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1.94 ! djm 1: /* $OpenBSD: auth-options.c,v 1.93 2020/08/27 01:07:09 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>
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) {
1.94 ! djm 79: error_f("sshbuf_fromb failed");
1.75 djm 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) {
1.94 ! djm 88: error_r(r, "Unable to parse certificate options");
1.75 djm 89: goto out;
90: }
91: debug3("found certificate option \"%.100s\" len %zu",
92: name, sshbuf_len(data));
93: found = 0;
94: if ((which & OPTIONS_EXTENSIONS) != 0) {
1.90 djm 95: if (strcmp(name, "no-touch-required") == 0) {
96: opts->no_require_user_presence = 1;
97: found = 1;
98: } else if (strcmp(name, "permit-X11-forwarding") == 0) {
1.75 djm 99: opts->permit_x11_forwarding_flag = 1;
100: found = 1;
101: } else if (strcmp(name,
102: "permit-agent-forwarding") == 0) {
103: opts->permit_agent_forwarding_flag = 1;
104: found = 1;
105: } else if (strcmp(name,
106: "permit-port-forwarding") == 0) {
107: opts->permit_port_forwarding_flag = 1;
108: found = 1;
109: } else if (strcmp(name, "permit-pty") == 0) {
110: opts->permit_pty_flag = 1;
111: found = 1;
112: } else if (strcmp(name, "permit-user-rc") == 0) {
113: opts->permit_user_rc = 1;
114: found = 1;
115: }
116: }
117: if (!found && (which & OPTIONS_CRITICAL) != 0) {
1.93 djm 118: if (strcmp(name, "verify-required") == 0) {
119: opts->require_verify = 1;
120: found = 1;
121: } else if (strcmp(name, "force-command") == 0) {
1.75 djm 122: if ((r = sshbuf_get_cstring(data, &command,
123: NULL)) != 0) {
1.94 ! djm 124: error_r(r, "Unable to parse \"%s\" "
! 125: "section", name);
1.75 djm 126: goto out;
127: }
128: if (opts->force_command != NULL) {
129: error("Certificate has multiple "
130: "force-command options");
131: free(command);
132: goto out;
133: }
134: opts->force_command = command;
135: found = 1;
1.93 djm 136: } else if (strcmp(name, "source-address") == 0) {
1.75 djm 137: if ((r = sshbuf_get_cstring(data, &allowed,
138: NULL)) != 0) {
1.94 ! djm 139: error_r(r, "Unable to parse \"%s\" "
! 140: "section", name);
1.75 djm 141: goto out;
142: }
143: if (opts->required_from_host_cert != NULL) {
144: error("Certificate has multiple "
145: "source-address options");
146: free(allowed);
147: goto out;
148: }
149: /* Check syntax */
150: if (addr_match_cidr_list(NULL, allowed) == -1) {
151: error("Certificate source-address "
152: "contents invalid");
153: goto out;
154: }
155: opts->required_from_host_cert = allowed;
156: found = 1;
157: }
158: }
159:
160: if (!found) {
161: if (crit) {
162: error("Certificate critical option \"%s\" "
163: "is not supported", name);
164: goto out;
165: } else {
166: logit("Certificate extension \"%s\" "
167: "is not supported", name);
168: }
169: } else if (sshbuf_len(data) != 0) {
170: error("Certificate option \"%s\" corrupt "
171: "(extra data)", name);
172: goto out;
173: }
174: free(name);
175: name = NULL;
176: }
177: /* successfully parsed all options */
178: ret = 0;
179:
180: out:
181: free(name);
182: sshbuf_free(data);
183: sshbuf_free(c);
184: return ret;
185: }
186:
187: struct sshauthopt *
188: sshauthopt_new(void)
189: {
190: struct sshauthopt *ret;
191:
192: if ((ret = calloc(1, sizeof(*ret))) == NULL)
193: return NULL;
194: ret->force_tun_device = -1;
195: return ret;
196: }
197:
198: void
199: sshauthopt_free(struct sshauthopt *opts)
200: {
201: size_t i;
202:
203: if (opts == NULL)
204: return;
205:
206: free(opts->cert_principals);
207: free(opts->force_command);
208: free(opts->required_from_host_cert);
209: free(opts->required_from_host_keys);
210:
211: for (i = 0; i < opts->nenv; i++)
212: free(opts->env[i]);
213: free(opts->env);
214:
215: for (i = 0; i < opts->npermitopen; i++)
216: free(opts->permitopen[i]);
217: free(opts->permitopen);
218:
1.80 djm 219: for (i = 0; i < opts->npermitlisten; i++)
220: free(opts->permitlisten[i]);
221: free(opts->permitlisten);
222:
1.91 jsg 223: freezero(opts, sizeof(*opts));
1.75 djm 224: }
225:
226: struct sshauthopt *
227: sshauthopt_new_with_keys_defaults(void)
228: {
229: struct sshauthopt *ret = NULL;
230:
231: if ((ret = sshauthopt_new()) == NULL)
232: return NULL;
233:
234: /* Defaults for authorized_keys flags */
235: ret->permit_port_forwarding_flag = 1;
236: ret->permit_agent_forwarding_flag = 1;
237: ret->permit_x11_forwarding_flag = 1;
238: ret->permit_pty_flag = 1;
239: ret->permit_user_rc = 1;
240: return ret;
241: }
242:
1.80 djm 243: /*
244: * Parse and record a permitopen/permitlisten directive.
245: * Return 0 on success. Return -1 on failure and sets *errstrp to error reason.
246: */
247: static int
1.83 djm 248: handle_permit(const char **optsp, int allow_bare_port,
249: char ***permitsp, size_t *npermitsp, const char **errstrp)
1.80 djm 250: {
251: char *opt, *tmp, *cp, *host, **permits = *permitsp;
252: size_t npermits = *npermitsp;
253: const char *errstr = "unknown error";
254:
1.86 djm 255: if (npermits > SSH_AUTHOPT_PERMIT_MAX) {
1.80 djm 256: *errstrp = "too many permission directives";
257: return -1;
258: }
1.82 djm 259: if ((opt = opt_dequote(optsp, &errstr)) == NULL) {
1.80 djm 260: return -1;
261: }
1.83 djm 262: if (allow_bare_port && strchr(opt, ':') == NULL) {
263: /*
264: * Allow a bare port number in permitlisten to indicate a
265: * listen_host wildcard.
266: */
1.85 deraadt 267: if (asprintf(&tmp, "*:%s", opt) == -1) {
1.89 dtucker 268: free(opt);
1.83 djm 269: *errstrp = "memory allocation failed";
270: return -1;
271: }
272: free(opt);
273: opt = tmp;
274: }
1.80 djm 275: if ((tmp = strdup(opt)) == NULL) {
276: free(opt);
277: *errstrp = "memory allocation failed";
278: return -1;
279: }
280: cp = tmp;
281: /* validate syntax before recording it. */
282: host = hpdelim(&cp);
283: if (host == NULL || strlen(host) >= NI_MAXHOST) {
284: free(tmp);
285: free(opt);
286: *errstrp = "invalid permission hostname";
287: return -1;
288: }
289: /*
290: * don't want to use permitopen_port to avoid
291: * dependency on channels.[ch] here.
292: */
293: if (cp == NULL ||
294: (strcmp(cp, "*") != 0 && a2port(cp) <= 0)) {
295: free(tmp);
296: free(opt);
297: *errstrp = "invalid permission port";
298: return -1;
299: }
300: /* XXX - add streamlocal support */
301: free(tmp);
302: /* Record it */
303: if ((permits = recallocarray(permits, npermits, npermits + 1,
304: sizeof(*permits))) == NULL) {
305: free(opt);
306: /* NB. don't update *permitsp if alloc fails */
307: *errstrp = "memory allocation failed";
308: return -1;
309: }
310: permits[npermits++] = opt;
311: *permitsp = permits;
312: *npermitsp = npermits;
313: return 0;
314: }
315:
1.75 djm 316: struct sshauthopt *
317: sshauthopt_parse(const char *opts, const char **errstrp)
318: {
1.80 djm 319: char **oarray, *opt, *cp, *tmp;
1.75 djm 320: int r;
321: struct sshauthopt *ret = NULL;
322: const char *errstr = "unknown error";
1.77 djm 323: uint64_t valid_before;
1.75 djm 324:
325: if (errstrp != NULL)
326: *errstrp = NULL;
327: if ((ret = sshauthopt_new_with_keys_defaults()) == NULL)
328: goto alloc_fail;
329:
330: if (opts == NULL)
331: return ret;
332:
333: while (*opts && *opts != ' ' && *opts != '\t') {
334: /* flag options */
335: if ((r = opt_flag("restrict", 0, &opts)) != -1) {
336: ret->restricted = 1;
337: ret->permit_port_forwarding_flag = 0;
338: ret->permit_agent_forwarding_flag = 0;
339: ret->permit_x11_forwarding_flag = 0;
340: ret->permit_pty_flag = 0;
341: ret->permit_user_rc = 0;
342: } else if ((r = opt_flag("cert-authority", 0, &opts)) != -1) {
343: ret->cert_authority = r;
344: } else if ((r = opt_flag("port-forwarding", 1, &opts)) != -1) {
345: ret->permit_port_forwarding_flag = r == 1;
346: } else if ((r = opt_flag("agent-forwarding", 1, &opts)) != -1) {
347: ret->permit_agent_forwarding_flag = r == 1;
348: } else if ((r = opt_flag("x11-forwarding", 1, &opts)) != -1) {
349: ret->permit_x11_forwarding_flag = r == 1;
1.90 djm 350: } else if ((r = opt_flag("touch-required", 1, &opts)) != -1) {
351: ret->no_require_user_presence = r != 1; /* NB. flip */
1.93 djm 352: } else if ((r = opt_flag("verify-required", 1, &opts)) != -1) {
353: ret->require_verify = r == 1;
1.75 djm 354: } else if ((r = opt_flag("pty", 1, &opts)) != -1) {
355: ret->permit_pty_flag = r == 1;
356: } else if ((r = opt_flag("user-rc", 1, &opts)) != -1) {
357: ret->permit_user_rc = r == 1;
358: } else if (opt_match(&opts, "command")) {
359: if (ret->force_command != NULL) {
360: errstr = "multiple \"command\" clauses";
361: goto fail;
362: }
363: ret->force_command = opt_dequote(&opts, &errstr);
364: if (ret->force_command == NULL)
365: goto fail;
366: } else if (opt_match(&opts, "principals")) {
367: if (ret->cert_principals != NULL) {
368: errstr = "multiple \"principals\" clauses";
369: goto fail;
370: }
371: ret->cert_principals = opt_dequote(&opts, &errstr);
372: if (ret->cert_principals == NULL)
373: goto fail;
374: } else if (opt_match(&opts, "from")) {
375: if (ret->required_from_host_keys != NULL) {
376: errstr = "multiple \"from\" clauses";
377: goto fail;
378: }
379: ret->required_from_host_keys = opt_dequote(&opts,
380: &errstr);
381: if (ret->required_from_host_keys == NULL)
382: goto fail;
1.78 djm 383: } else if (opt_match(&opts, "expiry-time")) {
1.77 djm 384: if ((opt = opt_dequote(&opts, &errstr)) == NULL)
385: goto fail;
386: if (parse_absolute_time(opt, &valid_before) != 0 ||
387: valid_before == 0) {
388: free(opt);
389: errstr = "invalid expires time";
390: goto fail;
391: }
392: free(opt);
393: if (ret->valid_before == 0 ||
394: valid_before < ret->valid_before)
395: ret->valid_before = valid_before;
1.75 djm 396: } else if (opt_match(&opts, "environment")) {
397: if (ret->nenv > INT_MAX) {
398: errstr = "too many environment strings";
399: goto fail;
400: }
401: if ((opt = opt_dequote(&opts, &errstr)) == NULL)
402: goto fail;
403: /* env name must be alphanumeric and followed by '=' */
404: if ((tmp = strchr(opt, '=')) == NULL) {
405: free(opt);
406: errstr = "invalid environment string";
407: goto fail;
408: }
1.84 djm 409: if ((cp = strdup(opt)) == NULL)
410: goto alloc_fail;
411: cp[tmp - opt] = '\0'; /* truncate at '=' */
412: if (!valid_env_name(cp)) {
413: free(cp);
414: free(opt);
415: errstr = "invalid environment string";
416: goto fail;
1.75 djm 417: }
1.84 djm 418: free(cp);
1.75 djm 419: /* Append it. */
420: oarray = ret->env;
421: if ((ret->env = recallocarray(ret->env, ret->nenv,
422: ret->nenv + 1, sizeof(*ret->env))) == NULL) {
423: free(opt);
424: ret->env = oarray; /* put it back for cleanup */
425: goto alloc_fail;
426: }
427: ret->env[ret->nenv++] = opt;
428: } else if (opt_match(&opts, "permitopen")) {
1.83 djm 429: if (handle_permit(&opts, 0, &ret->permitopen,
1.80 djm 430: &ret->npermitopen, &errstr) != 0)
1.75 djm 431: goto fail;
1.80 djm 432: } else if (opt_match(&opts, "permitlisten")) {
1.83 djm 433: if (handle_permit(&opts, 1, &ret->permitlisten,
1.80 djm 434: &ret->npermitlisten, &errstr) != 0)
1.75 djm 435: goto fail;
436: } else if (opt_match(&opts, "tunnel")) {
437: if ((opt = opt_dequote(&opts, &errstr)) == NULL)
438: goto fail;
439: ret->force_tun_device = a2tun(opt, NULL);
440: free(opt);
441: if (ret->force_tun_device == SSH_TUNID_ERR) {
442: errstr = "invalid tun device";
443: goto fail;
444: }
445: }
446: /*
447: * Skip the comma, and move to the next option
448: * (or break out if there are no more).
449: */
450: if (*opts == '\0' || *opts == ' ' || *opts == '\t')
451: break; /* End of options. */
452: /* Anything other than a comma is an unknown option */
453: if (*opts != ',') {
454: errstr = "unknown key option";
455: goto fail;
456: }
457: opts++;
458: if (*opts == '\0') {
459: errstr = "unexpected end-of-options";
460: goto fail;
461: }
462: }
463:
464: /* success */
465: if (errstrp != NULL)
466: *errstrp = NULL;
467: return ret;
468:
469: alloc_fail:
470: errstr = "memory allocation failed";
471: fail:
472: sshauthopt_free(ret);
473: if (errstrp != NULL)
474: *errstrp = errstr;
475: return NULL;
476: }
477:
478: struct sshauthopt *
479: sshauthopt_from_cert(struct sshkey *k)
480: {
481: struct sshauthopt *ret;
482:
483: if (k == NULL || !sshkey_type_is_cert(k->type) || k->cert == NULL ||
484: k->cert->type != SSH2_CERT_TYPE_USER)
485: return NULL;
486:
487: if ((ret = sshauthopt_new()) == NULL)
488: return NULL;
489:
490: /* Handle options and critical extensions separately */
491: if (cert_option_list(ret, k->cert->critical,
492: OPTIONS_CRITICAL, 1) == -1) {
493: sshauthopt_free(ret);
494: return NULL;
495: }
496: if (cert_option_list(ret, k->cert->extensions,
497: OPTIONS_EXTENSIONS, 0) == -1) {
498: sshauthopt_free(ret);
499: return NULL;
500: }
501: /* success */
502: return ret;
503: }
504:
505: /*
506: * Merges "additional" options to "primary" and returns the result.
507: * NB. Some options from primary have primacy.
508: */
509: struct sshauthopt *
510: sshauthopt_merge(const struct sshauthopt *primary,
511: const struct sshauthopt *additional, const char **errstrp)
512: {
513: struct sshauthopt *ret;
514: const char *errstr = "internal error";
515: const char *tmp;
516:
517: if (errstrp != NULL)
518: *errstrp = NULL;
519:
520: if ((ret = sshauthopt_new()) == NULL)
521: goto alloc_fail;
522:
523: /* cert_authority and cert_principals are cleared in result */
524:
525: /* Prefer access lists from primary. */
526: /* XXX err is both set and mismatch? */
527: tmp = primary->required_from_host_cert;
528: if (tmp == NULL)
529: tmp = additional->required_from_host_cert;
530: if (tmp != NULL && (ret->required_from_host_cert = strdup(tmp)) == NULL)
531: goto alloc_fail;
532: tmp = primary->required_from_host_keys;
533: if (tmp == NULL)
534: tmp = additional->required_from_host_keys;
535: if (tmp != NULL && (ret->required_from_host_keys = strdup(tmp)) == NULL)
536: goto alloc_fail;
537:
1.80 djm 538: /*
539: * force_tun_device, permitopen/permitlisten and environment all
540: * prefer the primary.
541: */
1.75 djm 542: ret->force_tun_device = primary->force_tun_device;
543: if (ret->force_tun_device == -1)
544: ret->force_tun_device = additional->force_tun_device;
545: if (primary->nenv > 0) {
546: if (dup_strings(&ret->env, &ret->nenv,
547: primary->env, primary->nenv) != 0)
548: goto alloc_fail;
549: } else if (additional->nenv) {
550: if (dup_strings(&ret->env, &ret->nenv,
551: additional->env, additional->nenv) != 0)
552: goto alloc_fail;
553: }
554: if (primary->npermitopen > 0) {
555: if (dup_strings(&ret->permitopen, &ret->npermitopen,
556: primary->permitopen, primary->npermitopen) != 0)
557: goto alloc_fail;
558: } else if (additional->npermitopen > 0) {
559: if (dup_strings(&ret->permitopen, &ret->npermitopen,
560: additional->permitopen, additional->npermitopen) != 0)
561: goto alloc_fail;
562: }
563:
1.80 djm 564: if (primary->npermitlisten > 0) {
565: if (dup_strings(&ret->permitlisten, &ret->npermitlisten,
566: primary->permitlisten, primary->npermitlisten) != 0)
567: goto alloc_fail;
568: } else if (additional->npermitlisten > 0) {
569: if (dup_strings(&ret->permitlisten, &ret->npermitlisten,
570: additional->permitlisten, additional->npermitlisten) != 0)
571: goto alloc_fail;
572: }
573:
1.90 djm 574: #define OPTFLAG_AND(x) ret->x = (primary->x == 1) && (additional->x == 1)
1.93 djm 575: #define OPTFLAG_OR(x) ret->x = (primary->x == 1) || (additional->x == 1)
1.90 djm 576: /* Permissive flags are logical-AND (i.e. must be set in both) */
577: OPTFLAG_AND(permit_port_forwarding_flag);
578: OPTFLAG_AND(permit_agent_forwarding_flag);
579: OPTFLAG_AND(permit_x11_forwarding_flag);
580: OPTFLAG_AND(permit_pty_flag);
581: OPTFLAG_AND(permit_user_rc);
582: OPTFLAG_AND(no_require_user_presence);
1.93 djm 583: /* Restrictive flags are logical-OR (i.e. must be set in either) */
584: OPTFLAG_OR(require_verify);
1.90 djm 585: #undef OPTFLAG_AND
1.75 djm 586:
1.77 djm 587: /* Earliest expiry time should win */
588: if (primary->valid_before != 0)
589: ret->valid_before = primary->valid_before;
590: if (additional->valid_before != 0 &&
591: additional->valid_before < ret->valid_before)
592: ret->valid_before = additional->valid_before;
593:
1.75 djm 594: /*
595: * When both multiple forced-command are specified, only
596: * proceed if they are identical, otherwise fail.
597: */
598: if (primary->force_command != NULL &&
599: additional->force_command != NULL) {
600: if (strcmp(primary->force_command,
601: additional->force_command) == 0) {
602: /* ok */
603: ret->force_command = strdup(primary->force_command);
604: if (ret->force_command == NULL)
605: goto alloc_fail;
606: } else {
607: errstr = "forced command options do not match";
608: goto fail;
609: }
610: } else if (primary->force_command != NULL) {
611: if ((ret->force_command = strdup(
612: primary->force_command)) == NULL)
613: goto alloc_fail;
614: } else if (additional->force_command != NULL) {
615: if ((ret->force_command = strdup(
616: additional->force_command)) == NULL)
617: goto alloc_fail;
618: }
619: /* success */
620: if (errstrp != NULL)
621: *errstrp = NULL;
622: return ret;
623:
624: alloc_fail:
625: errstr = "memory allocation failed";
626: fail:
627: if (errstrp != NULL)
628: *errstrp = errstr;
629: sshauthopt_free(ret);
630: return NULL;
631: }
632:
633: /*
634: * Copy options
635: */
636: struct sshauthopt *
637: sshauthopt_copy(const struct sshauthopt *orig)
638: {
639: struct sshauthopt *ret;
640:
641: if ((ret = sshauthopt_new()) == NULL)
642: return NULL;
643:
644: #define OPTSCALAR(x) ret->x = orig->x
645: OPTSCALAR(permit_port_forwarding_flag);
646: OPTSCALAR(permit_agent_forwarding_flag);
647: OPTSCALAR(permit_x11_forwarding_flag);
648: OPTSCALAR(permit_pty_flag);
649: OPTSCALAR(permit_user_rc);
650: OPTSCALAR(restricted);
651: OPTSCALAR(cert_authority);
652: OPTSCALAR(force_tun_device);
1.77 djm 653: OPTSCALAR(valid_before);
1.90 djm 654: OPTSCALAR(no_require_user_presence);
1.93 djm 655: OPTSCALAR(require_verify);
1.75 djm 656: #undef OPTSCALAR
657: #define OPTSTRING(x) \
658: do { \
659: if (orig->x != NULL && (ret->x = strdup(orig->x)) == NULL) { \
660: sshauthopt_free(ret); \
661: return NULL; \
662: } \
663: } while (0)
664: OPTSTRING(cert_principals);
665: OPTSTRING(force_command);
666: OPTSTRING(required_from_host_cert);
667: OPTSTRING(required_from_host_keys);
668: #undef OPTSTRING
669:
670: if (dup_strings(&ret->env, &ret->nenv, orig->env, orig->nenv) != 0 ||
671: dup_strings(&ret->permitopen, &ret->npermitopen,
1.80 djm 672: orig->permitopen, orig->npermitopen) != 0 ||
673: dup_strings(&ret->permitlisten, &ret->npermitlisten,
674: orig->permitlisten, orig->npermitlisten) != 0) {
1.75 djm 675: sshauthopt_free(ret);
676: return NULL;
677: }
678: return ret;
679: }
680:
681: static int
682: serialise_array(struct sshbuf *m, char **a, size_t n)
683: {
684: struct sshbuf *b;
685: size_t i;
686: int r;
687:
688: if (n > INT_MAX)
689: return SSH_ERR_INTERNAL_ERROR;
690:
691: if ((b = sshbuf_new()) == NULL) {
692: return SSH_ERR_ALLOC_FAIL;
693: }
694: for (i = 0; i < n; i++) {
695: if ((r = sshbuf_put_cstring(b, a[i])) != 0) {
696: sshbuf_free(b);
697: return r;
698: }
699: }
700: if ((r = sshbuf_put_u32(m, n)) != 0 ||
701: (r = sshbuf_put_stringb(m, b)) != 0) {
702: sshbuf_free(b);
703: return r;
704: }
705: /* success */
706: return 0;
707: }
708:
709: static int
710: deserialise_array(struct sshbuf *m, char ***ap, size_t *np)
711: {
712: char **a = NULL;
713: size_t i, n = 0;
714: struct sshbuf *b = NULL;
715: u_int tmp;
716: int r = SSH_ERR_INTERNAL_ERROR;
717:
718: if ((r = sshbuf_get_u32(m, &tmp)) != 0 ||
719: (r = sshbuf_froms(m, &b)) != 0)
720: goto out;
721: if (tmp > INT_MAX) {
722: r = SSH_ERR_INVALID_FORMAT;
723: goto out;
724: }
725: n = tmp;
726: if (n > 0 && (a = calloc(n, sizeof(*a))) == NULL) {
727: r = SSH_ERR_ALLOC_FAIL;
728: goto out;
729: }
730: for (i = 0; i < n; i++) {
731: if ((r = sshbuf_get_cstring(b, &a[i], NULL)) != 0)
732: goto out;
733: }
734: /* success */
735: r = 0;
736: *ap = a;
737: a = NULL;
738: *np = n;
739: n = 0;
740: out:
1.92 markus 741: if (a != NULL) {
742: for (i = 0; i < n; i++)
743: free(a[i]);
744: free(a);
745: }
1.75 djm 746: sshbuf_free(b);
747: return r;
748: }
749:
750: static int
751: serialise_nullable_string(struct sshbuf *m, const char *s)
752: {
753: int r;
754:
755: if ((r = sshbuf_put_u8(m, s == NULL)) != 0 ||
756: (r = sshbuf_put_cstring(m, s)) != 0)
757: return r;
758: return 0;
759: }
760:
761: static int
762: deserialise_nullable_string(struct sshbuf *m, char **sp)
763: {
764: int r;
765: u_char flag;
766:
767: *sp = NULL;
768: if ((r = sshbuf_get_u8(m, &flag)) != 0 ||
769: (r = sshbuf_get_cstring(m, flag ? NULL : sp, NULL)) != 0)
770: return r;
771: return 0;
772: }
773:
774: int
775: sshauthopt_serialise(const struct sshauthopt *opts, struct sshbuf *m,
776: int untrusted)
777: {
778: int r = SSH_ERR_INTERNAL_ERROR;
779:
1.90 djm 780: /* Flag options */
1.75 djm 781: if ((r = sshbuf_put_u8(m, opts->permit_port_forwarding_flag)) != 0 ||
782: (r = sshbuf_put_u8(m, opts->permit_agent_forwarding_flag)) != 0 ||
783: (r = sshbuf_put_u8(m, opts->permit_x11_forwarding_flag)) != 0 ||
784: (r = sshbuf_put_u8(m, opts->permit_pty_flag)) != 0 ||
785: (r = sshbuf_put_u8(m, opts->permit_user_rc)) != 0 ||
786: (r = sshbuf_put_u8(m, opts->restricted)) != 0 ||
1.77 djm 787: (r = sshbuf_put_u8(m, opts->cert_authority)) != 0 ||
1.93 djm 788: (r = sshbuf_put_u8(m, opts->no_require_user_presence)) != 0 ||
789: (r = sshbuf_put_u8(m, opts->require_verify)) != 0)
1.90 djm 790: return r;
791:
792: /* Simple integer options */
793: if ((r = sshbuf_put_u64(m, opts->valid_before)) != 0)
1.75 djm 794: return r;
795:
796: /* tunnel number can be negative to indicate "unset" */
797: if ((r = sshbuf_put_u8(m, opts->force_tun_device == -1)) != 0 ||
798: (r = sshbuf_put_u32(m, (opts->force_tun_device < 0) ?
799: 0 : (u_int)opts->force_tun_device)) != 0)
800: return r;
801:
802: /* String options; these may be NULL */
803: if ((r = serialise_nullable_string(m,
804: untrusted ? "yes" : opts->cert_principals)) != 0 ||
805: (r = serialise_nullable_string(m,
806: untrusted ? "true" : opts->force_command)) != 0 ||
807: (r = serialise_nullable_string(m,
808: untrusted ? NULL : opts->required_from_host_cert)) != 0 ||
809: (r = serialise_nullable_string(m,
810: untrusted ? NULL : opts->required_from_host_keys)) != 0)
811: return r;
812:
813: /* Array options */
814: if ((r = serialise_array(m, opts->env,
815: untrusted ? 0 : opts->nenv)) != 0 ||
816: (r = serialise_array(m, opts->permitopen,
1.82 djm 817: untrusted ? 0 : opts->npermitopen)) != 0 ||
1.80 djm 818: (r = serialise_array(m, opts->permitlisten,
819: untrusted ? 0 : opts->npermitlisten)) != 0)
1.75 djm 820: return r;
821:
822: /* success */
823: return 0;
824: }
825:
826: int
827: sshauthopt_deserialise(struct sshbuf *m, struct sshauthopt **optsp)
828: {
829: struct sshauthopt *opts = NULL;
830: int r = SSH_ERR_INTERNAL_ERROR;
831: u_char f;
832: u_int tmp;
833:
834: if ((opts = calloc(1, sizeof(*opts))) == NULL)
835: return SSH_ERR_ALLOC_FAIL;
836:
1.90 djm 837: /* Flag options */
1.75 djm 838: #define OPT_FLAG(x) \
839: do { \
840: if ((r = sshbuf_get_u8(m, &f)) != 0) \
841: goto out; \
842: opts->x = f; \
843: } while (0)
844: OPT_FLAG(permit_port_forwarding_flag);
845: OPT_FLAG(permit_agent_forwarding_flag);
846: OPT_FLAG(permit_x11_forwarding_flag);
847: OPT_FLAG(permit_pty_flag);
848: OPT_FLAG(permit_user_rc);
849: OPT_FLAG(restricted);
850: OPT_FLAG(cert_authority);
1.90 djm 851: OPT_FLAG(no_require_user_presence);
1.93 djm 852: OPT_FLAG(require_verify);
1.75 djm 853: #undef OPT_FLAG
1.77 djm 854:
1.90 djm 855: /* Simple integer options */
1.77 djm 856: if ((r = sshbuf_get_u64(m, &opts->valid_before)) != 0)
857: goto out;
1.75 djm 858:
859: /* tunnel number can be negative to indicate "unset" */
860: if ((r = sshbuf_get_u8(m, &f)) != 0 ||
861: (r = sshbuf_get_u32(m, &tmp)) != 0)
862: goto out;
863: opts->force_tun_device = f ? -1 : (int)tmp;
864:
865: /* String options may be NULL */
866: if ((r = deserialise_nullable_string(m, &opts->cert_principals)) != 0 ||
867: (r = deserialise_nullable_string(m, &opts->force_command)) != 0 ||
868: (r = deserialise_nullable_string(m,
869: &opts->required_from_host_cert)) != 0 ||
870: (r = deserialise_nullable_string(m,
871: &opts->required_from_host_keys)) != 0)
872: goto out;
873:
874: /* Array options */
875: if ((r = deserialise_array(m, &opts->env, &opts->nenv)) != 0 ||
876: (r = deserialise_array(m,
1.80 djm 877: &opts->permitopen, &opts->npermitopen)) != 0 ||
878: (r = deserialise_array(m,
879: &opts->permitlisten, &opts->npermitlisten)) != 0)
1.75 djm 880: goto out;
881:
882: /* success */
883: r = 0;
884: *optsp = opts;
885: opts = NULL;
886: out:
887: sshauthopt_free(opts);
888: return r;
889: }