Bonjour, Coming back on the subject of « Reserved IP addresses ».
The proposed definition relies on the misleading definition of « Global » that was corrected between RFC6890 and RFC8190. In the new definition, it was changed to « Globally Reachable », and clause 2.1 of RFC8190 distinguishes between global in terms of allocation scope and global in terms of routing/reachability. The table only retains the later definition, and provides no indication regarding the unique allocation. Examining the different address ranges listed as « Globally Reachable » != False requires the reading of the RFCs reserving them. RFC7723 and RFC8155 makes it clear that the allocated addresses for these protocols are not globally unique; they’re any cast addresses used for discovery purposes. RFC7534 and 7535 are about DNS requests for purely internal addresses. Any ISP is free to participate, by configuring a DNS server that provides authoritative answers for RFC1918 addresses from empty zones, make it listen to the allocated addresses (the whole /24 —IPv4— or /48 —IPv6— is reserved, but only a few addresses are really used) and announce the availability of these ranges through BGP. The goal is to avoid DNS reverse lookups for RFC1918 addresses to propagate to the public DNS. This means that the allocated addresses are not globally unique. RFC7450 defines a protocol to allow tunneling multicast from a source to a destination over a unicast network. The /24 —IPv4— and /32 —IPv6— allocated ranges are used for the discovery of relays of this protocol, and these ranges can be announced by anybody using BGP. Therefore, they are not globally unique. So all ranges listed in iana-ipv4-special-registry.xhtml are to be considered as Reserved. However, this list is not complete, as it leaves out the whole 224.0.0.0/4 range which is dedicated to multicast and can not be considered globally unique. The iana-ipv6-special-registry.xhtml registry contains several more ranges, 2 of them with a Globally Reachable value that is not a boolean. RFC3056 is the 6to4 mechanism. It reserves the 2002::/16 range, with the goal that resulting addresses are globally unique, but not all possible addresses are valid. The next 4 octets after the 2002::/16 prefix is supposed to be a valid and globally unique IPv4 address. This in fact references our Reserved IP(v4) definition, in the way that 2002:0a00:0001::/48 is not a valid range either (the IPv4 address contained is 10.0.0.1). RFC4380 is another IPv6 over IPv4 tunneling mechanism called TEREDO, and allows for IPv6 over IPv4 communications behind NATs. An IPv6 address being built from the 2001::/32 prefix, the TEREDO server IPv4 address, and the IPv4 address of the TEREDO client (an obfuscated one), it can’t be globally unique (NAT mechanisms come into play here). RFC6052 presents an IPv4 address to IPv6 address translation mechanism, and defines a 96bits long prefix reserved for this. The IPv4 address is appended to this prefix, resulting in a supposedly globally unique IPv6 address. Again, since private IPv4 addresses MUST NOT be used with this specific prefix, some addresses are invalid, such as 64:ff9b::0a00:0001. RFC7954 reserves an IPv6 range for an experiment that should span on a 3/6 years period (LISP, see RFCs 6830 to 6837), defining new routing mechanisms, new address constructions, etc (as if IPv6 were not already complicated enough). The subject is vast, and I *think* the addresses taken from the 2001:5::/32 are thought to be globally unique (there’s a registry for that), so that could fit our definition of « non reserved »/« controlled » IP address. RFC7343 defines identifiers that look like IPv6 addresses, but are designed to not be IP-routable, cryptographically built, statistically unique. As these are not real IP addresses, we don’t have adequate verification mechanisms for that, and the question of their appearance in a public certificate may not be valid. So all ranges listed in iana-ipv6-special-registry.xhtml (except maybe one) are to be considered as Reserved. And again, this list is not complete, it leaves out most of 0::/3 and 8000::/1, and the whole 4000::/2 range. Less than 1% of the IPv6 address space is listed in this registry, while 87.50% of the IPv6 address space is currently reserved. Overall, even if the current definition requires a CA to look into numerous footnotes to find out if an IP address is Reserved or not, I think that the proposed definition is more error-prone than the current one. Cordialement, Erwann Abalea Le 27 juil. 2017 à 21:03, Erwann Abalea via Public <[email protected]<mailto:[email protected]>> a écrit : Bonjour, Right now, I’m not convinced by the proposed definition, because in that registry, at least 192.0.0.9/32 is listed as « Globally Reachable: True », so could be considered as non-Internal IP address by our definition and be present in a certificate, but in fact this IP address is used for PCP discovery, so is not globally unique, and can’t possibly be claimed as owned by anyone. Thus, I don’t think that the « Globally Reachable: False » is a valid discriminant for our purpose. I have yet to read the other RFCs mentioned in this registry, that go into foreign territories :/ (thanks for the effort, by the way) Cordialement, Erwann Abalea Le 27 juil. 2017 à 14:23, Peter Bowen <[email protected]<mailto:[email protected]>> a écrit : Tim and Erwann, I agree with Tim. I think the IP Address situation is similar to Internal Domain Names. We know what is _not_ global pretty well, so we have a definition for Internal Name and explicitly say you cannot have those in certificates. On the IP Address side, the current language for IPv6 does not parallel this. Notably the definitions point to data tables that focus on regional Internet registry (RIR) allocations. Reservations smaller than /8 for IPv4 and smaller than /10 for IPv6 are only noted in foot notes. Further, some IP addresses that are global in nature are listed as “reserved” because they are not allocated via the RIR system. Notably, the 6to4 address are “reserved” in IPv6 because they are allocated via the IPv4 allocation system. What would you think about changing the BRs to define Internal IP Address and then use that definition in the one place where Reserved IP Address is used: Internal IP Address: An IPv4 or IPv6 address that cannot be verified as globally unique within the public Internet at the time of certificate issuance because the IANA has "False" for Globally Reachable in either of the IANA Special-Purpose IP Address Registries: https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml or https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml Subject Alternative Name Extension Contents: This extension MUST contain at least one entry. Each entry MUST be one of the following types: […] iPAddress: the entry MUST contain an IP address that the CA has validated in accordance with Section 3.2.2.5. The entry MUST NOT contain an Internal IP Address. The Internal IP Address definition is parallels to the existing Internal Name definition: Internal Name: A string of characters (not an IP address) in a Common Name or Subject Alternative Name field of a Certificate that cannot be verified as globally unique within the public DNS at the time of certificate issuance because it does not end with a Top Level Domain registered in IANA’s Root Zone Database. What do you think? Thanks, Peter On Jul 26, 2017, at 9:03 AM, Tim Hollebeek <[email protected]<mailto:[email protected]>> wrote: I think the definition is the wrong place to handle reserved IPs. What should be true (though I haven’t checked that it actually is) is that it should be impossible to validate an IP that it is impossible to own. Any necessary improvements to provide that assurance should go in the validation methods. -Tim From: Public [mailto:[email protected]] On Behalf Of Peter Bowen via Public Sent: Tuesday, July 25, 2017 3:02 PM To: Erwann Abalea <[email protected]<mailto:[email protected]>>; CA/Browser Forum Public Discussion List <[email protected]<mailto:[email protected]>> Subject: Re: [cabfpub] Ballot 202 - Underscore and Wildcard Characters Erwann, Thank you for your detailed feedback and I appreciate you providing context for your vote. With regards to reserved IP addresses, the definition in the current BRs allows a CA to deliver a certificate for 192.0.0.9. They also allow a CA to deliver a certificate for 192.168.1.1. This is because the current language (which has been in the BRs since at least V1) says “Reserved IP Address” is only defined by the whole /8 being reserved. This means only 0/8, 10/8, 127/8 and 224/3 are currently Reserved IP v4 addresses. While I agree we may be able to further restrict issuance, this ballot covers the common cases. The ballot references RFC 5890 section 2.2 for the definition of Domain Label. This RFC is very specific on allowed characters; it is not any character. Notably your example is not valid because ‘*’ (0x2a) is a DISALLOWED character. RFC 5890 points to RFC 5892 for the full list; https://tools.ietf.org/html/rfc5892#appendix-B.1<https://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrXMz9RfRNA&s=5&u=https%3a%2f%2ftools%2eietf%2eorg%2fhtml%2frfc5892%23appendix-B%2e1> shows that the only ASCII characters that are allowed are hyphen-minus, digit 0 to digit 9, and letter a to letter z. Therefore *.*.domain.com<http://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrX8zp0SDNQ&s=5&u=http%3a%2f%2fdomain%2ecom> is not a valid Wildcard Domain Name according to the definition in ballot 202. Thanks, Peter On Jul 25, 2017, at 11:39 AM, Erwann Abalea via Public <[email protected]<mailto:[email protected]>> wrote: Bonsoir, DocuSign France votes No. While there are good clarifications around domain names, FQDNs, wildcards, and reserved labels, there are a few drawbacks: 1. Underscores in SAN:dNSName entries. It’s not the current BR that disallows underscores in dNSNames, it’s X.509 and RFC5280 (and current DNS specifications), and there is no justification about allowing underscores other than « it’s done by some admins » or « Microsoft allows it ». While domain names can contain anything (even characters such as '[({*$!?" ), dNSName shall contain a host name, and host names shall only be composed of LDH labels. I’d prefer the standards to be changed instead of explicitly allowing deviations from the standard. 2. « Reserved IP address ». The new definition now allows a CA to deliver a certificate for an obviously invalid IP (I doubt anyone could claim « owning » 192.0.0.9 or 192.0.0.10, and I haven’t fully checked the others). 3. « Wildcard Domain Name ». The new definition is not robust enough. An FQDN is a sequence of Domain Labels —which can contain any character—, so « *.domain.com<http://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrXxmp0HaOg&s=5&u=http%3a%2f%2fdomain%2ecom%2f> » is a valid FQDN, so « *.*.domain.com<http://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrXxmp0HaOg&s=5&u=http%3a%2f%2fdomain%2ecom%2f> » is a valid Wildcard Domain Name according to this definition. Cordialement, Erwann Abalea Le 12 juil. 2017 à 19:24, Ben Wilson via Public <[email protected]<mailto:[email protected]>> a écrit : Ballot 202 - Underscore and Wildcard Characters The current Baseline Requirements do not expressly allow underscore characters in Subject Alternative Names. This ballot seeks to clarify that one or more underscore characters (“_”) are allowed in FQDNs. In many places it also replaces the term "FQDN" with "Domain Name" because "Domain Name" now means either "FQDN" or "Wildcard Domain Name". The ballot clarifies validation of wildcard domain names. It also cleans up some of the language in Sections 3.2.2.4 and 7.1.4.2.1 of the Baseline Requirements. The following motion has been proposed by Ben Wilson of DigiCert and endorsed by Peter Bowen of Amazon and Ryan Sleevi of Google to introduce new Final Maintenance Guidelines for the "Baseline Requirements Certificate Policy for the Issuance and Management of Publicly-Trusted Certificates" (Baseline Requirements). --Motion Begins-- A. In Sections 1.3.2, 1.6 (Base Domain Name), 2.2, 3.2.2.4, 3.2.2.4.5, 3.2.2.4.6, 3.2.2.4.10, 3.2.2.4.11, 4.2.1, 4.9.1.1.6, and 4.9.11 of the Baseline Requirements, REPLACE the words "Fully Qualified Domain Name" and "FQDN" with "Domain Name". B. In Section 1.6.1 of the Baseline Requirements, REPLACE the definition for "Authorization Domain Name" with the following: The Domain Name used to obtain authorization for certificate issuance for a given Domain Name. The CA may use the FQDN returned from a DNS CNAME lookup as the Domain Name for the purposes of domain validation. If the Domain Name is a Wildcard Domain Name, then the CA MUST remove “*.” from the left most portion of requested Domain Name. The CA may prune zero or more labels from left to right until encountering a Base Domain Name and may use any one of the intermediate values for the purpose of domain validation. C. In Section 1.6.1 of the Baseline Requirements, INSERT the following definition: "Domain Label: An individual component of a Domain Name." D. In Section 1.6.1 of the Baseline Requirements, REPLACE the definition for "Domain Name" with the following: A set of one or more Domain Labels, each separated by a single full stop character ("."). E. In Section 1.6.1 of the Baseline Requirements, REPLACE the definition for "Fully-Qualified Domain Name" with the following: A Domain Name that includes the Domain Labels of all superior nodes in the Internet Domain Name System. F. In Section 1.6.1 of the Baseline Requirements, REPLACE the definition for "Reserved IP Address" with the following: An IPv4 or IPv6 address that the IANA has "False" for Globally Reachable in either of the IANA Special-Purpose IP Address Registries: https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml<https://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrX878hXWbg&s=5&u=https%3a%2f%2fwww%2eiana%2eorg%2fassignments%2fiana-ipv4-special-registry%2fiana-ipv4-special-registry%2exhtml> or https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml<https://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrS80o0bUbg&s=5&u=https%3a%2f%2fwww%2eiana%2eorg%2fassignments%2fiana-ipv6-special-registry%2fiana-ipv6-special-registry%2exhtml> G. In Section 1.6.1 of the Baseline Requirements, REPLACE the definition for "Wildcard Certificate" with the following: A Certificate containing a Wildcard Domain Name in any of the Subject Alternative Names in the Certificate. H. In Section 1.6.1 of the Baseline Requirements, INSERT the following definition: "Wildcard Domain Name: A Domain Name consisting of a single asterisk character ("*") followed by a single full stop character (".") followed by a Fully-Qualified Domain Name." I. In Section 2.2 of the Baseline Requirements, INSERT the word "requested" in the fourth sentence between the words "processing CAA records for" and "Domain Names" so that it reads, "processing CAA records for requested Domain Names". J. REPLACE the second paragraph of Section 3.2.2.4 of the Baseline Requirements so that it reads, "The CA SHALL confirm that, as of the date the Certificate issues, the CA has validated each Domain Name listed in the Certificate using at least one of the methods listed below, or is within the Domain Namespace of a Fully Qualified Domain Name (FQDN) that has been validated using at least one of the methods listed below (not including the method defined in section 3.2.2.4.8)." K. REPLACE Section 3.2.2.6 of the Baseline Requirements in its entirety with: 3.2.2.6. Additional Validation for Wildcard Certificates Before issuing a Wildcard Certificate, the CA MUST establish and follow a documented procedure[^pubsuffix] that determines if the FQDN portion of any Wildcard Domain Name in the certificate is “registry-controlled” or is a “public suffix” (e.g. “*.com”, “*.co.uk<http://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrXMx90HRaA&s=5&u=http%3a%2f%2fco%2euk%2f>”, see RFC 6454 Section 8.2 for further explanation). If the FQDN portion of any Wildcard Domain Name in the certificate is "registry-controlled" or is a "public suffix", CAs MUST refuse issuance unless the applicant proves its rightful control of the entire Domain Namespace. (e.g. CAs MUST NOT issue "*.co.uk<http://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrXMx90HRaA&s=5&u=http%3a%2f%2fco%2euk%2f>" or "*.local", but MAY issue "*.example.com<http://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrX039RCEaw&s=5&u=http%3a%2f%2fexample%2ecom%2f>" to Example Co.). [^pubsuffix] Determination of what is “registry-controlled” versus the registerable portion of a Country Code Top-Level Domain Namespace is not standardized at the time of writing and is not a property of the DNS itself. Current best practice is to consult a “public suffix list” such as http://publicsuffix.org/<http://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrXg090aAbA&s=5&u=http%3a%2f%2fpublicsuffix%2eorg%2f> (PSL), and to retrieve a fresh copy regularly. If using the PSL, a CA SHOULD consult the "ICANN DOMAINS" section only, not the "PRIVATE DOMAINS" section. The PSL is updated regularly to contain new gTLDs delegated by ICANN, which are listed in the "ICANN DOMAINS" section. A CA is not prohibited from issuing a Wildcard Certificate to the Registrant of an entire gTLD, provided that control of the entire namespace is demonstrated in an appropriate way. L. REPLACE Section 7.1.4.2.1 of the Baseline Requirements in its entirety with: 7.1.4.2.1 Subject Alternative Name Extension Certificate Field: extensions:subjectAltName Required/Optional: Required Contents: This extension MUST contain at least one entry. Each entry MUST be one of the following types: 1. dNSName: the entry MUST contain either a Fully-Qualified Domain Name or Wildcard Domain Name that the CA has validated in accordance with section 3.2.2.4. FQDNs and the FQDN portion of Wildcard DNs must comply with RFC 5280 section 4.2.1.6 with the following exception: underscore characters ("_") are allowed in Domain Labels such that replacing all underscore characters with hyphen characters ("-") would result in a valid Domain Label. CAs MUST NOT include Domain Labels which have hyphens as the third and fourth characters unless the first character is "x" or "X", the second character is "n" or "N", and the fifth and later characters are a valid Punycode string. CAs MUST additionally validate that Wildcard DNs are consistent with section 3.2.2.6. The entry MUST NOT contain an Internal Name. 2. iPAddress: the entry MUST contain an IP address that the CA has validated in accordance with Section 3.2.2.5. The entry MUST NOT contain a Reserved IP Address. M. REPLACE subsection a. of Section 7.1.4.2.2 of the Baseline Requirements with: a. Certificate Field: subject:commonName (OID 2.5.4.3) Required/Optional: Deprecated (Discouraged, but not prohibited) Contents: If present, this field MUST contain a single IP address or Domain Name that is one of the values contained in the Certificate’s subjectAltName extension (see Section 7.1.4.2.1). When including a Domain Name in a common name, CAs MUST only use LDH labels as defined in RFC 5890 and MUST NOT use U-labels. When including an IPv6 address in a common name, CAs MUST use a format conforming to Section 4 or Section 5 of RFC 5952. When including an IPv4 address in a common name, CAs MUST encode the name as an IPv4Address as defined in RFC 3986. --Motion Ends-- The procedure for approval of this Final Maintenance Guideline ballot is as follows (exact start and end times may be adjusted to comply with applicable Bylaws and IPR Agreement): BALLOT 202 Status: Final Maintenance Guideline Start time (22:00 UTC) End time (22:00 UTC) Discussion (7 to 14 days) July 12, 2017 to July 19, 2017 Vote for approval (7 days) July 19, 2017 to July 26, 2017 If a vote of the Forum approves this ballot, the Chair will initiate a 30-day IPR Review Period by sending out an IPR Review Notice. After 30 days of announcing the IPR Review period by the Chair: (a) If Exclusion Notice(s) are filed, this ballot approval is rescinded and a PAG will be created; or (b) If no Exclusion Notices are filed, this ballot becomes effective at end of the IPR Review Period. From Bylaw 2.3: If the Draft Guideline Ballot is proposing a Final Maintenance Guideline, such ballot will include a redline or comparison showing the set of changes from the Final Guideline section(s) intended to become a Final Maintenance Guideline, and need not include a copy of the full set of guidelines. Such redline or comparison shall be made against the Final Guideline section(s) as they exist at the time a ballot is proposed, and need not take into consideration other ballots that may be proposed subsequently, except as provided in Bylaw Section 2.3(j). Votes must be cast by posting an on-list reply to this thread on the Public list. A vote in favor of the motion must indicate a clear 'yes' in the response. A vote against must indicate a clear 'no' in the response. A vote to abstain must indicate a clear 'abstain' in the response. Unclear responses will not be counted. The latest vote received from any representative of a voting member before the close of the voting period will be counted. Voting members are listed here: https://cabforum.org/members/<https://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrX87-xCDaQ&s=5&u=https%3a%2f%2fcabforum%2eorg%2fmembers%2f> In order for the motion to be adopted, two thirds or more of the votes cast by members in the CA category and greater than 50% of the votes cast by members in the browser category must be in favor. Quorum is half of the number of currently active Members, which is the average number of Member organizations that have participated in the previous three Forum-wide meetings (both teleconferences and face-to-face meetings). Under Bylaw 2.2(g), at least the required quorum number must participate in the ballot for the ballot to be valid, either by voting in favor, voting against, or abstaining. <Ballot 202.pdf>_______________________________________________ Public mailing list [email protected]<mailto:[email protected]> https://cabforum.org/mailman/listinfo/public<https://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrS9nphXVPQ&s=5&u=https%3a%2f%2fcabforum%2eorg%2fmailman%2flistinfo%2fpublic> _______________________________________________ Public mailing list [email protected]<mailto:[email protected]> https://cabforum.org/mailman/listinfo/public<https://scanmail.trustwave.com/?c=4062&d=p5X32Qr_zIUD13y_r60xG76m2QwsjGNKrS9nphXVPQ&s=5&u=https%3a%2f%2fcabforum%2eorg%2fmailman%2flistinfo%2fpublic> _______________________________________________ Public mailing list [email protected]<mailto:[email protected]> https://cabforum.org/mailman/listinfo/public
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