[#64] Adds Keychain-based Authentication

Squashed commit of the following:

commit 0eb23aa87c264152716933e03827f040742e6d70
Author: Adam Coddington <me@adamcoddington.net>
Date:   Sat Feb 20 14:21:48 2016 -0800

    Updating readme to reflect updated flow.

commit 840268e2db6093b5cb573c6a3e71204bf5b08b48
Author: Adam Coddington <me@adamcoddington.net>
Date:   Sat Feb 20 14:18:39 2016 -0800

    Dropping python 2.6 support workaround.

commit 9dcbd460482c2925bda490be2be884a2a2526062
Author: Adam Coddington <me@adamcoddington.net>
Date:   Sat Feb 20 14:18:00 2016 -0800

    Adding additional behavior at @torarnv's request.

commit 6c711bb12beea7c792b5d386203373423b6e56e2
Author: Adam Coddington <me@adamcoddington.net>
Date:   Sat Jan 23 15:08:29 2016 -0800

    Workaround for obsolete versions of Python 2.

commit b0765b7b6bf9974348061043da9a110c6bd7d985
Author: Adam Coddington <me@adamcoddington.net>
Date:   Sat Jan 23 14:56:53 2016 -0800

    Style changes to avoid line length overage.

commit 4decc576432ef23edae01b9621f2689b4f3c6c84
Author: Adam Coddington <me@adamcoddington.net>
Date:   Sat Jan 23 14:01:27 2016 -0800

    Adding documentation; also adding --delete-from-keyring command-line option.

commit a6b0224e93a8bc9159cf06ba5792a384f7fbb060
Author: Adam Coddington <me@adamcoddington.net>
Date:   Sat Jan 23 13:44:09 2016 -0800

    Adding functionality allowing authentication using iCloud passwords stored in the system keychain.

    Adds the following new command-line options:

    * `--password-interactive`: Allows you to specify your password
      interactively rather than typing it into the command-line.
    * `--store-in-keychain`: Allows you to store the password in use in the
      system keychain.

    If no password is specified when instantiating `PyiCloudService` or when
    using the command-line utility (via either `--password-interactive` or
    `--password`), the system keychain will be queried for a stored
    password, and an exception will be raised if one was not found.

commit 4ba03fb02d51673dfb7183dde49ab4c0bec4afb3
Author: Adam Coddington <me@adamcoddington.net>
Date:   Sat Jan 23 13:43:39 2016 -0800

    Removing unused imports.

README.rst

@@ -15,13 +15,27 @@ At its core, PyiCloud connects to iCloud using your username and password, then
 Authentication
 ==============
 
-Authentication is as simple as passing your username and password to the ``PyiCloudService`` class:
+Authentication without using a saved password is as simple as passing your username and password to the ``PyiCloudService`` class:
 
 >>> from pyicloud import PyiCloudService
 >>> api = PyiCloudService('jappleseed@apple.com', 'password')
 
 In the event that the username/password combination is invalid, a ``PyiCloudFailedLoginException`` exception is thrown.
 
+You can also store your password in the system keyring using the command-line tool:
+
+>>> icloud --username=jappleseed@apple.com
+ICloud Password for jappleseed@apple.com:
+Save password in keyring? (y/N)
+
+If you have stored a password in the keyring, you will not be required to provide a password when interacting with the command-line tool or instantiating the ``PyiCloudService`` class for the username you stored the password for.
+
+>>> api = PyiCloudService('jappleseed@apple.com')
+
+If you would like to delete a password stored in your system keyring, you can clear a stored password using the ``--delete-from-keyring`` command-line option:
+
+>>> icloud --username=jappleseed@apple.com --delete-from-keyring
+
 =======
 Devices
 =======

pyicloud/base.py

@@ -1,10 +1,8 @@
 import six
-import copy
 import uuid
 import hashlib
 import json
 import logging
-import pickle
 import requests
 import sys
 import tempfile
@@ -19,6 +17,7 @@ from pyicloud.services import (
     ContactsService,
     RemindersService
 )
+from pyicloud.utils import get_password_from_keyring
 
 if six.PY3:
     import http.cookiejar as cookielib
@@ -39,7 +38,12 @@ class PyiCloudService(object):
         pyicloud = PyiCloudService('username@apple.com', 'password')
         pyicloud.iphone.location()
     """
-    def __init__(self, apple_id, password, cookie_directory=None, verify=True):
+    def __init__(
+        self, apple_id, password=None, cookie_directory=None, verify=True
+    ):
+        if password is None:
+            password = get_password_from_keyring(apple_id)
+
         self.discovery = None
         self.client_id = str(uuid.uuid1()).upper()
         self.user = {'apple_id': apple_id, 'password': password}

pyicloud/cmdline.py

@@ -9,7 +9,10 @@ import argparse
 import pickle
 import sys
 
+from click import confirm
+
 import pyicloud
+from . import utils
 
 
 DEVICE_ERROR = (
@@ -52,7 +55,25 @@ def main(args=None):
         action="store",
         dest="password",
         default="",
-        help="Apple ID Password to Use",
+        help=(
+            "Apple ID Password to Use; if unspecified, password will be "
+            "fetched from the system keyring."
+        )
+    )
+    parser.add_argument(
+        "-n",
+        "--non-interactive",
+        action="store_false",
+        dest="interactive",
+        default=True,
+        help="Disable interactive prompts."
+    )
+    parser.add_argument(
+        "--delete-from-keyring",
+        action="store_true",
+        dest="delete_from_keyring",
+        default=False,
+        help="Delete stored password in system keyring for this username.",
     )
     parser.add_argument(
         "--list",
@@ -152,17 +173,57 @@ def main(args=None):
     )
 
     command_line = parser.parse_args(args)
-    if not command_line.username or not command_line.password:
-        parser.error('No username or password supplied')
 
-    from pyicloud import PyiCloudService
+    username = command_line.username
-    try:
+    password = command_line.password
-        api = PyiCloudService(
+
-            command_line.username.strip(),
+    if username and command_line.delete_from_keyring:
-            command_line.password.strip()
+        utils.delete_password_in_keyring(username)
+
+    failure_count = 0
+    while True:
+        # Which password we use is determined by your username, so we
+        # do need to check for this first and separately.
+        if not username:
+            parser.error('No username supplied')
+
+        if not password:
+            password = utils.get_password(
+                username,
+                interactive=command_line.interactive
             )
+
+        if not password:
+            parser.error('No password supplied')
+
+        try:
+            api = pyicloud.PyiCloudService(
+                username.strip(),
+                password.strip()
+            )
+            if (
+                not utils.password_exists_in_keyring(username) and
+                command_line.interactive and
+                confirm("Save password in keyring? ")
+            ):
+                utils.store_password_in_keyring(username, password)
+            break
         except pyicloud.exceptions.PyiCloudFailedLoginException:
-        raise RuntimeError('Bad username or password')
+            # If they have a stored password; we just used it and
+            # it did not work; let's delete it if there is one.
+            if utils.password_exists_in_keyring(username):
+                utils.delete_password_in_keyring(username)
+
+            message = "Bad username or password for {username}".format(
+                username=username,
+            )
+            password = None
+
+            failure_count += 1
+            if failure_count >= 3:
+                raise RuntimeError(message)
+
+            print(message, file=sys.stderr)
 
     for dev in api.devices:
         if (

pyicloud/exceptions.py

@@ -1,8 +1,15 @@
 
-
+class PyiCloudException(Exception):
-class PyiCloudNoDevicesException(Exception):
     pass
 
 
-class PyiCloudFailedLoginException(Exception):
+class PyiCloudNoDevicesException(PyiCloudException):
+    pass
+
+
+class PyiCloudFailedLoginException(PyiCloudException):
+    pass
+
+
+class NoStoredPasswordAvailable(PyiCloudException):
     pass

pyicloud/utils.py

@@ -0,0 +1,63 @@
+import getpass
+import keyring
+
+from .exceptions import NoStoredPasswordAvailable
+
+
+KEYRING_SYSTEM = 'pyicloud://icloud-password'
+
+
+def get_password(username, interactive=True):
+    try:
+        return get_password_from_keyring(username)
+    except NoStoredPasswordAvailable:
+        if not interactive:
+            raise
+
+        return getpass.getpass(
+            'ICloud Password for {username}: '.format(
+                username=username,
+            )
+        )
+
+
+def password_exists_in_keyring(username):
+    try:
+        get_password_from_keyring(username)
+    except NoStoredPasswordAvailable:
+        return False
+
+    return True
+
+
+def get_password_from_keyring(username):
+    result = keyring.get_password(
+        KEYRING_SYSTEM,
+        username
+    )
+    if result is None:
+        raise NoStoredPasswordAvailable(
+            "No pyicloud password for {username} could be found "
+            "in the system keychain.  Use the `--store-in-keyring` "
+            "command-line option for storing a password for this "
+            "username.".format(
+                username=username,
+            )
+        )
+
+    return result
+
+
+def store_password_in_keyring(username, password):
+    return keyring.set_password(
+        KEYRING_SYSTEM,
+        username,
+        password,
+    )
+
+
+def delete_password_in_keyring(username):
+    return keyring.delete_password(
+        KEYRING_SYSTEM,
+        username,
+    )

requirements.txt

@@ -1,4 +1,7 @@
 requests>=1.2
+keyring>=8.0,<9.0
+keyrings.alt>=1.0,<2.0
+click>=6.0,<7.0
 six
 pytz
 certifi