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path: root/src/resolve/resolved-dns-dnssec.h
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2015-12-10resolved: chase DNSKEY/DS RRs when doing look-ups with DNSSEC enabledLennart Poettering
This adds initial support for validating RRSIG/DNSKEY/DS chains when doing lookups. Proof-of-non-existance, or proof-of-unsigned-zones is not implemented yet. With this change DnsTransaction objects will generate additional DnsTransaction objects when looking for DNSKEY or DS RRs to validate an RRSIG on a response. DnsTransaction objects are thus created for three reasons now: 1) Because a user asked for something to be resolved, i.e. requested by a DnsQuery/DnsQueryCandidate object. 2) As result of LLMNR RR probing, requested by a DnsZoneItem. 3) Because another DnsTransaction requires the requested RRs for validation of its own response. DnsTransactions are shared between all these users, and are GC automatically as soon as all of these users don't need a specific transaction anymore. To unify the handling of these three reasons for existance for a DnsTransaction, a new common naming is introduced: each DnsTransaction now tracks its "owners" via a Set* object named "notify_xyz", containing all owners to notify on completion. A new DnsTransaction state is introduced called "VALIDATING" that is entered after a response has been receieved which needs to be validated, as long as we are still waiting for the DNSKEY/DS RRs from other DnsTransactions. This patch will request the DNSKEY/DS RRs bottom-up, and then validate them top-down. Caching of RRs is now only done after verification, so that the cache is not poisoned with known invalid data. The "DnsAnswer" object gained a substantial number of new calls, since we need to add/remove RRs to it dynamically now.
2015-12-03resolved: introduce a dnssec_mode setting per scopeLennart Poettering
The setting controls which kind of DNSSEC validation is done: none at all, trusting the AD bit, or client-side validation. For now, no validation is implemented, hence the setting doesn't do much yet, except of toggling the CD bit in the generated messages if full client-side validation is requested.
2015-12-03resolved: don't accept expired RRSIGsLennart Poettering
2015-12-02resolved: add basic DNSSEC supportLennart Poettering
This adds most basic operation for doing DNSSEC validation on the client side. However, it does not actually add the verification logic to the resolver. Specifically, this patch only includes: - Verifying DNSKEY RRs against a DS RRs - Verifying RRSets against a combination of RRSIG and DNSKEY RRs - Matching up RRSIG RRs and DNSKEY RRs - Matching up RR keys and RRSIG RRs - Calculating the DNSSEC key tag from a DNSKEY RR All currently used DNSSEC combinations of SHA and RSA are implemented. Support for MD5 hashing and DSA or EC cyphers are not. MD5 and DSA are probably obsolete, and shouldn't be added. EC should probably be added eventually, if it actually is deployed on the Internet.