Search Results: "tora"

7 January 2024

Jonathan McDowell: Free Software Activities for 2023

This year was hard from a personal and work point of view, which impacted the amount of Free Software bits I ended up doing - even when I had the time I often wasn t in the right head space to make progress on things. However writing this annual recap up has been a useful exercise, as I achieved more than I realised. For previous years see 2019, 2020, 2021 + 2022.

Conferences The only Free Software related conference I made it to this year was DebConf23 in Kochi, India. Changes with projects at work meant I couldn t justify anything work related. This year I m planning to make it to FOSDEM, and haven t made a decision on DebConf24 yet.

Debian Most of my contributions to Free software continue to happen within Debian. I started the year working on retrogaming with Kodi on Debian. I got this to a much better state for bookworm, with it being possible to run the bsnes-mercury emulator under Kodi using RetroArch. There are a few other libretro backends available for RetroArch, but Kodi needs some extra controller mappings packaged up first. Plenty of uploads were involved, though some of this was aligning all the dependencies and generally cleaning things up in iterations. I continued to work on a few packages within the Debian Electronics Packaging Team. OpenOCD produced a new release in time for the bookworm release, so I uploaded 0.12.0-1. There were a few minor sigrok cleanups - sigrok 0.3, libsigrokdecode 0.5.3-4 + libsigrok 0.5.2-4 / 0.5.2-5. While I didn t manage to get the work completed I did some renaming of the ESP8266 related packages - gcc-xtensa-lx106 (which saw a 13 upload pre-bookworm) has become gcc-xtensa (with 14) and binutils-xtensa-lx106 has become binutils-xtensa (with 6). Binary packages remain the same, but this is intended to allow for the generation of ESP32 compiler toolchains from the same source. onak saw 0.6.3-1 uploaded to match the upstream release. I also uploaded libgpg-error 1.47-1 (though I can claim no credit for any of the work in preparing the package) to help move things forward on updating gnupg2 in Debian. I NMUed tpm2-pkcs11 1.9.0-0.1 to fix some minor issues pre-bookworm release; I use this package myself to store my SSH key within my laptop TPM, so I care about it being in a decent state. sg3-utils also saw a bit of love with 1.46-2 + 1.46-3 - I don t work in the storage space these days, but I m still listed as an uploaded and there was an RC bug around the library package naming that I was qualified to fix and test pre-bookworm. Related to my retroarch work I sponsored uploads of mgba for Ryan Tandy: 0.10.0+dfsg-1, 0.10.0+dfsg-2, 0.10.1+dfsg-1, 0.10.2+dfsg-1, mgba 0.10.1+dfsg-1+deb12u1. As part of the Data Protection Team I responded to various inbound queries to that team, both from project members and those external to the project. I continue to keep an eye on Debian New Members, even though I m mostly inactive as an application manager - we generally seem to have enough available recently. Mostly my involvement is via Front Desk activities, helping out with queries to the team alias, and contributing to internal discussions as well as our panel at DebConf23. Finally the 3 month rotation for Debian Keyring continues to operate smoothly. I dealt with 2023.03.24, 2023.06.26, 2023.06.29, 2023.09.10, 2023.09.24 + 2023.12.24.

Linux I had a few minor patches accepted to the kernel this year. A pair of safexcel cleanups (improved error logging for firmware load fail and cleanup on load failure) came out of upgrading the kernel running on my RB5009. The rest were related to my work on repurposing my C.H.I.P.. The AXP209 driver needed extended to support GPIO3 (with associated DT schema update). That allowed Bluetooth to be enabled. Adding the AXP209 internal temperature ADC as an iio-hwmon node means it can be tracked using the normal sensor monitoring framework. And finally I added the pinmux settings for mmc2, which I use to support an external microSD slot on my C.H.I.P.

Personal projects 2023 saw another minor release of onak, 0.6.3, which resulted in a corresponding Debian upload (0.6.3-1). It has a couple of bug fixes (including a particularly annoying, if minor, one around systemd socket activation that felt very satisfying to get to the bottom of), but I still lack the time to do any of the major changes I would like to. I wrote listadmin3 to allow easy manipulation of moderation queues for Mailman3. It s basic, but it s drastically improved my timeliness on dealing with held messages.

19 December 2023

Matthew Garrett: Making SSH host certificates more usable

Earlier this year, after Github accidentally committed their private RSA SSH host key to a public repository, I wrote about how better support for SSH host certificates would allow this sort of situation to be handled in a user-transparent way without any negative impact on security. I was hoping that someone would read this and be inspired to fix the problem but sadly that didn't happen so I've actually written some code myself.

The core part of this is straightforward - if a server presents you with a certificate associated with a host key, then make the trust in that host be whoever signed the certificate rather than just trusting the host key. This means that if someone needs to replace the host key for any reason (such as, for example, them having published the private half), you can replace the host key with a new key and a new certificate, and as long as the new certificate is signed by the same key that the previous certificate was, you'll trust the new key and key rotation can be carried out without any user errors. Hurrah!

So obviously I wrote that bit and then thought about the failure modes and it turns out there's an obvious one - if an attacker obtained both the private key and the certificate, what stops them from continuing to use it? The certificate isn't a secret, so we basically have to assume that anyone who possesses the private key has access to it. We may have silently transitioned to a new host key on the legitimate servers, but a hostile actor able to MITM a user can keep on presenting the old key and the old certificate until it expires.

There's two ways to deal with this - either have short-lived certificates (ie, issue a new certificate every 24 hours or so even if you haven't changed the key, and specify that the certificate is invalid after those 24 hours), or have a mechanism to revoke the certificates. The former is viable if you have a very well-engineered certificate issuing operation, but still leaves a window for an attacker to make use of the certificate before it expires. The latter is something SSH has support for, but the spec doesn't define any mechanism for distributing revocation data.

So, I've implemented a new SSH protocol extension that allows a host to send a key revocation list to a client. The idea is that the client authenticates to the server, receives a key revocation list, and will no longer trust any certificates that are contained within that list. This seems simple enough, but a naive implementation opens the client to various DoS attacks. For instance, if you simply revoke any key contained within the received KRL, a hostile server could revoke any certificates that were otherwise trusted by the client. The easy way around this is for the client to ensure that any revoked keys are associated with the same CA that signed the host certificate - that way a compromised host can only revoke certificates associated with that CA, and can't interfere with anyone else.

Unfortunately that still means that a single compromised host can still trigger revocation of certificates inside that trust domain (ie, a compromised host a.test.com could push a KRL that invalidated the certificate for b.test.com), because there's no way in the KRL format to indicate that a given revocation is associated with a specific hostname. This means we need a mechanism to verify that the KRL update is legitimate, and the easiest way to handle that is to sign it. The KRL format specifies an in-band signature but this was deprecated earlier this year - instead KRLs are supposed to be signed with the sshsig format. But we control both the server and the client, which means it's easy enough to send a detached signature as part of the extension data.

Putting this all together: you ssh to a server you've never contacted before, and it presents you with a host certificate. Instead of the host key being added to known_hosts, the CA key associated with the certificate is added. From now on, if you ssh to that host and it presents a certificate signed by that CA, it'll be trusted. Optionally, the host can also send you a KRL and a signature. If the signature is generated by the CA key that you already trust, any certificates in that KRL associated with that CA key will be incorporated into local storage. The expected flow if a key is compromised is that the owner of the host generates a new keypair, obtains a new certificate for the new key, and adds the old certificate to a KRL that is signed with the CA key. The next time the user connects to that host, they receive the new key and new certificate, trust it because it's signed by the same CA key, and also receive a KRL signed with the same CA that revokes trust in the old certificate.

Obviously this breaks down if a user is MITMed with a compromised key and certificate immediately after the host is compromised - they'll see a legitimate certificate and won't receive any revocation list, so will trust the host. But this is the same failure mode that would occur in the absence of keys, where the attacker simply presents the compromised key to the client before trust in the new key has been created. This seems no worse than the status quo, but means that most users will seamlessly transition to a new key and revoke trust in the old key with no effort on their part.

The work in progress tree for this is here - at the point of writing I've merely implemented this and made sure it builds, not verified that it actually works or anything. Cleanup should happen over the next few days, and I'll propose this to upstream if it doesn't look like there's any showstopper design issues.

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5 December 2023

Matthew Garrett: Why does Gnome fingerprint unlock not unlock the keyring?

There's a decent number of laptops with fingerprint readers that are supported by Linux, and Gnome has some nice integration to make use of that for authentication purposes. But if you log in with a fingerprint, the moment you start any app that wants to access stored passwords you'll get a prompt asking you to type in your password, which feels like it somewhat defeats the point. Mac users don't have this problem - authenticate with TouchID and all your passwords are available after login. Why the difference?

Fingerprint detection can be done in two primary ways. The first is that a fingerprint reader is effectively just a scanner - it passes a graphical representation of the fingerprint back to the OS and the OS decides whether or not it matches an enrolled finger. The second is for the fingerprint reader to make that determination itself, either storing a set of trusted fingerprints in its own storage or supporting being passed a set of encrypted images to compare against. Fprint supports both of these, but note that in both cases all that we get at the end of the day is a statement of "The fingerprint matched" or "The fingerprint didn't match" - we can't associate anything else with that.

Apple's solution involves wiring the fingerprint reader to a secure enclave, an independently running security chip that can store encrypted secrets or keys and only release them under pre-defined circumstances. Rather than the fingerprint reader providing information directly to the OS, it provides it to the secure enclave. If the fingerprint matches, the secure enclave can then provide some otherwise secret material to the OS. Critically, if the fingerprint doesn't match, the enclave will never release this material.

And that's the difference. When you perform TouchID authentication, the secure enclave can decide to release a secret that can be used to decrypt your keyring. We can't easily do this under Linux because we don't have an interface to store those secrets. The secret material can't just be stored on disk - that would allow anyone who had access to the disk to use that material to decrypt the keyring and get access to the passwords, defeating the object. We can't use the TPM because there's no secure communications channel between the fingerprint reader and the TPM, so we can't configure the TPM to release secrets only if an associated fingerprint is provided.

So the simple answer is that fingerprint unlock doesn't unlock the keyring because there's currently no secure way to do that. It's not intransigence on the part of the developers or a conspiracy to make life more annoying. It'd be great to fix it, but I don't see an easy way to do so at the moment.

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26 November 2023

Ian Jackson: Hacking my filter coffee machine

I hacked my coffee machine to let me turn it on from upstairs in bed :-). Read on for explanation, circuit diagrams, 3D models, firmware source code, and pictures. Background: the Morphy Richards filter coffee machine I have a Morphy Richards filter coffee machine. It makes very good coffee. But the display and firmware are quite annoying: Also, I m lazy and wanted to be able to cause coffee to exist from upstairs in bed, without having to make a special trip down just to turn the machine on. Planning My original feeling was I can t be bothered dealing with the coffee machine innards so I thought I would make a mechanical contraption to physically press the coffee machine s on button. I could have my contraption press the button to turn the machine on (timed, or triggered remotely), and then periodically in pairs to reset the 25-minute keep-warm timer. But a friend pointed me at a blog post by Andy Bradford, where Andy recounts modifying his coffee machine, adding an ESP8266 and connecting it to his MQTT-based Home Assistant setup. I looked at the pictures and they looked very similar to my machine. I decided to take a look inside. Inside the Morphy Richards filter coffee machine My coffee machine seemed to be very similar to Andy s. His disassembly report was very helpful. Inside I found the high-voltage parts with the heating elements, and the front panel with the display and buttons. I spent a while poking about, masuring things, and so on. Unexpected electrical hazard At one point I wanted to use my storage oscilloscope to capture the duration and amplitude of the beep signal. I needed to connect the scope ground to the UI board s ground plane, but then when I switched the coffee machine on at the wall socket, it tripped the house s RCD. It turns out that the low voltage UI board is coupled to the mains. In my setting, there s an offset of about 8V between the UI board ground plane, and true earth. (In my house the neutral is about 2-3V away from true earth.) This alarmed me rather. To me, this means that my modifications needed to still properly electrically isolate everything connected to the UI board from anything external to the coffee machine s housing. In Andy s design, I think the internal UI board ground plane is directly brought out to an external USB-A connector. This means that if there were a neutral fault, the USB-A connector would be at live potential, possibly creating an electrocution or fire hazard. I made a comment in Andy Bradford s blog, reporting this issue, but it doesn t seem to have appeared. This is all quite alarming. I hope Andy is OK! Design approach I don t have an MQTT setup at home, or an installation of Home Assistant. I didn t feel like adding a lot of complicated software to my life, if I could avoid it. Nor did I feel like writing a web UI myself. I ve done that before, but I m lazy and in this case my requirements were quite modest. Also, the need for electrical isolation would further complicate any attempt to do something sophisticated (that could, for example, sense the state of the coffee machine). I already had a Tasmota-based cloud-free smart plug, which controls the fairy lights on our gazebo. We just operate that through its web UI. So, I decided I would add a small and stupid microcontroller. The microcontroller would be powered via a smart plug and an off-the-shelf USB power supply. The microcontroller would have no inputs. It would simply simulate an on button press once at startup, and thereafter two presses every 24 minutes. After the 4th double press the microcontroller would stop, leaving the coffee machine to time out itself, after a total period of about 2h. Implementation - hardware I used a DigiSpark board with an ATTiny85. One of the GPIOs is connected to an optoisolator, whose output transistor is wired across the UI board s on button. circuit diagram; board layout diagram; (click for diagram scans as pdfs). The DigiSpark has just a USB tongue, which is very wobbly in a normal USB socket. I designed a 3D printed case which also had an approximation of the rest of the USB A plug. The plug is out of spec; our printer won t go fine enough - and anyway, the shield is supposed to be metal, not fragile plastic. But it fit in the USB PSU I was using, satisfactorily if a bit stiffly, and also into the connector for programming via my laptop. Inside the coffee machine, there s the boundary between the original, coupled to mains, UI board, and the isolated low voltage of the microcontroller. I used a reasonably substantial cable to bring out the low voltage connection, past all the other hazardous innards, to make sure it stays isolated. I added a drain power supply resistor on another of the GPIOs. This is enabled, with a draw of about 30mA, when the microcontroller is soon going to off / on cycle the coffee machine. That reduces the risk that the user will turn off the smart plug, and turn off the machine, but that the microcontroller turns the coffee machine back on again using the remaining power from USB PSU. Empirically in my setup it reduces the time from smart plug off to microcontroller stops from about 2-3s to more like 1s. Optoisolator board (inside coffee machine) pictures (Click through for full size images.) optoisolator board, front; optoisolator board, rear; optoisolator board, fitted. Microcontroller board (in USB-plug-ish housing) pictures microcontroller board, component side; microcontroller board, wiring side, part fitted; microcontroller in USB-plug-ish housing. Implementation - software I originally used the Arduino IDE, writing my program in C. I had a bad time with that and rewrote it in Rust. The firmware is in a repository on Debian s gitlab Results I can now cause the coffee to start, from my phone. It can be programmed more than 12h in advance. And it stays warm until we ve drunk it. UI is worse There s one aspect of the original Morphy Richards machine that I haven t improved: the user interface is still poor. Indeed, it s now even worse: To turn the machine on, you probably want to turn on the smart plug instead. Unhappily, the power button for that is invisible in its installed location. In particular, in the usual case, if you want to turn it off, you should ideally turn off both the smart plug (which can be done with the button on it) and the coffee machine itself. If you forget to turn off the smart plug, the machine can end up being turned on, very briefly, a handful of times, over the next hour or two. Epilogue We had used the new features a handful of times when one morning the coffee machine just wouldn t make coffee. The UI showed it turning on, but it wouldn t get hot, so no coffee. I thought oh no, I ve broken it! But, on investigation, I found that the machine s heating element was open circuit (ie, completely broken). I didn t mess with that part. So, hooray! Not my fault. Probably, just being inverted a number of times and generally lightly jostled, had precipitated a latent fault. The machine was a number of years old. Happily I found a replacement, identical, machine, online. I ve transplanted my modification and now it all works well. Bonus pictures (Click through for full size images.) probing the innards; machine base showing new cable route.
edited 2023-11-26 14:59 UTC in an attempt to fix TOC links


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12 November 2023

Petter Reinholdtsen: New and improved sqlcipher in Debian for accessing Signal database

For a while now I wanted to have direct access to the Signal database of messages and channels of my Desktop edition of Signal. I prefer the enforced end to end encryption of Signal these days for my communication with friends and family, to increase the level of safety and privacy as well as raising the cost of the mass surveillance government and non-government entities practice these days. In August I came across a nice recipe on how to use sqlcipher to extract statistics from the Signal database explaining how to do this. Unfortunately this did not work with the version of sqlcipher in Debian. The sqlcipher package is a "fork" of the sqlite package with added support for encrypted databases. Sadly the current Debian maintainer announced more than three years ago that he did not have time to maintain sqlcipher, so it seemed unlikely to be upgraded by the maintainer. I was reluctant to take on the job myself, as I have very limited experience maintaining shared libraries in Debian. After waiting and hoping for a few months, I gave up the last week, and set out to update the package. In the process I orphaned it to make it more obvious for the next person looking at it that the package need proper maintenance. The version in Debian was around five years old, and quite a lot of changes had taken place upstream into the Debian maintenance git repository. After spending a few days importing the new upstream versions, realising that upstream did not care much for SONAME versioning as I saw library symbols being both added and removed with minor version number changes to the project, I concluded that I had to do a SONAME bump of the library package to avoid surprising the reverse dependencies. I even added a simple autopkgtest script to ensure the package work as intended. Dug deep into the hole of learning shared library maintenance, I set out a few days ago to upload the new version to Debian experimental to see what the quality assurance framework in Debian had to say about the result. The feedback told me the pacakge was not too shabby, and yesterday I uploaded the latest version to Debian unstable. It should enter testing today or tomorrow, perhaps delayed by a small library transition. Armed with a new version of sqlcipher, I can now have a look at the SQL database in ~/.config/Signal/sql/db.sqlite. First, one need to fetch the encryption key from the Signal configuration using this simple JSON extraction command:
/usr/bin/jq -r '."key"' ~/.config/Signal/config.json
Assuming the result from that command is 'secretkey', which is a hexadecimal number representing the key used to encrypt the database. Next, one can now connect to the database and inject the encryption key for access via SQL to fetch information from the database. Here is an example dumping the database structure:
% sqlcipher ~/.config/Signal/sql/db.sqlite
sqlite> PRAGMA key = "x'secretkey'";
sqlite> .schema
CREATE TABLE sqlite_stat1(tbl,idx,stat);
CREATE TABLE conversations(
      id STRING PRIMARY KEY ASC,
      json TEXT,
      active_at INTEGER,
      type STRING,
      members TEXT,
      name TEXT,
      profileName TEXT
    , profileFamilyName TEXT, profileFullName TEXT, e164 TEXT, serviceId TEXT, groupId TEXT, profileLastFetchedAt INTEGER);
CREATE TABLE identityKeys(
      id STRING PRIMARY KEY ASC,
      json TEXT
    );
CREATE TABLE items(
      id STRING PRIMARY KEY ASC,
      json TEXT
    );
CREATE TABLE sessions(
      id TEXT PRIMARY KEY,
      conversationId TEXT,
      json TEXT
    , ourServiceId STRING, serviceId STRING);
CREATE TABLE attachment_downloads(
    id STRING primary key,
    timestamp INTEGER,
    pending INTEGER,
    json TEXT
  );
CREATE TABLE sticker_packs(
    id TEXT PRIMARY KEY,
    key TEXT NOT NULL,
    author STRING,
    coverStickerId INTEGER,
    createdAt INTEGER,
    downloadAttempts INTEGER,
    installedAt INTEGER,
    lastUsed INTEGER,
    status STRING,
    stickerCount INTEGER,
    title STRING
  , attemptedStatus STRING, position INTEGER DEFAULT 0 NOT NULL, storageID STRING, storageVersion INTEGER, storageUnknownFields BLOB, storageNeedsSync
      INTEGER DEFAULT 0 NOT NULL);
CREATE TABLE stickers(
    id INTEGER NOT NULL,
    packId TEXT NOT NULL,
    emoji STRING,
    height INTEGER,
    isCoverOnly INTEGER,
    lastUsed INTEGER,
    path STRING,
    width INTEGER,
    PRIMARY KEY (id, packId),
    CONSTRAINT stickers_fk
      FOREIGN KEY (packId)
      REFERENCES sticker_packs(id)
      ON DELETE CASCADE
  );
CREATE TABLE sticker_references(
    messageId STRING,
    packId TEXT,
    CONSTRAINT sticker_references_fk
      FOREIGN KEY(packId)
      REFERENCES sticker_packs(id)
      ON DELETE CASCADE
  );
CREATE TABLE emojis(
    shortName TEXT PRIMARY KEY,
    lastUsage INTEGER
  );
CREATE TABLE messages(
        rowid INTEGER PRIMARY KEY ASC,
        id STRING UNIQUE,
        json TEXT,
        readStatus INTEGER,
        expires_at INTEGER,
        sent_at INTEGER,
        schemaVersion INTEGER,
        conversationId STRING,
        received_at INTEGER,
        source STRING,
        hasAttachments INTEGER,
        hasFileAttachments INTEGER,
        hasVisualMediaAttachments INTEGER,
        expireTimer INTEGER,
        expirationStartTimestamp INTEGER,
        type STRING,
        body TEXT,
        messageTimer INTEGER,
        messageTimerStart INTEGER,
        messageTimerExpiresAt INTEGER,
        isErased INTEGER,
        isViewOnce INTEGER,
        sourceServiceId TEXT, serverGuid STRING NULL, sourceDevice INTEGER, storyId STRING, isStory INTEGER
        GENERATED ALWAYS AS (type IS 'story'), isChangeCreatedByUs INTEGER NOT NULL DEFAULT 0, isTimerChangeFromSync INTEGER
        GENERATED ALWAYS AS (
          json_extract(json, '$.expirationTimerUpdate.fromSync') IS 1
        ), seenStatus NUMBER default 0, storyDistributionListId STRING, expiresAt INT
        GENERATED ALWAYS
        AS (ifnull(
          expirationStartTimestamp + (expireTimer * 1000),
          9007199254740991
        )), shouldAffectActivity INTEGER
        GENERATED ALWAYS AS (
          type IS NULL
          OR
          type NOT IN (
            'change-number-notification',
            'contact-removed-notification',
            'conversation-merge',
            'group-v1-migration',
            'keychange',
            'message-history-unsynced',
            'profile-change',
            'story',
            'universal-timer-notification',
            'verified-change'
          )
        ), shouldAffectPreview INTEGER
        GENERATED ALWAYS AS (
          type IS NULL
          OR
          type NOT IN (
            'change-number-notification',
            'contact-removed-notification',
            'conversation-merge',
            'group-v1-migration',
            'keychange',
            'message-history-unsynced',
            'profile-change',
            'story',
            'universal-timer-notification',
            'verified-change'
          )
        ), isUserInitiatedMessage INTEGER
        GENERATED ALWAYS AS (
          type IS NULL
          OR
          type NOT IN (
            'change-number-notification',
            'contact-removed-notification',
            'conversation-merge',
            'group-v1-migration',
            'group-v2-change',
            'keychange',
            'message-history-unsynced',
            'profile-change',
            'story',
            'universal-timer-notification',
            'verified-change'
          )
        ), mentionsMe INTEGER NOT NULL DEFAULT 0, isGroupLeaveEvent INTEGER
        GENERATED ALWAYS AS (
          type IS 'group-v2-change' AND
          json_array_length(json_extract(json, '$.groupV2Change.details')) IS 1 AND
          json_extract(json, '$.groupV2Change.details[0].type') IS 'member-remove' AND
          json_extract(json, '$.groupV2Change.from') IS NOT NULL AND
          json_extract(json, '$.groupV2Change.from') IS json_extract(json, '$.groupV2Change.details[0].aci')
        ), isGroupLeaveEventFromOther INTEGER
        GENERATED ALWAYS AS (
          isGroupLeaveEvent IS 1
          AND
          isChangeCreatedByUs IS 0
        ), callId TEXT
        GENERATED ALWAYS AS (
          json_extract(json, '$.callId')
        ));
CREATE TABLE sqlite_stat4(tbl,idx,neq,nlt,ndlt,sample);
CREATE TABLE jobs(
        id TEXT PRIMARY KEY,
        queueType TEXT STRING NOT NULL,
        timestamp INTEGER NOT NULL,
        data STRING TEXT
      );
CREATE TABLE reactions(
        conversationId STRING,
        emoji STRING,
        fromId STRING,
        messageReceivedAt INTEGER,
        targetAuthorAci STRING,
        targetTimestamp INTEGER,
        unread INTEGER
      , messageId STRING);
CREATE TABLE senderKeys(
        id TEXT PRIMARY KEY NOT NULL,
        senderId TEXT NOT NULL,
        distributionId TEXT NOT NULL,
        data BLOB NOT NULL,
        lastUpdatedDate NUMBER NOT NULL
      );
CREATE TABLE unprocessed(
        id STRING PRIMARY KEY ASC,
        timestamp INTEGER,
        version INTEGER,
        attempts INTEGER,
        envelope TEXT,
        decrypted TEXT,
        source TEXT,
        serverTimestamp INTEGER,
        sourceServiceId STRING
      , serverGuid STRING NULL, sourceDevice INTEGER, receivedAtCounter INTEGER, urgent INTEGER, story INTEGER);
CREATE TABLE sendLogPayloads(
        id INTEGER PRIMARY KEY ASC,
        timestamp INTEGER NOT NULL,
        contentHint INTEGER NOT NULL,
        proto BLOB NOT NULL
      , urgent INTEGER, hasPniSignatureMessage INTEGER DEFAULT 0 NOT NULL);
CREATE TABLE sendLogRecipients(
        payloadId INTEGER NOT NULL,
        recipientServiceId STRING NOT NULL,
        deviceId INTEGER NOT NULL,
        PRIMARY KEY (payloadId, recipientServiceId, deviceId),
        CONSTRAINT sendLogRecipientsForeignKey
          FOREIGN KEY (payloadId)
          REFERENCES sendLogPayloads(id)
          ON DELETE CASCADE
      );
CREATE TABLE sendLogMessageIds(
        payloadId INTEGER NOT NULL,
        messageId STRING NOT NULL,
        PRIMARY KEY (payloadId, messageId),
        CONSTRAINT sendLogMessageIdsForeignKey
          FOREIGN KEY (payloadId)
          REFERENCES sendLogPayloads(id)
          ON DELETE CASCADE
      );
CREATE TABLE preKeys(
        id STRING PRIMARY KEY ASC,
        json TEXT
      , ourServiceId NUMBER
        GENERATED ALWAYS AS (json_extract(json, '$.ourServiceId')));
CREATE TABLE signedPreKeys(
        id STRING PRIMARY KEY ASC,
        json TEXT
      , ourServiceId NUMBER
        GENERATED ALWAYS AS (json_extract(json, '$.ourServiceId')));
CREATE TABLE badges(
        id TEXT PRIMARY KEY,
        category TEXT NOT NULL,
        name TEXT NOT NULL,
        descriptionTemplate TEXT NOT NULL
      );
CREATE TABLE badgeImageFiles(
        badgeId TEXT REFERENCES badges(id)
          ON DELETE CASCADE
          ON UPDATE CASCADE,
        'order' INTEGER NOT NULL,
        url TEXT NOT NULL,
        localPath TEXT,
        theme TEXT NOT NULL
      );
CREATE TABLE storyReads (
        authorId STRING NOT NULL,
        conversationId STRING NOT NULL,
        storyId STRING NOT NULL,
        storyReadDate NUMBER NOT NULL,
        PRIMARY KEY (authorId, storyId)
      );
CREATE TABLE storyDistributions(
        id STRING PRIMARY KEY NOT NULL,
        name TEXT,
        senderKeyInfoJson STRING
      , deletedAtTimestamp INTEGER, allowsReplies INTEGER, isBlockList INTEGER, storageID STRING, storageVersion INTEGER, storageUnknownFields BLOB, storageNeedsSync INTEGER);
CREATE TABLE storyDistributionMembers(
        listId STRING NOT NULL REFERENCES storyDistributions(id)
          ON DELETE CASCADE
          ON UPDATE CASCADE,
        serviceId STRING NOT NULL,
        PRIMARY KEY (listId, serviceId)
      );
CREATE TABLE uninstalled_sticker_packs (
        id STRING NOT NULL PRIMARY KEY,
        uninstalledAt NUMBER NOT NULL,
        storageID STRING,
        storageVersion NUMBER,
        storageUnknownFields BLOB,
        storageNeedsSync INTEGER NOT NULL
      );
CREATE TABLE groupCallRingCancellations(
        ringId INTEGER PRIMARY KEY,
        createdAt INTEGER NOT NULL
      );
CREATE TABLE IF NOT EXISTS 'messages_fts_data'(id INTEGER PRIMARY KEY, block BLOB);
CREATE TABLE IF NOT EXISTS 'messages_fts_idx'(segid, term, pgno, PRIMARY KEY(segid, term)) WITHOUT ROWID;
CREATE TABLE IF NOT EXISTS 'messages_fts_content'(id INTEGER PRIMARY KEY, c0);
CREATE TABLE IF NOT EXISTS 'messages_fts_docsize'(id INTEGER PRIMARY KEY, sz BLOB);
CREATE TABLE IF NOT EXISTS 'messages_fts_config'(k PRIMARY KEY, v) WITHOUT ROWID;
CREATE TABLE edited_messages(
        messageId STRING REFERENCES messages(id)
          ON DELETE CASCADE,
        sentAt INTEGER,
        readStatus INTEGER
      , conversationId STRING);
CREATE TABLE mentions (
        messageId REFERENCES messages(id) ON DELETE CASCADE,
        mentionAci STRING,
        start INTEGER,
        length INTEGER
      );
CREATE TABLE kyberPreKeys(
        id STRING PRIMARY KEY NOT NULL,
        json TEXT NOT NULL, ourServiceId NUMBER
        GENERATED ALWAYS AS (json_extract(json, '$.ourServiceId')));
CREATE TABLE callsHistory (
        callId TEXT PRIMARY KEY,
        peerId TEXT NOT NULL, -- conversation id (legacy)   uuid   groupId   roomId
        ringerId TEXT DEFAULT NULL, -- ringer uuid
        mode TEXT NOT NULL, -- enum "Direct"   "Group"
        type TEXT NOT NULL, -- enum "Audio"   "Video"   "Group"
        direction TEXT NOT NULL, -- enum "Incoming"   "Outgoing
        -- Direct: enum "Pending"   "Missed"   "Accepted"   "Deleted"
        -- Group: enum "GenericGroupCall"   "OutgoingRing"   "Ringing"   "Joined"   "Missed"   "Declined"   "Accepted"   "Deleted"
        status TEXT NOT NULL,
        timestamp INTEGER NOT NULL,
        UNIQUE (callId, peerId) ON CONFLICT FAIL
      );
[ dropped all indexes to save space in this blog post ]
CREATE TRIGGER messages_on_view_once_update AFTER UPDATE ON messages
      WHEN
        new.body IS NOT NULL AND new.isViewOnce = 1
      BEGIN
        DELETE FROM messages_fts WHERE rowid = old.rowid;
      END;
CREATE TRIGGER messages_on_insert AFTER INSERT ON messages
      WHEN new.isViewOnce IS NOT 1 AND new.storyId IS NULL
      BEGIN
        INSERT INTO messages_fts
          (rowid, body)
        VALUES
          (new.rowid, new.body);
      END;
CREATE TRIGGER messages_on_delete AFTER DELETE ON messages BEGIN
        DELETE FROM messages_fts WHERE rowid = old.rowid;
        DELETE FROM sendLogPayloads WHERE id IN (
          SELECT payloadId FROM sendLogMessageIds
          WHERE messageId = old.id
        );
        DELETE FROM reactions WHERE rowid IN (
          SELECT rowid FROM reactions
          WHERE messageId = old.id
        );
        DELETE FROM storyReads WHERE storyId = old.storyId;
      END;
CREATE VIRTUAL TABLE messages_fts USING fts5(
        body,
        tokenize = 'signal_tokenizer'
      );
CREATE TRIGGER messages_on_update AFTER UPDATE ON messages
      WHEN
        (new.body IS NULL OR old.body IS NOT new.body) AND
         new.isViewOnce IS NOT 1 AND new.storyId IS NULL
      BEGIN
        DELETE FROM messages_fts WHERE rowid = old.rowid;
        INSERT INTO messages_fts
          (rowid, body)
        VALUES
          (new.rowid, new.body);
      END;
CREATE TRIGGER messages_on_insert_insert_mentions AFTER INSERT ON messages
      BEGIN
        INSERT INTO mentions (messageId, mentionAci, start, length)
        
    SELECT messages.id, bodyRanges.value ->> 'mentionAci' as mentionAci,
      bodyRanges.value ->> 'start' as start,
      bodyRanges.value ->> 'length' as length
    FROM messages, json_each(messages.json ->> 'bodyRanges') as bodyRanges
    WHERE bodyRanges.value ->> 'mentionAci' IS NOT NULL
  
        AND messages.id = new.id;
      END;
CREATE TRIGGER messages_on_update_update_mentions AFTER UPDATE ON messages
      BEGIN
        DELETE FROM mentions WHERE messageId = new.id;
        INSERT INTO mentions (messageId, mentionAci, start, length)
        
    SELECT messages.id, bodyRanges.value ->> 'mentionAci' as mentionAci,
      bodyRanges.value ->> 'start' as start,
      bodyRanges.value ->> 'length' as length
    FROM messages, json_each(messages.json ->> 'bodyRanges') as bodyRanges
    WHERE bodyRanges.value ->> 'mentionAci' IS NOT NULL
  
        AND messages.id = new.id;
      END;
sqlite>
Finally I have the tool needed to inspect and process Signal messages that I need, without using the vendor provided client. Now on to transforming it to a more useful format. As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

7 November 2023

Matthew Palmer: PostgreSQL Encryption: The Available Options

On an episode of Postgres FM, the hosts had a (very brief) discussion of data encryption in PostgreSQL. While Postgres FM is a podcast well worth a subscribe, the hosts aren t data security experts, and so as someone who builds a queryable database encryption system, I found the coverage to be somewhat lacking. I figured I d provide a more complete survey of the available options for PostgreSQL-related data encryption.

The Status Quo By default, when you install PostgreSQL, there is no data encryption at all. That means that anyone who gets access to any part of the system can read all the data they have access to. This is, of course, not peculiar to PostgreSQL: basically everything works much the same way. What s stopping an attacker from nicking off with all your data is the fact that they can t access the database at all. The things that are acting as protection are perimeter defences, like putting the physical equipment running the server in a secure datacenter, firewalls to prevent internet randos connecting to the database, and strong passwords. This is referred to as tortoise security it s tough on the outside, but soft on the inside. Once that outer shell is cracked, the delicious, delicious data is ripe for the picking, and there s absolutely nothing to stop a miscreant from going to town and making off with everything. It s a good idea to plan your defenses on the assumption you re going to get breached sooner or later. Having good defence-in-depth includes denying the attacker to your data even if they compromise the database. This is where encryption comes in.

Storage-Layer Defences: Disk / Volume Encryption To protect against the compromise of the storage that your database uses (physical disks, EBS volumes, and the like), it s common to employ encryption-at-rest, such as full-disk encryption, or volume encryption. These mechanisms protect against offline attacks, but provide no protection while the system is actually running. And therein lies the rub: your database is always running, so encryption at rest typically doesn t provide much value. If you re running physical systems, disk encryption is essential, but more to prevent accidental data loss, due to things like failing to wipe drives before disposing of them, rather than physical theft. In systems where volume encryption is only a tickbox away, it s also worth enabling, if only to prevent inane questions from your security auditors. Relying solely on storage-layer defences, though, is very unlikely to provide any appreciable value in preventing data loss.

Database-Layer Defences: Transparent Database Encryption If you ve used proprietary database systems in high-security environments, you might have come across Transparent Database Encryption (TDE). There are also a couple of proprietary extensions for PostgreSQL that provide this functionality. TDE is essentially encryption-at-rest implemented inside the database server. As such, it has much the same drawbacks as disk encryption: few real-world attacks are thwarted by it. There is a very small amount of additional protection, in that physical level backups (as produced by pg_basebackup) are protected, but the vast majority of attacks aren t stopped by TDE. Any attacker who can access the database while it s running can just ask for an SQL-level dump of the stored data, and they ll get the unencrypted data quick as you like.

Application-Layer Defences: Field Encryption If you want to take the database out of the threat landscape, you really need to encrypt sensitive data before it even gets near the database. This is the realm of field encryption, more commonly known as application-level encryption. This technique involves encrypting each field of data before it is sent to be stored in the database, and then decrypting it again after it s retrieved from the database. Anyone who gets the data from the database directly, whether via a backup or a direct connection, is out of luck: they can t decrypt the data, and therefore it s worthless. There are, of course, some limitations of this technique. For starters, every ORM and data mapper out there has rolled their own encryption format, meaning that there s basically zero interoperability. This isn t a problem if you build everything that accesses the database using a single framework, but if you ever feel the need to migrate, or use the database from multiple codebases, you re likely in for a rough time. The other big problem of traditional application-level encryption is that, when the database can t understand what data its storing, it can t run queries against that data. So if you want to encrypt, say, your users dates of birth, but you also need to be able to query on that field, you need to choose between one or the other: you can t have both at the same time. You may think to yourself, but this isn t any good, an attacker that breaks into my application can still steal all my data! . That is true, but security is never binary. The name of the game is reducing the attack surface, making it harder for an attacker to succeed. If you leave all the data unencrypted in the database, an attacker can steal all your data by breaking into the database or by breaking into the application. Encrypting the data reduces the attacker s options, and allows you to focus your resources on hardening the application against attack, safe in the knowledge that an attacker who gets into the database directly isn t going to get anything valuable.

Sidenote: The Curious Case of pg_crypto PostgreSQL ships a contrib module called pg_crypto, which provides encryption and decryption functions. This sounds ideal to use for encrypting data within our applications, as it s available no matter what we re using to write our application. It avoids the problem of framework-specific cryptography, because you call the same PostgreSQL functions no matter what language you re using, which produces the same output. However, I don t recommend ever using pg_crypto s data encryption functions, and I doubt you will find many other cryptographic engineers who will, either. First up, and most horrifyingly, it requires you to pass the long-term keys to the database server. If there s an attacker actively in the database server, they can capture the keys as they come in, which means all the data encrypted using that key is exposed. Sending the keys can also result in the keys ending up in query logs, both on the client and server, which is obviously a terrible result. Less scary, but still very concerning, is that pg_crypto s available cryptography is, to put it mildly, antiquated. We have a lot of newer, safer, and faster techniques for data encryption, that aren t available in pg_crypto. This means that if you do use it, you re leaving a lot on the table, and need to have skilled cryptographic engineers on hand to avoid the potential pitfalls. In short: friends don t let friends use pg_crypto.

The Future: Enquo All this brings us to the project I run: Enquo. It takes application-layer encryption to a new level, by providing a language- and framework-agnostic cryptosystem that also enables encrypted data to be efficiently queried by the database. So, you can encrypt your users dates of birth, in such a way that anyone with the appropriate keys can query the database to return, say, all users over the age of 18, but an attacker just sees unintelligible gibberish. This should greatly increase the amount of data that can be encrypted, and as the Enquo project expands its available data types and supported languages, the coverage of encrypted data will grow and grow. My eventual goal is to encrypt all data, all the time. If this appeals to you, visit enquo.org to use or contribute to the open source project, or EnquoDB.com for commercial support and hosted database options.

2 November 2023

Reproducible Builds: Farewell from the Reproducible Builds Summit 2023!

Farewell from the Reproducible Builds summit, which just took place in Hamburg, Germany: This year, we were thrilled to host the seventh edition of this exciting event. Topics covered this year included:

as well as countless informal discussions and hacking sessions into the night. Projects represented at the venue included:
Debian, openSUSE, QubesOS, GNU Guix, Arch Linux, phosh, Mobian, PureOS, JustBuild, LibreOffice, Warpforge, OpenWrt, F-Droid, NixOS, ElectroBSD, Apache Security, Buildroot, Systemd, Apache Maven, Fedora, Privoxy, CHAINS (KTH Royal Institute of Technology), coreboot, GitHub, Tor Project, Ubuntu, rebuilderd, repro-env, spytrap-adb, arch-repro-status, etc.

A huge thanks to our sponsors and partners for making the event possible:
Aspiration

Event facilitation

Mullvad

Platinum sponsor


If you weren t able to make it this year, don t worry; just look out for an announcement in 2024 for the next event.

22 October 2023

Aigars Mahinovs: Figuring out finances part 3

So now that I have something that looks very much like a budgeting setup going, I am going to .. delete it! Why? Well, at the end of the last part of this, the Firefly III instance was running on a tiny Debian server in a Docker container right next to another Docker container that is running the main user of this server - a Home Assistant instance that has been managing my home for several years already. So why change that? See, there is one bit of knowledge that is very crucial to your Home Assistant experience, which is not really emphasised enough in the Home Assistant documentation. In fact back when I was getting into the Home Assistant both the main documentation and basically all the guides around were just coming off the hype of Docker disrupting everything and that is a big reason why everyone suggested to install and use Home Assistant as a Docker container on top of any kind of stable OS. In fact I used to run it for years on my TerraMaster NAS, just so that I don't have a separate home server running 24/7 at home and just have everything inside the very compact NAS case. So here is the thing you NEED to know - Home Assistant Container is DEMO version of Home Assistant! If you want to have a full Home Assistant experience and use the knowledge of the huge community around the HA space, you have to use the Home Assistant OS. Ideally on dedicated hardware. Ideally on HA Green box, but any tiny PC would also work great. Raspberry Pi 4+ is common, but quite weak as the network size grows and especially the SD card for storage gets old very fast. Get a real small x86 PC with at least 4Gb RAM and a NVME SSD (eMMC is fine too). You want to have an Ethernet port and a few free USB ports. I would also suggest immediately getting HA SkyConnect adapter that can do Zigbee networking and will do Matter soon (tm). I am making do with a SonOff Zigbee gateway, but it is quite hacky to get working and your whole Zigbee communication breaks down if the WiFi goes down - suboptimal. So I took a backup of the Home Assistant instance using it's build-in tools. I took an export of my fully configured Firefly III instance and proceeded to wipe the drive of the NUC. That was not a smart idea. :D On the Home Assitant side I was really frustrated by the documentation that was really focused on users that are (likely) using Windows and are using an SD card in something like Raspberry Pi to get Home Assistant OS running. It recommended downloading Etcher to write the image to the boot medium. That is a really weird piece of software that managed to actually crash consistently when I was trying to run it from Debian Live or Ubuntu Live on my NUC. It took me way too long to give up and try something much simpler - dd. xzcat haos_generic-x86-64-11.0.img.xz dd of=/dev/mmcblk0 bs=1M That just worked, prefectly and really fast. If you want to use a GUI in a live environment, then just using the gnome-disk-utility ("Disks" in Gnome menu) and using the "Restore Disk Image ..." on a partition would work just as well. It even supports decompressing the XZ images directly while writing. But that image is small, will it not have a ton of unused disk space behind the fixed install partition? Yes, it will ... until first boot. The HA OS takes over the empty space after its install partition on the first boot-up and just grows its main partition to take up all the remaining space. Smart. After first boot is completed, the first boot wizard can be accessed via your web browser and one of the prominent buttons there is restoring from backup. So you just give it the backup file and wait. Sadly the restore does not actually give any kind of progress, so your only way to figure out when it is done is opening the same web adress in another browser tab and refresh periodically - after restoring from backup it just boots into the same config at it had before - all the settings, all the devices, all the history is preserved. Even authentification tokens are preserved so if yu had a Home Assitant Mobile installed on your phone (both for remote access and to send location info and phone state, like charging, to HA to trigger automations) then it will just suddenly start working again without further actions needed from your side. That is an almost perfect backup/restore experience. The first thing you get for using the OS version of HA is easy automatic update that also automatically takes a backup before upgrade, so if anything breaks you can roll back with one click. There is also a command-line tool that allows to upgrade, but also downgrade ha-core and other modules. I had to use it today as HA version 23.10.4 actually broke support for the Sonoff bridge that I am using to control Zigbee devices, which are like 90% of all smart devices in my home. Really helpful stuff, but not a must have. What is a must have and that you can (really) only get with Home Assistant Operating System are Addons. Some addons are just normal servers you can run alongside HA on the same HA OS server, like MariaDB or Plex or a file server. That is not the most important bit, but even there the software comes pre-configured to use in a home server configuration and has a very simple config UI to pre-configure key settings, like users, passwords and database accesses for MariaDB - you can litereally in a few clicks and few strings make serveral users each with its own access to its own database. Couple more clicks and the DB is running and will be kept restarted in case of failures. But the real gems in the Home Assistant Addon Store are modules that extend Home Assitant core functionality in way that would be really hard or near impossible to configure in Home Assitant Container manually, especially because no documentation has ever existed for such manual config - everyone just tells you to install the addon from HA Addon store or from HACS. Or you can read the addon metadata in various repos and figure out what containers it actually runs with what settings and configs and what hooks it puts into the HA Core to make them cooperate. And then do it all over again when a new version breaks everything 6 months later when you have already forgotten everything. In the Addons that show up immediately after installation are addons to install the new Matter server, a MariaDB and MQTT server (that other addons can use for data storage and message exchange), Z-Wave support and ESPHome integration and very handy File manager that includes editors to edit Home Assitant configs directly in brower and SSH/Terminal addon that boht allows SSH connection and also a web based terminal that gives access to the OS itself and also to a comand line interface, for example, to do package downgrades if needed or see detailed logs. And also there is where you can get the features that are the focus this year for HA developers - voice enablers. However that is only a beginning. Like in Debian you can add additional repositories to expand your list of available addons. Unlike Debian most of the amazing software that is available for Home Assistant is outside the main, official addon store. For now I have added the most popular addon repository - HACS (Home Assistant Community Store) and repository maintained by Alexbelgium. The first includes things like NodeRED (a workflow based automation programming UI), Tailscale/Wirescale for VPN servers, motionEye for CCTV control, Plex for home streaming. HACS also includes a lot of HA UI enhacement modules, like themes, custom UI control panels like Mushroom or mini-graph-card and integrations that provide more advanced functions, but also require more knowledge to use, like Local Tuya - that is harder to set up, but allows fully local control of (normally) cloud-based devices. And it has AppDaemon - basically a Python based automation framework where you put in Python scrips that get run in a special environment where they get fed events from Home Assistant and can trigger back events that can control everything HA can and also do anything Python can do. This I will need to explore later. And the repository by Alex includes the thing that is actually the focus of this blog post (I know :D) - Firefly III addon and Firefly Importer addon that you can then add to your Home Assistant OS with a few clicks. It also has all kinds of addons for NAS management, photo/video server, book servers and Portainer that lets us setup and run any Docker container inside the HA OS structure. HA OS will detect this and warn you about unsupported processes running on your HA OS instance (nice security feature!), but you can just dismiss that. This will be very helpful very soon. This whole environment of OS and containers and apps really made me think - what was missing in Debian that made the talented developers behind all of that to spend the immense time and effor to setup a completely new OS and app infrastructure and develop a completel paraller developer community for Home Assistant apps, interfaces and configurations. Is there anything that can still be done to make HA community and the general open source and Debian community closer together? HA devs are not doing anything wrong: they are using the best open source can provide, they bring it to people whould could not install and use it otherwise, they are contributing fixes and improvements as well. But there must be some way to do this better, together. So I installed MariaDB, create a user and database for Firefly. I installed Firefly III and configured it to use the MariaDB with the web config UI. When I went into the Firefly III web UI I was confronted with the normal wizard to setup a new instance. And no reference to any backup restore. Hmm, ok. Maybe that goes via the Importer? So I make an access token again, configured the Importer to use that, configured the Nordlinger bank connection settings. Then I tried to import the export that I downloaded from Firefly III before. The importer did not auto-recognose the format. Turns out it is just a list of transactions ... It can only be barely useful if you first manually create all the asset accounts with the same names as before and even then you'll again have to deal with resolving the problem of transfers showing up twice. And all of your categories (that have not been used yet) are gone, your automation rules and bills are gone, your budgets and piggy banks are gone. Boooo. It will be easier for me to recreate my account data from bank exports again than to resolve data in that transaction export. Turns out that Firefly III documenation explicitly recommends making a mysqldump of your own and not rely on anything in the app itself for backup purposes. Kind of sad this was not mentioned in the export page that sure looked a lot like a backup :D After doing all that work all over again I needed to make something new not to feel like I wasted days of work for no real gain. So I started solving a problem I had for a while already - how do I add cash transations to the system when I am out of the house with just my phone in the hand? So far my workaround has been just sending myself messages in WhatsApp with the amount and description of any cash expenses. Two solutions are possible: app and bot. There are actually multiple Android-based phone apps that work with Firefly III API to do full financial management from the phone. However, after trying it out, that is not what I will be using most of the time. First of all this requires your Firefly III instance to be accessible from the Internet. Either via direct API access using some port forwarding and secured with HTTPS and good access tokens, or via a VPN server redirect that is installed on both HA and your phone. Tailscale was really easy to get working. But the power has its drawbacks - adding a new cash transaction requires opening the app, choosing new transaction view, entering descriptio, amount, choosing "Cash" as source account and optionally choosing destination expense account, choosing category and budget and then submitting the form to the server. Sadly none of that really works if you have no Internet or bad Internet at the place where you are using cash. And it's just too many steps. Annoying. An easier alternative is setting up a Telegram bot - it is running in a custom Docker container right next to your Firefly (via Portainer) and you talk to it via a custom Telegram chat channel that you create very easily and quickly. And then you can just tell it "Coffee 5" and it will create a transaction from the (default) cash account in 5 amount with description "Coffee". This part also works if you are offline at the moment - the bot will receive the message once you get back online. You can use Telegram bot menu system to edit the transaction to add categories or expense accounts, but this part only work if you are online. And the Firefly instance does not have to be online at all. Really nifty. So next week I will need to write up all the regular payments as bills in Firefly (again) and then I can start writing a Python script to predict my (financial) future!

19 October 2023

Russ Allbery: Review: The Cassini Division

Review: The Cassini Division, by Ken MacLeod
Series: Fall Revolution #3
Publisher: Tor
Copyright: 1998
Printing: August 2000
ISBN: 0-8125-6858-3
Format: Mass market
Pages: 305
The Cassini Division is the third book in the Fall Revolution series and a fairly direct sequel (albeit with different protagonists) to The Stone Canal. This is not a good place to start the series. It's impossible to talk about the plot of this book without discussing the future history of this series, which arguably includes some spoilers for The Star Fraction and The Stone Canal. I don't think the direction of history matters that much in enjoying the previous books, but read the first two books of the series before this review if you want to avoid all spoilers. When the Outwarders uploaded themselves and went fast, they did a lot of strange things: an interstellar probe contrary to all known laws of physics, the disassembly of Ganymede, and the Malley Mile, which plays a significant role in The Stone Canal. They also crashed the Earth. This was not entirely their fault. There were a lot of politics, religious fundamentalism, and plagues in play as well. But the storm of viruses broadcast from their transformed Jupiter shut down essentially all computing equipment on Earth, which set off much of the chaos. The results were catastrophic, and also politically transformative. Now, the Solar Union is a nearly unified anarchosocialist society, with only scattered enclaves of non-cooperators left outside that structure. Ellen May Ngewthu is a leader of the Cassini Division, the bulwark that stands between humans and the Outwarders. The Division ruthlessly destroys any remnant or probe that dares rise out of Jupiter's atmosphere, ensuring that the Outwarders, whatever they have become after untold generations of fast evolution, stay isolated to the one planet they have absorbed. The Division is very good at what they do. But there is a potential gap in that line of defense: there are fast folk in storage at the other end of the Malley Mile, on New Mars, and who knows what the deranged capitalists there will do or what forces they might unleash. The one person who knows a path through the Malley Mile isn't talking, so Ellen goes in search of the next best thing: the non-cooperator scientist Isambard Kingdom Malley. I am now thoroughly annoyed at how politics are handled in this series, and much less confused by the frequency with which MacLeod won Prometheus Awards from the Libertarian Futurist Society. Some of this is my own fault for having too high of hopes for political SF, but nothing in this series so far has convinced me that MacLeod is seriously engaging with political systems. Instead, the world-building to date makes the classic libertarian mistake of thinking societies will happily abandon stability and predictability in favor of their strange definition of freedom. The Solar Union is based on what Ellen calls the true knowledge, which is worth quoting in full so that you know what kind of politics we're talking about:
Life is a process of breaking down and using other matter, and if need be, other life. Therefore, life is aggression, and successful life is successful aggression. Life is the scum of matter, and people are the scum of life. There is nothing but matter, forces, space and time, which together make power. Nothing matters, except what matters to you. Might makes right, and power makes freedom. You are free to do whatever is in your power, and if you want to survive and thrive you had better do whatever is in your interests. If your interests conflict with those of others, let the others pit their power against yours, everyone for theirselves. If your interests coincide with those of others, let them work together with you, and against the rest. We are what we eat, and we eat everything. All that you really value, and the goodness and truth and beauty of life, have their roots in this apparently barren soil. This is the true knowledge. We had founded our idealism on the most nihilistic implications of science, our socialism on crass self-interest, our peace on our capacity for mutual destruction, and our liberty on determinism. We had replaced morality with convention, bravery with safety, frugality with plenty, philosophy with science, stoicism with anaesthetics and piety with immortality. The universal acid of the true knowledge had burned away a world of words, and exposed a universe of things. Things we could use.
This is certainly something that some people will believe, particularly cynical college students who love political theory, feeling smarter than other people, and calling their pet theories things like "the true knowledge." It is not even remotely believable as the governing philosophy of a solar confederation. The point of government for the average person in human society is to create and enforce predictable mutual rules that one can use as a basis for planning and habits, allowing you to not think about politics all the time. People who adore thinking about politics have great difficulty understanding how important it is to everyone else to have ignorable government. Constantly testing your power against other coalitions is a sport, not a governing philosophy. Given the implication that this testing is through violence or the threat of violence, it beggars belief that any large number of people would tolerate that type of instability for an extended period of time. Ellen is fully committed to the true knowledge. MacLeod likely is not; I don't think this represents the philosophy of the author. But the primary political conflict in this novel famous for being political science fiction is between the above variation of anarchy and an anarchocapitalist society, neither of which are believable as stable political systems for large numbers of people. This is a bit like seeking out a series because you were told it was about a great clash of European monarchies and discovering it was about a fight between Liberland and Sealand. It becomes hard to take the rest of the book seriously. I do realize that one point of political science fiction is to play with strange political ideas, similar to how science fiction plays with often-implausible science ideas. But those ideas need some contact with human nature. If you're going to tell me that the key to clawing society back from a world-wide catastrophic descent into chaos is to discard literally every social system used to create predictability and order, you had better be describing aliens, because that's not how humans work. The rest of the book is better. I am untangling a lot of backstory for the above synopsis, which in the book comes in dribs and drabs, but piecing that together is good fun. The plot is far more straightforward than the previous two books in the series: there is a clear enemy, a clear goal, and Ellen goes from point A to point B in a comprehensible way with enough twists to keep it interesting. The core moral conflict of the book is that Ellen is an anti-AI fanatic to the point that she considers anyone other than non-uploaded humans to be an existential threat. MacLeod gives the reader both reasons to believe Ellen is right and reasons to believe she's wrong, which maintains an interesting moral tension. One thing that MacLeod is very good at is what Bob Shaw called "wee thinky bits." I think my favorite in this book is the computer technology used by the Cassini Division, who have spent a century in close combat with inimical AI capable of infecting any digital computer system with tailored viruses. As a result, their computers are mechanical non-Von-Neumann machines, but mechanical with all the technology of a highly-advanced 24th century civilization with nanometer-scale manufacturing technology. It's a great mental image and a lot of fun to think about. This is the only science fiction novel that I can think of that has a hard-takeoff singularity that nonetheless is successfully resisted and fought to a stand-still by unmodified humanity. Most writers who were interested in the singularity idea treated it as either a near-total transformation leaving only remnants or as something that had to be stopped before it started. MacLeod realizes that there's no reason to believe a post-singularity form of life would be either uniform in intent or free from its own baffling sudden collapses and reversals, which can be exploited by humans. It makes for a much better story. The sociology of this book is difficult to swallow, but the characterization is significantly better than the previous books of the series and the plot is much tighter. I was too annoyed by the political science to fully enjoy it, but that may be partly the fault of my expectations coming in. If you like chewy, idea-filled science fiction with a lot of unexplained world-building that you have to puzzle out as you go, you may enjoy this, although unfortunately I think you need to read at least The Stone Canal first. The ending was a bit unsatisfying, but even that includes some neat science fiction ideas. Followed by The Sky Road, although I understand it is not a straightforward sequel. Rating: 6 out of 10

11 October 2023

Russell Coker: The PineTime

I have just got a PineTime smart watch [1] from Pine64. They cost $US27 each which ended up as $144.63 Australian for three including postage when I ordered on the 16th of September, it s annoying that you can t order more than 3 at a time to reduce postage costs. The Australian online store Kogan has smart watches starting at about $15 [2] with Bluetooth and support for phone notifications so the $48.21 for a PineTime doesn t compare well on just price and features. The watches Kogan sells start getting into high resolution at around the $25 price and many of them have features like 24*7 heart monitoring that the PineTime lacks (it just measures when you request it). No-one would order a PineTime for being cheap or having lots of features, you order it because you want open hardware that allows you to do things your way. Also the PineTime isn t going to be orphaned while it s likely that in a few years most of the cheap watches sold by Kogan etc won t support the new phones running the latest version of Android. The screen of the PineTime is 240*240 resolution (about 260dpi) with 64k colors. The screen resolution is lower than some high-end smart watches but higher than most phones and almost all monitors. I doubt that much benefit could be gained from higher resolution. Even on minimum brightness the screen is easy to read on all but the brightest sunny days. The compute capabilities are 4.5MB of flash storage, 64k of RAM, and a 64MHz CPU this can t run Linux and nothing like it will run Linux for a long time. I ve had the PineTime for 6 days now, I charged it once and it s now at 55% battery. It looks like it will last close to 2 weeks on a single charge and it s claimed that a newer firmware will make the battery last longer. Software The main Android app for using with the PineTime is GadgetBridge which I installed from the f-droid repository. It had lots of click-through menus for allowing access to various Android features (contacts, bluetooth, draw over foreground, location, and more) but after that it was easy to setup. It was the first bluetooth device I ve used which had a 6 digit PIN for connecting to a phone. Initially I used the PineTime with my Huawei Nova 7i [3]. The aim is to eventually have it run from my PinePhonePro but my test of the PinePhonePro didn t go as well as hoped [4]. Now I m using it on my Huawei Mate 10 Pro. It comes with InfiniTime [5] installed as the default firmware, mine had 1.11.0 which is a fairly recent version. I will probably upgrade it soon to get the better power optimisation and weather alerts in the watch face. I don t have any plans to use different watch firmware and I don t have any plans to contribute to firmware development I just can t hack on every FOSS project around it s better to do big contributions to a small number of projects. For people who don t want the default firmware the Wasp-OS project seems interesting as it s written in Python [6], I don t like Python but it s very popular. Python is particularly popular in ML development, it will be interesting to see if Wasp-OS becomes a preferred platform for smart watches that talk to GPT servers. Generally the software works well, one annoyance is that when a notification goes away on the phone it remains on the PineTime and has to be manually dismissed. It would be nice if clearing notifications on the phone would clear them on the PineTime too. The music control works with RocketPlayer on Android, it displays the track name and has options for pause/play and skipping forward and backward one track. Annoyingly the current firmware doesn t allow configuring the main screens, from the primary screen you swipe down for notifications, right for settings, up for menus, and there s nothing defined for swipe left. I d like to make swipe left the command to get to music control. Hardware It has a detachable band that appears to be within the common range of watch bands. According to the PineTime Wiki page [7] there are a selection of alternate bands that will fit it, but some don t because the band is recessed into the watch. It is IP67 rated which means you can probably wear it while swimming. The charging contacts are exposed on the bottom of the case which means that any chemicals left by pool water can be cleaned off and also as they are apparently not expected to be harmed by sweat and skin oil there shouldn t be a problem charging it. I have significant experience using a Samsung Galaxy S5 Mini which is rated at IP67 in swimming pools. I had two problems with the S5 Mini when getting out of the pool, firstly water in the headphone socket made the phone consider that it was in headphone mode and turn off the speakers and secondly it took hours to become dry enough to charge and after many swims the charge rate dropped presumably due to oxide on the contacts. There are reports of success when swimming with a PineTime. Generally it feels well made and appears more solid than the cheapest Kogan devices appear to be. Conclusion If I wanted monitoring for medical reasons then I would choose a different smart watch. I ve read about people doing things like tracking their body stats 24*7 and trying to discover useful things, the PineTime is not a good option for BioHacking type use. However if I did have a need for such things I d probably just buy a second smart watch and have one on each wrist. The PineTime generally works well. It s a pity it has fewer hardware features than closed devices that are cheaper. But having a firmware that can be continually improved by the community is good. The continually expanding use of mobile phone technology devices for custom use in corporations (such as mobile phone in custom case for scanning prices etc in a supermarket) has some potential for use with this. I can imagine someone adding some custom features to a PineTime for such use. When a supermarket chain has 200,000 employees (as Woolworths in Australia does) then paying for a few months of software development work to make a smart watch do specific things for that company could provide significant value. There are probably some business opportunities for FOSS developers to hack on extra hardware on a PineTime and write software to support it. I recommend that everyone who s into FOSS buy one of these. Preferably make a deal with two friends to get the minimum postage cost.

3 October 2023

Junichi Uekawa: Electronic receipt storage in Japan.

Electronic receipt storage in Japan. Japan also started allowing electronic data for receipts, but had some red tape associated with it. Presumably they were worried about increase in fraud cases. Law amendment that went in effet Jan 2022 made the last annoying bits simpler. We used to be required to sign the paper receipt and scan within 3 days of receiving the receipt. This special requirement is now gone. It took a few years to reach this state but now we are at a similar state as our colleagues in the US. Nice.

19 September 2023

Valhalla's Things: Installing minidlna

Posted on September 19, 2023
I ve found the draft of this article I almost completely wrote (checks) more than 3 months ago, and I guess it s time to finish and publish it. The very first A10 based device that entered our home, before they started to use it for SBCs, was a Chinese media server with a slot for a 3.5" hard disk and a few analogue audio outputs. Of course from the time it entered our home it has always been running Debian. Now that we may have a few, more powerful, A20 SBCs available, it has been fully dedicated to music: it is connected to the stereo, the hard disk has a clone of the git-annex repository where I ve ripped all of my CDs1 and is played by connecting via ssh and running alsaplayer. It s simple (for my tastes). it works. Unless you re in a different room than the one with the stereo. And then I read this post on the fediverse that suggested installing minidlna on an old Raspberry Pi, and on a whim I decided I needed it. I installed the package from Debian, set a few easy settings in the configuration file (such as which directories to serve), restarted the service. And that s it, it just worked. The only thing I had to take care about is that to use git-annex repositories as the source of media files either the root of the repository should be used as media-dir, or the wide_links options should be set to yes, otherwise the symbolic links that point outside of the media-dir won t be served. As a client I used VLC (note for myself in case I ever forget, it s under View Playlist and then Local Network Universal Plug n Play), mostly because I already had it around. Now that I ve used it for a few months I have to say that it isn t a perfect solution: the main format I store my music in is in flac 2, which isn t supported by dlna; for a significant part of it I ve also already generated single-song ogg files for convenience 3, and at least it works for those. I don t store (yet?) my video collection on the A10 device, but I did a quick test, and no, of course a raw dump of a DVD as generated by dvdbackup isn t supported, so I would have to convert those too. And there is some support for subtitles as a separate file (which is something else I tend to have around), but only one file, with strict requirements for the name, which is a bit restrictive. On the other hand, the hassle to set this up was so low that the functionality / hassle ratio is most definitely worth, and I m quite happy I did and plan to continue using it.

  1. (yes, I m still using CDs, I have objections to those newfangled streaming services)
  2. full CD rip in a single file, with an embedded cuesheet, to preserve as much as possible of the original disc.
  3. in theory the flac was supposed to be future-proof storage, with the ogg files for actual use, but then I always listen to full albums, so the flac just work, and I only tend to bother generating the ogg when I m already generating mp3 for the car.

12 September 2023

Jo Shields: Building a NAS

The status quo Back in 2015, I bought an off-the-shelf NAS, a QNAP TS-453mini, to act as my file store and Plex server. I had previously owned a Synology box, and whilst I liked the Synology OS and experience, the hardware was underwhelming. I loaded up the successor QNAP with four 5TB drives in RAID10, and moved all my files over (after some initial DoA drive issues were handled).
QNAP TS-453mini product photoQNAP TS-453mini product photo
That thing has been in service for about 8 years now, and it s been a mixed bag. It was definitely more powerful than the predecessor system, but it was clear that QNAP s OS was not up to the same standard as Synology s perhaps best exemplified by HappyGet 2 , the QNAP webapp for downloading videos from streaming services like YouTube, whose icon is a straight rip-off of StarCraft 2. On its own, meaningless but a bad omen for overall software quality
The logo for QNAP HappyGet 2 and Blizzard's Starcraft 2 side by sideThe logo for QNAP HappyGet 2 and Blizzard s StarCraft 2 side by side
Additionally, the embedded Celeron processor in the NAS turned out to be an issue for some cases. It turns out, when playing back videos with subtitles, most Plex clients do not support subtitles properly instead they rely on the Plex server doing JIT transcoding to bake the subtitles directly into the video stream. I discovered this with some Blu-Ray rips of Game of Thrones some episodes would play back fine on my smart TV, but episodes with subtitled Dothraki speech would play at only 2 or 3 frames per second. The final straw was a ransomware attack, which went through all my data and locked every file below a 60MiB threshold. Practically all my music gone. A substantial collection of downloaded files, all gone. Some of these files had been carried around since my college days digital rarities, or at least digital detritus I felt a real sense of loss at having to replace. This episode was caused by a ransomware targeting specific vulnerabilities in the QNAP OS, not an error on my part. So, I decided to start planning a replacement with:
  • A non-garbage OS, whilst still being a NAS-appliance type offering (not an off-the-shelf Linux server distro)
  • Full remote management capabilities
  • A small form factor comparable to off-the-shelf NAS
  • A powerful modern CPU capable of transcoding high resolution video
  • All flash storage, no spinning rust
At the time, no consumer NAS offered everything (The Asustor FS6712X exists now, but didn t when this project started), so I opted to go for a full DIY rather than an appliance not the first time I ve jumped between appliances and DIY for home storage.

Selecting the core of the system There aren t many companies which will sell you a small motherboard with IPMI. Supermicro is a bust, so is Tyan. But ASRock Rack, the server division of third-tier motherboard vendor ASRock, delivers. Most of their boards aren t actually compliant Mini-ITX size, they re a proprietary Deep Mini-ITX with the regular screw holes, but 40mm of extra length (and a commensurately small list of compatible cases). But, thankfully, they do have a tiny selection of boards without the extra size, and I stumbled onto the X570D4I-2T, a board with an AMD AM4 socket and the mature X570 chipset. This board can use any AMD Ryzen chip (before the latest-gen Ryzen 7000 series); has built in dual 10 gigabit ethernet; IPMI; four (laptop-sized) RAM slots with full ECC support; one M.2 slot for NVMe SSD storage; a PCIe 16x slot (generally for graphics cards, but we live in a world of possibilities); and up to 8 SATA drives OR a couple more NVMe SSDs. It s astonishingly well featured, just a shame it costs about $450 compared to a good consumer-grade Mini ITX AM4 board costing less than half that. I was so impressed with the offering, in fact, that I crowed about it on Mastodon and ended up securing ASRock another sale, with someone else looking into a very similar project to mine around the same timespan. The next question was the CPU. An important feature of a system expected to run 24/7 is low power, and AM4 chips can consume as much as 130W under load, out of the box. At the other end, some models can require as little as 35W under load the OEM-only GE suffix chips, which are readily found for import on eBay. In their PRO variant, they also support ECC (all non-G Ryzen chips support ECC, but only Pro G chips do). The top of the range 8 core Ryzen 7 PRO 5750GE is prohibitively expensive, but the slightly weaker 6 core Ryzen 5 PRO 5650GE was affordable, and one arrived quickly from Hong Kong. Supplemented with a couple of cheap 16 GiB SODIMM sticks of DDR4 PC-3200 direct from Micron for under $50 a piece, that left only cooling as an unsolved problem to get a bootable test system. The official support list for the X570D4I-2T only includes two rackmount coolers, both expensive and hard to source. The reason for such a small list is the non standard cooling layout of the board instead of an AM4 hole pattern with the standard plastic AM4 retaining clips, it has an Intel 115x hole pattern with a non-standard backplate (Intel 115x boards have no backplate, the stock Intel 115x cooler attaches to the holes with push pins). As such every single cooler compatibility list excludes this motherboard. However, the backplate is only secured with a mild glue with minimal pressure and a plastic prying tool it can be removed, giving compatibility with any 115x cooler (which is basically any CPU cooler for more than a decade). I picked an oversized low profile Thermalright AXP120-X67 hoping that its 120mm fan would cool the nearby MOSFETs and X570 chipset too.
Thermalright AXP120-X67, AMD Ryzen 5 PRO 5650GE, ASRock Rack X570D4I-2T, all assembled and running on a flat surface

Testing up to this point Using a spare ATX power supply, I had enough of a system built to explore the IPMI and UEFI instances, and run MemTest86 to validate my progress. The memory test ran without a hitch and confirmed the ECC was working, although it also showed that the memory was only running at 2933 MT/s instead of the rated 3200 MT/s (a limit imposed by the motherboard, as higher speeds are considered overclocking). The IPMI interface isn t the best I ve ever used by a long shot, but it s minimum viable and allowed me to configure the basics and boot from media entirely via a Web browser.
Memtest86 showing test progress, taken from IPMI remote control window
One sad discovery, however, which I ve never seen documented before, on PCIe bifurcation. With PCI Express, you have a number of lanes which are allocated in groups by the motherboard and CPU manufacturer. For Ryzen prior to Ryzen 7000, that s 16 lanes in one slot for the graphics card; 4 lanes in one M.2 connector for an SSD; then 4 lanes connecting the CPU to the chipset, which can offer whatever it likes for peripherals or extra lanes (bottlenecked by that shared 4x link to the CPU, if it comes down to it). It s possible, with motherboard and CPU support, to split PCIe groups up for example an 8x slot could be split into two 4x slots (eg allowing two NVMe drives in an adapter card NVME drives these days all use 4x). However with a Cezanne Ryzen with integrated graphics, the 16x graphics card slot cannot be split into four 4x slots (ie used for for NVMe drives) the most bifurcation it allows is 8x4x4x, which is useless in a NAS.
Screenshot of PCIe 16x slot bifurcation options in UEFI settings, taken from IPMI remote control window
As such, I had to abandon any ideas of an all-NVMe NAS I was considering: the 16x slot split into four 4x, combined with two 4x connectors fed by the X570 chipset, to a total of 6 NVMe drives. 7.6TB U.2 enterprise disks are remarkably affordable (cheaper than consumer SATA 8TB drives), but alas, I was locked out by my 5650GE. Thankfully I found out before spending hundreds on a U.2 hot swap bay. The NVMe setup would be nearly 10x as fast as SATA SSDs, but at least the SATA SSD route would still outperform any spinning rust choice on the market (including the fastest 10K RPM SAS drives)

Containing the core The next step was to pick a case and power supply. A lot of NAS cases require an SFX (rather than ATX) size supply, so I ordered a modular SX500 unit from Silverstone. Even if I ended up with a case requiring ATX, it s easy to turn an SFX power supply into ATX, and the worst result is you have less space taken up in your case, hardly the worst problem to have. That said, on to picking a case. There s only one brand with any cachet making ITX NAS cases, Silverstone. They have three choices in an appropriate size: CS01-HS, CS280, and DS380. The problem is, these cases are all badly designed garbage. Take the CS280 as an example, the case with the most space for a CPU cooler. Here s how close together the hotswap bay (right) and power supply (left) are:
Internal image of Silverstone CS280 NAS build. Image stolen from ServeTheHome
With actual cables connected, the cable clearance problem is even worse:
Internal image of Silverstone CS280 NAS build. Image stolen from ServeTheHome
Remember, this is the best of the three cases for internal layout, the one with the least restriction on CPU cooler height. And it s garbage! Total hot garbage! I decided therefore to completely skip the NAS case market, and instead purchase a 5.25 -to-2.5 hot swap bay adapter from Icy Dock, and put it in an ITX gamer case with a 5.25 bay. This is no longer a served market 5.25 bays are extinct since nobody uses CD/DVD drives anymore. The ones on the market are really new old stock from 2014-2017: The Fractal Design Core 500, Cooler Master Elite 130, and Silverstone SUGO 14. Of the three, the Fractal is the best rated so I opted to get that one however it seems the global supply of new old stock fully dried up in the two weeks between me making a decision and placing an order leaving only the Silverstone case. Icy Dock have a selection of 8-bay 2.5 SATA 5.25 hot swap chassis choices in their ToughArmor MB998 series. I opted for the ToughArmor MB998IP-B, to reduce cable clutter it requires only two SFF-8611-to-SF-8643 cables from the motherboard to serve all eight bays, which should make airflow less of a mess. The X570D4I-2T doesn t have any SATA ports on board, instead it has two SFF-8611 OCuLink ports, each supporting 4 PCI Express lanes OR 4 SATA connectors via a breakout cable. I had hoped to get the ToughArmor MB118VP-B and run six U.2 drives, but as I said, the PCIe bifurcation issue with Ryzen G chips meant I wouldn t be able to run all six bays successfully.
NAS build in Silverstone SUGO 14, mid build, panels removed
Silverstone SUGO 14 from the front, with hot swap bay installed

Actual storage for the storage server My concept for the system always involved a fast boot/cache drive in the motherboard s M.2 slot, non-redundant (just backups of the config if the worst were to happen) and separate storage drives somewhere between 3.8 and 8 TB each (somewhere from $200-$350). As a boot drive, I selected the Intel Optane SSD P1600X 58G, available for under $35 and rated for 228 years between failures (or 11,000 complete drive rewrite cycles). So, on to the big expensive choice: storage drives. I narrowed it down to two contenders: new-old-stock Intel D3-S4510 3.84TB enterprise drives, at about $200, or Samsung 870 QVO 8TB consumer drives, at about $375. I did spend a long time agonizing over the specification differences, the ZFS usage reports, the expected lifetime endurance figures, but in reality, it came down to price $1600 of expensive drives vs $3200 of even more expensive drives. That s 27TB of usable capacity in RAID-Z1, or 23TB in RAID-Z2. For comparison, I m using about 5TB of the old NAS, so that s a LOT of overhead for expansion.
Storage SSD loaded into hot swap sled

Booting up Bringing it all together is the OS. I wanted an appliance NAS OS rather than self-administering a Linux distribution, and after looking into the surrounding ecosystems, decided on TrueNAS Scale (the beta of the 2023 release, based on Debian 12).
TrueNAS Dashboard screenshot in browser window
I set up RAID-Z1, and with zero tuning (other than enabling auto-TRIM), got the following performance numbers:
IOPSBandwidth
4k random writes19.3k75.6 MiB/s
4k random reads36.1k141 MiB/s
Sequential writes 2300 MiB/s
Sequential reads 3800 MiB/s
Results using fio parameters suggested by Huawei
And for comparison, the maximum theoretical numbers quoted by Intel for a single drive:
IOPSBandwidth
4k random writes16k?
4k random reads90k?
Sequential writes 280 MiB/s
Sequential reads 560 MiB/s
Numbers quoted by Intel SSD successors Solidigm.
Finally, the numbers reported on the old NAS with four 7200 RPM hard disks in RAID 10:
IOPSBandwidth
4k random writes4301.7 MiB/s
4k random reads800632 MiB/s
Sequential writes 311 MiB/s
Sequential reads 566 MiB/s
Performance seems pretty OK. There s always going to be an overhead to RAID. I ll settle for the 45x improvement on random writes vs. its predecessor, and 4.5x improvement on random reads. The sequential write numbers are gonna be impacted by the size of the ZFS cache (50% of RAM, so 16 GiB), but the rest should be a reasonable indication of true performance. It took me a little while to fully understand the TrueNAS permissions model, but I finally got Plex configured to access data from the same place as my SMB shares, which have anonymous read-only access or authenticated write access for myself and my wife, working fine via both Linux and Windows. And that s it! I built a NAS. I intend to add some fans and more RAM, but that s the build. Total spent: about $3000, which sounds like an unreasonable amount, but it s actually less than a comparable Synology DiskStation DS1823xs+ which has 4 cores instead of 6, first-generation AMD Zen instead of Zen 3, 8 GiB RAM instead of 32 GiB, no hardware-accelerated video transcoding, etc. And it would have been a whole lot less fun!
The final system, powered up
(Also posted on PCPartPicker)

11 September 2023

John Goerzen: For the First Time In Years, I m Excited By My Computer Purchase

Some decades back, when I d buy a new PC, it would unlock new capabilities. Maybe AGP video, or a PCMCIA slot, or, heck, sound. Nowadays, mostly new hardware means things get a bit faster or less crashy, or I have some more space for files. It s good and useful, but sorta meh. Not this purchase. Cory Doctorow wrote about the Framework laptop in 2021:
There s no tape. There s no glue. Every part has a QR code that you can shoot with your phone to go to a service manual that has simple-to-follow instructions for installing, removing and replacing it. Every part is labeled in English, too! The screen is replaceable. The keyboard is replaceable. The touchpad is replaceable. Removing the battery and replacing it takes less than five minutes. The computer actually ships with a screwdriver.
Framework had been on my radar for awhile. But for various reasons, when I was ready to purchase, I didn t; either the waitlist was long, or they didn t have the specs I wanted. Lately my aging laptop with 8GB RAM started OOMing (running out of RAM). My desktop had developed a tendency to hard hang about once a month, and I researched replacing it, but the cost was too high to justify. But when I looked into the Framework, I thought: this thing could replace both. It is a real shift in perspective to have a laptop that is nearly as upgradable as a desktop, and can be specced out to exactly what I wanted: 2TB storage and 64GB RAM. And still cheaper than a Macbook or Thinkpad with far lower specs, because the Framework uses off-the-shelf components as much as possible. Cory Doctorow wrote, in The Framework is the most exciting laptop I ve ever broken:
The Framework works beautifully, but it fails even better Framework has designed a small, powerful, lightweight machine it works well. But they ve also designed a computer that, when you drop it, you can fix yourself. That attention to graceful failure saved my ass.
I like small laptops, so I ordered the Framework 13. I loaded it up with the 64GB RAM and 2TB SSD I wanted. Frameworks have four configurable ports, which are also hot-swappable. I ordered two USB-C, one USB-A, and one HDMI. I put them in my preferred spots (one USB-C on each side for easy docking and charging). I put Debian on it, and it all Just Worked. Perfectly. Now, I orderd the DIY version. I hesitated about this I HATE working with laptops because they re all so hard, even though I KNEW this one was different but went for it, because my preferred specs weren t available in a pre-assembled model. I m glad I did that, because assembly was actually FUN. I got my box. I opened it. There was the bottom shell with the motherboard and CPU installed. Here are the RAM sticks. There s the SSD. A minute or two with each has them installed. Put the bezel on the screen, attach the keyboard it has magnets to guide it into place and boom, ready to go. Less than 30 minutes to assemble a laptop nearly from scratch. It was easier than assembling most desktops. So now, for the first time, my main computing device is a laptop. Rather than having a desktop and a laptop, I just have a laptop. I ll be able to upgrade parts of it later if I want to. I can rearrange the ports. And I can take all my most important files with me. I m quite pleased!

29 August 2023

Jonathan Dowland: Gazelle Twin

A couple of releases A couple of releases
I discovered Gazelle Twin last year via Stuart Maconie's Freak Zone (two of her tracks ended up on my 2022 Halloween playlist). Through her website I learned of The Horror Show! exhibition at Somerset House1 in London that I managed to visit earlier this year. I've been intending to write a 5-track blog post (a la Underworld, the Cure, Coil) for a while but I have been spurred on by the excellent news that she's got a new album on the way, and, she's performing at the Sage Gateshead in November. Buy tickets now!! Here's the five tracks I recommend to get started:
  1. Anti-Body, from 2014's UNFLESH. I particularly love the percussion. Perc did a good hard-house-style remix on Fleshed Out, the companion remix album. Anti-Body by Gazelle Twin
  2. Fire Leap, from Gazelle Twin and NYX's collaborative album Deep England. The album is a re-interpretation of material from Gazelle Twin's earlier album, Pastoral, with the exception of this track, which is a cover of Paul Giovanni's song from The Wicker Man. There's a common aesthetic in all three works: eerie-folk, England's self-mythologising as seen through a warped and cracked lens. Anti-Body by Gazelle Twin There's a fantastic performance video of the whole album, directed by Iain Forsyth and Jane Pollard, available on YouTube.
  3. Better In My Day, from the aforementioned Pastoral. This track and this album are, I think, less accessible, more challenging than the re-interpreted material. That's not a bad thing: I'm still working on digesting it! This is one of the more abrasive, confrontational tracks. Better In My Day by Gazelle Twin
  4. I am Shell I am Bone, from way back to her first release, The Entire City in 2011. Composed, recorded, self-produced, self-released. It's remarkable to me how different each phase of GT's work are to one another. This album evokes a strong sense of atmosphere and place to me. There's a hint of possible influence of Joy Division's Unknown Pleasures (or New Order's Movement) in places. The b-side to this song is a cover of Joy Division's The Eternal. I Am Shell I Am Bone by Gazelle Twin
  5. GT re-issued This Entire City in 2022 along with a companion-piece EP of newly-released material from the same era, The Wastelands. This isn't cutting room floor stuff, though, as evidenced by the strength of my final pick, Hole in my Heart. Hole In My Heart by Gazelle Twin
It's hard to pick just five tracks when doing these (that's the point I suppose). I note that I haven't picked anything from her wide-ranging soundtrack work: her last three or four of her releases have been soundtrack works, released on the well-respected UK label Invada, as will be her forthcoming album. You can find all the released stuff on Gazelle Twin's Bandcamp Page.

  1. I recently learned that PJ Harvey once hosted album sessions in Somerset House, and allowed fans to watch her at work during the recording: https://www.theguardian.com/music/2015/jan/16/pj-harvey-somerset-house-recording-in-progress

9 August 2023

Antoine Beaupr : OpenPGP key transition

This is a short announcement to say that I have changed my main OpenPGP key. A signed statement is available with the cryptographic details but, in short, the reason is that I stopped using my old YubiKey NEO that I have worn on my keyring since 2015. I now have a YubiKey 5 which supports ED25519 which features much shorter keys and faster decryption. It allowed me to move all my secret subkeys on the key (including encryption keys) while retaining reasonable performance. I have written extensive documentation on how to do that OpenPGP key rotation and also YubiKey OpenPGP operations.

Warning on storing encryption keys on a YubiKey People wishing to move their private encryption keys to such a security token should be very careful as there are special precautions to take for disaster recovery. I am toying with the idea of writing an article specifically about disaster recovery for secrets and backups, dealing specifically with cases of death or disabilities.

Autocrypt changes One nice change is the impact on Autocrypt headers, which are considerably shorter. Before, the header didn't even fit on a single line in an email, it overflowed to five lines:
Autocrypt: addr=anarcat@torproject.org; prefer-encrypt=nopreference;
 keydata=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
After the change, the entire key fits on a single line, neat!
Autocrypt: addr=anarcat@torproject.org; prefer-encrypt=nopreference;
 keydata=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
Note that I have implemented my own kind of ridiculous Autocrypt support for the Notmuch Emacs email client I use, see this elisp code. To import keys, I pipe the message into this script which is basically just:
sq autocrypt decode   gpg --import
... thanks to Sequoia best-of-class Autocrypt support.

Note on OpenPGP usage While some have claimed OpenPGP's death, I believe those are overstated. Maybe it's just me, but I still use OpenPGP for my password management, to authenticate users and messages, and it's the interface to my YubiKey for authenticating with SSH servers. I understand people feel that OpenPGP is possibly insecure, counter-intuitive and full of problems, but I think most of those problems should instead be attributed to its current flagship implementation, GnuPG. I have tried to work with GnuPG for years, and it keeps surprising me with evilness and oddities. I have high hopes that the Sequoia project can bring some sanity into this space, and I also hope that RFC4880bis can eventually get somewhere so we have a more solid specification with more robust crypto. It's kind of a shame that this has dragged on for so long, but Update: there's a separate draft called openpgp-crypto-refresh that might actually be adopted as the "OpenPGP RFC" soon! And it doesn't keep real work from happening in Sequoia and other implementations. Thunderbird rewrote their OpenPGP implementation with RNP (which was, granted, a bumpy road because it lost compatibility with GnuPG) and Sequoia now has a certificate store with trust management (but still no secret storage), preliminary OpenPGP card support and even a basic GnuPG compatibility layer. I'm also curious to try out the OpenPGP CA capabilities. So maybe it's just because I'm becoming an old fart that doesn't want to change tools, but so far I haven't seen a good incentive in switching away from OpenPGP, and haven't found a good set of tools that completely replace it. Maybe OpenSSH's keys and CA can eventually replace it, but I suspect they will end up rebuilding most of OpenPGP anyway, just more slowly. If they do, let's hope they avoid the mistakes our community has done in the past at least...

27 July 2023

Louis-Philippe V ronneau: My new friend Ted

About 6 months ago, I decided to purchase a bike trailer. I don't drive and although I also have a shopping caddy, it often can't handle a week's groceries. The trailer, attached to my bike, hauling two storage crates Since the goal for the trailer was to haul encumbering and heavy loads, I decided to splurge and got a Surly Ted. The 32" x 24" flat bed is very versatile and the trailer is rated for up to 300 lbs (~135 kg). At around 30 lbs (~13.5 kg), the trailer itself is light enough for me to climb up the stairs to my apartment with it. Having seldom driven a bike trailer before, I was at first worried about its handling and if it would jerk me around (as some children's chariots tend to). I'm happy to report the two pronged hitch Surly designed works very well and lets you do 180 turns effortlessly. The trailer on my balcony, ready to be hoisted So far, I've used the trailer to go grocery shopping, buy bulk food and haul dirt and mulch. To make things easier, I've purchased two 45L storing crates from Home Depot and added two planks of wood on each side of the trailer to stabilise things when I strap the crates down to the bed. Since my partner and I are subscribed to an organic farmer's box during the summer and get baskets from Lufa during the winter, picking up our groceries at the pick-up point is as easy as dumping our order in the storing crates and strapping them back to the trailer. The pulleys on the roof of my balcony Although my housing cooperative has a (small) indoor bicycle parking space, my partner uses our spot during the summer, which means I have to store the trailer on my balcony. To make things more manageable and free up some space, I set up a system of pulleys to hoist the trailer up the air when it's not in use. I did go through a few iterations, but I'm pretty happy with the current 8 pulleys block and tackle mechanism I rigged. The trailer hoisted to the roof of the balcony All and all, this trailer wasn't cheap, but I regret nothing. Knowing Surley's reputation, it will last me many years and not having to drive a car to get around always ends up being the cheaper solution.

19 July 2023

Ian Jackson: Installing Debian bookworm without systemd

Instructions
  1. Get the official installation image from the usual locations. I got the netinst CD image via BitTorrent.
  2. Boot from the image and go through the installation in the normal way.
    1. You may want to select an alternative desktop environment (and unselect GNOME). These steps have been tested with MATE.
    2. Stop when you are asked to remove the installation media and reboot.
  3. Press Alt + Right arrow to switch to the text VC. Hit return to activate the console and run the following commands (answering yes as appropriate):
chroot /target bash
apt-get install sysvinit-core elogind ntp dbus-x11
apt-get autoremove
exit
  1. Observe the output from the apt-get install. If your disk arrangements are unusual, that may generate some error messages from update-initramfs.
  2. Go back to the installer VC with Alt + Left arrow. If there were no error messages above, you may tell it to reboot.
  3. If there were error messages (for example, I found that if there was disk encryption, alarming messages were printed), tell the installer to go Back . Then ask it to Install GRUB bootloader (again). After that has completed, you may reboot.
  4. Enjoy your Debian system without systemd.
Discussion This is pleasingly straightforward, albeit with an ugly wart. This recipe was not formally developed and tested; it s just what happened when I tried to actually perform this task. The official installation guide has similar instructions although they don t seem to have the initramfs workaround. update-initramfs The need to go back and have the installer reinstall grub is because if your storage is not very straightforward, the update-initramfs caused by apt-get install apparently doesn t have all the right context. I haven t investigated this at all; indeed, I don t even really know that the initramfs generated in step 3 above was broken, although the messages did suggest to me that important pieces or config might have been omitted. Instead, I simply chose to bet that it might be broken, but that the installer would know what to do. So I used the installer s install GRUB bootloader option, which does regenerate the initramfs. So, I don t know that step 6 is necessary. In principle it would be better to do the switch from systemd to sysvinit earlier in the installation process, and under the control of the installer. But by default the installer goes straight from the early setup questions through to the set the time or reboot questions, without stopping. One could use the expert mode, or modify the command line, or something, but all of those things are, in practice, a lot more typing and/or interaction. And as far as I m aware the installer doesn t have an option for avoiding systemd . The apt-get install line sysvinit-core is the principal part of the sysvinit init system. Asking to install that causes the deinstallation of systemd s init and ancillary packages. systemd refuses to allow itself to be deinstalled, if it is already running, so if you boot into the systemd system you can t then switch init system. This is why the switch is best done at install time. If you re too late, there are instructions for changing init system post-installation. elogind is a forked version of some of systemd s user desktop session functionality. In practice modern desktop environments need this; without it, apt will want to remove things you probably want to keep. Even if you force it, you may find that your desktop environment can t adjust the audio volume, etc. ntp is needed because nowadays the default network time client is systemd-timesyncd (which is a bad idea even on systems with systemd as init). We need to specify it because the package dependencies don t automatically give you any replacement for systemd-timesyncd. dbus-x11 is a glue component. In theory it ought to be installed automatically. However, there have been problems with the dependencies that meant that (for example) asking for emacs would try to switch the init system. Specifying dbus-x11 explicitly is a workaround for that, which I nowadays adopt out of caution. Perhaps it is no longer needed. (On existing systems, it may be necessary to manually install orphan-sysvinit-scripts, which exists as a suboptimal technical workaround for the sociopolitical problems of hostile package maintainers and Debian s governance failures. The recipe above seems to install this package automatically.) usrmerge This recipe results in a system which has merged-/usr via symlinks. This configuration is a bad one. Ideally usrmerge-via-symlinks would be avoided. The un-merged system is declared not officially supported by Debian and key packages try very hard to force it on users. However, merged-/usr-via-symlinks is full of bugs (mostly affecting package management) which are far too hard to fix (a project by some folks to try to do so has given up). I suspect un-merged systems will suffer from fewer bugs in practice. But I don t know how to persuade d-i to make one. Installer images I think there is room in the market for an unofficial installer image which installs without systemd and perhaps without usrmerge. I don t have the effort for making such a thing myself. Conclusion Installing Debian without systemd is fairly straightforward. Operating Debian without systemd is a pleasure and every time one of my friends has some systemd-induced lossage I get to feel smug.

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13 July 2023

Emmanuel Kasper: Debian 11 to Debian 12 (Bookworm) Upgrade Report

Laptop + Workstation My workstation was initially installed with Debian 8 back in the day, so I might have carried a lot of configuration cruft.
Indeed. I followed the recommended upgrades documentation (apt upgrade --without-new-pkgs followed by apt full-upgrade). And when executing apt full-upgrade I had the following error:
Preparing to unpack .../71-python3-numpy_1%3a1.24.2-1_amd64.deb ...
Unpacking python3-numpy (1:1.24.2-1) over (1:1.19.5-1) ...
dpkg: error processing archive /tmp/apt-dpkg-install-ibI85v/71-python3-numpy_1%3a1.24.2-1_amd64.deb (--unpack):
 trying to overwrite '/usr/bin/f2py', which is also in package python-numpy 1:1.16.5-5
Deleting the python-numpy package and resuming the upgrade with apt --fix-broken install followed by apt full-upgrade allowed the upgrade to complete successfully. This was already metioned in a Debian bug report and would have been avoided if I had purged the locally obsolete packages after upgrading to Debian 11. On laptop and workstation, after the upgrade, for unclear reasons, the gnome3 user extensions were disabled. I reenabled the extensions manually with
gsettings set org.gnome.shell disable-user-extensions false
Finally podman, had a major upgrade from 3 to 4, and a backward-incompatible configuration change. If a custom configuration file was in place in /etc/containers/storage.conf to override the default storage options, you need now to add the following stanza
[storage]
runroot="/run/containers/storage"
graphRoot="/var/lib/containers/storage"
in that file.
Otherwise you ll get the error Failed to obtain podman configuration: runroot must be set when running any podman command. This was discussed upstream. Cloud server (VM) Everything worked flawlessly, nothing to report. Conclusion Again a great Debian release, very happy that I could update three systems with ten thousands of packages with so little fuss. For my small home server running RHEL 8 (with the no cost sub) I will do a reinstall on newer hardware.

12 July 2023

John Goerzen: Backing Up and Archiving to Removable Media: dar vs. git-annex

This is the fourth in a series about archiving to removable media (optical discs such as BD-Rs and DVD+Rs or portable hard drives). Here are the first three parts: I want to state at the outset that this is not a general review of dar or git-annex. This is an analysis of how those tools stack up to a particular use case. Neither tool focuses on this use case, and I note it is particularly far from the more common uses of git-annex. For instance, both tools offer support for cloud storage providers and special support for ssh targets, but neither of those are in-scope for this post. Comparison Matrix As part of this project, I made a comparison matrix which includes not just dar and git-annex, but also backuppc, bacula/bareos, and borg. This may give you some good context, and also some reference for other projects in this general space. Reviewing the Goals I identified some goals in part 1. They are all valid. As I have thought through the project more, I feel like I should condense them into a simpler ordered list, with the first being the most important. I omit some things here that both dar and git-annex can do (updates/incrementals, for instance; see the expanded goals list in part 1). Here they are:
  1. The tool must not modify the source data in any way.
  2. It must be simple to create or update an archive. Processes that require a lot of manual work, are flaky, or are difficult to do correctly, are unlikely to be done correctly and often. If it s easy to do right, I m more likely to do it. Put another way: an archive never created can never be restored.
  3. The chances of a successful restore by someone that is not me, that doesn t know Linux, and is at least 10 years in the future, should be maximized. This implies a simple toolset, solid support for dealing with media errors or missing media, etc.
  4. Both a partial point-in-time restore and a full restore should be possible. The full restore must, at minimum, provide a consistent directory tree; that is, deletions, additions, and moves over time must be accurately reflected. Preserving modification times is a near-requirement, and preserving hard links, symbolic links, and other POSIX metadata is a significant nice-to-have.
  5. There must be a strategy to provide redundancy; for instance, a way for one set of archive discs to be offsite, another onsite, and the two to be periodically swapped.
  6. Use storage space efficiently.
Let s take a look at how the two stack up against these goals. Goal 1: Not modifying source data With dar, this is accomplished. dar --create does not modify source data (and even has a mode to avoid updating atime) so that s done. git-annex normally does modify source data, in that it typically replaces files with symlinks into its hash-indexed storage directory. It can instead use hardlinks. In either case, you will wind up with files that have identical content (but may have originally been separate, non-linked files) linked together with git-annex. This would cause me trouble, as well as run the risk of modifying timestamps. So instead of just storing my data under a git-annex repo as is its most common case, I use the directory special remote with importtree=yes to sort of import the data in. This, plus my desire to have the repos sensible and usable on non-POSIX operating systems, accounts for a chunk of the git-annex complexity you see here. You wouldn t normally see as much complexity with git-annex (though, as you will see, even without the directory special remote, dar still has less complexity). Winner: dar, though I demonstrated a working approach with git-annex as well. Goal 2: Simplicity of creating or updating an archive Let us simply start by recognizing this: Both tools have a lot of power, but I must say, it is easier to wrap my head around what dar is doing than what git-annex is doing. Everything dar does is with files: here are the files to archive, here is an archive file, here is a detached (isolated) catalog. It is very straightforward. It took me far less time to develop my dar page than my git-annex page, despite having existing familiarity with both tools. As I pointed out in part 2, I still don t fully understand how git-annex syncs metadata. Unsolved mysteries from that post include why the two git-annex drives had no idea what was on the other drives, and why the export operation silenty did nothing. Additionally, for the optical disc case, I had to create a restricted-size filesystem/dataset for git-annex to write into in order to get the desired size limit. Looking at the optical disc case, dar has a lot of nice infrastructure built in. With pause and execute, it can very easily be combined with disc burning operations. slice will automatically limit the size of a given slice, regardless of how much disk space is free, meaning that the git-annex tricks of creating smaller filesystems/datasets are unnecessary with dar. To create an initial full backup with dar, you just give it the size of the device, and it will automatically split up the archive, with hooks to integrate for burning or changing drives. About as easy as you could get. With git-annex, you would run the commands to have it fill up the initial filesystem, then burn the disc (or remove the drive), then run the commands to create another repo on the second filesystem, and so forth. With hard drives, with git-annex you would do something similar; let it fill up a repo on a drive, and if it exits with a space error, swap in the next. With dar, you would slice as with an optical disk. Dar s slicing is less convenient in this case, though, as it assumes every drive is the same size and yours may not be. You could work around that by using a slice size no bigger than the smallest drive, and putting multiple slices on larger drives if need be. If a single drive is large enough to hold your entire data set, though, you need not worry about this with either tool. Here s a warning about git-annex: it won t store anything beneath directories named .git. My use case doesn t have many of those. If your use case does, you re going to have to figure out what to do about it. Maybe rename them to something else while the backup runs? In any case, it is simply a fact that git-annex cannot back up git repositories, and this cuts against being able to back up things correctly. Another point is that git-annex has scalability concerns. If your archive set gets into the hundreds of thousands of files, you may need to split it into multiple distinct git-annex repositories. If this occurs and it will in my case it may serve to dull the shine of some of git-annex s features such as location tracking. A detour down the update strategies path Update strategies get a little more complicated with both. First, let s consider: what exactly should our update strategy be? For optical discs, I might consider doing a monthly update. I could burn a disc (or more than one, if needed) regardless of how much data is going to go onto it, because I want no more than a month s data lost in any case. An alternative might be to spool up data until I have a disc s worth, and then write that, but that could possibly mean months between actually burning a disc. Probably not good. For removable drives, we re unlikely to use a new drive each month. So there it makes sense to continue writing to the drive until it s full. Now we have a choice: do we write and preserve each month s updates, or do we eliminate intermediate changes and just keep the most recent data? With both tools, the monthly burn of an optical disc turns out to be very similar to the initial full backup to optical disc. The considerations for spanning multiple discs are the same. With both tools, we would presumably want to keep some metadata on the host so that we don t have to refer to a previous disc to know what was burned. In the dar case, that would be an isolated catalog. For git-annex, it would be a metadata-only repo. I illustrated both of these in parts 2 and 3. Now, for hard drives. Assuming we want to continue preserving each month s updates, with dar, we could just write an incremental to the drive each month. Assuming that the size of the incremental is likely far smaller than the size of the drive, you could easily enough do this. More fancily, you could look at the free space on the drive and tell dar to use that as the size of the first slice. For git-annex, you simply avoid calling drop/dropunused. This will cause the old versions of files to accumulate in .git/annex. You can get at them with git annex commands. This may imply some degree of elevated risk, as you are modifying metadata in the repo each month, which with dar you could chmod a-w or even chattr +i the archive files once written. Hopefully this elevated risk is low. If you don t want to preserve each month s updates, with dar, you could just write an incremental each month that is based on the previous drive s last backup, overwriting the previous. That implies some risk of drive failure during the time the overwrite is happening. Alternatively, you could write an incremental and then use dar to merge it into the previous incremental, creating a new one. This implies some degree of extra space needed (maybe on a different filesystem) while doing this. With git-annex, you would use drop/dropunused as I demonstrated in part 2. The winner for goal 2 is dar. The gap is biggest with optical discs and more narrow with hard drives, thanks to git-annex s different options for updates. Still, I would be more confident I got it right with dar. Goal 3: Greatest chance of successful restore in the distant future If you use git-annex like I suggested in part 2, you will have a set of discs or drives that contain a folder structure with plain files in them. These files can be opened without any additional tools at all. For sheer ability to get at raw data, git-annex has the edge. When you talk about getting a consistent full restore without multiple copies of renamed files or deleted files coming back then you are going to need to use git-annex to do that. Both git-annex and dar provide binaries. Dar provides a win64 version on its Sourceforge page. On the author s releases site, you can find the win64 version in addition to a statically-linked x86_64 version for Linux. The git-annex install page mostly directs you to package managers for your distribution, but the downloads page also lists builds for Linux, Windows, and Mac OS X. The Linux version is dynamic, but ships most of its .so files alongside. The Windows version requires cygwin.dll, and all versions require you to also install git itself. Both tools are in package managers for Mac OS X, Debian, FreeBSD, and so forth. Let s just say that you are likely to be able to run either one on a future Windows or Linux system. There are also GUI frontends for dar, such as DARGUI and gdar. This can increase the chances of a future person being able to use the software easily. git-annex has the assistant, which is based on a different use case and probably not directly helpful here. When it comes to doing the actual restore process using software, dar provides the easier process here. For dealing with media errors and the like, dar can integrate with par2. While technically you could use par2 against the files git-annex writes, that s more cumbersome to manage to the point that it is likely not to be done. Both tools can deal reasonably with missing media entirely. I m going to give the edge on this one to git-annex; while dar does provide the easier restore and superior tools for recovering from media errors, the ability to access raw data as plain files without any tools at all is quite compelling. I believe it is the most critical advantage git-annex has, and it s a big one. Goal 4: Support high-fidelity partial and full restores Both tools make it possible to do a full restore reflecting deletions, additions, and so forth. Dar, as noted, is easier for this, but it is possible with git-annex. So, both can achieve a consistent restore. Part of this goal deals with fidelity of the restore: preserving timestamps, hard and symbolic links, ownership, permissions, etc. Of these, timestamps are the most important for me. git-annex can t do any of that. dar does all of it. Some of this can be worked around using mtree as I documented in part 2. However, that implies a need to also provide mtree on the discs for future users, and I m not sure mtree really exists for Windows. It also cuts against the argument that git-annex discs can be used without any tools. It is true, they can, but all you will get is filename and content; no accurate date. Timestamps are often highly relevant for everything from photos to finding an elusive document or record. Winner: dar. Goal 5: Supporting backup strategies with redundancy My main goal here is to have two separate backup sets: one that is offsite, and one that is onsite. Depending on the strategy and media, they might just always stay that way, or periodically rotate. For instance, with optical discs, you might just burn two copies of every disc and store one at each place. For hard drives, since you will be updating the content of them, you might swap them periodically. This is possible with both tools. With both tools, if using the optical disc scheme I laid out, you can just burn two identical copies of each disc. With the hard drive case, with dar, you can keep two directories of isolated catalogs, one for each drive set. A little identifier file on each drive will let you know which set to use. git-annex can track locations itself. As I demonstrated in part 2, you can make each drive its own repo, add all drives from a given drive set to a git-annex group. When initializing a drive, you tell git-annex what group it s a prt of. From then on, git-annex knows what content is in each group and will add whatever a given drive s group needs to that drive. It s possible to do this with both, but the winner here is git-annex. Goal 6: Efficient use of storage Here are situations in which one or the other will be more efficient: The winner depends on your particular situation. Other notes While not part of the goals above, dar is capable of using tapes directly. While not as common, they are often used in communities of people that archive lots of data. Conclusions Overall, dar is the winner for me. It is simpler in most areas, easier to get correct, and scales very well. git-annex does, however, have some quite compelling points. Being able to access files as plain files is huge, and its location tracking is nicer than dar s, even when using dar_manager. Both tools are excellent and I recommend them both and for more than the particular scenario shown here. Both have fantastic and responsive authors.

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