2 * "$Id: auth.c 6779 2007-08-08 19:49:48Z mike $"
4 * Authentication functions for the Common UNIX Printing System (CUPS).
6 * Copyright 2007-2008 by Apple Inc.
7 * Copyright 1997-2007 by Easy Software Products.
9 * This file contains Kerberos support code, copyright 2006 by
12 * These coded instructions, statements, and computer programs are the
13 * property of Apple Inc. and are protected by Federal copyright
14 * law. Distribution and use rights are outlined in the file "LICENSE.txt"
15 * which should have been included with this file. If this file is
16 * file is missing or damaged, see the license at "http://www.cups.org/".
18 * This file is subject to the Apple OS-Developed Software exception.
22 * cupsDoAuthentication() - Authenticate a request.
23 * DEBUG_gss_printf() - Show debug error messages from GSSAPI...
24 * cups_get_gss_creds() - Get CUPS service credentials for authentication.
25 * cups_local_auth() - Get the local authorization certificate if
26 * available/applicable...
30 * Include necessary headers...
40 #if defined(WIN32) || defined(__EMX__)
44 #endif /* WIN32 || __EMX__ */
46 #if HAVE_AUTHORIZATION_H
47 # include <Security/Authorization.h>
48 # ifdef HAVE_SECBASEPRIV_H
49 # include <Security/SecBasePriv.h>
51 extern const char *cssmErrorString(int error
);
52 # endif /* HAVE_SECBASEPRIV_H */
53 #endif /* HAVE_AUTHORIZATION_H */
55 #if defined(SO_PEERCRED) && defined(AF_LOCAL)
57 #endif /* SO_PEERCRED && AF_LOCAL */
66 static void DEBUG_gss_printf(OM_uint32 major_status
, OM_uint32 minor_status
,
69 # define DEBUG_gss_printf(major, minor, message)
71 static gss_name_t
cups_get_gss_creds(http_t
*http
, const char *service_name
);
72 #endif /* HAVE_GSSAPI */
73 static int cups_local_auth(http_t
*http
);
77 * 'cupsDoAuthentication()' - Authenticate a request.
79 * This function should be called in response to a @code HTTP_UNAUTHORIZED@
80 * status, prior to resubmitting your request.
85 int /* O - 0 on success, -1 on error */
86 cupsDoAuthentication(http_t
*http
, /* I - HTTP connection to server */
87 const char *method
,/* I - Request method ("GET", "POST", "PUT") */
89 /* I - Resource path */
91 const char *password
; /* Password string */
92 char prompt
[1024], /* Prompt for user */
93 realm
[HTTP_MAX_VALUE
], /* realm="xyz" string */
94 nonce
[HTTP_MAX_VALUE
]; /* nonce="xyz" string */
95 int localauth
; /* Local authentication result */
96 _cups_globals_t
*cg
; /* Global data */
99 DEBUG_printf(("cupsDoAuthentication(http=%p, method=\"%s\", resource=\"%s\")\n",
100 http
, method
, resource
));
101 DEBUG_printf(("cupsDoAuthentication: digest_tries=%d, userpass=\"%s\"\n",
102 http
->digest_tries
, http
->userpass
));
103 DEBUG_printf(("cupsDoAuthentication: WWW-Authenticate=\"%s\"\n",
104 httpGetField(http
, HTTP_FIELD_WWW_AUTHENTICATE
)));
107 * Clear the current authentication string...
110 httpSetAuthString(http
, NULL
, NULL
);
113 * See if we can do local authentication...
116 if (http
->digest_tries
< 3)
118 if ((localauth
= cups_local_auth(http
)) == 0)
120 DEBUG_printf(("cupsDoAuthentication: authstring=\"%s\"\n",
123 if (http
->status
== HTTP_UNAUTHORIZED
)
124 http
->digest_tries
++;
128 else if (localauth
== -1)
129 return (-1); /* Error or canceled */
133 * Nope, see if we should retry the current username:password...
136 if ((http
->digest_tries
> 1 || !http
->userpass
[0]) &&
137 strncmp(http
->fields
[HTTP_FIELD_WWW_AUTHENTICATE
], "Negotiate", 9))
140 * Nope - get a new password from the user...
145 if (!cg
->lang_default
)
146 cg
->lang_default
= cupsLangDefault();
148 snprintf(prompt
, sizeof(prompt
),
149 _cupsLangString(cg
->lang_default
, _("Password for %s on %s? ")),
151 http
->hostname
[0] == '/' ? "localhost" : http
->hostname
);
153 http
->digest_tries
= strncasecmp(http
->fields
[HTTP_FIELD_WWW_AUTHENTICATE
],
155 http
->userpass
[0] = '\0';
157 if ((password
= cupsGetPassword(prompt
)) == NULL
)
163 snprintf(http
->userpass
, sizeof(http
->userpass
), "%s:%s", cupsUser(),
166 else if (http
->status
== HTTP_UNAUTHORIZED
)
167 http
->digest_tries
++;
170 * Got a password; encode it for the server...
173 if (!strncmp(http
->fields
[HTTP_FIELD_WWW_AUTHENTICATE
], "Negotiate", 9))
177 * Kerberos authentication...
180 OM_uint32 minor_status
, /* Minor status code */
181 major_status
; /* Major status code */
182 gss_buffer_desc output_token
= GSS_C_EMPTY_BUFFER
,
184 input_token
= GSS_C_EMPTY_BUFFER
;
186 char *gss_service_name
;
187 /* GSS service name */
189 const char *authorization
;
190 /* Pointer into Authorization string */
191 # endif /* USE_SPNEGO */
196 * If the weak-linked GSSAPI/Kerberos library is not present, don't try
200 if (gss_init_sec_context
== NULL
)
202 DEBUG_puts("cupsDoAuthentication: Weak-linked GSSAPI/Kerberos framework "
206 # endif /* __APPLE__ */
208 if (http
->status
== HTTP_UNAUTHORIZED
&& http
->digest_tries
>= 3)
210 DEBUG_printf(("cupsDoAuthentication: too many Negotiate tries (%d)\n",
211 http
->digest_tries
));
216 if (http
->gssname
== GSS_C_NO_NAME
)
218 if ((gss_service_name
= getenv("CUPS_GSSSERVICENAME")) == NULL
)
219 gss_service_name
= CUPS_DEFAULT_GSSSERVICENAME
;
221 DEBUG_puts("cupsDoAuthentication: GSS service name set via environment");
223 http
->gssname
= cups_get_gss_creds(http
, gss_service_name
);
226 # ifdef USE_SPNEGO /* We don't implement SPNEGO just yet... */
228 * Find the start of the Kerberos input token...
231 authorization
= httpGetField(http
, HTTP_FIELD_WWW_AUTHENTICATE
);
234 while (*authorization
&& isspace(*authorization
& 255))
240 * Decode the authorization string to get the input token...
243 int len
= strlen(authorization
);
245 input_token
.value
= malloc(len
);
246 input_token
.value
= httpDecode64_2(input_token
.value
, &len
,
248 input_token
.length
= len
;
252 char *ptr
= (char *)input_token
.value
;
255 fputs("input_token=", stdout
);
259 printf("\\%03o", *ptr
& 255);
269 # endif /* USE_SPNEGO */
271 if (http
->gssctx
!= GSS_C_NO_CONTEXT
)
273 major_status
= gss_delete_sec_context(&minor_status
, &http
->gssctx
,
275 http
->gssctx
= GSS_C_NO_CONTEXT
;
278 major_status
= gss_init_sec_context(&minor_status
, GSS_C_NO_CREDENTIAL
,
280 http
->gssname
, http
->gssmech
,
281 GSS_C_DELEG_FLAG
| GSS_C_MUTUAL_FLAG
|
284 GSS_C_NO_CHANNEL_BINDINGS
,
285 &input_token
, &http
->gssmech
,
286 &output_token
, NULL
, NULL
);
288 if (input_token
.value
)
289 free(input_token
.value
);
291 if (GSS_ERROR(major_status
))
294 DEBUG_gss_printf(major_status
, minor_status
,
295 "Unable to initialize security context");
300 if (major_status
== GSS_S_CONTINUE_NEEDED
)
301 DEBUG_gss_printf(major_status
, minor_status
, "Continuation needed!");
303 if (output_token
.length
> 0 && output_token
.length
<= 65536)
306 * Allocate the authorization string since Windows KDCs can have
307 * arbitrarily large credentials...
310 int authsize
= 10 + /* "Negotiate " */
311 output_token
.length
* 4 / 3 + 1 + /* Base64 */
314 httpSetAuthString(http
, NULL
, NULL
);
316 if ((http
->authstring
= malloc(authsize
)) == NULL
)
318 http
->authstring
= http
->_authstring
;
319 authsize
= sizeof(http
->_authstring
);
322 strcpy(http
->authstring
, "Negotiate ");
323 httpEncode64_2(http
->authstring
+ 10, authsize
- 10, output_token
.value
,
324 output_token
.length
);
326 major_status
= gss_release_buffer(&minor_status
, &output_token
);
330 DEBUG_printf(("cupsDoAuthentication: Kerberos credentials too large - "
331 "%d bytes!\n", output_token
.length
));
333 major_status
= gss_release_buffer(&minor_status
, &output_token
);
337 #endif /* HAVE_GSSAPI */
339 else if (strncmp(http
->fields
[HTTP_FIELD_WWW_AUTHENTICATE
], "Digest", 6))
342 * Basic authentication...
345 char encode
[256]; /* Base64 buffer */
348 httpEncode64_2(encode
, sizeof(encode
), http
->userpass
,
349 (int)strlen(http
->userpass
));
350 httpSetAuthString(http
, "Basic", encode
);
355 * Digest authentication...
358 char encode
[33], /* MD5 buffer */
359 digest
[1024]; /* Digest auth data */
362 httpGetSubField(http
, HTTP_FIELD_WWW_AUTHENTICATE
, "realm", realm
);
363 httpGetSubField(http
, HTTP_FIELD_WWW_AUTHENTICATE
, "nonce", nonce
);
365 httpMD5(cupsUser(), realm
, strchr(http
->userpass
, ':') + 1, encode
);
366 httpMD5Final(nonce
, method
, resource
, encode
);
367 snprintf(digest
, sizeof(digest
),
368 "username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", "
369 "response=\"%s\"", cupsUser(), realm
, nonce
, resource
, encode
);
370 httpSetAuthString(http
, "Digest", digest
);
373 DEBUG_printf(("cupsDoAuthentication: authstring=\"%s\"\n", http
->authstring
));
382 * 'DEBUG_gss_printf()' - Show debug error messages from GSSAPI...
386 DEBUG_gss_printf(OM_uint32 major_status
,/* I - Major status code */
387 OM_uint32 minor_status
,/* I - Minor status code */
388 const char *message
) /* I - Prefix for error message */
390 OM_uint32 err_major_status
, /* Major status code for display */
391 err_minor_status
; /* Minor status code for display */
392 OM_uint32 msg_ctx
; /* Message context */
393 gss_buffer_desc major_status_string
= GSS_C_EMPTY_BUFFER
,
394 /* Major status message */
395 minor_status_string
= GSS_C_EMPTY_BUFFER
;
396 /* Minor status message */
400 err_major_status
= gss_display_status(&err_minor_status
,
405 &major_status_string
);
407 if (!GSS_ERROR(err_major_status
))
408 err_major_status
= gss_display_status(&err_minor_status
,
413 &minor_status_string
);
415 printf("%s: %s, %s\n", message
, (char *)major_status_string
.value
,
416 (char *)minor_status_string
.value
);
418 gss_release_buffer(&err_minor_status
, &major_status_string
);
419 gss_release_buffer(&err_minor_status
, &minor_status_string
);
425 * 'cups_get_gss_creds()' - Get CUPS service credentials for authentication.
428 static gss_name_t
/* O - Server name */
430 http_t
*http
, /* I - Connection to server */
431 const char *service_name
) /* I - Service name */
433 gss_buffer_desc token
= GSS_C_EMPTY_BUFFER
;
435 OM_uint32 major_status
, /* Major status code */
436 minor_status
; /* Minor status code */
437 gss_name_t server_name
; /* Server name */
438 char buf
[1024], /* Name buffer */
439 fqdn
[HTTP_MAX_URI
]; /* Server name buffer */
443 * Get the hostname...
446 httpGetHostname(http
, fqdn
, sizeof(fqdn
));
448 if (!strcmp(fqdn
, "localhost"))
449 httpGetHostname(NULL
, fqdn
, sizeof(fqdn
));
452 * Get a server name we can use for authentication purposes...
455 snprintf(buf
, sizeof(buf
), "%s@%s", service_name
, fqdn
);
457 DEBUG_printf(("cups_get_gss_creds: Looking up %s...\n", buf
));
460 token
.length
= strlen(buf
);
461 server_name
= GSS_C_NO_NAME
;
462 major_status
= gss_import_name(&minor_status
, &token
,
463 GSS_C_NT_HOSTBASED_SERVICE
,
466 if (GSS_ERROR(major_status
))
469 DEBUG_gss_printf(major_status
, minor_status
, "gss_import_name() failed");
475 return (server_name
);
477 #endif /* HAVE_GSSAPI */
481 * 'cups_local_auth()' - Get the local authorization certificate if
482 * available/applicable...
485 static int /* O - 0 if available */
486 /* 1 if not available */
488 cups_local_auth(http_t
*http
) /* I - HTTP connection to server */
490 #if defined(WIN32) || defined(__EMX__)
492 * Currently WIN32 and OS-2 do not support the CUPS server...
497 int pid
; /* Current process ID */
498 FILE *fp
; /* Certificate file */
499 char filename
[1024], /* Certificate filename */
500 certificate
[33];/* Certificate string */
501 _cups_globals_t
*cg
= _cupsGlobals(); /* Global data */
502 # if defined(HAVE_AUTHORIZATION_H)
503 OSStatus status
; /* Status */
504 AuthorizationItem auth_right
; /* Authorization right */
505 AuthorizationRights auth_rights
; /* Authorization rights */
506 AuthorizationFlags auth_flags
; /* Authorization flags */
507 AuthorizationExternalForm auth_extrn
; /* Authorization ref external */
508 char auth_key
[1024]; /* Buffer */
509 char buffer
[1024]; /* Buffer */
510 # endif /* HAVE_AUTHORIZATION_H */
513 DEBUG_printf(("cups_local_auth(http=%p) hostaddr=%s, hostname=\"%s\"\n",
514 http
, httpAddrString(http
->hostaddr
, filename
, sizeof(filename
)), http
->hostname
));
517 * See if we are accessing localhost...
520 if (!httpAddrLocalhost(http
->hostaddr
) &&
521 strcasecmp(http
->hostname
, "localhost") != 0)
523 DEBUG_puts("cups_local_auth: Not a local connection!");
527 # if defined(HAVE_AUTHORIZATION_H)
529 * Delete any previous authorization reference...
534 AuthorizationFree(http
->auth_ref
, kAuthorizationFlagDefaults
);
535 http
->auth_ref
= NULL
;
538 if (httpGetSubField2(http
, HTTP_FIELD_WWW_AUTHENTICATE
, "authkey",
539 auth_key
, sizeof(auth_key
)))
541 status
= AuthorizationCreate(NULL
, kAuthorizationEmptyEnvironment
,
542 kAuthorizationFlagDefaults
, &http
->auth_ref
);
543 if (status
!= errAuthorizationSuccess
)
545 DEBUG_printf(("cups_local_auth: AuthorizationCreate() returned %d (%s)\n",
546 (int)status
, cssmErrorString(status
)));
550 auth_right
.name
= auth_key
;
551 auth_right
.valueLength
= 0;
552 auth_right
.value
= NULL
;
553 auth_right
.flags
= 0;
555 auth_rights
.count
= 1;
556 auth_rights
.items
= &auth_right
;
558 auth_flags
= kAuthorizationFlagDefaults
|
559 kAuthorizationFlagPreAuthorize
|
560 kAuthorizationFlagInteractionAllowed
|
561 kAuthorizationFlagExtendRights
;
563 status
= AuthorizationCopyRights(http
->auth_ref
, &auth_rights
,
564 kAuthorizationEmptyEnvironment
,
566 if (status
== errAuthorizationSuccess
)
567 status
= AuthorizationMakeExternalForm(http
->auth_ref
, &auth_extrn
);
569 if (status
== errAuthorizationSuccess
)
572 * Set the authorization string and return...
575 httpEncode64_2(buffer
, sizeof(buffer
), (void *)&auth_extrn
,
578 httpSetAuthString(http
, "AuthRef", buffer
);
580 DEBUG_printf(("cups_local_auth: Returning authstring = \"%s\"\n",
584 else if (status
== errAuthorizationCanceled
)
587 DEBUG_printf(("cups_local_auth: AuthorizationCopyRights() returned %d (%s)\n",
588 (int)status
, cssmErrorString(status
)));
591 * Fall through to try certificates...
594 # endif /* HAVE_AUTHORIZATION_H */
597 * Try opening a certificate file for this PID. If that fails,
598 * try the root certificate...
602 snprintf(filename
, sizeof(filename
), "%s/certs/%d", cg
->cups_statedir
, pid
);
603 if ((fp
= fopen(filename
, "r")) == NULL
&& pid
> 0)
605 DEBUG_printf(("cups_local_auth: Unable to open file %s: %s\n",
606 filename
, strerror(errno
)));
610 * If local certificate authentication isn't available for this PID,
611 * check if we need Kerberos authentication...
614 if (!strncmp(http
->fields
[HTTP_FIELD_WWW_AUTHENTICATE
], "Negotiate", 9))
617 * Yes, don't try the root certificate...
622 #endif /* HAVE_GSSAPI */
624 snprintf(filename
, sizeof(filename
), "%s/certs/0", cg
->cups_statedir
);
625 fp
= fopen(filename
, "r");
631 * Read the certificate from the file...
634 fgets(certificate
, sizeof(certificate
), fp
);
638 * Set the authorization string and return...
641 httpSetAuthString(http
, "Local", certificate
);
643 DEBUG_printf(("cups_local_auth: Returning authstring = \"%s\"\n",
649 # if defined(SO_PEERCRED) && defined(AF_LOCAL)
651 * See if we can authenticate using the peer credentials provided over a
652 * domain socket; if so, specify "PeerCred username" as the authentication
656 if (http
->hostaddr
->addr
.sa_family
== AF_LOCAL
&&
657 !getenv("GATEWAY_INTERFACE")) /* Not via CGI programs... */
660 * Verify that the current cupsUser() matches the current UID...
663 struct passwd
*pwd
; /* Password information */
664 const char *username
; /* Current username */
666 username
= cupsUser();
668 if ((pwd
= getpwnam(username
)) != NULL
&& pwd
->pw_uid
== getuid())
670 httpSetAuthString(http
, "PeerCred", username
);
672 DEBUG_printf(("cups_local_auth: Returning authstring = \"%s\"\n",
678 # endif /* SO_PEERCRED && AF_LOCAL */
681 #endif /* WIN32 || __EMX__ */
686 * End of "$Id: auth.c 6779 2007-08-08 19:49:48Z mike $".