From 2b93cbaa87a6a03a859b2d59d406ebfaba6a912a Mon Sep 17 00:00:00 2001
From: doug <doug@openbsd.org>
Date: Tue, 16 Jun 2015 06:11:39 +0000
Subject: [PATCH] Simplify cbs_get_any_asn1_element_internal based on comments
 from jsing@

---
 lib/libssl/bs_cbs.c             | 26 +++++++++++---------------
 lib/libssl/bytestring.h         |  4 ++--
 lib/libssl/src/ssl/bs_cbs.c     | 26 +++++++++++---------------
 lib/libssl/src/ssl/bytestring.h |  4 ++--
 4 files changed, 26 insertions(+), 34 deletions(-)

diff --git a/lib/libssl/bs_cbs.c b/lib/libssl/bs_cbs.c
index ba38303c18a..1b513c9a0e2 100644
--- a/lib/libssl/bs_cbs.c
+++ b/lib/libssl/bs_cbs.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bs_cbs.c,v 1.9 2015/06/15 07:35:49 doug Exp $	*/
+/*	$OpenBSD: bs_cbs.c,v 1.10 2015/06/16 06:11:39 doug Exp $	*/
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -262,21 +262,17 @@ cbs_get_any_asn1_element_internal(CBS *cbs, CBS *out, unsigned *out_tag,
 		/* Handle indefinite form length */
 		if (num_bytes == 0) {
 			/* DER encoding doesn't allow for indefinite form. */
-			if (strict) {
+			if (strict)
 				return 0;
 
-			} else {
-				if ((tag & CBS_ASN1_CONSTRUCTED) != 0 &&
-				    num_bytes == 0) {
-					/* indefinite length */
-					if (out_header_len != NULL)
-						*out_header_len = 2;
-					return CBS_get_bytes(cbs, out, 2);
-				} else {
-					/* Primitive cannot use indefinite. */
-					return 0;
-				}
-			}
+			/* Primitive cannot use indefinite in BER or DER. */
+			if ((tag & CBS_ASN1_CONSTRUCTED) == 0)
+				return 0;
+
+			/* Constructed, indefinite length allowed in BER. */
+			if (out_header_len != NULL)
+				*out_header_len = 2;
+			return CBS_get_bytes(cbs, out, 2);
 		}
 
 		/* CBS limitation. */
@@ -286,7 +282,7 @@ cbs_get_any_asn1_element_internal(CBS *cbs, CBS *out, unsigned *out_tag,
 		if (!cbs_get_u(&header, &len32, num_bytes))
 			return 0;
 
-		/* DER has a minimum length octet requirements. */
+		/* DER has a minimum length octet requirement. */
 		if (len32 < 128)
 			/* Should have used short form instead */
 			return 0;
diff --git a/lib/libssl/bytestring.h b/lib/libssl/bytestring.h
index d66ab65b919..ef824a0cead 100644
--- a/lib/libssl/bytestring.h
+++ b/lib/libssl/bytestring.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bytestring.h,v 1.7 2015/06/15 07:35:49 doug Exp $	*/
+/*	$OpenBSD: bytestring.h,v 1.8 2015/06/16 06:11:39 doug Exp $	*/
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -451,7 +451,7 @@ int CBB_add_asn1_uint64(CBB *cbb, uint64_t value);
 
 #ifdef LIBRESSL_INTERNAL
 /*
- * CBS_get_any_asn1_element sets |*out| to contain the next ASN.1 element from
+ * cbs_get_any_asn1_element sets |*out| to contain the next ASN.1 element from
  * |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to
  * the tag number and |*out_header_len| to the length of the ASN.1 header. If
  * strict mode is disabled and the element has indefinite length then |*out|
diff --git a/lib/libssl/src/ssl/bs_cbs.c b/lib/libssl/src/ssl/bs_cbs.c
index ba38303c18a..1b513c9a0e2 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 1.9 2015/06/15 07:35:49 doug Exp $	*/
+/*	$OpenBSD: bs_cbs.c,v 1.10 2015/06/16 06:11:39 doug Exp $	*/
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -262,21 +262,17 @@ cbs_get_any_asn1_element_internal(CBS *cbs, CBS *out, unsigned *out_tag,
 		/* Handle indefinite form length */
 		if (num_bytes == 0) {
 			/* DER encoding doesn't allow for indefinite form. */
-			if (strict) {
+			if (strict)
 				return 0;
 
-			} else {
-				if ((tag & CBS_ASN1_CONSTRUCTED) != 0 &&
-				    num_bytes == 0) {
-					/* indefinite length */
-					if (out_header_len != NULL)
-						*out_header_len = 2;
-					return CBS_get_bytes(cbs, out, 2);
-				} else {
-					/* Primitive cannot use indefinite. */
-					return 0;
-				}
-			}
+			/* Primitive cannot use indefinite in BER or DER. */
+			if ((tag & CBS_ASN1_CONSTRUCTED) == 0)
+				return 0;
+
+			/* Constructed, indefinite length allowed in BER. */
+			if (out_header_len != NULL)
+				*out_header_len = 2;
+			return CBS_get_bytes(cbs, out, 2);
 		}
 
 		/* CBS limitation. */
@@ -286,7 +282,7 @@ cbs_get_any_asn1_element_internal(CBS *cbs, CBS *out, unsigned *out_tag,
 		if (!cbs_get_u(&header, &len32, num_bytes))
 			return 0;
 
-		/* DER has a minimum length octet requirements. */
+		/* DER has a minimum length octet requirement. */
 		if (len32 < 128)
 			/* Should have used short form instead */
 			return 0;
diff --git a/lib/libssl/src/ssl/bytestring.h b/lib/libssl/src/ssl/bytestring.h
index d66ab65b919..ef824a0cead 100644
--- a/lib/libssl/src/ssl/bytestring.h
+++ b/lib/libssl/src/ssl/bytestring.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bytestring.h,v 1.7 2015/06/15 07:35:49 doug Exp $	*/
+/*	$OpenBSD: bytestring.h,v 1.8 2015/06/16 06:11:39 doug Exp $	*/
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -451,7 +451,7 @@ int CBB_add_asn1_uint64(CBB *cbb, uint64_t value);
 
 #ifdef LIBRESSL_INTERNAL
 /*
- * CBS_get_any_asn1_element sets |*out| to contain the next ASN.1 element from
+ * cbs_get_any_asn1_element sets |*out| to contain the next ASN.1 element from
  * |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to
  * the tag number and |*out_header_len| to the length of the ASN.1 header. If
  * strict mode is disabled and the element has indefinite length then |*out|
-- 
2.20.1