free(opt);
296: *errstrp = "invalid permission port";
297: return -1;
298: }
299: /* XXX - add streamlocal support */
300: free(tmp);
301: /* Record it */
302: if ((permits = recallocarray(permits, npermits, npermits + 1,
303: sizeof(*permits))) == NULL) {
304: free(opt);
305: /* NB. don't update *permitsp if alloc fails */
306: *errstrp = "memory allocation failed";
307: return -1;
308: }
309: permits[npermits++] = opt;
310: *permitsp = permits;
311: *npermitsp = npermits;
312: return 0;
313: }
314:
1.75 djm 315: struct sshauthopt *
316: sshauthopt_parse(const char *opts, const char **errstrp)
317: {
1.80 djm 318: char **oarray, *opt, *cp, *tmp;
1.75 djm 319: int r;
320: struct sshauthopt *ret = NULL;
321: const char *errstr = "unknown error";
1.77 djm 322: uint64_t valid_before;
1.75 djm 323:
324: if (errstrp != NULL)
325: *errstrp = NULL;
326: if ((ret = sshauthopt_new_with_keys_defaults()) == NULL)
327: goto alloc_fail;
328:
329: if (opts == NULL)
330: return ret;
331:
332: while (*opts && *opts != ' ' && *opts != '\t') {
333: /* flag options */
334: if ((r = opt_flag("restrict", 0, &opts)) != -1) {
335: ret->restricted = 1;
336: ret->permit_port_forwarding_flag = 0;
337: ret->permit_agent_forwarding_flag = 0;
338: ret->permit_x11_forwarding_flag = 0;
339: ret->permit_pty_flag = 0;
340: ret->permit_user_rc = 0;
341: } else if ((r = opt_flag("cert-authority", 0, &opts)) != -1) {
342: ret->cert_authority = r;
343: } else if ((r = opt_flag("port-forwarding", 1, &opts)) != -1) {
344: ret->permit_port_forwarding_flag = r == 1;
345: } else if ((r = opt_flag("agent-forwarding", 1, &opts)) != -1) {
346: ret->permit_agent_forwarding_flag = r == 1;
347: } else if ((r = opt_flag("x11-forwarding", 1, &opts)) != -1) {
348: ret->permit_x11_forwarding_flag = r == 1;
1.90 djm 349: } else if ((r = opt_flag("touch-required", 1, &opts)) != -1) {
350: ret->no_require_user_presence = r != 1; /* NB. flip */
1.75 djm 351: } else if ((r = opt_flag("pty", 1, &opts)) != -1) {
352: ret->permit_pty_flag = r == 1;
353: } else if ((r = opt_flag("user-rc", 1, &opts)) != -1) {
354: ret->permit_user_rc = r == 1;
355: } else if (opt_match(&opts, "command")) {
356: if (ret->force_command != NULL) {
357: errstr = "multiple \"command\" clauses";
358: goto fail;
359: }
360: ret->force_command = opt_dequote(&opts, &errstr);
361: if (ret->force_command == NULL)
362: goto fail;
363: } else if (opt_match(&opts, "principals")) {
364: if (ret->cert_principals != NULL) {
365: errstr = "multiple \"principals\" clauses";
366: goto fail;
367: }
368: ret->cert_principals = opt_dequote(&opts, &errstr);
369: if (ret->cert_principals == NULL)
370: goto fail;
371: } else if (opt_match(&opts, "from")) {
372: if (ret->required_from_host_keys != NULL) {
373: errstr = "multiple \"from\" clauses";
374: goto fail;
375: }
376: ret->required_from_host_keys = opt_dequote(&opts,
377: &errstr);
378: if (ret->required_from_host_keys == NULL)
379: goto fail;
1.78 djm 380: } else if (opt_match(&opts, "expiry-time")) {
1.77 djm 381: if ((opt = opt_dequote(&opts, &errstr)) == NULL)
382: goto fail;
383: if (parse_absolute_time(opt, &valid_before) != 0 ||
384: valid_before == 0) {
385: free(opt);
386: errstr = "invalid expires time";
387: goto fail;
388: }
389: free(opt);
390: if (ret->valid_before == 0 ||
391: valid_before < ret->valid_before)
392: ret->valid_before = valid_before;
1.75 djm 393: } else if (opt_match(&opts, "environment")) {
394: if (ret->nenv > INT_MAX) {
395: errstr = "too many environment strings";
396: goto fail;
397: }
398: if ((opt = opt_dequote(&opts, &errstr)) == NULL)
399: goto fail;
400: /* env name must be alphanumeric and followed by '=' */
401: if ((tmp = strchr(opt, '=')) == NULL) {
402: free(opt);
403: errstr = "invalid environment string";
404: goto fail;
405: }
1.84 djm 406: if ((cp = strdup(opt)) == NULL)
407: goto alloc_fail;
408: cp[tmp - opt] = '\0'; /* truncate at '=' */
409: if (!valid_env_name(cp)) {
410: free(cp);
411: free(opt);
412: errstr = "invalid environment string";
413: goto fail;
1.75 djm 414: }
1.84 djm 415: free(cp);
1.75 djm 416: /* Append it. */
417: oarray = ret->env;
418: if ((ret->env = recallocarray(ret->env, ret->nenv,
419: ret->nenv + 1, sizeof(*ret->env))) == NULL) {
420: free(opt);
421: ret->env = oarray; /* put it back for cleanup */
422: goto alloc_fail;
423: }
424: ret->env[ret->nenv++] = opt;
425: } else if (opt_match(&opts, "permitopen")) {
1.83 djm 426: if (handle_permit(&opts, 0, &ret->permitopen,
1.80 djm 427: &ret->npermitopen, &errstr) != 0)
1.75 djm 428: goto fail;
1.80 djm 429: } else if (opt_match(&opts, "permitlisten")) {
1.83 djm 430: if (handle_permit(&opts, 1, &ret->permitlisten,
1.80 djm 431: &ret->npermitlisten, &errstr) != 0)
1.75 djm 432: goto fail;
433: } else if (opt_match(&opts, "tunnel")) {
434: if ((opt = opt_dequote(&opts, &errstr)) == NULL)
435: goto fail;
436: ret->force_tun_device = a2tun(opt, NULL);
437: free(opt);
438: if (ret->force_tun_device == SSH_TUNID_ERR) {
439: errstr = "invalid tun device";
440: goto fail;
441: }
442: }
443: /*
444: * Skip the comma, and move to the next option
445: * (or break out if there are no more).
446: */
447: if (*opts == '\0' || *opts == ' ' || *opts == '\t')
448: break; /* End of options. */
449: /* Anything other than a comma is an unknown option */
450: if (*opts != ',') {
451: errstr = "unknown key option";
452: goto fail;
453: }
454: opts++;
455: if (*opts == '\0') {
456: errstr = "unexpected end-of-options";
457: goto fail;
458: }
459: }
460:
461: /* success */
462: if (errstrp != NULL)
463: *errstrp = NULL;
464: return ret;
465:
466: alloc_fail:
467: errstr = "memory allocation failed";
468: fail:
469: sshauthopt_free(ret);
470: if (errstrp != NULL)
471: *errstrp = errstr;
472: return NULL;
473: }
474:
475: struct sshauthopt *
476: sshauthopt_from_cert(struct sshkey *k)
477: {
478: struct sshauthopt *ret;
479:
480: if (k == NULL || !sshkey_type_is_cert(k->type) || k->cert == NULL ||
481: k->cert->type != SSH2_CERT_TYPE_USER)
482: return NULL;
483:
484: if ((ret = sshauthopt_new()) == NULL)
485: return NULL;
486:
487: /* Handle options and critical extensions separately */
488: if (cert_option_list(ret, k->cert->critical,
489: OPTIONS_CRITICAL, 1) == -1) {
490: sshauthopt_free(ret);
491: return NULL;
492: }
493: if (cert_option_list(ret, k->cert->extensions,
494: OPTIONS_EXTENSIONS, 0) == -1) {
495: sshauthopt_free(ret);
496: return NULL;
497: }
498: /* success */
499: return ret;
500: }
501:
502: /*
503: * Merges "additional" options to "primary" and returns the result.
504: * NB. Some options from primary have primacy.
505: */
506: struct sshauthopt *
507: sshauthopt_merge(const struct sshauthopt *primary,
508: const struct sshauthopt *additional, const char **errstrp)
509: {
510: struct sshauthopt *ret;
511: const char *errstr = "internal error";
512: const char *tmp;
513:
514: if (errstrp != NULL)
515: *errstrp = NULL;
516:
517: if ((ret = sshauthopt_new()) == NULL)
518: goto alloc_fail;
519:
520: /* cert_authority and cert_principals are cleared in result */
521:
522: /* Prefer access lists from primary. */
523: /* XXX err is both set and mismatch? */
524: tmp = primary->required_from_host_cert;
525: if (tmp == NULL)
526: tmp = additional->required_from_host_cert;
527: if (tmp != NULL && (ret->required_from_host_cert = strdup(tmp)) == NULL)
528: goto alloc_fail;
529: tmp = primary->required_from_host_keys;
530: if (tmp == NULL)
531: tmp = additional->required_from_host_keys;
532: if (tmp != NULL && (ret->required_from_host_keys = strdup(tmp)) == NULL)
533: goto alloc_fail;
534:
1.80 djm 535: /*
536: * force_tun_device, permitopen/permitlisten and environment all
537: * prefer the primary.
538: */
1.75 djm 539: ret->force_tun_device = primary->force_tun_device;
540: if (ret->force_tun_device == -1)
541: ret->force_tun_device = additional->force_tun_device;
542: if (primary->nenv > 0) {
543: if (dup_strings(&ret->env, &ret->nenv,
544: primary->env, primary->nenv) != 0)
545: goto alloc_fail;
546: } else if (additional->nenv) {
547: if (dup_strings(&ret->env, &ret->nenv,
548: additional->env, additional->nenv) != 0)
549: goto alloc_fail;
550: }
551: if (primary->npermitopen > 0) {
552: if (dup_strings(&ret->permitopen, &ret->npermitopen,
553: primary->permitopen, primary->npermitopen) != 0)
554: goto alloc_fail;
555: } else if (additional->npermitopen > 0) {
556: if (dup_strings(&ret->permitopen, &ret->npermitopen,
557: additional->permitopen, additional->npermitopen) != 0)
558: goto alloc_fail;
559: }
560:
1.80 djm 561: if (primary->npermitlisten > 0) {
562: if (dup_strings(&ret->permitlisten, &ret->npermitlisten,
563: primary->permitlisten, primary->npermitlisten) != 0)
564: goto alloc_fail;
565: } else if (additional->npermitlisten > 0) {
566: if (dup_strings(&ret->permitlisten, &ret->npermitlisten,
567: additional->permitlisten, additional->npermitlisten) != 0)
568: goto alloc_fail;
569: }
570:
1.90 djm 571: #define OPTFLAG_AND(x) ret->x = (primary->x == 1) && (additional->x == 1)
572: /* Permissive flags are logical-AND (i.e. must be set in both) */
573: OPTFLAG_AND(permit_port_forwarding_flag);
574: OPTFLAG_AND(permit_agent_forwarding_flag);
575: OPTFLAG_AND(permit_x11_forwarding_flag);
576: OPTFLAG_AND(permit_pty_flag);
577: OPTFLAG_AND(permit_user_rc);
578: OPTFLAG_AND(no_require_user_presence);
579: #undef OPTFLAG_AND
1.75 djm 580:
1.77 djm 581: /* Earliest expiry time should win */
582: if (primary->valid_before != 0)
583: ret->valid_before = primary->valid_before;
584: if (additional->valid_before != 0 &&
585: additional->valid_before < ret->valid_before)
586: ret->valid_before = additional->valid_before;
587:
1.75 djm 588: /*
589: * When both multiple forced-command are specified, only
590: * proceed if they are identical, otherwise fail.
591: */
592: if (primary->force_command != NULL &&
593: additional->force_command != NULL) {
594: if (strcmp(primary->force_command,
595: additional->force_command) == 0) {
596: /* ok */
597: ret->force_command = strdup(primary->force_command);
598: if (ret->force_command == NULL)
599: goto alloc_fail;
600: } else {
601: errstr = "forced command options do not match";
602: goto fail;
603: }
604: } else if (primary->force_command != NULL) {
605: if ((ret->force_command = strdup(
606: primary->force_command)) == NULL)
607: goto alloc_fail;
608: } else if (additional->force_command != NULL) {
609: if ((ret->force_command = strdup(
610: additional->force_command)) == NULL)
611: goto alloc_fail;
612: }
613: /* success */
614: if (errstrp != NULL)
615: *errstrp = NULL;
616: return ret;
617:
618: alloc_fail:
619: errstr = "memory allocation failed";
620: fail:
621: if (errstrp != NULL)
622: *errstrp = errstr;
623: sshauthopt_free(ret);
624: return NULL;
625: }
626:
627: /*
628: * Copy options
629: */
630: struct sshauthopt *
631: sshauthopt_copy(const struct sshauthopt *orig)
632: {
633: struct sshauthopt *ret;
634:
635: if ((ret = sshauthopt_new()) == NULL)
636: return NULL;
637:
638: #define OPTSCALAR(x) ret->x = orig->x
639: OPTSCALAR(permit_port_forwarding_flag);
640: OPTSCALAR(permit_agent_forwarding_flag);
641: OPTSCALAR(permit_x11_forwarding_flag);
642: OPTSCALAR(permit_pty_flag);
643: OPTSCALAR(permit_user_rc);
644: OPTSCALAR(restricted);
645: OPTSCALAR(cert_authority);
646: OPTSCALAR(force_tun_device);
1.77 djm 647: OPTSCALAR(valid_before);
1.90 djm 648: OPTSCALAR(no_require_user_presence);
1.75 djm 649: #undef OPTSCALAR
650: #define OPTSTRING(x) \
651: do { \
652: if (orig->x != NULL && (ret->x = strdup(orig->x)) == NULL) { \
653: sshauthopt_free(ret); \
654: return NULL; \
655: } \
656: } while (0)
657: OPTSTRING(cert_principals);
658: OPTSTRING(force_command);
659: OPTSTRING(required_from_host_cert);
660: OPTSTRING(required_from_host_keys);
661: #undef OPTSTRING
662:
663: if (dup_strings(&ret->env, &ret->nenv, orig->env, orig->nenv) != 0 ||
664: dup_strings(&ret->permitopen, &ret->npermitopen,
1.80 djm 665: orig->permitopen, orig->npermitopen) != 0 ||
666: dup_strings(&ret->permitlisten, &ret->npermitlisten,
667: orig->permitlisten, orig->npermitlisten) != 0) {
1.75 djm 668: sshauthopt_free(ret);
669: return NULL;
670: }
671: return ret;
672: }
673:
674: static int
675: serialise_array(struct sshbuf *m, char **a, size_t n)
676: {
677: struct sshbuf *b;
678: size_t i;
679: int r;
680:
681: if (n > INT_MAX)
682: return SSH_ERR_INTERNAL_ERROR;
683:
684: if ((b = sshbuf_new()) == NULL) {
685: return SSH_ERR_ALLOC_FAIL;
686: }
687: for (i = 0; i < n; i++) {
688: if ((r = sshbuf_put_cstring(b, a[i])) != 0) {
689: sshbuf_free(b);
690: return r;
691: }
692: }
693: if ((r = sshbuf_put_u32(m, n)) != 0 ||
694: (r = sshbuf_put_stringb(m, b)) != 0) {
695: sshbuf_free(b);
696: return r;
697: }
698: /* success */
699: return 0;
700: }
701:
702: static int
703: deserialise_array(struct sshbuf *m, char ***ap, size_t *np)
704: {
705: char **a = NULL;
706: size_t i, n = 0;
707: struct sshbuf *b = NULL;
708: u_int tmp;
709: int r = SSH_ERR_INTERNAL_ERROR;
710:
711: if ((r = sshbuf_get_u32(m, &tmp)) != 0 ||
712: (r = sshbuf_froms(m, &b)) != 0)
713: goto out;
714: if (tmp > INT_MAX) {
715: r = SSH_ERR_INVALID_FORMAT;
716: goto out;
717: }
718: n = tmp;
719: if (n > 0 && (a = calloc(n, sizeof(*a))) == NULL) {
720: r = SSH_ERR_ALLOC_FAIL;
721: goto out;
722: }
723: for (i = 0; i < n; i++) {
724: if ((r = sshbuf_get_cstring(b, &a[i], NULL)) != 0)
725: goto out;
726: }
727: /* success */
728: r = 0;
729: *ap = a;
730: a = NULL;
731: *np = n;
732: n = 0;
733: out:
1.92 ! markus 734: if (a != NULL) {
! 735: for (i = 0; i < n; i++)
! 736: free(a[i]);
! 737: free(a);
! 738: }
1.75 djm 739: sshbuf_free(b);
740: return r;
741: }
742:
743: static int
744: serialise_nullable_string(struct sshbuf *m, const char *s)
745: {
746: int r;
747:
748: if ((r = sshbuf_put_u8(m, s == NULL)) != 0 ||
749: (r = sshbuf_put_cstring(m, s)) != 0)
750: return r;
751: return 0;
752: }
753:
754: static int
755: deserialise_nullable_string(struct sshbuf *m, char **sp)
756: {
757: int r;
758: u_char flag;
759:
760: *sp = NULL;
761: if ((r = sshbuf_get_u8(m, &flag)) != 0 ||
762: (r = sshbuf_get_cstring(m, flag ? NULL : sp, NULL)) != 0)
763: return r;
764: return 0;
765: }
766:
767: int
768: sshauthopt_serialise(const struct sshauthopt *opts, struct sshbuf *m,
769: int untrusted)
770: {
771: int r = SSH_ERR_INTERNAL_ERROR;
772:
1.90 djm 773: /* Flag options */
1.75 djm 774: if ((r = sshbuf_put_u8(m, opts->permit_port_forwarding_flag)) != 0 ||
775: (r = sshbuf_put_u8(m, opts->permit_agent_forwarding_flag)) != 0 ||
776: (r = sshbuf_put_u8(m, opts->permit_x11_forwarding_flag)) != 0 ||
777: (r = sshbuf_put_u8(m, opts->permit_pty_flag)) != 0 ||
778: (r = sshbuf_put_u8(m, opts->permit_user_rc)) != 0 ||
779: (r = sshbuf_put_u8(m, opts->restricted)) != 0 ||
1.77 djm 780: (r = sshbuf_put_u8(m, opts->cert_authority)) != 0 ||
1.90 djm 781: (r = sshbuf_put_u8(m, opts->no_require_user_presence)) != 0)
782: return r;
783:
784: /* Simple integer options */
785: if ((r = sshbuf_put_u64(m, opts->valid_before)) != 0)
1.75 djm 786: return r;
787:
788: /* tunnel number can be negative to indicate "unset" */
789: if ((r = sshbuf_put_u8(m, opts->force_tun_device == -1)) != 0 ||
790: (r = sshbuf_put_u32(m, (opts->force_tun_device < 0) ?
791: 0 : (u_int)opts->force_tun_device)) != 0)
792: return r;
793:
794: /* String options; these may be NULL */
795: if ((r = serialise_nullable_string(m,
796: untrusted ? "yes" : opts->cert_principals)) != 0 ||
797: (r = serialise_nullable_string(m,
798: untrusted ? "true" : opts->force_command)) != 0 ||
799: (r = serialise_nullable_string(m,
800: untrusted ? NULL : opts->required_from_host_cert)) != 0 ||
801: (r = serialise_nullable_string(m,
802: untrusted ? NULL : opts->required_from_host_keys)) != 0)
803: return r;
804:
805: /* Array options */
806: if ((r = serialise_array(m, opts->env,
807: untrusted ? 0 : opts->nenv)) != 0 ||
808: (r = serialise_array(m, opts->permitopen,
1.82 djm 809: untrusted ? 0 : opts->npermitopen)) != 0 ||
1.80 djm 810: (r = serialise_array(m, opts->permitlisten,
811: untrusted ? 0 : opts->npermitlisten)) != 0)
1.75 djm 812: return r;
813:
814: /* success */
815: return 0;
816: }
817:
818: int
819: sshauthopt_deserialise(struct sshbuf *m, struct sshauthopt **optsp)
820: {
821: struct sshauthopt *opts = NULL;
822: int r = SSH_ERR_INTERNAL_ERROR;
823: u_char f;
824: u_int tmp;
825:
826: if ((opts = calloc(1, sizeof(*opts))) == NULL)
827: return SSH_ERR_ALLOC_FAIL;
828:
1.90 djm 829: /* Flag options */
1.75 djm 830: #define OPT_FLAG(x) \
831: do { \
832: if ((r = sshbuf_get_u8(m, &f)) != 0) \
833: goto out; \
834: opts->x = f; \
835: } while (0)
836: OPT_FLAG(permit_port_forwarding_flag);
837: OPT_FLAG(permit_agent_forwarding_flag);
838: OPT_FLAG(permit_x11_forwarding_flag);
839: OPT_FLAG(permit_pty_flag);
840: OPT_FLAG(permit_user_rc);
841: OPT_FLAG(restricted);
842: OPT_FLAG(cert_authority);
1.90 djm 843: OPT_FLAG(no_require_user_presence);
1.75 djm 844: #undef OPT_FLAG
1.77 djm 845:
1.90 djm 846: /* Simple integer options */
1.77 djm 847: if ((r = sshbuf_get_u64(m, &opts->valid_before)) != 0)
848: goto out;
1.75 djm 849:
850: /* tunnel number can be negative to indicate "unset" */
851: if ((r = sshbuf_get_u8(m, &f)) != 0 ||
852: (r = sshbuf_get_u32(m, &tmp)) != 0)
853: goto out;
854: opts->force_tun_device = f ? -1 : (int)tmp;
855:
856: /* String options may be NULL */
857: if ((r = deserialise_nullable_string(m, &opts->cert_principals)) != 0 ||
858: (r = deserialise_nullable_string(m, &opts->force_command)) != 0 ||
859: (r = deserialise_nullable_string(m,
860: &opts->required_from_host_cert)) != 0 ||
861: (r = deserialise_nullable_string(m,
862: &opts->required_from_host_keys)) != 0)
863: goto out;
864:
865: /* Array options */
866: if ((r = deserialise_array(m, &opts->env, &opts->nenv)) != 0 ||
867: (r = deserialise_array(m,
1.80 djm 868: &opts->permitopen, &opts->npermitopen)) != 0 ||
869: (r = deserialise_array(m,
870: &opts->permitlisten, &opts->npermitlisten)) != 0)
1.75 djm 871: goto out;
872:
873: /* success */
874: r = 0;
875: *optsp = opts;
876: opts = NULL;
877: out:
878: sshauthopt_free(opts);
879: return r;
880: }