From baaa24fa5ceafe7a36e429ee9bfd6eb2e7131bf5 Mon Sep 17 00:00:00 2001
From: Lev Walkin <vlm@lionet.info>
Date: Wed, 29 Sep 2004 14:19:14 +0000
Subject: [PATCH] added stack checking into ber_skip_length also
---
skeletons/ber_decoder.c | 6 ++++--
skeletons/ber_tlv_length.c | 21 +++++++++++++++++++--
skeletons/ber_tlv_length.h | 5 ++++-
skeletons/constr_CHOICE.c | 2 +-
skeletons/constr_SEQUENCE.c | 4 ++--
skeletons/constr_SET.c | 4 ++--
6 files changed, 32 insertions(+), 10 deletions(-)
diff --git a/skeletons/ber_decoder.c b/skeletons/ber_decoder.c
index 95d71017..f932b3b2 100644
--- a/skeletons/ber_decoder.c
+++ b/skeletons/ber_decoder.c
@@ -71,10 +71,12 @@ ber_check_tags(asn_codec_ctx_t *opt_codec_ctx,
int step = opt_ctx ? opt_ctx->step : 0; /* Where we left previously */
int tagno;
+ /*
+ * Make sure we didn't exceed the maximum stack size.
+ */
if(opt_codec_ctx && opt_codec_ctx->max_stack_size) {
ptrdiff_t usedstack = ((char *)opt_codec_ctx - (char *)&size);
- /* do not change the semantics:
- * double negative is required to avoid int wrap-around */
+ /* double negative is required to avoid int wrap-around */
if(usedstack > 0) usedstack = -usedstack;
ASN_DEBUG("Current stack size %ld", -(long)usedstack);
if(usedstack < -(ptrdiff_t)opt_codec_ctx->max_stack_size) {
diff --git a/skeletons/ber_tlv_length.c b/skeletons/ber_tlv_length.c
index a0ec1e5d..10a9e1c3 100644
--- a/skeletons/ber_tlv_length.c
+++ b/skeletons/ber_tlv_length.c
@@ -74,12 +74,28 @@ ber_fetch_length(int _is_constructed, void *bufptr, size_t size,
}
ssize_t
-ber_skip_length(int _is_constructed, void *ptr, size_t size) {
+ber_skip_length(asn_codec_ctx_t *opt_codec_ctx,
+ int _is_constructed, void *ptr, size_t size) {
ber_tlv_len_t vlen; /* Length of V in TLV */
ssize_t tl; /* Length of L in TLV */
ssize_t ll; /* Length of L in TLV */
size_t skip;
+ /*
+ * Make sure we didn't exceed the maximum stack size.
+ */
+ if(opt_codec_ctx && opt_codec_ctx->max_stack_size) {
+ ptrdiff_t usedstack = ((char *)opt_codec_ctx - (char *)&size);
+ /* double negative is required to avoid int wrap-around */
+ if(usedstack > 0) usedstack = -usedstack;
+ ASN_DEBUG("Current stack size %ld", -(long)usedstack);
+ if(usedstack < -(ptrdiff_t)opt_codec_ctx->max_stack_size) {
+ ASN_DEBUG("Stack limit %ld reached",
+ (long)opt_codec_ctx->max_stack_size);
+ return -1;
+ }
+ }
+
/*
* Determine the size of L in TLV.
*/
@@ -107,7 +123,8 @@ ber_skip_length(int _is_constructed, void *ptr, size_t size) {
tl = ber_fetch_tag(ptr, size, &tag);
if(tl <= 0) return tl;
- ll = ber_skip_length(BER_TLV_CONSTRUCTED(ptr),
+ ll = ber_skip_length(opt_codec_ctx,
+ BER_TLV_CONSTRUCTED(ptr),
((char *)ptr) + tl, size - tl);
if(ll <= 0) return ll;
diff --git a/skeletons/ber_tlv_length.h b/skeletons/ber_tlv_length.h
index 5222bbf4..9d99e663 100644
--- a/skeletons/ber_tlv_length.h
+++ b/skeletons/ber_tlv_length.h
@@ -27,7 +27,10 @@ ssize_t ber_fetch_length(int _is_constructed, void *bufptr, size_t size,
* RETURN VALUES:
* Standard {-1,0,>0} convention.
*/
-ssize_t ber_skip_length(int _is_constructed, void *bufptr, size_t size);
+struct asn_codec_ctx_s; /* Forward declaration */
+ssize_t ber_skip_length(
+ struct asn_codec_ctx_s *opt_codec_ctx, /* optional context */
+ int _is_constructed, void *bufptr, size_t size);
/*
* This function serializes the length (L from TLV) in DER format.
diff --git a/skeletons/constr_CHOICE.c b/skeletons/constr_CHOICE.c
index ab158462..4db6d7b1 100644
--- a/skeletons/constr_CHOICE.c
+++ b/skeletons/constr_CHOICE.c
@@ -209,7 +209,7 @@ CHOICE_decode_ber(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
ASN_DEBUG("Skipping unknown tag %s",
ber_tlv_tag_string(tlv_tag));
- skip = ber_skip_length(
+ skip = ber_skip_length(opt_codec_ctx,
BER_TLV_CONSTRUCTED(ptr),
(char *)ptr + tag_len, LEFT - tag_len);
diff --git a/skeletons/constr_SEQUENCE.c b/skeletons/constr_SEQUENCE.c
index 740ce570..07c77728 100644
--- a/skeletons/constr_SEQUENCE.c
+++ b/skeletons/constr_SEQUENCE.c
@@ -352,7 +352,7 @@ SEQUENCE_decode_ber(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
/* Skip this tag */
ssize_t skip;
- skip = ber_skip_length(
+ skip = ber_skip_length(opt_codec_ctx,
BER_TLV_CONSTRUCTED(ptr),
(char *)ptr + tag_len, LEFT - tag_len);
ASN_DEBUG("Skip length %d in %s",
@@ -474,7 +474,7 @@ SEQUENCE_decode_ber(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
RETURN(RC_FAIL);
}
- ll = ber_skip_length(
+ ll = ber_skip_length(opt_codec_ctx,
BER_TLV_CONSTRUCTED(ptr),
(char *)ptr + tl, LEFT - tl);
switch(ll) {
diff --git a/skeletons/constr_SET.c b/skeletons/constr_SET.c
index 647bb83a..d9f93c3b 100644
--- a/skeletons/constr_SET.c
+++ b/skeletons/constr_SET.c
@@ -259,7 +259,7 @@ SET_decode_ber(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
ASN_DEBUG("Skipping unknown tag %s",
ber_tlv_tag_string(tlv_tag));
- skip = ber_skip_length(
+ skip = ber_skip_length(opt_codec_ctx,
BER_TLV_CONSTRUCTED(ptr),
(char *)ptr + tag_len, LEFT - tag_len);
@@ -381,7 +381,7 @@ SET_decode_ber(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
RETURN(RC_FAIL);
}
- ll = ber_skip_length(
+ ll = ber_skip_length(opt_codec_ctx,
BER_TLV_CONSTRUCTED(ptr),
(char *)ptr + tl, LEFT - tl);
switch(ll) {
--
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