osmith/wireshark
1
0
Fork 0
forked from osmocom/wireshark
Code Pull requests Releases Wiki Activity

ssl-utils: add length validation to CertificateRequest

Browse source 
Add length validation to several fields in CertificateRequest. Clarify
specification, remove unnecessary length check and add TODO for TLS 1.3.

Change-Id: Ic3aca62d90e5fad6930beb371adf10d7b7b9fbe2
Reviewed-on: https://code.wireshark.org/review/20010
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
This commit is contained in:
Peter Wu 2017-02-08 00:38:52 +01:00
parent 0e08518915
commit 813625883c
1 changed files with 40 additions and 34 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

74
epan/dissectors/packet-ssl-utils.c
View file

@ -7162,7 +7162,7 @@ ssl_dissect_hnd_cert_req(ssl_common_dissect_t *hf, tvbuff_t *tvb, packet_info *p
proto_tree *tree, guint32 offset, guint32 offset_end,
const SslSession *session)
{
/*
/* From SSL 3.0 and up (note that since TLS 1.1 certificate_authorities can be empty):
* enum {
* rsa_sign(1), dss_sign(2), rsa_fixed_dh(3), dss_fixed_dh(4),
* (255)
@ -7204,8 +7204,7 @@ ssl_dissect_hnd_cert_req(ssl_common_dissect_t *hf, tvbuff_t *tvb, packet_info *p
*
* struct {
* ClientCertificateType certificate_types<1..2^8-1>;
* SignatureAndHashAlgorithm
* supported_signature_algorithms<2^16-1>;
* SignatureAndHashAlgorithm supported_signature_algorithms<2^16-1>;
* DistinguishedName certificate_authorities<0..2^16-1>;
* } CertificateRequest;
*
@ -7229,8 +7228,7 @@ ssl_dissect_hnd_cert_req(ssl_common_dissect_t *hf, tvbuff_t *tvb, packet_info *p
*/
proto_item *ti;
proto_tree *subtree;
guint8 cert_types_count;
gint dnames_length;
guint32 dnames_length = 0, next_offset;
asn1_ctx_t asn1_ctx;
if (!tree)
@ -7240,8 +7238,11 @@ ssl_dissect_hnd_cert_req(ssl_common_dissect_t *hf, tvbuff_t *tvb, packet_info *p
if (session->version == TLSV1DOT3_VERSION) {
guint32 context_length;
proto_tree_add_item_ret_uint(tree, hf->hf.hs_certificate_request_context_length,
tvb, offset, 1, ENC_NA, &context_length);
/* opaque certificate_request_context<0..2^8-1> */
if (!ssl_add_vector(hf, tvb, pinfo, tree, offset, offset_end, &context_length,
hf->hf.hs_certificate_request_context_length, 0, G_MAXUINT8)) {
return;
}
offset++;
if (context_length > 0) {
proto_tree_add_item(tree, hf->hf.hs_certificate_request_context,
@ -7249,26 +7250,26 @@ ssl_dissect_hnd_cert_req(ssl_common_dissect_t *hf, tvbuff_t *tvb, packet_info *p
offset += context_length;
}
} else {
cert_types_count = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(tree, hf->hf.hs_cert_types_count,
tvb, offset, 1, cert_types_count);
guint32 cert_types_count;
/* ClientCertificateType certificate_types<1..2^8-1> */
if (!ssl_add_vector(hf, tvb, pinfo, tree, offset, offset_end, &cert_types_count,
hf->hf.hs_cert_types_count, 1, G_MAXUINT8)) {
return;
}
offset++;
next_offset = offset + cert_types_count;
if (cert_types_count > 0) {
ti = proto_tree_add_none_format(tree,
hf->hf.hs_cert_types,
tvb, offset, cert_types_count,
"Certificate types (%u type%s)",
cert_types_count,
plurality(cert_types_count, "", "s"));
subtree = proto_item_add_subtree(ti, hf->ett.cert_types);
ti = proto_tree_add_none_format(tree,
hf->hf.hs_cert_types,
tvb, offset, cert_types_count,
"Certificate types (%u type%s)",
cert_types_count,
plurality(cert_types_count, "", "s"));
subtree = proto_item_add_subtree(ti, hf->ett.cert_types);
while (cert_types_count > 0) {
proto_tree_add_item(subtree, hf->hf.hs_cert_type,
tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
cert_types_count--;
}
while (offset < next_offset) {
proto_tree_add_item(subtree, hf->hf.hs_cert_type, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
}
}
@ -7283,10 +7284,13 @@ ssl_dissect_hnd_cert_req(ssl_common_dissect_t *hf, tvbuff_t *tvb, packet_info *p
break;
}
dnames_length = tvb_get_ntohs(tvb, offset);
proto_tree_add_uint(tree, hf->hf.hs_dnames_len,
tvb, offset, 2, dnames_length);
/* DistinguishedName certificate_authorities<0..2^16-1> */
if (!ssl_add_vector(hf, tvb, pinfo, tree, offset, offset_end, &dnames_length,
hf->hf.hs_dnames_len, 0, G_MAXUINT16)) {
return;
}
offset += 2;
next_offset = offset + dnames_length;
if (dnames_length > 0) {
ti = proto_tree_add_none_format(tree,
@ -7297,14 +7301,14 @@ ssl_dissect_hnd_cert_req(ssl_common_dissect_t *hf, tvbuff_t *tvb, packet_info *p
plurality(dnames_length, "", "s"));
subtree = proto_item_add_subtree(ti, hf->ett.dnames);
while (dnames_length > 0) {
while (offset < next_offset) {
/* get the length of the current certificate */
guint16 name_length;
name_length = tvb_get_ntohs(tvb, offset);
dnames_length -= 2 + name_length;
proto_tree_add_item(subtree, hf->hf.hs_dname_len,
tvb, offset, 2, ENC_BIG_ENDIAN);
guint32 name_length;
/* opaque DistinguishedName<1..2^16-1> */
if (!ssl_add_vector(hf, tvb, pinfo, subtree, offset, next_offset, &name_length,
hf->hf.hs_dname_len, 1, G_MAXUINT16)) {
return;
}
offset += 2;
dissect_x509if_DistinguishedName(FALSE, tvb, offset, &asn1_ctx,
@ -7312,6 +7316,8 @@ ssl_dissect_hnd_cert_req(ssl_common_dissect_t *hf, tvbuff_t *tvb, packet_info *p
offset += name_length;
}
}
/* TODO Extensions specific to certificates (TLS 1.3). */
}
/* Certificate and Certificate Request dissections. }}} */