1 files changed, 46 insertions, 1 deletions

diff --git a/misc.c b/misc.c
index 7adbcea1c..4bc07a42a 100644
--- a/misc.c
+++ b/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"
@@ -376,6 +376,51 @@ 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.
  */