- dtucker@cvs.openbsd.org 2008/07/02 12:03:51

     [auth-rsa.c auth.c auth2-pubkey.c auth.h]
     Merge duplicate host key file checks, based in part on a patch from Rob
     Holland via bz #1348 .  Also checks for non-regular files during protocol
     1 RSA auth.  ok djm@

5 files changed, 58 insertions, 60 deletions

diff --git a/ChangeLog b/ChangeLog
index 9e7326d85..dc8048939 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -28,6 +28,11 @@
      [sshd_config sshd_config.5 sshd.8 servconf.c]
      increase default size of ssh protocol 1 ephemeral key from 768 to 1024
      bits; prodded by & ok dtucker@ ok deraadt@
+   - dtucker@cvs.openbsd.org 2008/07/02 12:03:51
+     [auth-rsa.c auth.c auth2-pubkey.c auth.h]
+     Merge duplicate host key file checks, based in part on a patch from Rob
+     Holland via bz #1348 .  Also checks for non-regular files during protocol
+     1 RSA auth.  ok djm@
 
 20080630
  - (djm) OpenBSD CVS Sync
@@ -4511,4 +4516,4 @@
    OpenServer 6 and add osr5bigcrypt support so when someone migrates
    passwords between UnixWare and OpenServer they will still work. OK dtucker@
 
-$Id: ChangeLog,v 1.5046 2008/07/02 12:35:43 dtucker Exp $
+$Id: ChangeLog,v 1.5047 2008/07/02 12:37:30 dtucker Exp $
diff --git a/auth-rsa.c b/auth-rsa.c
index 69f9a5896..bf5462076 100644
--- a/auth-rsa.c
+++ b/auth-rsa.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth-rsa.c,v 1.72 2006/11/06 21:25:27 markus Exp $ */
+/* $OpenBSD: auth-rsa.c,v 1.73 2008/07/02 12:03:51 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -173,7 +173,6 @@ auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
         u_int bits;
         FILE *f;
         u_long linenum = 0;
-        struct stat st;
         Key *key;
 
         /* Temporarily use the user's uid. */
@@ -182,27 +181,9 @@ auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
         /* The authorized keys. */
         file = authorized_keys_file(pw);
         debug("trying public RSA key file %s", file);
-
-        /* Fail quietly if file does not exist */
-        if (stat(file, &st) < 0) {
-                /* Restore the privileged uid. */
-                restore_uid();
-                xfree(file);
-                return (0);
-        }
-        /* Open the file containing the authorized keys. */
-        f = fopen(file, "r");
+        f = auth_openkeyfile(file, pw, options.strict_modes);
         if (!f) {
-                /* Restore the privileged uid. */
-                restore_uid();
-                xfree(file);
-                return (0);
-        }
-        if (options.strict_modes &&
-            secure_filename(f, file, pw, line, sizeof(line)) != 0) {
                 xfree(file);
-                fclose(f);
-                logit("Authentication refused: %s", line);
                 restore_uid();
                 return (0);
         }
diff --git a/auth.c b/auth.c
index f94c7d1d5..c2d298f1b 100644
--- a/auth.c
+++ b/auth.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth.c,v 1.78 2007/09/21 08:15:29 djm Exp $ */
+/* $OpenBSD: auth.c,v 1.79 2008/07/02 12:03:51 dtucker Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -32,6 +32,7 @@
 #include <netinet/in.h>
 
 #include <errno.h>
+#include <fcntl.h>
 #ifdef HAVE_PATHS_H
 # include <paths.h>
 #endif
@@ -410,7 +411,7 @@ check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host,
  *
  * Returns 0 on success and -1 on failure
  */
-int
+static int
 secure_filename(FILE *f, const char *file, struct passwd *pw,
     char *err, size_t errlen)
 {
@@ -470,6 +471,46 @@ secure_filename(FILE *f, const char *file, struct passwd *pw,
         return 0;
 }
 
+FILE *
+auth_openkeyfile(const char *file, struct passwd *pw, int strict_modes)
+{
+        char line[1024];
+        struct stat st;
+        int fd;
+        FILE *f;
+
+        /*
+         * Open the file containing the authorized keys
+         * Fail quietly if file does not exist
+         */
+        if ((fd = open(file, O_RDONLY|O_NONBLOCK)) == -1)
+                return NULL;
+
+        if (fstat(fd, &st) < 0) {
+                close(fd);
+                return NULL;
+        }
+        if (!S_ISREG(st.st_mode)) {
+                logit("User %s authorized keys %s is not a regular file",
+                    pw->pw_name, file);
+                close(fd);
+                return NULL;
+        }
+        unset_nonblock(fd);
+        if ((f = fdopen(fd, "r")) == NULL) {
+                close(fd);
+                return NULL;
+        }
+        if (options.strict_modes &&
+            secure_filename(f, file, pw, line, sizeof(line)) != 0) {
+                fclose(f);
+                logit("Authentication refused: %s", line);
+                return NULL;
+        }
+
+        return f;
+}
+
 struct passwd *
 getpwnamallow(const char *user)
 {
diff --git a/auth.h b/auth.h
index f752c1220..6a70f0eb6 100644
--- a/auth.h
+++ b/auth.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth.h,v 1.60 2007/09/21 08:15:29 djm Exp $ */
+/* $OpenBSD: auth.h,v 1.61 2008/07/02 12:03:51 dtucker Exp $ */
 
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
@@ -166,8 +166,7 @@ void	abandon_challenge_response(Authctxt *);
 char    *authorized_keys_file(struct passwd *);
 char    *authorized_keys_file2(struct passwd *);
 
-int
-secure_filename(FILE *, const char *, struct passwd *, char *, size_t);
+FILE    *auth_openkeyfile(const char *, struct passwd *, int);
 
 HostStatus
 check_key_in_hostfiles(struct passwd *, Key *, const char *,
diff --git a/auth2-pubkey.c b/auth2-pubkey.c
index 306515000..daa751ca0 100644
--- a/auth2-pubkey.c
+++ b/auth2-pubkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-pubkey.c,v 1.17 2008/06/13 14:18:51 dtucker Exp $ */
+/* $OpenBSD: auth2-pubkey.c,v 1.18 2008/07/02 12:03:51 dtucker Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -182,10 +182,9 @@ static int
 user_key_allowed2(struct passwd *pw, Key *key, char *file)
 {
         char line[SSH_MAX_PUBKEY_BYTES];
-        int found_key = 0, fd;
+        int found_key = 0;
         FILE *f;
         u_long linenum = 0;
-        struct stat st;
         Key *found;
         char *fp;
 
@@ -193,37 +192,10 @@ user_key_allowed2(struct passwd *pw, Key *key, char *file)
         temporarily_use_uid(pw);
 
         debug("trying public key file %s", file);
+        f = auth_openkeyfile(file, pw, options.strict_modes);
 
-        /*
-         * Open the file containing the authorized keys
-         * Fail quietly if file does not exist
-         */
-        if ((fd = open(file, O_RDONLY|O_NONBLOCK)) == -1) {
-                restore_uid();
-                return 0;
-        }
-        if (fstat(fd, &st) < 0) {
-                close(fd);
-                restore_uid();
-                return 0;
-        }
-        if (!S_ISREG(st.st_mode)) {
-                logit("User %s authorized keys %s is not a regular file",
-                    pw->pw_name, file);
-                close(fd);
-                restore_uid();
-                return 0;
-        }
-        unset_nonblock(fd);
-        if ((f = fdopen(fd, "r")) == NULL) {
-                close(fd);
-                restore_uid();
-                return 0;
-        }
-        if (options.strict_modes &&
-            secure_filename(f, file, pw, line, sizeof(line)) != 0) {
-                fclose(f);
-                logit("Authentication refused: %s", line);
+        if (!f) {
+                xfree(file);
                 restore_uid();
                 return 0;
         }