Import of OpenSSH 5.1p1

[gssapi-openssh.git] / openssh / auth2.c

diff --git a/openssh/auth2.c b/openssh/auth2.c
index 03d7f09dc680c8720803190479300a29aacf67d3..a835abfc6c3366241e9b94fa29ada5abd22e34b5 100644 (file)
--- a/openssh/auth2.c
+++ b/openssh/auth2.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2.c,v 1.116 2007/09/29 00:25:51 dtucker Exp $ */
+/* $OpenBSD: auth2.c,v 1.119 2008/07/04 23:30:16 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -26,12 +26,17 @@
 #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 "xmalloc.h"
+#include "atomicio.h"
 #include "ssh2.h"
 #include "packet.h"
 #include "log.h"
@@ -88,10 +93,74 @@ static void input_userauth_request(int, u_int32_t, void *);
 static Authmethod *authmethod_lookup(const char *);
 static char *authmethods_get(void);
 
+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)
 {
@@ -179,6 +248,7 @@ input_userauth_request(int type, u_int32_t seq, void *ctxt)
                authctxt->style = style ? xstrdup(style) : NULL;
                if (use_privsep)
                        mm_inform_authserv(service, style);
+               userauth_banner();
        } else if (strcmp(user, authctxt->user) != 0 ||
            strcmp(service, authctxt->service) != 0) {
                packet_disconnect("Change of username or service not allowed: "
@@ -197,7 +267,7 @@ input_userauth_request(int type, u_int32_t seq, void *ctxt)
 
        /* 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);
        }
@@ -264,7 +334,11 @@ userauth_finish(Authctxt *authctxt, int authenticated, char *method)
                /* now we can break out */
                authctxt->success = 1;
        } else {
-               if (authctxt->failures++ > options.max_authtries) {
+
+               /* Allow initial try of "none" auth without failure penalty */
+               if (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
@@ -320,3 +394,4 @@ authmethod_lookup(const char *name)
            name ? name : "NULL");
        return NULL;
 }
+