replace tilde_expand_filename with a simpler implementation, ahead of more

whacking; ok deraadt@

4 files changed, 50 insertions, 81 deletions

diff --git a/usr.bin/ssh/lib/Makefile b/usr.bin/ssh/lib/Makefile
index 7b4eace82be..78cbb0495dd 100644
--- a/usr.bin/ssh/lib/Makefile
+++ b/usr.bin/ssh/lib/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.50 2004/12/22 02:13:19 djm Exp $
+#	$OpenBSD: Makefile,v 1.51 2005/04/09 04:32:54 djm Exp $
 
 .PATH:		${.CURDIR}/..
 
@@ -7,7 +7,7 @@ SRCS=	authfd.c authfile.c bufaux.c buffer.c canohost.c channels.c \
 	cipher.c cipher-3des1.c cipher-bf1.c cipher-ctr.c \
 	cleanup.c compat.c compress.c crc32.c deattack.c fatal.c \
 	hostfile.c log.c match.c nchan.c packet.c readpass.c \
-	rsa.c tildexpand.c ttymodes.c xmalloc.c atomicio.c \
+	rsa.c ttymodes.c xmalloc.c atomicio.c \
 	key.c dispatch.c kex.c mac.c uidswap.c uuencode.c misc.c \
 	ssh-dss.c ssh-rsa.c dh.c kexdh.c kexgex.c \
 	kexdhc.c kexgexc.c scard.c msg.c progressmeter.c dns.c \
diff --git a/usr.bin/ssh/misc.c b/usr.bin/ssh/misc.c
index 3d3af188288..7372ee13bd9 100644
--- a/usr.bin/ssh/misc.c
+++ b/usr.bin/ssh/misc.c
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: misc.c,v 1.29 2005/03/10 22:01:05 deraadt Exp $");
+RCSID("$OpenBSD: misc.c,v 1.30 2005/04/09 04:32:54 djm Exp $");
 
 #include "misc.h"
 #include "log.h"
@@ -370,6 +370,51 @@ addargs(arglist *args, char *fmt, ...)
 }
 
 /*
+ * Expands tildes in the file name.  Returns data allocated by xmalloc.
+ * Warning: this calls getpw*.
+ */
+char *
+tilde_expand_filename(const char *filename, uid_t uid)
+{
+	const char *path;
+	char user[128], ret[MAXPATHLEN];
+	struct passwd *pw;
+	int len;
+
+	if (*filename != '~')
+		return (xstrdup(filename));
+	filename++;
+
+	path = strchr(filename, '/');
+	if (path != NULL && path > filename) {		/* ~user/path */
+		if (path - filename > sizeof(user) - 1)
+			fatal("tilde_expand_filename: ~username too long");
+		memcpy(user, filename, path - filename);
+		user[path - filename] = '\0';
+		if ((pw = getpwnam(user)) == NULL)
+			fatal("tilde_expand_filename: No such user %s", user);
+	} else if ((pw = getpwuid(uid)) == NULL)	/* ~/path */
+		fatal("tilde_expand_filename: No such uid %d", uid);
+
+	if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
+		fatal("tilde_expand_filename: Path too long");
+
+	/* Make sure directory has a trailing '/' */
+	len = strlen(pw->pw_dir);
+	if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
+	    strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
+		fatal("tilde_expand_filename: Path too long");
+
+	/* Skip leading '/' from specified path */
+	if (path != NULL)
+		filename = path + 1;
+	if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
+		fatal("tilde_expand_filename: Path too long");
+
+	return (xstrdup(ret));
+}
+
+/*
  * Read an entire line from a public key file into a static buffer, discarding
  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
  */
diff --git a/usr.bin/ssh/misc.h b/usr.bin/ssh/misc.h
index 8bbc87f0dbd..798d80fbf3f 100644
--- a/usr.bin/ssh/misc.h
+++ b/usr.bin/ssh/misc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: misc.h,v 1.21 2005/03/01 10:09:52 djm Exp $	*/
+/*	$OpenBSD: misc.h,v 1.22 2005/04/09 04:32:54 djm Exp $	*/
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -24,6 +24,7 @@ char	*hpdelim(char **);
 char	*cleanhostname(char *);
 char	*colon(char *);
 long	 convtime(const char *);
+char	*tilde_expand_filename(const char *, uid_t);
 
 struct passwd *pwcopy(struct passwd *);
 
@@ -35,10 +36,6 @@ struct arglist {
 };
 void	 addargs(arglist *, char *, ...) __attribute__((format(printf, 2, 3)));
 
-/* tildexpand.c */
-
-char	*tilde_expand_filename(const char *, uid_t);
-
 /* readpass.c */
 
 #define RP_ECHO			0x0001
diff --git a/usr.bin/ssh/tildexpand.c b/usr.bin/ssh/tildexpand.c
deleted file mode 100644
index cedb653b244..00000000000
--- a/usr.bin/ssh/tildexpand.c
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * Author: Tatu Ylonen <ylo@cs.hut.fi>
- * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
- *                    All rights reserved
- *
- * As far as I am concerned, the code I have written for this software
- * can be used freely for any purpose.  Any derived versions of this
- * software must be clearly marked as such, and if the derived work is
- * incompatible with the protocol description in the RFC file, it must be
- * called by a name other than "ssh" or "Secure Shell".
- */
-
-#include "includes.h"
-RCSID("$OpenBSD: tildexpand.c,v 1.15 2004/05/21 08:43:03 markus Exp $");
-
-#include "xmalloc.h"
-#include "log.h"
-#include "misc.h"
-
-/*
- * Expands tildes in the file name.  Returns data allocated by xmalloc.
- * Warning: this calls getpw*.
- */
-char *
-tilde_expand_filename(const char *filename, uid_t my_uid)
-{
-	const char *cp;
-	u_int userlen;
-	char *expanded;
-	struct passwd *pw;
-	char user[100];
-	int len;
-
-	/* Return immediately if no tilde. */
-	if (filename[0] != '~')
-		return xstrdup(filename);
-
-	/* Skip the tilde. */
-	filename++;
-
-	/* Find where the username ends. */
-	cp = strchr(filename, '/');
-	if (cp)
-		userlen = cp - filename;	/* Something after username. */
-	else
-		userlen = strlen(filename);	/* Nothing after username. */
-	if (userlen == 0)
-		pw = getpwuid(my_uid);		/* Own home directory. */
-	else {
-		/* Tilde refers to someone elses home directory. */
-		if (userlen > sizeof(user) - 1)
-			fatal("User name after tilde too long.");
-		memcpy(user, filename, userlen);
-		user[userlen] = 0;
-		pw = getpwnam(user);
-	}
-	if (!pw)
-		fatal("Unknown user %100s.", user);
-
-	/* If referring to someones home directory, return it now. */
-	if (!cp) {
-		/* Only home directory specified */
-		return xstrdup(pw->pw_dir);
-	}
-	/* Build a path combining the specified directory and path. */
-	len = strlen(pw->pw_dir) + strlen(cp + 1) + 2;
-	if (len > MAXPATHLEN)
-		fatal("Home directory too long (%d > %d", len-1, MAXPATHLEN-1);
-	expanded = xmalloc(len);
-	snprintf(expanded, len, "%s%s%s", pw->pw_dir,
-	    strcmp(pw->pw_dir, "/") ? "/" : "", cp + 1);
-	return expanded;
-}