upstream: switch percent_expand() to use sshbuf instead of a limited

fixed buffer; ok markus@

OpenBSD-Commit-ID: 3f9ef20bca5ef5058b48c1cac67c53b9a1d15711

diff --git a/misc.c b/misc.c
index b90aac5c08d9c0a46922e2fa0c92172a3737c757..c94d2c2661e14ccb19fab5a6c95807d4d114ecd4 100644 (file)
--- a/misc.c
+++ b/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.139 2019/06/28 13:35:04 deraadt Exp $ */
+/* $OpenBSD: misc.c,v 1.140 2019/08/16 06:13:15 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -1049,13 +1049,18 @@ char *
 percent_expand(const char *string, ...)
 {
 #define EXPAND_MAX_KEYS        16
-       u_int num_keys, i, j;
+       u_int num_keys, i;
        struct {
                const char *key;
                const char *repl;
        } keys[EXPAND_MAX_KEYS];
-       char buf[4096];
+       struct sshbuf *buf;
        va_list ap;
+       int r;
+       char *ret;
+
+       if ((buf = sshbuf_new()) == NULL)
+               fatal("%s: sshbuf_new failed", __func__);
 
        /* Gather keys */
        va_start(ap, string);
@@ -1072,14 +1077,13 @@ percent_expand(const char *string, ...)
        va_end(ap);
 
        /* Expand string */
-       *buf = '\0';
        for (i = 0; *string != '\0'; string++) {
                if (*string != '%') {
  append:
-                       buf[i++] = *string;
-                       if (i >= sizeof(buf))
-                               fatal("%s: string too long", __func__);
-                       buf[i] = '\0';
+                       if ((r = sshbuf_put_u8(buf, *string)) != 0) {
+                               fatal("%s: sshbuf_put_u8: %s",
+                                   __func__, ssh_err(r));
+                       }
                        continue;
                }
                string++;
@@ -1088,18 +1092,23 @@ percent_expand(const char *string, ...)
                        goto append;
                if (*string == '\0')
                        fatal("%s: invalid format", __func__);
-               for (j = 0; j < num_keys; j++) {
-                       if (strchr(keys[j].key, *string) != NULL) {
-                               i = strlcat(buf, keys[j].repl, sizeof(buf));
-                               if (i >= sizeof(buf))
-                                       fatal("%s: string too long", __func__);
+               for (i = 0; i < num_keys; i++) {
+                       if (strchr(keys[i].key, *string) != NULL) {
+                               if ((r = sshbuf_put(buf, keys[i].repl,
+                                   strlen(keys[i].repl))) != 0) {
+                                       fatal("%s: sshbuf_put: %s",
+                                           __func__, ssh_err(r));
+                               }
                                break;
                        }
                }
-               if (j >= num_keys)
+               if (i >= num_keys)
                        fatal("%s: unknown key %%%c", __func__, *string);
        }
-       return (xstrdup(buf));
+       if ((ret = sshbuf_dup_string(buf)) == NULL)
+               fatal("%s: sshbuf_dup_string failed", __func__);
+       sshbuf_free(buf);
+       return ret;
 #undef EXPAND_MAX_KEYS
 }