From: jsing <jsing@openbsd.org>
Date: Thu, 5 May 2022 19:18:56 +0000 (+0000)
Subject: Use size_t for ASN.1 lengths.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=47fd635d385b82d6f17831526807d8b9a7f3b7f6;p=openbsd

Use size_t for ASN.1 lengths.

Change asn1_get_length_cbs() and asn1_get_object_cbs() to handle and return
a length as a size_t rather than a uint32_t. This makes it simpler and less
error prone in the callers.

Suggested by and ok tb@
---

diff --git a/lib/libcrypto/asn1/asn1_lib.c b/lib/libcrypto/asn1/asn1_lib.c
index 97ce6caeefe..ac8da0e61d4 100644
--- a/lib/libcrypto/asn1/asn1_lib.c
+++ b/lib/libcrypto/asn1/asn1_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: asn1_lib.c,v 1.53 2022/04/28 18:30:57 jsing Exp $ */
+/* $OpenBSD: asn1_lib.c,v 1.54 2022/05/05 19:18:56 jsing Exp $ */
 /*
  * Copyright (c) 2021 Joel Sing <jsing@openbsd.org>
  *
@@ -78,10 +78,10 @@ asn1_get_identifier_cbs(CBS *cbs, int der_mode, uint8_t *out_class,
 
 int
 asn1_get_length_cbs(CBS *cbs, int der_mode, int *out_indefinite,
-    uint32_t *out_length)
+    size_t *out_length)
 {
 	uint8_t len_bytes;
-	uint32_t length;
+	size_t length;
 	uint8_t val;
 
 	/*
@@ -127,7 +127,7 @@ asn1_get_length_cbs(CBS *cbs, int der_mode, int *out_indefinite,
 			return 0;
 		if (der_mode && length == 0 && val == 0)
 			return 0;
-		if (length > (UINT32_MAX >> 8))
+		if (length > (SIZE_MAX >> 8))
 			return 0;
 		length = (length << 8) | val;
 	}
@@ -140,11 +140,12 @@ asn1_get_length_cbs(CBS *cbs, int der_mode, int *out_indefinite,
 int
 asn1_get_object_cbs(CBS *cbs, int der_mode, uint8_t *out_tag_class,
     int *out_constructed, uint32_t *out_tag_number, int *out_indefinite,
-    uint32_t *out_length)
+    size_t *out_length)
 {
 	int constructed, indefinite;
-	uint32_t tag_number, length;
+	uint32_t tag_number;
 	uint8_t tag_class;
+	size_t length;
 
 	*out_tag_class = 0;
 	*out_constructed = 0;
@@ -176,8 +177,9 @@ asn1_get_primitive(CBS *cbs, int der_mode, uint32_t *out_tag_number,
     CBS *out_content)
 {
 	int constructed, indefinite;
-	uint32_t tag_number, length;
+	uint32_t tag_number;
 	uint8_t tag_class;
+	size_t length;
 
 	*out_tag_number = 0;
 
diff --git a/lib/libcrypto/asn1/asn1_locl.h b/lib/libcrypto/asn1/asn1_locl.h
index 86907aa8f07..79239faea17 100644
--- a/lib/libcrypto/asn1/asn1_locl.h
+++ b/lib/libcrypto/asn1/asn1_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: asn1_locl.h,v 1.28 2022/04/28 18:30:57 jsing Exp $ */
+/* $OpenBSD: asn1_locl.h,v 1.29 2022/05/05 19:18:56 jsing Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2006.
  */
@@ -196,10 +196,10 @@ int asn1_d2i_read_bio(BIO *in, BUF_MEM **pb);
 int asn1_get_identifier_cbs(CBS *cbs, int der_mode, uint8_t *out_class,
     int *out_constructed, uint32_t *out_tag_number);
 int asn1_get_length_cbs(CBS *cbs, int der_mode, int *out_indefinite,
-    uint32_t *out_length);
+    size_t *out_length);
 int asn1_get_object_cbs(CBS *cbs, int der_mode, uint8_t *out_class,
     int *out_constructed, uint32_t *out_tag_number, int *out_indefinite,
-    uint32_t *out_length);
+    size_t *out_length);
 int asn1_get_primitive(CBS *cbs, int der_mode, uint32_t *out_tag_number,
     CBS *out_content);
 
diff --git a/lib/libcrypto/asn1/asn1_old_lib.c b/lib/libcrypto/asn1/asn1_old_lib.c
index e41a5ea2575..a4d3cc71b41 100644
--- a/lib/libcrypto/asn1/asn1_old_lib.c
+++ b/lib/libcrypto/asn1/asn1_old_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: asn1_old_lib.c,v 1.3 2022/01/14 07:57:17 tb Exp $ */
+/* $OpenBSD: asn1_old_lib.c,v 1.4 2022/05/05 19:18:56 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -72,8 +72,9 @@ ASN1_get_object(const unsigned char **pp, long *plength, int *ptag,
     int *pclass, long omax)
 {
 	int constructed, indefinite;
-	uint32_t tag_number, length;
+	uint32_t tag_number;
 	uint8_t tag_class;
+	size_t length;
 	CBS cbs;
 	int ret = 0;
 
@@ -99,7 +100,7 @@ ASN1_get_object(const unsigned char **pp, long *plength, int *ptag,
 	 * signal an error by setting the 8th bit in the return value... but we
 	 * still provide all of the decoded data.
 	 */
-	if (length > CBS_len(&cbs)) {
+	if (length > CBS_len(&cbs) || length > LONG_MAX) {
 		ASN1error(ASN1_R_TOO_LONG);
 		ret = 0x80;
 	}
diff --git a/lib/libcrypto/asn1/tasn_dec.c b/lib/libcrypto/asn1/tasn_dec.c
index 0131e3c27c2..103774fc195 100644
--- a/lib/libcrypto/asn1/tasn_dec.c
+++ b/lib/libcrypto/asn1/tasn_dec.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tasn_dec.c,v 1.57 2022/05/04 10:57:48 jsing Exp $ */
+/* $OpenBSD: tasn_dec.c,v 1.58 2022/05/05 19:18:56 jsing Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2000.
  */
@@ -1049,9 +1049,10 @@ asn1_check_tag_cbs(CBS *cbs, size_t *out_len, int *out_tag, uint8_t *out_class,
     char *out_indefinite, char *out_constructed, int expected_tag,
     int expected_class, char optional)
 {
-	uint32_t tag_number, length;
 	int constructed, indefinite;
+	uint32_t tag_number;
 	uint8_t tag_class;
+	size_t length;
 
 	if (out_len != NULL)
 		*out_len = 0;
@@ -1096,7 +1097,7 @@ asn1_check_tag_cbs(CBS *cbs, size_t *out_len, int *out_tag, uint8_t *out_class,
 		return 0;
 	}
 
-	if (tag_number > INT_MAX || CBS_len(cbs) > INT_MAX) {
+	if (tag_number > INT_MAX) {
 		ASN1error(ASN1_R_TOO_LONG);
 		return 0;
 	}