From: Guus Sliepen <guus@tinc-vpn.org>
Date: Fri, 8 Aug 2003 22:11:54 +0000 (+0000)
Subject: Simpler checking of permissions on private RSA key and other fixes.
X-Git-Tag: import-tinc-1.1~785^2~84
X-Git-Url: https://git.meshlink.io/?a=commitdiff_plain;h=9bde92ce97d5503ff2d31dcc6f0648902580ec14;p=meshlink

Simpler checking of permissions on private RSA key and other fixes.
---

diff --git a/src/conf.c b/src/conf.c
index e927abdb..3feb1503 100644
--- a/src/conf.c
+++ b/src/conf.c
@@ -19,7 +19,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: conf.c,v 1.9.4.74 2003/08/08 14:59:27 guus Exp $
+    $Id: conf.c,v 1.9.4.75 2003/08/08 22:11:54 guus Exp $
 */
 
 #include "system.h"
@@ -424,97 +424,7 @@ bool read_server_config()
 	return x == 0;
 }
 
-bool is_safe_path(const char *file)
-{
-#if !(defined(HAVE_CYGWIN) || defined(HAVE_MINGW))
-	char *p;
-	const char *f;
-	char x;
-	struct stat s;
-	char l[MAXBUFSIZE];
-
-	if(*file != '/') {
-		logger(LOG_ERR, _("`%s' is not an absolute path"), file);
-		return false;
-	}
-
-	p = strrchr(file, '/');
-
-	if(p == file)				/* It's in the root */
-		p++;
-
-	x = *p;
-	*p = '\0';
-
-	f = file;
-
-check1:
-	if(lstat(f, &s) < 0) {
-		logger(LOG_ERR, _("Couldn't stat `%s': %s"), f, strerror(errno));
-		return false;
-	}
-
-	if(s.st_uid != geteuid()) {
-		logger(LOG_ERR, _("`%s' is owned by UID %d instead of %d"),
-			   f, s.st_uid, geteuid());
-		return false;
-	}
-
-	if(S_ISLNK(s.st_mode)) {
-		logger(LOG_WARNING, _("Warning: `%s' is a symlink"), f);
-
-		if(readlink(f, l, MAXBUFSIZE) < 0) {
-			logger(LOG_ERR, _("Unable to read symbolic link `%s': %s"), f,
-				   strerror(errno));
-			return false;
-		}
-
-		f = l;
-		goto check1;
-	}
-
-	*p = x;
-	f = file;
-
-check2:
-	if(lstat(f, &s) < 0 && errno != ENOENT) {
-		logger(LOG_ERR, _("Couldn't stat `%s': %s"), f, strerror(errno));
-		return false;
-	}
-
-	if(errno == ENOENT)
-		return true;
-
-	if(s.st_uid != geteuid()) {
-		logger(LOG_ERR, _("`%s' is owned by UID %d instead of %d"),
-			   f, s.st_uid, geteuid());
-		return false;
-	}
-
-	if(S_ISLNK(s.st_mode)) {
-		logger(LOG_WARNING, _("Warning: `%s' is a symlink"), f);
-
-		if(readlink(f, l, MAXBUFSIZE) < 0) {
-			logger(LOG_ERR, _("Unable to read symbolic link `%s': %s"), f,
-				   strerror(errno));
-			return false;
-		}
-
-		f = l;
-		goto check2;
-	}
-
-	if(s.st_mode & 0007) {
-		/* Accessible by others */
-		logger(LOG_ERR, _("`%s' has unsecure permissions"), f);
-		return false;
-	}
-#endif
-
-	return true;
-}
-
-FILE *ask_and_safe_open(const char *filename, const char *what, bool safe, const char *mode)
+FILE *ask_and_open(const char *filename, const char *what, const char *mode)
 {
 	FILE *r;
 	char *directory;
@@ -573,17 +483,6 @@ FILE *ask_and_safe_open(const char *filename, const char *what, bool safe, const
 		return NULL;
 	}
 
-	/* Then check the file for nasty attacks */
-	if(safe) {
-		if(!is_safe_path(fn)) {		/* Do not permit any directories that are readable or writeable by other users. */
-			fprintf(stderr, _("The file `%s' (or any of the leading directories) has unsafe permissions.\n"
-					 "I will not create or overwrite this file.\n"), fn);
-			fclose(r);
-			free(fn);
-			return NULL;
-		}
-	}
-
 	free(fn);
 
 	return r;
diff --git a/src/conf.h b/src/conf.h
index 8960f087..ba235c3d 100644
--- a/src/conf.h
+++ b/src/conf.h
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: conf.h,v 1.6.4.42 2003/07/30 21:52:41 guus Exp $
+    $Id: conf.h,v 1.6.4.43 2003/08/08 22:11:54 guus Exp $
 */
 
 #ifndef __TINC_CONF_H__
@@ -57,7 +57,7 @@ extern bool get_config_subnet(const config_t *, struct subnet_t **);
 
 extern int read_config_file(avl_tree_t *, const char *);
 extern bool read_server_config(void);
-extern FILE *ask_and_safe_open(const char *, const char *, bool, const char *);
+extern FILE *ask_and_open(const char *, const char *, const char *);
 extern bool is_safe_path(const char *);
 
 #endif							/* __TINC_CONF_H__ */
diff --git a/src/meta.c b/src/meta.c
index 18315ad1..c2fbd7ed 100644
--- a/src/meta.c
+++ b/src/meta.c
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: meta.c,v 1.1.2.39 2003/08/08 14:24:09 guus Exp $
+    $Id: meta.c,v 1.1.2.40 2003/08/08 22:11:54 guus Exp $
 */
 
 #include "system.h"
@@ -54,10 +54,10 @@ bool send_meta(connection_t *c, char *buffer, int length)
 	while(length) {
 		result = send(c->socket, bufp, length, 0);
 		if(result <= 0) {
-			if(!errno || errno == EPIPE)
+			if(!errno || errno == EPIPE) {
 				ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection closed by %s (%s)"),
 						   c->name, c->hostname);
-			else if(errno == EINTR)
+			} else if(errno == EINTR)
 				continue;
 			else
 				logger(LOG_ERR, _("Sending meta data to %s (%s) failed: %s"), c->name,
@@ -121,10 +121,10 @@ bool receive_meta(connection_t *c)
 	lenin = recv(c->socket, c->buffer + c->buflen, MAXBUFSIZE - c->buflen, 0);
 
 	if(lenin <= 0) {
-		if(!lenin || !errno)
+		if(!lenin || !errno) {
 			ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection closed by %s (%s)"),
 					   c->name, c->hostname);
-		else if(errno == EINTR)
+		} else if(errno == EINTR)
 			return true;
 		else
 			logger(LOG_ERR, _("Metadata socket read error for %s (%s): %s"),
diff --git a/src/net_setup.c b/src/net_setup.c
index 5bbaa799..c7c12505 100644
--- a/src/net_setup.c
+++ b/src/net_setup.c
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: net_setup.c,v 1.1.2.41 2003/07/30 11:50:45 guus Exp $
+    $Id: net_setup.c,v 1.1.2.42 2003/08/08 22:11:54 guus Exp $
 */
 
 #include "system.h"
@@ -149,6 +149,7 @@ bool read_rsa_private_key(void)
 {
 	FILE *fp;
 	char *fname, *key;
+	struct stat s;
 
 	cp();
 
@@ -164,32 +165,39 @@ bool read_rsa_private_key(void)
 	if(!get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
 		asprintf(&fname, "%s/rsa_key.priv", confbase);
 
-	if(is_safe_path(fname)) {
-		fp = fopen(fname, "r");
+	fp = fopen(fname, "r");
 
-		if(!fp) {
-			logger(LOG_ERR, _("Error reading RSA private key file `%s': %s"),
-				   fname, strerror(errno));
-			free(fname);
-			return false;
-		}
+	if(!fp) {
+		logger(LOG_ERR, _("Error reading RSA private key file `%s': %s"),
+			   fname, strerror(errno));
+		free(fname);
+		return false;
+	}
 
+#if !defined(HAVE_MINGW) && !defined(HAVE_CYGWIN)
+	if(fstat(fileno(fp), &s)) {
+		logger(LOG_ERR, _("Could not stat RSA private key file `%s': %s'"),
+				fname, strerror(errno));
 		free(fname);
-		myself->connection->rsa_key =
-			PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
-		fclose(fp);
+		return false;
+	}
 
-		if(!myself->connection->rsa_key) {
-			logger(LOG_ERR, _("Reading RSA private key file `%s' failed: %s"),
-				   fname, strerror(errno));
-			return false;
-		}
+	if(s.st_mode & ~0700)
+		logger(LOG_WARNING, _("Warning: insecure file permissions for RSA private key file `%s'!"), fname);
+#endif
 
-		return true;
+	myself->connection->rsa_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
+	fclose(fp);
+
+	if(!myself->connection->rsa_key) {
+		logger(LOG_ERR, _("Reading RSA private key file `%s' failed: %s"),
+			   fname, strerror(errno));
+		free(fname);
+		return false;
 	}
 
 	free(fname);
-	return false;
+	return true;
 }
 
 /*
diff --git a/src/process.c b/src/process.c
index d81fdd69..0ec98802 100644
--- a/src/process.c
+++ b/src/process.c
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: process.c,v 1.1.2.68 2003/08/08 19:56:11 guus Exp $
+    $Id: process.c,v 1.1.2.69 2003/08/08 22:11:54 guus Exp $
 */
 
 #include "system.h"
@@ -359,7 +359,6 @@ bool detach(void)
 bool execute_script(const char *name, char **envp)
 {
 #ifdef HAVE_SYSTEM
-	pid_t pid;
 	int status;
 	struct stat s;
 	char *scriptname;
@@ -394,22 +393,20 @@ bool execute_script(const char *name, char **envp)
 	if(status != -1) {
 		if(WIFEXITED(status)) {	/* Child exited by itself */
 			if(WEXITSTATUS(status)) {
-				logger(LOG_ERR, _("Process %d (%s) exited with non-zero status %d"),
-					   pid, name, WEXITSTATUS(status));
+				logger(LOG_ERR, _("Script %s exited with non-zero status %d"),
+					   name, WEXITSTATUS(status));
 				return false;
 			}
 		} else if(WIFSIGNALED(status)) {	/* Child was killed by a signal */
-			logger(LOG_ERR, _("Process %d (%s) was killed by signal %d (%s)"), pid,
+			logger(LOG_ERR, _("Script %s was killed by signal %d (%s)"),
 				   name, WTERMSIG(status), strsignal(WTERMSIG(status)));
 			return false;
 		} else {			/* Something strange happened */
-			logger(LOG_ERR, _("Process %d (%s) terminated abnormally"), pid,
-				   name);
+			logger(LOG_ERR, _("Script %s terminated abnormally"), name);
 			return false;
 		}
 	} else {
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "system",
-			   strerror(errno));
+		logger(LOG_ERR, _("System call `%s' failed: %s"), "system", strerror(errno));
 		return false;
 	}
 #endif
diff --git a/src/tincd.c b/src/tincd.c
index a37a6125..cec0ee5e 100644
--- a/src/tincd.c
+++ b/src/tincd.c
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: tincd.c,v 1.10.4.84 2003/08/08 19:45:21 guus Exp $
+    $Id: tincd.c,v 1.10.4.85 2003/08/08 22:11:54 guus Exp $
 */
 
 #include "system.h"
@@ -300,11 +300,16 @@ static bool keygen(int bits)
 		fprintf(stderr, _("Done.\n"));
 
 	asprintf(&filename, "%s/rsa_key.priv", confbase);
-	f = ask_and_safe_open(filename, _("private RSA key"), true, "a");
+	f = ask_and_open(filename, _("private RSA key"), "a");
 
 	if(!f)
 		return false;
-
+  
+#ifdef HAVE_FCHMOD
+	/* Make it unreadable for others. */
+	fchmod(fileno(f), 0600);
+#endif
+		
 	if(ftell(f))
 		fprintf(stderr, _("Appending key to existing contents.\nMake sure only one key is stored in the file.\n"));
 
@@ -319,7 +324,7 @@ static bool keygen(int bits)
 	else
 		asprintf(&filename, "%s/rsa_key.pub", confbase);
 
-	f = ask_and_safe_open(filename, _("public RSA key"), false, "a");
+	f = ask_and_open(filename, _("public RSA key"), "a");
 
 	if(!f)
 		return false;