Gordian Seed Tool

Gordian Seed Tool Cryptographic Seed Manager for iOS

by Wolf McNally and Christopher Allen

• part of the gordian technology family

Gordian Seed Tool protects your cryptographic seeds while also making them available for easy use. Using Seed Tool, you can generate seeds and store them securely on your device. You can then derive and share multi-signature signing and verification keys from those seeds. Sophisticated backup procedures include printed pages and Sharded Secret Key Reconstruction (SSKR) — which lets you split your seed into pieces and send them to trusted parties, who can send them back to you in an emergency for seed recovery. You can even use an entirely offline device (no internet access) to store your seeds and use QR codes to exchange necessary information with online devices running compatible wallet or signing software.

      

Demos (Videos)

• Seed Tool & SSKR

Installation Instructions

Gordian Seed Tool is available from the Apple Appstore for the iPhone, or can be compiled from source here.

To compile from source, simply choose "Code > Open with Xcode" from the top of the repo. This will download the code into Xcode, including all of the dependencies. After you will be able to Run (command-R) it for your Mac or a connected iOS device.

Usage Instructions

• Manual. An overview of installing and using Seed Tool, including info on adding seeds, storing seeds, using seeds, exporting seeds, and removing seeds.
• Integrating Seed Tool with Other Apps. Using Seed Tool as a real-life seedstore for live transactions coordinated by other apps.

Gordian Principles

Gordian Seed Tool is a reference implementation meant to display the Gordian Principles, which are philosophical and technical underpinnings to Blockchain Commons' Gordian technology. This includes:

• Independence. Seed Tool allows you to maintain personal control of your cryptographic key material.
• Privacy. Seed Tool ensures your privacy because everything is on your closely held mobile device.
• Resilience. Seed Tool uses 2FA by combining an Apple login with biometric authentication. It securely backs up your material to iCloud.
• Openness. Seed Tool communicates through airgaps via URs and QRs, for maximum interoperability.

Blockchain Commons apps do not phone home and do not run ads. Some are available through various app stores; all are available in our code repositories for your usage.

For related Threat Modeling, see the Seed Tool Manual.

Status - Released (1.6)

Gordian Seed Tool has been released through the Apple Appstore.

Version History

Join the Test Flight Open Beta

1.6.1 (79)

• THIS IS A RELEASE CANDIDATE
• Fixed: Some places in the app were still producing version 2 output descriptors. Version 2 output descriptors are still supported for reading but only Version 3 descriptors are now produced.

1.6 (78)

• THIS IS A RELEASE CANDIDATE
• Fixed: Seed backup URs were writing version 2 output descriptors. Now writing version 3.
• Fixed: Parsing seed backup URs only parsed version 2 output descriptors. Now parses version 2 or 3.

1.6 (77)

• THIS IS A RELEASE CANDIDATE
• Fixed: Output descriptor was not being included in the QR code on Seed backup printed pages.
• Improved layout of Seed Backup print page. Now makes more efficient use of page space and allows significantly longer notes to be printed without truncation.

1.6 (76)

• THIS IS A RELEASE CANDIDATE
• Seed Detail > Authenticate > Backup > Backup as Gordian Envelope > Print
  • The printed seed backup page "Derivations" section has been replaced with a display that varies depending on the "Primary Asset" app setting:
    • Bitcoin: The associated output descriptor (if any) is shown.
    • Ethereum: The ETH account ID is shown.
    • Tezos: The Tezos address is shown.
  • When any of the above are shown, a QR code containing the same information is also shown.
• Improved Bytewords and BIP-39 entry guidance messages.

1.6 (75)

• THIS IS A RELEASE CANDIDATE
• Fixed #186: Added word entry guidance.
  • When entering Bytewords or BIP-39 words to reconstruct a seed, guidance appears at the bottom of the field showing exactly which words are valid (green), invalid (red), or ambiguous (yellow).
  • Entering words is now more tolerant: as soon as a typed word is unambiguous, it is considered valid and this is reflected in the guidance. Bytewords can also be entered by just their first and last letters.
• Fixed #205: Write NFC doesn't work on a few very particular pages (request/response for keys). It just stalls and never does anything.
• Fixed #209: When pasting hex seeds from another device (using Continuity Clipboard) the first attempt would be discarded.
• Fixed #210: The code paths followed when a URL was injected from outside the app did not consider fountain code URs, causing strange behavior. When you scan an animated QR code from the Camera app, the "Open in Seed Tool" button will flicker each time a new QR code is shown. So I recommend just scanning one of them, then moving the camera off the animating codes, then tap the button. The app should open and start the scan session including the fountain code you just scanned. So just point the camera at the animating code again and continue.

1.6 (74)

• This version now requires iOS 17.0 or later.
• Account descriptor are now Version 2 in accordance with BCR-2023-019.
• Fixed #198. Now shows QR codes for signed PSBTs in same format as request.
• Fixed #203. HD Private Keys and HD Public Keys are no longer shown in the Key Export screen when Ethereum or Tezos is selected.
• Fixed #208. Now shows Tezos public and private keys on Seed Detail page.
• Fixed #201. Can now paste hex seeds that include spaces or other non hex-digit characters.
• Fixed #202. ur:output-descriptor can now be pasted into the OutputDescriptor field on the Seed Detail screen.
• Fixed #206. Backing up as SSKR shares says "Legacy ur:crypto-sskr" when it should say "Legacy ur:sskr".

1.6 (73)

• Tezos: Deriving Tezos keys and addresses is now supported.
  • The Settings view now allows Tezos to be selected as the Primary Asset
  • "Seed Detail > Authenticate > Derive Key > Other Key Derivations" now lets you select Tezos.
  • Tezos keys and addresses do not change for main or test nets, so you will not see indicators for network when working with Tezos.
  • To create a wallet with a private key, scroll down to the "Private Key" block and export the key, which for Tezos will begin with spsk. Paste this key into your Tezos wallet. For example, with the Umami wallet, you select "Add Account > I already have a wallet > Import with Secret Key" and paste the spsk string into the field.
  • Tezos accounts created with SeedTool will have addresses that begin with tz2. You can see the address at the bottom of the "Other Key Derivations" view, and it should match the address derived from your secret key in your Tezos wallet.
• Printing a seed: the Envelope will elide the seed name if it's longer than 100 characters and will elide the notes if they're longer than 500 characters.
• Fixed: SeedTool stopped reading ur:crypto-psbt (v1) and would only read ur:psbt (v2).
• Fixed: Some legacy ur:crypto-seed had dates tagged with 100 which is valid but we moved to the more comprehensive tag 1. We now support reading both tags for dates, so this is fixed.
• Now accepts four different formats for signing PSBTs:
  • Base64
  • Version 1 UR (ur:crypto-psbt)
  • Version 2 UR (ur:psbt)
  • Envelope (ur:envelope)
• When returning the results of a PSBT signing request, SeedTool always offers Envelope and binary (.psbt file). If the request was formatted as Version 1 UR, Version 2 UR, or Base64, the same format will be offered to return the result.
• The test vectors in Testing/PSBT Signing Request/* have been updated to reflect the above.

1.6 (72)

• SeedTool now exports the version 3 ur:output-descriptor (#6.40308) type, as documented in BCR-2023-010.
• SeedTool now exports version 2 CBOR tags for several structures, while maintaining backwards-compatibility with version 1 CBOR tags. So instead of exporting ur:crypto-seed (#6.300), SeedTool now exports ur:seed (#6.40300), while still being able to import ur:crypto-seed. This also applies to ur:crypto-sskr (#6.303) which is now ur:sskr (#6.40303) and ur:crypto-hdkey (#6.303) which is now ur:hdkey (#6.40303).

1.6 (71)

• The bottom of the Seed Detail screen has a new feature that lets a seed be associated with a primary output descriptor. The output descriptor may be pasted in its textual form or as a Gordian Envelope containing an output descriptor per BCR-2023-007
• The associated output descriptor is persisted with the seed and exported with the seed's Gordian Envelope.
• The associated output descriptor must be derived from the seed to which it is associated. Attempting to assocate an otherwise valid output descriptor not derived from the seed presents a specific error message.
• The envelope format of output descriptors can contain optional name and notes fields, and these are displayed by SeedTool for the associated output descriptor if present, but they are not currently editable.
• A seed's Envelope Notation is now hidden unless "Show Developer Functions" is turned on in the app Settings. When visible it is at the very bottom of the Seed Detail screen. The envelope notation shows any attachments or output descriptor associated with the seed, but does not reveal the seed itself.
• You can now long-press on a seed's Envelope Notation to share it.
• The "Clear" button for a seed's Creation Date and Output Descriptor fields now present confirmation alerts before clearing them.
• When using Seed Detail > Authenticate > Derive Key > Other Key Derivations > Output Descriptor the default export format is stil ur:crypto-output for compatibility, but a new button has been added to allow export as Gordian Envelope.

1.6 (70)

• The app now stores third-party attachments to seeds. See BCR-2023-006
• Displays Envelope Notation for seed (including any attachments) at bottom of Seed Detail view.
• Seed Envelope export now includes any attachments.
• Seed Envelope import now restores attachments.
• SSKR using envelopes now backs up seeds including attachments.
• Scan now support Seed and SSKR Envelopes that include attachments.
• NOTE: Printed backup seeds do not include attachments due to the fact that attachments can be arbitrarily large.
• Add Seed > SSKR now accepts a list of SSKR Envelopes, one per line.

1.6 (69)

• Fixed #199 Large SSKR Envelopes Overflow Print Page. When printed, SSKR Envelopes requiring more than 50 bytewords only show the last four bytewords.
• Updated the Envelope library to use the latest version. This is a breaking change, hopefully the last!
• All examples in the source repo Testing folder have been updated for compatibility.

1.6 (68)

• For seeds and HDKeys, wherever the master public key fingerprint is shown, it is now accompanied by a small LifeHash that matches the one displayed in SparrowWallet.
• Fixed #191 Bytewords SSKR Doesn't Work in Add Seed.
• Fixed #194 BIP39 mnemonics can now be decoded where words have been abbreviated to the first four letters.
• Fixed #197 NFC Write: Tag Not Connected

1.6 (67)

• SSKR backup now offers the option of exporting as Gordian Envelope or the legacy ur:crypto-sskr format with Envelope being the default. The major advantage of the new format is that it backs up all the seed's metadata (named, notes, creation date, etc.) and not just the raw key bytes. ur:crypto-sskr is still accepted for recovery.
• As Envelopes may be arbitrary size, when printing SSKR shares the option to put multiple shares as "coupons" on a single page has been removed.
• Seeds are now exported and imported as Gordian Envelope. ur:crypto-seed is still accepted for importing.
• Keys are now exported as Gordian Envelope. ur:crypto-hdkey is discontinued.
• All requests and responses are now formatted as Gordian Envelope. ur:crypto-psbt is still accepted for signing and may still be exported as the result of a signing request.
• Output descriptors are still exported as ur:crypto-output.
• Account descriptors are still exported as ur:crypto-account.
• Example seeds, PSBTs, and requests in the Testing folder have been updated to the new preferred formats.

1.6 (66)

• Fixed bug with CBOR serialization of master private keys and the public "master" keys directly derived from them (Issue #182).
• Clarified documentation (BCR-2020-007) for how we're representing pair-components in output descriptors (Issue #183).

1.6 (65)

Interim release.

1.6 (64)

Interim release (iOS only).

1.6 (63)

Interim release.

1.6 (62)

• Envelope format has changed, so the app has been updated to use the latest format for requests and responses.

1.6 (61)

• Requests and responses are now all based on the Envelope type.

1.6 (60)

• Now responds to crypto-request for an output descriptor. This will allow the upcoming Gordian Coordinator or other wallet apps to securely request an output descriptor for use in online wallets.
• Numerous other small changes and improvements throughout the app.
• A lot of code has been moved to where it can be shared between all Gordian apps, particularly the upcoming Gordian Coordinator. As such, this should be considered an early beta and all functionality should be thoroughly re-tested.

Summary of changes in version 1.5 (May 11, 2022)

NFC Improvements (Experimental!)

• Write crypto-seeds to NFC Tags.
• Write crypto-hdkeys to NFC Tags.
• Write crypto-requests to NFC Tags (developers only).
• Read crypto-requests from NFC Tags.
• Write crypto-responses to NFC Tags.

SSKR Improvements

• Write individual SSKR shares to NFC Tags.
• Print individual SSKR shares.
• Save individual SSKR shares as PDFs (using printing).

General bug fixes and improvements.

Summary of changes in version 1.4 (April 6, 2022)

I/O Improvements

• NFC Import: Allows import from NFC Tags.
• UR Import: Imports and processes "ur:" scheme strings.
• Clipboard Erasure: Erases clipboard in 1 minute when used for export (iOS only).
• File Saving: Exports to files, including MicroSDs and iCloud.
• SSKR Split: Allows individual export of SSKR shares, such as to different MicroSD cards.

New Data Details

• Descriptor Checksums: All output descriptors now include their checksum.
• Seed Fingerprints: All seed OIBs now display the fingerprint for their master HD key.
• Request Details: All crypto-requests now show notes and known key derivations.

Other Updates & Fixes

• Seed Request Fix: Parses crypto-requests for seeds using the latest spec.
• Other: Various UX improvements, interface standardizations, and small bug fixes.

1.4 (56)

• Fixed crash on Mac when exporting keys.

1.4 (55)

• #152 In the Seed Detail screen, the "Randomize" and "Clear Field" buttons that appear in the Seed Name field when editing it have been replaced with a menu button that includes "Randomize" and "Clear" commands, that only appears when the field is not being edited. This is to reduce the chance of the user accidentally changing the field.
• #114 When responding to a request for a key derivation that asks the user to select a seed, the pre-seed selection screen now shows information about the derivation path, as well as any note included with the request. This is in addition to showing this information on the request approval screen.
• The parsing for requests and responses was using an outdated format. The seed requests and responses now conform to the latest spec. The Seed Request QR in the Testing folder in the repo has also been updated.
• A crash at startup was observed when the most recent builds are run on an iPod Touch running iOS 15.3.1. Based on crash logs, I determined that this is because the CoreNFC framework is missing on the iPod Touch, causing a dynamic link failure at startup. This issue has been reported by other developers and according to this report an iPod Touch running iOS 15.1 does not crash. As I do not have an iPod Touch to test on, the only thing I was able to do in the next build was to set the CoreNFC framework to "weak link." This may avoid the immediate crash at startup, but the app may still crash in places where it attempts to call into CoreNFC. Further crash logs for this build need to be examined to see whether anything further can be done about this.

1.4 (54)

• Seed Tool now shows any associated note attached to requests for seeds or keys. It displays the note text in a distinctive style and warns the user to be careful about whether to trust what the note contains. To facilitate testing this, the "Show Example Request..." functions now include a dummy note.
• #114 When responding to Key Requests, Seed Tool now shows the requested derivation path's known name, if it corresponds to one, or a warning if it does not.
• #143 When long-pressing on the various parts of an Object Identity Block (OIB), and then choosing the Save to Files... option, suggested filenames are now consistent with the identified subject as well as the selected field of the OIB (LifeHash, Identifier, Detail, and Name). All suggested filenames for objects derived from seeds (such as HDKeys and Addresses) now start with the Seed Digest Identifier first and then the Digest Identifier of the derived object.
• #145 Added checksums to all Output Descriptors exported as text, as well as the filenames used with Save to File for descriptors.
• #147 Fixed crash when Scan view is invoked with camera permissions revoked in Settings > Privacy > Camera > Seed Tool.
• #148 Fixed so all Key Export views have the same export options, including Base58.

See Version History for previous builds.

Origin, Authors, Copyright & Licenses

Unless otherwise noted (either in this /README.md or in the file's header comments) the contents of this repository are Copyright © 2024 by Blockchain Commons, LLC, and are licensed under the spdx:BSD-2-Clause Plus Patent License.

In most cases, the authors, copyright, and license for each file reside in header comments in the source code. When it does not, we have attempted to attribute it accurately in the table below.

This table below also establishes provenance (repository of origin, permalink, and commit id) for files included from repositories that are outside of this repo. Contributors to these files are listed in the commit history for each repository, first with changes found in the commit history of this repo, then in changes in the commit history of their repo of their origin.

File	From	Commit	Authors & Copyright (c)	License
exception-to-the-rule.c or exception-folder	https://github.com/community/repo-name/PERMALINK	https://github.com/community/repo-name/commit/COMMITHASH	2020 Exception Author	MIT

Dependencies

To build Gordian Seed Tool you'll need to use the following tools:

• Xtools with Swift (or another Swift compiler)

Derived from....

Gordian Seed Tool incorporates:

• BCLibsSwift and thus a variety of crypto commons libraries.

Related to...

Blockchain Commons has two other seedtools:

• LetheKit — Our DIY hardware project contains a seedtool.
• seedtool-cli — A command-line version of seedtool.

We also have other related projects:

• keytool-cli — A command-line tool for a wide variety of key derivations.

Financial Support

Gordian Seed Tool is a project of Blockchain Commons. We are proudly a "not-for-profit" social benefit corporation committed to open source & open development. Our work is funded entirely by donations and collaborative partnerships with people like you. Every contribution will be spent on building open tools, technologies, and techniques that sustain and advance blockchain and internet security infrastructure and promote an open web.

To financially support further development of Gordian Seed Tool and other projects, please consider becoming a Patron of Blockchain Commons through ongoing monthly patronage as a GitHub Sponsor. You can also support Blockchain Commons with bitcoins at our BTCPay Server.

Contributing

We encourage public contributions through issues and pull requests! Please review CONTRIBUTING.md for details on our development process. All contributions to this repository require a GPG signed Contributor License Agreement.

Discussions

The best place to talk about Blockchain Commons and its projects is in our GitHub Discussions areas.

Gordian Developer Community. For standards and open-source developers who want to talk about interoperable wallet specifications, please use the Discussions area of the Gordian Developer Community repo. This is where you talk about Gordian specifications such as Gordian Envelope, bc-shamir, Sharded Secret Key Reconstruction, and bc-ur as well as the larger Gordian Architecture, its Principles of independence, privacy, resilience, and openness, and its macro-architectural ideas such as functional partition (including airgapping, the original name of this community).

Gordian User Community. For users of the Gordian reference apps, including Gordian Coordinator, Gordian Seed Tool, Gordian Server, Gordian Wallet, and SpotBit as well as our whole series of CLI apps. This is a place to talk about bug reports and feature requests as well as to explore how our reference apps embody the Gordian Principles.

Blockchain Commons Discussions. For developers, interns, and patrons of Blockchain Commons, please use the discussions area of the Community repo to talk about general Blockchain Commons issues, the intern program, or topics other than those covered by the Gordian Developer Community or the Gordian User Community.

Other Questions & Problems

As an open-source, open-development community, Blockchain Commons does not have the resources to provide direct support of our projects. Please consider the discussions area as a locale where you might get answers to questions. Alternatively, please use this repository's issues feature. Unfortunately, we can not make any promises on response time.

If your company requires support to use our projects, please feel free to contact us directly about options. We may be able to offer you a contract for support from one of our contributors, or we might be able to point you to another entity who can offer the contractual support that you need.

Credits

The following people directly contributed to this repository. You can add your name here by getting involved. The first step is learning how to contribute from our CONTRIBUTING.md documentation.

Name	Role	Github	Email	GPG Fingerprint
Christopher Allen	Principal Architect	@ChristopherA	<ChristopherA@LifeWithAlacrity.com>	FDFE 14A5 4ECB 30FC 5D22 74EF F8D3 6C91 3574 05ED
Wolf McNally	Project Lead	@WolfMcNally	<Wolf@WolfMcNally.com>	9436 52EE 3844 1760 C3DC  3536 4B6C 2FCF 8947 80AE

Responsible Disclosure

We want to keep all of our software safe for everyone. If you have discovered a security vulnerability, we appreciate your help in disclosing it to us in a responsible manner. We are unfortunately not able to offer bug bounties at this time.

We do ask that you offer us good faith and use best efforts not to leak information or harm any user, their data, or our developer community. Please give us a reasonable amount of time to fix the issue before you publish it. Do not defraud our users or us in the process of discovery. We promise not to bring legal action against researchers who point out a problem provided they do their best to follow the these guidelines.

Reporting a Vulnerability

Please report suspected security vulnerabilities in private via email to ChristopherA@BlockchainCommons.com (do not use this email for support). Please do NOT create publicly viewable issues for suspected security vulnerabilities.

The following keys may be used to communicate sensitive information to developers:

Name	Fingerprint
Christopher Allen	FDFE 14A5 4ECB 30FC 5D22 74EF F8D3 6C91 3574 05ED

You can import a key by running the following command with that individual’s fingerprint: gpg --recv-keys "<fingerprint>" Ensure that you put quotes around fingerprints that contain spaces.