From cca5e0b8a430c888c5de1b5d36b87c085354f2c8 Mon Sep 17 00:00:00 2001 From: Konstantin Ryabitsev Date: Wed, 26 Jun 2019 11:49:42 -0600 Subject: [PATCH] Documentation: PGP: update for newer HW devices Newer devices like Yubikey 5 and Nitrokey Pro 2 have added support for NISTP's implementation of ECC cryptography, so update the guide accordingly and add a note on when to use nistp256 and when to use ed25519 for generating S keys. Signed-off-by: Konstantin Ryabitsev Signed-off-by: Jonathan Corbet --- .../process/maintainer-pgp-guide.rst | 31 ++++++++++--------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/Documentation/process/maintainer-pgp-guide.rst b/Documentation/process/maintainer-pgp-guide.rst index 4bab7464ff8c..17db11b7ed48 100644 --- a/Documentation/process/maintainer-pgp-guide.rst +++ b/Documentation/process/maintainer-pgp-guide.rst @@ -238,7 +238,10 @@ your new subkey:: work. If for some reason you prefer to stay with RSA subkeys, just replace - "ed25519" with "rsa2048" in the above command. + "ed25519" with "rsa2048" in the above command. Additionally, if you + plan to use a hardware device that does not support ED25519 ECC + keys, like Nitrokey Pro or a Yubikey, then you should use + "nistp256" instead or "ed25519." Back up your master key for disaster recovery @@ -432,23 +435,23 @@ Available smartcard devices Unless all your laptops and workstations have smartcard readers, the easiest is to get a specialized USB device that implements smartcard -functionality. There are several options available: +functionality. There are several options available: - `Nitrokey Start`_: Open hardware and Free Software, based on FSI - Japan's `Gnuk`_. Offers support for ECC keys, but fewest security - features (such as resistance to tampering or some side-channel - attacks). -- `Nitrokey Pro`_: Similar to the Nitrokey Start, but more - tamper-resistant and offers more security features, but no ECC - support. -- `Yubikey 4`_: proprietary hardware and software, but cheaper than + Japan's `Gnuk`_. One of the few available commercial devices that + support ED25519 ECC keys, but offer fewest security features (such as + resistance to tampering or some side-channel attacks). +- `Nitrokey Pro 2`_: Similar to the Nitrokey Start, but more + tamper-resistant and offers more security features. Pro 2 supports ECC + cryptography (NISTP). +- `Yubikey 5`_: proprietary hardware and software, but cheaper than Nitrokey Pro and comes available in the USB-C form that is more useful with newer laptops. Offers additional security features such as FIDO - U2F, but no ECC. + U2F, among others, and now finally supports ECC keys (NISTP). `LWN has a good review`_ of some of the above models, as well as several -others. If you want to use ECC keys, your best bet among commercially -available devices is the Nitrokey Start. +others. Your choice will depend on cost, shipping availability in your +geographical region, and open/proprietary hardware considerations. .. note:: @@ -457,8 +460,8 @@ available devices is the Nitrokey Start. Foundation. .. _`Nitrokey Start`: https://shop.nitrokey.com/shop/product/nitrokey-start-6 -.. _`Nitrokey Pro`: https://shop.nitrokey.com/shop/product/nitrokey-pro-3 -.. _`Yubikey 4`: https://www.yubico.com/product/yubikey-4-series/ +.. _`Nitrokey Pro 2`: https://shop.nitrokey.com/shop/product/nitrokey-pro-2-3 +.. _`Yubikey 5`: https://www.yubico.com/products/yubikey-5-overview/ .. _Gnuk: http://www.fsij.org/doc-gnuk/ .. _`LWN has a good review`: https://lwn.net/Articles/736231/ .. _`qualify for a free Nitrokey Start`: https://www.kernel.org/nitrokey-digital-tokens-for-kernel-developers.html