| 1 | # GNU MediaGoblin -- federated, autonomous media hosting |
| 2 | # Copyright (C) 2011, 2012 MediaGoblin contributors. See AUTHORS. |
| 3 | # |
| 4 | # This program is free software: you can redistribute it and/or modify |
| 5 | # it under the terms of the GNU Affero General Public License as published by |
| 6 | # the Free Software Foundation, either version 3 of the License, or |
| 7 | # (at your option) any later version. |
| 8 | # |
| 9 | # This program is distributed in the hope that it will be useful, |
| 10 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | # GNU Affero General Public License for more details. |
| 13 | # |
| 14 | # You should have received a copy of the GNU Affero General Public License |
| 15 | # along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 16 | import bcrypt |
| 17 | import random |
| 18 | |
| 19 | import six |
| 20 | |
| 21 | from mediagoblin import mg_globals |
| 22 | from mediagoblin.tools.crypto import get_timed_signer_url |
| 23 | from mediagoblin.tools.mail import send_email |
| 24 | from mediagoblin.tools.template import render_template |
| 25 | |
| 26 | |
| 27 | def bcrypt_check_password(raw_pass, stored_hash, extra_salt=None): |
| 28 | """ |
| 29 | Check to see if this password matches. |
| 30 | |
| 31 | Args: |
| 32 | - raw_pass: user submitted password to check for authenticity. |
| 33 | - stored_hash: The hash of the raw password (and possibly extra |
| 34 | salt) to check against |
| 35 | - extra_salt: (optional) If this password is with stored with a |
| 36 | non-database extra salt (probably in the config file) for extra |
| 37 | security, factor this into the check. |
| 38 | |
| 39 | Returns: |
| 40 | True or False depending on success. |
| 41 | """ |
| 42 | if extra_salt: |
| 43 | raw_pass = u"%s:%s" % (extra_salt, raw_pass) |
| 44 | |
| 45 | hashed_pass = bcrypt.hashpw(raw_pass.encode('utf-8'), stored_hash) |
| 46 | |
| 47 | # Reduce risk of timing attacks by hashing again with a random |
| 48 | # number (thx to zooko on this advice, which I hopefully |
| 49 | # incorporated right.) |
| 50 | # |
| 51 | # See also: |
| 52 | rand_salt = bcrypt.gensalt(5) |
| 53 | randplus_stored_hash = bcrypt.hashpw(stored_hash, rand_salt) |
| 54 | randplus_hashed_pass = bcrypt.hashpw(hashed_pass, rand_salt) |
| 55 | |
| 56 | return randplus_stored_hash == randplus_hashed_pass |
| 57 | |
| 58 | |
| 59 | def bcrypt_gen_password_hash(raw_pass, extra_salt=None): |
| 60 | """ |
| 61 | Generate a salt for this new password. |
| 62 | |
| 63 | Args: |
| 64 | - raw_pass: user submitted password |
| 65 | - extra_salt: (optional) If this password is with stored with a |
| 66 | non-database extra salt |
| 67 | """ |
| 68 | if extra_salt: |
| 69 | raw_pass = u"%s:%s" % (extra_salt, raw_pass) |
| 70 | |
| 71 | return six.text_type( |
| 72 | bcrypt.hashpw(raw_pass.encode('utf-8'), bcrypt.gensalt())) |
| 73 | |
| 74 | |
| 75 | def fake_login_attempt(): |
| 76 | """ |
| 77 | Pretend we're trying to login. |
| 78 | |
| 79 | Nothing actually happens here, we're just trying to take up some |
| 80 | time, approximately the same amount of time as |
| 81 | bcrypt_check_password, so as to avoid figuring out what users are |
| 82 | on the system by intentionally faking logins a bunch of times. |
| 83 | """ |
| 84 | rand_salt = bcrypt.gensalt(5) |
| 85 | |
| 86 | hashed_pass = bcrypt.hashpw(str(random.random()), rand_salt) |
| 87 | |
| 88 | randplus_stored_hash = bcrypt.hashpw(str(random.random()), rand_salt) |
| 89 | randplus_hashed_pass = bcrypt.hashpw(hashed_pass, rand_salt) |
| 90 | |
| 91 | randplus_stored_hash == randplus_hashed_pass |
| 92 | |
| 93 | |
| 94 | EMAIL_FP_VERIFICATION_TEMPLATE = ( |
| 95 | u"{uri}?" |
| 96 | u"token={fp_verification_key}") |
| 97 | |
| 98 | |
| 99 | def send_fp_verification_email(user, request): |
| 100 | """ |
| 101 | Send the verification email to users to change their password. |
| 102 | |
| 103 | Args: |
| 104 | - user: a user object |
| 105 | - request: the request |
| 106 | """ |
| 107 | fp_verification_key = get_timed_signer_url('mail_verification_token') \ |
| 108 | .dumps(user.id) |
| 109 | |
| 110 | rendered_email = render_template( |
| 111 | request, 'mediagoblin/plugins/basic_auth/fp_verification_email.txt', |
| 112 | {'username': user.username, |
| 113 | 'verification_url': EMAIL_FP_VERIFICATION_TEMPLATE.format( |
| 114 | uri=request.urlgen('mediagoblin.plugins.basic_auth.verify_forgot_password', |
| 115 | qualified=True), |
| 116 | fp_verification_key=fp_verification_key)}) |
| 117 | |
| 118 | # TODO: There is no error handling in place |
| 119 | send_email( |
| 120 | mg_globals.app_config['email_sender_address'], |
| 121 | [user.email], |
| 122 | 'GNU MediaGoblin - Change forgotten password!', |
| 123 | rendered_email) |