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This repository provides an implementation ofThe Update Framework specificationand all references tonotary in this repository refer to the implementation of the clientand server aligning with theTUF specification.The most prominent use of this implementation is in Docker Content Trust (DCT).The first releasev0.1 was released in November, 2015.

This repository comprises of aserver and aclient for running and interactingwith trusted collections. See theservice architecture documentationfor more information.

The aim is to make the internet more secure by making it easy for people topublish and verify content. We often rely on TLS to secure our communicationswith a web server, which is inherently flawed, as any compromise of the serverenables malicious content to be substituted for the legitimate content.

Publishers can sign their content offline using keys kept highlysecure. Once the publisher is ready to make the content available, they canpush their signed trusted collection to thenotary server.

Consumers, having acquired the publisher's public key through a secure channel,can then communicate with anynotary server or (insecure) mirror, relyingonly on the publisher's key to determine the validity and integrity of thereceived content.

Thenotary client and server is based onThe Update Framework, a secure general design for the problem of software distribution and updates. By using TUF, thenotary client and server achieves a number of key advantages:

• Survivable Key Compromise: Content publishers must manage keys in order to sign their content. Signing keys may be compromised or lost so systems must be designed in order to be flexible and recoverable in the case of key compromise. TUF's notion of key roles is utilized to separate responsibilities across a hierarchy of keys such that loss of any particular key (except the root role) by itself is not fatal to the security of the system.
• Freshness Guarantees: Replay attacks are a common problem in designing secure systems, where previously valid payloads are replayed to trick another system. The same problem exists in the software update systems, where old signed can be presented as the most recent. Notary makes use of timestamping on publishing so that consumers can know that they are receiving the most up to date content. This is particularly important when dealing with software update where old vulnerable versions could be used to attack users.
• Configurable Trust Thresholds: Oftentimes there are a large number of publishers that are allowed to publish a particular piece of content. For example, open source projects where there are a number of core maintainers. Trust thresholds can be used so that content consumers require a configurable number of signatures on a piece of content in order to trust it. Using thresholds increases security so that loss of individual signing keys doesn't allow publishing of malicious content.
• Signing Delegation: To allow for flexible publishing of trusted collections, a content publisher can delegate part of their collection to another signer. This delegation is represented as signed metadata so that a consumer of the content can verify both the content and the delegation.
• Use of Existing Distribution: Notary's trust guarantees are not tied at all to particular distribution channels from which content is delivered. Therefore, trust can be added to any existing content delivery mechanism.
• Untrusted Mirrors and Transport: All of the notary metadata can be mirrored and distributed via arbitrary channels.

Any security vulnerabilities can be reported tosecurity@docker.com.

Seeservice architecture docs for more information about our threat model, which details the varying survivability and severities for key compromise as well as mitigations.

Below are the two public security audits:

• August 7, 2018 by Cure53 covering TUF and thenotary client and server.
• July 31, 2015 by NCC coveringnotary client and server.

Get thenotary client CLI binary fromthe official releases page or you canbuild one yourself.The version of thenotary server and signer should be greater than or equal to notary CLI's version to ensure feature compatibility (ex: CLI version 0.2, server/signer version >= 0.2), and all official releases are associated with GitHub tags.

To use the notary CLI with Docker hub images, have a look at notary'sgetting started docs.

For more advanced usage, see theadvanced usage docs.

To use the CLI against a localnotary server rather than against Docker Hub:

1. Ensure that you havedocker and docker-compose installed.

2. git clone https://github.com/theupdateframework/notary.git and from the cloned repository path,start up a localnotary server and signer and copy the config file and testing certs to yourlocal notary config directory:

   $ docker-compose build$ docker-compose up -d$ mkdir -p~/.notary&& cp cmd/notary/config.json cmd/notary/root-ca.crt~/.notary

3. Add127.0.0.1 notary-server to your/etc/hosts, or if using docker-machine,add$(docker-machine ip) notary-server).

You can run through the examples in thegetting started docs andadvanced usage docs, butwithout the-s (server URL) argument to thenotary command since the serverURL is specified already in the configuration, file you copied.

You can also leave off the-d ~/.docker/trust argument if you do not careto usenotary with Docker images.

To prevent mistakes in vendoring the go modules a buildscript has been added to properly vendor the modules using the correct version of Go to mitigate differences in CI and development environment.

Following procedure should be executed to upgrade a dependency. Preferably keep dependency upgrades in a separate commit from your code changes.

go get -u github.com/spf13/viperbuildscripts/circle-validate-vendor.shgit add.git commit -m"Upgraded github.com/spf13/viper"

Thebuildscripts/circle-validate-vendor.sh runsgo mod tidy andgo mod vendor using the given version of Go to prevent differences if you are for example running on a different version of Go.

Note that thelatest stable release is at the head of thereleases branch. The master branch is the developmentbranch and contains features for the next release.

Prerequisites:

• Go >= 1.12

SetGOPATH. Then, run:

$export GO111MODULE=on$ go get github.com/theupdateframework/notary# build with pkcs11 support by default to support yubikey$ go install -tags pkcs11 github.com/theupdateframework/notary/cmd/notary$ notary

To build the server and signer, rundocker-compose build.