Hi, Here's third version of the patches. I've incorporated the feedback so far and reordered the patches (again) to restore their degree-of-compatibility order. The full text is included below.
Michał Górny (12): glep-0063: Use 'OpenPGP' as appropriate glep-0063: RSAv4 -> OpenPGP v4 key format glep-0063: 'Gentoo subkey' → 'Signing subkey' glep-0063: Root key → primary key glep-0063: Split out the signing subkey into a separation point glep-0063: Explain minimal & recommended sections glep-0063: Change the recommended RSA key size to 2048 bits glep-0063: Allow ECC curve 25519 keys glep-0063: Stop recommending DSA subkeys glep-0063: Make 2-yearly expiration term mandatory glep-0063: Require renewal 2 weeks before expiration glep-0063: Disallow using DSA keys glep-0063.rst | 97 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 64 insertions(+), 33 deletions(-) --- GLEP: 63 Title: Gentoo OpenPGP policies Author: Robin H. Johnson <robb...@gentoo.org>, Andreas K. Hüttel <dilfri...@gentoo.org>, Marissa Fischer <blogtodif...@gmail.com> Type: Standards Track Status: Final Version: 2 Created: 2013-02-18 Last-Modified: 2018-07-05 Post-History: 2013-11-10 Content-Type: text/x-rst --- Credits ======= Many developers and external sources helped in this GLEP. Abstract ======== This GLEP provides both a minimum requirement and a recommended set of OpenPGP key management policies for the Gentoo Linux distribution. Changes ======= v2 The distinct minimal and recommended expirations have been replaced by a single requirement. The rules have been simplified to use the same time of 2 years for both the primary key and subkeys. An additional rule requesting key renewal 2 weeks before expiration has been added. This is in order to give services and other developers time to refresh the key. The usage of DSA keys has been disallowed. v1.1 The recommended RSA key size has been changed from 4096 bits to 2048 bits to match the GnuPG recommendations [#GNUPG-FAQ-11-4]_. The larger recommendation was unjustified and resulted in people unnecessarily replacing their RSA-2048 keys. Minimal specification has been amended to allow for ECC keys. The option of using DSA subkey has been removed from recommendations. The section now specifies a single recommendation of using RSA. Motivation ========== Given the increasing use and importance of cryptographic protocols in internet transactions of any kind, unified requirements for OpenPGP keys used in Gentoo Linux development are sorely needed. This document provides both a set of bare minimum requirements and a set of best practice recommendations for the use of GnuPG (or other OpenPGP providers) by Gentoo Linux developers. It is intended to provide a basis for future improvements such as, e.g., consistent ebuild or package signing and verifying by end users. Specifications for OpenPGP keys =============================== Bare minimum requirements ------------------------- This section specifies obligatory requirements for all OpenPGP keys used to commit to Gentoo. Keys that do not conform to those requirements can not be used to commit. 1. SHA2-series output digest (SHA1 digests internally permitted), 256bit or more:: personal-digest-preferences SHA256 2. Signing subkey that is different from the primary key, and does not have any other capabilities enabled. 3. Primary key and the signing subkey are both of type EITHER: a. RSA, >=2048 bits (OpenPGP v4 key format or later only) b. ECC curve 25519 4. Expiration date on key and all subkeys set to at most 2 years 5. Key expiration date renewed at least 2 weeks before the previous expiration date. 6. Upload your key to the SKS keyserver rotation before usage! Recommendations --------------- This section specifies the best practices for Gentoo developers. The developers should follow those practices unless there is a strong technical reason not to (e.g. hardware limitations, necessity of replacing their primary key). 1. Copy ``/usr/share/gnupg/gpg-conf.skel`` to ``~/.gnupg/gpg.conf``, append the following block:: keyserver pool.sks-keyservers.net emit-version default-recipient-self # -- All of the below portion from the RiseUp.net OpenPGP best practices, and # -- many of them are also in the Debian GPG documentation. # when outputting certificates, view user IDs distinctly from keys: fixed-list-mode # long keyids are more collision-resistant than short keyids (it's trivial to make a key # with any desired short keyid) # NOTE: this breaks kmail gnupg support! keyid-format 0xlong # when multiple digests are supported by all recipients, choose the strongest one: personal-digest-preferences SHA512 SHA384 SHA256 SHA224 # preferences chosen for new keys should prioritize stronger algorithms: default-preference-list SHA512 SHA384 SHA256 SHA224 AES256 AES192 AES CAST5 BZIP2 ZLIB ZIP Uncompressed # If you use a graphical environment (and even if you don't) you should be using an agent: # (similar arguments as https://www.debian-administration.org/users/dkg/weblog/64) use-agent # You should always know at a glance which User IDs gpg thinks are legitimately bound to # the keys in your keyring: verify-options show-uid-validity list-options show-uid-validity # include an unambiguous indicator of which key made a signature: # (see http://thread.gmane.org/gmane.mail.notmuch.general/3721/focus=7234) # (and http://www.ietf.org/mail-archive/web/openpgp/current/msg00405.html) sig-notation issuer-...@notations.openpgp.fifthhorseman.net=%g # when making an OpenPGP certification, use a stronger digest than the default SHA1: cert-digest-algo SHA256 2. Primary key and the signing subkey are both of type RSA, 2048 bits (OpenPGP v4 key format or later) 3. Key expiration renewed annually 4. Create a revocation certificate & store it hardcopy offsite securely (it's about ~300 bytes). 5. Encrypted backup of your secret keys. Gentoo LDAP =========== All Gentoo developers must list the complete fingerprint for their primary keys in the "``gpgfingerprint``" LDAP field. It must be exactly 40 hex digits, uppercase, with optional spaces every 8 hex digits. Regular expression for validation:: ^([[:space:]]*[[:xdigit:]]{8}){5}$ The prior "``gpgkey``" field will be removed, as it is a subset of the fingerprint field. In any place that presently displays the "``gpgkey``" field, the last 16 hex digits of the fingerprint should be displayed instead. Backwards Compatibility ======================= There is no consistent standard for GPG usage in Gentoo to date. There is conflicting information in the Devmanual [#DEVMANUAL-MANIFEST]_ and the GnuPG Gentoo user guide [#GNUPG-USER]_. As there is little enforcement of Manifest signing and very little commit signing to date, there are no backwards compatibility concerns. External documentation ====================== Much of the above was driven by the following: * NIST SP 800-57 recommendations [#NISTSP800571]_, [#NISTSP800572]_ * Debian GPG documentation [#DEBIANGPG]_ * RiseUp.net OpenPGP best practices [#RISEUP]_ * ENISA Algorithms, Key Sizes and Parameters Report 2013 [#ENISA2013]_ References ========== .. [#GNUPG-FAQ-11-4] GnuPG FAQ: Why doesn’t GnuPG default to using RSA-4096? (https://www.gnupg.org/faq/gnupg-faq.html#no_default_of_rsa4096) .. [#DEBIANGPG] Debian GPG documentation (https://wiki.debian.org/Keysigning) .. [#EKAIA] Ana's blog: Creating a new GPG key (http://ekaia.org/blog/2009/05/10/creating-new-gpgkey/) .. [#RISEUP] RiseUp.net OpenPGP best practices (https://help.riseup.net/en/security/message-security/openpgp/best-practices) .. [#DEVMANUAL-MANIFEST] Gentoo Development Guide: Manifest (http://devmanual.gentoo.org/general-concepts/manifest/index.html) .. [#GNUPG-USER] GnuPG Gentoo User Guide (http://www.gentoo.org/doc/en/gnupg-user.xml) .. [#NISTSP800571] NIST SP 800-57: Recommendation for Key Management: Part 1: General (Revision 3) (http://csrc.nist.gov/publications/nistpubs/800-57/sp800-57_part1_rev3_general.pdf) .. [#NISTSP800572] NIST SP 800-57: Recommendation for Key Management: Part 2: Best Practices for Key Management Organization (http://csrc.nist.gov/publications/nistpubs/800-57/SP800-57-Part2.pdf) .. [#ISSUER-ANNOTATE] Including the entire fingerprint of the issuer in an OpenPGP certification (http://thread.gmane.org/gmane.mail.notmuch.general/3721/focus=7234) .. [#ENISA2013] ENISA Algorithms, Key Sizes and Parameters Report, 2013 recommendations, version 1.0 (October 2013) (https://www.enisa.europa.eu/activities/identity-and-trust/library/deliverables/algorithms-key-sizes-and-parameters-report) Copyright ========= Copyright (c) 2013 by Robin Hugh Johnson, Andreas K. Hüttel, Marissa Fischer. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/. -- Best regards, Michał Górny -- 2.18.0