epicyon/blocking.py

__filename__ = "blocking.py"
__author__ = "Bob Mottram"
__license__ = "AGPL3+"
__version__ = "1.1.0"
__maintainer__ = "Bob Mottram"
__email__ = "bob@freedombone.net"
__status__ = "Production"

import os
from utils import removeIdEnding
from utils import isEvil
from utils import locatePost
from utils import evilIncarnate
from utils import getDomainFromActor
from utils import getNicknameFromActor


def addGlobalBlock(baseDir: str,
                   blockNickname: str, blockDomain: str) -> bool:
    """Global block which applies to all accounts
    """
    blockingFilename = baseDir + '/accounts/blocking.txt'
    if not blockNickname.startswith('#'):
        # is the handle already blocked?
        blockHandle = blockNickname + '@' + blockDomain
        if os.path.isfile(blockingFilename):
            if blockHandle in open(blockingFilename).read():
                return False
        # block an account handle or domain
        blockFile = open(blockingFilename, "a+")
        if blockFile:
            blockFile.write(blockHandle + '\n')
            blockFile.close()
    else:
        blockHashtag = blockNickname
        # is the hashtag already blocked?
        if os.path.isfile(blockingFilename):
            if blockHashtag + '\n' in open(blockingFilename).read():
                return False
        # block a hashtag
        blockFile = open(blockingFilename, "a+")
        if blockFile:
            blockFile.write(blockHashtag + '\n')
            blockFile.close()
    return True


def addBlock(baseDir: str, nickname: str, domain: str,
             blockNickname: str, blockDomain: str) -> bool:
    """Block the given account
    """
    if ':' in domain:
        domain = domain.split(':')[0]
    blockingFilename = baseDir + '/accounts/' + \
        nickname + '@' + domain + '/blocking.txt'
    blockHandle = blockNickname + '@' + blockDomain
    if os.path.isfile(blockingFilename):
        if blockHandle in open(blockingFilename).read():
            return False
    blockFile = open(blockingFilename, "a+")
    blockFile.write(blockHandle + '\n')
    blockFile.close()
    return True


def removeGlobalBlock(baseDir: str,
                      unblockNickname: str,
                      unblockDomain: str) -> bool:
    """Unblock the given global block
    """
    unblockingFilename = baseDir + '/accounts/blocking.txt'
    if not unblockNickname.startswith('#'):
        unblockHandle = unblockNickname + '@' + unblockDomain
        if os.path.isfile(unblockingFilename):
            if unblockHandle in open(unblockingFilename).read():
                with open(unblockingFilename, 'r') as fp:
                    with open(unblockingFilename + '.new', 'w+') as fpnew:
                        for line in fp:
                            handle = line.replace('\n', '').replace('\r', '')
                            if unblockHandle not in line:
                                fpnew.write(handle + '\n')
                if os.path.isfile(unblockingFilename + '.new'):
                    os.rename(unblockingFilename + '.new', unblockingFilename)
                    return True
    else:
        unblockHashtag = unblockNickname
        if os.path.isfile(unblockingFilename):
            if unblockHashtag + '\n' in open(unblockingFilename).read():
                with open(unblockingFilename, 'r') as fp:
                    with open(unblockingFilename + '.new', 'w+') as fpnew:
                        for line in fp:
                            blockLine = \
                                line.replace('\n', '').replace('\r', '')
                            if unblockHashtag not in line:
                                fpnew.write(blockLine + '\n')
                if os.path.isfile(unblockingFilename + '.new'):
                    os.rename(unblockingFilename + '.new', unblockingFilename)
                    return True
    return False


def removeBlock(baseDir: str, nickname: str, domain: str,
                unblockNickname: str, unblockDomain: str) -> bool:
    """Unblock the given account
    """
    if ':' in domain:
        domain = domain.split(':')[0]
    unblockingFilename = baseDir + '/accounts/' + \
        nickname + '@' + domain + '/blocking.txt'
    unblockHandle = unblockNickname + '@' + unblockDomain
    if os.path.isfile(unblockingFilename):
        if unblockHandle in open(unblockingFilename).read():
            with open(unblockingFilename, 'r') as fp:
                with open(unblockingFilename + '.new', 'w+') as fpnew:
                    for line in fp:
                        handle = line.replace('\n', '').replace('\r', '')
                        if unblockHandle not in line:
                            fpnew.write(handle + '\n')
            if os.path.isfile(unblockingFilename + '.new'):
                os.rename(unblockingFilename + '.new', unblockingFilename)
                return True
    return False


def isBlockedHashtag(baseDir: str, hashtag: str) -> bool:
    """Is the given hashtag blocked?
    """
    # avoid very long hashtags
    if len(hashtag) > 32:
        return True
    globalBlockingFilename = baseDir + '/accounts/blocking.txt'
    if os.path.isfile(globalBlockingFilename):
        hashtag = hashtag.strip('\n').strip('\r')
        if not hashtag.startswith('#'):
            hashtag = '#' + hashtag
        if hashtag + '\n' in open(globalBlockingFilename).read():
            return True
    return False


def getDomainBlocklist(baseDir: str) -> str:
    """Returns all globally blocked domains as a string
    This can be used for fast matching to mitigate flooding
    """
    blockedStr = ''

    evilDomains = evilIncarnate()
    for evil in evilDomains:
        blockedStr += evil + '\n'

    globalBlockingFilename = baseDir + '/accounts/blocking.txt'
    if not os.path.isfile(globalBlockingFilename):
        return blockedStr
    with open(globalBlockingFilename, 'r') as fpBlocked:
        blockedStr += fpBlocked.read()
    return blockedStr


def isBlockedDomain(baseDir: str, domain: str) -> bool:
    """Is the given domain blocked?
    """
    if '.' not in domain:
        return False

    if isEvil(domain):
        return True

    # by checking a shorter version we can thwart adversaries
    # who constantly change their subdomain
    sections = domain.split('.')
    noOfSections = len(sections)
    shortDomain = None
    if noOfSections > 2:
        shortDomain = domain[noOfSections-2] + '.' + domain[noOfSections-1]

    globalBlockingFilename = baseDir + '/accounts/blocking.txt'
    if os.path.isfile(globalBlockingFilename):
        with open(globalBlockingFilename, 'r') as fpBlocked:
            blockedStr = fpBlocked.read()
            if '*@' + domain in blockedStr:
                return True
            if shortDomain:
                if '*@' + shortDomain in blockedStr:
                    return True
    return False


def isBlocked(baseDir: str, nickname: str, domain: str,
              blockNickname: str, blockDomain: str) -> bool:
    """Is the given nickname blocked?
    """
    if isEvil(blockDomain):
        return True
    globalBlockingFilename = baseDir + '/accounts/blocking.txt'
    if os.path.isfile(globalBlockingFilename):
        if '*@' + blockDomain in open(globalBlockingFilename).read():
            return True
        if blockNickname:
            blockHandle = blockNickname + '@' + blockDomain
            if blockHandle in open(globalBlockingFilename).read():
                return True
    allowFilename = baseDir + '/accounts/' + \
        nickname + '@' + domain + '/allowedinstances.txt'
    if os.path.isfile(allowFilename):
        if blockDomain not in open(allowFilename).read():
            return True
    blockingFilename = baseDir + '/accounts/' + \
        nickname + '@' + domain + '/blocking.txt'
    if os.path.isfile(blockingFilename):
        if '*@' + blockDomain in open(blockingFilename).read():
            return True
        if blockNickname:
            blockHandle = blockNickname + '@' + blockDomain
            if blockHandle in open(blockingFilename).read():
                return True
    return False


def outboxBlock(baseDir: str, httpPrefix: str,
                nickname: str, domain: str, port: int,
                messageJson: {}, debug: bool) -> None:
    """ When a block request is received by the outbox from c2s
    """
    if not messageJson.get('type'):
        if debug:
            print('DEBUG: block - no type')
        return
    if not messageJson['type'] == 'Block':
        if debug:
            print('DEBUG: not a block')
        return
    if not messageJson.get('object'):
        if debug:
            print('DEBUG: no object in block')
        return
    if not isinstance(messageJson['object'], str):
        if debug:
            print('DEBUG: block object is not string')
        return
    if debug:
        print('DEBUG: c2s block request arrived in outbox')

    messageId = removeIdEnding(messageJson['object'])
    if '/statuses/' not in messageId:
        if debug:
            print('DEBUG: c2s block object is not a status')
        return
    if '/users/' not in messageId and \
       '/accounts/' not in messageId and \
       '/channel/' not in messageId and \
       '/profile/' not in messageId:
        if debug:
            print('DEBUG: c2s block object has no nickname')
        return
    if ':' in domain:
        domain = domain.split(':')[0]
    postFilename = locatePost(baseDir, nickname, domain, messageId)
    if not postFilename:
        if debug:
            print('DEBUG: c2s block post not found in inbox or outbox')
            print(messageId)
        return
    nicknameBlocked = getNicknameFromActor(messageJson['object'])
    if not nicknameBlocked:
        print('WARN: unable to find nickname in ' + messageJson['object'])
        return
    domainBlocked, portBlocked = getDomainFromActor(messageJson['object'])
    domainBlockedFull = domainBlocked
    if portBlocked:
        if portBlocked != 80 and portBlocked != 443:
            if ':' not in domainBlocked:
                domainBlockedFull = domainBlocked + ':' + str(portBlocked)

    addBlock(baseDir, nickname, domain,
             nicknameBlocked, domainBlockedFull)

    if debug:
        print('DEBUG: post blocked via c2s - ' + postFilename)


def outboxUndoBlock(baseDir: str, httpPrefix: str,
                    nickname: str, domain: str, port: int,
                    messageJson: {}, debug: bool) -> None:
    """ When an undo block request is received by the outbox from c2s
    """
    if not messageJson.get('type'):
        if debug:
            print('DEBUG: undo block - no type')
        return
    if not messageJson['type'] == 'Undo':
        if debug:
            print('DEBUG: not an undo block')
        return
    if not messageJson.get('object'):
        if debug:
            print('DEBUG: no object in undo block')
        return
    if not isinstance(messageJson['object'], dict):
        if debug:
            print('DEBUG: undo block object is not string')
        return

    if not messageJson['object'].get('type'):
        if debug:
            print('DEBUG: undo block - no type')
        return
    if not messageJson['object']['type'] == 'Block':
        if debug:
            print('DEBUG: not an undo block')
        return
    if not messageJson['object'].get('object'):
        if debug:
            print('DEBUG: no object in undo block')
        return
    if not isinstance(messageJson['object']['object'], str):
        if debug:
            print('DEBUG: undo block object is not string')
        return
    if debug:
        print('DEBUG: c2s undo block request arrived in outbox')

    messageId = removeIdEnding(messageJson['object']['object'])
    if '/statuses/' not in messageId:
        if debug:
            print('DEBUG: c2s undo block object is not a status')
        return
    if '/users/' not in messageId and \
       '/accounts/' not in messageId and \
       '/channel/' not in messageId and \
       '/profile/' not in messageId:
        if debug:
            print('DEBUG: c2s undo block object has no nickname')
        return
    if ':' in domain:
        domain = domain.split(':')[0]
    postFilename = locatePost(baseDir, nickname, domain, messageId)
    if not postFilename:
        if debug:
            print('DEBUG: c2s undo block post not found in inbox or outbox')
            print(messageId)
        return
    nicknameBlocked = getNicknameFromActor(messageJson['object']['object'])
    if not nicknameBlocked:
        print('WARN: unable to find nickname in ' +
              messageJson['object']['object'])
        return
    domainObject = messageJson['object']['object']
    domainBlocked, portBlocked = getDomainFromActor(domainObject)
    domainBlockedFull = domainBlocked
    if portBlocked:
        if portBlocked != 80 and portBlocked != 443:
            if ':' not in domainBlocked:
                domainBlockedFull = domainBlocked + ':' + str(portBlocked)

    removeBlock(baseDir, nickname, domain,
                nicknameBlocked, domainBlockedFull)
    if debug:
        print('DEBUG: post undo blocked via c2s - ' + postFilename)