bump version

gpg: replace TREZOR_GPG_USER_ID usage in gpg-agent mode

README-GPG.md

@@ -8,19 +8,19 @@ First, verify that you have GPG 2.1+ [installed](https://gist.github.com/vt0r/a2
 
 ```
 $ gpg2 --version | head -n1
-gpg (GnuPG) 2.1.11
+gpg (GnuPG) 2.1.15
 ```
 
-Update you TREZOR firmware to the latest version (at least [c720614](https://github.com/trezor/trezor-mcu/commit/c720614f6e9b9c07f446c95bda0257980d942871)).
+Update you TREZOR firmware to the latest version (at least v1.4.0).
 
-Install latest `trezor-agent` package from [gpg-agent](https://github.com/romanz/trezor-agent/commits/gpg-agent) branch:
+Install latest `trezor-agent` package from GitHub:
 ```
 $ pip install --user git+https://github.com/romanz/trezor-agent.git
 ```
 
 Define your GPG user ID as an environment variable:
 ```
-$ export TREZOR_GPG_USER_ID="John Doe <john@doe.bit>"
+$ TREZOR_GPG_USER_ID="John Doe <john@doe.bit>"
 ```
 
 There are two ways to generate TREZOR-based GPG public keys, as described below.
@@ -28,12 +28,12 @@ There are two ways to generate TREZOR-based GPG public keys, as described below.
 ## 1. generate a new GPG identity:
 
 ```
-$ trezor-gpg create | gpg2 --import              # use the TREZOR to confirm signing the primary key
+$ trezor-gpg create "${TREZOR_GPG_USER_ID}" | gpg2 --import           # use the TREZOR to confirm signing the primary key
 gpg: key 5E4D684D: public key "John Doe <john@doe.bit>" imported
 gpg: Total number processed: 1
 gpg:               imported: 1
 
-$ gpg2 --edit "${TREZOR_GPG_USER_ID}" trust      # set this key to ultimate trust (option #5)
+$ gpg2 --edit "${TREZOR_GPG_USER_ID}" trust                           # set this key to ultimate trust (option #5)
 
 $ gpg2 -k
 /home/roman/.gnupg/pubring.kbx
@@ -46,14 +46,14 @@ sub   nistp256/A31D9E25 2016-06-17 [E]
 ## 2. generate a new subkey for an existing GPG identity:
 
 ```
-$ gpg2 -k                                        # suppose there is already a GPG primary key
+$ gpg2 -k                                                             # suppose there is already a GPG primary key
 /home/roman/.gnupg/pubring.kbx
 ------------------------------
 pub   rsa2048/87BB07B4 2016-06-17 [SC]
 uid         [ultimate] John Doe <john@doe.bit>
 sub   rsa2048/7176D31F 2016-06-17 [E]
 
-$ trezor-gpg create --subkey | gpg2 --import     # use the TREZOR to confirm signing the subkey
+$ trezor-gpg create --subkey "${TREZOR_GPG_USER_ID}" | gpg2 --import  # use the TREZOR to confirm signing the subkey
 gpg: key 87BB07B4: "John Doe <john@doe.bit>" 2 new signatures
 gpg: key 87BB07B4: "John Doe <john@doe.bit>" 2 new subkeys
 gpg: Total number processed: 1
@@ -83,13 +83,13 @@ when you are done with the TREZOR-based GPG operations.
 ```
 $ echo "Hello World!" | gpg2 --sign | gpg2 --verify
 gpg: Signature made Fri 17 Jun 2016 08:55:13 PM IDT using ECDSA key ID 5E4D684D
-gpg: Good signature from "Roman Zeyde <roman.zeyde@gmail.com>" [ultimate]
+gpg: Good signature from "John Doe <john@doe.bit>" [ultimate]
 ```
 ## Encrypt and decrypt GPG messages:
 ```
 $ date | gpg2 --encrypt -r "${TREZOR_GPG_USER_ID}" | gpg2 --decrypt
 gpg: encrypted with 256-bit ECDH key, ID A31D9E25, created 2016-06-17
-      "Roman Zeyde <roman.zeyde@gmail.com>"
+      "John Doe <john@doe.bit>"
 Fri Jun 17 20:55:31 IDT 2016
 ```
 
@@ -101,4 +101,4 @@ $ git commit --gpg-sign                      # create GPG-signed commit
 $ git log --show-signature -1                # verify commit signature
 $ git tag --sign "TAG"                       # create GPG-signed tag
 $ git verify-tag "TAG"                       # verify tag signature
-```
+```

README-SSH.md

@@ -9,38 +9,17 @@
 ## Using for GitHub SSH authentication (via `trezor-git` utility)
 [![GitHub](https://asciinema.org/a/38337.png)](https://asciinema.org/a/38337)
 
-# Installation
-
-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 Cython trezor
-
-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](https://mytrezor.com/data/firmware/releases.json) version (at least v1.3.4):
-
-	$ trezorctl get_features
-	vendor: "bitcointrezor.com"
-	major_version: 1
-	minor_version: 3
-	patch_version: 4
-	...
-
 # 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...
+	/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://ssh.hostname.com
+	ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBGSevcDwmT+QaZPUEWUUjTeZRBICChxMKuJ7dRpBSF8+qt+8S1GBK5Zj8Xicc8SHG/SE/EXKUL2UU3kcUzE7ADQ= ssh://user@ssh.hostname.com
 
-Append `hostname.pub` contents to `~/.ssh/authorized_keys`
+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.
 
@@ -48,9 +27,9 @@ would allow you to login using the corresponding private key signature.
 
 Run:
 
-	/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...
+	/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
 
@@ -64,3 +43,38 @@ Run:
 	~ $
 
 Make sure to confirm SSH signature on the Trezor device when requested.
+
+## Accessing remote Git 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
+
+
+# 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

@@ -11,8 +11,43 @@ See SatoshiLabs' blog posts about this feature:
 - [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)
 
-For usage with SSH, see the [following instructions](README-SSH.md).
+## Installation
 
-For usage with GPG, see the [following instructions](README-GPG.md).
+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 install Cython trezor
+
+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](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: 4
+	patch_version: 0
+	...
+
+If you have an error regarding `protobuf` imports (after installing it), please see [this issue](https://github.com/romanz/trezor-agent/issues/28).
+
+## Usage
+
+For SSH, see the [following instructions](README-SSH.md).
+
+For GPG, see the [following instructions](README-GPG.md).
+
+See [here](https://github.com/romanz/python-trezor#pin-entering) for PIN entering instructions.
+
+## Troubleshooting
+
+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)

setup.py

@@ -3,13 +3,13 @@ from setuptools import setup
 
 setup(
     name='trezor_agent',
-    version='0.6.6',
+    version='0.7.4',
     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', 'trezor_agent.gpg'],
-    install_requires=['ecdsa>=0.13', 'ed25519>=1.4', 'Cython>=0.23.4', 'protobuf>=2.6.1', 'trezor>=0.6.12', 'semver>=2.2'],
+    install_requires=['ecdsa>=0.13', 'ed25519>=1.4', 'Cython>=0.23.4', 'protobuf>=3.0.0', 'trezor>=0.7.4', 'semver>=2.2'],
     platforms=['POSIX'],
     classifiers=[
         'Environment :: Console',
@@ -27,6 +27,10 @@ setup(
         'Topic :: Security',
         'Topic :: Utilities',
     ],
+    extras_require={
+        'trezorlib': ['python-trezor>=0.7.4'],
+        'keepkeylib': ['keepkey>=0.7.3'],
+    },
     entry_points={'console_scripts': [
         'trezor-agent = trezor_agent.__main__:run_agent',
         'trezor-git = trezor_agent.__main__:run_git',

tox.ini

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

trezor_agent/__main__.py

@@ -7,14 +7,14 @@ import re
 import subprocess
 import sys
 
-from . import client, formats, protocol, server
+from . import client, 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 = util.string_to_identity(label, identity_type=dict)
 
     args = []
     if 'port' in identity:
@@ -73,15 +73,6 @@ 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:
@@ -132,7 +123,7 @@ def handle_connection_error(func):
 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
@@ -161,7 +152,7 @@ def run_agent(client_factory=client.Client):
 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)
+    util.setup_logging(verbosity=args.verbose)
 
     with client_factory(curve=args.ecdsa_curve_name) as conn:
         label = git_host(args.remote, ['pushurl', 'url'])

trezor_agent/client.py

@@ -6,8 +6,6 @@ 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
 
@@ -33,14 +31,13 @@ class Client(object):
         return self
 
     def __exit__(self, *args):
-        """Forget PIN, shutdown screen and disconnect."""
+        """Keep the session open (doesn't forget PIN)."""
         log.info('disconnected from %s', self.device_name)
-        self.client.clear_session()
         self.client.close()
 
     def get_identity(self, label, index=0):
         """Parse label string into Identity protobuf."""
-        identity = string_to_identity(label, self.identity_type)
+        identity = util.string_to_identity(label, self.identity_type)
         identity.proto = 'ssh'
         identity.index = index
         return identity
@@ -48,10 +45,10 @@ class Client(object):
     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
+        label = util.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)
+        addr = util.get_bip32_address(identity)
         node = self.client.get_public_node(n=addr,
                                            ecdsa_curve_name=self.curve)
 
@@ -70,7 +67,7 @@ class Client(object):
         log.debug('hidden challenge size: %d bytes', len(blob))
 
         log.info('please confirm user "%s" login to "%s" using %s...',
-                 msg['user'], label, self.device_name)
+                 msg['user'].decode('ascii'), label, self.device_name)
 
         try:
             result = self.client.sign_identity(identity=identity,
@@ -93,55 +90,6 @@ class Client(object):
         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, ecdh=False):
-    """Compute BIP32 derivation address according to SLIP-0013/0017."""
-    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
-    addr_0 = [13, 17][bool(ecdh)]
-    address_n = [addr_0] + list(util.recv(s, '<LLLL'))
-    return [(hardened | value) for value in address_n]
-
-
 def _parse_ssh_blob(data):
     res = {}
     i = io.BytesIO(data)

trezor_agent/factory.py

@@ -1,10 +1,14 @@
 """Thin wrapper around trezor/keepkey libraries."""
+from __future__ import absolute_import
+
 import binascii
 import collections
 import logging
 
 import semver
 
+from . import util
+
 log = logging.getLogger(__name__)
 
 ClientWrapper = collections.namedtuple(
@@ -41,6 +45,7 @@ def _load_client(name, client_type, hid_transport,
                             identity_type=identity_type,
                             device_name=name,
                             call_exception=call_exception)
+        return
 
 
 def _load_trezor():
@@ -56,8 +61,9 @@ def _load_trezor():
                             identity_type=IdentityType,
                             required_version='>=1.4.0',
                             call_exception=CallException)
-    except ImportError:
-        log.exception('Missing module: install via "pip install trezor"')
+    except ImportError as e:
+        log.warning('%s: install via "pip install trezor" '
+                    'if you need to support this device', e)
 
 
 def _load_keepkey():
@@ -73,13 +79,163 @@ def _load_keepkey():
                             identity_type=IdentityType,
                             required_version='>=1.0.4',
                             call_exception=CallException)
-    except ImportError:
-        log.exception('Missing module: install via "pip install keepkey"')
+    except ImportError as e:
+        log.warning('%s: install via "pip install keepkey" '
+                    'if you need to support this device', e)
 
 
+def _load_ledger():
+    import struct
+
+    class LedgerClientConnection(object):
+        def __init__(self, dongle):
+            self.dongle = dongle
+
+        @staticmethod
+        def expand_path(path):
+            result = ""
+            for pathElement in path:
+                result = result + struct.pack(">I", pathElement)
+            return result
+
+        @staticmethod
+        def convert_public_key(ecdsa_curve_name, result):
+            from trezorlib.messages_pb2 import PublicKey  # pylint: disable=import-error
+            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 = chr(0) + str(keyY)
+            publicKey = PublicKey()
+            publicKey.node.public_key = str(result)
+            return publicKey
+
+        # pylint: disable=unused-argument
+        def get_public_node(self, n, ecdsa_curve_name="secp256k1", show_display=False):
+            donglePath = LedgerClientConnection.expand_path(n)
+            if ecdsa_curve_name == "nist256p1":
+                p2 = "01"
+            else:
+                p2 = "02"
+            apdu = "800200" + p2
+            apdu = apdu.decode('hex')
+            apdu += chr(len(donglePath) + 1) + chr(len(donglePath) / 4)
+            apdu += donglePath
+            result = bytearray(self.dongle.exchange(bytes(apdu)))[1:]
+            return LedgerClientConnection.convert_public_key(ecdsa_curve_name, result)
+
+        # pylint: disable=too-many-locals
+        def sign_identity(self, identity, challenge_hidden, challenge_visual,
+                          ecdsa_curve_name="secp256k1"):
+            from trezorlib.messages_pb2 import SignedIdentity  # pylint: disable=import-error
+            n = util.get_bip32_address(identity)
+            donglePath = LedgerClientConnection.expand_path(n)
+            if identity.proto == 'ssh':
+                ins = "04"
+                p1 = "00"
+            else:
+                ins = "08"
+                p1 = "00"
+            if ecdsa_curve_name == "nist256p1":
+                p2 = "81" if identity.proto == 'ssh' else "01"
+            else:
+                p2 = "82" if identity.proto == 'ssh' else "02"
+            apdu = "80" + ins + p1 + p2
+            apdu = apdu.decode('hex')
+            apdu += chr(len(challenge_hidden) + len(donglePath) + 1)
+            apdu += chr(len(donglePath) / 4) + donglePath
+            apdu += challenge_hidden
+            result = bytearray(self.dongle.exchange(bytes(apdu)))
+            if ecdsa_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
+                signature = SignedIdentity()
+                signature.signature = chr(0) + str(r) + str(s)
+                if identity.proto == 'ssh':
+                    keyData = result[offset:]
+                    pk = LedgerClientConnection.convert_public_key(ecdsa_curve_name, keyData)
+                    signature.public_key = pk.node.public_key
+                return signature
+            else:
+                signature = SignedIdentity()
+                signature.signature = chr(0) + str(result[0:64])
+                if identity.proto == 'ssh':
+                    keyData = result[64:]
+                    pk = LedgerClientConnection.convert_public_key(ecdsa_curve_name, keyData)
+                    signature.public_key = pk.node.public_key
+                return signature
+
+        def get_ecdh_session_key(self, identity, peer_public_key, ecdsa_curve_name="secp256k1"):
+            from trezorlib.messages_pb2 import ECDHSessionKey  # pylint: disable=import-error
+            n = util.get_bip32_address(identity, True)
+            donglePath = LedgerClientConnection.expand_path(n)
+            if ecdsa_curve_name == "nist256p1":
+                p2 = "01"
+            else:
+                p2 = "02"
+            apdu = "800a00" + p2
+            apdu = apdu.decode('hex')
+            apdu += chr(len(peer_public_key) + len(donglePath) + 1)
+            apdu += chr(len(donglePath) / 4) + donglePath
+            apdu += peer_public_key
+            result = bytearray(self.dongle.exchange(bytes(apdu)))
+            sessionKey = ECDHSessionKey()
+            sessionKey.session_key = str(result)
+            return sessionKey
+
+        def clear_session(self):
+            pass
+
+        def close(self):
+            self.dongle.close()
+
+        # pylint: disable=unused-argument
+        # pylint: disable=no-self-use
+        def ping(self, msg, button_protection=False, pin_protection=False,
+                 passphrase_protection=False):
+            return msg
+
+    class CallException(Exception):
+        def __init__(self, code, message):
+            super(CallException, self).__init__()
+            self.args = [code, message]
+    try:
+        from ledgerblue.comm import getDongle
+    except ImportError as e:
+        log.warning('%s: install via "pip install ledgerblue" '
+                    'if you need to support this device', e)
+        return
+    # pylint: disable=bare-except
+    try:
+        from trezorlib.types_pb2 import IdentityType  # pylint: disable=import-error
+        dongle = getDongle()
+    except:
+        return
+    yield ClientWrapper(connection=LedgerClientConnection(dongle),
+                        identity_type=IdentityType,
+                        device_name="ledger",
+                        call_exception=CallException)
+
 LOADERS = [
     _load_trezor,
-    _load_keepkey
+    _load_keepkey,
+    _load_ledger
 ]
 
 

trezor_agent/formats.py

@@ -11,11 +11,15 @@ from . import util
 
 log = logging.getLogger(__name__)
 
-# Supported ECDSA curves
+# 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-'
@@ -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/__main__.py

@@ -3,42 +3,42 @@
 import argparse
 import contextlib
 import logging
-import os
 import sys
 import time
 
-from . import agent, encode, keyring, protocol
-from .. import server
+import semver
+
+from . import agent, device, encode, keyring, protocol
+from .. import formats, server, util
 
 log = logging.getLogger(__name__)
 
 
 def run_create(args):
     """Generate a new pubkey for a new/existing GPG identity."""
-    user_id = os.environ['TREZOR_GPG_USER_ID']
     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)
-    conn = encode.HardwareSigner(user_id=user_id,
+    conn = device.HardwareSigner(user_id=args.user_id,
                                  curve_name=args.ecdsa_curve)
     verifying_key = conn.pubkey(ecdh=False)
     decryption_key = conn.pubkey(ecdh=True)
 
     if args.subkey:
-        primary_bytes = keyring.export_public_key(user_id=user_id)
+        primary_bytes = keyring.export_public_key(user_id=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=args.ecdsa_curve, created=args.time,
-            verifying_key=decryption_key, ecdh=True)
+            curve_name=formats.get_ecdh_curve_name(args.ecdsa_curve),
+            created=args.time, verifying_key=decryption_key, ecdh=True)
         result = encode.create_subkey(primary_bytes=primary_bytes,
-                                      pubkey=signing_key,
+                                      subkey=signing_key,
                                       signer_func=conn.sign)
         result = encode.create_subkey(primary_bytes=result,
-                                      pubkey=encryption_key,
+                                      subkey=encryption_key,
                                       signer_func=conn.sign)
     else:
         # primary key for signing
@@ -47,14 +47,14 @@ def run_create(args):
             verifying_key=verifying_key, ecdh=False)
         # subkey for encryption
         subkey = protocol.PublicKey(
-            curve_name=args.ecdsa_curve, created=args.time,
-            verifying_key=decryption_key, ecdh=True)
+            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=user_id,
+        result = encode.create_primary(user_id=args.user_id,
                                        pubkey=primary,
                                        signer_func=conn.sign)
         result = encode.create_subkey(primary_bytes=result,
-                                      pubkey=subkey,
+                                      subkey=subkey,
                                       signer_func=conn.sign)
 
     sys.stdout.write(protocol.armor(result, 'PUBLIC KEY BLOCK'))
@@ -66,18 +66,22 @@ def run_agent(args):  # pylint: disable=unused-argument
     with server.unix_domain_socket_server(sock_path) as sock:
         for conn in agent.yield_connections(sock):
             with contextlib.closing(conn):
-                agent.handle_connection(conn)
+                try:
+                    agent.handle_connection(conn)
+                except Exception as e:  # pylint: disable=broad-except
+                    log.exception('gpg-agent failed: %s', e)
 
 
 def main():
     """Main function."""
     p = argparse.ArgumentParser()
-    p.add_argument('-v', '--verbose', action='store_true', default=False)
+    p.add_argument('-v', '--verbose', default=0, action='count')
     subparsers = p.add_subparsers()
     subparsers.required = True
     subparsers.dest = 'command'
 
     create_cmd = subparsers.add_parser('create')
+    create_cmd.add_argument('user_id')
     create_cmd.add_argument('-s', '--subkey', action='store_true', default=False)
     create_cmd.add_argument('-e', '--ecdsa-curve', default='nist256p1')
     create_cmd.add_argument('-t', '--time', type=int, default=int(time.time()))
@@ -87,12 +91,18 @@ def main():
     agent_cmd.set_defaults(run=run_agent)
 
     args = p.parse_args()
-    logging.basicConfig(level=logging.DEBUG if args.verbose else logging.INFO,
-                        format='%(asctime)s %(levelname)-10s %(message)s')
+    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!')
-    args.run(args)
+
+    existing_gpg = keyring.gpg_version().decode('ascii')
+    required_gpg = '>=2.1.15'
+    if semver.match(existing_gpg, required_gpg):
+        args.run(args)
+    else:
+        log.error('Existing gpg2 has version "%s" (%s required)',
+                  existing_gpg, required_gpg)
 
 
 if __name__ == '__main__':

trezor_agent/gpg/agent.py

@@ -2,9 +2,8 @@
 import binascii
 import contextlib
 import logging
-import os
 
-from . import decode, encode, keyring
+from . import decode, device, keyring, protocol
 from .. import util
 
 log = logging.getLogger(__name__)
@@ -25,8 +24,9 @@ def yield_connections(sock):
 
 def serialize(data):
     """Serialize data according to ASSUAN protocol."""
-    for c in ['%', '\n', '\r']:
-        data = data.replace(c, '%{:02X}'.format(ord(c)))
+    for c in [b'%', b'\n', b'\r']:
+        escaped = '%{:02X}'.format(ord(c)).encode('ascii')
+        data = data.replace(c, escaped)
     return data
 
 
@@ -34,19 +34,40 @@ 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 '(7:sig-val(5:ecdsa(1:r32:{})(1:s32:{})))'.format(r, s)
+    return b'(7:sig-val(5:ecdsa(1:r32:' + r + b')(1:s32:' + s + b')))'
+
+
+@contextlib.contextmanager
+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']
+    curve_name = protocol.get_curve_name_by_oid(pubkey_dict['curve_oid'])
+    ecdh = (pubkey_dict['algo'] == protocol.ECDH_ALGO_ID)
+
+    conn = device.HardwareSigner(user_id, curve_name=curve_name)
+    with contextlib.closing(conn):
+        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
+        yield conn
 
 
 def pksign(keygrip, digest, algo):
     """Sign a message digest using a private EC key."""
-    assert algo == '8'
-    user_id = os.environ['TREZOR_GPG_USER_ID']
-    pubkey_dict = decode.load_public_key(
-        pubkey_bytes=keyring.export_public_key(user_id=user_id),
-        use_custom=True, ecdh=False)
-    pubkey, conn = encode.load_from_public_key(pubkey_dict=pubkey_dict)
-    with contextlib.closing(conn):
-        assert pubkey.keygrip == binascii.unhexlify(keygrip)
+    assert algo == b'8', 'Unsupported hash algorithm ID {}'.format(algo)
+    keygrip_bytes = binascii.unhexlify(keygrip)
+    with open_connection(keygrip_bytes) as conn:
         r, s = conn.sign(binascii.unhexlify(digest))
         result = sig_encode(r, s)
         log.debug('result: %r', result)
@@ -54,17 +75,15 @@ def pksign(keygrip, digest, algo):
 
 
 def _serialize_point(data):
-    data = '{}:'.format(len(data)) + data
+    prefix = '{}:'.format(len(data)).encode('ascii')
     # https://www.gnupg.org/documentation/manuals/assuan/Server-responses.html
-    for c in ['%', '\n', '\r']:
-        data = data.replace(c, '%{:02X}'.format(ord(c)))
-    return '(5:value' + data + ')'
+    return b'(5:value' + serialize(prefix + data) + b')'
 
 
 def parse_ecdh(line):
     """Parse ECDH request and return remote public key."""
-    prefix, line = line.split(' ', 1)
-    assert prefix == 'D'
+    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
@@ -73,7 +92,7 @@ def parse_ecdh(line):
     assert exp[0] == b'ecdh'
     items = exp[1:]
     log.debug('ECDH parameters: %r', items)
-    return dict(items)['e']
+    return dict(items)[b'e']
 
 
 def pkdecrypt(keygrip, conn):
@@ -85,18 +104,9 @@ def pkdecrypt(keygrip, conn):
     assert keyring.recvline(conn) == b'END'
     remote_pubkey = parse_ecdh(line)
 
-    user_id = os.environ['TREZOR_GPG_USER_ID']
-    local_pubkey = decode.load_public_key(
-        pubkey_bytes=keyring.export_public_key(user_id=user_id),
-        use_custom=True, ecdh=True)
-    pubkey, conn = encode.load_from_public_key(pubkey_dict=local_pubkey)
-    with contextlib.closing(conn):
-        assert pubkey.keygrip == binascii.unhexlify(keygrip)
-        shared_secret = conn.ecdh(remote_pubkey)
-
-    assert len(shared_secret) == 65
-    assert shared_secret[:1] == b'\x04'
-    return _serialize_point(shared_secret)
+    keygrip_bytes = binascii.unhexlify(keygrip)
+    with open_connection(keygrip_bytes) as conn:
+        return _serialize_point(conn.ecdh(remote_pubkey))
 
 
 def handle_connection(conn):
@@ -104,30 +114,36 @@ def handle_connection(conn):
     keygrip = None
     digest = None
     algo = None
-    version = keyring.gpg_version()
+    version = keyring.gpg_version()  # "Clone" existing GPG version
 
     keyring.sendline(conn, b'OK')
     for line in keyring.iterlines(conn):
-        parts = line.split(' ')
+        parts = line.split(b' ')
         command = parts[0]
         args = parts[1:]
-        if command in {'RESET', 'OPTION', 'HAVEKEY', 'SETKEYDESC'}:
+        if command in {b'RESET', b'OPTION', b'HAVEKEY', b'SETKEYDESC'}:
             pass  # reply with OK
-        elif command == 'GETINFO':
+        elif command == b'GETINFO':
             keyring.sendline(conn, b'D ' + version)
-        elif command == 'AGENT_ID':
-            keyring.sendline(conn, b'D TREZOR')
-        elif command in {'SIGKEY', 'SETKEY'}:
+        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 == 'SETHASH':
+        elif command == b'SETHASH':
             algo, digest = args
-        elif command == 'PKSIGN':
+        elif command == b'PKSIGN':
             sig = pksign(keygrip, digest, algo)
             keyring.sendline(conn, b'D ' + sig)
-        elif command == 'PKDECRYPT':
+        elif command == b'PKDECRYPT':
             sec = pkdecrypt(keygrip, conn)
             keyring.sendline(conn, b'D ' + sec)
-        elif command == 'BYE':
+        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
         else:
             log.error('unknown request: %r', line)

trezor_agent/gpg/decode.py

@@ -1,6 +1,5 @@
 """Decoders for GPG v2 data structures."""
 import base64
-import copy
 import functools
 import hashlib
 import io
@@ -53,39 +52,29 @@ def parse_mpis(s, n):
     return [parse_mpi(s) for _ in range(n)]
 
 
-def _parse_nist256p1_verifier(mpi):
+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)
-    vk = ecdsa.VerifyingKey.from_public_point(
+    return ecdsa.VerifyingKey.from_public_point(
         point=point, curve=ecdsa.curves.NIST256p,
         hashfunc=hashlib.sha256)
 
-    def _nist256p1_verify(signature, digest):
-        result = vk.verify_digest(signature=signature,
-                                  digest=digest,
-                                  sigdecode=lambda rs, order: rs)
-        log.debug('nist256p1 ECDSA signature is OK (%s)', result)
-    return _nist256p1_verify, vk
 
-
-def _parse_ed25519_verifier(mpi):
+def _parse_ed25519_pubkey(mpi):
     prefix, value = util.split_bits(mpi, 8, 256)
     assert prefix == 0x40
-    vk = ed25519.VerifyingKey(util.num2bytes(value, size=32))
-
-    def _ed25519_verify(signature, digest):
-        sig = b''.join(util.num2bytes(val, size=32)
-                       for val in signature)
-        result = vk.verify(sig, digest)
-        log.debug('ed25519 ECDSA signature is OK (%s)', result)
-    return _ed25519_verify, vk
+    return ed25519.VerifyingKey(util.num2bytes(value, size=32))
 
 
 SUPPORTED_CURVES = {
-    b'\x2A\x86\x48\xCE\x3D\x03\x01\x07': _parse_nist256p1_verifier,
-    b'\x2B\x06\x01\x04\x01\xDA\x47\x0F\x01': _parse_ed25519_verifier,
+    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}
@@ -168,11 +157,10 @@ def _parse_pubkey(stream, packet_type='pubkey'):
             oid_size = stream.readfmt('B')
             oid = stream.read(oid_size)
             assert oid in SUPPORTED_CURVES, util.hexlify(oid)
-            parser = SUPPORTED_CURVES[oid]
+            p['curve_oid'] = oid
 
             mpi = parse_mpi(stream)
             log.debug('mpi: %x (%d bits)', mpi, mpi.bit_length())
-            p['verifier'], p['verifying_key'] = parser(mpi)
             leftover = stream.read()
             if leftover:
                 leftover = io.BytesIO(leftover)
@@ -181,15 +169,18 @@ def _parse_pubkey(stream, packet_type='pubkey'):
                 size, = util.readfmt(leftover, 'B')
                 p['kdf'] = leftover.read(size)
                 assert not 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:
-            log.warning('DSA signatures are not verified')
-            parse_mpis(stream, n=4)
+            parse_mpis(stream, n=4)  # DSA keys are not supported
         elif p['algo'] == ELGAMAL_ALGO_ID:
-            log.warning('ElGamal signatures are not verified')
-            parse_mpis(stream, n=3)
+            parse_mpis(stream, n=3)  # ElGamal keys are not supported
         else:  # assume RSA
-            log.warning('RSA signatures are not verified')
-            parse_mpis(stream, n=2)
+            parse_mpis(stream, n=2)  # RSA keys are not supported
         assert not stream.read()
 
     # https://tools.ietf.org/html/rfc4880#section-12.2
@@ -280,28 +271,6 @@ def digest_packets(packets, hasher):
     return hasher.digest()
 
 
-def collect_packets(packets, types_to_collect):
-    """Collect specified packet types into their leading packet."""
-    packet = None
-    result = []
-    for p in packets:
-        if p['type'] in types_to_collect:
-            packet.setdefault(p['type'], []).append(p)
-        else:
-            packet = copy.deepcopy(p)
-            result.append(packet)
-    return result
-
-
-def parse_public_keys(stream):
-    """Parse GPG public key into hierarchy of packets."""
-    packets = list(parse_packets(stream))
-    packets = collect_packets(packets, {'signature'})
-    packets = collect_packets(packets, {'user_id', 'user_attribute'})
-    packets = collect_packets(packets, {'subkey'})
-    return packets
-
-
 HASH_ALGORITHMS = {
     1: 'md5',
     2: 'sha1',
@@ -313,42 +282,22 @@ HASH_ALGORITHMS = {
 }
 
 
-def load_public_key(pubkey_bytes, use_custom=False, ecdh=False):
-    """Parse and validate GPG public key from an input stream."""
+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))
-    pubkey, userid, signature = packets[:3]
-    packets = packets[3:]
+    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)
 
-    hash_alg = HASH_ALGORITHMS.get(signature['hash_alg'])
-    if hash_alg is not None:
-        digest = digest_packets(packets=[pubkey, userid, signature],
-                                hasher=hashlib.new(hash_alg))
-        assert signature['hash_prefix'] == digest[:2]
-
-    log.debug('loaded public key "%s"', userid['value'])
-    if hash_alg is not None and pubkey.get('verifier'):
-        verify_digest(pubkey=pubkey, digest=digest,
-                      signature=signature['sig'], label='GPG public key')
-    else:
-        log.warning('public key %s is not verified!',
-                    util.hexlify(pubkey['key_id']))
-
-    packet = pubkey
-    while use_custom:
-        if packet['type'] in ('pubkey', 'subkey') and signature['_is_custom']:
-            if ecdh == (packet['algo'] == protocol.ECDH_ALGO_ID):
-                log.debug('found custom %s', packet['type'])
-                break
-
-        while packets[1]['type'] != 'signature':
-            packets = packets[1:]
-        packet, signature = packets[:2]
-        packets = packets[2:]
-
-    packet['user_id'] = userid['value']
-    packet['_is_custom'] = signature['_is_custom']
-    return packet
+    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):
@@ -361,17 +310,6 @@ def load_signature(stream, original_data):
     return signature, digest
 
 
-def verify_digest(pubkey, digest, signature, label):
-    """Verify a digest signature from a specified public key."""
-    verifier = pubkey['verifier']
-    try:
-        verifier(signature, digest)
-        log.debug('%s is OK', label)
-    except ecdsa.keys.BadSignatureError:
-        log.error('Bad %s!', label)
-        raise ValueError('Invalid ECDSA signature for {}'.format(label))
-
-
 def remove_armor(armored_data):
     """Decode armored data into its binary form."""
     stream = io.BytesIO(armored_data)
@@ -380,11 +318,3 @@ def remove_armor(armored_data):
     payload, checksum = data[:-3], data[-3:]
     assert util.crc24(payload) == checksum
     return payload
-
-
-def verify(pubkey, signature, original_data):
-    """Verify correctness of public key and signature."""
-    stream = io.BytesIO(remove_armor(signature))
-    signature, digest = load_signature(stream, original_data)
-    verify_digest(pubkey=pubkey, digest=digest,
-                  signature=signature['sig'], label='GPG signature')

trezor_agent/gpg/device.py

@@ -0,0 +1,54 @@
+"""Device abstraction layer for GPG operations."""
+
+from .. import factory, formats, util
+
+
+class HardwareSigner(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.client_wrapper = factory.load()
+        self.identity = self.client_wrapper.identity_type()
+        self.identity.proto = 'gpg'
+        self.identity.host = user_id
+        self.curve_name = curve_name
+
+    def pubkey(self, ecdh=False):
+        """Return public key as VerifyingKey object."""
+        addr = util.get_bip32_address(identity=self.identity, ecdh=ecdh)
+        if ecdh:
+            curve_name = formats.get_ecdh_curve_name(self.curve_name)
+        else:
+            curve_name = self.curve_name
+        public_node = self.client_wrapper.connection.get_public_node(
+            n=addr, ecdsa_curve_name=curve_name)
+
+        return formats.decompress_pubkey(
+            pubkey=public_node.node.public_key,
+            curve_name=curve_name)
+
+    def sign(self, digest):
+        """Sign the digest and return a serialized signature."""
+        result = self.client_wrapper.connection.sign_identity(
+            identity=self.identity,
+            challenge_hidden=digest,
+            challenge_visual='',
+            ecdsa_curve_name=self.curve_name)
+        assert result.signature[:1] == b'\x00'
+        sig = result.signature[1:]
+        return (util.bytes2num(sig[:32]), util.bytes2num(sig[32:]))
+
+    def ecdh(self, pubkey):
+        """Derive shared secret using ECDH from remote public key."""
+        result = self.client_wrapper.connection.get_ecdh_session_key(
+            identity=self.identity,
+            peer_public_key=pubkey,
+            ecdsa_curve_name=formats.get_ecdh_curve_name(self.curve_name))
+        assert len(result.session_key) in {65, 33}  # NIST256 or Curve25519
+        assert result.session_key[:1] == b'\x04'
+        return result.session_key
+
+    def close(self):
+        """Close the connection to the device."""
+        self.client_wrapper.connection.close()

trezor_agent/gpg/encode.py

@@ -1,83 +1,13 @@
 """Create GPG ECDSA signatures and public keys using TREZOR device."""
+import io
 import logging
-import time
 
 from . import decode, keyring, protocol
-from .. import client, factory, formats, util
+from .. import util
 
 log = logging.getLogger(__name__)
 
 
-class HardwareSigner(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.client_wrapper = factory.load()
-        self.identity = self.client_wrapper.identity_type()
-        self.identity.proto = 'gpg'
-        self.identity.host = user_id
-        self.curve_name = curve_name
-
-    def pubkey(self, ecdh=False):
-        """Return public key as VerifyingKey object."""
-        addr = client.get_address(identity=self.identity, ecdh=ecdh)
-        public_node = self.client_wrapper.connection.get_public_node(
-            n=addr, ecdsa_curve_name=self.curve_name)
-
-        return formats.decompress_pubkey(
-            pubkey=public_node.node.public_key,
-            curve_name=self.curve_name)
-
-    def sign(self, digest):
-        """Sign the digest and return a serialized signature."""
-        result = self.client_wrapper.connection.sign_identity(
-            identity=self.identity,
-            challenge_hidden=digest,
-            challenge_visual='',
-            ecdsa_curve_name=self.curve_name)
-        assert result.signature[:1] == b'\x00'
-        sig = result.signature[1:]
-        return (util.bytes2num(sig[:32]), util.bytes2num(sig[32:]))
-
-    def ecdh(self, pubkey):
-        """Derive shared secret using ECDH from remote public key."""
-        result = self.client_wrapper.connection.get_ecdh_session_key(
-            identity=self.identity,
-            peer_public_key=pubkey,
-            ecdsa_curve_name=self.curve_name)
-        assert len(result.session_key) == 65
-        assert result.session_key[:1] == b'\x04'
-        return result.session_key
-
-    def close(self):
-        """Close the connection to the device."""
-        self.client_wrapper.connection.clear_session()
-        self.client_wrapper.connection.close()
-
-
-class AgentSigner(object):
-    """Sign messages and get public keys using gpg-agent tool."""
-
-    def __init__(self, user_id):
-        """Connect to the agent and retrieve required public key."""
-        self.sock = keyring.connect_to_agent()
-        self.keygrip = keyring.get_keygrip(user_id)
-
-    def sign(self, digest):
-        """Sign the digest and return an ECDSA/RSA/DSA signature."""
-        return keyring.sign_digest(sock=self.sock,
-                                   keygrip=self.keygrip, digest=digest)
-
-    def close(self):
-        """Close the connection to gpg-agent."""
-        self.sock.close()
-
-
-def _time_format(t):
-    return time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(t))
-
-
 def create_primary(user_id, pubkey, signer_func):
     """Export new primary GPG public key, ready for "gpg2 --import"."""
     pubkey_packet = protocol.packet(tag=6, blob=pubkey.data())
@@ -87,7 +17,6 @@ def create_primary(user_id, pubkey, signer_func):
     data_to_sign = (pubkey.data_to_hash() +
                     user_id_packet[:1] +
                     util.prefix_len('>L', user_id.encode('ascii')))
-    log.info('creating primary GPG key "%s"', user_id)
     hashed_subpackets = [
         protocol.subpacket_time(pubkey.created),  # signature time
         # https://tools.ietf.org/html/rfc4880#section-5.2.3.7
@@ -106,7 +35,6 @@ def create_primary(user_id, pubkey, signer_func):
         protocol.subpacket(16, pubkey.key_id()),  # issuer key id
         protocol.CUSTOM_SUBPACKET]
 
-    log.info('confirm signing with primary key')
     signature = protocol.make_signature(
         signer_func=signer_func,
         public_algo=pubkey.algo_id,
@@ -119,26 +47,26 @@ def create_primary(user_id, pubkey, signer_func):
     return pubkey_packet + user_id_packet + sign_packet
 
 
-def create_subkey(primary_bytes, pubkey, signer_func):
+def create_subkey(primary_bytes, subkey, signer_func, user_id=None):
     """Export new subkey to GPG primary key."""
-    subkey_packet = protocol.packet(tag=14, blob=pubkey.data())
-    primary = decode.load_public_key(primary_bytes)
-    log.info('adding subkey to primary GPG key "%s"', primary['user_id'])
-    data_to_sign = primary['_to_hash'] + pubkey.data_to_hash()
+    subkey_packet = protocol.packet(tag=14, blob=subkey.data())
+    packets = list(decode.parse_packets(io.BytesIO(primary_bytes)))
+    primary, user_id, signature = packets[:3]
 
-    if pubkey.ecdh:
+    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(pubkey.created)]  # signature time
+            protocol.subpacket_time(subkey.created)]  # signature time
         unhashed_subpackets = [
-            protocol.subpacket(16, pubkey.key_id())]  # issuer key id
-        log.info('confirm signing with new subkey')
+            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=pubkey.algo_id,
+            public_algo=subkey.algo_id,
             sig_type=0x19,
             hashed_subpackets=hashed_subpackets,
             unhashed_subpackets=unhashed_subpackets)
@@ -147,10 +75,10 @@ def create_subkey(primary_bytes, pubkey, signer_func):
 
     # Key flags: https://tools.ietf.org/html/rfc4880#section-5.2.3.21
     # (certify & sign)                   (encrypt)
-    flags = (2) if (not pubkey.ecdh) else (4 | 8)
+    flags = (2) if (not subkey.ecdh) else (4 | 8)
 
     hashed_subpackets = [
-        protocol.subpacket_time(pubkey.created),  # signature time
+        protocol.subpacket_time(subkey.created),  # signature time
         protocol.subpacket_byte(0x1B, flags)]
 
     unhashed_subpackets = []
@@ -159,9 +87,8 @@ def create_subkey(primary_bytes, pubkey, signer_func):
         unhashed_subpackets.append(protocol.subpacket(32, embedded_sig))
     unhashed_subpackets.append(protocol.CUSTOM_SUBPACKET)
 
-    log.info('confirm signing with primary key')
-    if not primary['_is_custom']:
-        signer_func = AgentSigner(primary['user_id']).sign
+    if not signature['_is_custom']:
+        signer_func = keyring.create_agent_signer(user_id['value'])
 
     signature = protocol.make_signature(
         signer_func=signer_func,
@@ -172,22 +99,3 @@ def create_subkey(primary_bytes, pubkey, signer_func):
         unhashed_subpackets=unhashed_subpackets)
     sign_packet = protocol.packet(tag=2, blob=signature)
     return primary_bytes + subkey_packet + sign_packet
-
-
-def load_from_public_key(pubkey_dict):
-    """Load correct public key from the device."""
-    user_id = pubkey_dict['user_id']
-    created = pubkey_dict['created']
-    curve_name = protocol.find_curve_by_algo_id(pubkey_dict['algo'])
-    assert curve_name in formats.SUPPORTED_CURVES
-    ecdh = (pubkey_dict['algo'] == protocol.ECDH_ALGO_ID)
-
-    conn = HardwareSigner(user_id, curve_name=curve_name)
-    pubkey = protocol.PublicKey(
-        curve_name=curve_name, created=created,
-        verifying_key=conn.pubkey(ecdh=ecdh), ecdh=ecdh)
-    assert pubkey.key_id() == pubkey_dict['key_id']
-    log.info('%s created at %s for "%s"',
-             pubkey, _time_format(pubkey.created), user_id)
-
-    return pubkey, conn

trezor_agent/gpg/keyring.py

@@ -1,4 +1,5 @@
 """Tools for doing signature using gpg-agent."""
+from __future__ import absolute_import, print_function, unicode_literals
 
 import binascii
 import io
@@ -15,15 +16,15 @@ 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('\n')
-    dirs = dict(line.split(':', 1) for line in lines)
-    return dirs['agent-socket']
+    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'])
+    sp.check_call(['gpg-connect-agent', '/bye'])  # Stop current gpg-agent
     sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
     sock.connect(sock_path)
     return sock
@@ -190,7 +191,7 @@ def get_keygrip(user_id, sp=subprocess):
 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).decode('ascii')
+    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'
 
@@ -203,3 +204,21 @@ def export_public_key(user_id, sp=subprocess):
         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

@@ -47,9 +47,22 @@ def subpacket_byte(subpacket_type, value):
     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 = [util.prefix_len('>B', item) for item in items]
+    prefixed = [subpacket_prefix_len(item) for item in items]
     return util.prefix_len('>H', b''.join(prefixed))
 
 
@@ -86,7 +99,8 @@ def _compute_keygrip(params):
     return hashlib.sha1(b''.join(parts)).digest()
 
 
-def _keygrip_nist256(vk):
+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()
@@ -103,7 +117,8 @@ def _keygrip_nist256(vk):
     ])
 
 
-def _keygrip_ed25519(vk):
+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
@@ -115,20 +130,39 @@ def _keygrip_ed25519(vk):
     ])
 
 
+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,
+        '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,
-    }
+        '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
@@ -136,14 +170,12 @@ ECDH_ALGO_ID = 18
 CUSTOM_SUBPACKET = subpacket(100, b'TREZOR-GPG')  # marks "our" pubkey
 
 
-def find_curve_by_algo_id(algo_id):
-    """Find curve name that matches a public key algorith ID."""
-    if algo_id == ECDH_ALGO_ID:
-        return formats.CURVE_NIST256
-
-    curve_name, = [name for name, info in SUPPORTED_CURVES.items()
-                   if info['algo_id'] == algo_id]
-    return curve_name
+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):
@@ -154,7 +186,7 @@ class PublicKey(object):
         self.curve_info = SUPPORTED_CURVES[curve_name]
         self.created = int(created)  # time since Epoch
         self.verifying_key = verifying_key
-        self.ecdh = ecdh
+        self.ecdh = bool(ecdh)
         if ecdh:
             self.algo_id = ECDH_ALGO_ID
             self.ecdh_packet = b'\x03\x01\x08\x07'

trezor_agent/gpg/tests/test_decode.py

@@ -1,11 +1,10 @@
 import glob
-import hashlib
 import io
 import os
 
 import pytest
 
-from .. import decode
+from .. import decode, protocol
 from ... import util
 
 
@@ -14,6 +13,15 @@ def test_subpackets():
     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
@@ -22,84 +30,6 @@ def test_mpi():
     assert decode.parse_mpis(util.Reader(s), n=2) == [0x123, 5]
 
 
-def assert_subdict(d, s):
-    for k, v in s.items():
-        assert d[k] == v
-
-
-def test_primary_nist256p1():
-    # pylint: disable=line-too-long
-    data = b'''-----BEGIN PGP PUBLIC KEY BLOCK-----
-Version: GnuPG v2
-
-mFIEV0hI1hMIKoZIzj0DAQcCAwTXY7aq01xMPSU7gTHU9B7Z2CFoCk1Y4WYb8Tiy
-hurvIZ5la6+UEgAKF9HXpQo0yE+HQOgufoLlCpdE7NoEUb+HtAd0ZXN0aW5niHYE
-ExMIABIFAldISNYCGwMCFQgCFgACF4AAFgkQTcCehfpEIPILZFRSRVpPUi1HUEeV
-3QEApHKmBkbLVZNpsB8q9mBzKytxnOHNB3QWDuoKJu/ERi4A/1wRGZ/B0BDazHck
-zpR9luXTKwMEl+mlZmwEFKZXBmir
-=oyj0
------END PGP PUBLIC KEY BLOCK-----
-'''
-    stream = io.BytesIO(decode.remove_armor(data))
-    pubkey, user_id, signature = list(decode.parse_packets(stream))
-    expected_pubkey = {
-        'created': 1464355030, 'type': 'pubkey', 'tag': 6,
-        'version': 4, 'algo': 19, 'key_id': b'M\xc0\x9e\x85\xfaD \xf2',
-        '_to_hash': b'\x99\x00R\x04WHH\xd6\x13\x08*\x86H\xce=\x03\x01\x07\x02\x03\x04\xd7c\xb6\xaa\xd3\\L=%;\x811\xd4\xf4\x1e\xd9\xd8!h\nMX\xe1f\x1b\xf18\xb2\x86\xea\xef!\x9eek\xaf\x94\x12\x00\n\x17\xd1\xd7\xa5\n4\xc8O\x87@\xe8.~\x82\xe5\n\x97D\xec\xda\x04Q\xbf\x87'  # nopep8
-    }
-    assert_subdict(pubkey, expected_pubkey)
-    point = pubkey['verifying_key'].pubkey.point
-    assert point.x(), point.y() == (
-        97423441028100245505102979561460969898742433559010922791700160771755342491425,
-        71644624850142103522769833619875243486871666152651730678601507641225861250951
-    )
-    assert_subdict(user_id, {
-        'tag': 13, 'type': 'user_id', 'value': b'testing',
-        '_to_hash': b'\xb4\x00\x00\x00\x07testing'
-    })
-    assert_subdict(signature, {
-        'pubkey_alg': 19, '_is_custom': True, 'hash_alg': 8, 'tag': 2,
-        'sig_type': 19, 'version': 4, 'type': 'signature', 'hash_prefix': b'\x95\xdd',
-        'sig': (74381873592149178031432444136130575481350858387410643140628758456112511206958,
-                41642995320462795718437755373080464775445470754419831653624197847615308982443),
-        'hashed_subpackets': [b'\x02WHH\xd6', b'\x1b\x03', b'\x15\x08', b'\x16\x00', b'\x17\x80'],
-        'unhashed_subpackets': [b'\x10M\xc0\x9e\x85\xfaD \xf2', b'dTREZOR-GPG'],
-        '_to_hash': b'\x04\x13\x13\x08\x00\x12\x05\x02WHH\xd6\x02\x1b\x03\x02\x15\x08\x02\x16\x00\x02\x17\x80\x04\xff\x00\x00\x00\x18'  # nopep8
-    })
-
-    digest = decode.digest_packets(packets=[pubkey, user_id, signature],
-                                   hasher=hashlib.sha256())
-    decode.verify_digest(pubkey=pubkey, digest=digest,
-                         signature=signature['sig'],
-                         label='GPG primary public key')
-
-    with pytest.raises(ValueError):
-        bad_digest = b'\x00' * len(digest)
-        decode.verify_digest(pubkey=pubkey, digest=bad_digest,
-                             signature=signature['sig'],
-                             label='GPG primary public key')
-
-    message = b'Hello, World!\n'
-    signature = b'''-----BEGIN PGP SIGNATURE-----
-Version: GnuPG v2
-
-iF4EABMIAAYFAldIlfQACgkQTcCehfpEIPKOUgD9FjaeWla4wOuDZ7P6fhkT5nZp
-KDQU0N5KmNwLlt2kwo4A/jQkBII2cI8tTqOVTLNRXXqIOsMf/fG4jKM/VOFc/01c
-=dC+z
------END PGP SIGNATURE-----
-'''
-    decode.verify(pubkey=pubkey, signature=signature, original_data=message)
-
-    pubkey = decode.load_public_key(pubkey_bytes=decode.remove_armor(data))
-    assert_subdict(pubkey, expected_pubkey)
-    assert_subdict(pubkey, {'user_id': b'testing'})
-
-    pubkey = decode.load_public_key(pubkey_bytes=decode.remove_armor(data),
-                                    use_custom=True)
-    assert_subdict(pubkey, expected_pubkey)
-    assert_subdict(pubkey, {'user_id': b'testing'})
-
-
 cwd = os.path.join(os.path.dirname(__file__))
 input_files = glob.glob(os.path.join(cwd, '*.gpg'))
 
@@ -111,5 +41,5 @@ def public_key_path(request):
 
 def test_gpg_files(public_key_path):  # pylint: disable=redefined-outer-name
     with open(public_key_path, 'rb') as f:
-        keys = decode.parse_public_keys(f)
-        assert len(keys) > 0
+        packets = list(decode.parse_packets(f))
+        assert len(packets) > 0

trezor_agent/gpg/tests/test_keyring.py

@@ -1,4 +1,5 @@
 import io
+
 import mock
 
 from .. import keyring

trezor_agent/gpg/tests/test_protocol.py

@@ -30,11 +30,6 @@ def test_mpi():
     assert protocol.mpi(0x123) == b'\x00\x09\x01\x23'
 
 
-def test_find():
-    assert protocol.find_curve_by_algo_id(19) == formats.CURVE_NIST256
-    assert protocol.find_curve_by_algo_id(22) == formats.CURVE_ED25519
-
-
 def test_armor():
     data = bytearray(range(256))
     assert protocol.armor(data, 'TEST') == '''-----BEGIN PGP TEST-----

trezor_agent/protocol.py

@@ -122,7 +122,7 @@ 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'])

trezor_agent/tests/test_client.py

@@ -87,8 +87,8 @@ def test_ssh_agent():
 
         def ssh_sign_identity(identity, challenge_hidden,
                               challenge_visual, ecdsa_curve_name):
-            assert (client.identity_to_string(identity) ==
-                    client.identity_to_string(ident))
+            assert (util.identity_to_string(identity) ==
+                    util.identity_to_string(ident))
             assert challenge_hidden == BLOB
             assert challenge_visual == ''
             assert ecdsa_curve_name == 'nist256p1'
@@ -133,4 +133,4 @@ def test_utils():
     identity.path = '/path'
 
     url = 'https://user@host:443/path'
-    assert client.identity_to_string(identity) == url
+    assert util.identity_to_string(identity) == url

trezor_agent/util.py

@@ -1,9 +1,14 @@
 """Various I/O and serialization utilities."""
 import binascii
 import contextlib
+import hashlib
 import io
+import logging
+import re
 import struct
 
+log = logging.getLogger(__name__)
+
 
 def send(conn, data):
     """Send data blob to connection socket."""
@@ -173,3 +178,61 @@ class Reader(object):
             yield
         finally:
             self._captured = None
+
+
+_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_bip32_address(identity, ecdh=False):
+    """Compute BIP32 derivation address according to SLIP-0013/0017."""
+    index = struct.pack('<L', identity.index)
+    addr = index + identity_to_string(identity).encode('ascii')
+    log.debug('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(recv(s, '<LLLL'))
+    return [(hardened | value) for value in address_n]
+
+
+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)