Key Transparency

Key Transparency provides a lookup service for generic records and a public, tamper-proof audit log of all record changes. While being publicly auditable, individual records are only revealed in response to queries for specific IDs.

Key Transparency can be used as a public key discovery service to authenticate users and provides a mechanism to keep the service accountable. It can be used by account owners to reliably see what keys have been associated with their account, and it can be used by senders to see how long an account has been active and stable before trusting it.

• Overview
• Design document
• API

Key Transparency is inspired by CONIKS and Certificate Transparency. It is a work-in-progress with the following milestones under development.

Key Transparency Client

Setup

1. Install Go 1.10.
2. go get -u github.com/google/keytransparency/cmd/keytransparency-client

Client operations

Generate a private key

keytransparency-client authorized-keys create-keyset -p password
keytransparency-client authorized-keys list-keyset -p password

Publish the public key

1. Get an OAuth client ID and download the generated JSON file to client_secret.json.

keytransparency-client post user@domain.com app1 --client-secret=client_secret.json --insecure -d 'dGVzdA==' #Base64

Get and verify a public key

keytransparency-client get <email> <app> --insecure --verbose
✓ Commitment verified.
✓ VRF verified.
✓ Sparse tree proof verified.
✓ Signed Map Head signature verified.
CT ✓ STH signature verified.
CT ✓ Consistency proof verified.
CT   New trusted STH: 2016-09-12 15:31:19.547 -0700 PDT
CT ✓ SCT signature verified. Saving SCT for future inclusion proof verification.
✓ Signed Map Head CT inclusion proof verified.
keys:<key:"app1" value:"test" >

Verify key history

keytransparency-client history <email> --insecure
Epoch |Timestamp                    |Profile
4     |Mon Sep 12 22:23:54 UTC 2016 |keys:<key:"app1" value:"test" >

Running the server

Install

1. OpenSSL
2. Docker
   • Docker Engine 1.13.0+ docker version -f '{{.Server.APIVersion}}'
   • Docker Compose 1.11.0+ docker-compose --version
3. go get -u github.com/google/keytransparency/...
4. go get -u github.com/google/trillian/...
5. ./scripts/prepare_server.sh -f

Run

1. Run Key Transparency

$ docker-compose up -d
Creating keytransparency_db_1 ...         done
Creating keytransparency_map_server_1 ... done
Creating keytransparency_log_server_1 ... done
Creating keytransparency_log_server_1 ... done
Creating keytransparency_server_1 ...     done
Creating keytransparency_sequencer_1 ...  done
Creating keytransparency_monitor_1 ...    done
Creating keytransparency_init_1 ...       done
Creating keytransparency_prometheus_1 ... done
Creating keytransparency_monitor_1 ...    done

2. Watch it Run

• docker-compose logs --tail=0 --follow
• Proof for app1/foo@bar.com
• Server configuration info
• Prometheus graphs

Development and Testing

Key Transparency and its Trillian backend use a MySQL database, which must be setup in order for the Key Transparency tests to work.

Directory structure

The directory structure of Key Transparency is as follows:

• cmd: binaries
  • keytransparency-client: Key Transparency CLI client.
  • keytransparency-sequencer: Key Transparency backend.
  • keytransparency-server: Key Transparency frontend.
• core: main library source code. Core libraries do not import impl.
  • adminserver: private api for creating new domains and apps.
  • api: gRPC API definitions.
  • crypto: verifiable random function and commitment implementations.
  • domain: interface for retrieving domain info from storage.
  • keyserver: keyserver implementation.
  • mutator: "smart contract" implementation.
  • sequencer: mutation executor.
• deploy: deployment configs:
  • docker: init helper.
  • kubernetes: kube deploy configs.
  • prometheus: monitoring docker module.
• docs: documentation.
• impl: environment specific modules:
  • authentication: authentication policy grpc interceptor.
  • authorization: OAuth and fake auth grpc interceptor.
  • integration: environment specific integration tests.
  • sql: mysql implementations of storage modules.
• scripts: scripts
  • deploy: deploy to Google Compute Engine.

Support

• Mailing list.