ssl_cipher_process_rulestr: don't read outside rule_str buffer

If rule_str ended in a "-", "l" was incremented one byte past the
end of the buffer.  This resulted in an out-of-bounds read when "l"
is dereferenced at the end of the loop.  OK tb@

1 files changed, 3 insertions, 2 deletions

diff --git a/src/lib/libssl/ssl_ciph.c b/src/lib/libssl/ssl_ciph.c
index d304cfe6ec..106a9befdd 100644
--- a/src/lib/libssl/ssl_ciph.c
+++ b/src/lib/libssl/ssl_ciph.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_ciph.c,v 1.132 2022/09/04 07:55:32 tb Exp $ */
+/* $OpenBSD: ssl_ciph.c,v 1.133 2022/09/07 21:34:22 millert Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1011,7 +1011,8 @@ ssl_cipher_process_rulestr(const char *rule_str, CIPHER_ORDER **head_p,
                                  */
                                 SSLerrorx(SSL_R_INVALID_COMMAND);
                                 retval = found = 0;
-                                l++;
+                                if (ch != '\0')
+                                        l++;
                                 break;
                         }