/* -*- Mode: C; tab-width: 4 -*-
*
* Copyright (c) 2011-2013 Apple Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __DNSSEC_H
#define __DNSSEC_H
#include "CryptoAlg.h"
#include "mDNSDebug.h"
typedef enum
{
RRVS_rr, RRVS_rrsig, RRVS_key, RRVS_rrsig_key, RRVS_ds, RRVS_done,
} RRVerifierSet;
typedef struct RRVerifier_struct RRVerifier;
typedef struct DNSSECVerifier_struct DNSSECVerifier;
typedef struct AuthChain_struct AuthChain;
typedef struct InsecureContext_struct InsecureContext;
struct RRVerifier_struct
{
RRVerifier *next;
mDNSu16 rrtype;
mDNSu16 rrclass;
mDNSu32 rroriginalttl;
mDNSu16 rdlength;
mDNSu16 found;
mDNSu32 namehash;
mDNSu32 rdatahash;
domainname name;
mDNSu8 *rdata;
};
// Each AuthChain element has one rrset (with multiple resource records of same type), rrsig and key
// that validates the rrset.
struct AuthChain_struct
{
AuthChain *next; // Next element in the chain
RRVerifier *rrset; // RRSET that is authenticated
RRVerifier *rrsig; // Signature for that RRSET
RRVerifier *key; // Public key for that RRSET
};
#define ResetAuthChain(dv) { \
(dv)->ac = mDNSNULL; \
(dv)->actail = &((dv)->ac); \
}
typedef void DNSSECVerifierCallback (mDNS *const m, DNSSECVerifier *dv, DNSSECStatus status);
//
// When we do a validation for a question, there might be additional validations that needs to be done e.g.,
// wildcard expanded answer. It is also possible that in the case of nsec we need to prove both that a wildcard
// does not apply and the closest encloser proves that name does not exist. We identify these with the following
// flags.
//
// Note: In the following, by "marking the validation", we mean that as part of validation we need to prove
// the ones that are marked with.
//
// A wildcard may be used to answer a question. In that case, we need to verify that the right wildcard was
// used in answering the question. This is done by marking the validation with WILDCARD_PROVES_ANSWER_EXPANDED.
//
// Sometimes we get a NXDOMAIN response. In this case, we may have a wildcard where we need to prove
// that the wildcard proves that the name does not exist. This is done by marking the validation with
// WILDCARD_PROVES_NONAME_EXISTS.
//
// In the case of NODATA error, sometimes the name may exist but the query type does not exist. This is done by
// marking the validation with NSEC_PROVES_NOTYPE_EXISTS.
//
// In both NXDOMAIN and NODATA proofs, we may have to prove that the NAME does not exist. This is done by marking
// the validation with NSEC_PROVES_NONAME_EXISTS.
//
#define WILDCARD_PROVES_ANSWER_EXPANDED 0x00000001
#define WILDCARD_PROVES_NONAME_EXISTS 0x00000002
#define NSEC_PROVES_NOTYPE_EXISTS 0x00000004
#define NSEC_PROVES_NONAME_EXISTS 0x00000008
#define NSEC3_OPT_OUT 0x00000010 // OptOut was set in NSEC3
struct DNSSECVerifier_struct
{
domainname origName; // Original question name that needs verification
mDNSu16 origType; // Original question type corresponding to origName
mDNSu16 currQtype; // Current question type that is being verified
mDNSInterfaceID InterfaceID; // InterfaceID of the question
DNSQuestion q;
mDNSu8 recursed; // Number of times recursed during validation
mDNSu8 ValidationRequired; // Copy of the question's ValidationRequired status
mDNSu8 InsecureProofDone;
mDNSu8 NumPackets; // Number of packets that we send on the wire for DNSSEC verification.
mDNSs32 StartTime; // Time the DNSSEC verification starts
mDNSu32 flags;
RRVerifierSet next;
domainname *wildcardName; // set if the answer is wildcard expanded
RRVerifier *pendingNSEC;
DNSSECVerifierCallback *DVCallback;
DNSSECVerifier *parent;
RRVerifier *rrset; // rrset for which we have to verify
RRVerifier *rrsig; // RRSIG for rrset
RRVerifier *key; // DNSKEY for rrset
RRVerifier *rrsigKey; // RRSIG for DNSKEY
RRVerifier *ds; // DS for DNSKEY set in parent zone
AuthChain *saveac;
AuthChain *ac;
AuthChain **actail;
AlgContext *ctx;
};
struct InsecureContext_struct
{
DNSSECVerifier *dv; // dv for which we are doing the insecure proof
mDNSu8 skip; // labels to skip for forming the name from origName
DNSSECStatus status; // status to deliver when done
mDNSu8 triggerLabelCount; // Label count of the name that triggered the insecure proof
DNSQuestion q;
};
#define LogDNSSEC LogOperation
#define DNS_SERIAL_GT(a, b) ((int)((a) - (b)) > 0)
#define DNS_SERIAL_LT(a, b) ((int)((a) - (b)) < 0)
extern void StartDNSSECVerification(mDNS *const m, void *context);
extern RRVerifier* AllocateRRVerifier(const ResourceRecord *const rr, mStatus *status);
extern mStatus AddRRSetToVerifier(DNSSECVerifier *dv, const ResourceRecord *const rr, RRVerifier *rv, RRVerifierSet set);
extern void VerifySignature(mDNS *const m, DNSSECVerifier *dv, DNSQuestion *q);
extern void FreeDNSSECVerifier(mDNS *const m, DNSSECVerifier *dv);
extern DNSSECVerifier *AllocateDNSSECVerifier(mDNS *const m, const domainname *name, mDNSu16 rrtype, mDNSInterfaceID InterfaceID,
mDNSu8 ValidationRequired, DNSSECVerifierCallback dvcallback, mDNSQuestionCallback qcallback);
extern void InitializeQuestion(mDNS *const m, DNSQuestion *question, mDNSInterfaceID InterfaceID, const domainname *qname,
mDNSu16 qtype, mDNSQuestionCallback *callback, void *context);
extern void ValidateRRSIG(DNSSECVerifier *dv, RRVerifierSet type, const ResourceRecord *const rr);
extern void AuthChainLink(DNSSECVerifier *dv, AuthChain *ae);
extern mStatus DNSNameToLowerCase(domainname *d, domainname *result);
extern int DNSMemCmp(const mDNSu8 *const m1, const mDNSu8 *const m2, int len);
extern int DNSSECCanonicalOrder(const domainname *const d1, const domainname *const d2, int *subdomain);
extern void ProveInsecure(mDNS *const m, DNSSECVerifier *dv, InsecureContext *ic, domainname *trigger);
extern void BumpDNSSECStats(mDNS *const m, DNSSECStatsAction action, DNSSECStatsType type, mDNSu32 value);
extern char *DNSSECStatusName(DNSSECStatus status);
// DNSSECProbe belongs in DNSSECSupport.h but then we don't want to expose yet another plaform specific dnssec file
// to other platforms where dnssec is not supported.
extern void DNSSECProbe(mDNS *const m);
#endif // __DNSSEC_H
