1 /*
2 * Authentication functions for CUPS.
3 *
4 * Copyright 2007-2019 by Apple Inc.
5 * Copyright 1997-2007 by Easy Software Products.
6 *
7 * This file contains Kerberos support code, copyright 2006 by
8 * Jelmer Vernooij.
9 *
10 * Licensed under Apache License v2.0. See the file "LICENSE" for more information.
11 */
12
13 /*
14 * Include necessary headers...
15 */
16
17 #include "cups-private.h"
18 #include "debug-internal.h"
19 #include <fcntl.h>
20 #include <sys/stat.h>
21 #if defined(_WIN32) || defined(__EMX__)
22 # include <io.h>
23 #else
24 # include <unistd.h>
25 #endif /* _WIN32 || __EMX__ */
26
27 #if HAVE_AUTHORIZATION_H
28 # include <Security/Authorization.h>
29 #endif /* HAVE_AUTHORIZATION_H */
30
31 #if defined(SO_PEERCRED) && defined(AF_LOCAL)
32 # include <pwd.h>
33 #endif /* SO_PEERCRED && AF_LOCAL */
34
35
36 /*
37 * Local functions...
38 */
39
40 static const char *cups_auth_find(const char *www_authenticate, const char *scheme);
41 static const char *cups_auth_param(const char *scheme, const char *name, char *value, size_t valsize);
42 static const char *cups_auth_scheme(const char *www_authenticate, char *scheme, size_t schemesize);
43
44 #ifdef HAVE_GSSAPI
45 # define CUPS_GSS_OK 0 /* Successfully set credentials */
46 # define CUPS_GSS_NONE -1 /* No credentials */
47 # define CUPS_GSS_FAIL -2 /* Failed credentials/authentication */
48 # ifdef HAVE_GSS_ACQUIRE_CRED_EX_F
49 # ifdef HAVE_GSS_GSSAPI_SPI_H
50 # include <GSS/gssapi_spi.h>
51 # else
52 # define GSS_AUTH_IDENTITY_TYPE_1 1
53 # define gss_acquire_cred_ex_f __ApplePrivate_gss_acquire_cred_ex_f
54 typedef struct gss_auth_identity /* @private@ */
55 {
56 uint32_t type;
57 uint32_t flags;
58 char *username;
59 char *realm;
60 char *password;
61 gss_buffer_t *credentialsRef;
62 } gss_auth_identity_desc;
63 extern OM_uint32 gss_acquire_cred_ex_f(gss_status_id_t, const gss_name_t,
64 OM_uint32, OM_uint32, const gss_OID,
65 gss_cred_usage_t, gss_auth_identity_t,
66 void *, void (*)(void *, OM_uint32,
67 gss_status_id_t,
68 gss_cred_id_t,
69 gss_OID_set,
70 OM_uint32));
71 # endif /* HAVE_GSS_GSSAPI_SPI_H */
72 # include <dispatch/dispatch.h>
73 typedef struct _cups_gss_acquire_s /* Acquire callback data */
74 {
75 dispatch_semaphore_t sem; /* Synchronization semaphore */
76 OM_uint32 major; /* Returned status code */
77 gss_cred_id_t creds; /* Returned credentials */
78 } _cups_gss_acquire_t;
79
80 static void cups_gss_acquire(void *ctx, OM_uint32 major,
81 gss_status_id_t status,
82 gss_cred_id_t creds, gss_OID_set oids,
83 OM_uint32 time_rec);
84 # endif /* HAVE_GSS_ACQUIRE_CRED_EX_F */
85 static gss_name_t cups_gss_getname(http_t *http, const char *service_name);
86 # ifdef DEBUG
87 static void cups_gss_printf(OM_uint32 major_status, OM_uint32 minor_status,
88 const char *message);
89 # else
90 # define cups_gss_printf(major, minor, message)
91 # endif /* DEBUG */
92 #endif /* HAVE_GSSAPI */
93 static int cups_local_auth(http_t *http);
94
95
96 /*
97 * 'cupsDoAuthentication()' - Authenticate a request.
98 *
99 * This function should be called in response to a @code HTTP_STATUS_UNAUTHORIZED@
100 * status, prior to resubmitting your request.
101 *
102 * @since CUPS 1.1.20/macOS 10.4@
103 */
104
105 int /* O - 0 on success, -1 on error */
cupsDoAuthentication(http_t * http,const char * method,const char * resource)106 cupsDoAuthentication(
107 http_t *http, /* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
108 const char *method, /* I - Request method ("GET", "POST", "PUT") */
109 const char *resource) /* I - Resource path */
110 {
111 const char *password, /* Password string */
112 *www_auth, /* WWW-Authenticate header */
113 *schemedata; /* Scheme-specific data */
114 char scheme[256], /* Scheme name */
115 prompt[1024]; /* Prompt for user */
116 int localauth; /* Local authentication result */
117 _cups_globals_t *cg; /* Global data */
118
119
120 DEBUG_printf(("cupsDoAuthentication(http=%p, method=\"%s\", resource=\"%s\")", (void *)http, method, resource));
121
122 if (!http)
123 http = _cupsConnect();
124
125 if (!http || !method || !resource)
126 return (-1);
127
128 DEBUG_printf(("2cupsDoAuthentication: digest_tries=%d, userpass=\"%s\"",
129 http->digest_tries, http->userpass));
130 DEBUG_printf(("2cupsDoAuthentication: WWW-Authenticate=\"%s\"",
131 httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE)));
132
133 /*
134 * Clear the current authentication string...
135 */
136
137 httpSetAuthString(http, NULL, NULL);
138
139 /*
140 * See if we can do local authentication...
141 */
142
143 if (http->digest_tries < 3)
144 {
145 if ((localauth = cups_local_auth(http)) == 0)
146 {
147 DEBUG_printf(("2cupsDoAuthentication: authstring=\"%s\"",
148 http->authstring));
149
150 if (http->status == HTTP_STATUS_UNAUTHORIZED)
151 http->digest_tries ++;
152
153 return (0);
154 }
155 else if (localauth == -1)
156 {
157 http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;
158 return (-1); /* Error or canceled */
159 }
160 }
161
162 /*
163 * Nope, loop through the authentication schemes to find the first we support.
164 */
165
166 www_auth = httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE);
167
168 for (schemedata = cups_auth_scheme(www_auth, scheme, sizeof(scheme)); schemedata; schemedata = cups_auth_scheme(schemedata + strlen(scheme), scheme, sizeof(scheme)))
169 {
170 /*
171 * Check the scheme name...
172 */
173
174 DEBUG_printf(("2cupsDoAuthentication: Trying scheme \"%s\"...", scheme));
175
176 #ifdef HAVE_GSSAPI
177 if (!_cups_strcasecmp(scheme, "Negotiate"))
178 {
179 /*
180 * Kerberos authentication...
181 */
182
183 int gss_status; /* Auth status */
184
185 if ((gss_status = _cupsSetNegotiateAuthString(http, method, resource)) == CUPS_GSS_FAIL)
186 {
187 DEBUG_puts("1cupsDoAuthentication: Negotiate failed.");
188 http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;
189 return (-1);
190 }
191 else if (gss_status == CUPS_GSS_NONE)
192 {
193 DEBUG_puts("2cupsDoAuthentication: No credentials for Negotiate.");
194 continue;
195 }
196 else
197 {
198 DEBUG_puts("2cupsDoAuthentication: Using Negotiate.");
199 break;
200 }
201 }
202 else
203 #endif /* HAVE_GSSAPI */
204 if (_cups_strcasecmp(scheme, "Basic") && _cups_strcasecmp(scheme, "Digest"))
205 {
206 /*
207 * Other schemes not yet supported...
208 */
209
210 DEBUG_printf(("2cupsDoAuthentication: Scheme \"%s\" not yet supported.", scheme));
211 continue;
212 }
213
214 /*
215 * See if we should retry the current username:password...
216 */
217
218 if ((http->digest_tries > 1 || !http->userpass[0]) && (!_cups_strcasecmp(scheme, "Basic") || (!_cups_strcasecmp(scheme, "Digest"))))
219 {
220 /*
221 * Nope - get a new password from the user...
222 */
223
224 char default_username[HTTP_MAX_VALUE];
225 /* Default username */
226
227 cg = _cupsGlobals();
228
229 if (!cg->lang_default)
230 cg->lang_default = cupsLangDefault();
231
232 if (cups_auth_param(schemedata, "username", default_username, sizeof(default_username)))
233 cupsSetUser(default_username);
234
235 snprintf(prompt, sizeof(prompt), _cupsLangString(cg->lang_default, _("Password for %s on %s? ")), cupsUser(), http->hostname[0] == '/' ? "localhost" : http->hostname);
236
237 http->digest_tries = _cups_strncasecmp(scheme, "Digest", 6) != 0;
238 http->userpass[0] = '\0';
239
240 if ((password = cupsGetPassword2(prompt, http, method, resource)) == NULL)
241 {
242 DEBUG_puts("1cupsDoAuthentication: User canceled password request.");
243 http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;
244 return (-1);
245 }
246
247 snprintf(http->userpass, sizeof(http->userpass), "%s:%s", cupsUser(), password);
248 }
249 else if (http->status == HTTP_STATUS_UNAUTHORIZED)
250 http->digest_tries ++;
251
252 if (http->status == HTTP_STATUS_UNAUTHORIZED && http->digest_tries >= 3)
253 {
254 DEBUG_printf(("1cupsDoAuthentication: Too many authentication tries (%d)", http->digest_tries));
255
256 http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;
257 return (-1);
258 }
259
260 /*
261 * Got a password; encode it for the server...
262 */
263
264 if (!_cups_strcasecmp(scheme, "Basic"))
265 {
266 /*
267 * Basic authentication...
268 */
269
270 char encode[256]; /* Base64 buffer */
271
272 DEBUG_puts("2cupsDoAuthentication: Using Basic.");
273 httpEncode64_2(encode, sizeof(encode), http->userpass, (int)strlen(http->userpass));
274 httpSetAuthString(http, "Basic", encode);
275 break;
276 }
277 else if (!_cups_strcasecmp(scheme, "Digest"))
278 {
279 /*
280 * Digest authentication...
281 */
282
283 char nonce[HTTP_MAX_VALUE]; /* nonce="xyz" string */
284
285 cups_auth_param(schemedata, "algorithm", http->algorithm, sizeof(http->algorithm));
286 cups_auth_param(schemedata, "opaque", http->opaque, sizeof(http->opaque));
287 cups_auth_param(schemedata, "nonce", nonce, sizeof(nonce));
288 cups_auth_param(schemedata, "realm", http->realm, sizeof(http->realm));
289
290 if (_httpSetDigestAuthString(http, nonce, method, resource))
291 {
292 DEBUG_puts("2cupsDoAuthentication: Using Digest.");
293 break;
294 }
295 }
296 }
297
298 if (http->authstring)
299 {
300 DEBUG_printf(("1cupsDoAuthentication: authstring=\"%s\".", http->authstring));
301
302 return (0);
303 }
304 else
305 {
306 DEBUG_puts("1cupsDoAuthentication: No supported schemes.");
307 http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;
308
309 return (-1);
310 }
311 }
312
313
314 #ifdef HAVE_GSSAPI
315 /*
316 * '_cupsSetNegotiateAuthString()' - Set the Kerberos authentication string.
317 */
318
319 int /* O - 0 on success, negative on error */
_cupsSetNegotiateAuthString(http_t * http,const char * method,const char * resource)320 _cupsSetNegotiateAuthString(
321 http_t *http, /* I - Connection to server */
322 const char *method, /* I - Request method ("GET", "POST", "PUT") */
323 const char *resource) /* I - Resource path */
324 {
325 OM_uint32 minor_status, /* Minor status code */
326 major_status; /* Major status code */
327 gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
328 /* Output token */
329
330
331 (void)method;
332 (void)resource;
333
334 # ifdef __APPLE__
335 /*
336 * If the weak-linked GSSAPI/Kerberos library is not present, don't try
337 * to use it...
338 */
339
340 if (&gss_init_sec_context == NULL)
341 {
342 DEBUG_puts("1_cupsSetNegotiateAuthString: Weak-linked GSSAPI/Kerberos "
343 "framework is not present");
344 return (CUPS_GSS_NONE);
345 }
346 # endif /* __APPLE__ */
347
348 if (!strcmp(http->hostname, "localhost") || http->hostname[0] == '/' || isdigit(http->hostname[0] & 255) || !strchr(http->hostname, '.'))
349 {
350 DEBUG_printf(("1_cupsSetNegotiateAuthString: Kerberos not available for host \"%s\".", http->hostname));
351 return (CUPS_GSS_NONE);
352 }
353
354 if (http->gssname == GSS_C_NO_NAME)
355 {
356 http->gssname = cups_gss_getname(http, _cupsGSSServiceName());
357 }
358
359 if (http->gssctx != GSS_C_NO_CONTEXT)
360 {
361 gss_delete_sec_context(&minor_status, &http->gssctx, GSS_C_NO_BUFFER);
362 http->gssctx = GSS_C_NO_CONTEXT;
363 }
364
365 major_status = gss_init_sec_context(&minor_status, GSS_C_NO_CREDENTIAL,
366 &http->gssctx,
367 http->gssname, http->gssmech,
368 GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG,
369 GSS_C_INDEFINITE,
370 GSS_C_NO_CHANNEL_BINDINGS,
371 GSS_C_NO_BUFFER, &http->gssmech,
372 &output_token, NULL, NULL);
373
374 # ifdef HAVE_GSS_ACQUIRE_CRED_EX_F
375 if (major_status == GSS_S_NO_CRED)
376 {
377 /*
378 * Ask the user for credentials...
379 */
380
381 char prompt[1024], /* Prompt for user */
382 userbuf[256]; /* Kerberos username */
383 const char *username, /* Username string */
384 *password; /* Password string */
385 _cups_gss_acquire_t data; /* Callback data */
386 gss_auth_identity_desc identity; /* Kerberos user identity */
387 _cups_globals_t *cg = _cupsGlobals();
388 /* Per-thread global data */
389
390 if (!cg->lang_default)
391 cg->lang_default = cupsLangDefault();
392
393 snprintf(prompt, sizeof(prompt),
394 _cupsLangString(cg->lang_default, _("Password for %s on %s? ")),
395 cupsUser(), http->gsshost);
396
397 if ((password = cupsGetPassword2(prompt, http, method, resource)) == NULL)
398 return (CUPS_GSS_FAIL);
399
400 /*
401 * Try to acquire credentials...
402 */
403
404 username = cupsUser();
405 if (!strchr(username, '@'))
406 {
407 snprintf(userbuf, sizeof(userbuf), "%s@%s", username, http->gsshost);
408 username = userbuf;
409 }
410
411 identity.type = GSS_AUTH_IDENTITY_TYPE_1;
412 identity.flags = 0;
413 identity.username = (char *)username;
414 identity.realm = (char *)"";
415 identity.password = (char *)password;
416 identity.credentialsRef = NULL;
417
418 data.sem = dispatch_semaphore_create(0);
419 data.major = 0;
420 data.creds = NULL;
421
422 if (data.sem)
423 {
424 major_status = gss_acquire_cred_ex_f(NULL, GSS_C_NO_NAME, 0, GSS_C_INDEFINITE, GSS_KRB5_MECHANISM, GSS_C_INITIATE, (gss_auth_identity_t)&identity, &data, cups_gss_acquire);
425
426 if (major_status == GSS_S_COMPLETE)
427 {
428 dispatch_semaphore_wait(data.sem, DISPATCH_TIME_FOREVER);
429 major_status = data.major;
430 }
431
432 dispatch_release(data.sem);
433
434 if (major_status == GSS_S_COMPLETE)
435 {
436 OM_uint32 release_minor; /* Minor status from releasing creds */
437
438 major_status = gss_init_sec_context(&minor_status, data.creds,
439 &http->gssctx,
440 http->gssname, http->gssmech,
441 GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG,
442 GSS_C_INDEFINITE,
443 GSS_C_NO_CHANNEL_BINDINGS,
444 GSS_C_NO_BUFFER, &http->gssmech,
445 &output_token, NULL, NULL);
446 gss_release_cred(&release_minor, &data.creds);
447 }
448 }
449 }
450 # endif /* HAVE_GSS_ACQUIRED_CRED_EX_F */
451
452 if (major_status == GSS_S_NO_CRED)
453 {
454 cups_gss_printf(major_status, minor_status, "_cupsSetNegotiateAuthString: No credentials");
455 return (CUPS_GSS_NONE);
456 }
457 else if (GSS_ERROR(major_status))
458 {
459 cups_gss_printf(major_status, minor_status, "_cupsSetNegotiateAuthString: Unable to initialize security context");
460 return (CUPS_GSS_FAIL);
461 }
462
463 # ifdef DEBUG
464 else if (major_status == GSS_S_CONTINUE_NEEDED)
465 cups_gss_printf(major_status, minor_status, "_cupsSetNegotiateAuthString: Continuation needed");
466 # endif /* DEBUG */
467
468 if (output_token.length > 0 && output_token.length <= 65536)
469 {
470 /*
471 * Allocate the authorization string since Windows KDCs can have
472 * arbitrarily large credentials...
473 */
474
475 int authsize = 10 + /* "Negotiate " */
476 (((int)output_token.length * 4 / 3 + 3) & ~3) + 1;
477 /* Base64 + nul */
478
479 httpSetAuthString(http, NULL, NULL);
480
481 if ((http->authstring = malloc((size_t)authsize)) == NULL)
482 {
483 http->authstring = http->_authstring;
484 authsize = sizeof(http->_authstring);
485 }
486
487 strlcpy(http->authstring, "Negotiate ", (size_t)authsize);
488 httpEncode64_2(http->authstring + 10, authsize - 10, output_token.value,
489 (int)output_token.length);
490
491 gss_release_buffer(&minor_status, &output_token);
492 }
493 else
494 {
495 DEBUG_printf(("1_cupsSetNegotiateAuthString: Kerberos credentials too "
496 "large - %d bytes!", (int)output_token.length));
497 gss_release_buffer(&minor_status, &output_token);
498
499 return (CUPS_GSS_FAIL);
500 }
501
502 return (CUPS_GSS_OK);
503 }
504 #endif /* HAVE_GSSAPI */
505
506
507 /*
508 * 'cups_auth_find()' - Find the named WWW-Authenticate scheme.
509 *
510 * The "www_authenticate" parameter points to the current position in the header.
511 *
512 * Returns @code NULL@ if the auth scheme is not present.
513 */
514
515 static const char * /* O - Start of matching scheme or @code NULL@ if not found */
cups_auth_find(const char * www_authenticate,const char * scheme)516 cups_auth_find(const char *www_authenticate, /* I - Pointer into WWW-Authenticate header */
517 const char *scheme) /* I - Authentication scheme */
518 {
519 size_t schemelen = strlen(scheme); /* Length of scheme */
520
521
522 DEBUG_printf(("8cups_auth_find(www_authenticate=\"%s\", scheme=\"%s\"(%d))", www_authenticate, scheme, (int)schemelen));
523
524 while (*www_authenticate)
525 {
526 /*
527 * Skip leading whitespace and commas...
528 */
529
530 DEBUG_printf(("9cups_auth_find: Before whitespace: \"%s\"", www_authenticate));
531 while (isspace(*www_authenticate & 255) || *www_authenticate == ',')
532 www_authenticate ++;
533 DEBUG_printf(("9cups_auth_find: After whitespace: \"%s\"", www_authenticate));
534
535 /*
536 * See if this is "Scheme" followed by whitespace or the end of the string.
537 */
538
539 if (!strncmp(www_authenticate, scheme, schemelen) && (isspace(www_authenticate[schemelen] & 255) || www_authenticate[schemelen] == ',' || !www_authenticate[schemelen]))
540 {
541 /*
542 * Yes, this is the start of the scheme-specific information...
543 */
544
545 DEBUG_printf(("9cups_auth_find: Returning \"%s\".", www_authenticate));
546
547 return (www_authenticate);
548 }
549
550 /*
551 * Skip the scheme name or param="value" string...
552 */
553
554 while (!isspace(*www_authenticate & 255) && *www_authenticate)
555 {
556 if (*www_authenticate == '\"')
557 {
558 /*
559 * Skip quoted value...
560 */
561
562 www_authenticate ++;
563 while (*www_authenticate && *www_authenticate != '\"')
564 www_authenticate ++;
565
566 DEBUG_printf(("9cups_auth_find: After quoted: \"%s\"", www_authenticate));
567 }
568
569 www_authenticate ++;
570 }
571
572 DEBUG_printf(("9cups_auth_find: After skip: \"%s\"", www_authenticate));
573 }
574
575 DEBUG_puts("9cups_auth_find: Returning NULL.");
576
577 return (NULL);
578 }
579
580
581 /*
582 * 'cups_auth_param()' - Copy the value for the named authentication parameter,
583 * if present.
584 */
585
586 static const char * /* O - Parameter value or @code NULL@ if not present */
cups_auth_param(const char * scheme,const char * name,char * value,size_t valsize)587 cups_auth_param(const char *scheme, /* I - Pointer to auth data */
588 const char *name, /* I - Name of parameter */
589 char *value, /* I - Value buffer */
590 size_t valsize) /* I - Size of value buffer */
591 {
592 char *valptr = value, /* Pointer into value buffer */
593 *valend = value + valsize - 1; /* Pointer to end of buffer */
594 size_t namelen = strlen(name); /* Name length */
595 int param; /* Is this a parameter? */
596
597
598 DEBUG_printf(("8cups_auth_param(scheme=\"%s\", name=\"%s\", value=%p, valsize=%d)", scheme, name, (void *)value, (int)valsize));
599
600 while (!isspace(*scheme & 255) && *scheme)
601 scheme ++;
602
603 while (*scheme)
604 {
605 while (isspace(*scheme & 255) || *scheme == ',')
606 scheme ++;
607
608 if (!strncmp(scheme, name, namelen) && scheme[namelen] == '=')
609 {
610 /*
611 * Found the parameter, copy the value...
612 */
613
614 scheme += namelen + 1;
615 if (*scheme == '\"')
616 {
617 scheme ++;
618
619 while (*scheme && *scheme != '\"')
620 {
621 if (valptr < valend)
622 *valptr++ = *scheme;
623
624 scheme ++;
625 }
626 }
627 else
628 {
629 while (*scheme && strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-._~+/=", *scheme))
630 {
631 if (valptr < valend)
632 *valptr++ = *scheme;
633
634 scheme ++;
635 }
636 }
637
638 *valptr = '\0';
639
640 DEBUG_printf(("9cups_auth_param: Returning \"%s\".", value));
641
642 return (value);
643 }
644
645 /*
646 * Skip the param=value string...
647 */
648
649 param = 0;
650
651 while (!isspace(*scheme & 255) && *scheme)
652 {
653 if (*scheme == '=')
654 param = 1;
655 else if (*scheme == '\"')
656 {
657 /*
658 * Skip quoted value...
659 */
660
661 scheme ++;
662 while (*scheme && *scheme != '\"')
663 scheme ++;
664 }
665
666 scheme ++;
667 }
668
669 /*
670 * If this wasn't a parameter, we are at the end of this scheme's
671 * parameters...
672 */
673
674 if (!param)
675 break;
676 }
677
678 *value = '\0';
679
680 DEBUG_puts("9cups_auth_param: Returning NULL.");
681
682 return (NULL);
683 }
684
685
686 /*
687 * 'cups_auth_scheme()' - Get the (next) WWW-Authenticate scheme.
688 *
689 * The "www_authenticate" parameter points to the current position in the header.
690 *
691 * Returns @code NULL@ if there are no (more) auth schemes present.
692 */
693
694 static const char * /* O - Start of scheme or @code NULL@ if not found */
cups_auth_scheme(const char * www_authenticate,char * scheme,size_t schemesize)695 cups_auth_scheme(const char *www_authenticate, /* I - Pointer into WWW-Authenticate header */
696 char *scheme, /* I - Scheme name buffer */
697 size_t schemesize) /* I - Size of buffer */
698 {
699 const char *start; /* Start of scheme data */
700 char *sptr = scheme, /* Pointer into scheme buffer */
701 *send = scheme + schemesize - 1;/* End of scheme buffer */
702 int param; /* Is this a parameter? */
703
704
705 DEBUG_printf(("8cups_auth_scheme(www_authenticate=\"%s\", scheme=%p, schemesize=%d)", www_authenticate, (void *)scheme, (int)schemesize));
706
707 while (*www_authenticate)
708 {
709 /*
710 * Skip leading whitespace and commas...
711 */
712
713 while (isspace(*www_authenticate & 255) || *www_authenticate == ',')
714 www_authenticate ++;
715
716 /*
717 * Parse the scheme name or param="value" string...
718 */
719
720 for (sptr = scheme, start = www_authenticate, param = 0; *www_authenticate && *www_authenticate != ',' && !isspace(*www_authenticate & 255); www_authenticate ++)
721 {
722 if (*www_authenticate == '=')
723 param = 1;
724 else if (!param && sptr < send)
725 *sptr++ = *www_authenticate;
726 else if (*www_authenticate == '\"')
727 {
728 /*
729 * Skip quoted value...
730 */
731
732 www_authenticate ++;
733 while (*www_authenticate && *www_authenticate != '\"')
734 www_authenticate ++;
735 }
736 }
737
738 if (sptr > scheme && !param)
739 {
740 *sptr = '\0';
741
742 DEBUG_printf(("9cups_auth_scheme: Returning \"%s\".", start));
743
744 return (start);
745 }
746 }
747
748 *scheme = '\0';
749
750 DEBUG_puts("9cups_auth_scheme: Returning NULL.");
751
752 return (NULL);
753 }
754
755
756 #ifdef HAVE_GSSAPI
757 # ifdef HAVE_GSS_ACQUIRE_CRED_EX_F
758 /*
759 * 'cups_gss_acquire()' - Kerberos credentials callback.
760 */
761 static void
cups_gss_acquire(void * ctx,OM_uint32 major,gss_status_id_t status,gss_cred_id_t creds,gss_OID_set oids,OM_uint32 time_rec)762 cups_gss_acquire(
763 void *ctx, /* I - Caller context */
764 OM_uint32 major, /* I - Major error code */
765 gss_status_id_t status, /* I - Status (unused) */
766 gss_cred_id_t creds, /* I - Credentials (if any) */
767 gss_OID_set oids, /* I - Mechanism OIDs (unused) */
768 OM_uint32 time_rec) /* I - Timestamp (unused) */
769 {
770 uint32_t min; /* Minor error code */
771 _cups_gss_acquire_t *data; /* Callback data */
772
773
774 (void)status;
775 (void)time_rec;
776
777 data = (_cups_gss_acquire_t *)ctx;
778 data->major = major;
779 data->creds = creds;
780
781 gss_release_oid_set(&min, &oids);
782 dispatch_semaphore_signal(data->sem);
783 }
784 # endif /* HAVE_GSS_ACQUIRE_CRED_EX_F */
785
786
787 /*
788 * 'cups_gss_getname()' - Get CUPS service credentials for authentication.
789 */
790
791 static gss_name_t /* O - Server name */
cups_gss_getname(http_t * http,const char * service_name)792 cups_gss_getname(
793 http_t *http, /* I - Connection to server */
794 const char *service_name) /* I - Service name */
795 {
796 gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
797 /* Service token */
798 OM_uint32 major_status, /* Major status code */
799 minor_status; /* Minor status code */
800 gss_name_t server_name; /* Server name */
801 char buf[1024]; /* Name buffer */
802
803
804 DEBUG_printf(("7cups_gss_getname(http=%p, service_name=\"%s\")", http,
805 service_name));
806
807
808 /*
809 * Get the hostname...
810 */
811
812 if (!http->gsshost[0])
813 {
814 httpGetHostname(http, http->gsshost, sizeof(http->gsshost));
815
816 if (!strcmp(http->gsshost, "localhost"))
817 {
818 if (gethostname(http->gsshost, sizeof(http->gsshost)) < 0)
819 {
820 DEBUG_printf(("1cups_gss_getname: gethostname() failed: %s",
821 strerror(errno)));
822 http->gsshost[0] = '\0';
823 return (NULL);
824 }
825
826 if (!strchr(http->gsshost, '.'))
827 {
828 /*
829 * The hostname is not a FQDN, so look it up...
830 */
831
832 struct hostent *host; /* Host entry to get FQDN */
833
834 if ((host = gethostbyname(http->gsshost)) != NULL && host->h_name)
835 {
836 /*
837 * Use the resolved hostname...
838 */
839
840 strlcpy(http->gsshost, host->h_name, sizeof(http->gsshost));
841 }
842 else
843 {
844 DEBUG_printf(("1cups_gss_getname: gethostbyname(\"%s\") failed.",
845 http->gsshost));
846 http->gsshost[0] = '\0';
847 return (NULL);
848 }
849 }
850 }
851 }
852
853 /*
854 * Get a service name we can use for authentication purposes...
855 */
856
857 snprintf(buf, sizeof(buf), "%s@%s", service_name, http->gsshost);
858
859 DEBUG_printf(("8cups_gss_getname: Looking up \"%s\".", buf));
860
861 token.value = buf;
862 token.length = strlen(buf);
863 server_name = GSS_C_NO_NAME;
864 major_status = gss_import_name(&minor_status, &token,
865 GSS_C_NT_HOSTBASED_SERVICE,
866 &server_name);
867
868 if (GSS_ERROR(major_status))
869 {
870 cups_gss_printf(major_status, minor_status,
871 "cups_gss_getname: gss_import_name() failed");
872 return (NULL);
873 }
874
875 return (server_name);
876 }
877
878
879 # ifdef DEBUG
880 /*
881 * 'cups_gss_printf()' - Show debug error messages from GSSAPI.
882 */
883
884 static void
cups_gss_printf(OM_uint32 major_status,OM_uint32 minor_status,const char * message)885 cups_gss_printf(OM_uint32 major_status,/* I - Major status code */
886 OM_uint32 minor_status,/* I - Minor status code */
887 const char *message) /* I - Prefix for error message */
888 {
889 OM_uint32 err_major_status, /* Major status code for display */
890 err_minor_status; /* Minor status code for display */
891 OM_uint32 msg_ctx; /* Message context */
892 gss_buffer_desc major_status_string = GSS_C_EMPTY_BUFFER,
893 /* Major status message */
894 minor_status_string = GSS_C_EMPTY_BUFFER;
895 /* Minor status message */
896
897
898 msg_ctx = 0;
899 err_major_status = gss_display_status(&err_minor_status,
900 major_status,
901 GSS_C_GSS_CODE,
902 GSS_C_NO_OID,
903 &msg_ctx,
904 &major_status_string);
905
906 if (!GSS_ERROR(err_major_status))
907 gss_display_status(&err_minor_status, minor_status, GSS_C_MECH_CODE,
908 GSS_C_NULL_OID, &msg_ctx, &minor_status_string);
909
910 DEBUG_printf(("1%s: %s, %s", message, (char *)major_status_string.value,
911 (char *)minor_status_string.value));
912
913 gss_release_buffer(&err_minor_status, &major_status_string);
914 gss_release_buffer(&err_minor_status, &minor_status_string);
915 }
916 # endif /* DEBUG */
917 #endif /* HAVE_GSSAPI */
918
919
920 /*
921 * 'cups_local_auth()' - Get the local authorization certificate if
922 * available/applicable.
923 */
924
925 static int /* O - 0 if available */
926 /* 1 if not available */
927 /* -1 error */
cups_local_auth(http_t * http)928 cups_local_auth(http_t *http) /* I - HTTP connection to server */
929 {
930 #if defined(_WIN32) || defined(__EMX__)
931 /*
932 * Currently _WIN32 and OS-2 do not support the CUPS server...
933 */
934
935 return (1);
936 #else
937 int pid; /* Current process ID */
938 FILE *fp; /* Certificate file */
939 char trc[16], /* Try Root Certificate parameter */
940 filename[1024]; /* Certificate filename */
941 const char *www_auth, /* WWW-Authenticate header */
942 *schemedata; /* Data for the named auth scheme */
943 _cups_globals_t *cg = _cupsGlobals(); /* Global data */
944 # if defined(HAVE_AUTHORIZATION_H)
945 OSStatus status; /* Status */
946 AuthorizationItem auth_right; /* Authorization right */
947 AuthorizationRights auth_rights; /* Authorization rights */
948 AuthorizationFlags auth_flags; /* Authorization flags */
949 AuthorizationExternalForm auth_extrn; /* Authorization ref external */
950 char auth_key[1024]; /* Buffer */
951 char buffer[1024]; /* Buffer */
952 # endif /* HAVE_AUTHORIZATION_H */
953
954
955 DEBUG_printf(("7cups_local_auth(http=%p) hostaddr=%s, hostname=\"%s\"", (void *)http, httpAddrString(http->hostaddr, filename, sizeof(filename)), http->hostname));
956
957 /*
958 * See if we are accessing localhost...
959 */
960
961 if (!httpAddrLocalhost(http->hostaddr) && _cups_strcasecmp(http->hostname, "localhost") != 0)
962 {
963 DEBUG_puts("8cups_local_auth: Not a local connection!");
964 return (1);
965 }
966
967 www_auth = httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE);
968
969 # if defined(HAVE_AUTHORIZATION_H)
970 /*
971 * Delete any previous authorization reference...
972 */
973
974 if (http->auth_ref)
975 {
976 AuthorizationFree(http->auth_ref, kAuthorizationFlagDefaults);
977 http->auth_ref = NULL;
978 }
979
980 if (!getenv("GATEWAY_INTERFACE") && (schemedata = cups_auth_find(www_auth, "AuthRef")) != NULL && cups_auth_param(schemedata, "key", auth_key, sizeof(auth_key)))
981 {
982 status = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &http->auth_ref);
983 if (status != errAuthorizationSuccess)
984 {
985 DEBUG_printf(("8cups_local_auth: AuthorizationCreate() returned %d",
986 (int)status));
987 return (-1);
988 }
989
990 auth_right.name = auth_key;
991 auth_right.valueLength = 0;
992 auth_right.value = NULL;
993 auth_right.flags = 0;
994
995 auth_rights.count = 1;
996 auth_rights.items = &auth_right;
997
998 auth_flags = kAuthorizationFlagDefaults |
999 kAuthorizationFlagPreAuthorize |
1000 kAuthorizationFlagInteractionAllowed |
1001 kAuthorizationFlagExtendRights;
1002
1003 status = AuthorizationCopyRights(http->auth_ref, &auth_rights,
1004 kAuthorizationEmptyEnvironment,
1005 auth_flags, NULL);
1006 if (status == errAuthorizationSuccess)
1007 status = AuthorizationMakeExternalForm(http->auth_ref, &auth_extrn);
1008
1009 if (status == errAuthorizationSuccess)
1010 {
1011 /*
1012 * Set the authorization string and return...
1013 */
1014
1015 httpEncode64_2(buffer, sizeof(buffer), (void *)&auth_extrn,
1016 sizeof(auth_extrn));
1017
1018 httpSetAuthString(http, "AuthRef", buffer);
1019
1020 DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"",
1021 http->authstring));
1022 return (0);
1023 }
1024 else if (status == errAuthorizationCanceled)
1025 return (-1);
1026
1027 DEBUG_printf(("9cups_local_auth: AuthorizationCopyRights() returned %d", (int)status));
1028
1029 /*
1030 * Fall through to try certificates...
1031 */
1032 }
1033 # endif /* HAVE_AUTHORIZATION_H */
1034
1035 # ifdef HAVE_GSSAPI
1036 if (cups_auth_find(www_auth, "Negotiate"))
1037 return (1);
1038 # endif /* HAVE_GSSAPI */
1039
1040 # if defined(SO_PEERCRED) && defined(AF_LOCAL)
1041 /*
1042 * See if we can authenticate using the peer credentials provided over a
1043 * domain socket; if so, specify "PeerCred username" as the authentication
1044 * information...
1045 */
1046
1047 if (http->hostaddr->addr.sa_family == AF_LOCAL &&
1048 !getenv("GATEWAY_INTERFACE") && /* Not via CGI programs... */
1049 cups_auth_find(www_auth, "PeerCred"))
1050 {
1051 /*
1052 * Verify that the current cupsUser() matches the current UID...
1053 */
1054
1055 struct passwd *pwd; /* Password information */
1056 const char *username; /* Current username */
1057
1058 username = cupsUser();
1059
1060 if ((pwd = getpwnam(username)) != NULL && pwd->pw_uid == getuid())
1061 {
1062 httpSetAuthString(http, "PeerCred", username);
1063
1064 DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"",
1065 http->authstring));
1066
1067 return (0);
1068 }
1069 }
1070 # endif /* SO_PEERCRED && AF_LOCAL */
1071
1072 if ((schemedata = cups_auth_find(www_auth, "Local")) == NULL)
1073 return (1);
1074
1075 /*
1076 * Try opening a certificate file for this PID. If that fails,
1077 * try the root certificate...
1078 */
1079
1080 pid = getpid();
1081 snprintf(filename, sizeof(filename), "%s/certs/%d", cg->cups_statedir, pid);
1082 if ((fp = fopen(filename, "r")) == NULL && pid > 0)
1083 {
1084 /*
1085 * No certificate for this PID; see if we can get the root certificate...
1086 */
1087
1088 DEBUG_printf(("9cups_local_auth: Unable to open file \"%s\": %s", filename, strerror(errno)));
1089
1090 if (!cups_auth_param(schemedata, "trc", trc, sizeof(trc)))
1091 {
1092 /*
1093 * Scheduler doesn't want us to use the root certificate...
1094 */
1095
1096 return (1);
1097 }
1098
1099 snprintf(filename, sizeof(filename), "%s/certs/0", cg->cups_statedir);
1100 if ((fp = fopen(filename, "r")) == NULL)
1101 DEBUG_printf(("9cups_local_auth: Unable to open file \"%s\": %s", filename, strerror(errno)));
1102 }
1103
1104 if (fp)
1105 {
1106 /*
1107 * Read the certificate from the file...
1108 */
1109
1110 char certificate[33], /* Certificate string */
1111 *certptr; /* Pointer to certificate string */
1112
1113 certptr = fgets(certificate, sizeof(certificate), fp);
1114 fclose(fp);
1115
1116 if (certptr)
1117 {
1118 /*
1119 * Set the authorization string and return...
1120 */
1121
1122 httpSetAuthString(http, "Local", certificate);
1123
1124 DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"",
1125 http->authstring));
1126
1127 return (0);
1128 }
1129 }
1130
1131 return (1);
1132 #endif /* _WIN32 || __EMX__ */
1133 }
1134