- 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@

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 $

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);
 	}

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)
 {

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 *,

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;
 	}