Files
clinch/app/mailers/security_mailer.rb
Dan Milne 44892e3301 Make WebAuthn clone detection actually block, and fix false positives
Two problems with sign-count clone detection:

- suspicious_sign_count? flagged the case where both the stored and presented
  counts are 0. Most synced passkeys (Apple/Google) report 0 every time, so every
  legitimate sign-in was flagged — drowning real signals in noise. Per WebAuthn
  §6.1.1 a 0 counter means "no counter"; only flag when BOTH counts are non-zero
  and the new one does not advance.

- On a suspicious count the controller only logged a warning and then continued
  to authenticate and overwrite the stored counter. A cloned credential therefore
  worked indefinitely. webauthn_verify now rejects the sign-in (no session, no
  counter update) and emails the user via a new SecurityMailer#suspicious_passkey_used.

Tests cover the corrected classification (synced/first-use/normal vs equal/
decreasing) and the new alert email.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-06-11 20:28:38 +10:00

66 lines
2.5 KiB
Ruby

class SecurityMailer < ApplicationMailer
SUBJECT_PREFIX = "[Clinch security alert] ".freeze
def password_changed(user, ip:, user_agent:, occurred_at:)
assign_context(user, ip, user_agent, occurred_at)
mail subject: "#{SUBJECT_PREFIX}Your password was changed", to: user.email_address
end
def totp_disabled(user, ip:, user_agent:, occurred_at:)
assign_context(user, ip, user_agent, occurred_at)
mail subject: "#{SUBJECT_PREFIX}Two-factor authentication was disabled", to: user.email_address
end
def backup_codes_regenerated(user, ip:, user_agent:, occurred_at:)
assign_context(user, ip, user_agent, occurred_at)
mail subject: "#{SUBJECT_PREFIX}Two-factor backup codes were regenerated", to: user.email_address
end
def passkey_added(user, nickname:, ip:, user_agent:, occurred_at:)
assign_context(user, ip, user_agent, occurred_at)
@nickname = nickname
mail subject: "#{SUBJECT_PREFIX}A passkey was added to your account", to: user.email_address
end
def passkey_removed(user, nickname:, ip:, user_agent:, occurred_at:)
assign_context(user, ip, user_agent, occurred_at)
@nickname = nickname
mail subject: "#{SUBJECT_PREFIX}A passkey was removed from your account", to: user.email_address
end
def api_key_created(user, name:, ip:, user_agent:, occurred_at:)
assign_context(user, ip, user_agent, occurred_at)
@api_key_name = name
mail subject: "#{SUBJECT_PREFIX}An API key was created on your account", to: user.email_address
end
def api_key_revoked(user, name:, ip:, user_agent:, occurred_at:)
assign_context(user, ip, user_agent, occurred_at)
@api_key_name = name
mail subject: "#{SUBJECT_PREFIX}An API key was revoked on your account", to: user.email_address
end
def suspicious_passkey_used(user, nickname:, ip:, user_agent:, occurred_at:)
assign_context(user, ip, user_agent, occurred_at)
@nickname = nickname
mail subject: "#{SUBJECT_PREFIX}A passkey sign-in was blocked", to: user.email_address
end
def email_address_changed(user, recipient:, old_email:, new_email:, ip:, user_agent:, occurred_at:)
assign_context(user, ip, user_agent, occurred_at)
@recipient = recipient
@old_email = old_email
@new_email = new_email
mail subject: "#{SUBJECT_PREFIX}Your account email address was changed", to: recipient
end
private
def assign_context(user, ip, user_agent, occurred_at)
@user = user
@ip = ip
@user_agent = user_agent
@occurred_at = occurred_at
end
end