sydent/scripts/casefold_db.py

#!/usr/bin/env python
# Copyright 2021 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import argparse
import json
import os
import sqlite3
import sys
from typing import Any, Dict, List, Tuple

import signedjson.sign

from sydent.config import SydentConfig
from sydent.sydent import Sydent, parse_config_file
from sydent.util import json_decoder
from sydent.util.emailutils import sendEmail
from sydent.util.hash import sha256_and_url_safe_base64
from tests.utils import ResolvingMemoryReactorClock


def calculate_lookup_hash(sydent, address):
    cur = sydent.db.cursor()
    pepper_result = cur.execute("SELECT lookup_pepper from hashing_metadata")
    pepper = pepper_result.fetchone()[0]
    combo = "%s %s %s" % (address, "email", pepper)
    lookup_hash = sha256_and_url_safe_base64(combo)
    return lookup_hash


def update_local_associations(
    sydent: Sydent, db: sqlite3.Connection, send_email: bool, dry_run: bool
):
    """Update the DB table local_threepid_associations so that all stored
    emails are casefolded, and any duplicate mxid's associated with the
    given email are deleted.

    :return: None
    """
    cur = db.cursor()

    res = cur.execute(
        "SELECT address, mxid FROM local_threepid_associations WHERE medium = 'email'"
        "ORDER BY ts DESC"
    )

    # a dict that associates an email address with correspoinding mxids and lookup hashes
    associations: Dict[str, List[Tuple[str, str, str]]] = {}

    # iterate through selected associations, casefold email, rehash it, and add to
    # associations dict
    for address, mxid in res.fetchall():
        casefold_address = address.casefold()

        # rehash email since hashes are case-sensitive
        lookup_hash = calculate_lookup_hash(sydent, casefold_address)

        if casefold_address in associations:
            associations[casefold_address].append((address, mxid, lookup_hash))
        else:
            associations[casefold_address] = [(address, mxid, lookup_hash)]

    # list of arguments to update db with
    db_update_args: List[Tuple[str, str, str, str]] = []

    # list of mxids to delete
    to_delete: List[Tuple[str]] = []

    # list of mxids to send emails to letting them know the mxid has been deleted
    mxids: List[Tuple[str, str]] = []

    for casefold_address, assoc_tuples in associations.items():
        db_update_args.append(
            (
                casefold_address,
                assoc_tuples[0][2],
                assoc_tuples[0][0],
                assoc_tuples[0][1],
            )
        )

        if len(assoc_tuples) > 1:
            # Iterate over all associations except for the first one, since we've already
            # processed it.
            for address, mxid, _ in assoc_tuples[1:]:
                to_delete.append((address,))
                mxids.append((mxid, address))

    # iterate through the mxids and send email, let's only send one email per mxid
    if send_email and not dry_run:
        for mxid, address in mxids:
            processed_mxids = []

            if mxid in processed_mxids:
                continue
            else:
                if sydent.config.email.template is None:
                    templateFile = sydent.get_branded_template(
                        None,
                        "migration_template.eml",
                        ("email", "email.template"),
                    )
                else:
                    templateFile = sydent.config.email.template

                sendEmail(
                    sydent,
                    templateFile,
                    address,
                    {"mxid": "mxid", "subject_header_value": "MatrixID Update"},
                )
                processed_mxids.append(mxid)

    print(
        f"{len(to_delete)} rows to delete, {len(db_update_args)} rows to update in local_threepid_associations"
    )

    if not dry_run:
        if len(to_delete) > 0:
            cur.executemany(
                "DELETE FROM local_threepid_associations WHERE address = ?", to_delete
            )

        if len(db_update_args) > 0:
            cur.executemany(
                "UPDATE local_threepid_associations SET address = ?, lookup_hash = ? WHERE address = ? AND mxid = ?",
                db_update_args,
            )

        # We've finished updating the database, committing the transaction.
        db.commit()


def update_global_associations(
    sydent: Sydent, db: sqlite3.Connection, send_email: bool, dry_run: bool
):
    """Update the DB table global_threepid_associations so that all stored
    emails are casefolded, the signed association is re-signed and any duplicate
    mxid's associated with the given email are deleted.

    :return: None
    """

    # get every row where the local server is origin server and medium is email
    origin_server = sydent.config.general.server_name
    medium = "email"

    cur = db.cursor()
    res = cur.execute(
        "SELECT address, mxid, sgAssoc FROM global_threepid_associations WHERE medium = ?"
        "AND originServer = ? ORDER BY ts DESC",
        (medium, origin_server),
    )

    # dict that stores email address with mxid, email address, lookup hash, and
    # signed association
    associations: Dict[str, List[Tuple[str, str, str, str]]] = {}

    # iterate through selected associations, casefold email, rehash it, re-sign the
    # associations and add to associations dict
    for address, mxid, sg_assoc in res.fetchall():
        casefold_address = address.casefold()

        # rehash the email since hash functions are case-sensitive
        lookup_hash = calculate_lookup_hash(sydent, casefold_address)

        # update signed associations with new casefolded address and re-sign
        sg_assoc = json_decoder.decode(sg_assoc)
        sg_assoc["address"] = address.casefold()
        sg_assoc = json.dumps(
            signedjson.sign.sign_json(
                sg_assoc, sydent.config.general.server_name, sydent.keyring.ed25519
            )
        )

        if casefold_address in associations:
            associations[casefold_address].append(
                (address, mxid, lookup_hash, sg_assoc)
            )
        else:
            associations[casefold_address] = [(address, mxid, lookup_hash, sg_assoc)]

    # list of arguments to update db with
    db_update_args: List[Tuple[Any, str, str, str, str]] = []

    # list of mxids to delete
    to_delete: List[Tuple[str]] = []

    for casefold_address, assoc_tuples in associations.items():
        db_update_args.append(
            (
                casefold_address,
                assoc_tuples[0][2],
                assoc_tuples[0][3],
                assoc_tuples[0][0],
                assoc_tuples[0][1],
            )
        )

        if len(assoc_tuples) > 1:
            # Iterate over all associations except for the first one, since we've already
            # processed it.
            for address, mxid, _, _ in assoc_tuples[1:]:
                to_delete.append((address,))

    print(
        f"{len(to_delete)} rows to delete, {len(db_update_args)} rows to update in global_threepid_associations"
    )

    if not dry_run:
        if len(to_delete) > 0:
            cur.executemany(
                "DELETE FROM global_threepid_associations WHERE address = ?", to_delete
            )

        if len(db_update_args) > 0:
            cur.executemany(
                "UPDATE global_threepid_associations SET address = ?, lookup_hash = ?, sgAssoc = ? WHERE address = ? AND mxid = ?",
                db_update_args,
            )

        db.commit()


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Casefold email addresses in database")
    parser.add_argument(
        "--no-email", action="store_true", help="run script but do not send emails"
    )
    parser.add_argument(
        "--dry-run",
        action="store_true",
        help="run script but do not send emails or alter database",
    )

    parser.add_argument("config_path", help="path to the sydent configuration file")

    args = parser.parse_args()

    # if the path the user gives us doesn't work, find it for them
    if not os.path.exists(args.config_path):
        print(f"The config file '{args.config_path}' does not exist.")
        sys.exit(1)

    config = parse_config_file(args.config_path)

    sydent_config = SydentConfig()
    sydent_config.parse_from_config_parser(config)

    reactor = ResolvingMemoryReactorClock()
    sydent = Sydent(config, sydent_config, reactor, False)

    update_global_associations(sydent, sydent.db, not args.no_email, args.dry_run)
    update_local_associations(sydent, sydent.db, not args.no_email, args.dry_run)