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Qubes OS
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A reasonably secure operating system for personal computers.

Qubes-OS.org

⚠️This channel is updated after devs make an announcement to the project.

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Canaries provide an important indication about the security status of the project. If the canary is healthy, it’s a strong sign that things are running normally. However, if the canary is unhealthy, it could mean that the project or its members are being coerced in some way.

What are some signs of an unhealthy canary?

Here is a non-exhaustive list of examples:


Dead canary. In each canary, we state a window of time during which you should expect the next canary to be published. If no canary is published within that window of time and no good explanation is provided for missing the deadline, then the canary has died.
Missing statement(s). Every canary contains the same set of statements (sometimes along with special announcements, which are not the same in every canary). If an important statement was present in older canaries but suddenly goes missing from new canaries with no correction or explanation, then this may be an indication that the signers can no longer truthfully make that statement.
Missing signature(s). Qubes canaries are signed by the members of the Qubes security team (https://www.qubes-os.org/security/#qubes-security-team) (see below). If one of them has been signing all canaries but suddenly and permanently stops signing new canaries without any explanation, then this may indicate that this person is under duress or can no longer truthfully sign the statements contained in the canary.


Does every unexpected or unusual occurrence related to a canary indicate something bad?

No, there are many canary-related possibilities that should not worry you. Here is a non-exhaustive list of examples:


Unusual reposts. The only canaries that matter are the ones that are validly signed in the Qubes security pack (qubes-secpack) (https://www.qubes-os.org/security/pack/). Reposts of canaries (like the one in this announcement) do not have any authority (except insofar as they reproduce validly-signed text from the qubes-secpack). If the actual canary in the qubes-secpack is healthy, but reposts are late, absent, or modified on the website, mailing lists, forum, or social media platforms, you should not be concerned about the canary.
Last-minute signature(s). If the canary is signed at the last minute but before the deadline, that’s okay. (People get busy and procrastinate sometimes.)
Signatures at different times. If one signature is earlier or later than the other, but both are present within a reasonable period of time, that’s okay. (For example, sometimes one signer is out of town, but we try to plan the deadlines around this.)
Permitted changes. If something about a canary changes without violating any of statements in prior canaries, that’s okay. (For example, canaries are usually scheduled for the first fourteen days of a given month, but there’s no rule that says they have to be.)
Unusual but planned changes. If something unusual happens, but it was announced in advance, and the appropriate statements are signed, that’s okay (e.g., when Joanna left the security team and Simon joined it).


In general, it would not be realistic for an organization to exist that never changed, had zero turnover, and never made mistakes. Therefore, it would be reasonable to expect such events to occur periodically, and it would be unreasonable to regard every unusual or unexpected canary-related event as a sign of compromise. For example, if something usual happens with a canary, and we say it was a mistake and correct it, you will have to decide for yourself whether it’s more likely that it really was just a mistake or that something is wrong and that this is how we chose to send you a subtle signal about it. This will require you to think carefully about which among many possible scenarios is most likely given the evidence available to you. Since this is fundamentally a matter of judgment, canaries are ultimately a social scheme, not a technical one.

What are the PGP signatures that accompany canaries?
A PGP (https://en.wikipedia.org/wiki/Pretty_Good_Privacy) signature is a cryptographic digital signature (https://en.wikipedia.org/wiki/Digital_signature) made in accordance with the OpenPGP (https://en.wikipedia.org/wiki/Pretty_Good_Privacy#OpenPGP) standard. PGP signatures can be cryptographically verified with programs like GNU Privacy Guard (GPG) (https://en.wikipedia.org/wiki/GNU_Privacy_Guard). The Qubes security team cryptographically signs all canaries so that Qubes users have a reliable way to check whether canaries are genuine. The only way to be certain that a canary is authentic is by verifying its PGP signatures.

Why should I care whether a canary is authentic?

If you fail to notice that a canary is unhealthy or has died, you may continue to trust the Qubes security team even after they have signaled via the canary (or lack thereof) that they been compromised or coerced. Falsified canaries could include manipulated text designed to sow fear, uncertainty, and doubt about the security of Qubes OS or the status of the Qubes OS Project.

How do I verify the PGP signatures on a canary?

The following command-line instructions assume a Linux system with git and gpg installed. (For Windows and Mac options, see OpenPGP software (https://www.qubes-os.org/security/verifying-signatures/#openpgp-software).)



Obtain the Qubes Master Signing Key (QMSK), e.g.:

$ gpg --fetch-keys https://keys.qubes-os.org/keys/qubes-master-signing-key.asc
gpg: directory '/home/user/.gnupg' created
gpg: keybox '/home/user/.gnupg/pubring.kbx' created
gpg: requesting key from 'https://keys.qubes-os.org/keys/qubes-master-signing-key.asc'
gpg: /home/user/.gnupg/trustdb.gpg: trustdb created
gpg: key DDFA1A3E36879494: public key "Qubes Master Signing Key" imported
gpg: Total number processed: 1
gpg: imported: 1


(For more ways to obtain the QMSK, see How to import and authenticate the Qubes Master Signing Key (https://www.qubes-os.org/security/verifying-signatures/#how-to-import-and-authenticate-the-qubes-master-signing-key).)


View the fingerprint of the PGP key you just imported. (Note: gpg> indicates a prompt inside of the GnuPG program. Type what appears after it when prompted.)

$ gpg --edit-key 0x427F11FD0FAA4B080123F01CDDFA1A3E36879494
gpg (GnuPG) 2.2.27; Copyright (C) 2021 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.


pub rsa4096/DDFA1A3E36879494
created: 2010-04-01 expires: never usage: SC
trust: unknown validity: unknown
[ unknown] (1). Qubes Master Signing Key

gpg> fpr
pub rsa4096/DDFA1A3E36879494 2010-04-01 Qubes Master Signing Key
Primary key fingerprint: 427F 11FD 0FAA 4B08 0123 F01C DDFA 1A3E 3687 9494



Important: At this point, you still don’t know whether the key you just imported is the genuine QMSK or a forgery. In order for this entire procedure to provide meaningful security benefits, you must authenticate the QMSK out-of-band. Do not skip this step! The standard method is to obtain the QMSK fingerprint from multiple independent sources in several different ways and check to see whether they match the key you just imported. For more information, see How to import and authenticate the Qubes Master Signing Key (https://www.qubes-os.org/security/verifying-signatures/#how-to-import-and-authenticate-the-qubes-master-signing-key).

Tip: After you have authenticated the QMSK out-of-band to your satisfaction, record the QMSK fingerprint in a safe place (or several) so that you don’t have to repeat this step in the future.


Once you are satisfied that you have the genuine QMSK, set its trust level to 5 (“ultimate”), then quit GnuPG with q.

gpg> trust
pub rsa4096/DDFA1A3E36879494
created: 2010-04-01 expires: never usage: SC
trust: unknown validity: unknown
[ unknown] (1). Qubes Master Signing Key

Please decide how far you trust this user to correctly verify other users' keys
(by looking at passports, checking fingerprints from different sources, etc.)

1 = I don't know or won't say
2 = I do NOT trust
3 = I trust marginally
4 = I trust fully
5 = I trust ultimately
m = back to the main menu

Your decision? 5
Do you really want to set this key to ultimate trust? (y/N) y

pub rsa4096/DDFA1A3E36879494
created: 2010-04-01 expires: never usage: SC
trust: ultimate validity: unknown
[ unknown] (1). Qubes Master Signing Key
Please note that the shown key validity is not necessarily correct
unless you restart the program.

gpg> q



Use Git to clone the qubes-secpack repo.

$ git clone https://github.com/QubesOS/qubes-secpack.git
Cloning into 'qubes-secpack'...
remote: Enumerating objects: 4065, done.
remote: Counting objects: 100% (1474/1474), done.
remote: Compressing objects: 100% (742/742), done.
remote: Total 4065 (delta 743), reused 1413 (delta 731), pack-reused 2591
Receiving objects: 100% (4065/4065), 1.64 MiB | 2.53 MiB/s, done.
Resolving deltas: 100% (1910/1910), done.



Import the included PGP keys. (See our PGP key policies (https://www.qubes-os.org/security/pack/#pgp-key-policies) for important information about these keys.)

$ gpg --import qubes-secpack/keys/*/*
gpg: key 063938BA42CFA724: public key "Marek Marczykowski-Górecki (Qubes OS signing key)" imported
gpg: qubes-secpack/keys/core-devs/retired: read error: Is a directory
gpg: no valid OpenPGP data found.
gpg: key 8C05216CE09C093C: 1 signature not checked due to a missing key
gpg: key 8C05216CE09C093C: public key "HW42 (Qubes Signing Key)" imported
gpg: key DA0434BC706E1FCF: public key "Simon Gaiser (Qubes OS signing key)" imported
gpg: key 8CE137352A019A17: 2 signatures not checked due to missing keys
gpg: key 8CE137352A019A17: public key "Andrew David Wong (Qubes Documentation Signing Key)" imported
gpg: key AAA743B42FBC07A9: public key "Brennan Novak (Qubes Website & Documentation Signing)" imported
gpg: key B6A0BB95CA74A5C3: public key "Joanna Rutkowska (Qubes Documentation Signing Key)" imported
gpg: key F32894BE9684938A: public key "Marek Marczykowski-Górecki (Qubes Documentation Signing Key)" imported
gpg: key 6E7A27B909DAFB92: public key "Hakisho Nukama (Qubes Documentation Signing Key)" imported
gpg: key 485C7504F27D0A72: 1 signature not checked due to a missing key
gpg: key 485C7504F27D0A72: public key "Sven Semmler (Qubes Documentation Signing Key)" imported
gpg: key BB52274595B71262: public key "unman (Qubes Documentation Signing Key)" imported
gpg: key DC2F3678D272F2A8: 1 signature not checked due to a missing key
gpg: key DC2F3678D272F2A8: public key "Wojtek Porczyk (Qubes OS documentation signing key)" imported
gpg: key FD64F4F9E9720C4D: 1 signature not checked due to a missing key
gpg: key FD64F4F9E9720C4D: public key "Zrubi (Qubes Documentation Signing Key)" imported
gpg: key DDFA1A3E36879494: "Qubes Master Signing Key" not changed
gpg: key 1848792F9E2795E9: public key "Qubes OS Release 4 Signing Key" imported
gpg: qubes-secpack/keys/release-keys/retired: read error: Is a directory
gpg: no valid OpenPGP data found.
gpg: key D655A4F21830E06A: public key "Marek Marczykowski-Górecki (Qubes security pack)" imported
gpg: key ACC2602F3F48CB21: public key "Qubes OS Security Team" imported
gpg: qubes-secpack/keys/security-team/retired: read error: Is a directory
gpg: no valid OpenPGP data found.
gpg: key 4AC18DE1112E1490: public key "Simon Gaiser (Qubes Security Pack signing key)" imported
gpg: Total number processed: 17
gpg: imported: 16
gpg: unchanged: 1
gpg: marginals needed: 3 completes needed: 1 trust model: pgp
gpg: depth: 0 valid: 1 signed: 6 trust: 0-, 0q, 0n, 0m, 0f, 1u
gpg: depth: 1 valid: 6 signed: 0 trust: 6-, 0q, 0n, 0m, 0f, 0u



Verify signed Git tags.
$ cd qubes-secpack/
$ git tag -v `git describe`
object 266e14a6fae57c9a91362c9ac784d3a891f4d351
type commit
tag marmarek_sec_266e14a6
tagger Marek Marczykowski-Górecki 1677757924 +0100

Tag for commit 266e14a6fae57c9a91362c9ac784d3a891f4d351
gpg: Signature made Thu 02 Mar 2023 03:52:04 AM PST
gpg: using RSA key 2D1771FE4D767EDC76B089FAD655A4F21830E06A
gpg: Good signature from "Marek Marczykowski-Górecki (Qubes security pack)" [full]


The exact output will differ, but the final line should always start with gpg: Good signature from... followed by an appropriate key. The [full] indicates full trust, which this key inherits in virtue of being validly signed by the QMSK.


Verify PGP signatures, e.g.:

$ cd QSBs/
$ gpg --verify qsb-087-2022.txt.sig.marmarek qsb-087-2022.txt
gpg: Signature made Wed 23 Nov 2022 04:05:51 AM PST
gpg: using RSA key 2D1771FE4D767EDC76B089FAD655A4F21830E06A
gpg: Good signature from "Marek Marczykowski-Górecki (Qubes security pack)" [full]
$ gpg --verify qsb-087-2022.txt.sig.simon qsb-087-2022.txt
gpg: Signature made Wed 23 Nov 2022 03:50:42 AM PST
gpg: using RSA key EA18E7F040C41DDAEFE9AA0F4AC18DE1112E1490
gpg: Good signature from "Simon Gaiser (Qubes Security Pack signing key)" [full]
$ cd ../canaries/
$ gpg --verify canary-034-2023.txt.sig.marmarek canary-034-2023.txt
gpg: Signature made Thu 02 Mar 2023 03:51:48 AM PST
gpg: using RSA key 2D1771FE4D767EDC76B089FAD655A4F21830E06A
gpg: Good signature from "Marek Marczykowski-Górecki (Qubes security pack)" [full]
$ gpg --verify canary-034-2023.txt.sig.simon canary-034-2023.txt
gpg: Signature made Thu 02 Mar 2023 01:47:52 AM PST
gpg: using RSA key EA18E7F040C41DDAEFE9AA0F4AC18DE1112E1490
gpg: Good signature from "Simon Gaiser (Qubes Security Pack signing key)" [full]


Again, the exact output will differ, but the final line of output from each gpg --verify command should always start with gpg: Good signature from... followed by an appropriate key.



For this announcement (Qubes Canary 038), the commands are:

$ gpg --verify canary-038-2024.txt.sig.marmarek canary-038-2024.txt
$ gpg --verify canary-038-2024.txt.sig.simon canary-038-2024.txt


You can also verify the signatures directly from this announcement in addition to or instead of verifying the files from the qubes-secpack. Simply copy and paste the Qubes Canary 038 text into a plain text file and do the same for both signature files. Then, perform the same authentication steps as listed above, substituting the filenames above with the names of the files you just created.
XSAs released on 2024-03-12
https://www.qubes-os.org/news/2024/03/13/xsas-released-on-2024-03-12/

The Xen Project (https://xenproject.org/) has released one or more Xen security advisories (XSAs) (https://xenbits.xen.org/xsa/).
The security of Qubes OS is affected.

XSAs that DO affect the security of Qubes OS

The following XSAs do affect the security of Qubes OS:


XSA-452 (https://xenbits.xen.org/xsa/advisory-452.html)

See QSB-101 (https://www.qubes-os.org/news/2024/03/13/qsb-101/)




XSAs that DO NOT affect the security of Qubes OS

The following XSAs do not affect the security of Qubes OS, and no user action is necessary:


XSA-453 (https://xenbits.xen.org/xsa/advisory-453.html)

The Qubes security team concurs with the Xen security team’s assessment in the “VULNERABLE SYSTEMS” section of XSA-453.




About this announcement

Qubes OS uses the Xen hypervisor (https://wiki.xenproject.org/wiki/Xen_Project_Software_Overview) as part of its architecture (https://www.qubes-os.org/doc/architecture/). When the Xen Project (https://xenproject.org/) publicly discloses a vulnerability in the Xen hypervisor, they issue a notice called a Xen security advisory (XSA) (https://xenproject.org/developers/security-policy/). Vulnerabilities in the Xen hypervisor sometimes have security implications for Qubes OS. When they do, we issue a notice called a Qubes security bulletin (QSB) (https://www.qubes-os.org/security/qsb/). (QSBs are also issued for non-Xen vulnerabilities.) However, QSBs can provide only positive confirmation that certain XSAs do affect the security of Qubes OS. QSBs cannot provide negative confirmation that other XSAs do not affect the security of Qubes OS. Therefore, we also maintain an XSA tracker (https://www.qubes-os.org/security/xsa/), which is a comprehensive list of all XSAs publicly disclosed to date, including whether each one affects the security of Qubes OS. When new XSAs are published, we add them to the XSA tracker and publish a notice like this one in order to inform Qubes users that a new batch of XSAs has been released and whether each one affects the security of Qubes OS.
Qubes OS Summit 2024: September 20-22 in Berlin
https://www.qubes-os.org/news/2024/03/13/qubes-os-summit-2024/

In conjunction with 3mdeb (https://3mdeb.com/), the sixth edition of our Qubes OS Summit will be held live this year from September 20 to 22 in Berlin, Germany! For more information about this event, please see: https://vpub.dasharo.com/e/16/qubes-os-summit-2024

If you would like to submit a proposal, the Call for Participation (CFP) is open until August 5: https://cfp.3mdeb.com/qubes-os-summit-2023/cfp
QSB-101: Register File Data Sampling (XSA-452)
https://www.qubes-os.org/news/2024/03/13/qsb-101/

We have published Qubes Security Bulletin 101: Register File Data Sampling (XSA-452) (https://github.com/QubesOS/qubes-secpack/blob/main/QSBs/qsb-101-2024.txt). The text of this QSB and its accompanying cryptographic signatures are reproduced below. For an explanation of this announcement and instructions for authenticating this QSB, please see the end of this announcement.

Qubes Security Bulletin 101


---===[ Qubes Security Bulletin 101 ]===---

2024-03-12

Register File Data Sampling (XSA-452)

User action
------------

Continue to update normally [1] in order to receive the security updates
described in the "Patching" section below. No other user action is
required in response to this QSB.

Summary
--------

On 2024-03-12, the Xen Project published XSA-452, "x86: Register File
Data Sampling" [3]:
| Intel have disclosed RFDS, Register File Data Sampling, affecting some
| Atom cores.
|
| This came from internal validation work. There is no information
| provided about how an attacker might go about inferring data from the
| register files.

For more details, see [4].

Impact
-------

An attacker might be able to infer the contents of data held previously
in floating point, vector, and/or integer register files on the same
core, including data from a more privileged context.

Affected systems
-----------------

At present, RFDS is known to affect only certain Atom cores from Intel.
Other Intel CPUs and CPUs from other hardware vendors are not known to
be affected.

RFDS affects Atom cores between the Goldmont and Gracemont
microarchitectures. This includes Alder Lake and Raptor Lake hybrid
client systems that have a mix of Gracemont and other types of cores.

Patching
---------

The following packages contain security updates that address the
vulnerabilities described in this bulletin:

For Qubes 4.1, in dom0:
- Xen packages version 4.14.6-7
- microcode_ctl 2.1-57.qubes1

For Qubes 4.2, in dom0:
- Xen packages version 4.17.3-4
- microcode_ctl 2.1-57.qubes1

These packages will migrate from the security-testing repository to the
current (stable) repository over the next two weeks after being tested
by the community. [2] Once available, the packages are to be installed
via the Qubes Update tool or its command-line equivalents. [1]

Dom0 must be restarted afterward in order for the updates to take
effect.

If you use Anti Evil Maid, you will need to reseal your secret
passphrase to new PCR values, as PCR18+19 will change due to the new
Xen binaries.

Credits
--------

See the original Xen Security Advisory.

References
-----------

[1] https://www.qubes-os.org/doc/how-to-update/
[2] https://www.qubes-os.org/doc/testing/
[3] https://xenbits.xen.org/xsa/advisory-452.html
[4] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/advisory-guidance/register-file-data-sampling.html

--
The Qubes Security Team
https://www.qubes-os.org/security/



Source: https://github.com/QubesOS/qubes-secpack/blob/main/QSBs/qsb-101-2024.txt

Marek Marczykowski-Górecki (https://www.qubes-os.org/team/#marek-marczykowski-g%C3%B3recki)’s PGP signature

-----BEGIN PGP SIGNATURE-----
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👍1
5B5yTEOCHpqqOCDAc+WopTiQFmJ9m5+dWYalSb2XcmPoIc21bHsYalWODFLr76Zv
Fj4Vxhb9Sp1DE3FfFpI78KG/4AZbv9nfwexy8Hpy6krRwzJxJSo=
=CgMr
-----END PGP SIGNATURE-----


Source: https://github.com/QubesOS/qubes-secpack/blob/main/QSBs/qsb-101-2024.txt.sig.marmarek

Simon Gaiser (aka HW42) (https://www.qubes-os.org/team/#simon-gaiser-aka-hw42)’s PGP signature

-----BEGIN PGP SIGNATURE-----

iQIzBAABCgAdFiEE6hjn8EDEHdrv6aoPSsGN4REuFJAFAmXxqpEACgkQSsGN4REu
FJAAmg/+JqRz8x1gF0bjKNSr38FWI2FgNg/DkmWw3cYtRiInobZejlvLy9vvX1ZL
yFYn/e4E0YIbhralqzmxYvE/dJ7DZdLQdJHODwJVk3QJT/DLrK65PmbAFxnof+wk
URWsouaQ0AAwAdWQCnTnlBHaKM8o/bdmcV9WbuSuKb64zJf2ciIU3iOQHPyxPj2Q
Whu8tg2JQZq6TVsVd6JcnD73ckQlkE58j8nyJP6WF4z5JfYvnCyzcgqbqDqabzbh
YhZyC5X8pNg5BVkX25xvun0NBj/P5NxeC1rcVTHK3XdYB8bBmoS6GobPC7T3jpCe
TQ8E2DbuAi5+oWZnMj8v0kdtNjezzP/9iWLsm865W6dczCMWZeh/nAs4aM6L1rG6
T7FogCV5lE9cVx3RqCPZpzAY9uaN0WryIZ/dLrmFbZR8T54UKWscmfWlak4TvBCS
1i3F2O4NgnzttaV/JW13hT9BUCMxc5uzYP/sRzw6zWGtxvQoSO+p3KmaFuscEhdt
tLNR5FAcmkbUUXg1uMOrrhfy5jEyLHretUzId3T9WPy9pnazcKnd6zT4HB6J+5bf
LNmriCIgQZ1B7yG7312Cadrrq3ktJPVEzUwYwx7I+7j/wQfQvaii0Lr+WM1DZUxH
KN+9pNV/SJ0I2gd5ObcX0gf8uchc548A5fIw21Oq1WopXtNEm48=
=XY1y
-----END PGP SIGNATURE-----


Source: https://github.com/QubesOS/qubes-secpack/blob/main/QSBs/qsb-101-2024.txt.sig.simon

What is the purpose of this announcement?

The purpose of this announcement is to inform the Qubes community that a new Qubes security bulletin (QSB) has been published.

What is a Qubes security bulletin (QSB)?

A Qubes security bulletin (QSB) is a security announcement issued by the Qubes security team (https://www.qubes-os.org/security/#qubes-security-team). A QSB typically provides a summary and impact analysis of one or more recently-discovered software vulnerabilities, including details about patching to address them. For a list of all QSBs, see Qubes security bulletins (QSBs) (https://www.qubes-os.org/security/qsb/).

Why should I care about QSBs?

QSBs tell you what actions you must take in order to protect yourself from recently-discovered security vulnerabilities. In most cases, security vulnerabilities are addressed by updating normally (https://www.qubes-os.org/doc/how-to-update/). However, in some cases, special user action is required. In all cases, the required actions are detailed in QSBs.

What are the PGP signatures that accompany QSBs?

A PGP (https://en.wikipedia.org/wiki/Pretty_Good_Privacy) signature is a cryptographic digital signature (https://en.wikipedia.org/wiki/Digital_signature) made in accordance with the OpenPGP (https://en.wikipedia.org/wiki/Pretty_Good_Privacy#OpenPGP) standard. PGP signatures can be cryptographically verified with programs like GNU Privacy Guard (GPG) (https://gnupg.org/). The Qubes security team cryptographically signs all QSBs so that Qubes users have a reliable way to check whether QSBs are genuine. The only way to be certain that a QSB is authentic is by verifying its PGP signatures.

Why should I care whether a QSB is authentic?

A forged QSB could deceive you into taking actions that adversely affect the security of your Qubes OS system, such as installing malware or making configuration changes that render your system vulnerable to attack. Falsified QSBs could sow fear, uncertainty, and doubt about the security of Qubes OS or the status of the Qubes OS Project.

How do I verify the PGP signatures on a QSB?

The following command-line instructions assume a Linux system with git and gpg installed. (For Windows and Mac options, see OpenPGP software (https://www.qubes-os.org/security/verifying-signatures/#openpgp-software).)



Obtain the Qubes Master Signing Key (QMSK), e.g.:

$ gpg --fetch-keys https://keys.qubes-os.org/keys/qubes-master-signing-key.asc
gpg: directory '/home/user/.gnupg' created
gpg: keybox '/home/user/.gnupg/pubring.kbx' created
gpg: requesting key from 'https://keys.qubes-os.org/keys/qubes-master-signing-key.asc'
gpg: /home/user/.gnupg/trustdb.gpg: trustdb created
gpg: key DDFA1A3E36879494: public key "Qubes Master Signing Key" imported
gpg: Total number processed: 1
gpg: imported: 1


(For more ways to obtain the QMSK, see How to import and authenticate the Qubes Master Signing Key (https://www.qubes-os.org/security/verifying-signatures/#how-to-import-and-authenticate-the-qubes-master-signing-key).)


View the fingerprint of the PGP key you just imported. (Note: gpg> indicates a prompt inside of the GnuPG program. Type what appears after it when prompted.)

$ gpg --edit-key 0x427F11FD0FAA4B080123F01CDDFA1A3E36879494
gpg (GnuPG) 2.2.27; Copyright (C) 2021 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.


pub rsa4096/DDFA1A3E36879494
created: 2010-04-01 expires: never usage: SC
trust: unknown validity: unknown
[ unknown] (1). Qubes Master Signing Key

gpg> fpr
pub rsa4096/DDFA1A3E36879494 2010-04-01 Qubes Master Signing Key
Primary key fingerprint: 427F 11FD 0FAA 4B08 0123 F01C DDFA 1A3E 3687 9494



Important: At this point, you still don’t know whether the key you just imported is the genuine QMSK or a forgery. In order for this entire procedure to provide meaningful security benefits, you must authenticate the QMSK out-of-band. Do not skip this step! The standard method is to obtain the QMSK fingerprint from multiple independent sources in several different ways and check to see whether they match the key you just imported. For more information, see How to import and authenticate the Qubes Master Signing Key (https://www.qubes-os.org/security/verifying-signatures/#how-to-import-and-authenticate-the-qubes-master-signing-key).

Tip: After you have authenticated the QMSK out-of-band to your satisfaction, record the QMSK fingerprint in a safe place (or several) so that you don’t have to repeat this step in the future.


Once you are satisfied that you have the genuine QMSK, set its trust level to 5 (“ultimate”), then quit GnuPG with q.

gpg> trust
pub rsa4096/DDFA1A3E36879494
created: 2010-04-01 expires: never usage: SC
trust: unknown validity: unknown
[ unknown] (1). Qubes Master Signing Key

Please decide how far you trust this user to correctly verify other users' keys
(by looking at passports, checking fingerprints from different sources, etc.)

1 = I don't know or won't say
2 = I do NOT trust
3 = I trust marginally
4 = I trust fully
5 = I trust ultimately
m = back to the main menu

Your decision? 5
Do you really want to set this key to ultimate trust? (y/N) y

pub rsa4096/DDFA1A3E36879494
created: 2010-04-01 expires: never usage: SC
trust: ultimate validity: unknown
[ unknown] (1). Qubes Master Signing Key
Please note that the shown key validity is not necessarily correct
unless you restart the program.

gpg> q



Use Git to clone the qubes-secpack repo.

$ git clone https://github.com/QubesOS/qubes-secpack.git
Cloning into 'qubes-secpack'...
remote: Enumerating objects: 4065, done.
remote: Counting objects: 100% (1474/1474), done.
remote: Compressing objects: 100% (742/742), done.
remote: Total 4065 (delta 743), reused 1413 (delta 731), pack-reused 2591
Receiving objects: 100% (4065/4065), 1.64 MiB | 2.53 MiB/s, done.
Resolving deltas: 100% (1910/1910), done.



Import the included PGP keys. (See our PGP key policies (https://www.qubes-os.org/security/pack/#pgp-key-policies) for important information about these keys.)

$ gpg --import qubes-secpack/keys/*/*
gpg: key 063938BA42CFA724: public key "Marek Marczykowski-Górecki (Qubes OS signing key)" imported
gpg: qubes-secpack/keys/core-devs/retired: read error: Is a directory
gpg: no valid OpenPGP data found.
gpg: key 8C05216CE09C093C: 1 signature not checked due to a missing key
gpg: key 8C05216CE09C093C: public key "HW42 (Qubes Signing Key)" imported
gpg: key DA0434BC706E1FCF: public key "Simon Gaiser (Qubes OS signing key)" imported
gpg: key 8CE137352A019A17: 2 signatures not checked due to missing keys
gpg: key 8CE137352A019A17: public key "Andrew David Wong (Qubes Documentation Signing Key)" imported
gpg: key AAA743B42FBC07A9: public key "Brennan Novak (Qubes Website & Documentation Signing)" imported
gpg: key B6A0BB95CA74A5C3: public key "Joanna Rutkowska (Qubes Documentation Signing Key)" imported
gpg: key F32894BE9684938A: public key "Marek Marczykowski-Górecki (Qubes Documentation Signing Key)" imported
gpg: key 6E7A27B909DAFB92: public key "Hakisho Nukama (Qubes Documentation Signing Key)" imported
gpg: key 485C7504F27D0A72: 1 signature not checked due to a missing key
gpg: key 485C7504F27D0A72: public key "Sven Semmler (Qubes Documentation Signing Key)" imported
gpg: key BB52274595B71262: public key "unman (Qubes Documentation Signing Key)" imported
gpg: key DC2F3678D272F2A8: 1 signature not checked due to a missing key
gpg: key DC2F3678D272F2A8: public key "Wojtek Porczyk (Qubes OS documentation signing key)" imported
gpg: key FD64F4F9E9720C4D: 1 signature not checked due to a missing key
gpg: key FD64F4F9E9720C4D: public key "Zrubi (Qubes Documentation Signing Key)" imported
gpg: key DDFA1A3E36879494: "Qubes Master Signing Key" not changed
gpg: key 1848792F9E2795E9: public key "Qubes OS Release 4 Signing Key" imported
gpg: qubes-secpack/keys/release-keys/retired: read error: Is a directory
gpg: no valid OpenPGP data found.
gpg: key D655A4F21830E06A: public key "Marek Marczykowski-Górecki (Qubes security pack)" imported
gpg: key ACC2602F3F48CB21: public key "Qubes OS Security Team" imported
gpg: qubes-secpack/keys/security-team/retired: read error: Is a directory
gpg: no valid OpenPGP data found.
gpg: key 4AC18DE1112E1490: public key "Simon Gaiser (Qubes Security Pack signing key)" imported
gpg: Total number processed: 17
gpg: imported: 16
gpg: unchanged: 1
gpg: marginals needed: 3 completes needed: 1 trust model: pgp
gpg: depth: 0 valid: 1 signed: 6 trust: 0-, 0q, 0n, 0m, 0f, 1u
gpg: depth: 1 valid: 6 signed: 0 trust: 6-, 0q, 0n, 0m, 0f, 0u



Verify signed Git tags.

$ cd qubes-secpack/
$ git tag -v `git describe`
object 266e14a6fae57c9a91362c9ac784d3a891f4d351
type commit
tag marmarek_sec_266e14a6
tagger Marek Marczykowski-Górecki 1677757924 +0100

Tag for commit 266e14a6fae57c9a91362c9ac784d3a891f4d351
gpg: Signature made Thu 02 Mar 2023 03:52:04 AM PST
gpg: using RSA key 2D1771FE4D767EDC76B089FAD655A4F21830E06A
gpg: Good signature from "Marek Marczykowski-Górecki (Qubes security pack)" [full]


The exact output will differ, but the final line should always start with gpg: Good signature from... followed by an appropriate key. The [full] indicates full trust, which this key inherits in virtue of being validly signed by the QMSK.


Verify PGP signatures, e.g.:

$ cd QSBs/
$ gpg --verify qsb-087-2022.txt.sig.marmarek qsb-087-2022.txt
gpg: Signature made Wed 23 Nov 2022 04:05:51 AM PST
gpg: using RSA key 2D1771FE4D767EDC76B089FAD655A4F21830E06A
gpg: Good signature from "Marek Marczykowski-Górecki (Qubes security pack)" [full]
$ gpg --verify qsb-087-2022.txt.sig.simon qsb-087-2022.txt
gpg: Signature made Wed 23 Nov 2022 03:50:42 AM PST
gpg: using RSA key EA18E7F040C41DDAEFE9AA0F4AC18DE1112E1490
gpg: Good signature from "Simon Gaiser (Qubes Security Pack signing key)" [full]
$ cd ../canaries/
$ gpg --verify canary-034-2023.txt.sig.marmarek canary-034-2023.txt
gpg: Signature made Thu 02 Mar 2023 03:51:48 AM PST
gpg: using RSA key 2D1771FE4D767EDC76B089FAD655A4F21830E06A
gpg: Good signature from "Marek Marczykowski-Górecki (Qubes security pack)" [full]
$ gpg --verify canary-034-2023.txt.sig.simon canary-034-2023.txt
gpg: Signature made Thu 02 Mar 2023 01:47:52 AM PST
gpg: using RSA key EA18E7F040C41DDAEFE9AA0F4AC18DE1112E1490
gpg: Good signature from "Simon Gaiser (Qubes Security Pack signing key)" [full]


Again, the exact output will differ, but the final line of output from each gpg --verify command should always start with gpg: Good signature from... followed by an appropriate key.



For this announcement (QSB-101), the commands are:

$ gpg --verify qsb-101-2024.txt.sig.marmarek qsb-101-2024.txt
$ gpg --verify qsb-101-2024.txt.sig.simon qsb-101-2024.txt


You can also verify the signatures directly from this announcement in addition to or instead of verifying the files from the qubes-secpack. Simply copy and paste the QSB-101 text into a plain text file and do the same for both signature files. Then, perform the same authentication steps as listed above, substituting the filenames above with the names of the files you just created.
Qubes OS 4.2.1-rc1 is available for testing
https://www.qubes-os.org/news/2024/03/16/qubes-os-4-2-1-rc1-available-for-testing/

We’re pleased to announce that the first release candidate (RC) (https://www.qubes-os.org/news/2024/03/16/qubes-os-4-2-1-rc1-available-for-testing/#what-is-a-release-candidate) for Qubes OS 4.2.1 is now available for testing (https://www.qubes-os.org/doc/testing/). This patch release (https://www.qubes-os.org/news/2024/03/16/qubes-os-4-2-1-rc1-available-for-testing/#what-is-a-patch-release) aims to consolidate all the security patches, bug fixes, and other updates that have occurred since the release of Qubes 4.2.0. Our goal is to provide a secure and convenient way for users to install (or reinstall) the latest stable Qubes release with an up-to-date ISO. The ISO and associated verification files (https://www.qubes-os.org/security/verifying-signatures/) are available on the downloads (https://www.qubes-os.org/downloads/) page. For more information about the changes included in this version, see the full list of issues completed since the release of 4.2.0 (https://github.com/QubesOS/qubes-issues/issues?q=is%3Aissue+is%3Aclosed+reason%3Acompleted+closed%3A2023-12-18..2024-03-14+-label%3A%22R%3A+cannot+reproduce%22+-label%3A%22R%3A+declined%22+-label%3A%22R%3A+duplicate%22+-label%3A%22R%3A+not+applicable%22+-label%3A%22R%3A+self-closed%22+-label%3A%22R%3A+upstream+issue%22+).

When is the stable release?

That depends on the number of bugs discovered in this RC and their severity. As explained in our release schedule (https://www.qubes-os.org/doc/version-scheme/#release-schedule) documentation, our usual process after issuing a new RC is to collect bug reports, triage the bugs, and fix them. If warranted, we then issue a new RC that includes the fixes and repeat the process. We continue this iterative procedure until we’re left with an RC that’s good enough to be declared the stable release. No one can predict, at the outset, how many iterations will be required (and hence how many RCs will be needed before a stable release), but we tend to get a clearer picture of this as testing progresses. Here is the latest update:

At this point, we expect the stable release sometime around 2024-03-25.

Testing Qubes 4.2.1-rc1

If you’re willing to test (https://www.qubes-os.org/doc/testing/) this new RC, you can help us improve the eventual stable release by reporting any bugs you encounter (https://www.qubes-os.org/doc/issue-tracking/). We encourage experienced users to join the testing team (https://forum.qubes-os.org/t/joining-the-testing-team/5190). The best way to test Qubes 4.2.1-rc1 is by performing a clean installation (https://www.qubes-os.org/doc/installation-guide/) with the new ISO. We strongly recommend making a full backup (https://www.qubes-os.org/doc/how-to-back-up-restore-and-migrate/) beforehand.

As an alternative to a clean installation, there is also the option of performing an in-place upgrade without reinstalling. However, since Qubes 4.2.1 is simply Qubes 4.2.0 inclusive of all updates to date, this amounts to simply using a fully-updated 4.2.0 installation. In a sense, then, all current 4.2.0 users who are keeping up with updates are already testing 4.2.1-rc1, but this testing is only partial, since it does not cover things like the installation procedure.

Reminder: new signing key for Qubes OS 4.2

As a reminder, we published the following special announcement in Qubes Canary 032 (https://www.qubes-os.org/news/2022/09/14/canary-032/) on 2022-09-14:


We plan to create a new Release Signing Key (RSK) for Qubes OS 4.2. Normally, we have only one RSK for each major release. However, for the 4.2 release, we will be using Qubes Builder version 2, which is a complete rewrite of the Qubes Builder. Out of an abundance of caution, we would like to isolate the build processes of the current stable 4.1 release and the upcoming 4.2 release from each other at the cryptographic level in order to
minimize the risk of a vulnerability in one affecting the other. We are including this notice as a canary special announcement since introducing a new RSK for a minor release is an exception to our usual RSK management policy.


As always, we encourage you to authenticate (https://www.qubes-os.org/security/pack/#how-to-obtain-and-authenticate) this canary by verifying its PGP signatures (https://www.qubes-os.org/security/verifying-signatures/). Specific instructions are also included in the canary announcement (https://www.qubes-os.org/news/2022/09/14/canary-032/).

As with all Qubes signing keys, we also encourage you to authenticate (https://www.qubes-os.org/security/verifying-signatures/#how-to-import-and-authenticate-release-signing-keys) the new Qubes OS Release 4.2 Signing Key, which is available in the Qubes Security Pack (qubes-secpack) (https://www.qubes-os.org/security/pack/) as well as on the downloads (https://www.qubes-os.org/downloads/) page.

What is a release candidate?

A release candidate (RC) is a software build that has the potential to become a stable release, unless significant bugs are discovered in testing. RCs are intended for more advanced (or adventurous!) users who are comfortable testing early versions of software that are potentially buggier than stable releases. You can read more about Qubes OS supported releases (https://www.qubes-os.org/doc/supported-releases/) and the version scheme (https://www.qubes-os.org/doc/version-scheme/) in our documentation.

What is a patch release?

The Qubes OS Project uses the semantic versioning (https://semver.org/) standard. Version numbers are written as ... Hence, we refer to releases that increment the third number as “patch releases.” A patch release does not designate a separate, new major or minor release of Qubes OS. Rather, it designates its respective major or minor release (in this case, 4.2) inclusive of all updates up to a certain point. (See supported releases (https://www.qubes-os.org/doc/supported-releases/) for a comprehensive list of major and minor releases.) Installing the initial Qubes 4.2.0 release and fully updating (https://www.qubes-os.org/doc/how-to-update/) it results in essentially the same system as installing Qubes 4.2.1. You can learn more about how Qubes release versioning works in the version scheme (https://www.qubes-os.org/doc/version-scheme/) documentation.
Update for QSB-101: Register File Data Sampling (XSA-452) and Intel Processor Return Predictions Advisory (INTEL-SA-00982)
https://www.qubes-os.org/news/2024/03/18/qsb-101-update/

We have updated Qubes Security Bulletin (QSB) 101: Register File Data Sampling (XSA-452) and Intel Processor Return Predictions Advisory (INTEL-SA-00982) (https://github.com/QubesOS/qubes-secpack/blob/c5693c8a4b81b3afb7cd7e6e44db3bbc36987049/QSBs/qsb-101-2024.txt). The text of this updated QSB (including a changelog) and its accompanying cryptographic signature are reproduced below, followed by a general explanation of this announcement and authentication instructions.

Qubes Security Bulletin 101


---===[ Qubes Security Bulletin 101 ]===---

2024-03-12

Register File Data Sampling (XSA-452) and
Intel Processor Return Predictions Advisory (INTEL-SA-00982)

Changelog
----------

2024-03-12: Original QSB
2024-03-17: Add information about INTEL-SA-00982

User action
------------

Continue to update normally [1] in order to receive the security updates
described in the "Patching" section below. No other user action is
required in response to this QSB.

Summary
--------

On 2024-03-12, the Xen Project published XSA-452, "x86: Register File
Data Sampling" [3]:

| Intel have disclosed RFDS, Register File Data Sampling, affecting some
| Atom cores.
|
| This came from internal validation work. There is no information
| provided about how an attacker might go about inferring data from the
| register files.

For more information, see Intel's security advisory. [4]

In addition, Intel published INTEL-SA-00982/CVE-2023-38575 [6] on the
same day:

| Non-transparent sharing of return predictor targets between contexts
| in some Intel® Processors may allow an authorized user to potentially
| enable information disclosure via local access.

Information about this vulnerability is very sparse.

Impact
-------

On systems affected by Register File Data Sampling (RFDS), an attacker
might be able to infer the contents of data previously held in floating
point, vector, and/or integer register files on the same core, including
data from a more privileged context.

On systems affected by INTEL-SA-00982, an attacker might be able to leak
information from other security contexts, but the precise impact is
unclear.

Affected systems
-----------------

At present, Register File Data Sampling (RFDS) is known to affect only
certain Atom cores from Intel. Other Intel CPUs and CPUs from other
hardware vendors are not known to be affected. RFDS affects Atom cores
between the Goldmont and Gracemont microarchitectures. This includes
Alder Lake and Raptor Lake hybrid client systems that have a mix of
Gracemont and other types of cores.

At the time of this writing, Intel has not published information about
which systems INTEL-SA-00982 affects. Systems that are still receiving
microcode updates from Intel [7] and that received a microcode update as
part of the microcode release on 2024-03-12 [5] may be affected, even if
they are not affected by RFDS.

Patching
---------

The following packages contain security updates that address the
vulnerabilities described in this bulletin:

For Qubes 4.1, in dom0:
- Xen packages version 4.14.6-7
- microcode_ctl 2.1-57.qubes1

For Qubes 4.2, in dom0:
- Xen packages version 4.17.3-4
- microcode_ctl 2.1-57.qubes1

These packages will migrate from the security-testing repository to the
current (stable) repository over the next two weeks after being tested
by the community. [2] Once available, the packages are to be installed
via the Qubes Update tool or its command-line equivalents. [1]

Dom0 must be restarted afterward in order for the updates to take
effect.

If you use Anti Evil Maid, you will need to reseal your secret
passphrase to new PCR values, as PCR18+19 will change due to the new
Xen binaries.

Credits
--------

See the original Xen Security Advisory.

References
[5] https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/blob/main/releasenote.md#microcode-20240312
[6] https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00982.html
[7] https://www.intel.com/content/www/us/en/support/articles/000022396/processors.html

--
The Qubes Security Team
https://www.qubes-os.org/security/



Source: https://github.com/QubesOS/qubes-secpack/blob/c5693c8a4b81b3afb7cd7e6e44db3bbc36987049/QSBs/qsb-101-2024.txt

Marek Marczykowski-Górecki (https://www.qubes-os.org/team/#marek-marczykowski-g%C3%B3recki)’s PGP signature

At the time of this writing, Marek is traveling and is therefore not available to sign this QSB update. He will sign it when he returns. In the meantime, you can still authenticate his original signature (https://github.com/QubesOS/qubes-secpack/blob/ea3a31c4295b91e3f77ee39a15bcabbbd956678b/QSBs/qsb-101-2024.txt.sig.marmarek) on the original version (https://github.com/QubesOS/qubes-secpack/blob/ea3a31c4295b91e3f77ee39a15bcabbbd956678b/QSBs/qsb-101-2024.txt) of this QSB. For more information, see the original QSB-101 announcement (https://www.qubes-os.org/news/2024/03/13/qsb-101/).

Simon Gaiser (aka HW42) (https://www.qubes-os.org/team/#simon-gaiser-aka-hw42)’s PGP signature

-----BEGIN PGP SIGNATURE-----

iQIzBAABCgAdFiEE6hjn8EDEHdrv6aoPSsGN4REuFJAFAmX3fZEACgkQSsGN4REu
FJAHCg/5AYLGAcnMRzZ1JgSJXQLLuQqIXfpNfZWHT4e9u6gkDYcrI4Z4AEzab5Lv
YqSeNbtMys1WCxCUXyPUNG+ZNrD9xcCfmaZuC+MNINwRoAcg+V5+B8cCMU9NUB+V
IquFrepWJcimsBeAvCPkCV4nk1BABqEu0vsViifwFvS0MWr7VFUkQom5/XkXwmZY
uUTrNWSKoJzmzwq3x0yWVNhLmjD2nMg2BKeJUiwpy1wE9Q0w9dLrHEwwewuHP7t1
JAiOFLvEAw55D9Cw8YbOWskIfHWeyhA4a8nrbPVMRTBJAryUgRtDQx6GCcn5uLiM
+/vnYu26UigX9eQy2T/O5fs3ti4BF+/D7XO9QnKXVsmAtSTfvP7/nzY8nWL9SzpB
7cBX5AH9QTHa2Rji/EpqSsZawXXs5pMTWbzObkBORObNgkHUMPOhaM+8qZaEhm5h
DMZrsCHbOsi38pmrXhuIhzY/j5Sk+wp3Wgvkqq4CXO8n7H+jjPNTrMEfcgYI/C8U
U17OvqA/iC/C/z1BRQnhiAp98/fYN6jgNWAGVMBM+XgbrCHExnP/OCH6X5pgTYwY
JbwMyFxv9XuQMDFc9zF4AVPHdAAGssU9qZDZlJg/72Az7J4kxHNlT3m9u02ljmgC
POHJyjO071i6xlCMMEuYyrgT/1qs5NjocpWaXfYSl45a3DWeHMo=
=ZGQ8
-----END PGP SIGNATURE-----


Source: https://github.com/QubesOS/qubes-secpack/blob/c5693c8a4b81b3afb7cd7e6e44db3bbc36987049/QSBs/qsb-101-2024.txt.sig.simon

What is the purpose of this announcement?

The purpose of this announcement is to inform the Qubes community that a new Qubes security bulletin (QSB) has been published.

What is a Qubes security bulletin (QSB)?

A Qubes security bulletin (QSB) is a security announcement issued by the Qubes security team (https://www.qubes-os.org/security/#qubes-security-team). A QSB typically provides a summary and impact analysis of one or more recently-discovered software vulnerabilities, including details about patching to address them. For a list of all QSBs, see Qubes security bulletins (QSBs) (https://www.qubes-os.org/security/qsb/).

Why should I care about QSBs?

QSBs tell you what actions you must take in order to protect yourself from recently-discovered security vulnerabilities. In most cases, security vulnerabilities are addressed by updating normally (https://www.qubes-os.org/doc/how-to-update/). However, in some cases, special user action is required. In all cases, the required actions are detailed in QSBs.

What are the PGP signatures that accompany QSBs?

A PGP (https://en.wikipedia.org/wiki/Pretty_Good_Privacy) signature is a cryptographic digital signature (https://en.wikipedia.org/wiki/Digital_signature) made in accordance with the OpenPGP (https://en.wikipedia.org/wiki/Pretty_Good_Privacy#OpenPGP) standard. PGP signatures can be cryptographically verified with programs like GNU Privacy Guard (GPG) (https://gnupg.org/). The Qubes security team cryptographically signs all QSBs so that Qubes users have a reliable way to check whether QSBs are genuine. The only way to be certain that a QSB is authentic is by verifying its PGP signatures.

Why should I care whether a QSB is authentic?
A forged QSB could deceive you into taking actions that adversely affect the security of your Qubes OS system, such as installing malware or making configuration changes that render your system vulnerable to attack. Falsified QSBs could sow fear, uncertainty, and doubt about the security of Qubes OS or the status of the Qubes OS Project.

How do I verify the PGP signatures on a QSB?

The following command-line instructions assume a Linux system with git and gpg installed. (For Windows and Mac options, see OpenPGP software (https://www.qubes-os.org/security/verifying-signatures/#openpgp-software).)



Obtain the Qubes Master Signing Key (QMSK), e.g.:

$ gpg --fetch-keys https://keys.qubes-os.org/keys/qubes-master-signing-key.asc
gpg: directory '/home/user/.gnupg' created
gpg: keybox '/home/user/.gnupg/pubring.kbx' created
gpg: requesting key from 'https://keys.qubes-os.org/keys/qubes-master-signing-key.asc'
gpg: /home/user/.gnupg/trustdb.gpg: trustdb created
gpg: key DDFA1A3E36879494: public key "Qubes Master Signing Key" imported
gpg: Total number processed: 1
gpg: imported: 1


(For more ways to obtain the QMSK, see How to import and authenticate the Qubes Master Signing Key (https://www.qubes-os.org/security/verifying-signatures/#how-to-import-and-authenticate-the-qubes-master-signing-key).)


View the fingerprint of the PGP key you just imported. (Note: gpg> indicates a prompt inside of the GnuPG program. Type what appears after it when prompted.)

$ gpg --edit-key 0x427F11FD0FAA4B080123F01CDDFA1A3E36879494
gpg (GnuPG) 2.2.27; Copyright (C) 2021 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.


pub rsa4096/DDFA1A3E36879494
created: 2010-04-01 expires: never usage: SC
trust: unknown validity: unknown
[ unknown] (1). Qubes Master Signing Key

gpg> fpr
pub rsa4096/DDFA1A3E36879494 2010-04-01 Qubes Master Signing Key
Primary key fingerprint: 427F 11FD 0FAA 4B08 0123 F01C DDFA 1A3E 3687 9494



Important: At this point, you still don’t know whether the key you just imported is the genuine QMSK or a forgery. In order for this entire procedure to provide meaningful security benefits, you must authenticate the QMSK out-of-band. Do not skip this step! The standard method is to obtain the QMSK fingerprint from multiple independent sources in several different ways and check to see whether they match the key you just imported. For more information, see How to import and authenticate the Qubes Master Signing Key (https://www.qubes-os.org/security/verifying-signatures/#how-to-import-and-authenticate-the-qubes-master-signing-key).

Tip: After you have authenticated the QMSK out-of-band to your satisfaction, record the QMSK fingerprint in a safe place (or several) so that you don’t have to repeat this step in the future.


Once you are satisfied that you have the genuine QMSK, set its trust level to 5 (“ultimate”), then quit GnuPG with q.

gpg> trust
pub rsa4096/DDFA1A3E36879494
created: 2010-04-01 expires: never usage: SC
trust: unknown validity: unknown
[ unknown] (1). Qubes Master Signing Key

Please decide how far you trust this user to correctly verify other users' keys
(by looking at passports, checking fingerprints from different sources, etc.)

1 = I don't know or won't say
2 = I do NOT trust
3 = I trust marginally
4 = I trust fully
5 = I trust ultimately
m = back to the main menu

Your decision? 5
Do you really want to set this key to ultimate trust? (y/N) y

pub rsa4096/DDFA1A3E36879494
created: 2010-04-01 expires: never usage: SC
trust: ultimate validity: unknown
[ unknown] (1). Qubes Master Signing Key
Please note that the shown key validity is not necessarily correct
unless you restart the program.

gpg> q
Use Git to clone the qubes-secpack repo.

$ git clone https://github.com/QubesOS/qubes-secpack.git
Cloning into 'qubes-secpack'...
remote: Enumerating objects: 4065, done.
remote: Counting objects: 100% (1474/1474), done.
remote: Compressing objects: 100% (742/742), done.
remote: Total 4065 (delta 743), reused 1413 (delta 731), pack-reused 2591
Receiving objects: 100% (4065/4065), 1.64 MiB | 2.53 MiB/s, done.
Resolving deltas: 100% (1910/1910), done.



Import the included PGP keys. (See our PGP key policies (https://www.qubes-os.org/security/pack/#pgp-key-policies) for important information about these keys.)

$ gpg --import qubes-secpack/keys/*/*
gpg: key 063938BA42CFA724: public key "Marek Marczykowski-Górecki (Qubes OS signing key)" imported
gpg: qubes-secpack/keys/core-devs/retired: read error: Is a directory
gpg: no valid OpenPGP data found.
gpg: key 8C05216CE09C093C: 1 signature not checked due to a missing key
gpg: key 8C05216CE09C093C: public key "HW42 (Qubes Signing Key)" imported
gpg: key DA0434BC706E1FCF: public key "Simon Gaiser (Qubes OS signing key)" imported
gpg: key 8CE137352A019A17: 2 signatures not checked due to missing keys
gpg: key 8CE137352A019A17: public key "Andrew David Wong (Qubes Documentation Signing Key)" imported
gpg: key AAA743B42FBC07A9: public key "Brennan Novak (Qubes Website & Documentation Signing)" imported
gpg: key B6A0BB95CA74A5C3: public key "Joanna Rutkowska (Qubes Documentation Signing Key)" imported
gpg: key F32894BE9684938A: public key "Marek Marczykowski-Górecki (Qubes Documentation Signing Key)" imported
gpg: key 6E7A27B909DAFB92: public key "Hakisho Nukama (Qubes Documentation Signing Key)" imported
gpg: key 485C7504F27D0A72: 1 signature not checked due to a missing key
gpg: key 485C7504F27D0A72: public key "Sven Semmler (Qubes Documentation Signing Key)" imported
gpg: key BB52274595B71262: public key "unman (Qubes Documentation Signing Key)" imported
gpg: key DC2F3678D272F2A8: 1 signature not checked due to a missing key
gpg: key DC2F3678D272F2A8: public key "Wojtek Porczyk (Qubes OS documentation signing key)" imported
gpg: key FD64F4F9E9720C4D: 1 signature not checked due to a missing key
gpg: key FD64F4F9E9720C4D: public key "Zrubi (Qubes Documentation Signing Key)" imported
gpg: key DDFA1A3E36879494: "Qubes Master Signing Key" not changed
gpg: key 1848792F9E2795E9: public key "Qubes OS Release 4 Signing Key" imported
gpg: qubes-secpack/keys/release-keys/retired: read error: Is a directory
gpg: no valid OpenPGP data found.
gpg: key D655A4F21830E06A: public key "Marek Marczykowski-Górecki (Qubes security pack)" imported
gpg: key ACC2602F3F48CB21: public key "Qubes OS Security Team" imported
gpg: qubes-secpack/keys/security-team/retired: read error: Is a directory
gpg: no valid OpenPGP data found.
gpg: key 4AC18DE1112E1490: public key "Simon Gaiser (Qubes Security Pack signing key)" imported
gpg: Total number processed: 17
gpg: imported: 16
gpg: unchanged: 1
gpg: marginals needed: 3 completes needed: 1 trust model: pgp
gpg: depth: 0 valid: 1 signed: 6 trust: 0-, 0q, 0n, 0m, 0f, 1u
gpg: depth: 1 valid: 6 signed: 0 trust: 6-, 0q, 0n, 0m, 0f, 0u



Verify signed Git tags.

$ cd qubes-secpack/
$ git tag -v `git describe`
object 266e14a6fae57c9a91362c9ac784d3a891f4d351
type commit
tag marmarek_sec_266e14a6
tagger Marek Marczykowski-Górecki 1677757924 +0100

Tag for commit 266e14a6fae57c9a91362c9ac784d3a891f4d351
gpg: Signature made Thu 02 Mar 2023 03:52:04 AM PST
gpg: using RSA key 2D1771FE4D767EDC76B089FAD655A4F21830E06A
gpg: Good signature from "Marek Marczykowski-Górecki (Qubes security pack)" [full]


The exact output will differ, but the final line should always start with gpg: Good signature from... followed by an appropriate key. The [full] indicates full trust, which this key inherits in virtue of being validly signed by the QMSK.
Verify PGP signatures, e.g.:

$ cd QSBs/
$ gpg --verify qsb-087-2022.txt.sig.marmarek qsb-087-2022.txt
gpg: Signature made Wed 23 Nov 2022 04:05:51 AM PST
gpg: using RSA key 2D1771FE4D767EDC76B089FAD655A4F21830E06A
gpg: Good signature from "Marek Marczykowski-Górecki (Qubes security pack)" [full]
$ gpg --verify qsb-087-2022.txt.sig.simon qsb-087-2022.txt
gpg: Signature made Wed 23 Nov 2022 03:50:42 AM PST
gpg: using RSA key EA18E7F040C41DDAEFE9AA0F4AC18DE1112E1490
gpg: Good signature from "Simon Gaiser (Qubes Security Pack signing key)" [full]
$ cd ../canaries/
$ gpg --verify canary-034-2023.txt.sig.marmarek canary-034-2023.txt
gpg: Signature made Thu 02 Mar 2023 03:51:48 AM PST
gpg: using RSA key 2D1771FE4D767EDC76B089FAD655A4F21830E06A
gpg: Good signature from "Marek Marczykowski-Górecki (Qubes security pack)" [full]
$ gpg --verify canary-034-2023.txt.sig.simon canary-034-2023.txt
gpg: Signature made Thu 02 Mar 2023 01:47:52 AM PST
gpg: using RSA key EA18E7F040C41DDAEFE9AA0F4AC18DE1112E1490
gpg: Good signature from "Simon Gaiser (Qubes Security Pack signing key)" [full]


Again, the exact output will differ, but the final line of output from each gpg --verify command should always start with gpg: Good signature from... followed by an appropriate key.



For this announcement (QSB-101), the command is:

$ gpg --verify qsb-101-2024.txt.sig.simon qsb-101-2024.txt


You can also verify the signature directly from this announcement in addition to or instead of verifying the files from the qubes-secpack. Simply copy and paste the QSB-101 text into a plain text file and do the same for the signature file. Then, perform the same authentication steps as listed above, substituting the filenames above with the names of the files you just created.
Qubes OS pinned «Qubes OS 4.2.1-rc1 is available for testing https://www.qubes-os.org/news/2024/03/16/qubes-os-4-2-1-rc1-available-for-testing/ We’re pleased to announce that the first release candidate (RC) (https://www.qubes-os.org/news/2024/03/16/qubes-os-4-2-1-rc1-available…»
Qubes OS 4.2.1 has been released!
https://www.qubes-os.org/news/2024/03/26/qubes-os-4-2-1-has-been-released/

We’re pleased to announce the stable release of Qubes OS 4.2.1! This patch release (https://www.qubes-os.org/news/2024/03/26/qubes-os-4-2-1-has-been-released/#what-is-a-patch-release) aims to consolidate all the security patches, bug fixes, and other updates that have occurred since the release of Qubes 4.2.0. Our goal is to provide a secure and convenient way for users to install (or reinstall) the latest stable Qubes release with an up-to-date ISO. The ISO and associated verification files (https://www.qubes-os.org/security/verifying-signatures/) are available on the downloads (https://www.qubes-os.org/downloads/) page.

What’s new in Qubes OS 4.2.1?

Qubes 4.2.1 includes numerous updates over the initial 4.2.0 release, in particular:


All 4.2 dom0 updates to date
Fedora 39 template
Linux 6.6.x as the default kernel, significantly reducing the need for kernel-latest on newer systems


For more information about the changes included in this version, see the full list of issues completed since the release of 4.2.0 (https://github.com/QubesOS/qubes-issues/issues?q=is%3Aissue+is%3Aclosed+reason%3Acompleted+closed%3A2023-12-18..2024-03-14+-label%3A%22R%3A+cannot+reproduce%22+-label%3A%22R%3A+declined%22+-label%3A%22R%3A+duplicate%22+-label%3A%22R%3A+not+applicable%22+-label%3A%22R%3A+self-closed%22+-label%3A%22R%3A+upstream+issue%22+).

How to get Qubes OS 4.2.1

You have a few different options, depending on your situation:



If you’d like to install Qubes OS for the first time or perform a clean reinstallation on an existing system, there’s never been a better time to do so! Simply download (https://www.qubes-os.org/downloads/) the Qubes 4.2.1 ISO and follow our installation guide (https://www.qubes-os.org/doc/installation-guide/).


If you’re currently on Qubes 4.1, learn how to upgrade to Qubes 4.2 (https://www.qubes-os.org/doc/upgrade/4.2/).


If you’re currently on Qubes 4.2 (including 4.2.0 and 4.2.1-rc1), update normally (https://www.qubes-os.org/doc/how-to-update/) (which includes upgrading any EOL templates (https://www.qubes-os.org/doc/how-to-update/#upgrading-to-avoid-eol) you might have) in order to make your system essentially equivalent to the stable Qubes 4.2.1 release. No reinstallation or other special action is required.



In all cases, we strongly recommend making a full backup (https://www.qubes-os.org/doc/how-to-back-up-restore-and-migrate/) beforehand.

Reminder: new signing key for Qubes OS 4.2

As a reminder, we published the following special announcement in Qubes Canary 032 (https://www.qubes-os.org/news/2022/09/14/canary-032/) on 2022-09-14:


We plan to create a new Release Signing Key (RSK) for Qubes OS 4.2. Normally, we have only one RSK for each major release. However, for the 4.2 release, we will be using Qubes Builder version 2, which is a complete rewrite of the Qubes Builder. Out of an abundance of caution, we would like to isolate the build processes of the current stable 4.1 release and the upcoming 4.2 release from each other at the cryptographic level in order to minimize the risk of a vulnerability in one affecting the other. We are including this notice as a canary special announcement since introducing a new RSK for a minor release is an exception to our usual RSK management policy.


As always, we encourage you to authenticate (https://www.qubes-os.org/security/pack/#how-to-obtain-and-authenticate) this canary by verifying its PGP signatures (https://www.qubes-os.org/security/verifying-signatures/). Specific instructions are also included in the canary announcement (https://www.qubes-os.org/news/2022/09/14/canary-032/).
As with all Qubes signing keys, we also encourage you to authenticate (https://www.qubes-os.org/security/verifying-signatures/#how-to-import-and-authenticate-release-signing-keys) the new Qubes OS Release 4.2 Signing Key, which is available in the Qubes Security Pack (qubes-secpack) (https://www.qubes-os.org/security/pack/) as well as on the downloads (https://www.qubes-os.org/downloads/) page.

What is a patch release?

The Qubes OS Project uses the semantic versioning (https://semver.org/) standard. Version numbers are written as ... Hence, we refer to releases that increment the third number as “patch releases.” A patch release does not designate a separate, new major or minor release of Qubes OS. Rather, it designates its respective major or minor release (in this case, 4.2) inclusive of all updates up to a certain point. (See supported releases (https://www.qubes-os.org/doc/supported-releases/) for a comprehensive list of major and minor releases.) Installing the initial Qubes 4.2.0 release and fully updating (https://www.qubes-os.org/doc/how-to-update/) it results in essentially the same system as installing Qubes 4.2.1. You can learn more about how Qubes release versioning works in the version scheme (https://www.qubes-os.org/doc/version-scheme/) documentation.