Admins configure one mail server; each staff member gets their own mailbox login. Read, reply and compose against real IMAP/SMTP. IMAP and SMTP are raw TCP, so none of this can run in a browser — every operation is a TanStack Start server function. mail.functions.ts ships to the client bundle, so imapflow/nodemailer/mailparser and the crypto helpers are imported inside handlers, never at the top level. Verified that Nitro inlines all three into .output/server/_libs, since the Docker runner stage copies only .output and has no node_modules. Note this ties the app to the Node deployment: the default local build targets Cloudflare Workers, which cannot open IMAP sockets. Credential handling, since a mailbox password grants full read and send access to someone's mail: - user_mailboxes has RLS enabled, no policies, and SELECT revoked from anon and authenticated. Verified: teacher and admin both see zero rows and no ciphertext; only service_role can read it. The revoke is belt and braces — Supabase's default privileges had granted SELECT, leaving the table one stray policy away from leaking. - Passwords are sealed with AES-256-GCM using MAIL_CRED_KEY from .env.secret, so a database dump alone opens nothing. GCM also makes tampering fail the auth tag instead of decrypting to garbage. - Provisioning verifies credentials against the live IMAP server before storing them, so typos surface at setup rather than as a broken inbox. Message bodies render as plain text; sender HTML is never injected, which would execute sender-controlled markup and leak read receipts via tracking pixels. Mailboxes are limited to admins and teachers. Students are excluded deliberately — external mail for minors carries archiving, monitoring and consent obligations that should be chosen, not inherited. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
64 lines
3.1 KiB
SQL
64 lines
3.1 KiB
SQL
-- Embedded mail: one shared IMAP/SMTP server configured by admins, with a
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-- per-user mailbox login.
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--
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-- Threat model drives the shape here. A mailbox password grants full read and
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-- send access to someone's email, so:
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--
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-- * user_mailboxes has RLS enabled and NO policies at all. Nothing reachable
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-- from a browser can read it — not even the mailbox owner, and not admins.
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-- Every access goes through server functions using the service role, the
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-- same pattern intake_tokens uses.
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-- * The password is never stored as plaintext. It is sealed with AES-256-GCM
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-- using MAIL_CRED_KEY from .env.secret, so a database dump alone is not
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-- enough to open anyone's mail.
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-- * The IMAP/SMTP *host* settings are not secret, so admins may read those
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-- directly to populate the setup form.
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CREATE TABLE IF NOT EXISTS public.mail_server_settings (
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-- Single-row table: the school has one mail server.
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id BOOLEAN PRIMARY KEY DEFAULT TRUE CHECK (id = TRUE),
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imap_host TEXT NOT NULL,
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imap_port INT NOT NULL DEFAULT 993,
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imap_secure BOOLEAN NOT NULL DEFAULT TRUE, -- implicit TLS on connect
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smtp_host TEXT NOT NULL,
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smtp_port INT NOT NULL DEFAULT 587,
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smtp_secure BOOLEAN NOT NULL DEFAULT FALSE, -- false = STARTTLS upgrade
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updated_by UUID REFERENCES auth.users(id),
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updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
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);
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GRANT SELECT ON public.mail_server_settings TO authenticated;
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GRANT ALL ON public.mail_server_settings TO service_role;
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ALTER TABLE public.mail_server_settings ENABLE ROW LEVEL SECURITY;
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-- Host/port are operational config, not secrets. Admins read them to fill in
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-- the setup form; writes go through a server function so they can be validated
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-- against a live login first.
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CREATE POLICY "mail settings admin read" ON public.mail_server_settings FOR SELECT TO authenticated
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USING (public.current_user_has_role('admin'));
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CREATE TABLE IF NOT EXISTS public.user_mailboxes (
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user_id UUID PRIMARY KEY REFERENCES auth.users(id) ON DELETE CASCADE,
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email TEXT NOT NULL,
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-- AES-256-GCM sealed mailbox password. Never returned to any client.
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secret_ciphertext TEXT NOT NULL,
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secret_iv TEXT NOT NULL,
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secret_tag TEXT NOT NULL,
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last_verified_at TIMESTAMPTZ,
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created_by UUID REFERENCES auth.users(id),
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created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
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updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
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);
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CREATE INDEX IF NOT EXISTS idx_user_mailboxes_email ON public.user_mailboxes(email);
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GRANT ALL ON public.user_mailboxes TO service_role;
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ALTER TABLE public.user_mailboxes ENABLE ROW LEVEL SECURITY;
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-- Deliberately no policies and no grant to `authenticated`: credentials must
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-- never be reachable from the browser under any role.
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DROP TRIGGER IF EXISTS trg_mail_settings_upd ON public.mail_server_settings;
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CREATE TRIGGER trg_mail_settings_upd BEFORE UPDATE ON public.mail_server_settings
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FOR EACH ROW EXECUTE FUNCTION public.set_updated_at();
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DROP TRIGGER IF EXISTS trg_user_mailboxes_upd ON public.user_mailboxes;
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CREATE TRIGGER trg_user_mailboxes_upd BEFORE UPDATE ON public.user_mailboxes
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FOR EACH ROW EXECUTE FUNCTION public.set_updated_at();
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