Add a new function CBS_offset() to report the current offset in the data.

"why not" miod@, sure jsing@

2 files changed, 15 insertions, 2 deletions

diff --git a/lib/libssl/src/ssl/bs_cbs.c b/lib/libssl/src/ssl/bs_cbs.c
index 1b513c9a0e2..1368fe0fd7f 100644
--- a/lib/libssl/src/ssl/bs_cbs.c
+++ b/lib/libssl/src/ssl/bs_cbs.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bs_cbs.c,v 1.10 2015/06/16 06:11:39 doug Exp $	*/
+/*	$OpenBSD: bs_cbs.c,v 1.11 2015/06/17 07:00:22 doug Exp $	*/
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -28,6 +28,7 @@ void
 CBS_init(CBS *cbs, const uint8_t *data, size_t len)
 {
 	cbs->data = data;
+	cbs->initial_len = len;
 	cbs->len = len;
 }
 
@@ -43,6 +44,12 @@ cbs_get(CBS *cbs, const uint8_t **p, size_t n)
 	return 1;
 }
 
+size_t
+CBS_offset(const CBS *cbs)
+{
+	return cbs->initial_len - cbs->len;
+}
+
 int
 CBS_skip(CBS *cbs, size_t len)
 {
diff --git a/lib/libssl/src/ssl/bytestring.h b/lib/libssl/src/ssl/bytestring.h
index 07be6ddd50e..80ca00d77a4 100644
--- a/lib/libssl/src/ssl/bytestring.h
+++ b/lib/libssl/src/ssl/bytestring.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bytestring.h,v 1.9 2015/06/16 06:37:58 doug Exp $	*/
+/*	$OpenBSD: bytestring.h,v 1.10 2015/06/17 07:00:22 doug Exp $	*/
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -40,6 +40,7 @@ extern "C" {
 /* CRYPTO ByteString */
 typedef struct cbs_st {
 	const uint8_t *data;
+	size_t initial_len;
 	size_t len;
 } CBS;
 
@@ -66,6 +67,11 @@ const uint8_t *CBS_data(const CBS *cbs);
 size_t CBS_len(const CBS *cbs);
 
 /*
+ * CBS_offset returns the current offset into the original data of |cbs|.
+ */
+size_t CBS_offset(const CBS *cbs);
+
+/*
  * CBS_stow copies the current contents of |cbs| into |*out_ptr| and
  * |*out_len|. If |*out_ptr| is not NULL, the contents are freed with
  * free. It returns one on success and zero on allocation failure. On