Commit baaa24fa authored by Lev Walkin's avatar Lev Walkin

added stack checking into ber_skip_length also

parent c500b3e1
......@@ -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) {
......
......@@ -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;
......
......@@ -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.
......
......@@ -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);
......
......@@ -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) {
......
......@@ -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) {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment