+/* $OpenBSD: auth2.c,v 1.121 2009/06/22 05:39:28 dtucker Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
*/
#include "includes.h"
-RCSID("$OpenBSD: auth2.c,v 1.102 2003/08/26 09:58:43 markus Exp $");
-#include "ssh2.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+
+#include <fcntl.h>
+#include <pwd.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "atomicio.h"
#include "xmalloc.h"
+#include "ssh2.h"
#include "packet.h"
#include "log.h"
+#include "buffer.h"
#include "servconf.h"
#include "compat.h"
+#include "key.h"
+#include "hostfile.h"
#include "auth.h"
#include "dispatch.h"
#include "pathnames.h"
-#include "monitor_wrap.h"
+#include "buffer.h"
+#include "canohost.h"
#ifdef GSSAPI
#include "ssh-gss.h"
#endif
+#include "monitor_wrap.h"
/* import */
extern ServerOptions options;
extern u_char *session_id2;
extern u_int session_id2_len;
-
-Authctxt *x_authctxt = NULL;
+extern Buffer loginmsg;
/* methods */
extern Authmethod method_kbdint;
extern Authmethod method_hostbased;
#ifdef GSSAPI
+extern Authmethod method_external;
+extern Authmethod method_gsskeyex;
extern Authmethod method_gssapi;
+extern Authmethod method_gssapi_compat;
+#endif
+#ifdef JPAKE
+extern Authmethod method_jpake;
#endif
+static int log_flag = 0;
+
+
Authmethod *authmethods[] = {
&method_none,
&method_pubkey,
#ifdef GSSAPI
+ &method_gsskeyex,
+ &method_external,
&method_gssapi,
+ &method_gssapi_compat,
+#endif
+#ifdef JPAKE
+ &method_jpake,
#endif
&method_passwd,
&method_kbdint,
/* helper */
static Authmethod *authmethod_lookup(const char *);
static char *authmethods_get(void);
-int user_key_allowed(struct passwd *, Key *);
-int hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
-/*
- * loop until authctxt->success == TRUE
- */
+char *
+auth2_read_banner(void)
+{
+ struct stat st;
+ char *banner = NULL;
+ size_t len, n;
+ int fd;
+
+ if ((fd = open(options.banner, O_RDONLY)) == -1)
+ return (NULL);
+ if (fstat(fd, &st) == -1) {
+ close(fd);
+ return (NULL);
+ }
+ if (st.st_size > 1*1024*1024) {
+ close(fd);
+ return (NULL);
+ }
-Authctxt *
-do_authentication2(void)
+ len = (size_t)st.st_size; /* truncate */
+ banner = xmalloc(len + 1);
+ n = atomicio(read, fd, banner, len);
+ close(fd);
+
+ if (n != len) {
+ xfree(banner);
+ return (NULL);
+ }
+ banner[n] = '\0';
+
+ return (banner);
+}
+
+void
+userauth_send_banner(const char *msg)
+{
+ if (datafellows & SSH_BUG_BANNER)
+ return;
+
+ packet_start(SSH2_MSG_USERAUTH_BANNER);
+ packet_put_cstring(msg);
+ packet_put_cstring(""); /* language, unused */
+ packet_send();
+ debug("%s: sent", __func__);
+}
+
+static void
+userauth_banner(void)
{
- Authctxt *authctxt = authctxt_new();
+ char *banner = NULL;
- x_authctxt = authctxt; /*XXX*/
+ if (options.banner == NULL ||
+ strcasecmp(options.banner, "none") == 0 ||
+ (datafellows & SSH_BUG_BANNER) != 0)
+ return;
- /* challenge-response is implemented via keyboard interactive */
- if (options.challenge_response_authentication)
- options.kbd_interactive_authentication = 1;
+ if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
+ goto done;
+ userauth_send_banner(banner);
+done:
+ if (banner)
+ xfree(banner);
+}
+
+/*
+ * loop until authctxt->success == TRUE
+ */
+void
+do_authentication2(Authctxt *authctxt)
+{
dispatch_init(&dispatch_protocol_error);
dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
-
- return (authctxt);
}
+/*ARGSUSED*/
static void
input_service_request(int type, u_int32_t seq, void *ctxt)
{
xfree(service);
}
+/*ARGSUSED*/
static void
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
user = packet_get_string(NULL);
service = packet_get_string(NULL);
method = packet_get_string(NULL);
- debug("userauth-request for user %s service %s method %s", user, service, method);
+
+#ifdef GSSAPI
+ if (user[0] == '\0') {
+ debug("received empty username for %s", method);
+ if (strcmp(method, "external-keyx") == 0 ||
+ strcmp(method, "gssapi-keyex") == 0) {
+ char *lname = NULL;
+ PRIVSEP(ssh_gssapi_localname(&lname));
+ if (lname && lname[0] != '\0') {
+ xfree(user);
+ user = lname;
+ debug("set username to %s from gssapi context", user);
+ } else {
+ debug("failed to set username from gssapi context");
+ packet_send_debug("failed to set username from gssapi context");
+ }
+ }
+ }
+#endif
+
+ debug("userauth-request for user %s service %s method %s",
+ user[0] ? user : "<implicit>", service, method);
+ if (!log_flag) {
+ logit("SSH: Server;Ltype: Authname;Remote: %s-%d;Name: %s",
+ get_remote_ipaddr(), get_remote_port(),
+ user[0] ? user : "<implicit>");
+ log_flag = 1;
+ }
debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
if ((style = strchr(user, ':')) != NULL)
*style++ = 0;
- if (authctxt->attempt++ == 0) {
- /* setup auth context */
+ /* If first time or username changed or empty username,
+ setup/reset authentication context. */
+ if ((authctxt->attempt++ == 0) ||
+ (strcmp(user, authctxt->user) != 0) ||
+ (strcmp(user, "") == 0)) {
+ if (authctxt->user) {
+ xfree(authctxt->user);
+ authctxt->user = NULL;
+ }
+ authctxt->valid = 0;
+ authctxt->user = xstrdup(user);
+ if (strcmp(service, "ssh-connection") != 0) {
+ packet_disconnect("Unsupported service %s", service);
+ }
+#ifdef GSSAPI
+ /* If we're going to set the username based on the
+ GSSAPI context later, then wait until then to
+ verify it. Just put in placeholders for now. */
+ if ((strcmp(user, "") == 0) &&
+ ((strcmp(method, "gssapi") == 0) ||
+ (strcmp(method, "gssapi-with-mic") == 0))) {
+ authctxt->pw = fakepw();
+ } else {
+#endif
authctxt->pw = PRIVSEP(getpwnamallow(user));
- if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
+ if (authctxt->pw) {
authctxt->valid = 1;
debug2("input_userauth_request: setting up authctxt for %s", user);
-#ifdef USE_PAM
- if (options.use_pam)
- PRIVSEP(start_pam(authctxt->pw->pw_name));
-#endif
} else {
- logit("input_userauth_request: illegal user %s", user);
+ logit("input_userauth_request: invalid user %s", user);
authctxt->pw = fakepw();
-#ifdef USE_PAM
- if (options.use_pam)
- PRIVSEP(start_pam(user));
+#ifdef SSH_AUDIT_EVENTS
+ PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
}
- setproctitle("%s%s", authctxt->pw ? user : "unknown",
+#ifdef GSSAPI
+ } /* endif for setting username based on GSSAPI context */
+#endif
+#ifdef USE_PAM
+ if (options.use_pam)
+ PRIVSEP(start_pam(authctxt));
+#endif
+ setproctitle("%s%s", authctxt->valid ? user : "unknown",
use_privsep ? " [net]" : "");
- authctxt->user = xstrdup(user);
- authctxt->service = xstrdup(service);
- authctxt->style = style ? xstrdup(style) : NULL;
- if (use_privsep)
- mm_inform_authserv(service, style);
- } else if (strcmp(user, authctxt->user) != 0 ||
- strcmp(service, authctxt->service) != 0) {
- packet_disconnect("Change of username or service not allowed: "
+ if (authctxt->attempt == 1) {
+ authctxt->service = xstrdup(service);
+ authctxt->style = style ? xstrdup(style) : NULL;
+ if (use_privsep)
+ mm_inform_authserv(service, style);
+ userauth_banner();
+ }
+ }
+ if (strcmp(service, authctxt->service) != 0) {
+ packet_disconnect("Change of service not allowed: "
"(%s,%s) -> (%s,%s)",
authctxt->user, authctxt->service, user, service);
}
/* reset state */
auth2_challenge_stop(authctxt);
+#ifdef JPAKE
+ auth2_jpake_stop(authctxt);
+#endif
#ifdef GSSAPI
+ /* XXX move to auth2_gssapi_stop() */
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif
authctxt->postponed = 0;
+ authctxt->server_caused_failure = 0;
/* try to authenticate user */
m = authmethod_lookup(method);
- if (m != NULL) {
+ if (m != NULL && authctxt->failures < options.max_authtries) {
debug2("input_userauth_request: try method %s", method);
authenticated = m->userauth(authctxt);
}
/* Special handling for root */
if (authenticated && authctxt->pw->pw_uid == 0 &&
- !auth_root_allowed(method))
+ !auth_root_allowed(method)) {
authenticated = 0;
+#ifdef SSH_AUDIT_EVENTS
+ PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
+#endif
+ }
#ifdef USE_PAM
- if (options.use_pam && authenticated && !PRIVSEP(do_pam_account()))
- authenticated = 0;
+ if (options.use_pam && authenticated) {
+ if (!PRIVSEP(do_pam_account())) {
+ /* if PAM returned a message, send it to the user */
+ if (buffer_len(&loginmsg) > 0) {
+ buffer_append(&loginmsg, "\0", 1);
+ userauth_send_banner(buffer_ptr(&loginmsg));
+ packet_write_wait();
+ }
+ fatal("Access denied for user %s by PAM account "
+ "configuration", authctxt->user);
+ }
+ }
#endif
#ifdef _UNICOS
/* now we can break out */
authctxt->success = 1;
} else {
- if (authctxt->failures++ > AUTH_FAIL_MAX)
+ /* Dont count server configuration issues against the client */
+ /* Allow initial try of "none" auth without failure penalty */
+ if (!authctxt->server_caused_failure &&
+ (authctxt->attempt > 1 || strcmp(method, "none") != 0))
+ authctxt->failures++;
+ if (authctxt->failures >= options.max_authtries) {
+#ifdef SSH_AUDIT_EVENTS
+ PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES));
+#endif
packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
+ }
methods = authmethods_get();
packet_start(SSH2_MSG_USERAUTH_FAILURE);
packet_put_cstring(methods);
}
}
-/* get current user */
-
-struct passwd*
-auth_get_user(void)
-{
- return (x_authctxt != NULL && x_authctxt->valid) ? x_authctxt->pw : NULL;
-}
-
-#define DELIM ","
-
static char *
authmethods_get(void)
{
name ? name : "NULL");
return NULL;
}
+
andersk / gssapi-openssh.git / blobdiff