bump version

It may fail on unsupported platforms (e.g. keepkeylib does not supoprt Python 3)

.gitignore

@@ -55,3 +55,6 @@ docs/_build/
 
 # PyBuilder
 target/
+
+# Sublime Text
+*.sublime-*

.pylintrc

@@ -1,2 +1,2 @@
 [MESSAGES CONTROL]
-disable=invalid-name, missing-docstring, locally-disabled
+disable=invalid-name, missing-docstring, locally-disabled, unbalanced-tuple-unpacking

.travis.yml

@@ -3,10 +3,24 @@ language: python
 python:
   - "2.7"
   - "3.4"
+  - "3.5"
+
+cache:
+  directories:
+    - $HOME/.cache/pip
+
+addons:
+    apt:
+        packages:
+            - libudev-dev
+            - libusb-1.0-0-dev
+
+before_install:
+  - pip install -U setuptools pylint coverage pep8 pydocstyle "pip>=7.0" wheel
+  - pip install -e git+https://github.com/keepkey/python-keepkey@6e8baa8b935e830d05f87b6dfd9bc7c927a96dc3#egg=keepkey
 
 install:
-  - pip install ecdsa ed25519 semver  # test without trezorlib for now
-  - pip install pylint coverage pep8 pydocstyle
+  - pip install -e .
 
 script:
   - pep8 trezor_agent

README-GPG.md

@@ -0,0 +1,51 @@
+Note: the GPG-related code is still under development, so please try the current implementation
+and feel free to [report any issue](https://github.com/romanz/trezor-agent/issues) you have encountered.
+Thanks!
+
+# Installation
+
+First, verify that you have GPG 2.1.11+ installed
+([Debian](https://gist.github.com/vt0r/a2f8c0bcb1400131ff51),
+[macOS](https://sourceforge.net/p/gpgosx/docu/Download/)):
+
+```
+$ gpg2 --version | head -n1
+gpg (GnuPG) 2.1.15
+```
+
+This GPG version is included in [Ubuntu 16.04](https://launchpad.net/ubuntu/+source/gnupg2)
+and [Linux Mint 18](https://community.linuxmint.com/software/view/gnupg2).
+
+Update you TREZOR firmware to the latest version (at least v1.4.0).
+
+Install latest `trezor-agent` package from GitHub:
+```
+$ pip install --user git+https://github.com/romanz/trezor-agent.git
+```
+
+# Quickstart
+
+## Identity creation
+[![asciicast](https://asciinema.org/a/c2yodst21h9obttkn9wgf3783.png)](https://asciinema.org/a/c2yodst21h9obttkn9wgf3783)
+
+## Sample usage (signature and decryption)
+[![asciicast](https://asciinema.org/a/7x0h9tyoyu5ar6jc8y9oih0ba.png)](https://asciinema.org/a/7x0h9tyoyu5ar6jc8y9oih0ba)
+
+You can use GNU Privacy Assistant (GPA) in order to inspect the created keys
+and perform signature and decryption operations using:
+
+```
+$ sudo apt install gpa
+$ ./scripts/gpg-shell gpa
+```
+[![GPA](https://cloud.githubusercontent.com/assets/9900/20224804/053d7474-a849-11e6-87f3-ab07dc536158.png)](https://www.gnupg.org/related_software/swlist.html#gpa)
+
+## Git commit & tag signatures:
+Git can use GPG to sign and verify commits and tags (see [here](https://git-scm.com/book/en/v2/Git-Tools-Signing-Your-Work)):
+```
+$ git config --local gpg.program $(which gpg2)
+$ git commit --gpg-sign                      # create GPG-signed commit
+$ git log --show-signature -1                # verify commit signature
+$ git tag v1.2.3 --sign                      # create GPG-signed tag
+$ git tag v1.2.3 --verify                    # verify tag signature
+```

README-SSH.md

@@ -0,0 +1,87 @@
+# Screencast demo usage
+
+## Simple usage (single SSH session)
+[![Demo](https://asciinema.org/a/22959.png)](https://asciinema.org/a/22959)
+
+## Advanced usage (multiple SSH sessions from a sub-shell)
+[![Subshell](https://asciinema.org/a/33240.png)](https://asciinema.org/a/33240)
+
+## Using for GitHub SSH authentication (via `trezor-git` utility)
+[![GitHub](https://asciinema.org/a/38337.png)](https://asciinema.org/a/38337)
+
+## Loading multiple SSH identities from configuration file
+[![Config](https://asciinema.org/a/bdxxtgctk5syu56yfz8lcp7ny.png)](https://asciinema.org/a/bdxxtgctk5syu56yfz8lcp7ny)
+
+# Public key generation
+
+Run:
+
+	/tmp $ trezor-agent user@ssh.hostname.com -v > hostname.pub
+	2015-09-02 15:03:18,929 INFO         getting "ssh://user@ssh.hostname.com" public key from Trezor...
+	2015-09-02 15:03:23,342 INFO         disconnected from Trezor
+	/tmp $ cat hostname.pub
+	ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBGSevcDwmT+QaZPUEWUUjTeZRBICChxMKuJ7dRpBSF8+qt+8S1GBK5Zj8Xicc8SHG/SE/EXKUL2UU3kcUzE7ADQ= ssh://user@ssh.hostname.com
+
+Append `hostname.pub` contents to `/home/user/.ssh/authorized_keys`
+configuration file at `ssh.hostname.com`, so the remote server
+would allow you to login using the corresponding private key signature.
+
+# Usage
+
+Run:
+
+	/tmp $ trezor-agent user@ssh.hostname.com -v -c
+	2015-09-02 15:09:39,782 INFO         getting "ssh://user@ssh.hostname.com" public key from Trezor...
+	2015-09-02 15:09:44,430 INFO         please confirm user "roman" login to "ssh://user@ssh.hostname.com" using Trezor...
+	2015-09-02 15:09:46,152 INFO         signature status: OK
+	Linux lmde 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1+deb8u3 (2015-08-04) x86_64
+
+	The programs included with the Debian GNU/Linux system are free software;
+	the exact distribution terms for each program are described in the
+	individual files in /usr/share/doc/*/copyright.
+
+	Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
+	permitted by applicable law.
+	Last login: Tue Sep  1 15:57:05 2015 from localhost
+	~ $
+
+Make sure to confirm SSH signature on the Trezor device when requested.
+
+## Accessing remote Git/Mercurial repositories
+
+Use your SSH public key to access your remote repository (e.g. [GitHub](https://help.github.com/articles/adding-a-new-ssh-key-to-your-github-account/)):
+
+	$ trezor-agent -v -e ed25519 git@github.com | xclip
+
+Use the following Bash alias for convinient Git operations:
+
+	$ alias git_hub='trezor-agent -v -e ed25519 git@github.com -- git'
+
+Replace `git` with `git_hub` for remote operations:
+
+	$ git_hub push origin master
+
+The same works for Mercurial (e.g. on [BitBucket](https://confluence.atlassian.com/bitbucket/set-up-ssh-for-mercurial-728138122.html)):
+
+	$ trezor-agent -v -e ed25519 git@bitbucket.org -- hg push
+
+
+# Troubleshooting
+
+If SSH connection fails to work, please open an [issue](https://github.com/romanz/trezor-agent/issues)
+with a verbose log attached (by running `trezor-agent -vv`) .
+
+## Incompatible SSH options
+
+Note that your local SSH configuration may ignore `trezor-agent`, if it has `IdentitiesOnly` option set to `yes`.
+
+     IdentitiesOnly
+             Specifies that ssh(1) should only use the authentication identity files configured in
+             the ssh_config files, even if ssh-agent(1) or a PKCS11Provider offers more identities.
+             The argument to this keyword must be “yes” or “no”.
+             This option is intended for situations where ssh-agent offers many different identities.
+             The default is “no”.
+
+If you are failing to connect, try running:
+
+    $ trezor-agent -vv user@host -- ssh -vv -oIdentitiesOnly=no user@host

README.md

@@ -1,79 +1,61 @@
-# Using TREZOR as a hardware SSH agent
+# Using TREZOR as a hardware SSH/GPG agent
 
 [![Build Status](https://travis-ci.org/romanz/trezor-agent.svg?branch=master)](https://travis-ci.org/romanz/trezor-agent)
 [![Python Versions](https://img.shields.io/pypi/pyversions/trezor_agent.svg)](https://pypi.python.org/pypi/trezor_agent/)
 [![Package Version](https://img.shields.io/pypi/v/trezor_agent.svg)](https://pypi.python.org/pypi/trezor_agent/)
 [![Development Status](https://img.shields.io/pypi/status/trezor_agent.svg)](https://pypi.python.org/pypi/trezor_agent/)
 [![Downloads](https://img.shields.io/pypi/dm/trezor_agent.svg)](https://pypi.python.org/pypi/trezor_agent/)
-[![Chat](https://badges.gitter.im/romanz/trezor-agent.svg)](https://gitter.im/romanz/trezor-agent)
 
-See SatoshiLabs' blog post about this feature:
+See SatoshiLabs' blog posts about this feature:
 
-- https://medium.com/@satoshilabs/trezor-firmware-1-3-4-enables-ssh-login-86a622d7e609
-
-## Screencast demo usage
-
-### Simple usage (single SSH session)
-[![Demo](https://asciinema.org/a/22959.png)](https://asciinema.org/a/22959)
-
-### Advanced usage (multiple SSH sessions from a sub-shell)
-[![Subshell](https://asciinema.org/a/33240.png)](https://asciinema.org/a/33240)
-
-### Using for GitHub SSH authentication (via `trezor-git` utility)
-[![GitHub](https://asciinema.org/a/38337.png)](https://asciinema.org/a/38337)
+- [TREZOR Firmware 1.3.4 enables SSH login](https://medium.com/@satoshilabs/trezor-firmware-1-3-4-enables-ssh-login-86a622d7e609)
+- [TREZOR Firmware 1.3.6 — GPG Signing, SSH Login Updates and Advanced Transaction Features for Segwit](https://medium.com/@satoshilabs/trezor-firmware-1-3-6-20a7df6e692)
+- [TREZOR Firmware 1.4.0 — GPG decryption support](https://www.reddit.com/r/TREZOR/comments/50h8r9/new_trezor_firmware_fidou2f_and_initial_ethereum/d7420q7/)
 
 ## Installation
 
-First, make sure that the latest `trezorlib` Python package
+First, make sure that the latest [trezorlib](https://pypi.python.org/pypi/trezor) Python package
 is installed correctly (at least v0.6.6):
 
 	$ apt-get install python-dev libusb-1.0-0-dev libudev-dev
+	$ pip install -U setuptools pip
 	$ pip install Cython trezor
 
-Then, install the latest `trezor_agent` package:
+Make sure that your `udev` rules are configured [correctly](https://doc.satoshilabs.com/trezor-user/settingupchromeonlinux.html#manual-configuration-of-udev-rules).
+Then, install the latest [trezor_agent](https://pypi.python.org/pypi/trezor_agent) package:
 
 	$ pip install trezor_agent
 
-Finally, verify that you are running the latest TREZOR firmware version (at least v1.3.4):
+Or, directly from the latest source code (if `pip` doesn't work for you):
 
-	$ trezorctl get_features
+	$ git clone https://github.com/romanz/trezor-agent && cd trezor-agent
+	$ python setup.py build && python setup.py install
+
+Finally, verify that you are running the latest [TREZOR firmware](https://wallet.mytrezor.com/data/firmware/releases.json) version (at least v1.4.0):
+
+	$ trezorctl get_features | head
 	vendor: "bitcointrezor.com"
 	major_version: 1
-	minor_version: 3
-	patch_version: 4
+	minor_version: 4
+	patch_version: 0
 	...
 
-## Public key generation
-
-Run:
-
-	/tmp $ trezor-agent ssh.hostname.com -v > hostname.pub
-	2015-09-02 15:03:18,929 INFO         getting "ssh://ssh.hostname.com" public key from Trezor...
-	2015-09-02 15:03:23,342 INFO         disconnected from Trezor
-	/tmp $ cat hostname.pub
-	ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBGSevcDwmT+QaZPUEWUUjTeZRBICChxMKuJ7dRpBSF8+qt+8S1GBK5Zj8Xicc8SHG/SE/EXKUL2UU3kcUzE7ADQ= ssh://ssh.hostname.com
-
-Append `hostname.pub` contents to `~/.ssh/authorized_keys`
-configuration file at `ssh.hostname.com`, so the remote server
-would allow you to login using the corresponding private key signature.
+If you have an error regarding `protobuf` imports (after installing it), please see [this issue](https://github.com/romanz/trezor-agent/issues/28).
 
 ## Usage
 
-Run:
+For SSH, see the [following instructions](README-SSH.md) (for Windows support,
+see [trezor-ssh-agent](https://github.com/martin-lizner/trezor-ssh-agent) project (by Martin Lízner)).
 
-	/tmp $ trezor-agent ssh.hostname.com -v -c
-	2015-09-02 15:09:39,782 INFO         getting "ssh://ssh.hostname.com" public key from Trezor...
-	2015-09-02 15:09:44,430 INFO         please confirm user "roman" login to "ssh://ssh.hostname.com" using Trezor...
-	2015-09-02 15:09:46,152 INFO         signature status: OK
-	Linux lmde 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1+deb8u3 (2015-08-04) x86_64
+For GPG, see the [following instructions](README-GPG.md).
 
-	The programs included with the Debian GNU/Linux system are free software;
-	the exact distribution terms for each program are described in the
-	individual files in /usr/share/doc/*/copyright.
+See [here](https://github.com/romanz/python-trezor#pin-entering) for PIN entering instructions.
 
-	Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
-	permitted by applicable law.
-	Last login: Tue Sep  1 15:57:05 2015 from localhost
-	~ $
+## Troubleshooting
 
-Make sure to confirm SSH signature on the Trezor device when requested.
+If there is an import problem with the installed `protobuf` package,
+see [this issue](https://github.com/romanz/trezor-agent/issues/28) for fixing it.
+
+### Gitter
+
+Questions, suggestions and discussions are welcome: [![Chat](https://badges.gitter.im/romanz/trezor-agent.svg)](https://gitter.im/romanz/trezor-agent)

scripts/gpg-init

@@ -0,0 +1,34 @@
+#!/bin/bash
+set -eu
+
+gpg2 --version >/dev/null  # verify that GnuPG 2 is installed
+
+USER_ID="${1}"
+HOMEDIR=~/.gnupg/trezor
+CURVE=${CURVE:="nist256p1"}  # or "ed25519"
+TIMESTAMP=${TIMESTAMP:=`date +%s`}  # key creation timestamp
+
+# Prepare new GPG home directory for TREZOR-based identity
+rm -rf "${HOMEDIR}"
+mkdir -p "${HOMEDIR}"
+chmod 700 "${HOMEDIR}"
+
+# Generate new GPG identity and import into GPG keyring
+trezor-gpg-create -v "${USER_ID}" -t "${TIMESTAMP}" -e "${CURVE}" > "${HOMEDIR}/pubkey.asc"
+gpg2 --homedir "${HOMEDIR}" --import < "${HOMEDIR}/pubkey.asc"
+rm -f "${HOMEDIR}/S.gpg-agent"  # (otherwise, our agent won't be started automatically)
+
+# Make new GPG identity with "ultimate" trust (via its fingerprint)
+FINGERPRINT=$(gpg2 --homedir "${HOMEDIR}" --list-public-keys --with-fingerprint --with-colons | sed -n -E 's/^fpr:::::::::([0-9A-F]+):$/\1/p' | head -n1)
+echo "${FINGERPRINT}:6" | gpg2 --homedir "${HOMEDIR}" --import-ownertrust
+
+# Prepare GPG configuration file
+echo "# TREZOR-based GPG configuration
+agent-program $(which trezor-gpg-agent)
+personal-digest-preferences SHA512
+" | tee "${HOMEDIR}/gpg.conf"
+
+echo "# TREZOR-based GPG agent emulator
+log-file ${HOMEDIR}/gpg-agent.log
+verbosity 2
+" | tee "${HOMEDIR}/gpg-agent.conf"

scripts/gpg-shell

@@ -0,0 +1,28 @@
+#!/bin/bash
+set -eu
+
+gpg2 --version >/dev/null  # verify that GnuPG 2 is installed
+
+export GNUPGHOME=~/.gnupg/trezor
+
+CONFIG_PATH="${GNUPGHOME}/gpg-agent.conf"
+if [ ! -f ${CONFIG_PATH} ]
+then
+	echo "No configuration found: ${CONFIG_PATH}"
+	exit 1
+fi
+
+# Make sure that the device is unlocked before starting the shell
+trezor-gpg-unlock
+
+# Make sure TREZOR-based gpg-agent is running
+gpg-connect-agent --agent-program "$(which trezor-gpg-agent)" </dev/null
+
+COMMAND=$*
+if [ -z "${COMMAND}" ]
+then
+	gpg2 --list-public-keys
+	${SHELL}
+else
+	${COMMAND}
+fi

setup.py

@@ -3,13 +3,17 @@ from setuptools import setup
 
 setup(
     name='trezor_agent',
-    version='0.6.5',
+    version='0.8.2',
     description='Using Trezor as hardware SSH agent',
     author='Roman Zeyde',
     author_email='roman.zeyde@gmail.com',
     url='http://github.com/romanz/trezor-agent',
-    packages=['trezor_agent'],
-    install_requires=['ecdsa>=0.13', 'ed25519>=1.4', 'Cython>=0.23.4', 'trezor>=0.6.6', 'keepkey>=0.7.0', 'semver>=2.2'],
+    packages=['trezor_agent', 'trezor_agent.device', 'trezor_agent.gpg'],
+    install_requires=[
+        'ecdsa>=0.13', 'ed25519>=1.4', 'Cython>=0.23.4', 'protobuf>=3.0.0', 'semver>=2.2',
+        'trezor>=0.7.6', 'keepkey>=0.7.3', 'ledgerblue>=0.1.8',
+        'hidapi==0.7.99.post15'  # until https://github.com/keepkey/python-keepkey/pull/8 is merged
+    ],
     platforms=['POSIX'],
     classifiers=[
         'Environment :: Console',
@@ -21,6 +25,7 @@ setup(
         'Operating System :: POSIX',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3.4',
+        'Programming Language :: Python :: 3.5',
         'Topic :: Software Development :: Libraries :: Python Modules',
         'Topic :: System :: Networking',
         'Topic :: Communications',
@@ -29,6 +34,8 @@ setup(
     ],
     entry_points={'console_scripts': [
         'trezor-agent = trezor_agent.__main__:run_agent',
-        'trezor-git = trezor_agent.__main__:run_git',
+        'trezor-gpg-create = trezor_agent.gpg.__main__:main_create',
+        'trezor-gpg-agent = trezor_agent.gpg.__main__:main_agent',
+        'trezor-gpg-unlock = trezor_agent.gpg.__main__:auto_unlock',
     ]},
 )

tox.ini

@@ -1,5 +1,7 @@
 [tox]
-envlist = py27,py34
+envlist = py27,py3
+[pep8]
+max-line-length = 100
 [testenv]
 deps=
     pytest

trezor_agent/__main__.py

@@ -2,20 +2,19 @@
 import argparse
 import functools
 import logging
-import re
 import os
+import re
 import subprocess
 import sys
-import time
 
-from . import client, formats, protocol, server
+from . import client, device, formats, protocol, server, util
 
 log = logging.getLogger(__name__)
 
 
 def ssh_args(label):
     """Create SSH command for connecting specified server."""
-    identity = client.string_to_identity(label, identity_type=dict)
+    identity = device.interface.string_to_identity(label)
 
     args = []
     if 'port' in identity:
@@ -23,7 +22,22 @@ def ssh_args(label):
     if 'user' in identity:
         args += ['-l', identity['user']]
 
-    return ['ssh'] + args + [identity['host']]
+    return args + [identity['host']]
+
+
+def mosh_args(label):
+    """Create SSH command for connecting specified server."""
+    identity = device.interface.string_to_identity(label)
+
+    args = []
+    if 'port' in identity:
+        args += ['-p', identity['port']]
+    if 'user' in identity:
+        args += [identity['user']+'@'+identity['host']]
+    else:
+        args += [identity['host']]
+
+    return args
 
 
 def create_parser():
@@ -31,7 +45,7 @@ def create_parser():
     p = argparse.ArgumentParser()
     p.add_argument('-v', '--verbose', default=0, action='count')
 
-    curve_names = [name.decode('ascii') for name in formats.SUPPORTED_CURVES]
+    curve_names = [name for name in formats.SUPPORTED_CURVES]
     curve_names = ', '.join(sorted(curve_names))
     p.add_argument('-e', '--ecdsa-curve-name', metavar='CURVE',
                    default=formats.CURVE_NIST256,
@@ -53,6 +67,8 @@ def create_agent_parser():
                    help='run ${SHELL} as subprocess under SSH agent')
     g.add_argument('-c', '--connect', default=False, action='store_true',
                    help='connect to specified host via SSH')
+    g.add_argument('--mosh', default=False, action='store_true',
+                   help='connect to specified host via using Mosh')
 
     p.add_argument('identity', type=str, default=None,
                    help='proto://[user@]host[:port][/path]')
@@ -74,15 +90,6 @@ def create_git_parser():
     return p
 
 
-def setup_logging(verbosity):
-    """Configure logging for this tool."""
-    fmt = ('%(asctime)s %(levelname)-12s %(message)-100s '
-           '[%(filename)s:%(lineno)d]')
-    levels = [logging.WARNING, logging.INFO, logging.DEBUG]
-    level = levels[min(verbosity, len(levels) - 1)]
-    logging.basicConfig(format=fmt, level=level)
-
-
 def git_host(remote_name, attributes):
     """Extract git SSH host for specified remote name."""
     try:
@@ -98,24 +105,16 @@ def git_host(remote_name, attributes):
             continue
 
         url = matches[0].strip()
-        user, url = url.split('@', 1)
-        host, _ = url.split(':', 1)  # skip unused path (1 key per user@host)
-        return '{}@{}'.format(user, host)
+        match = re.match('(?P<user>.*?)@(?P<host>.*?):(?P<path>.*)', url)
+        if match:
+            return '{user}@{host}'.format(**match.groupdict())
 
 
-def ssh_sign(conn, label, blob):
-    """Perform SSH signature using given hardware device connection."""
-    now = time.strftime('%Y-%m-%d %H:%M:%S')
-    return conn.sign_ssh_challenge(label=label, blob=blob, visual=now)
-
-
-def run_server(conn, public_key, command, debug, timeout):
+def run_server(conn, public_keys, command, debug, timeout):
     """Common code for run_agent and run_git below."""
     try:
-        signer = functools.partial(ssh_sign, conn=conn)
-        public_key = formats.import_public_key(public_key)
-        log.info('using SSH public key: %s', public_key['fingerprint'])
-        handler = protocol.Handler(keys=[public_key], signer=signer,
+        signer = conn.sign_ssh_challenge
+        handler = protocol.Handler(keys=public_keys, signer=signer,
                                    debug=debug)
         with server.serve(handler=handler, timeout=timeout) as env:
             return server.run_process(command=command, environ=env)
@@ -123,55 +122,62 @@ def run_server(conn, public_key, command, debug, timeout):
         log.info('server stopped')
 
 
+def handle_connection_error(func):
+    """Fail with non-zero exit code."""
+    @functools.wraps(func)
+    def wrapper(*args, **kwargs):
+        try:
+            return func(*args, **kwargs)
+        except IOError as e:
+            log.error('Connection error: %s', e)
+            return 1
+    return wrapper
+
+
+def parse_config(fname):
+    """Parse config file into a list of Identity objects."""
+    contents = open(fname).read()
+    for identity_str, curve_name in re.findall(r'\<(.*?)\|(.*?)\>', contents):
+        yield device.interface.Identity(identity_str=identity_str,
+                                        curve_name=curve_name)
+
+
+@handle_connection_error
 def run_agent(client_factory=client.Client):
     """Run ssh-agent using given hardware client factory."""
     args = create_agent_parser().parse_args()
-    setup_logging(verbosity=args.verbose)
+    util.setup_logging(verbosity=args.verbose)
 
-    with client_factory(curve=args.ecdsa_curve_name) as conn:
-        label = args.identity
+    conn = client_factory(device=device.detect())
+    if args.identity.startswith('/'):
+        identities = list(parse_config(fname=args.identity))
+    else:
+        identities = [device.interface.Identity(
+            identity_str=args.identity, curve_name=args.ecdsa_curve_name)]
+    for index, identity in enumerate(identities):
+        identity.identity_dict['proto'] = 'ssh'
+        log.info('identity #%d: %s', index, identity)
+
+    public_keys = [conn.get_public_key(i) for i in identities]
+
+    if args.connect:
+        command = ['ssh'] + ssh_args(args.identity) + args.command
+    elif args.mosh:
+        command = ['mosh'] + mosh_args(args.identity) + args.command
+    else:
         command = args.command
 
-        public_key = conn.get_public_key(label=label)
+    use_shell = bool(args.shell)
+    if use_shell:
+        command = os.environ['SHELL']
 
-        if args.connect:
-            command = ssh_args(label) + args.command
-            log.debug('SSH connect: %r', command)
+    if not command:
+        for pk in public_keys:
+            sys.stdout.write(pk)
+        return
 
-        use_shell = bool(args.shell)
-        if use_shell:
-            command = os.environ['SHELL']
-            log.debug('using shell: %r', command)
-
-        if not command:
-            sys.stdout.write(public_key)
-            return
-
-        return run_server(conn=conn, public_key=public_key, command=command,
-                          debug=args.debug, timeout=args.timeout)
-
-
-def run_git(client_factory=client.Client):
-    """Run git under ssh-agent using given hardware client factory."""
-    args = create_git_parser().parse_args()
-    setup_logging(verbosity=args.verbose)
-
-    with client_factory(curve=args.ecdsa_curve_name) as conn:
-        label = git_host(args.remote, ['pushurl', 'url'])
-        if not label:
-            log.error('Could not find "%s" remote in .git/config', args.remote)
-            return
-
-        public_key = conn.get_public_key(label=label)
-
-        if not args.test:
-            if args.command:
-                command = ['git'] + args.command
-            else:
-                sys.stdout.write(public_key)
-                return
-        else:
-            command = ['ssh', '-T', label]
-
-        return run_server(conn=conn, public_key=public_key, command=command,
-                          debug=args.debug, timeout=args.timeout)
+    public_keys = [formats.import_public_key(pk) for pk in public_keys]
+    for pk, identity in zip(public_keys, identities):
+        pk['identity'] = identity
+    return run_server(conn=conn, public_keys=public_keys, command=command,
+                      debug=args.debug, timeout=args.timeout)

trezor_agent/client.py

@@ -3,13 +3,10 @@ Connection to hardware authentication device.
 
 It is used for getting SSH public keys and ECDSA signing of server requests.
 """
-import binascii
 import io
 import logging
-import re
-import struct
 
-from . import factory, formats, util
+from . import formats, util
 
 log = logging.getLogger(__name__)
 
@@ -17,128 +14,36 @@ log = logging.getLogger(__name__)
 class Client(object):
     """Client wrapper for SSH authentication device."""
 
-    def __init__(self, loader=factory.load, curve=formats.CURVE_NIST256):
+    def __init__(self, device):
         """Connect to hardware device."""
-        client_wrapper = loader()
-        self.client = client_wrapper.connection
-        self.identity_type = client_wrapper.identity_type
-        self.device_name = client_wrapper.device_name
-        self.call_exception = client_wrapper.call_exception
-        self.curve = curve
+        self.device = device
 
-    def __enter__(self):
-        """Start a session, and test connection."""
-        msg = 'Hello World!'
-        assert self.client.ping(msg) == msg
-        return self
+    def get_public_key(self, identity):
+        """Get SSH public key from the device."""
+        with self.device:
+            pubkey = self.device.pubkey(identity)
 
-    def __exit__(self, *args):
-        """Forget PIN, shutdown screen and disconnect."""
-        log.info('disconnected from %s', self.device_name)
-        self.client.clear_session()
-        self.client.close()
+        vk = formats.decompress_pubkey(pubkey=pubkey,
+                                       curve_name=identity.curve_name)
+        return formats.export_public_key(vk=vk,
+                                         label=str(identity))
 
-    def get_identity(self, label, index=0):
-        """Parse label string into Identity protobuf."""
-        identity = string_to_identity(label, self.identity_type)
-        identity.proto = 'ssh'
-        identity.index = index
-        return identity
-
-    def get_public_key(self, label):
-        """Get SSH public key corresponding to specified by label."""
-        identity = self.get_identity(label=label)
-        label = identity_to_string(identity)  # canonize key label
-        log.info('getting "%s" public key (%s) from %s...',
-                 label, self.curve, self.device_name)
-        addr = _get_address(identity)
-        node = self.client.get_public_node(n=addr,
-                                           ecdsa_curve_name=self.curve)
-
-        pubkey = node.node.public_key
-        vk = formats.decompress_pubkey(pubkey=pubkey, curve_name=self.curve)
-        return formats.export_public_key(vk=vk, label=label)
-
-    def sign_ssh_challenge(self, label, blob, visual=''):
-        """Sign given blob using a private key, specified by the label."""
-        identity = self.get_identity(label=label)
+    def sign_ssh_challenge(self, blob, identity):
+        """Sign given blob using a private key on the device."""
         msg = _parse_ssh_blob(blob)
         log.debug('%s: user %r via %r (%r)',
                   msg['conn'], msg['user'], msg['auth'], msg['key_type'])
-        log.debug('nonce: %s', binascii.hexlify(msg['nonce']))
-        log.debug('fingerprint: %s', msg['public_key']['fingerprint'])
+        log.debug('nonce: %r', msg['nonce'])
+        fp = msg['public_key']['fingerprint']
+        log.debug('fingerprint: %s', fp)
         log.debug('hidden challenge size: %d bytes', len(blob))
-        log.debug('visual challenge size: %d bytes = %r', len(visual), visual)
 
         log.info('please confirm user "%s" login to "%s" using %s...',
-                 msg['user'], label, self.device_name)
+                 msg['user'].decode('ascii'), identity,
+                 self.device)
 
-        try:
-            result = self.client.sign_identity(identity=identity,
-                                               challenge_hidden=blob,
-                                               challenge_visual=visual,
-                                               ecdsa_curve_name=self.curve)
-        except self.call_exception as e:
-            code, msg = e.args
-            log.warning('%s error #%s: %s', self.device_name, code, msg)
-            raise IOError(msg)  # close current connection, keep server open
-
-        verifying_key = formats.decompress_pubkey(pubkey=result.public_key,
-                                                  curve_name=self.curve)
-        key_type, blob = formats.serialize_verifying_key(verifying_key)
-        assert blob == msg['public_key']['blob']
-        assert key_type == msg['key_type']
-        assert len(result.signature) == 65
-        assert result.signature[:1] == bytearray([0])
-
-        return result.signature[1:]
-
-
-_identity_regexp = re.compile(''.join([
-    '^'
-    r'(?:(?P<proto>.*)://)?',
-    r'(?:(?P<user>.*)@)?',
-    r'(?P<host>.*?)',
-    r'(?::(?P<port>\w*))?',
-    r'(?P<path>/.*)?',
-    '$'
-]))
-
-
-def string_to_identity(s, identity_type):
-    """Parse string into Identity protobuf."""
-    m = _identity_regexp.match(s)
-    result = m.groupdict()
-    log.debug('parsed identity: %s', result)
-    kwargs = {k: v for k, v in result.items() if v}
-    return identity_type(**kwargs)
-
-
-def identity_to_string(identity):
-    """Dump Identity protobuf into its string representation."""
-    result = []
-    if identity.proto:
-        result.append(identity.proto + '://')
-    if identity.user:
-        result.append(identity.user + '@')
-    result.append(identity.host)
-    if identity.port:
-        result.append(':' + identity.port)
-    if identity.path:
-        result.append(identity.path)
-    return ''.join(result)
-
-
-def _get_address(identity):
-    index = struct.pack('<L', identity.index)
-    addr = index + identity_to_string(identity).encode('ascii')
-    log.debug('address string: %r', addr)
-    digest = formats.hashfunc(addr).digest()
-    s = io.BytesIO(bytearray(digest))
-
-    hardened = 0x80000000
-    address_n = [13] + list(util.recv(s, '<LLLL'))
-    return [(hardened | value) for value in address_n]
+        with self.device:
+            return self.device.sign(blob=blob, identity=identity)
 
 
 def _parse_ssh_blob(data):

trezor_agent/device/__init__.py

@@ -0,0 +1,27 @@
+"""Cryptographic hardware device management."""
+
+import logging
+
+from . import trezor
+from . import keepkey
+from . import ledger
+from . import interface
+
+log = logging.getLogger(__name__)
+
+DEVICE_TYPES = [
+    trezor.Trezor,
+    keepkey.KeepKey,
+    ledger.LedgerNanoS,
+]
+
+
+def detect():
+    """Detect the first available device and return it to the user."""
+    for device_type in DEVICE_TYPES:
+        try:
+            with device_type() as d:
+                return d
+        except interface.NotFoundError as e:
+            log.debug('device not found: %s', e)
+    raise IOError('No device found!')

trezor_agent/device/interface.py

@@ -0,0 +1,135 @@
+"""Device abstraction layer."""
+
+import hashlib
+import io
+import logging
+import re
+import struct
+
+from .. import formats, util
+
+log = logging.getLogger(__name__)
+
+_identity_regexp = re.compile(''.join([
+    '^'
+    r'(?:(?P<proto>.*)://)?',
+    r'(?:(?P<user>.*)@)?',
+    r'(?P<host>.*?)',
+    r'(?::(?P<port>\w*))?',
+    r'(?P<path>/.*)?',
+    '$'
+]))
+
+
+def string_to_identity(identity_str):
+    """Parse string into Identity dictionary."""
+    m = _identity_regexp.match(identity_str)
+    result = m.groupdict()
+    log.debug('parsed identity: %s', result)
+    return {k: v for k, v in result.items() if v}
+
+
+def identity_to_string(identity_dict):
+    """Dump Identity dictionary into its string representation."""
+    result = []
+    if identity_dict.get('proto'):
+        result.append(identity_dict['proto'] + '://')
+    if identity_dict.get('user'):
+        result.append(identity_dict['user'] + '@')
+    result.append(identity_dict['host'])
+    if identity_dict.get('port'):
+        result.append(':' + identity_dict['port'])
+    if identity_dict.get('path'):
+        result.append(identity_dict['path'])
+    log.debug('identity parts: %s', result)
+    return ''.join(result)
+
+
+class Error(Exception):
+    """Device-related error."""
+
+
+class NotFoundError(Error):
+    """Device could not be found."""
+
+
+class DeviceError(Error):
+    """"Error during device operation."""
+
+
+class Identity(object):
+    """Represent SLIP-0013 identity, together with a elliptic curve choice."""
+
+    def __init__(self, identity_str, curve_name):
+        """Configure for specific identity and elliptic curve usage."""
+        self.identity_dict = string_to_identity(identity_str)
+        self.curve_name = curve_name
+
+    def items(self):
+        """Return a copy of identity_dict items."""
+        return self.identity_dict.items()
+
+    def __str__(self):
+        """Return identity serialized to string."""
+        return '<{}|{}>'.format(identity_to_string(self.identity_dict), self.curve_name)
+
+    def get_bip32_address(self, ecdh=False):
+        """Compute BIP32 derivation address according to SLIP-0013/0017."""
+        index = struct.pack('<L', self.identity_dict.get('index', 0))
+        addr = index + identity_to_string(self.identity_dict).encode('ascii')
+        log.debug('bip32 address string: %r', addr)
+        digest = hashlib.sha256(addr).digest()
+        s = io.BytesIO(bytearray(digest))
+
+        hardened = 0x80000000
+        addr_0 = [13, 17][bool(ecdh)]
+        address_n = [addr_0] + list(util.recv(s, '<LLLL'))
+        return [(hardened | value) for value in address_n]
+
+    def get_curve_name(self, ecdh=False):
+        """Return correct curve name for device operations."""
+        if ecdh:
+            return formats.get_ecdh_curve_name(self.curve_name)
+        else:
+            return self.curve_name
+
+
+class Device(object):
+    """Abstract cryptographic hardware device interface."""
+
+    def __init__(self):
+        """C-tor."""
+        self.conn = None
+
+    def connect(self):
+        """Connect to device, otherwise raise NotFoundError."""
+        raise NotImplementedError()
+
+    def __enter__(self):
+        """Allow usage as context manager."""
+        self.conn = self.connect()
+        return self
+
+    def __exit__(self, *args):
+        """Close and mark as disconnected."""
+        try:
+            self.conn.close()
+        except Exception as e:  # pylint: disable=broad-except
+            log.exception('close failed: %s', e)
+        self.conn = None
+
+    def pubkey(self, identity, ecdh=False):
+        """Get public key (as bytes)."""
+        raise NotImplementedError()
+
+    def sign(self, identity, blob):
+        """Sign given blob and return the signature (as bytes)."""
+        raise NotImplementedError()
+
+    def ecdh(self, identity, pubkey):
+        """Get shared session key using Elliptic Curve Diffie-Hellman."""
+        raise NotImplementedError()
+
+    def __str__(self):
+        """Human-readable representation."""
+        return '{}'.format(self.__class__.__name__)

trezor_agent/device/keepkey.py

@@ -0,0 +1,37 @@
+"""KeepKey-related code (see https://www.keepkey.com/)."""
+
+from . import trezor
+from .. import formats
+
+
+def _verify_support(identity, ecdh):
+    """Make sure the device supports given configuration."""
+    protocol = identity.identity_dict['proto']
+    if protocol not in {'ssh'}:
+        raise NotImplementedError(
+            'Unsupported protocol: {}'.format(protocol))
+    if ecdh:
+        raise NotImplementedError('No support for ECDH')
+    if identity.curve_name not in {formats.CURVE_NIST256}:
+        raise NotImplementedError(
+            'Unsupported elliptic curve: {}'.format(identity.curve_name))
+
+
+class KeepKey(trezor.Trezor):
+    """Connection to KeepKey device."""
+
+    @property
+    def _defs(self):
+        from . import keepkey_defs
+        return keepkey_defs
+
+    required_version = '>=1.0.4'
+
+    def pubkey(self, identity, ecdh=False):
+        """Return public key."""
+        _verify_support(identity, ecdh)
+        return trezor.Trezor.pubkey(self, identity=identity, ecdh=ecdh)
+
+    def ecdh(self, identity, pubkey):
+        """No support for ECDH in KeepKey firmware."""
+        _verify_support(identity, ecdh=True)

trezor_agent/device/keepkey_defs.py

@@ -0,0 +1,8 @@
+"""KeepKey-related definitions."""
+
+# pylint: disable=unused-import
+from keepkeylib.client import KeepKeyClient as Client
+from keepkeylib.client import CallException
+from keepkeylib.transport_hid import HidTransport
+from keepkeylib.messages_pb2 import PassphraseAck
+from keepkeylib.types_pb2 import IdentityType

trezor_agent/device/ledger.py

@@ -0,0 +1,111 @@
+"""Ledger-related code (see https://www.ledgerwallet.com/)."""
+
+import binascii
+import logging
+import struct
+
+from ledgerblue import comm
+
+from . import interface
+
+log = logging.getLogger(__name__)
+
+
+def _expand_path(path):
+    """Convert BIP32 path into bytes."""
+    return b''.join((struct.pack('>I', e) for e in path))
+
+
+def _convert_public_key(ecdsa_curve_name, result):
+    """Convert Ledger reply into PublicKey object."""
+    if ecdsa_curve_name == 'nist256p1':
+        if (result[64] & 1) != 0:
+            result = bytearray([0x03]) + result[1:33]
+        else:
+            result = bytearray([0x02]) + result[1:33]
+    else:
+        result = result[1:]
+        keyX = bytearray(result[0:32])
+        keyY = bytearray(result[32:][::-1])
+        if (keyX[31] & 1) != 0:
+            keyY[31] |= 0x80
+        result = b'\x00' + bytes(keyY)
+    return bytes(result)
+
+
+class LedgerNanoS(interface.Device):
+    """Connection to Ledger Nano S device."""
+
+    def connect(self):
+        """Enumerate and connect to the first USB HID interface."""
+        try:
+            return comm.getDongle()
+        except comm.CommException as e:
+            raise interface.NotFoundError(
+                '{} not connected: "{}"'.format(self, e))
+
+    def pubkey(self, identity, ecdh=False):
+        """Get PublicKey object for specified BIP32 address and elliptic curve."""
+        curve_name = identity.get_curve_name(ecdh)
+        path = _expand_path(identity.get_bip32_address(ecdh))
+        if curve_name == 'nist256p1':
+            p2 = '01'
+        else:
+            p2 = '02'
+        apdu = '800200' + p2
+        apdu = binascii.unhexlify(apdu)
+        apdu += bytearray([len(path) + 1, len(path) // 4])
+        apdu += path
+        result = bytearray(self.conn.exchange(bytes(apdu)))[1:]
+        return _convert_public_key(curve_name, result)
+
+    def sign(self, identity, blob):
+        """Sign given blob and return the signature (as bytes)."""
+        path = _expand_path(identity.get_bip32_address(ecdh=False))
+        if identity.identity_dict['proto'] == 'ssh':
+            ins = '04'
+            p1 = '00'
+        else:
+            ins = '08'
+            p1 = '00'
+        if identity.curve_name == 'nist256p1':
+            p2 = '81' if identity.identity_dict['proto'] == 'ssh' else '01'
+        else:
+            p2 = '82' if identity.identity_dict['proto'] == 'ssh' else '02'
+        apdu = '80' + ins + p1 + p2
+        apdu = binascii.unhexlify(apdu)
+        apdu += bytearray([len(blob) + len(path) + 1])
+        apdu += bytearray([len(path) // 4]) + path
+        apdu += blob
+        result = bytearray(self.conn.exchange(bytes(apdu)))
+        if identity.curve_name == 'nist256p1':
+            offset = 3
+            length = result[offset]
+            r = result[offset+1:offset+1+length]
+            if r[0] == 0:
+                r = r[1:]
+            offset = offset + 1 + length + 1
+            length = result[offset]
+            s = result[offset+1:offset+1+length]
+            if s[0] == 0:
+                s = s[1:]
+            offset = offset + 1 + length
+            return bytes(r) + bytes(s)
+        else:
+            return bytes(result[:64])
+
+    def ecdh(self, identity, pubkey):
+        """Get shared session key using Elliptic Curve Diffie-Hellman."""
+        path = _expand_path(identity.get_bip32_address(ecdh=True))
+        if identity.curve_name == 'nist256p1':
+            p2 = '01'
+        else:
+            p2 = '02'
+        apdu = '800a00' + p2
+        apdu = binascii.unhexlify(apdu)
+        apdu += bytearray([len(pubkey) + len(path) + 1])
+        apdu += bytearray([len(path) // 4]) + path
+        apdu += pubkey
+        result = bytearray(self.conn.exchange(bytes(apdu)))
+        assert result[0] == 0x04
+        return bytes(result)

trezor_agent/device/trezor.py

@@ -0,0 +1,108 @@
+"""TREZOR-related code (see http://bitcointrezor.com/)."""
+
+import binascii
+import logging
+import semver
+
+from . import interface
+
+log = logging.getLogger(__name__)
+
+
+class Trezor(interface.Device):
+    """Connection to TREZOR device."""
+
+    @property
+    def _defs(self):
+        from . import trezor_defs
+        return trezor_defs
+
+    required_version = '>=1.4.0'
+
+    def connect(self):
+        """Enumerate and connect to the first USB HID interface."""
+        def empty_passphrase_handler(_):
+            return self._defs.PassphraseAck(passphrase='')
+
+        for d in self._defs.HidTransport.enumerate():
+            log.debug('endpoint: %s', d)
+            transport = self._defs.HidTransport(d)
+            connection = self._defs.Client(transport)
+            connection.callback_PassphraseRequest = empty_passphrase_handler
+            f = connection.features
+            log.debug('connected to %s %s', self, f.device_id)
+            log.debug('label    : %s', f.label)
+            log.debug('vendor   : %s', f.vendor)
+            current_version = '{}.{}.{}'.format(f.major_version,
+                                                f.minor_version,
+                                                f.patch_version)
+            log.debug('version  : %s', current_version)
+            log.debug('revision : %s', binascii.hexlify(f.revision))
+            if not semver.match(current_version, self.required_version):
+                fmt = ('Please upgrade your {} firmware to {} version'
+                       ' (current: {})')
+                raise ValueError(fmt.format(self, self.required_version,
+                                            current_version))
+            connection.ping(msg='', pin_protection=True)  # unlock PIN
+            return connection
+        raise interface.NotFoundError('{} not connected'.format(self))
+
+    def close(self):
+        """Close connection."""
+        self.conn.close()
+
+    def pubkey(self, identity, ecdh=False):
+        """Return public key."""
+        curve_name = identity.get_curve_name(ecdh=ecdh)
+        log.debug('"%s" getting public key (%s) from %s',
+                  identity, curve_name, self)
+        addr = identity.get_bip32_address(ecdh=ecdh)
+        result = self.conn.get_public_node(n=addr,
+                                           ecdsa_curve_name=curve_name)
+        log.debug('result: %s', result)
+        return result.node.public_key
+
+    def _identity_proto(self, identity):
+        result = self._defs.IdentityType()
+        for name, value in identity.items():
+            setattr(result, name, value)
+        return result
+
+    def sign(self, identity, blob):
+        """Sign given blob and return the signature (as bytes)."""
+        curve_name = identity.get_curve_name(ecdh=False)
+        log.debug('"%s" signing %r (%s) on %s',
+                  identity, blob, curve_name, self)
+        try:
+            result = self.conn.sign_identity(
+                identity=self._identity_proto(identity),
+                challenge_hidden=blob,
+                challenge_visual='',
+                ecdsa_curve_name=curve_name)
+            log.debug('result: %s', result)
+            assert len(result.signature) == 65
+            assert result.signature[:1] == b'\x00'
+            return result.signature[1:]
+        except self._defs.CallException as e:
+            msg = '{} error: {}'.format(self, e)
+            log.debug(msg, exc_info=True)
+            raise interface.DeviceError(msg)
+
+    def ecdh(self, identity, pubkey):
+        """Get shared session key using Elliptic Curve Diffie-Hellman."""
+        curve_name = identity.get_curve_name(ecdh=True)
+        log.debug('"%s" shared session key (%s) for %r from %s',
+                  identity, curve_name, pubkey, self)
+        try:
+            result = self.conn.get_ecdh_session_key(
+                identity=self._identity_proto(identity),
+                peer_public_key=pubkey,
+                ecdsa_curve_name=curve_name)
+            log.debug('result: %s', result)
+            assert len(result.session_key) in {65, 33}  # NIST256 or Curve25519
+            assert result.session_key[:1] == b'\x04'
+            return result.session_key
+        except self._defs.CallException as e:
+            msg = '{} error: {}'.format(self, e)
+            log.debug(msg, exc_info=True)
+            raise interface.DeviceError(msg)

trezor_agent/device/trezor_defs.py

@@ -0,0 +1,8 @@
+"""TREZOR-related definitions."""
+
+# pylint: disable=unused-import
+from trezorlib.client import TrezorClient as Client
+from trezorlib.client import CallException
+from trezorlib.transport_hid import HidTransport
+from trezorlib.messages_pb2 import PassphraseAck
+from trezorlib.types_pb2 import IdentityType

trezor_agent/factory.py

@@ -1,92 +0,0 @@
-"""Thin wrapper around trezor/keepkey libraries."""
-import binascii
-import collections
-import logging
-
-import semver
-
-log = logging.getLogger(__name__)
-
-ClientWrapper = collections.namedtuple(
-    'ClientWrapper',
-    ['connection', 'identity_type', 'device_name', 'call_exception'])
-
-
-# pylint: disable=too-many-arguments
-def _load_client(name, client_type, hid_transport,
-                 passphrase_ack, identity_type,
-                 required_version, call_exception):
-
-    def empty_passphrase_handler(_):
-        return passphrase_ack(passphrase='')
-
-    for d in hid_transport.enumerate():
-        connection = client_type(hid_transport(d))
-        connection.callback_PassphraseRequest = empty_passphrase_handler
-        f = connection.features
-        log.debug('connected to %s %s', name, f.device_id)
-        log.debug('label    : %s', f.label)
-        log.debug('vendor   : %s', f.vendor)
-        current_version = '{}.{}.{}'.format(f.major_version,
-                                            f.minor_version,
-                                            f.patch_version)
-        log.debug('version  : %s', current_version)
-        log.debug('revision : %s', binascii.hexlify(f.revision))
-        if not semver.match(current_version, required_version):
-            fmt = 'Please upgrade your {} firmware to {} version (current: {})'
-            raise ValueError(fmt.format(name,
-                                        required_version,
-                                        current_version))
-        yield ClientWrapper(connection=connection,
-                            identity_type=identity_type,
-                            device_name=name,
-                            call_exception=call_exception)
-
-
-def _load_trezor():
-    # pylint: disable=import-error
-    from trezorlib.client import TrezorClient, CallException
-    from trezorlib.transport_hid import HidTransport
-    from trezorlib.messages_pb2 import PassphraseAck
-    from trezorlib.types_pb2 import IdentityType
-    return _load_client(name='Trezor',
-                        client_type=TrezorClient,
-                        hid_transport=HidTransport,
-                        passphrase_ack=PassphraseAck,
-                        identity_type=IdentityType,
-                        required_version='>=1.3.4',
-                        call_exception=CallException)
-
-
-def _load_keepkey():
-    # pylint: disable=import-error
-    from keepkeylib.client import KeepKeyClient, CallException
-    from keepkeylib.transport_hid import HidTransport
-    from keepkeylib.messages_pb2 import PassphraseAck
-    from keepkeylib.types_pb2 import IdentityType
-    return _load_client(name='KeepKey',
-                        client_type=KeepKeyClient,
-                        hid_transport=HidTransport,
-                        passphrase_ack=PassphraseAck,
-                        identity_type=IdentityType,
-                        required_version='>=1.0.4',
-                        call_exception=CallException)
-
-LOADERS = [
-    _load_trezor,
-    _load_keepkey
-]
-
-
-def load(loaders=None):
-    """Load a single device, via specified loaders' list."""
-    loaders = loaders if loaders is not None else LOADERS
-    device_list = []
-    for loader in loaders:
-        device_list.extend(loader())
-
-    if len(device_list) == 1:
-        return device_list[0]
-
-    msg = '{:d} devices found'.format(len(device_list))
-    raise IOError(msg)

trezor_agent/formats.py

@@ -11,11 +11,15 @@ from . import util
 
 log = logging.getLogger(__name__)
 
-# Supported ECDSA curves
-CURVE_NIST256 = b'nist256p1'
-CURVE_ED25519 = b'ed25519'
+# Supported ECDSA curves (for SSH and GPG)
+CURVE_NIST256 = 'nist256p1'
+CURVE_ED25519 = 'ed25519'
 SUPPORTED_CURVES = {CURVE_NIST256, CURVE_ED25519}
 
+# Supported ECDH curves (for GPG)
+ECDH_NIST256 = 'nist256p1'
+ECDH_CURVE25519 = 'curve25519'
+
 # SSH key types
 SSH_NIST256_DER_OCTET = b'\x04'
 SSH_NIST256_KEY_PREFIX = b'ecdsa-sha2-'
@@ -41,7 +45,7 @@ def parse_pubkey(blob):
     """
     Parse SSH public key from given blob.
 
-    Cnstruct a verifier for ECDSA signatures.
+    Construct a verifier for ECDSA signatures.
     The verifier returns the signatures in the required SSH format.
     Currently, NIST256P1 and ED25519 elliptic curves are supported.
     """
@@ -134,7 +138,8 @@ def decompress_pubkey(pubkey, curve_name):
     if len(pubkey) == 33:
         decompress = {
             CURVE_NIST256: _decompress_nist256,
-            CURVE_ED25519: _decompress_ed25519
+            CURVE_ED25519: _decompress_ed25519,
+            ECDH_CURVE25519: _decompress_ed25519,
         }[curve_name]
         vk = decompress(pubkey)
 
@@ -192,3 +197,12 @@ def import_public_key(line):
     assert result['type'] == file_type.encode('ascii')
     log.debug('loaded %s public key: %s', file_type, result['fingerprint'])
     return result
+
+
+def get_ecdh_curve_name(signature_curve_name):
+    """Return appropriate curve for ECDH for specified signing curve."""
+    return {
+        CURVE_NIST256: ECDH_NIST256,
+        CURVE_ED25519: ECDH_CURVE25519,
+        ECDH_CURVE25519: ECDH_CURVE25519,
+    }[signature_curve_name]

trezor_agent/gpg/__init__.py

@@ -0,0 +1,9 @@
+"""
+TREZOR support for ECDSA GPG signatures.
+
+See these links for more details:
+ - https://www.gnupg.org/faq/whats-new-in-2.1.html
+ - https://tools.ietf.org/html/rfc4880
+ - https://tools.ietf.org/html/rfc6637
+ - https://tools.ietf.org/html/draft-irtf-cfrg-eddsa-05
+"""

trezor_agent/gpg/__main__.py

@@ -0,0 +1,126 @@
+#!/usr/bin/env python
+"""Create signatures and export public keys for GPG using TREZOR."""
+import argparse
+import contextlib
+import logging
+import os
+import sys
+import time
+
+import semver
+
+from . import agent, client, encode, keyring, protocol
+from .. import device, formats, server, util
+
+log = logging.getLogger(__name__)
+
+
+def run_create(args):
+    """Generate a new pubkey for a new/existing GPG identity."""
+    log.warning('NOTE: in order to re-generate the exact same GPG key later, '
+                'run this command with "--time=%d" commandline flag (to set '
+                'the timestamp of the GPG key manually).', args.time)
+    d = client.Client(user_id=args.user_id, curve_name=args.ecdsa_curve)
+    verifying_key = d.pubkey(ecdh=False)
+    decryption_key = d.pubkey(ecdh=True)
+
+    if args.subkey:  # add as subkey
+        log.info('adding %s GPG subkey for "%s" to existing key',
+                 args.ecdsa_curve, args.user_id)
+        # subkey for signing
+        signing_key = protocol.PublicKey(
+            curve_name=args.ecdsa_curve, created=args.time,
+            verifying_key=verifying_key, ecdh=False)
+        # subkey for encryption
+        encryption_key = protocol.PublicKey(
+            curve_name=formats.get_ecdh_curve_name(args.ecdsa_curve),
+            created=args.time, verifying_key=decryption_key, ecdh=True)
+        primary_bytes = keyring.export_public_key(args.user_id)
+        result = encode.create_subkey(primary_bytes=primary_bytes,
+                                      subkey=signing_key,
+                                      signer_func=d.sign)
+        result = encode.create_subkey(primary_bytes=result,
+                                      subkey=encryption_key,
+                                      signer_func=d.sign)
+    else:  # add as primary
+        log.info('creating new %s GPG primary key for "%s"',
+                 args.ecdsa_curve, args.user_id)
+        # primary key for signing
+        primary = protocol.PublicKey(
+            curve_name=args.ecdsa_curve, created=args.time,
+            verifying_key=verifying_key, ecdh=False)
+        # subkey for encryption
+        subkey = protocol.PublicKey(
+            curve_name=formats.get_ecdh_curve_name(args.ecdsa_curve),
+            created=args.time, verifying_key=decryption_key, ecdh=True)
+
+        result = encode.create_primary(user_id=args.user_id,
+                                       pubkey=primary,
+                                       signer_func=d.sign)
+        result = encode.create_subkey(primary_bytes=result,
+                                      subkey=subkey,
+                                      signer_func=d.sign)
+
+    sys.stdout.write(protocol.armor(result, 'PUBLIC KEY BLOCK'))
+
+
+def main_create():
+    """Main function for GPG identity creation."""
+    p = argparse.ArgumentParser()
+    p.add_argument('user_id')
+    p.add_argument('-e', '--ecdsa-curve', default='nist256p1')
+    p.add_argument('-t', '--time', type=int, default=int(time.time()))
+    p.add_argument('-v', '--verbose', default=0, action='count')
+    p.add_argument('-s', '--subkey', default=False, action='store_true')
+
+    args = p.parse_args()
+    util.setup_logging(verbosity=args.verbose)
+    log.warning('This GPG tool is still in EXPERIMENTAL mode, '
+                'so please note that the API and features may '
+                'change without backwards compatibility!')
+
+    existing_gpg = keyring.gpg_version().decode('ascii')
+    required_gpg = '>=2.1.11'
+    if semver.match(existing_gpg, required_gpg):
+        run_create(args)
+    else:
+        log.error('Existing gpg2 has version "%s" (%s required)',
+                  existing_gpg, required_gpg)
+
+
+def main_agent():
+    """Run a simple GPG-agent server."""
+    home_dir = os.environ.get('GNUPGHOME', os.path.expanduser('~/.gnupg/trezor'))
+    config_file = os.path.join(home_dir, 'gpg-agent.conf')
+    if not os.path.exists(config_file):
+        msg = 'No configuration file found: {}'.format(config_file)
+        raise IOError(msg)
+
+    lines = (line.strip() for line in open(config_file))
+    lines = (line for line in lines if line and not line.startswith('#'))
+    config = dict(line.split(' ', 1) for line in lines)
+
+    util.setup_logging(verbosity=int(config['verbosity']),
+                       filename=config['log-file'])
+    sock_path = keyring.get_agent_sock_path()
+    with server.unix_domain_socket_server(sock_path) as sock:
+        for conn in agent.yield_connections(sock):
+            with contextlib.closing(conn):
+                try:
+                    agent.handle_connection(conn)
+                except StopIteration:
+                    log.info('stopping gpg-agent')
+                    return
+                except Exception as e:  # pylint: disable=broad-except
+                    log.exception('gpg-agent failed: %s', e)
+
+
+def auto_unlock():
+    """Automatically unlock first found device (used for `gpg-shell`)."""
+    p = argparse.ArgumentParser()
+    p.add_argument('-v', '--verbose', default=0, action='count')
+
+    args = p.parse_args()
+    util.setup_logging(verbosity=args.verbose)
+    d = device.detect()
+    log.info('unlocked %s device', d)

trezor_agent/gpg/agent.py

@@ -0,0 +1,152 @@
+"""GPG-agent utilities."""
+import binascii
+import logging
+
+from . import decode, client, keyring, protocol
+from .. import util
+
+log = logging.getLogger(__name__)
+
+
+def yield_connections(sock):
+    """Run a server on the specified socket."""
+    while True:
+        log.debug('waiting for connection on %s', sock.getsockname())
+        try:
+            conn, _ = sock.accept()
+        except KeyboardInterrupt:
+            return
+        conn.settimeout(None)
+        log.debug('accepted connection on %s', sock.getsockname())
+        yield conn
+
+
+def serialize(data):
+    """Serialize data according to ASSUAN protocol."""
+    for c in [b'%', b'\n', b'\r']:
+        escaped = '%{:02X}'.format(ord(c)).encode('ascii')
+        data = data.replace(c, escaped)
+    return data
+
+
+def sig_encode(r, s):
+    """Serialize ECDSA signature data into GPG S-expression."""
+    r = serialize(util.num2bytes(r, 32))
+    s = serialize(util.num2bytes(s, 32))
+    return b'(7:sig-val(5:ecdsa(1:r32:' + r + b')(1:s32:' + s + b')))'
+
+
+def open_connection(keygrip_bytes):
+    """
+    Connect to the device for the specified keygrip.
+
+    Parse GPG public key to find the first user ID, which is used to
+    specify the correct signature/decryption key on the device.
+    """
+    pubkey_dict, user_ids = decode.load_by_keygrip(
+        pubkey_bytes=keyring.export_public_keys(),
+        keygrip=keygrip_bytes)
+    # We assume the first user ID is used to generate TREZOR-based GPG keys.
+    user_id = user_ids[0]['value'].decode('ascii')
+    curve_name = protocol.get_curve_name_by_oid(pubkey_dict['curve_oid'])
+    ecdh = (pubkey_dict['algo'] == protocol.ECDH_ALGO_ID)
+
+    conn = client.Client(user_id, curve_name=curve_name)
+    pubkey = protocol.PublicKey(
+        curve_name=curve_name, created=pubkey_dict['created'],
+        verifying_key=conn.pubkey(ecdh=ecdh), ecdh=ecdh)
+    assert pubkey.key_id() == pubkey_dict['key_id']
+    assert pubkey.keygrip() == keygrip_bytes
+    return conn
+
+
+def pksign(keygrip, digest, algo):
+    """Sign a message digest using a private EC key."""
+    log.debug('signing %r digest (algo #%s)', digest, algo)
+    keygrip_bytes = binascii.unhexlify(keygrip)
+    conn = open_connection(keygrip_bytes)
+    r, s = conn.sign(binascii.unhexlify(digest))
+    result = sig_encode(r, s)
+    log.debug('result: %r', result)
+    return result
+
+
+def _serialize_point(data):
+    prefix = '{}:'.format(len(data)).encode('ascii')
+    # https://www.gnupg.org/documentation/manuals/assuan/Server-responses.html
+    return b'(5:value' + serialize(prefix + data) + b')'
+
+
+def parse_ecdh(line):
+    """Parse ECDH request and return remote public key."""
+    prefix, line = line.split(b' ', 1)
+    assert prefix == b'D'
+    exp, leftover = keyring.parse(keyring.unescape(line))
+    log.debug('ECDH s-exp: %r', exp)
+    assert not leftover
+    label, exp = exp
+    assert label == b'enc-val'
+    assert exp[0] == b'ecdh'
+    items = exp[1:]
+    log.debug('ECDH parameters: %r', items)
+    return dict(items)[b'e']
+
+
+def pkdecrypt(keygrip, conn):
+    """Handle decryption using ECDH."""
+    for msg in [b'S INQUIRE_MAXLEN 4096', b'INQUIRE CIPHERTEXT']:
+        keyring.sendline(conn, msg)
+
+    line = keyring.recvline(conn)
+    assert keyring.recvline(conn) == b'END'
+    remote_pubkey = parse_ecdh(line)
+
+    keygrip_bytes = binascii.unhexlify(keygrip)
+    conn = open_connection(keygrip_bytes)
+    return _serialize_point(conn.ecdh(remote_pubkey))
+
+
+def handle_connection(conn):
+    """Handle connection from GPG binary using the ASSUAN protocol."""
+    keygrip = None
+    digest = None
+    algo = None
+    version = keyring.gpg_version()  # "Clone" existing GPG version
+
+    keyring.sendline(conn, b'OK')
+    for line in keyring.iterlines(conn):
+        parts = line.split(b' ')
+        command = parts[0]
+        args = parts[1:]
+        if command in {b'RESET', b'OPTION', b'HAVEKEY', b'SETKEYDESC'}:
+            pass  # reply with OK
+        elif command == b'GETINFO':
+            keyring.sendline(conn, b'D ' + version)
+        elif command == b'AGENT_ID':
+            keyring.sendline(conn, b'D TREZOR')  # "Fake" agent ID
+        elif command in {b'SIGKEY', b'SETKEY'}:
+            keygrip, = args
+        elif command == b'SETHASH':
+            algo, digest = args
+        elif command == b'PKSIGN':
+            sig = pksign(keygrip, digest, algo)
+            keyring.sendline(conn, b'D ' + sig)
+        elif command == b'PKDECRYPT':
+            sec = pkdecrypt(keygrip, conn)
+            keyring.sendline(conn, b'D ' + sec)
+        elif command == b'KEYINFO':
+            keygrip, = args
+            # Dummy reply (mainly for 'gpg --edit' to succeed).
+            # For details, see GnuPG agent KEYINFO command help.
+            fmt = 'S KEYINFO {0} X - - - - - - -'
+            keyring.sendline(conn, fmt.format(keygrip).encode('ascii'))
+        elif command == b'BYE':
+            return
+        elif command == b'KILLAGENT':
+            keyring.sendline(conn, b'OK')
+            raise StopIteration
+        else:
+            log.error('unknown request: %r', line)
+            return
+
+        keyring.sendline(conn, b'OK')

trezor_agent/gpg/client.py

@@ -0,0 +1,44 @@
+"""Device abstraction layer for GPG operations."""
+
+import logging
+
+from .. import device, formats, util
+
+log = logging.getLogger(__name__)
+
+
+class Client(object):
+    """Sign messages and get public keys from a hardware device."""
+
+    def __init__(self, user_id, curve_name):
+        """Connect to the device and retrieve required public key."""
+        self.device = device.detect()
+        self.user_id = user_id
+        self.identity = device.interface.Identity(
+            identity_str='gpg://', curve_name=curve_name)
+        self.identity.identity_dict['host'] = user_id
+
+    def pubkey(self, ecdh=False):
+        """Return public key as VerifyingKey object."""
+        with self.device:
+            pubkey = self.device.pubkey(ecdh=ecdh, identity=self.identity)
+        return formats.decompress_pubkey(
+            pubkey=pubkey, curve_name=self.identity.curve_name)
+
+    def sign(self, digest):
+        """Sign the digest and return a serialized signature."""
+        log.info('please confirm GPG signature on %s for "%s"...',
+                 self.device, self.user_id)
+        if self.identity.curve_name == formats.CURVE_NIST256:
+            digest = digest[:32]  # sign the first 256 bits
+        log.debug('signing digest: %s', util.hexlify(digest))
+        with self.device:
+            sig = self.device.sign(blob=digest, identity=self.identity)
+        return (util.bytes2num(sig[:32]), util.bytes2num(sig[32:]))
+
+    def ecdh(self, pubkey):
+        """Derive shared secret using ECDH from remote public key."""
+        log.info('please confirm GPG decryption on %s for "%s"...',
+                 self.device, self.user_id)
+        with self.device:
+            return self.device.ecdh(pubkey=pubkey, identity=self.identity)

trezor_agent/gpg/decode.py

@@ -0,0 +1,313 @@
+"""Decoders for GPG v2 data structures."""
+import base64
+import functools
+import hashlib
+import io
+import logging
+import struct
+
+import ecdsa
+import ed25519
+
+from . import protocol
+from .. import util
+
+log = logging.getLogger(__name__)
+
+
+def parse_subpackets(s):
+    """See https://tools.ietf.org/html/rfc4880#section-5.2.3.1 for details."""
+    subpackets = []
+    total_size = s.readfmt('>H')
+    data = s.read(total_size)
+    s = util.Reader(io.BytesIO(data))
+
+    while True:
+        try:
+            first = s.readfmt('B')
+        except EOFError:
+            break
+
+        if first < 192:
+            subpacket_len = first
+        elif first < 255:
+            subpacket_len = ((first - 192) << 8) + s.readfmt('B') + 192
+        else:  # first == 255
+            subpacket_len = s.readfmt('>L')
+
+        subpackets.append(s.read(subpacket_len))
+
+    return subpackets
+
+
+def parse_mpi(s):
+    """See https://tools.ietf.org/html/rfc4880#section-3.2 for details."""
+    bits = s.readfmt('>H')
+    blob = bytearray(s.read(int((bits + 7) // 8)))
+    return sum(v << (8 * i) for i, v in enumerate(reversed(blob)))
+
+
+def parse_mpis(s, n):
+    """Parse multiple MPIs from stream."""
+    return [parse_mpi(s) for _ in range(n)]
+
+
+def _parse_nist256p1_pubkey(mpi):
+    prefix, x, y = util.split_bits(mpi, 4, 256, 256)
+    assert prefix == 4
+    point = ecdsa.ellipticcurve.Point(curve=ecdsa.NIST256p.curve,
+                                      x=x, y=y)
+    return ecdsa.VerifyingKey.from_public_point(
+        point=point, curve=ecdsa.curves.NIST256p,
+        hashfunc=hashlib.sha256)
+
+
+def _parse_ed25519_pubkey(mpi):
+    prefix, value = util.split_bits(mpi, 8, 256)
+    assert prefix == 0x40
+    return ed25519.VerifyingKey(util.num2bytes(value, size=32))
+
+
+SUPPORTED_CURVES = {
+    b'\x2A\x86\x48\xCE\x3D\x03\x01\x07':
+        (_parse_nist256p1_pubkey, protocol.keygrip_nist256),
+    b'\x2B\x06\x01\x04\x01\xDA\x47\x0F\x01':
+        (_parse_ed25519_pubkey, protocol.keygrip_ed25519),
+    b'\x2B\x06\x01\x04\x01\x97\x55\x01\x05\x01':
+        (_parse_ed25519_pubkey, protocol.keygrip_curve25519),
+}
+
+RSA_ALGO_IDS = {1, 2, 3}
+ELGAMAL_ALGO_ID = 16
+DSA_ALGO_ID = 17
+ECDSA_ALGO_IDS = {18, 19, 22}  # {ecdsa, nist256, ed25519}
+
+
+def _parse_embedded_signatures(subpackets):
+    for packet in subpackets:
+        data = bytearray(packet)
+        if data[0] == 32:
+            # https://tools.ietf.org/html/rfc4880#section-5.2.3.26
+            stream = io.BytesIO(data[1:])
+            yield _parse_signature(util.Reader(stream))
+
+
+def has_custom_subpacket(signature_packet):
+    """Detect our custom public keys by matching subpacket data."""
+    return any(protocol.CUSTOM_KEY_LABEL == subpacket[1:]
+               for subpacket in signature_packet['unhashed_subpackets'])
+
+
+def _parse_signature(stream):
+    """See https://tools.ietf.org/html/rfc4880#section-5.2 for details."""
+    p = {'type': 'signature'}
+
+    to_hash = io.BytesIO()
+    with stream.capture(to_hash):
+        p['version'] = stream.readfmt('B')
+        p['sig_type'] = stream.readfmt('B')
+        p['pubkey_alg'] = stream.readfmt('B')
+        p['hash_alg'] = stream.readfmt('B')
+        p['hashed_subpackets'] = parse_subpackets(stream)
+
+    # https://tools.ietf.org/html/rfc4880#section-5.2.4
+    tail_to_hash = b'\x04\xff' + struct.pack('>L', to_hash.tell())
+
+    p['_to_hash'] = to_hash.getvalue() + tail_to_hash
+
+    p['unhashed_subpackets'] = parse_subpackets(stream)
+    embedded = list(_parse_embedded_signatures(p['unhashed_subpackets']))
+    if embedded:
+        log.debug('embedded sigs: %s', embedded)
+        p['embedded'] = embedded
+
+    p['hash_prefix'] = stream.readfmt('2s')
+    if p['pubkey_alg'] in ECDSA_ALGO_IDS:
+        p['sig'] = (parse_mpi(stream), parse_mpi(stream))
+    elif p['pubkey_alg'] in RSA_ALGO_IDS:  # RSA
+        p['sig'] = (parse_mpi(stream),)
+    elif p['pubkey_alg'] == DSA_ALGO_ID:
+        p['sig'] = (parse_mpi(stream), parse_mpi(stream))
+    else:
+        log.error('unsupported public key algo: %d', p['pubkey_alg'])
+
+    assert not stream.read()
+    return p
+
+
+def _parse_pubkey(stream, packet_type='pubkey'):
+    """See https://tools.ietf.org/html/rfc4880#section-5.5 for details."""
+    p = {'type': packet_type}
+    packet = io.BytesIO()
+    with stream.capture(packet):
+        p['version'] = stream.readfmt('B')
+        p['created'] = stream.readfmt('>L')
+        p['algo'] = stream.readfmt('B')
+        if p['algo'] in ECDSA_ALGO_IDS:
+            log.debug('parsing elliptic curve key')
+            # https://tools.ietf.org/html/rfc6637#section-11
+            oid_size = stream.readfmt('B')
+            oid = stream.read(oid_size)
+            assert oid in SUPPORTED_CURVES, util.hexlify(oid)
+            p['curve_oid'] = oid
+
+            mpi = parse_mpi(stream)
+            log.debug('mpi: %x (%d bits)', mpi, mpi.bit_length())
+            leftover = stream.read()
+            if leftover:
+                leftover = io.BytesIO(leftover)
+                # https://tools.ietf.org/html/rfc6637#section-8
+                # should be b'\x03\x01\x08\x07': SHA256 + AES128
+                size, = util.readfmt(leftover, 'B')
+                p['kdf'] = leftover.read(size)
+                p['secret'] = leftover.read()
+
+            parse_func, keygrip_func = SUPPORTED_CURVES[oid]
+            keygrip = keygrip_func(parse_func(mpi))
+            log.debug('keygrip: %s', util.hexlify(keygrip))
+            p['keygrip'] = keygrip
+
+        elif p['algo'] == DSA_ALGO_ID:
+            parse_mpis(stream, n=4)  # DSA keys are not supported
+        elif p['algo'] == ELGAMAL_ALGO_ID:
+            parse_mpis(stream, n=3)  # ElGamal keys are not supported
+        else:  # assume RSA
+            parse_mpis(stream, n=2)  # RSA keys are not supported
+        assert not stream.read()
+
+    # https://tools.ietf.org/html/rfc4880#section-12.2
+    packet_data = packet.getvalue()
+    data_to_hash = (b'\x99' + struct.pack('>H', len(packet_data)) +
+                    packet_data)
+    p['key_id'] = hashlib.sha1(data_to_hash).digest()[-8:]
+    p['_to_hash'] = data_to_hash
+    log.debug('key ID: %s', util.hexlify(p['key_id']))
+    return p
+
+_parse_subkey = functools.partial(_parse_pubkey, packet_type='subkey')
+
+
+def _parse_user_id(stream, packet_type='user_id'):
+    """See https://tools.ietf.org/html/rfc4880#section-5.11 for details."""
+    value = stream.read()
+    to_hash = b'\xb4' + util.prefix_len('>L', value)
+    return {'type': packet_type, 'value': value, '_to_hash': to_hash}
+
+# User attribute is handled as an opaque user ID
+_parse_attribute = functools.partial(_parse_user_id,
+                                     packet_type='user_attribute')
+
+PACKET_TYPES = {
+    2: _parse_signature,
+    5: _parse_pubkey,
+    6: _parse_pubkey,
+    7: _parse_subkey,
+    13: _parse_user_id,
+    14: _parse_subkey,
+    17: _parse_attribute,
+}
+
+
+def parse_packets(stream):
+    """
+    Support iterative parsing of available GPG packets.
+
+    See https://tools.ietf.org/html/rfc4880#section-4.2 for details.
+    """
+    reader = util.Reader(stream)
+    while True:
+        try:
+            value = reader.readfmt('B')
+        except EOFError:
+            return
+
+        log.debug('prefix byte: %s', bin(value))
+        assert util.bit(value, 7) == 1
+
+        tag = util.low_bits(value, 6)
+        if util.bit(value, 6) == 0:
+            length_type = util.low_bits(tag, 2)
+            tag = tag >> 2
+            fmt = {0: '>B', 1: '>H', 2: '>L'}[length_type]
+            packet_size = reader.readfmt(fmt)
+        else:
+            first = reader.readfmt('B')
+            if first < 192:
+                packet_size = first
+            elif first < 224:
+                packet_size = ((first - 192) << 8) + reader.readfmt('B') + 192
+            elif first == 255:
+                packet_size = reader.readfmt('>L')
+            else:
+                log.error('Partial Body Lengths unsupported')
+
+        log.debug('packet length: %d', packet_size)
+        packet_data = reader.read(packet_size)
+        packet_type = PACKET_TYPES.get(tag)
+
+        if packet_type is not None:
+            p = packet_type(util.Reader(io.BytesIO(packet_data)))
+            p['tag'] = tag
+        else:
+            p = {'type': 'unknown', 'tag': tag, 'raw': packet_data}
+
+        log.debug('packet "%s": %s', p['type'], p)
+        yield p
+
+
+def digest_packets(packets, hasher):
+    """Compute digest on specified packets, according to '_to_hash' field."""
+    data_to_hash = io.BytesIO()
+    for p in packets:
+        data_to_hash.write(p['_to_hash'])
+    hasher.update(data_to_hash.getvalue())
+    return hasher.digest()
+
+
+HASH_ALGORITHMS = {
+    1: 'md5',
+    2: 'sha1',
+    3: 'ripemd160',
+    8: 'sha256',
+    9: 'sha384',
+    10: 'sha512',
+    11: 'sha224',
+}
+
+
+def load_by_keygrip(pubkey_bytes, keygrip):
+    """Return public key and first user ID for specified keygrip."""
+    stream = io.BytesIO(pubkey_bytes)
+    packets = list(parse_packets(stream))
+    packets_per_pubkey = []
+    for p in packets:
+        if p['type'] == 'pubkey':
+            # Add a new packet list for each pubkey.
+            packets_per_pubkey.append([])
+        packets_per_pubkey[-1].append(p)
+
+    for packets in packets_per_pubkey:
+        user_ids = [p for p in packets if p['type'] == 'user_id']
+        for p in packets:
+            if p.get('keygrip') == keygrip:
+                return p, user_ids
+
+
+def load_signature(stream, original_data):
+    """Load signature from stream, and compute GPG digest for verification."""
+    signature, = list(parse_packets((stream)))
+    hash_alg = HASH_ALGORITHMS[signature['hash_alg']]
+    digest = digest_packets([{'_to_hash': original_data}, signature],
+                            hasher=hashlib.new(hash_alg))
+    assert signature['hash_prefix'] == digest[:2]
+    return signature, digest
+
+
+def remove_armor(armored_data):
+    """Decode armored data into its binary form."""
+    stream = io.BytesIO(armored_data)
+    lines = stream.readlines()[3:-1]
+    data = base64.b64decode(b''.join(lines))
+    payload, checksum = data[:-3], data[-3:]
+    assert util.crc24(payload) == checksum
+    return payload

trezor_agent/gpg/encode.py

@@ -0,0 +1,103 @@
+"""Create GPG ECDSA signatures and public keys using TREZOR device."""
+import io
+import logging
+
+from . import decode, keyring, protocol
+from .. import util
+
+log = logging.getLogger(__name__)
+
+
+def create_primary(user_id, pubkey, signer_func, secret_bytes=b''):
+    """Export new primary GPG public key, ready for "gpg2 --import"."""
+    pubkey_packet = protocol.packet(tag=(5 if secret_bytes else 6),
+                                    blob=(pubkey.data() + secret_bytes))
+    user_id_packet = protocol.packet(tag=13,
+                                     blob=user_id.encode('ascii'))
+
+    data_to_sign = (pubkey.data_to_hash() +
+                    user_id_packet[:1] +
+                    util.prefix_len('>L', user_id.encode('ascii')))
+    hashed_subpackets = [
+        protocol.subpacket_time(pubkey.created),  # signature time
+        # https://tools.ietf.org/html/rfc4880#section-5.2.3.7
+        protocol.subpacket_byte(0x0B, 9),  # preferred symmetric algo (AES-256)
+        # https://tools.ietf.org/html/rfc4880#section-5.2.3.4
+        protocol.subpacket_byte(0x1B, 1 | 2),  # key flags (certify & sign)
+        # https://tools.ietf.org/html/rfc4880#section-5.2.3.21
+        protocol.subpacket_byte(0x15, 8),  # preferred hash (SHA256)
+        # https://tools.ietf.org/html/rfc4880#section-5.2.3.8
+        protocol.subpacket_byte(0x16, 0),  # preferred compression (none)
+        # https://tools.ietf.org/html/rfc4880#section-5.2.3.9
+        protocol.subpacket_byte(0x17, 0x80)  # key server prefs (no-modify)
+        # https://tools.ietf.org/html/rfc4880#section-5.2.3.17
+    ]
+    unhashed_subpackets = [
+        protocol.subpacket(16, pubkey.key_id()),  # issuer key id
+        protocol.CUSTOM_SUBPACKET]
+
+    signature = protocol.make_signature(
+        signer_func=signer_func,
+        public_algo=pubkey.algo_id,
+        data_to_sign=data_to_sign,
+        sig_type=0x13,  # user id & public key
+        hashed_subpackets=hashed_subpackets,
+        unhashed_subpackets=unhashed_subpackets)
+
+    sign_packet = protocol.packet(tag=2, blob=signature)
+    return pubkey_packet + user_id_packet + sign_packet
+
+
+def create_subkey(primary_bytes, subkey, signer_func, secret_bytes=b''):
+    """Export new subkey to GPG primary key."""
+    subkey_packet = protocol.packet(tag=(7 if secret_bytes else 14),
+                                    blob=(subkey.data() + secret_bytes))
+    packets = list(decode.parse_packets(io.BytesIO(primary_bytes)))
+    primary, user_id, signature = packets[:3]
+
+    data_to_sign = primary['_to_hash'] + subkey.data_to_hash()
+
+    if subkey.ecdh:
+        embedded_sig = None
+    else:
+        # Primary Key Binding Signature
+        hashed_subpackets = [
+            protocol.subpacket_time(subkey.created)]  # signature time
+        unhashed_subpackets = [
+            protocol.subpacket(16, subkey.key_id())]  # issuer key id
+        embedded_sig = protocol.make_signature(
+            signer_func=signer_func,
+            data_to_sign=data_to_sign,
+            public_algo=subkey.algo_id,
+            sig_type=0x19,
+            hashed_subpackets=hashed_subpackets,
+            unhashed_subpackets=unhashed_subpackets)
+
+    # Subkey Binding Signature
+
+    # Key flags: https://tools.ietf.org/html/rfc4880#section-5.2.3.21
+    # (certify & sign)                   (encrypt)
+    flags = (2) if (not subkey.ecdh) else (4 | 8)
+
+    hashed_subpackets = [
+        protocol.subpacket_time(subkey.created),  # signature time
+        protocol.subpacket_byte(0x1B, flags)]
+
+    unhashed_subpackets = []
+    unhashed_subpackets.append(protocol.subpacket(16, primary['key_id']))
+    if embedded_sig is not None:
+        unhashed_subpackets.append(protocol.subpacket(32, embedded_sig))
+    unhashed_subpackets.append(protocol.CUSTOM_SUBPACKET)
+
+    if not decode.has_custom_subpacket(signature):
+        signer_func = keyring.create_agent_signer(user_id['value'])
+
+    signature = protocol.make_signature(
+        signer_func=signer_func,
+        data_to_sign=data_to_sign,
+        public_algo=primary['algo'],
+        sig_type=0x18,
+        hashed_subpackets=hashed_subpackets,
+        unhashed_subpackets=unhashed_subpackets)
+    sign_packet = protocol.packet(tag=2, blob=signature)
+    return primary_bytes + subkey_packet + sign_packet

trezor_agent/gpg/keyring.py

@@ -0,0 +1,229 @@
+"""Tools for doing signature using gpg-agent."""
+from __future__ import absolute_import, print_function, unicode_literals
+
+import binascii
+import io
+import logging
+import os
+import re
+import socket
+import subprocess
+
+from .. import util
+
+log = logging.getLogger(__name__)
+
+
+def get_agent_sock_path(sp=subprocess):
+    """Parse gpgconf output to find out GPG agent UNIX socket path."""
+    lines = sp.check_output(['gpgconf', '--list-dirs']).strip().split(b'\n')
+    dirs = dict(line.split(b':', 1) for line in lines)
+    return dirs[b'agent-socket']
+
+
+def connect_to_agent(sp=subprocess):
+    """Connect to GPG agent's UNIX socket."""
+    sock_path = get_agent_sock_path(sp=sp)
+    sp.check_call(['gpg-connect-agent', '/bye'])  # Make sure it's running
+    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+    sock.connect(sock_path)
+    return sock
+
+
+def communicate(sock, msg):
+    """Send a message and receive a single line."""
+    sendline(sock, msg.encode('ascii'))
+    return recvline(sock)
+
+
+def sendline(sock, msg):
+    """Send a binary message, followed by EOL."""
+    log.debug('<- %r', msg)
+    sock.sendall(msg + b'\n')
+
+
+def recvline(sock):
+    """Receive a single line from the socket."""
+    reply = io.BytesIO()
+
+    while True:
+        c = sock.recv(1)
+        if not c:
+            return None  # socket is closed
+
+        if c == b'\n':
+            break
+        reply.write(c)
+
+    result = reply.getvalue()
+    log.debug('-> %r', result)
+    return result
+
+
+def iterlines(conn):
+    """Iterate over input, split by lines."""
+    while True:
+        line = recvline(conn)
+        if line is None:
+            break
+        yield line
+
+
+def unescape(s):
+    """Unescape ASSUAN message (0xAB <-> '%AB')."""
+    s = bytearray(s)
+    i = 0
+    while i < len(s):
+        if s[i] == ord('%'):
+            hex_bytes = bytes(s[i+1:i+3])
+            value = int(hex_bytes.decode('ascii'), 16)
+            s[i:i+3] = [value]
+        i += 1
+    return bytes(s)
+
+
+def parse_term(s):
+    """Parse single s-expr term from bytes."""
+    size, s = s.split(b':', 1)
+    size = int(size)
+    return s[:size], s[size:]
+
+
+def parse(s):
+    """Parse full s-expr from bytes."""
+    if s.startswith(b'('):
+        s = s[1:]
+        name, s = parse_term(s)
+        values = [name]
+        while not s.startswith(b')'):
+            value, s = parse(s)
+            values.append(value)
+        return values, s[1:]
+    else:
+        return parse_term(s)
+
+
+def _parse_ecdsa_sig(args):
+    (r, sig_r), (s, sig_s) = args
+    assert r == b'r'
+    assert s == b's'
+    return (util.bytes2num(sig_r),
+            util.bytes2num(sig_s))
+
+# DSA and EDDSA happen to have the same structure as ECDSA signatures
+_parse_dsa_sig = _parse_ecdsa_sig
+_parse_eddsa_sig = _parse_ecdsa_sig
+
+
+def _parse_rsa_sig(args):
+    (s, sig_s), = args
+    assert s == b's'
+    return (util.bytes2num(sig_s),)
+
+
+def parse_sig(sig):
+    """Parse signature integer values from s-expr."""
+    label, sig = sig
+    assert label == b'sig-val'
+    algo_name = sig[0]
+    parser = {b'rsa': _parse_rsa_sig,
+              b'ecdsa': _parse_ecdsa_sig,
+              b'eddsa': _parse_eddsa_sig,
+              b'dsa': _parse_dsa_sig}[algo_name]
+    return parser(args=sig[1:])
+
+
+def sign_digest(sock, keygrip, digest, sp=subprocess, environ=None):
+    """Sign a digest using specified key using GPG agent."""
+    hash_algo = 8  # SHA256
+    assert len(digest) == 32
+
+    assert communicate(sock, 'RESET').startswith(b'OK')
+
+    ttyname = sp.check_output(['tty']).strip()
+    options = ['ttyname={}'.format(ttyname)]  # set TTY for passphrase entry
+
+    display = (environ or os.environ).get('DISPLAY')
+    if display is not None:
+        options.append('display={}'.format(display))
+
+    for opt in options:
+        assert communicate(sock, 'OPTION {}'.format(opt)) == b'OK'
+
+    assert communicate(sock, 'SIGKEY {}'.format(keygrip)) == b'OK'
+    hex_digest = binascii.hexlify(digest).upper().decode('ascii')
+    assert communicate(sock, 'SETHASH {} {}'.format(hash_algo,
+                                                    hex_digest)) == b'OK'
+
+    assert communicate(sock, 'SETKEYDESC '
+                       'Sign+a+new+TREZOR-based+subkey') == b'OK'
+    assert communicate(sock, 'PKSIGN') == b'OK'
+    while True:
+        line = recvline(sock).strip()
+        if line.startswith(b'S PROGRESS'):
+            continue
+        else:
+            break
+    line = unescape(line)
+    log.debug('unescaped: %r', line)
+    prefix, sig = line.split(b' ', 1)
+    if prefix != b'D':
+        raise ValueError(prefix)
+
+    sig, leftover = parse(sig)
+    assert not leftover, leftover
+    return parse_sig(sig)
+
+
+def gpg_command(args, env=None):
+    """Prepare common GPG command line arguments."""
+    if env is None:
+        env = os.environ
+    cmd = ['gpg2']
+    homedir = env.get('GNUPGHOME')
+    if homedir:
+        cmd.extend(['--homedir', homedir])
+    return cmd + args
+
+
+def get_keygrip(user_id, sp=subprocess):
+    """Get a keygrip of the primary GPG key of the specified user."""
+    args = gpg_command(['--list-keys', '--with-keygrip', user_id])
+    output = sp.check_output(args).decode('ascii')
+    return re.findall(r'Keygrip = (\w+)', output)[0]
+
+
+def gpg_version(sp=subprocess):
+    """Get a keygrip of the primary GPG key of the specified user."""
+    args = gpg_command(['--version'])
+    output = sp.check_output(args)
+    line = output.split(b'\n')[0]  # b'gpg (GnuPG) 2.1.11'
+    return line.split(b' ')[-1]  # b'2.1.11'
+
+
+def export_public_key(user_id, sp=subprocess):
+    """Export GPG public key for specified `user_id`."""
+    args = gpg_command(['--export', user_id])
+    result = sp.check_output(args=args)
+    if not result:
+        log.error('could not find public key %r in local GPG keyring', user_id)
+        raise KeyError(user_id)
+    return result
+
+
+def export_public_keys(sp=subprocess):
+    """Export all GPG public keys."""
+    args = gpg_command(['--export'])
+    return sp.check_output(args=args)
+
+
+def create_agent_signer(user_id):
+    """Sign digest with existing GPG keys using gpg-agent tool."""
+    sock = connect_to_agent()
+    keygrip = get_keygrip(user_id)
+
+    def sign(digest):
+        """Sign the digest and return an ECDSA/RSA/DSA signature."""
+        return sign_digest(sock=sock, keygrip=keygrip, digest=digest)
+
+    return sign

trezor_agent/gpg/protocol.py

@@ -0,0 +1,271 @@
+"""GPG protocol utilities."""
+
+import base64
+import hashlib
+import logging
+import struct
+
+from .. import formats, util
+
+log = logging.getLogger(__name__)
+
+
+def packet(tag, blob):
+    """Create small GPG packet."""
+    assert len(blob) < 2**32
+
+    if len(blob) < 2**8:
+        length_type = 0
+    elif len(blob) < 2**16:
+        length_type = 1
+    else:
+        length_type = 2
+
+    fmt = ['>B', '>H', '>L'][length_type]
+    leading_byte = 0x80 | (tag << 2) | (length_type)
+    return struct.pack('>B', leading_byte) + util.prefix_len(fmt, blob)
+
+
+def subpacket(subpacket_type, fmt, *values):
+    """Create GPG subpacket."""
+    blob = struct.pack(fmt, *values) if values else fmt
+    return struct.pack('>B', subpacket_type) + blob
+
+
+def subpacket_long(subpacket_type, value):
+    """Create GPG subpacket with 32-bit unsigned integer."""
+    return subpacket(subpacket_type, '>L', value)
+
+
+def subpacket_time(value):
+    """Create GPG subpacket with time in seconds (since Epoch)."""
+    return subpacket_long(2, value)
+
+
+def subpacket_byte(subpacket_type, value):
+    """Create GPG subpacket with 8-bit unsigned integer."""
+    return subpacket(subpacket_type, '>B', value)
+
+
+def subpacket_prefix_len(item):
+    """Prefix subpacket length according to RFC 4880 section-5.2.3.1."""
+    n = len(item)
+    if n >= 8384:
+        prefix = b'\xFF' + struct.pack('>L', n)
+    elif n >= 192:
+        n = n - 192
+        prefix = struct.pack('BB', (n // 256) + 192, n % 256)
+    else:
+        prefix = struct.pack('B', n)
+    return prefix + item
+
+
+def subpackets(*items):
+    """Serialize several GPG subpackets."""
+    prefixed = [subpacket_prefix_len(item) for item in items]
+    return util.prefix_len('>H', b''.join(prefixed))
+
+
+def mpi(value):
+    """Serialize multipresicion integer using GPG format."""
+    bits = value.bit_length()
+    data_size = (bits + 7) // 8
+    data_bytes = bytearray(data_size)
+    for i in range(data_size):
+        data_bytes[i] = value & 0xFF
+        value = value >> 8
+
+    data_bytes.reverse()
+    return struct.pack('>H', bits) + bytes(data_bytes)
+
+
+def _serialize_nist256(vk):
+    return mpi((4 << 512) |
+               (vk.pubkey.point.x() << 256) |
+               (vk.pubkey.point.y()))
+
+
+def _serialize_ed25519(vk):
+    return mpi((0x40 << 256) |
+               util.bytes2num(vk.to_bytes()))
+
+
+def _compute_keygrip(params):
+    parts = []
+    for name, value in params:
+        exp = '{}:{}{}:'.format(len(name), name, len(value))
+        parts.append(b'(' + exp.encode('ascii') + value + b')')
+
+    return hashlib.sha1(b''.join(parts)).digest()
+
+
+def keygrip_nist256(vk):
+    """Compute keygrip for NIST256 curve public keys."""
+    curve = vk.curve.curve
+    gen = vk.curve.generator
+    g = (4 << 512) | (gen.x() << 256) | gen.y()
+    point = vk.pubkey.point
+    q = (4 << 512) | (point.x() << 256) | point.y()
+
+    return _compute_keygrip([
+        ['p', util.num2bytes(curve.p(), size=32)],
+        ['a', util.num2bytes(curve.a() % curve.p(), size=32)],
+        ['b', util.num2bytes(curve.b() % curve.p(), size=32)],
+        ['g', util.num2bytes(g, size=65)],
+        ['n', util.num2bytes(vk.curve.order, size=32)],
+        ['q', util.num2bytes(q, size=65)],
+    ])
+
+
+def keygrip_ed25519(vk):
+    """Compute keygrip for Ed25519 public keys."""
+    # pylint: disable=line-too-long
+    return _compute_keygrip([
+        ['p', util.num2bytes(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFED, size=32)],  # nopep8
+        ['a', b'\x01'],
+        ['b', util.num2bytes(0x2DFC9311D490018C7338BF8688861767FF8FF5B2BEBE27548A14B235ECA6874A, size=32)],  # nopep8
+        ['g', util.num2bytes(0x04216936D3CD6E53FEC0A4E231FDD6DC5C692CC7609525A7B2C9562D608F25D51A6666666666666666666666666666666666666666666666666666666666666658, size=65)],  # nopep8
+        ['n', util.num2bytes(0x1000000000000000000000000000000014DEF9DEA2F79CD65812631A5CF5D3ED, size=32)],  # nopep8
+        ['q', vk.to_bytes()],
+    ])
+
+
+def keygrip_curve25519(vk):
+    """Compute keygrip for Curve25519 public keys."""
+    # pylint: disable=line-too-long
+    return _compute_keygrip([
+        ['p', util.num2bytes(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFED, size=32)],  # nopep8
+        ['a', b'\x01\xDB\x41'],
+        ['b', b'\x01'],
+        ['g', util.num2bytes(0x04000000000000000000000000000000000000000000000000000000000000000920ae19a1b8a086b4e01edd2c7748d14c923d4d7e6d7c61b229e9c5a27eced3d9, size=65)],  # nopep8
+        ['n', util.num2bytes(0x1000000000000000000000000000000014DEF9DEA2F79CD65812631A5CF5D3ED, size=32)],  # nopep8
+        ['q', vk.to_bytes()],
+    ])
+
+
+SUPPORTED_CURVES = {
+    formats.CURVE_NIST256: {
+        # https://tools.ietf.org/html/rfc6637#section-11
+        'oid': b'\x2A\x86\x48\xCE\x3D\x03\x01\x07',
+        'algo_id': 19,
+        'serialize': _serialize_nist256,
+        'keygrip': keygrip_nist256,
+    },
+    formats.CURVE_ED25519: {
+        'oid': b'\x2B\x06\x01\x04\x01\xDA\x47\x0F\x01',
+        'algo_id': 22,
+        'serialize': _serialize_ed25519,
+        'keygrip': keygrip_ed25519,
+    },
+    formats.ECDH_CURVE25519: {
+        'oid': b'\x2B\x06\x01\x04\x01\x97\x55\x01\x05\x01',
+        'algo_id': 18,
+        'serialize': _serialize_ed25519,
+        'keygrip': keygrip_curve25519,
+    },
+}
+
+ECDH_ALGO_ID = 18
+
+CUSTOM_KEY_LABEL = b'TREZOR-GPG'  # marks "our" pubkey
+CUSTOM_SUBPACKET_ID = 26  # use "policy URL" subpacket
+CUSTOM_SUBPACKET = subpacket(CUSTOM_SUBPACKET_ID, CUSTOM_KEY_LABEL)
+
+
+def get_curve_name_by_oid(oid):
+    """Return curve name matching specified OID, or raise KeyError."""
+    for curve_name, info in SUPPORTED_CURVES.items():
+        if info['oid'] == oid:
+            return curve_name
+    raise KeyError('Unknown OID: {!r}'.format(oid))
+
+
+class PublicKey(object):
+    """GPG representation for public key packets."""
+
+    def __init__(self, curve_name, created, verifying_key, ecdh=False):
+        """Contruct using a ECDSA VerifyingKey object."""
+        self.curve_name = curve_name
+        self.curve_info = SUPPORTED_CURVES[curve_name]
+        self.created = int(created)  # time since Epoch
+        self.verifying_key = verifying_key
+        self.ecdh = bool(ecdh)
+        if ecdh:
+            self.algo_id = ECDH_ALGO_ID
+            self.ecdh_packet = b'\x03\x01\x08\x07'
+        else:
+            self.algo_id = self.curve_info['algo_id']
+            self.ecdh_packet = b''
+
+    def keygrip(self):
+        """Compute GPG keygrip of the verifying key."""
+        return self.curve_info['keygrip'](self.verifying_key)
+
+    def data(self):
+        """Data for packet creation."""
+        header = struct.pack('>BLB',
+                             4,             # version
+                             self.created,  # creation
+                             self.algo_id)  # public key algorithm ID
+        oid = util.prefix_len('>B', self.curve_info['oid'])
+        blob = self.curve_info['serialize'](self.verifying_key)
+        return header + oid + blob + self.ecdh_packet
+
+    def data_to_hash(self):
+        """Data for digest computation."""
+        return b'\x99' + util.prefix_len('>H', self.data())
+
+    def _fingerprint(self):
+        return hashlib.sha1(self.data_to_hash()).digest()
+
+    def key_id(self):
+        """Short (8 byte) GPG key ID."""
+        return self._fingerprint()[-8:]
+
+    def __repr__(self):
+        """Short (8 hexadecimal digits) GPG key ID."""
+        hex_key_id = util.hexlify(self.key_id())[-8:]
+        return 'GPG public key {}/{}'.format(self.curve_name, hex_key_id)
+
+    __str__ = __repr__
+
+
+def _split_lines(body, size):
+    lines = []
+    for i in range(0, len(body), size):
+        lines.append(body[i:i+size] + '\n')
+    return ''.join(lines)
+
+
+def armor(blob, type_str):
+    """See https://tools.ietf.org/html/rfc4880#section-6 for details."""
+    head = '-----BEGIN PGP {}-----\nVersion: GnuPG v2\n\n'.format(type_str)
+    body = base64.b64encode(blob).decode('ascii')
+    checksum = base64.b64encode(util.crc24(blob)).decode('ascii')
+    tail = '-----END PGP {}-----\n'.format(type_str)
+    return head + _split_lines(body, 64) + '=' + checksum + '\n' + tail
+
+
+def make_signature(signer_func, data_to_sign, public_algo,
+                   hashed_subpackets, unhashed_subpackets, sig_type=0):
+    """Create new GPG signature."""
+    # pylint: disable=too-many-arguments
+    header = struct.pack('>BBBB',
+                         4,         # version
+                         sig_type,  # rfc4880 (section-5.2.1)
+                         public_algo,
+                         8)         # hash_alg (SHA256)
+    hashed = subpackets(*hashed_subpackets)
+    unhashed = subpackets(*unhashed_subpackets)
+    tail = b'\x04\xff' + struct.pack('>L', len(header) + len(hashed))
+    data_to_hash = data_to_sign + header + hashed + tail
+
+    log.debug('hashing %d bytes', len(data_to_hash))
+    digest = hashlib.sha256(data_to_hash).digest()
+    log.debug('signing digest: %s', util.hexlify(digest))
+    params = signer_func(digest=digest)
+    sig = b''.join(mpi(p) for p in params)
+
+    return bytes(header + hashed + unhashed +
+                 digest[:2] +  # used for decoder's sanity check
+                 sig)  # actual ECDSA signature

trezor_agent/gpg/tests/__init__.py

@@ -0,0 +1 @@
+"""Tests for GPG module."""

trezor_agent/gpg/tests/test_decode.py

@@ -0,0 +1,58 @@
+import glob
+import io
+import os
+
+import pytest
+
+from .. import decode, protocol
+from ... import util
+
+
+def test_subpackets():
+    s = io.BytesIO(b'\x00\x05\x02\xAB\xCD\x01\xEF')
+    assert decode.parse_subpackets(util.Reader(s)) == [b'\xAB\xCD', b'\xEF']
+
+
+def test_subpackets_prefix():
+    for n in [0, 1, 2, 4, 5, 10, 191, 192, 193,
+              255, 256, 257, 8383, 8384, 65530]:
+        item = b'?' * n  # create dummy subpacket
+        prefixed = protocol.subpackets(item)
+        result = decode.parse_subpackets(util.Reader(io.BytesIO(prefixed)))
+        assert [item] == result
+
+
+def test_mpi():
+    s = io.BytesIO(b'\x00\x09\x01\x23')
+    assert decode.parse_mpi(util.Reader(s)) == 0x123
+
+    s = io.BytesIO(b'\x00\x09\x01\x23\x00\x03\x05')
+    assert decode.parse_mpis(util.Reader(s), n=2) == [0x123, 5]
+
+
+cwd = os.path.join(os.path.dirname(__file__))
+input_files = glob.glob(os.path.join(cwd, '*.gpg'))
+
+
+@pytest.fixture(params=input_files)
+def public_key_path(request):
+    return request.param
+
+
+def test_gpg_files(public_key_path):  # pylint: disable=redefined-outer-name
+    with open(public_key_path, 'rb') as f:
+        packets = list(decode.parse_packets(f))
+        assert len(packets) > 0
+
+
+def test_has_custom_subpacket():
+    sig = {'unhashed_subpackets': []}
+    assert not decode.has_custom_subpacket(sig)
+
+    custom_markers = [
+        protocol.CUSTOM_SUBPACKET,
+        protocol.subpacket(10, protocol.CUSTOM_KEY_LABEL),
+    ]
+    for marker in custom_markers:
+        sig = {'unhashed_subpackets': [marker]}
+        assert decode.has_custom_subpacket(sig)

trezor_agent/gpg/tests/test_keyring.py

@@ -0,0 +1,101 @@
+import io
+
+import mock
+
+from .. import keyring
+
+
+def test_unescape_short():
+    assert keyring.unescape(b'abc%0AX%0D %25;.-+()') == b'abc\nX\r %;.-+()'
+
+
+def test_unescape_long():
+    escaped = (b'D (7:sig-val(3:dsa(1:r32:\x1d\x15.\x12\xe8h\x19\xd9O\xeb\x06'
+               b'yD?a:/\xae\xdb\xac\x93\xa6\x86\xcbs\xb8\x03\xf1\xcb\x89\xc7'
+               b'\x1f)(1:s32:%25\xb5\x04\x94\xc7\xc4X\xc7\xe0%0D\x08\xbb%0DuN'
+               b'\x9c6}[\xc2=t\x8c\xfdD\x81\xe8\xdd\x86=\xe2\xa9)))')
+    unescaped = (b'D (7:sig-val(3:dsa(1:r32:\x1d\x15.\x12\xe8h\x19\xd9O\xeb'
+                 b'\x06yD?a:/\xae\xdb\xac\x93\xa6\x86\xcbs\xb8\x03\xf1\xcb\x89'
+                 b'\xc7\x1f)(1:s32:%\xb5\x04\x94\xc7\xc4X\xc7\xe0\r\x08\xbb\ru'
+                 b'N\x9c6}[\xc2=t\x8c\xfdD\x81\xe8\xdd\x86=\xe2\xa9)))')
+    assert keyring.unescape(escaped) == unescaped
+
+
+def test_parse_term():
+    assert keyring.parse(b'4:abcdXXX') == (b'abcd', b'XXX')
+
+
+def test_parse_ecdsa():
+    sig, rest = keyring.parse(b'(7:sig-val(5:ecdsa'
+                              b'(1:r2:\x01\x02)(1:s2:\x03\x04)))')
+    values = [[b'r', b'\x01\x02'], [b's', b'\x03\x04']]
+    assert sig == [b'sig-val', [b'ecdsa'] + values]
+    assert rest == b''
+    assert keyring.parse_sig(sig) == (0x102, 0x304)
+
+
+def test_parse_rsa():
+    sig, rest = keyring.parse(b'(7:sig-val(3:rsa(1:s4:\x01\x02\x03\x04)))')
+    assert sig == [b'sig-val', [b'rsa', [b's', b'\x01\x02\x03\x04']]]
+    assert rest == b''
+    assert keyring.parse_sig(sig) == (0x1020304,)
+
+
+class FakeSocket(object):
+    def __init__(self):
+        self.rx = io.BytesIO()
+        self.tx = io.BytesIO()
+
+    def recv(self, n):
+        return self.rx.read(n)
+
+    def sendall(self, data):
+        self.tx.write(data)
+
+
+def test_sign_digest():
+    sock = FakeSocket()
+    sock.rx.write(b'OK Pleased to meet you, process XYZ\n')
+    sock.rx.write(b'OK\n' * 6)
+    sock.rx.write(b'D (7:sig-val(3:rsa(1:s16:0123456789ABCDEF)))\n')
+    sock.rx.seek(0)
+    keygrip = '1234'
+    digest = b'A' * 32
+    sp = mock.Mock(spec=['check_output'])
+    sp.check_output.return_value = '/dev/pts/0'
+    sig = keyring.sign_digest(sock=sock, keygrip=keygrip,
+                              digest=digest, sp=sp,
+                              environ={'DISPLAY': ':0'})
+    assert sig == (0x30313233343536373839414243444546,)
+    assert sock.tx.getvalue() == b'''RESET
+OPTION ttyname=/dev/pts/0
+OPTION display=:0
+SIGKEY 1234
+SETHASH 8 4141414141414141414141414141414141414141414141414141414141414141
+SETKEYDESC Sign+a+new+TREZOR-based+subkey
+PKSIGN
+'''
+
+
+def test_iterlines():
+    sock = FakeSocket()
+    sock.rx.write(b'foo\nbar\nxyz')
+    sock.rx.seek(0)
+    assert list(keyring.iterlines(sock)) == [b'foo', b'bar']
+
+
+def test_get_agent_sock_path():
+    sp = mock.Mock(spec=['check_output'])
+    sp.check_output.return_value = b'''sysconfdir:/usr/local/etc/gnupg
+bindir:/usr/local/bin
+libexecdir:/usr/local/libexec
+libdir:/usr/local/lib/gnupg
+datadir:/usr/local/share/gnupg
+localedir:/usr/local/share/locale
+dirmngr-socket:/run/user/1000/gnupg/S.dirmngr
+agent-ssh-socket:/run/user/1000/gnupg/S.gpg-agent.ssh
+agent-socket:/run/user/1000/gnupg/S.gpg-agent
+homedir:/home/roman/.gnupg
+'''
+    expected = b'/run/user/1000/gnupg/S.gpg-agent'
+    assert keyring.get_agent_sock_path(sp=sp) == expected

trezor_agent/gpg/tests/test_protocol.py

@@ -0,0 +1,107 @@
+import ecdsa
+import ed25519
+import pytest
+
+from .. import protocol
+from ... import formats
+
+
+def test_packet():
+    assert protocol.packet(1, b'') == b'\x84\x00'
+    assert protocol.packet(2, b'A') == b'\x88\x01A'
+    blob = b'B' * 0xAB
+    assert protocol.packet(3, blob) == b'\x8c\xAB' + blob
+    blob = b'C' * 0x1234
+    assert protocol.packet(3, blob) == b'\x8d\x12\x34' + blob
+    blob = b'D' * 0x12345678
+    assert protocol.packet(4, blob) == b'\x92\x12\x34\x56\x78' + blob
+
+
+def test_subpackets():
+    assert protocol.subpacket(1, b'') == b'\x01'
+    assert protocol.subpacket(2, '>H', 0x0304) == b'\x02\x03\x04'
+    assert protocol.subpacket_long(9, 0x12345678) == b'\x09\x12\x34\x56\x78'
+    assert protocol.subpacket_time(0x12345678) == b'\x02\x12\x34\x56\x78'
+    assert protocol.subpacket_byte(0xAB, 0xCD) == b'\xAB\xCD'
+    assert protocol.subpackets() == b'\x00\x00'
+    assert protocol.subpackets(b'ABC', b'12345') == b'\x00\x0A\x03ABC\x0512345'
+
+
+def test_mpi():
+    assert protocol.mpi(0x123) == b'\x00\x09\x01\x23'
+
+
+def test_armor():
+    data = bytearray(range(256))
+    assert protocol.armor(data, 'TEST') == '''-----BEGIN PGP TEST-----
+Version: GnuPG v2
+
+AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8gISIjJCUmJygpKissLS4v
+MDEyMzQ1Njc4OTo7PD0+P0BBQkNERUZHSElKS0xNTk9QUVJTVFVWV1hZWltcXV5f
+YGFiY2RlZmdoaWprbG1ub3BxcnN0dXZ3eHl6e3x9fn+AgYKDhIWGh4iJiouMjY6P
+kJGSk5SVlpeYmZqbnJ2en6ChoqOkpaanqKmqq6ytrq+wsbKztLW2t7i5uru8vb6/
+wMHCw8TFxsfIycrLzM3Oz9DR0tPU1dbX2Nna29zd3t/g4eLj5OXm5+jp6uvs7e7v
+8PHy8/T19vf4+fr7/P3+/w==
+=W700
+-----END PGP TEST-----
+'''
+
+
+def test_make_signature():
+    def signer_func(digest):
+        assert digest == (b'\xd0\xe5]|\x8bP\xe6\x91\xb3\xe8+\xf4A\xf0`(\xb1'
+                          b'\xc7\xf4;\x86\x97s\xdb\x9a\xda\xee< \xcb\x9e\x00')
+        return (7, 8)
+
+    sig = protocol.make_signature(
+        signer_func=signer_func,
+        data_to_sign=b'Hello World!',
+        public_algo=22,
+        hashed_subpackets=[protocol.subpacket_time(1)],
+        unhashed_subpackets=[],
+        sig_type=25)
+    assert sig == (b'\x04\x19\x16\x08\x00\x06\x05\x02'
+                   b'\x00\x00\x00\x01\x00\x00\xd0\xe5\x00\x03\x07\x00\x04\x08')
+
+
+def test_nist256p1():
+    sk = ecdsa.SigningKey.from_secret_exponent(secexp=1, curve=ecdsa.NIST256p)
+    vk = sk.get_verifying_key()
+    pk = protocol.PublicKey(curve_name=formats.CURVE_NIST256,
+                            created=42, verifying_key=vk)
+    assert repr(pk) == 'GPG public key nist256p1/F82361D9'
+    assert pk.keygrip() == b'\x95\x85.\x91\x7f\xe2\xc3\x91R\xba\x99\x81\x92\xb5y\x1d\xb1\\\xdc\xf0'
+
+
+def test_nist256p1_ecdh():
+    sk = ecdsa.SigningKey.from_secret_exponent(secexp=1, curve=ecdsa.NIST256p)
+    vk = sk.get_verifying_key()
+    pk = protocol.PublicKey(curve_name=formats.CURVE_NIST256,
+                            created=42, verifying_key=vk, ecdh=True)
+    assert repr(pk) == 'GPG public key nist256p1/5811DF46'
+    assert pk.keygrip() == b'\x95\x85.\x91\x7f\xe2\xc3\x91R\xba\x99\x81\x92\xb5y\x1d\xb1\\\xdc\xf0'
+
+
+def test_ed25519():
+    sk = ed25519.SigningKey(b'\x00' * 32)
+    vk = sk.get_verifying_key()
+    pk = protocol.PublicKey(curve_name=formats.CURVE_ED25519,
+                            created=42, verifying_key=vk)
+    assert repr(pk) == 'GPG public key ed25519/36B40FE6'
+    assert pk.keygrip() == b'\xbf\x01\x90l\x17\xb64\xa3-\xf4\xc0gr\x99\x18<\xddBQ?'
+
+
+def test_curve25519():
+    sk = ed25519.SigningKey(b'\x00' * 32)
+    vk = sk.get_verifying_key()
+    pk = protocol.PublicKey(curve_name=formats.ECDH_CURVE25519,
+                            created=42, verifying_key=vk)
+    assert repr(pk) == 'GPG public key curve25519/69460384'
+    assert pk.keygrip() == b'x\xd6\x86\xe4\xa6\xfc;\x0fY\xe1}Lw\xc4\x9ed\xf1Q\x8a\x00'
+
+
+def test_get_curve_name_by_oid():
+    for name, info in protocol.SUPPORTED_CURVES.items():
+        assert protocol.get_curve_name_by_oid(info['oid']) == name
+    with pytest.raises(KeyError):
+        protocol.get_curve_name_by_oid('BAD_OID')

trezor_agent/protocol.py

@@ -7,7 +7,6 @@ for more details.
 The server's source code can be found here:
 https://github.com/openssh/openssh-portable/blob/master/authfd.c
 """
-import binascii
 import io
 import logging
 
@@ -122,7 +121,7 @@ class Handler(object):
         SSH v2 public key authentication is performed.
 
         If the required key is not supported, raise KeyError
-        If the signature is invalid, rause ValueError
+        If the signature is invalid, raise ValueError
         """
         key = formats.parse_pubkey(util.read_frame(buf))
         log.debug('looking for %s', key['fingerprint'])
@@ -138,13 +137,13 @@ class Handler(object):
         else:
             raise KeyError('key not found')
 
-        log.debug('signing %d-byte blob', len(blob))
         label = key['name'].decode('ascii')  # label should be a string
+        log.debug('signing %d-byte blob with "%s" key', len(blob), label)
         try:
-            signature = self.signer(label=label, blob=blob)
+            signature = self.signer(blob=blob, identity=key['identity'])
         except IOError:
             return failure()
-        log.debug('signature: %s', binascii.hexlify(signature))
+        log.debug('signature: %r', signature)
 
         try:
             sig_bytes = key['verifier'](sig=signature, msg=blob)

trezor_agent/server.py

@@ -1,5 +1,6 @@
 """UNIX-domain socket server for ssh-agent implementation."""
 import contextlib
+import functools
 import logging
 import os
 import socket
@@ -30,7 +31,7 @@ def unix_domain_socket_server(sock_path):
 
     Listen on it, and delete it after the generated context is over.
     """
-    log.debug('serving on SSH_AUTH_SOCK=%s', sock_path)
+    log.debug('serving on %s', sock_path)
     remove_file(sock_path)
 
     server = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
@@ -42,19 +43,24 @@ def unix_domain_socket_server(sock_path):
         remove_file(sock_path)
 
 
-def handle_connection(conn, handler):
+def handle_connection(conn, handler, mutex):
     """
     Handle a single connection using the specified protocol handler in a loop.
 
+    Since this function may be called concurrently from server_thread,
+    the specified mutex is used to synchronize the device handling.
+
     Exit when EOFError is raised.
     All other exceptions are logged as warnings.
     """
     try:
         log.debug('welcome agent')
-        while True:
-            msg = util.read_frame(conn)
-            reply = handler.handle(msg=msg)
-            util.send(conn, reply)
+        with contextlib.closing(conn):
+            while True:
+                msg = util.read_frame(conn)
+                with mutex:
+                    reply = handler.handle(msg=msg)
+                util.send(conn, reply)
     except EOFError:
         log.debug('goodbye agent')
     except Exception as e:  # pylint: disable=broad-except
@@ -77,7 +83,7 @@ def retry(func, exception_type, quit_event):
             pass
 
 
-def server_thread(sock, handler, quit_event):
+def server_thread(sock, handle_conn, quit_event):
     """Run a server on the specified socket."""
     log.debug('server thread started')
 
@@ -93,8 +99,9 @@ def server_thread(sock, handler, quit_event):
         except StopIteration:
             log.debug('server stopped')
             break
-        with contextlib.closing(conn):
-            handle_connection(conn, handler)
+        # Handle connections from SSH concurrently.
+        threading.Thread(target=handle_conn,
+                         kwargs=dict(conn=conn)).start()
     log.debug('server thread stopped')
 
 
@@ -115,14 +122,23 @@ def serve(handler, sock_path=None, timeout=UNIX_SOCKET_TIMEOUT):
     If no connection is made during the specified timeout,
     retry until the context is over.
     """
+    ssh_version = subprocess.check_output(['ssh', '-V'],
+                                          stderr=subprocess.STDOUT)
+    log.debug('local SSH version: %r', ssh_version)
     if sock_path is None:
-        sock_path = tempfile.mktemp(prefix='ssh-agent-')
+        sock_path = tempfile.mktemp(prefix='trezor-ssh-agent-')
 
     environ = {'SSH_AUTH_SOCK': sock_path, 'SSH_AGENT_PID': str(os.getpid())}
+    device_mutex = threading.Lock()
     with unix_domain_socket_server(sock_path) as sock:
         sock.settimeout(timeout)
         quit_event = threading.Event()
-        kwargs = dict(sock=sock, handler=handler, quit_event=quit_event)
+        handle_conn = functools.partial(handle_connection,
+                                        handler=handler,
+                                        mutex=device_mutex)
+        kwargs = dict(sock=sock,
+                      handle_conn=handle_conn,
+                      quit_event=quit_event)
         with spawn(server_thread, kwargs):
             try:
                 yield environ

trezor_agent/tests/test_client.py

@@ -3,7 +3,7 @@ import io
 import mock
 import pytest
 
-from .. import client, factory, formats, util
+from .. import client, device, formats, util
 
 ADDR = [2147483661, 2810943954, 3938368396, 3454558782, 3848009040]
 CURVE = 'nist256p1'
@@ -12,49 +12,23 @@ PUBKEY = (b'\x03\xd8(\xb5\xa6`\xbet0\x95\xac:[;]\xdc,\xbd\xdc?\xd7\xc0\xec'
           b'\xdd\xbc+\xfar~\x9dAis')
 PUBKEY_TEXT = ('ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzd'
                'HAyNTYAAABBBNgotaZgvnQwlaw6Wztd3Cy93D/XwOzdvCv6cn6dQWlzNMEQeW'
-               'VUfhvrGljR2Z/CMRONY6ejB+9PnpUOPuzYqi8= ssh://localhost:22\n')
+               'VUfhvrGljR2Z/CMRONY6ejB+9PnpUOPuzYqi8= <localhost:22|nist256p1>\n')
 
 
-class FakeConnection(object):
+class MockDevice(device.interface.Device):  # pylint: disable=abstract-method
 
-    def __init__(self):
-        self.closed = False
+    def connect(self):  # pylint: disable=no-self-use
+        return mock.Mock()
 
-    def close(self):
-        self.closed = True
+    def pubkey(self, identity, ecdh=False):  # pylint: disable=unused-argument
+        assert self.conn
+        return PUBKEY
 
-    def clear_session(self):
-        self.closed = True
-
-    def get_public_node(self, n, ecdsa_curve_name=b'secp256k1'):
-        assert not self.closed
-        assert n == ADDR
-        assert ecdsa_curve_name in {b'secp256k1', b'nist256p1'}
-        result = mock.Mock(spec=[])
-        result.node = mock.Mock(spec=[])
-        result.node.public_key = PUBKEY
-        return result
-
-    def ping(self, msg):
-        assert not self.closed
-        return msg
-
-
-def identity_type(**kwargs):
-    result = mock.Mock(spec=[])
-    result.index = 0
-    result.proto = result.user = result.host = result.port = None
-    result.path = None
-    for k, v in kwargs.items():
-        setattr(result, k, v)
-    return result
-
-
-def load_client():
-    return factory.ClientWrapper(connection=FakeConnection(),
-                                 identity_type=identity_type,
-                                 device_name='DEVICE_NAME',
-                                 call_exception=Exception)
+    def sign(self, identity, blob):
+        """Sign given blob and return the signature (as bytes)."""
+        assert self.conn
+        assert blob == BLOB
+        return SIG
 
 
 BLOB = (b'\x00\x00\x00 \xce\xe0\xc9\xd5\xceu/\xe8\xc5\xf2\xbfR+x\xa1\xcf\xb0'
@@ -66,72 +40,33 @@ BLOB = (b'\x00\x00\x00 \xce\xe0\xc9\xd5\xceu/\xe8\xc5\xf2\xbfR+x\xa1\xcf\xb0'
         b'\xdd\xbc+\xfar~\x9dAis4\xc1\x10yeT~\x1b\xeb\x1aX\xd1\xd9\x9f\xc21'
         b'\x13\x8dc\xa7\xa3\x07\xefO\x9e\x95\x0e>\xec\xd8\xaa/')
 
-SIG = (b'\x00R\x19T\xf2\x84$\xef#\x0e\xee\x04X\xc6\xc3\x99T`\xd1\xd8\xf7!'
+SIG = (b'R\x19T\xf2\x84$\xef#\x0e\xee\x04X\xc6\xc3\x99T`\xd1\xd8\xf7!'
        b'\x862@cx\xb8\xb9i@1\x1b3#\x938\x86]\x97*Y\xb2\x02Xa\xdf@\xecK'
        b'\xdc\xf0H\xab\xa8\xac\xa7? \x8f=C\x88N\xe2')
 
 
 def test_ssh_agent():
-    label = 'localhost:22'
-    c = client.Client(loader=load_client)
-    ident = c.get_identity(label=label)
-    assert ident.host == 'localhost'
-    assert ident.proto == 'ssh'
-    assert ident.port == '22'
-    assert ident.user is None
-    assert ident.path is None
-    assert ident.index == 0
+    identity = device.interface.Identity(identity_str='localhost:22',
+                                         curve_name=CURVE)
+    c = client.Client(device=MockDevice())
+    assert c.get_public_key(identity) == PUBKEY_TEXT
+    signature = c.sign_ssh_challenge(blob=BLOB, identity=identity)
 
-    with c:
-        assert c.get_public_key(label) == PUBKEY_TEXT
+    key = formats.import_public_key(PUBKEY_TEXT)
+    serialized_sig = key['verifier'](sig=signature, msg=BLOB)
 
-        def ssh_sign_identity(identity, challenge_hidden,
-                              challenge_visual, ecdsa_curve_name):
-            assert (client.identity_to_string(identity) ==
-                    client.identity_to_string(ident))
-            assert challenge_hidden == BLOB
-            assert challenge_visual == 'VISUAL'
-            assert ecdsa_curve_name == b'nist256p1'
+    stream = io.BytesIO(serialized_sig)
+    r = util.read_frame(stream)
+    s = util.read_frame(stream)
+    assert not stream.read()
+    assert r[:1] == b'\x00'
+    assert s[:1] == b'\x00'
+    assert r[1:] + s[1:] == SIG
 
-            result = mock.Mock(spec=[])
-            result.public_key = PUBKEY
-            result.signature = SIG
-            return result
+    # pylint: disable=unused-argument
+    def cancel_sign(identity, blob):
+        raise IOError(42, 'ERROR')
 
-        c.client.sign_identity = ssh_sign_identity
-        signature = c.sign_ssh_challenge(label=label, blob=BLOB,
-                                         visual='VISUAL')
-
-        key = formats.import_public_key(PUBKEY_TEXT)
-        serialized_sig = key['verifier'](sig=signature, msg=BLOB)
-
-        stream = io.BytesIO(serialized_sig)
-        r = util.read_frame(stream)
-        s = util.read_frame(stream)
-        assert not stream.read()
-        assert r[:1] == b'\x00'
-        assert s[:1] == b'\x00'
-        assert r[1:] + s[1:] == SIG[1:]
-
-        c.client.call_exception = ValueError
-
-        # pylint: disable=unused-argument
-        def cancel_sign_identity(identity, challenge_hidden,
-                                 challenge_visual, ecdsa_curve_name):
-            raise c.client.call_exception(42, 'ERROR')
-
-        c.client.sign_identity = cancel_sign_identity
-        with pytest.raises(IOError):
-            c.sign_ssh_challenge(label=label, blob=BLOB, visual='VISUAL')
-
-
-def test_utils():
-    identity = mock.Mock(spec=[])
-    identity.proto = 'https'
-    identity.user = 'user'
-    identity.host = 'host'
-    identity.port = '443'
-    identity.path = '/path'
-
-    url = 'https://user@host:443/path'
-    assert client.identity_to_string(identity) == url
+    c.device.sign = cancel_sign
+    with pytest.raises(IOError):
+        c.sign_ssh_challenge(blob=BLOB, identity=identity)

trezor_agent/tests/test_factory.py

@@ -1,97 +0,0 @@
-import mock
-import pytest
-
-from .. import factory
-
-
-def test_load():
-
-    def single():
-        return [0]
-
-    def nothing():
-        return []
-
-    def double():
-        return [1, 2]
-
-    assert factory.load(loaders=[single]) == 0
-    assert factory.load(loaders=[single, nothing]) == 0
-    assert factory.load(loaders=[nothing, single]) == 0
-
-    with pytest.raises(IOError):
-        factory.load(loaders=[])
-
-    with pytest.raises(IOError):
-        factory.load(loaders=[single, single])
-
-    with pytest.raises(IOError):
-        factory.load(loaders=[double])
-
-
-def factory_load_client(**kwargs):
-    # pylint: disable=protected-access
-    return list(factory._load_client(**kwargs))
-
-
-def test_load_nothing():
-    hid_transport = mock.Mock(spec_set=['enumerate'])
-    hid_transport.enumerate.return_value = []
-    result = factory_load_client(
-        name=None,
-        client_type=None,
-        hid_transport=hid_transport,
-        passphrase_ack=None,
-        identity_type=None,
-        required_version=None,
-        call_exception=None)
-    assert result == []
-
-
-def create_client_type(version):
-    conn = mock.Mock(spec=[])
-    conn.features = mock.Mock(spec=[])
-    major, minor, patch = version.split('.')
-    conn.features.device_id = 'DEVICE_ID'
-    conn.features.label = 'LABEL'
-    conn.features.vendor = 'VENDOR'
-    conn.features.major_version = major
-    conn.features.minor_version = minor
-    conn.features.patch_version = patch
-    conn.features.revision = b'\x12\x34\x56\x78'
-    return mock.Mock(spec_set=[], return_value=conn)
-
-
-def test_load_single():
-    hid_transport = mock.Mock(spec_set=['enumerate'])
-    hid_transport.enumerate.return_value = [0]
-    for version in ('1.3.4', '1.3.5', '1.4.0', '2.0.0'):
-        passphrase_ack = mock.Mock(spec_set=[])
-        client_type = create_client_type(version)
-        client_wrapper, = factory_load_client(
-            name='DEVICE_NAME',
-            client_type=client_type,
-            hid_transport=hid_transport,
-            passphrase_ack=passphrase_ack,
-            identity_type=None,
-            required_version='>=1.3.4',
-            call_exception=None)
-        assert client_wrapper.connection is client_type.return_value
-        assert client_wrapper.device_name == 'DEVICE_NAME'
-        client_wrapper.connection.callback_PassphraseRequest('MESSAGE')
-        assert passphrase_ack.mock_calls == [mock.call(passphrase='')]
-
-
-def test_load_old():
-    hid_transport = mock.Mock(spec_set=['enumerate'])
-    hid_transport.enumerate.return_value = [0]
-    for version in ('1.3.3', '1.2.5', '1.1.0', '0.9.9'):
-        with pytest.raises(ValueError):
-            factory_load_client(
-                name='DEVICE_NAME',
-                client_type=create_client_type(version),
-                hid_transport=hid_transport,
-                passphrase_ack=None,
-                identity_type=None,
-                required_version='>=1.3.4',
-                call_exception=None)

trezor_agent/tests/test_formats.py

@@ -29,7 +29,7 @@ def test_parse_public_key():
     assert key['name'] == b'home'
     assert key['point'] == _point
 
-    assert key['curve'] == b'nist256p1'
+    assert key['curve'] == 'nist256p1'
     assert key['fingerprint'] == '4b:19:bc:0f:c8:7e:dc:fa:1a:e3:c2:ff:6f:e0:80:a2'  # nopep8
     assert key['type'] == b'ecdsa-sha2-nistp256'
 
@@ -46,7 +46,7 @@ def test_parse_ed25519():
               'fSO8nLIi736is+f0erq28RTc7CkM11NZtTKR hello\n')
     p = formats.import_public_key(pubkey)
     assert p['name'] == b'hello'
-    assert p['curve'] == b'ed25519'
+    assert p['curve'] == 'ed25519'
 
     BLOB = (b'\x00\x00\x00\x0bssh-ed25519\x00\x00\x00 P]\x17kc}#'
             b'\xbc\x9c\xb2"\xef~\xa2\xb3\xe7\xf4z\xba\xb6\xf1\x14'
@@ -93,3 +93,11 @@ def test_curve_mismatch():
 def test_serialize_error():
     with pytest.raises(TypeError):
         formats.serialize_verifying_key(None)
+
+
+def test_get_ecdh_curve_name():
+    for c in [formats.CURVE_NIST256, formats.ECDH_CURVE25519]:
+        assert c == formats.get_ecdh_curve_name(c)
+
+    assert (formats.ECDH_CURVE25519 ==
+            formats.get_ecdh_curve_name(formats.CURVE_ED25519))

trezor_agent/tests/test_protocol.py

@@ -1,6 +1,6 @@
 import pytest
 
-from .. import formats, protocol
+from .. import device, formats, protocol
 
 # pylint: disable=line-too-long
 
@@ -17,6 +17,7 @@ NIST256_SIGN_REPLY = b'\x00\x00\x00j\x0e\x00\x00\x00e\x00\x00\x00\x13ecdsa-sha2-
 
 def test_list():
     key = formats.import_public_key(NIST256_KEY)
+    key['identity'] = device.interface.Identity('ssh://localhost', 'nist256p1')
     h = protocol.Handler(keys=[key], signer=None)
     reply = h.handle(LIST_MSG)
     assert reply == LIST_NIST256_REPLY
@@ -28,14 +29,15 @@ def test_unsupported():
     assert reply == b'\x00\x00\x00\x01\x05'
 
 
-def ecdsa_signer(label, blob):
-    assert label == 'ssh://localhost'
+def ecdsa_signer(identity, blob):
+    assert str(identity) == '<ssh://localhost|nist256p1>'
     assert blob == NIST256_BLOB
     return NIST256_SIG
 
 
 def test_ecdsa_sign():
     key = formats.import_public_key(NIST256_KEY)
+    key['identity'] = device.interface.Identity('ssh://localhost', 'nist256p1')
     h = protocol.Handler(keys=[key], signer=ecdsa_signer)
     reply = h.handle(NIST256_SIGN_MSG)
     assert reply == NIST256_SIGN_REPLY
@@ -43,31 +45,30 @@ def test_ecdsa_sign():
 
 def test_sign_missing():
     h = protocol.Handler(keys=[], signer=ecdsa_signer)
-
     with pytest.raises(KeyError):
         h.handle(NIST256_SIGN_MSG)
 
 
 def test_sign_wrong():
-    def wrong_signature(label, blob):
-        assert label == 'ssh://localhost'
+    def wrong_signature(identity, blob):
+        assert str(identity) == '<ssh://localhost|nist256p1>'
         assert blob == NIST256_BLOB
         return b'\x00' * 64
 
     key = formats.import_public_key(NIST256_KEY)
+    key['identity'] = device.interface.Identity('ssh://localhost', 'nist256p1')
     h = protocol.Handler(keys=[key], signer=wrong_signature)
-
     with pytest.raises(ValueError):
         h.handle(NIST256_SIGN_MSG)
 
 
 def test_sign_cancel():
-    def cancel_signature(label, blob):  # pylint: disable=unused-argument
+    def cancel_signature(identity, blob):  # pylint: disable=unused-argument
         raise IOError()
 
     key = formats.import_public_key(NIST256_KEY)
+    key['identity'] = device.interface.Identity('ssh://localhost', 'nist256p1')
     h = protocol.Handler(keys=[key], signer=cancel_signature)
-
     assert h.handle(NIST256_SIGN_MSG) == protocol.failure()
 
 
@@ -79,14 +80,15 @@ ED25519_BLOB = b'''\x00\x00\x00 i3\xae}yk\\\xa1L\xb9\xe1\xbf\xbc\x8e\x87\r\x0e\x
 ED25519_SIG = b'''\x8eb)\xa6\xe9P\x83VE\xfbq\xc6\xbf\x1dV3\xe3<O\x11\xc0\xfa\xe4\xed\xb8\x81.\x81\xc8\xa6\xba\x10RA'a\xbc\xa9\xd3\xdb\x98\x07\xf0\x1a\x9c4\x84<\xaf\x99\xb7\xe5G\xeb\xf7$\xc1\r\x86f\x16\x8e\x08\x05'''  # nopep8
 
 
-def ed25519_signer(label, blob):
-    assert label == 'ssh://localhost'
+def ed25519_signer(identity, blob):
+    assert str(identity) == '<ssh://localhost|ed25519>'
     assert blob == ED25519_BLOB
     return ED25519_SIG
 
 
 def test_ed25519_sign():
     key = formats.import_public_key(ED25519_KEY)
+    key['identity'] = device.interface.Identity('ssh://localhost', 'ed25519')
     h = protocol.Handler(keys=[key], signer=ed25519_signer)
     reply = h.handle(ED25519_SIGN_MSG)
     assert reply == ED25519_SIGN_REPLY

trezor_agent/tests/test_server.py

@@ -1,3 +1,4 @@
+import functools
 import io
 import os
 import socket
@@ -37,30 +38,32 @@ class FakeSocket(object):
 
 
 def test_handle():
+    mutex = threading.Lock()
+
     handler = protocol.Handler(keys=[], signer=None)
     conn = FakeSocket()
-    server.handle_connection(conn, handler)
+    server.handle_connection(conn, handler, mutex)
 
     msg = bytearray([protocol.msg_code('SSH_AGENTC_REQUEST_RSA_IDENTITIES')])
     conn = FakeSocket(util.frame(msg))
-    server.handle_connection(conn, handler)
+    server.handle_connection(conn, handler, mutex)
     assert conn.tx.getvalue() == b'\x00\x00\x00\x05\x02\x00\x00\x00\x00'
 
     msg = bytearray([protocol.msg_code('SSH2_AGENTC_REQUEST_IDENTITIES')])
     conn = FakeSocket(util.frame(msg))
-    server.handle_connection(conn, handler)
+    server.handle_connection(conn, handler, mutex)
     assert conn.tx.getvalue() == b'\x00\x00\x00\x05\x0C\x00\x00\x00\x00'
 
     msg = bytearray([protocol.msg_code('SSH2_AGENTC_ADD_IDENTITY')])
     conn = FakeSocket(util.frame(msg))
-    server.handle_connection(conn, handler)
+    server.handle_connection(conn, handler, mutex)
     conn.tx.seek(0)
     reply = util.read_frame(conn.tx)
     assert reply == util.pack('B', protocol.msg_code('SSH_AGENT_FAILURE'))
 
     conn_mock = mock.Mock(spec=FakeSocket)
     conn_mock.recv.side_effect = [Exception, EOFError]
-    server.handle_connection(conn=conn_mock, handler=None)
+    server.handle_connection(conn=conn_mock, handler=None, mutex=mutex)
 
 
 def test_server_thread():
@@ -78,8 +81,10 @@ def test_server_thread():
         def getsockname(self):  # pylint: disable=no-self-use
             return 'fake_server'
 
+    handler = protocol.Handler(keys=[], signer=None),
+    handle_conn = functools.partial(server.handle_connection, handler=handler)
     server.server_thread(sock=FakeServer(),
-                         handler=protocol.Handler(keys=[], signer=None),
+                         handle_conn=handle_conn,
                          quit_event=quit_event)
 
 

trezor_agent/tests/test_util.py

@@ -46,3 +46,58 @@ def test_send_recv():
     assert util.recv(s, 2) == b'3*'
 
     pytest.raises(EOFError, util.recv, s, 1)
+
+
+def test_crc24():
+    assert util.crc24(b'') == b'\xb7\x04\xce'
+    assert util.crc24(b'1234567890') == b'\x8c\x00\x72'
+
+
+def test_bit():
+    assert util.bit(6, 3) == 0
+    assert util.bit(6, 2) == 1
+    assert util.bit(6, 1) == 1
+    assert util.bit(6, 0) == 0
+
+
+def test_split_bits():
+    assert util.split_bits(0x1234, 4, 8, 4) == [0x1, 0x23, 0x4]
+
+
+def test_hexlify():
+    assert util.hexlify(b'\x12\x34\xab\xcd') == '1234ABCD'
+
+
+def test_low_bits():
+    assert util.low_bits(0x1234, 12) == 0x234
+    assert util.low_bits(0x1234, 32) == 0x1234
+    assert util.low_bits(0x1234, 0) == 0
+
+
+def test_readfmt():
+    stream = io.BytesIO(b'ABC\x12\x34')
+    assert util.readfmt(stream, 'B') == (65,)
+    assert util.readfmt(stream, '>2sH') == (b'BC', 0x1234)
+
+
+def test_prefix_len():
+    assert util.prefix_len('>H', b'ABCD') == b'\x00\x04ABCD'
+
+
+def test_reader():
+    stream = io.BytesIO(b'ABC\x12\x34')
+    r = util.Reader(stream)
+    assert r.read(1) == b'A'
+    assert r.readfmt('2s') == b'BC'
+
+    dst = io.BytesIO()
+    with r.capture(dst):
+        assert r.readfmt('>H') == 0x1234
+    assert dst.getvalue() == b'\x12\x34'
+
+    with pytest.raises(EOFError):
+        r.read(1)
+
+
+def test_setup_logging():
+    util.setup_logging(verbosity=10)

trezor_agent/util.py

@@ -1,7 +1,12 @@
 """Various I/O and serialization utilities."""
+import binascii
+import contextlib
 import io
+import logging
 import struct
 
+log = logging.getLogger(__name__)
+
 
 def send(conn, data):
     """Send data blob to connection socket."""
@@ -60,7 +65,7 @@ def num2bytes(value, size):
         res.append(value & 0xFF)
         value = value >> 8
     assert value == 0
-    return bytearray(list(reversed(res)))
+    return bytes(bytearray(list(reversed(res))))
 
 
 def pack(fmt, *args):
@@ -75,3 +80,108 @@ def frame(*msgs):
         res.write(msg)
     msg = res.getvalue()
     return pack('L', len(msg)) + msg
+
+
+def crc24(blob):
+    """See https://tools.ietf.org/html/rfc4880#section-6.1 for details."""
+    CRC24_INIT = 0x0B704CE
+    CRC24_POLY = 0x1864CFB
+
+    crc = CRC24_INIT
+    for octet in bytearray(blob):
+        crc ^= (octet << 16)
+        for _ in range(8):
+            crc <<= 1
+            if crc & 0x1000000:
+                crc ^= CRC24_POLY
+    assert 0 <= crc < 0x1000000
+    crc_bytes = struct.pack('>L', crc)
+    assert crc_bytes[:1] == b'\x00'
+    return crc_bytes[1:]
+
+
+def bit(value, i):
+    """Extract the i-th bit out of value."""
+    return 1 if value & (1 << i) else 0
+
+
+def low_bits(value, n):
+    """Extract the lowest n bits out of value."""
+    return value & ((1 << n) - 1)
+
+
+def split_bits(value, *bits):
+    """
+    Split integer value into list of ints, according to `bits` list.
+
+    For example, split_bits(0x1234, 4, 8, 4) == [0x1, 0x23, 0x4]
+    """
+    result = []
+    for b in reversed(bits):
+        mask = (1 << b) - 1
+        result.append(value & mask)
+        value = value >> b
+    assert value == 0
+
+    result.reverse()
+    return result
+
+
+def readfmt(stream, fmt):
+    """Read and unpack an object from stream, using a struct format string."""
+    size = struct.calcsize(fmt)
+    blob = stream.read(size)
+    return struct.unpack(fmt, blob)
+
+
+def prefix_len(fmt, blob):
+    """Prefix `blob` with its size, serialized using `fmt` format."""
+    return struct.pack(fmt, len(blob)) + blob
+
+
+def hexlify(blob):
+    """Utility for consistent hexadecimal formatting."""
+    return binascii.hexlify(blob).decode('ascii').upper()
+
+
+class Reader(object):
+    """Read basic type objects out of given stream."""
+
+    def __init__(self, stream):
+        """Create a non-capturing reader."""
+        self.s = stream
+        self._captured = None
+
+    def readfmt(self, fmt):
+        """Read a specified object, using a struct format string."""
+        size = struct.calcsize(fmt)
+        blob = self.read(size)
+        obj, = struct.unpack(fmt, blob)
+        return obj
+
+    def read(self, size=None):
+        """Read `size` bytes from stream."""
+        blob = self.s.read(size)
+        if size is not None and len(blob) < size:
+            raise EOFError
+        if self._captured:
+            self._captured.write(blob)
+        return blob
+
+    @contextlib.contextmanager
+    def capture(self, stream):
+        """Capture all data read during this context."""
+        self._captured = stream
+        try:
+            yield
+        finally:
+            self._captured = None
+
+
+def setup_logging(verbosity, **kwargs):
+    """Configure logging for this tool."""
+    fmt = ('%(asctime)s %(levelname)-12s %(message)-100s '
+           '[%(filename)s:%(lineno)d]')
+    levels = [logging.WARNING, logging.INFO, logging.DEBUG]
+    level = levels[min(verbosity, len(levels) - 1)]
+    logging.basicConfig(format=fmt, level=level, **kwargs)