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- Fix validation failure in case upstream forwarder (ISC BIND) does

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not have the same trust anchors and decides to insert unsigned NS
  record in authority section.


git-svn-id: file:///svn/unbound/trunk@3329 be551aaa-1e26-0410-a405-d3ace91eadb9
This commit is contained in:
Wouter Wijngaards 2015-02-09 11:44:46 +00:00
parent 3ef33154e5
commit e08aa7c5e1
5 changed files with 232 additions and 0 deletions
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5
doc/Changelog
View file

@ -1,3 +1,8 @@
9 February 2015: Wouter
- Fix validation failure in case upstream forwarder (ISC BIND) does
not have the same trust anchors and decides to insert unsigned NS
record in authority section.
2 February 2015: Wouter
- infra-cache-min-rtt patch from Florian Riehm, for expected long
uplink roundtrip times.

151
testdata/val_spurious_ns.rpl vendored Normal file
View file

@ -0,0 +1,151 @@
; config options
; The island of trust is at example.com
server:
trust-anchor: "example.com. 3600 IN DS 2854 3 1 46e4ffc6e9a4793b488954bd3f0cc6af0dfb201b"
val-override-date: "20070916134226"
target-fetch-policy: "0 0 0 0 0"
stub-zone:
name: "."
stub-addr: 193.0.14.129 # K.ROOT-SERVERS.NET.
CONFIG_END
SCENARIO_BEGIN Test validator with spurious unsigned NS in auth section
; K.ROOT-SERVERS.NET.
RANGE_BEGIN 0 100
ADDRESS 193.0.14.129
ENTRY_BEGIN
MATCH opcode qtype qname
ADJUST copy_id
REPLY QR NOERROR
SECTION QUESTION
. IN NS
SECTION ANSWER
. IN NS K.ROOT-SERVERS.NET.
SECTION ADDITIONAL
K.ROOT-SERVERS.NET. IN A 193.0.14.129
ENTRY_END
ENTRY_BEGIN
MATCH opcode qtype qname
ADJUST copy_id
REPLY QR NOERROR
SECTION QUESTION
www.example.com. IN A
SECTION AUTHORITY
com. IN NS a.gtld-servers.net.
SECTION ADDITIONAL
a.gtld-servers.net. IN A 192.5.6.30
ENTRY_END
RANGE_END
; a.gtld-servers.net.
RANGE_BEGIN 0 100
ADDRESS 192.5.6.30
ENTRY_BEGIN
MATCH opcode qtype qname
ADJUST copy_id
REPLY QR NOERROR
SECTION QUESTION
com. IN NS
SECTION ANSWER
com. IN NS a.gtld-servers.net.
SECTION ADDITIONAL
a.gtld-servers.net. IN A 192.5.6.30
ENTRY_END
ENTRY_BEGIN
MATCH opcode qtype qname
ADJUST copy_id
REPLY QR NOERROR
SECTION QUESTION
www.example.com. IN A
SECTION AUTHORITY
example.com. IN NS ns.example.com.
SECTION ADDITIONAL
ns.example.com. IN A 1.2.3.4
ENTRY_END
RANGE_END
; ns.example.com.
RANGE_BEGIN 0 100
ADDRESS 1.2.3.4
ENTRY_BEGIN
MATCH opcode qtype qname
ADJUST copy_id
REPLY QR NOERROR
SECTION QUESTION
example.com. IN NS
SECTION ANSWER
example.com. IN NS ns.example.com.
example.com. 3600 IN RRSIG NS 3 2 3600 20070926134150 20070829134150 2854 example.com. MC0CFQCN+qHdJxoI/2tNKwsb08pra/G7aAIUAWA5sDdJTbrXA1/3OaesGBAO3sI= ;{id = 2854}
SECTION ADDITIONAL
ns.example.com. IN A 1.2.3.4
ns.example.com. 3600 IN RRSIG A 3 3 3600 20070926135752 20070829135752 2854 example.com. MC0CFQCMSWxVehgOQLoYclB9PIAbNP229AIUeH0vNNGJhjnZiqgIOKvs1EhzqAo= ;{id = 2854}
ENTRY_END
; response to DNSKEY priming query
ENTRY_BEGIN
MATCH opcode qtype qname
ADJUST copy_id
REPLY QR NOERROR
SECTION QUESTION
example.com. IN DNSKEY
SECTION ANSWER
example.com. 3600 IN DNSKEY 256 3 3 ALXLUsWqUrY3JYER3T4TBJII s70j+sDS/UT2QRp61SE7S3E EXopNXoFE73JLRmvpi/UrOO/Vz4Se 6wXv/CYCKjGw06U4WRgR YXcpEhJROyNapmdIKSx hOzfLVE1gqA0PweZR8d tY3aNQSRn3sPpwJr6Mi /PqQKAMMrZ9ckJpf1+b QMOOvxgzz2U1GS18b3y ZKcgTMEaJzd/GZYzi/B N2DzQ0MsrSwYXfsNLFO Bbs8PJMW4LYIxeeOe6rUgkWOF 7CC9Dh/dduQ1QrsJhmZAEFfd6ByYV+ ;{id = 2854 (zsk), size = 1688b}
example.com. 3600 IN RRSIG DNSKEY 3 2 3600 20070926134802 20070829134802 2854 example.com. MCwCFG1yhRNtTEa3Eno2zhVVuy2EJX3wAhQeLyUp6+UXcpC5qGNu9tkrTEgPUg== ;{id = 2854}
SECTION AUTHORITY
example.com. IN NS ns.example.com.
example.com. 3600 IN RRSIG NS 3 2 3600 20070926134150 20070829134150 2854 example.com. MC0CFQCN+qHdJxoI/2tNKwsb08pra/G7aAIUAWA5sDdJTbrXA1/3OaesGBAO3sI= ;{id = 2854}
SECTION ADDITIONAL
ns.example.com. IN A 1.2.3.4
ns.example.com. 3600 IN RRSIG A 3 3 3600 20070926135752 20070829135752 2854 example.com. MC0CFQCMSWxVehgOQLoYclB9PIAbNP229AIUeH0vNNGJhjnZiqgIOKvs1EhzqAo= ;{id = 2854}
ENTRY_END
; response to query of interest
ENTRY_BEGIN
MATCH opcode qtype qname
ADJUST copy_id
REPLY QR NOERROR
SECTION QUESTION
www.example.com. IN A
SECTION ANSWER
www.example.com. IN A 10.20.30.40
ns.example.com. 3600 IN RRSIG A 3 3 3600 20070926134150 20070829134150 2854 example.com. MC0CFQCQMyTjn7WWwpwAR1LlVeLpRgZGuQIUCcJDEkwAuzytTDRlYK7nIMwH1CM= ;{id = 2854}
SECTION AUTHORITY
example.com. IN NS ns.example.com.
;example.com. 3600 IN RRSIG NS 3 2 3600 20070926134150 20070829134150 2854 example.com. MC0CFQCN+qHdJxoI/2tNKwsb08pra/G7aAIUAWA5sDdJTbrXA1/3OaesGBAO3sI= ;{id = 2854}
SECTION ADDITIONAL
ns.example.com. IN A 1.2.3.4
www.example.com. 3600 IN RRSIG A 3 3 3600 20070926134150 20070829134150 2854 example.com. MC0CFC99iE9K5y2WNgI0gFvBWaTi9wm6AhUAoUqOpDtG5Zct+Qr9F3mSdnbc6V4= ;{id = 2854}
ENTRY_END
RANGE_END
STEP 1 QUERY
ENTRY_BEGIN
REPLY RD DO
SECTION QUESTION
www.example.com. IN A
ENTRY_END
; recursion happens here.
STEP 10 CHECK_ANSWER
ENTRY_BEGIN
MATCH all
REPLY QR RD RA AD DO NOERROR
SECTION QUESTION
www.example.com. IN A
SECTION ANSWER
www.example.com. IN A 10.20.30.40
www.example.com. 3600 IN RRSIG A 3 3 3600 20070926134150 20070829134150 2854 example.com. MC0CFC99iE9K5y2WNgI0gFvBWaTi9wm6AhUAoUqOpDtG5Zct+Qr9F3mSdnbc6V4= ;{id = 2854}
SECTION AUTHORITY
; removed by spurious NS record removal code
;;example.com. IN NS ns.example.com.
;;example.com. 3600 IN RRSIG NS 3 2 3600 20070926134150 20070829134150 2854 example.com. MC0CFQCN+qHdJxoI/2tNKwsb08pra/G7aAIUAWA5sDdJTbrXA1/3OaesGBAO3sI= ;{id = 2854}
SECTION ADDITIONAL
ns.example.com. IN A 1.2.3.4
ns.example.com. 3600 IN RRSIG A 3 3 3600 20070926134150 20070829134150 2854 example.com. MC0CFQCQMyTjn7WWwpwAR1LlVeLpRgZGuQIUCcJDEkwAuzytTDRlYK7nIMwH1CM= ;{id = 2854}
ENTRY_END
SCENARIO_END

12
validator/val_utils.c
View file

@ -846,6 +846,18 @@ val_fill_reply(struct reply_info* chase, struct reply_info* orig,
chase->ar_numrrsets;
}
void val_reply_remove_auth(struct reply_info* rep, size_t index)
{
log_assert(index < rep->rrset_count);
log_assert(index >= rep->an_numrrsets);
log_assert(index < rep->an_numrrsets+rep->ns_numrrsets);
memmove(rep->rrsets+index, rep->rrsets+index+1,
sizeof(struct ub_packed_rrset_key*)*
(rep->rrset_count - index - 1));
rep->ns_numrrsets--;
rep->rrset_count--;
}
void
val_check_nonsecure(struct val_env* ve, struct reply_info* rep)
{

7
validator/val_utils.h
View file

@ -294,6 +294,13 @@ int val_chase_cname(struct query_info* qchase, struct reply_info* rep,
void val_fill_reply(struct reply_info* chase, struct reply_info* orig,
size_t cname_skip, uint8_t* name, size_t len, uint8_t* signer);
/**
* Remove rrset with index from reply, from the authority section.
* @param rep: reply to remove it from.
* @param index: rrset to remove, must be in the authority section.
*/
void val_reply_remove_auth(struct reply_info* rep, size_t index);
/**
* Remove all unsigned or non-secure status rrsets from NS and AR sections.
* So that unsigned data does not get let through to clients, when we have

57
validator/validator.c
View file

@ -574,6 +574,61 @@ detect_wrongly_truncated(struct reply_info* rep)
return 1;
}
/**
* For messages that are not referrals, if the chase reply contains an
* unsigned NS record in the authority section it could have been
* inserted by a (BIND) forwarder that thinks the zone is insecure, and
* that has an NS record without signatures in cache. Remove the NS
* record since the reply does not hinge on that record (in the authority
* section), but do not remove it if it removes the last record from the
* answer+authority sections.
* @param chase_reply: the chased reply, we have a key for this contents,
* so we should have signatures for these rrsets and not having
* signatures means it will be bogus.
* @param orig_reply: original reply, remove NS from there as well because
* we cannot mark the NS record as DNSSEC valid because it is not
* validated by signatures.
*/
static void
remove_spurious_authority(struct reply_info* chase_reply,
struct reply_info* orig_reply)
{
size_t i, found = 0;
int remove = 0;
/* if no answer and only 1 auth RRset, do not remove that one */
if(chase_reply->an_numrrsets == 0 && chase_reply->ns_numrrsets == 1)
return;
/* search authority section for unsigned NS records */
for(i = chase_reply->an_numrrsets;
i < chase_reply->an_numrrsets+chase_reply->ns_numrrsets; i++) {
struct packed_rrset_data* d = (struct packed_rrset_data*)
chase_reply->rrsets[i]->entry.data;
if(ntohs(chase_reply->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS
&& d->rrsig_count == 0) {
found = i;
remove = 1;
break;
}
}
/* see if we found the entry */
if(!remove) return;
log_rrset_key(VERB_ALGO, "Removing spurious unsigned NS record "
"(likely inserted by forwarder)", chase_reply->rrsets[found]);
/* find rrset in orig_reply */
for(i = orig_reply->an_numrrsets;
i < orig_reply->an_numrrsets+orig_reply->ns_numrrsets; i++) {
if(ntohs(orig_reply->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS
&& query_dname_compare(orig_reply->rrsets[i]->rk.dname,
chase_reply->rrsets[found]->rk.dname) == 0) {
/* remove from orig_msg */
val_reply_remove_auth(orig_reply, i);
break;
}
}
/* remove rrset from chase_reply */
val_reply_remove_auth(chase_reply, found);
}
/**
* Given a "positive" response -- a response that contains an answer to the
@ -1642,6 +1697,8 @@ processValidate(struct module_qstate* qstate, struct val_qstate* vq,
}
subtype = val_classify_response(qstate->query_flags, &qstate->qinfo,
&vq->qchase, vq->orig_msg->rep, vq->rrset_skip);
if(subtype != VAL_CLASS_REFERRAL)
remove_spurious_authority(vq->chase_reply, vq->orig_msg->rep);
/* check signatures in the message;
* answer and authority must be valid, additional is only checked. */