-/* $OpenBSD: auth2.c,v 1.115 2007/04/14 22:01:58 stevesk Exp $ */
+/* $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"
#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 "dispatch.h"
#include "pathnames.h"
#include "buffer.h"
+#include "canohost.h"
#ifdef GSSAPI
#include "ssh-gss.h"
extern Authmethod method_kbdint;
extern Authmethod method_hostbased;
#ifdef GSSAPI
+extern Authmethod method_gsskeyex;
extern Authmethod method_gssapi;
#endif
+#ifdef JPAKE
+extern Authmethod method_jpake;
+#endif
+
+static int log_flag = 0;
+
Authmethod *authmethods[] = {
&method_none,
&method_pubkey,
#ifdef GSSAPI
+ &method_gsskeyex,
&method_gssapi,
+#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 *);
+
+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);
+ }
+
+ 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)
+{
+ char *banner = NULL;
+
+ if (options.banner == NULL ||
+ strcasecmp(options.banner, "none") == 0 ||
+ (datafellows & SSH_BUG_BANNER) != 0)
+ return;
+
+ 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)
{
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, "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));
- authctxt->user = xstrdup(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);
} else {
PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
}
+#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->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);
}
/* now we can break out */
authctxt->success = 1;
} else {
- if (authctxt->failures++ > options.max_authtries) {
+ /* 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
name ? name : "NULL");
return NULL;
}
+
andersk / gssapi-openssh.git / blobdiff