WIP Prevent "Slow Retrieval" attacks

Signed-off-by: Lewis Marshall <lewis@lmars.net>
3 files changed
tree: 38c24672f23f53a172751f175f8d03a56ada23f5
  1. .travis.yml
  2. LICENSE
  3. MAINTAINERS
  4. README.md
  5. client/
  6. data/
  7. encrypted/
  8. errors.go
  9. keys/
  10. local_store.go
  11. repo.go
  12. repo_test.go
  13. signed/
  14. tuf/
  15. util/
README.md

go-tuf Build Status

This is a Go implementation of The Update Framework (TUF), a framework for securing software update systems.

Directory layout

A TUF repository has the following directory layout:

.
├── keys
├── repository
│   └── targets
└── staged
    └── targets

The directories contain the following files:

  • keys/ - signing keys with filename pattern ROLE-KEYID.json
  • repository/ - signed manifests
  • repository/targets/ - hashed target files
  • staged/ - either signed, unsigned or partially signed manifests
  • staged/targets/ - unhashed target files

CLI

go-tuf provides a CLI for managing a local TUF repository.

Install

go get github.com/flynn/go-tuf/tuf

Commands

tuf gen-key <role>

Generates a new signing key, serializes it to JSON and writes it to the keys directory. It also stages the addition of the new key to the root manifest.

tuf add <path>

Hashes a file at staged/targets/<path>, then updates and stages the targets manifest.

tuf remove <path>

Stages the removal of <path> from the targets manifest (it gets removed from the filesystem when the change is committed).

tuf snapshot [--compression=<format>]

Expects a staged, fully signed targets manifest and stages an appropriate snapshot manifest. It optionally compresses the staged targets manifest.

tuf timestamp

Stages an appropriate timestamp manifest. If a snapshot manifest is staged, it must be fully signed.

tuf sign ROLE

Signs the given role's staged manifest with all keys present in the keys directory for that role.

tuf commit

Verifies that all staged changes contain the correct information and are signed to the correct threshold, then moves the staged files into the repository directory. It also removes any target files which are not in the targets manifest.

tuf regenerate

Recreates the targets manifest based on the files in repository/targets.

tuf clean

Removes all staged manifests and targets.

tuf root-keys

Outputs a JSON serialized array of root keys to STDOUT. The resulting JSON should be distributed to clients for performing initial updates.

For a list of supported commands, run tuf help from the command line.

Examples

The following are example workflows for managing a TUF repository with the CLI.

The tree commands do not need to be run, but their output serve as an illustration of what files should exist after performing certain commands.

Although only two machines are referenced (i.e. the “root” and “repo” boxes), the workflows can be trivially extended to many signing machines by copying staged changes and signing on each machine in turn before finally committing.

Some key IDs are truncated for illustrative purposes.

Create signed root manifest

Generate a root key on the root box:

$ tuf gen-key root

$ tree .
.
├── keys
│   └── root-184b133f.json
├── repository
└── staged
    └── root.json

Copy staged/root.json from the root box to the repo box and generate targets, snapshot and timestamp keys:

$ tree .
.
├── keys
├── repository
└── staged
    └── root.json

$ tuf gen-key targets
$ tuf gen-key snapshot
$ tuf gen-key timestamp

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
└── staged
    └── root.json

Copy staged/root.json from the repo box back to the root box and sign it:

$ tree .
.
├── keys
│   ├── root-184b133f.json
├── repository
└── staged
    └── root.json

$ tuf sign root.json

The staged root.json can now be copied back to the repo box ready to be committed alongside other manifests.

Add a target file

Assuming a staged, signed root manifest and the file to add exists at staged/targets/foo/bar/baz.txt:

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
└── staged
    ├── root.json
    └── targets
        └── foo
            └── bar
                └── baz.txt

$ tuf add foo/bar/baz.txt

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
└── staged
    ├── root.json
    ├── targets
    │   └── foo
    │       └── bar
    │           └── baz.txt
    └── targets.json

$ tuf snapshot
$ tuf timestamp

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
└── staged
    ├── root.json
    ├── snapshot.json
    ├── targets
    │   └── foo
    │       └── bar
    │           └── baz.txt
    ├── targets.json
    └── timestamp.json

$ tuf commit

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged

Remove a target file

Assuming the file to remove is at repository/targets/foo/bar/baz.txt:

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged

$ tuf remove foo/bar/baz.txt

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged
    └── targets.json

$ tuf snapshot
$ tuf timestamp

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged
    ├── snapshot.json
    ├── targets.json
    └── timestamp.json

$ tuf commit

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets.json
│   └── timestamp.json
└── staged

Regenerate manifests based on targets tree

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged

$ tuf regenerate

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged
    └── targets.json

$ tuf snapshot
$ tuf timestamp

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged
    ├── snapshot.json
    ├── targets.json
    └── timestamp.json

$ tuf commit

$ tree .
.
├── keys
│   ├── snapshot-3e070e53.json
│   ├── targets-8cf4810c.json
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged

Update timestamp.json

$ tree .
.
├── keys
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged

$ tuf timestamp

$ tree .
.
├── keys
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged
    └── timestamp.json

$ tuf commit

$ tree .
.
├── keys
│   └── timestamp-a3768063.json
├── repository
│   ├── root.json
│   ├── snapshot.json
│   ├── targets
│   │   └── foo
│   │       └── bar
│   │           └── baz.txt
│   ├── targets.json
│   └── timestamp.json
└── staged

Modify key thresholds

TODO

Client

TODO