/* * Authentication functions for CUPS. * * Copyright 2007-2016 by Apple Inc. * Copyright 1997-2007 by Easy Software Products. * * This file contains Kerberos support code, copyright 2006 by * Jelmer Vernooij. * * These coded instructions, statements, and computer programs are the * property of Apple Inc. and are protected by Federal copyright * law. Distribution and use rights are outlined in the file "LICENSE.txt" * which should have been included with this file. If this file is * missing or damaged, see the license at "http://www.cups.org/". * * This file is subject to the Apple OS-Developed Software exception. */ /* * Include necessary headers... */ #include "cups-private.h" #include <fcntl.h> #include <sys/stat.h> #if defined(WIN32) || defined(__EMX__) # include <io.h> #else # include <unistd.h> #endif /* WIN32 || __EMX__ */ #if HAVE_AUTHORIZATION_H # include <Security/Authorization.h> # ifdef HAVE_SECBASEPRIV_H # include <Security/SecBasePriv.h> # else extern const char *cssmErrorString(int error); # endif /* HAVE_SECBASEPRIV_H */ #endif /* HAVE_AUTHORIZATION_H */ #if defined(SO_PEERCRED) && defined(AF_LOCAL) # include <pwd.h> #endif /* SO_PEERCRED && AF_LOCAL */ /* * Local functions... */ #ifdef HAVE_GSSAPI # ifdef HAVE_GSS_ACQUIRE_CRED_EX_F # ifdef HAVE_GSS_GSSAPI_SPI_H # include <GSS/gssapi_spi.h> # else # define GSS_AUTH_IDENTITY_TYPE_1 1 # define gss_acquire_cred_ex_f __ApplePrivate_gss_acquire_cred_ex_f typedef struct gss_auth_identity { uint32_t type; uint32_t flags; char *username; char *realm; char *password; gss_buffer_t *credentialsRef; } gss_auth_identity_desc; extern OM_uint32 gss_acquire_cred_ex_f(gss_status_id_t, const gss_name_t, OM_uint32, OM_uint32, const gss_OID, gss_cred_usage_t, gss_auth_identity_t, void *, void (*)(void *, OM_uint32, gss_status_id_t, gss_cred_id_t, gss_OID_set, OM_uint32)); # endif /* HAVE_GSS_GSSAPI_SPI_H */ # include <dispatch/dispatch.h> typedef struct _cups_gss_acquire_s /* Acquire callback data */ { dispatch_semaphore_t sem; /* Synchronization semaphore */ OM_uint32 major; /* Returned status code */ gss_cred_id_t creds; /* Returned credentials */ } _cups_gss_acquire_t; 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); # endif /* HAVE_GSS_ACQUIRE_CRED_EX_F */ static gss_name_t cups_gss_getname(http_t *http, const char *service_name); # ifdef DEBUG static void cups_gss_printf(OM_uint32 major_status, OM_uint32 minor_status, const char *message); # else # define cups_gss_printf(major, minor, message) # endif /* DEBUG */ #endif /* HAVE_GSSAPI */ static int cups_local_auth(http_t *http); /* * 'cupsDoAuthentication()' - Authenticate a request. * * This function should be called in response to a @code HTTP_STATUS_UNAUTHORIZED@ * status, prior to resubmitting your request. * * @since CUPS 1.1.20/macOS 10.4@ */ int /* O - 0 on success, -1 on error */ cupsDoAuthentication( http_t *http, /* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */ const char *method, /* I - Request method ("GET", "POST", "PUT") */ const char *resource) /* I - Resource path */ { const char *password, /* Password string */ *www_auth; /* WWW-Authenticate header */ char prompt[1024], /* Prompt for user */ realm[HTTP_MAX_VALUE], /* realm="xyz" string */ nonce[HTTP_MAX_VALUE]; /* nonce="xyz" string */ int localauth; /* Local authentication result */ _cups_globals_t *cg; /* Global data */ DEBUG_printf(("cupsDoAuthentication(http=%p, method=\"%s\", resource=\"%s\")", (void *)http, method, resource)); if (!http) http = _cupsConnect(); if (!http || !method || !resource) return (-1); DEBUG_printf(("2cupsDoAuthentication: digest_tries=%d, userpass=\"%s\"", http->digest_tries, http->userpass)); DEBUG_printf(("2cupsDoAuthentication: WWW-Authenticate=\"%s\"", httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE))); /* * Clear the current authentication string... */ httpSetAuthString(http, NULL, NULL); /* * See if we can do local authentication... */ if (http->digest_tries < 3) { if ((localauth = cups_local_auth(http)) == 0) { DEBUG_printf(("2cupsDoAuthentication: authstring=\"%s\"", http->authstring)); if (http->status == HTTP_STATUS_UNAUTHORIZED) http->digest_tries ++; return (0); } else if (localauth == -1) { http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED; return (-1); /* Error or canceled */ } } /* * Nope, see if we should retry the current username:password... */ www_auth = http->fields[HTTP_FIELD_WWW_AUTHENTICATE]; if ((http->digest_tries > 1 || !http->userpass[0]) && (!_cups_strncasecmp(www_auth, "Basic", 5) || !_cups_strncasecmp(www_auth, "Digest", 6))) { /* * Nope - get a new password from the user... */ char default_username[HTTP_MAX_VALUE]; /* Default username */ cg = _cupsGlobals(); if (!cg->lang_default) cg->lang_default = cupsLangDefault(); if (httpGetSubField(http, HTTP_FIELD_WWW_AUTHENTICATE, "username", default_username)) cupsSetUser(default_username); snprintf(prompt, sizeof(prompt), _cupsLangString(cg->lang_default, _("Password for %s on %s? ")), cupsUser(), http->hostname[0] == '/' ? "localhost" : http->hostname); http->digest_tries = _cups_strncasecmp(www_auth, "Digest", 6) != 0; http->userpass[0] = '\0'; if ((password = cupsGetPassword2(prompt, http, method, resource)) == NULL) { http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED; return (-1); } snprintf(http->userpass, sizeof(http->userpass), "%s:%s", cupsUser(), password); } else if (http->status == HTTP_STATUS_UNAUTHORIZED) http->digest_tries ++; if (http->status == HTTP_STATUS_UNAUTHORIZED && http->digest_tries >= 3) { DEBUG_printf(("1cupsDoAuthentication: Too many authentication tries (%d)", http->digest_tries)); http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED; return (-1); } /* * Got a password; encode it for the server... */ #ifdef HAVE_GSSAPI if (!_cups_strncasecmp(www_auth, "Negotiate", 9)) { /* * Kerberos authentication... */ if (_cupsSetNegotiateAuthString(http, method, resource)) { http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED; return (-1); } } else #endif /* HAVE_GSSAPI */ if (!_cups_strncasecmp(www_auth, "Basic", 5)) { /* * Basic authentication... */ char encode[256]; /* Base64 buffer */ httpEncode64_2(encode, sizeof(encode), http->userpass, (int)strlen(http->userpass)); httpSetAuthString(http, "Basic", encode); } else if (!_cups_strncasecmp(www_auth, "Digest", 6)) { /* * Digest authentication... */ char encode[33], /* MD5 buffer */ digest[1024]; /* Digest auth data */ httpGetSubField(http, HTTP_FIELD_WWW_AUTHENTICATE, "realm", realm); httpGetSubField(http, HTTP_FIELD_WWW_AUTHENTICATE, "nonce", nonce); httpMD5(cupsUser(), realm, strchr(http->userpass, ':') + 1, encode); httpMD5Final(nonce, method, resource, encode); snprintf(digest, sizeof(digest), "username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", " "response=\"%s\"", cupsUser(), realm, nonce, resource, encode); httpSetAuthString(http, "Digest", digest); } else { DEBUG_printf(("1cupsDoAuthentication: Unknown auth type: \"%s\"", www_auth)); http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED; return (-1); } DEBUG_printf(("1cupsDoAuthentication: authstring=\"%s\"", http->authstring)); return (0); } #ifdef HAVE_GSSAPI /* * '_cupsSetNegotiateAuthString()' - Set the Kerberos authentication string. */ int /* O - 0 on success, -1 on error */ _cupsSetNegotiateAuthString( http_t *http, /* I - Connection to server */ const char *method, /* I - Request method ("GET", "POST", "PUT") */ const char *resource) /* I - Resource path */ { OM_uint32 minor_status, /* Minor status code */ major_status; /* Major status code */ gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER; /* Output token */ (void)method; (void)resource; # ifdef __APPLE__ /* * If the weak-linked GSSAPI/Kerberos library is not present, don't try * to use it... */ if (&gss_init_sec_context == NULL) { DEBUG_puts("1_cupsSetNegotiateAuthString: Weak-linked GSSAPI/Kerberos " "framework is not present"); return (-1); } # endif /* __APPLE__ */ if (http->gssname == GSS_C_NO_NAME) { http->gssname = cups_gss_getname(http, _cupsGSSServiceName()); } if (http->gssctx != GSS_C_NO_CONTEXT) { gss_delete_sec_context(&minor_status, &http->gssctx, GSS_C_NO_BUFFER); http->gssctx = GSS_C_NO_CONTEXT; } major_status = gss_init_sec_context(&minor_status, GSS_C_NO_CREDENTIAL, &http->gssctx, http->gssname, http->gssmech, GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG, GSS_C_INDEFINITE, GSS_C_NO_CHANNEL_BINDINGS, GSS_C_NO_BUFFER, &http->gssmech, &output_token, NULL, NULL); #ifdef HAVE_GSS_ACQUIRE_CRED_EX_F if (major_status == GSS_S_NO_CRED) { /* * Ask the user for credentials... */ char prompt[1024], /* Prompt for user */ userbuf[256]; /* Kerberos username */ const char *username, /* Username string */ *password; /* Password string */ _cups_gss_acquire_t data; /* Callback data */ gss_auth_identity_desc identity; /* Kerberos user identity */ _cups_globals_t *cg = _cupsGlobals(); /* Per-thread global data */ if (!cg->lang_default) cg->lang_default = cupsLangDefault(); snprintf(prompt, sizeof(prompt), _cupsLangString(cg->lang_default, _("Password for %s on %s? ")), cupsUser(), http->gsshost); if ((password = cupsGetPassword2(prompt, http, method, resource)) == NULL) return (-1); /* * Try to acquire credentials... */ username = cupsUser(); if (!strchr(username, '@')) { snprintf(userbuf, sizeof(userbuf), "%s@%s", username, http->gsshost); username = userbuf; } identity.type = GSS_AUTH_IDENTITY_TYPE_1; identity.flags = 0; identity.username = (char *)username; identity.realm = (char *)""; identity.password = (char *)password; identity.credentialsRef = NULL; data.sem = dispatch_semaphore_create(0); data.major = 0; data.creds = NULL; if (data.sem) { 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); if (major_status == GSS_S_COMPLETE) { dispatch_semaphore_wait(data.sem, DISPATCH_TIME_FOREVER); major_status = data.major; } dispatch_release(data.sem); if (major_status == GSS_S_COMPLETE) { OM_uint32 release_minor; /* Minor status from releasing creds */ major_status = gss_init_sec_context(&minor_status, data.creds, &http->gssctx, http->gssname, http->gssmech, GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG, GSS_C_INDEFINITE, GSS_C_NO_CHANNEL_BINDINGS, GSS_C_NO_BUFFER, &http->gssmech, &output_token, NULL, NULL); gss_release_cred(&release_minor, &data.creds); } } } #endif /* HAVE_GSS_ACQUIRED_CRED_EX_F */ if (GSS_ERROR(major_status)) { cups_gss_printf(major_status, minor_status, "_cupsSetNegotiateAuthString: Unable to initialize " "security context"); return (-1); } #ifdef DEBUG else if (major_status == GSS_S_CONTINUE_NEEDED) cups_gss_printf(major_status, minor_status, "_cupsSetNegotiateAuthString: Continuation needed!"); #endif /* DEBUG */ if (output_token.length > 0 && output_token.length <= 65536) { /* * Allocate the authorization string since Windows KDCs can have * arbitrarily large credentials... */ int authsize = 10 + /* "Negotiate " */ (int)output_token.length * 4 / 3 + 1 + 1; /* Base64 + nul */ httpSetAuthString(http, NULL, NULL); if ((http->authstring = malloc((size_t)authsize)) == NULL) { http->authstring = http->_authstring; authsize = sizeof(http->_authstring); } strlcpy(http->authstring, "Negotiate ", (size_t)authsize); httpEncode64_2(http->authstring + 10, authsize - 10, output_token.value, (int)output_token.length); gss_release_buffer(&minor_status, &output_token); } else { DEBUG_printf(("1_cupsSetNegotiateAuthString: Kerberos credentials too " "large - %d bytes!", (int)output_token.length)); gss_release_buffer(&minor_status, &output_token); return (-1); } return (0); } # ifdef HAVE_GSS_ACQUIRE_CRED_EX_F /* * 'cups_gss_acquire()' - Kerberos credentials callback. */ static void cups_gss_acquire( void *ctx, /* I - Caller context */ OM_uint32 major, /* I - Major error code */ gss_status_id_t status, /* I - Status (unused) */ gss_cred_id_t creds, /* I - Credentials (if any) */ gss_OID_set oids, /* I - Mechanism OIDs (unused) */ OM_uint32 time_rec) /* I - Timestamp (unused) */ { uint32_t min; /* Minor error code */ _cups_gss_acquire_t *data; /* Callback data */ (void)status; (void)time_rec; data = (_cups_gss_acquire_t *)ctx; data->major = major; data->creds = creds; gss_release_oid_set(&min, &oids); dispatch_semaphore_signal(data->sem); } # endif /* HAVE_GSS_ACQUIRE_CRED_EX_F */ /* * 'cups_gss_getname()' - Get CUPS service credentials for authentication. */ static gss_name_t /* O - Server name */ cups_gss_getname( http_t *http, /* I - Connection to server */ const char *service_name) /* I - Service name */ { gss_buffer_desc token = GSS_C_EMPTY_BUFFER; /* Service token */ OM_uint32 major_status, /* Major status code */ minor_status; /* Minor status code */ gss_name_t server_name; /* Server name */ char buf[1024]; /* Name buffer */ DEBUG_printf(("7cups_gss_getname(http=%p, service_name=\"%s\")", http, service_name)); /* * Get the hostname... */ if (!http->gsshost[0]) { httpGetHostname(http, http->gsshost, sizeof(http->gsshost)); if (!strcmp(http->gsshost, "localhost")) { if (gethostname(http->gsshost, sizeof(http->gsshost)) < 0) { DEBUG_printf(("1cups_gss_getname: gethostname() failed: %s", strerror(errno))); http->gsshost[0] = '\0'; return (NULL); } if (!strchr(http->gsshost, '.')) { /* * The hostname is not a FQDN, so look it up... */ struct hostent *host; /* Host entry to get FQDN */ if ((host = gethostbyname(http->gsshost)) != NULL && host->h_name) { /* * Use the resolved hostname... */ strlcpy(http->gsshost, host->h_name, sizeof(http->gsshost)); } else { DEBUG_printf(("1cups_gss_getname: gethostbyname(\"%s\") failed.", http->gsshost)); http->gsshost[0] = '\0'; return (NULL); } } } } /* * Get a service name we can use for authentication purposes... */ snprintf(buf, sizeof(buf), "%s@%s", service_name, http->gsshost); DEBUG_printf(("8cups_gss_getname: Looking up \"%s\".", buf)); token.value = buf; token.length = strlen(buf); server_name = GSS_C_NO_NAME; major_status = gss_import_name(&minor_status, &token, GSS_C_NT_HOSTBASED_SERVICE, &server_name); if (GSS_ERROR(major_status)) { cups_gss_printf(major_status, minor_status, "cups_gss_getname: gss_import_name() failed"); return (NULL); } return (server_name); } # ifdef DEBUG /* * 'cups_gss_printf()' - Show debug error messages from GSSAPI. */ static void cups_gss_printf(OM_uint32 major_status,/* I - Major status code */ OM_uint32 minor_status,/* I - Minor status code */ const char *message) /* I - Prefix for error message */ { OM_uint32 err_major_status, /* Major status code for display */ err_minor_status; /* Minor status code for display */ OM_uint32 msg_ctx; /* Message context */ gss_buffer_desc major_status_string = GSS_C_EMPTY_BUFFER, /* Major status message */ minor_status_string = GSS_C_EMPTY_BUFFER; /* Minor status message */ msg_ctx = 0; err_major_status = gss_display_status(&err_minor_status, major_status, GSS_C_GSS_CODE, GSS_C_NO_OID, &msg_ctx, &major_status_string); if (!GSS_ERROR(err_major_status)) gss_display_status(&err_minor_status, minor_status, GSS_C_MECH_CODE, GSS_C_NULL_OID, &msg_ctx, &minor_status_string); DEBUG_printf(("1%s: %s, %s", message, (char *)major_status_string.value, (char *)minor_status_string.value)); gss_release_buffer(&err_minor_status, &major_status_string); gss_release_buffer(&err_minor_status, &minor_status_string); } # endif /* DEBUG */ #endif /* HAVE_GSSAPI */ /* * 'cups_local_auth()' - Get the local authorization certificate if * available/applicable. */ static int /* O - 0 if available */ /* 1 if not available */ /* -1 error */ cups_local_auth(http_t *http) /* I - HTTP connection to server */ { #if defined(WIN32) || defined(__EMX__) /* * Currently WIN32 and OS-2 do not support the CUPS server... */ return (1); #else int pid; /* Current process ID */ FILE *fp; /* Certificate file */ char trc[16], /* Try Root Certificate parameter */ filename[1024]; /* Certificate filename */ _cups_globals_t *cg = _cupsGlobals(); /* Global data */ # if defined(HAVE_AUTHORIZATION_H) OSStatus status; /* Status */ AuthorizationItem auth_right; /* Authorization right */ AuthorizationRights auth_rights; /* Authorization rights */ AuthorizationFlags auth_flags; /* Authorization flags */ AuthorizationExternalForm auth_extrn; /* Authorization ref external */ char auth_key[1024]; /* Buffer */ char buffer[1024]; /* Buffer */ # endif /* HAVE_AUTHORIZATION_H */ DEBUG_printf(("7cups_local_auth(http=%p) hostaddr=%s, hostname=\"%s\"", (void *)http, httpAddrString(http->hostaddr, filename, sizeof(filename)), http->hostname)); /* * See if we are accessing localhost... */ if (!httpAddrLocalhost(http->hostaddr) && _cups_strcasecmp(http->hostname, "localhost") != 0) { DEBUG_puts("8cups_local_auth: Not a local connection!"); return (1); } # if defined(HAVE_AUTHORIZATION_H) /* * Delete any previous authorization reference... */ if (http->auth_ref) { AuthorizationFree(http->auth_ref, kAuthorizationFlagDefaults); http->auth_ref = NULL; } if (!getenv("GATEWAY_INTERFACE") && httpGetSubField2(http, HTTP_FIELD_WWW_AUTHENTICATE, "authkey", auth_key, sizeof(auth_key))) { status = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &http->auth_ref); if (status != errAuthorizationSuccess) { DEBUG_printf(("8cups_local_auth: AuthorizationCreate() returned %d (%s)", (int)status, cssmErrorString(status))); return (-1); } auth_right.name = auth_key; auth_right.valueLength = 0; auth_right.value = NULL; auth_right.flags = 0; auth_rights.count = 1; auth_rights.items = &auth_right; auth_flags = kAuthorizationFlagDefaults | kAuthorizationFlagPreAuthorize | kAuthorizationFlagInteractionAllowed | kAuthorizationFlagExtendRights; status = AuthorizationCopyRights(http->auth_ref, &auth_rights, kAuthorizationEmptyEnvironment, auth_flags, NULL); if (status == errAuthorizationSuccess) status = AuthorizationMakeExternalForm(http->auth_ref, &auth_extrn); if (status == errAuthorizationSuccess) { /* * Set the authorization string and return... */ httpEncode64_2(buffer, sizeof(buffer), (void *)&auth_extrn, sizeof(auth_extrn)); httpSetAuthString(http, "AuthRef", buffer); DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"", http->authstring)); return (0); } else if (status == errAuthorizationCanceled) return (-1); DEBUG_printf(("9cups_local_auth: AuthorizationCopyRights() returned %d (%s)", (int)status, cssmErrorString(status))); /* * Fall through to try certificates... */ } # endif /* HAVE_AUTHORIZATION_H */ # if defined(SO_PEERCRED) && defined(AF_LOCAL) /* * See if we can authenticate using the peer credentials provided over a * domain socket; if so, specify "PeerCred username" as the authentication * information... */ if ( # ifdef HAVE_GSSAPI _cups_strncasecmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Negotiate", 9) && # endif /* HAVE_GSSAPI */ # ifdef HAVE_AUTHORIZATION_H !httpGetSubField2(http, HTTP_FIELD_WWW_AUTHENTICATE, "authkey", auth_key, sizeof(auth_key)) && # endif /* HAVE_AUTHORIZATION_H */ http->hostaddr->addr.sa_family == AF_LOCAL && !getenv("GATEWAY_INTERFACE")) /* Not via CGI programs... */ { /* * Verify that the current cupsUser() matches the current UID... */ struct passwd *pwd; /* Password information */ const char *username; /* Current username */ username = cupsUser(); if ((pwd = getpwnam(username)) != NULL && pwd->pw_uid == getuid()) { httpSetAuthString(http, "PeerCred", username); DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"", http->authstring)); return (0); } } # endif /* SO_PEERCRED && AF_LOCAL */ /* * Try opening a certificate file for this PID. If that fails, * try the root certificate... */ pid = getpid(); snprintf(filename, sizeof(filename), "%s/certs/%d", cg->cups_statedir, pid); if ((fp = fopen(filename, "r")) == NULL && pid > 0) { /* * No certificate for this PID; see if we can get the root certificate... */ DEBUG_printf(("9cups_local_auth: Unable to open file %s: %s", filename, strerror(errno))); # ifdef HAVE_GSSAPI if (!_cups_strncasecmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Negotiate", 9)) { /* * Kerberos required, don't try the root certificate... */ return (1); } # endif /* HAVE_GSSAPI */ # ifdef HAVE_AUTHORIZATION_H if (httpGetSubField2(http, HTTP_FIELD_WWW_AUTHENTICATE, "authkey", auth_key, sizeof(auth_key))) { /* * Don't use the root certificate as a replacement for an authkey... */ return (1); } # endif /* HAVE_AUTHORIZATION_H */ if (!httpGetSubField2(http, HTTP_FIELD_WWW_AUTHENTICATE, "trc", trc, sizeof(trc))) { /* * Scheduler doesn't want us to use the root certificate... */ return (1); } snprintf(filename, sizeof(filename), "%s/certs/0", cg->cups_statedir); fp = fopen(filename, "r"); } if (fp) { /* * Read the certificate from the file... */ char certificate[33], /* Certificate string */ *certptr; /* Pointer to certificate string */ certptr = fgets(certificate, sizeof(certificate), fp); fclose(fp); if (certptr) { /* * Set the authorization string and return... */ httpSetAuthString(http, "Local", certificate); DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"", http->authstring)); return (0); } } return (1); #endif /* WIN32 || __EMX__ */ }