one small tweak to avoid ever going off the end of a string.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/lib/libc/crypt/bcrypt.c b/src/lib/libc/crypt/bcrypt.c
index a077c99de5..7fcb2a5187 100644
--- a/src/lib/libc/crypt/bcrypt.c
+++ b/src/lib/libc/crypt/bcrypt.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: bcrypt.c,v 1.38 2014/04/19 15:17:59 tedu Exp $        */
+/*      $OpenBSD: bcrypt.c,v 1.39 2014/04/19 15:19:20 tedu Exp $        */
 
 /*
  * Copyright (c) 2014 Ted Unangst <tedu@openbsd.org>
@@ -276,10 +276,12 @@ decode_base64(u_int8_t *buffer, size_t len, const char *b64data)
 
         while (bp < buffer + len) {
                 c1 = CHAR64(*p);
-                c2 = CHAR64(*(p + 1));
-
                 /* Invalid data */
-                if (c1 == 255 || c2 == 255)
+                if (c1 == 255)
+                        return -1;
+
+                c2 = CHAR64(*(p + 1));
+                if (c2 == 255)
                         return -1;
 
                 *bp++ = (c1 << 2) | ((c2 & 0x30) >> 4);