From ea648e70a989cca190cd7403fe892fd2dcc290b4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 5 May 2024 20:37:14 +0200 Subject: Adding upstream version 1:9.11.5.P4+dfsg. Signed-off-by: Daniel Baumann --- doc/arm/dnssec.xml | 286 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 286 insertions(+) create mode 100644 doc/arm/dnssec.xml (limited to 'doc/arm/dnssec.xml') diff --git a/doc/arm/dnssec.xml b/doc/arm/dnssec.xml new file mode 100644 index 0000000..de922dc --- /dev/null +++ b/doc/arm/dnssec.xml @@ -0,0 +1,286 @@ + + + +
DNSSEC, Dynamic Zones, and Automatic Signing + +
Converting from insecure to secure + +
+ Changing a zone from insecure to secure can be done in two + ways: using a dynamic DNS update, or the + auto-dnssec zone option. + For either method, you need to configure + named so that it can see the + K* files which contain the public and private + parts of the keys that will be used to sign the zone. These files + will have been generated by + dnssec-keygen. You can do this by placing them + in the key-directory, as specified in + named.conf: + + zone example.net { + type master; + update-policy local; + file "dynamic/example.net/example.net"; + key-directory "dynamic/example.net"; + }; + + If one KSK and one ZSK DNSKEY key have been generated, this + configuration will cause all records in the zone to be signed + with the ZSK, and the DNSKEY RRset to be signed with the KSK as + well. An NSEC chain will be generated as part of the initial + signing process. +
Dynamic DNS update method + +
+ To insert the keys via dynamic update: + + % nsupdate + > ttl 3600 + > update add example.net DNSKEY 256 3 7 AwEAAZn17pUF0KpbPA2c7Gz76Vb18v0teKT3EyAGfBfL8eQ8al35zz3Y I1m/SAQBxIqMfLtIwqWPdgthsu36azGQAX8= + > update add example.net DNSKEY 257 3 7 AwEAAd/7odU/64o2LGsifbLtQmtO8dFDtTAZXSX2+X3e/UNlq9IHq3Y0 XtC0Iuawl/qkaKVxXe2lo8Ct+dM6UehyCqk= + > send + + While the update request will complete almost immediately, + the zone will not be completely signed until + named has had time to walk the zone and + generate the NSEC and RRSIG records. The NSEC record at the apex + will be added last, to signal that there is a complete NSEC + chain. + If you wish to sign using NSEC3 instead of NSEC, you should + add an NSEC3PARAM record to the initial update request. If you + wish the NSEC3 chain to have the OPTOUT bit set, set it in the + flags field of the NSEC3PARAM record. + + % nsupdate + > ttl 3600 + > update add example.net DNSKEY 256 3 7 AwEAAZn17pUF0KpbPA2c7Gz76Vb18v0teKT3EyAGfBfL8eQ8al35zz3Y I1m/SAQBxIqMfLtIwqWPdgthsu36azGQAX8= + > update add example.net DNSKEY 257 3 7 AwEAAd/7odU/64o2LGsifbLtQmtO8dFDtTAZXSX2+X3e/UNlq9IHq3Y0 XtC0Iuawl/qkaKVxXe2lo8Ct+dM6UehyCqk= + > update add example.net NSEC3PARAM 1 1 100 1234567890 + > send + + Again, this update request will complete almost + immediately; however, the record won't show up until + named has had a chance to build/remove the + relevant chain. A private type record will be created to record + the state of the operation (see below for more details), and will + be removed once the operation completes. + While the initial signing and NSEC/NSEC3 chain generation + is happening, other updates are possible as well. +
Fully automatic zone signing + +
+ To enable automatic signing, add the + auto-dnssec option to the zone statement in + named.conf. + auto-dnssec has two possible arguments: + allow or + maintain. + With + auto-dnssec allow, + named can search the key directory for keys + matching the zone, insert them into the zone, and use them to + sign the zone. It will do so only when it receives an + rndc sign <zonename>. + + + auto-dnssec maintain includes the above + functionality, but will also automatically adjust the zone's + DNSKEY records on schedule according to the keys' timing metadata. + (See and + for more information.) + + + named will periodically search the key directory + for keys matching the zone, and if the keys' metadata indicates + that any change should be made the zone, such as adding, removing, + or revoking a key, then that action will be carried out. By default, + the key directory is checked for changes every 60 minutes; this period + can be adjusted with the , up + to a maximum of 24 hours. The rndc loadkeys forces + named to check for key updates immediately. + + + If keys are present in the key directory the first time the zone + is loaded, the zone will be signed immediately, without waiting for an + rndc sign or rndc loadkeys + command. (Those commands can still be used when there are unscheduled + key changes, however.) + + + When new keys are added to a zone, the TTL is set to match that + of any existing DNSKEY RRset. If there is no existing DNSKEY RRset, + then the TTL will be set to the TTL specified when the key was + created (using the dnssec-keygen -L option), if + any, or to the SOA TTL. + + + If you wish the zone to be signed using NSEC3 instead of NSEC, + submit an NSEC3PARAM record via dynamic update prior to the + scheduled publication and activation of the keys. If you wish the + NSEC3 chain to have the OPTOUT bit set, set it in the flags field + of the NSEC3PARAM record. The NSEC3PARAM record will not appear in + the zone immediately, but it will be stored for later reference. When + the zone is signed and the NSEC3 chain is completed, the NSEC3PARAM + record will appear in the zone. + + Using the + auto-dnssec option requires the zone to be + configured to allow dynamic updates, by adding an + allow-update or + update-policy statement to the zone + configuration. If this has not been done, the configuration will + fail. +
Private-type records + +
+ The state of the signing process is signaled by + private-type records (with a default type value of 65534). When + signing is complete, these records will have a nonzero value for + the final octet (for those records which have a nonzero initial + octet). + The private type record format: If the first octet is + non-zero then the record indicates that the zone needs to be + signed with the key matching the record, or that all signatures + that match the record should be removed. + + + + algorithm (octet 1) + key id in network order (octet 2 and 3) + removal flag (octet 4) + complete flag (octet 5) + + + Only records flagged as "complete" can be removed via + dynamic update. Attempts to remove other private type records + will be silently ignored. + If the first octet is zero (this is a reserved algorithm + number that should never appear in a DNSKEY record) then the + record indicates changes to the NSEC3 chains are in progress. The + rest of the record contains an NSEC3PARAM record. The flag field + tells what operation to perform based on the flag bits. + + + + 0x01 OPTOUT + 0x80 CREATE + 0x40 REMOVE + 0x20 NONSEC + + +
DNSKEY rollovers + +
+ As with insecure-to-secure conversions, rolling DNSSEC + keys can be done in two ways: using a dynamic DNS update, or the + auto-dnssec zone option. +
Dynamic DNS update method + +
+ To perform key rollovers via dynamic update, you need to add + the K* files for the new keys so that + named can find them. You can then add the new + DNSKEY RRs via dynamic update. + named will then cause the zone to be signed + with the new keys. When the signing is complete the private type + records will be updated so that the last octet is non + zero. + If this is for a KSK you need to inform the parent and any + trust anchor repositories of the new KSK. + You should then wait for the maximum TTL in the zone before + removing the old DNSKEY. If it is a KSK that is being updated, + you also need to wait for the DS RRset in the parent to be + updated and its TTL to expire. This ensures that all clients will + be able to verify at least one signature when you remove the old + DNSKEY. + The old DNSKEY can be removed via UPDATE. Take care to + specify the correct key. + named will clean out any signatures generated + by the old key after the update completes. +
Automatic key rollovers + +
+ When a new key reaches its activation date (as set by + dnssec-keygen or dnssec-settime), + if the auto-dnssec zone option is set to + maintain, named will + automatically carry out the key rollover. If the key's algorithm + has not previously been used to sign the zone, then the zone will + be fully signed as quickly as possible. However, if the new key + is replacing an existing key of the same algorithm, then the + zone will be re-signed incrementally, with signatures from the + old key being replaced with signatures from the new key as their + signature validity periods expire. By default, this rollover + completes in 30 days, after which it will be safe to remove the + old key from the DNSKEY RRset. +
NSEC3PARAM rollovers via UPDATE + +
+ Add the new NSEC3PARAM record via dynamic update. When the + new NSEC3 chain has been generated, the NSEC3PARAM flag field + will be zero. At this point you can remove the old NSEC3PARAM + record. The old chain will be removed after the update request + completes. +
Converting from NSEC to NSEC3 + +
+ To do this, you just need to add an NSEC3PARAM record. When + the conversion is complete, the NSEC chain will have been removed + and the NSEC3PARAM record will have a zero flag field. The NSEC3 + chain will be generated before the NSEC chain is + destroyed. +
Converting from NSEC3 to NSEC + +
+ To do this, use nsupdate to + remove all NSEC3PARAM records with a zero flag + field. The NSEC chain will be generated before the NSEC3 chain is + removed. +
Converting from secure to insecure + +
+ To convert a signed zone to unsigned using dynamic DNS, + delete all the DNSKEY records from the zone apex using + nsupdate. All signatures, NSEC or NSEC3 chains, + and associated NSEC3PARAM records will be removed automatically. + This will take place after the update request completes. + This requires the + dnssec-secure-to-insecure option to be set to + yes in + named.conf. + In addition, if the auto-dnssec maintain + zone statement is used, it should be removed or changed to + allow instead (or it will re-sign). + +
Periodic re-signing + +
+ In any secure zone which supports dynamic updates, named + will periodically re-sign RRsets which have not been re-signed as + a result of some update action. The signature lifetimes will be + adjusted so as to spread the re-sign load over time rather than + all at once. +
NSEC3 and OPTOUT + +
+ + named only supports creating new NSEC3 chains + where all the NSEC3 records in the zone have the same OPTOUT + state. + named supports UPDATES to zones where the NSEC3 + records in the chain have mixed OPTOUT state. + named does not support changing the OPTOUT + state of an individual NSEC3 record, the entire chain needs to be + changed if the OPTOUT state of an individual NSEC3 needs to be + changed. +
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