from flask import render_template, redirect, url_for, flash, request from flask_login import login_required, current_user from itsdangerous import TimestampSigner, SignatureExpired from app.config import ( DISABLE_ALIAS_SUFFIX, ALIAS_DOMAINS, CUSTOM_ALIAS_SECRET, ) from app.dashboard.base import dashboard_bp from app.email_utils import email_belongs_to_alias_domains from app.extensions import db from app.log import LOG from app.models import Alias, CustomDomain, DeletedAlias, Mailbox, User, AliasMailbox from app.utils import convert_to_id, random_word, word_exist signer = TimestampSigner(CUSTOM_ALIAS_SECRET) def available_suffixes(user: User) -> [bool, str, str]: """Return (is_custom_domain, alias-suffix, time-signed alias-suffix)""" user_custom_domains = [cd.domain for cd in user.verified_custom_domains()] # List of (is_custom_domain, alias-suffix, time-signed alias-suffix) suffixes = [] # put custom domain first for alias_domain in user_custom_domains: suffix = "@" + alias_domain suffixes.append((True, suffix, signer.sign(suffix).decode())) # then default domain for domain in ALIAS_DOMAINS: suffix = ("" if DISABLE_ALIAS_SUFFIX else "." + random_word()) + "@" + domain suffixes.append((False, suffix, signer.sign(suffix).decode())) return suffixes @dashboard_bp.route("/custom_alias", methods=["GET", "POST"]) @login_required def custom_alias(): # check if user has not exceeded the alias quota if not current_user.can_create_new_alias(): # notify admin LOG.error("user %s tries to create custom alias", current_user) flash( "You have reached free plan limit, please upgrade to create new aliases", "warning", ) return redirect(url_for("dashboard.index")) user_custom_domains = [cd.domain for cd in current_user.verified_custom_domains()] # List of (is_custom_domain, alias-suffix, time-signed alias-suffix) suffixes = available_suffixes(current_user) mailboxes = current_user.mailboxes() if request.method == "POST": alias_prefix = request.form.get("prefix") signed_suffix = request.form.get("suffix") mailbox_ids = request.form.getlist("mailboxes") alias_note = request.form.get("note") # check if mailbox is not tempered with mailboxes = [] for mailbox_id in mailbox_ids: mailbox = Mailbox.get(mailbox_id) if ( not mailbox or mailbox.user_id != current_user.id or not mailbox.verified ): flash("Something went wrong, please retry", "warning") return redirect(url_for("dashboard.custom_alias")) mailboxes.append(mailbox) if not mailboxes: flash("At least one mailbox must be selected", "error") return redirect(url_for("dashboard.custom_alias")) # hypothesis: user will click on the button in the 600 secs try: alias_suffix = signer.unsign(signed_suffix, max_age=600).decode() except SignatureExpired: LOG.error("Alias creation time expired for %s", current_user) flash("Alias creation time is expired, please retry", "warning") return redirect(url_for("dashboard.custom_alias")) except Exception: LOG.error("Alias suffix is tampered, user %s", current_user) flash("Unknown error, refresh the page", "error") return redirect(url_for("dashboard.custom_alias")) if verify_prefix_suffix(current_user, alias_prefix, alias_suffix): full_alias = alias_prefix + alias_suffix if Alias.get_by(email=full_alias) or DeletedAlias.get_by(email=full_alias): LOG.d("full alias already used %s", full_alias) flash( f"Alias {full_alias} already exists, please choose another one", "warning", ) else: alias = Alias.create( user_id=current_user.id, email=full_alias, note=alias_note, mailbox_id=mailboxes[0].id, ) db.session.flush() for i in range(1, len(mailboxes)): AliasMailbox.create( alias_id=alias.id, mailbox_id=mailboxes[i].id, ) # get the custom_domain_id if alias is created with a custom domain if alias_suffix.startswith("@"): alias_domain = alias_suffix[1:] domain = CustomDomain.get_by(domain=alias_domain) LOG.d("Set alias %s domain to %s", full_alias, domain) alias.custom_domain_id = domain.id db.session.commit() flash(f"Alias {full_alias} has been created", "success") return redirect(url_for("dashboard.index", highlight_alias_id=alias.id)) # only happen if the request has been "hacked" else: flash("something went wrong", "warning") return render_template( "dashboard/custom_alias.html", user_custom_domains=user_custom_domains, suffixes=suffixes, mailboxes=mailboxes, ) def verify_prefix_suffix(user, alias_prefix, alias_suffix) -> bool: """verify if user could create an alias with the given prefix and suffix""" if not alias_prefix or not alias_suffix: # should be caught on frontend return False user_custom_domains = [cd.domain for cd in user.verified_custom_domains()] alias_prefix = alias_prefix.strip() alias_prefix = convert_to_id(alias_prefix) # make sure alias_suffix is either .random_word@simplelogin.co or @my-domain.com alias_suffix = alias_suffix.strip() if alias_suffix.startswith("@"): alias_domain = alias_suffix[1:] # alias_domain can be either custom_domain or if DISABLE_ALIAS_SUFFIX, one of the default ALIAS_DOMAINS if DISABLE_ALIAS_SUFFIX: if ( alias_domain not in user_custom_domains and alias_domain not in ALIAS_DOMAINS ): LOG.error("wrong alias suffix %s, user %s", alias_suffix, user) return False else: if alias_domain not in user_custom_domains: LOG.error("wrong alias suffix %s, user %s", alias_suffix, user) return False else: if not alias_suffix.startswith("."): LOG.error("User %s submits a wrong alias suffix %s", user, alias_suffix) return False full_alias = alias_prefix + alias_suffix if not email_belongs_to_alias_domains(full_alias): LOG.error( "Alias suffix should end with one of the alias domains %s", user, alias_suffix, ) return False random_word_part = alias_suffix[1 : alias_suffix.find("@")] if not word_exist(random_word_part): LOG.error( "alias suffix %s needs to start with a random word, user %s", alias_suffix, user, ) return False return True