Since EC keys doesn't support encryption directly, we use ECDH protocol.
We generate a pair of EC keys in the same EC group, then derive a shared secret using the generated private key and the public key in the token.
The derived shared secret is used as a volume key. The generated public key is stored in the LUKS2 JSON token header area. The generated private key is erased.
To unlock a volume, we derive the shared secret with the stored public key and a private key in the token.
Co-authored-by: MkfsSion <mkfssion@mkfssion.com>
The header and keyfile are necessary only for opening the device, not
for closing, so it is not necessary to deactivate the generated
cryptsetup unit when the header or keyfile backing store are removed.
This is especially useful in the case of softreboot, when the new
mount root is setup under /run/nextroot/ but we don't want to close
the cryptsetup devices for encrypted /var/ or so, and we simply
mount it directly on /run/nextroot/var/ before the soft-reboot.
As pointed out in https://github.com/systemd/systemd/issues/29814, we need to
use phrases are are meaningful on their own, because the man page formatter
creates a list at the bottom. With <ulink>see docs</ulink>, we end up with:
NOTES:
1. see docs
https://some.url/page
2. see docs
https://some.url/page2
which is not very useful :(
Also, the text inside the tag should not include punctuation.
Python helper:
from xml_helper import xml_parse
for p in glob.glob('../man/*.xml'):
t = xml_parse(p)
ulinks = t.iterfind('.//ulink')
for ulink in ulinks:
if ulink.text is None: continue
text = ' '.join(ulink.text.split())
print(f'{p}: {text}')
As I noticed a lot of missing information when trying to implement checking
for missing info. I reimplemented the version information script to be more
robust, and here is the result.
Follow up to ec07c3c80b
This tries to add information about when each option was added. It goes
back to version 183.
The version info is included from a separate file to allow generating it,
which would allow more control on the formatting of the final output.
(s) is just ugly with a vibe of DOS. In most cases just using the normal plural
form is more natural and gramatically correct.
There are some log_debug() statements left, and texts in foreign licenses or
headers. Those are not touched on purpose.
In most cases we refernced the concept as "initrd". Let's convert most
remaining uses of "initramfs" to "initrd" too, to stay internally
consistent.
This leaves "initramfs" only where it's relevant to explain historical
concepts or where "initramfs" is part of the API (i.e. in
/run/initramfs).
Follow-up for: b66a6e1a58
Handle the case where TPM2 metadata is not available and explicitly
provided in crypttab. This adds a new "tpm2-pin" option to crypttab
options for this purpose.
Use the option name 'password-echo' instead of the generic term
'silent'.
Make the option take an argument for better control over echoing
behavior.
Related discussion in https://github.com/systemd/systemd/pull/19619
Previously, we supported only "," as separator. This adds support for
"+" and makes it the documented choice.
This is to make specifying PCRs in crypttab easier, since commas are
already used there for separating volume options, and needless escaping
sucks.
"," continues to be supported, but in order to keep things minimal not
documented.
Fixe: #19205
Adds a crypttab option 'silent' that enables the AskPasswordFlag
ASK_PASSWORD_SILENT. This allows usage of systemd-cryptsetup to default
to silent mode, rather than requiring the user to press tab every time.
