Merge branch 'which-fix'

libagent/gpg/__init__.py

@@ -129,8 +129,16 @@ def run_init(device_type, args):
     check_call(['mkdir', '-p', homedir])
     check_call(['chmod', '700', homedir])
 
-    agent_path = check_output(['which', '{}-gpg-agent'.format(device_name)])
-    agent_path = agent_path.strip()
+    agent_path = util.which('{}-gpg-agent'.format(device_name))
+
+    # Prepare GPG agent invocation script (to pass the PATH from environment).
+    with open(os.path.join(homedir, 'run-agent.sh'), 'w') as f:
+        f.write("""#!/bin/sh
+export PATH={0}
+{1} $*
+""".format(os.environ['PATH'], agent_path))
+    check_call(['chmod', 'u+x', f.name])
+    run_agent_script = f.name
 
     # Prepare GPG configuration file
     with open(os.path.join(homedir, 'gpg.conf'), 'w') as f:
@@ -138,7 +146,7 @@ def run_init(device_type, args):
 agent-program {0}
 personal-digest-preferences SHA512
 default-key \"{1}\"
-""".format(agent_path, args.user_id))
+""".format(run_agent_script, args.user_id))
 
     # Prepare GPG agent configuration file
     with open(os.path.join(homedir, 'gpg-agent.conf'), 'w') as f:

libagent/gpg/keyring.py

@@ -16,10 +16,11 @@ log = logging.getLogger(__name__)
 
 def get_agent_sock_path(env=None, sp=subprocess):
     """Parse gpgconf output to find out GPG agent UNIX socket path."""
-    output = sp.check_output(['gpgconf', '--list-dirs'], env=env)
+    args = [util.which('gpgconf'), '--list-dirs']
+    output = sp.check_output(args=args, env=env)
     lines = output.strip().split(b'\n')
     dirs = dict(line.split(b':', 1) for line in lines)
-    log.debug('gpgconf --list-dirs: %s', dirs)
+    log.debug('%s: %s', args, dirs)
     return dirs[b'agent-socket']
 
 
@@ -179,22 +180,23 @@ def sign_digest(sock, keygrip, digest, sp=subprocess, environ=None):
 
 def get_gnupg_components(sp=subprocess):
     """Parse GnuPG components' paths."""
-    output = sp.check_output(['gpgconf', '--list-components'])
+    output = sp.check_output([util.which('gpgconf'), '--list-components'])
     components = dict(re.findall('(.*):.*:(.*)', output.decode('ascii')))
     log.debug('gpgconf --list-components: %s', components)
     return components
 
 
+@util.memoize
 def get_gnupg_binary(sp=subprocess):
     """Starting GnuPG 2.2.x, the default installation uses `gpg`."""
     return get_gnupg_components(sp=sp)['gpg']
 
 
-def gpg_command(args, env=None, sp=subprocess):
+def gpg_command(args, env=None):
     """Prepare common GPG command line arguments."""
     if env is None:
         env = os.environ
-    cmd = [get_gnupg_binary(sp=sp)]
+    cmd = [get_gnupg_binary()]
     homedir = env.get('GNUPGHOME')
     if homedir:
         cmd.extend(['--homedir', homedir])
@@ -203,14 +205,14 @@ def gpg_command(args, env=None, sp=subprocess):
 
 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], sp=sp)
+    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'], sp=sp)
+    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'
@@ -218,7 +220,7 @@ def gpg_version(sp=subprocess):
 
 def export_public_key(user_id, env=None, sp=subprocess):
     """Export GPG public key for specified `user_id`."""
-    args = gpg_command(['--export', user_id], sp=sp)
+    args = gpg_command(['--export', user_id])
     result = sp.check_output(args=args, env=env)
     if not result:
         log.error('could not find public key %r in local GPG keyring', user_id)
@@ -228,7 +230,7 @@ def export_public_key(user_id, env=None, sp=subprocess):
 
 def export_public_keys(env=None, sp=subprocess):
     """Export all GPG public keys."""
-    args = gpg_command(['--export'], sp=sp)
+    args = gpg_command(['--export'])
     result = sp.check_output(args=args, env=env)
     if not result:
         raise KeyError('No GPG public keys found at env: {!r}'.format(env))

libagent/util.py

@@ -213,3 +213,19 @@ def memoize(func):
             return result
 
     return wrapper
+
+
+@memoize
+def which(cmd):
+    """Return full path to specified command, or raise OSError if missing."""
+    try:
+        # For Python 3
+        from shutil import which as _which
+    except ImportError:
+        # For Python 2
+        from backports.shutil_which import which as _which  # pylint: disable=relative-import
+    full_path = _which(cmd)
+    if full_path is None:
+        raise OSError('Cannot find {!r} in $PATH'.format(cmd))
+    log.debug('which %r => %r', cmd, full_path)
+    return full_path

setup.py

@@ -15,6 +15,7 @@ setup(
         'libagent.ssh'
     ],
     install_requires=[
+        'backports.shutil_which>=3.5.1',
         'ecdsa>=0.13',
         'ed25519>=1.4',
         'pymsgbox>=1.0.6',