Module: Mpp::Server::Verify

Extended by:
T::Sig
Defined in:
lib/mpp/server/verify.rb

Constant Summary collapse

DEFAULT_EXPIRES_MINUTES =
5

Class Method Summary collapse

Class Method Details

.body_digest_matches?(echo, body) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'lib/mpp/server/verify.rb', line 213

def body_digest_matches?(echo, body)
  if body.nil?
    return echo.digest.nil?
  end
  return false unless echo.digest

  Mpp::BodyDigest.verify(T.must(echo.digest), body)
end

.create_challenge(method, intent_name, request, realm, secret_key, description = nil, meta = nil, expires = nil, body = nil) ⇒ Object



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# File 'lib/mpp/server/verify.rb', line 189

def create_challenge(method, intent_name, request, realm, secret_key,
  description = nil, meta = nil, expires = nil, body = nil)
  expires = nil if expires && !expires.is_a?(String)

  if expires.nil?
    expires_dt = Time.now.utc + (DEFAULT_EXPIRES_MINUTES * 60)
    expires = expires_dt.strftime("%Y-%m-%dT%H:%M:%S.%LZ")
  end
  digest = body.nil? ? nil : Mpp::BodyDigest.compute(body)

  Mpp::Challenge.create(
    secret_key: secret_key,
    realm: realm,
    method: method,
    intent: intent_name,
    request: request,
    expires: expires,
    digest: digest,
    description: description,
    meta: meta
  )
end

.emit_challenge_created(dispatcher:, challenge:, credential:, error:, method:, request:) ⇒ Object



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# File 'lib/mpp/server/verify.rb', line 232

def emit_challenge_created(dispatcher:, challenge:, credential:, error:, method:, request:)
  return unless dispatcher&.has_handlers?(Mpp::Events::CHALLENGE_CREATED)

  payload = {
    challenge: challenge,
    method: method,
    request: request
  }
  payload[:credential] = credential unless credential.nil?
  payload[:error] = error unless error.nil?
  dispatcher.emit(Mpp::Events::CHALLENGE_CREATED, payload)
end

.emit_payment_failed(dispatcher:, challenge:, credential:, error:, method:, request:, retry_challenge: nil, submitted_challenge: nil) ⇒ Object



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# File 'lib/mpp/server/verify.rb', line 246

def emit_payment_failed(dispatcher:, challenge:, credential:, error:, method:, request:, retry_challenge: nil, submitted_challenge: nil)
  return unless dispatcher.has_handlers?(Mpp::Events::PAYMENT_FAILED)

  payload = {
    challenge: challenge,
    credential: credential,
    error: error,
    method: method,
    request: request
  }
  payload[:retry_challenge] = retry_challenge unless retry_challenge.nil?
  payload[:submitted_challenge] =  unless .nil?
  dispatcher.emit(Mpp::Events::PAYMENT_FAILED, payload)
end

.emit_payment_success(dispatcher:, challenge:, credential:, method:, receipt:, request:) ⇒ Object



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# File 'lib/mpp/server/verify.rb', line 262

def emit_payment_success(dispatcher:, challenge:, credential:, method:, receipt:, request:)
  return unless dispatcher.has_handlers?(Mpp::Events::PAYMENT_SUCCESS)

  dispatcher.emit(Mpp::Events::PAYMENT_SUCCESS, {
    challenge: challenge,
    credential: credential,
    method: method,
    receipt: receipt,
    request: request
  })
end

.extract_payment_scheme(header) ⇒ Object



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# File 'lib/mpp/server/verify.rb', line 223

def extract_payment_scheme(header)
  header.split(",").each do |scheme|
    scheme = scheme.strip
    return scheme if scheme.downcase.start_with?("payment ")
  end
  nil
end

.verify_or_challenge(authorization:, intent:, request:, realm:, secret_key:, method: nil, description: nil, meta: nil, expires: nil, events: nil, body: nil) ⇒ Object



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# File 'lib/mpp/server/verify.rb', line 19

def verify_or_challenge(authorization:, intent:, request:, realm:, secret_key:,
  method: nil, description: nil, meta: nil, expires: nil, events: nil, body: nil)
  method_name = method || "tempo"
  request = Mpp::Units.transform_units(request)
  dispatcher = events
  events_enabled = dispatcher&.has_handlers?
  method_context = events_enabled ? {name: method_name, intent: intent.name} : nil

  new_challenge = Kernel.lambda { |credential = nil, error = nil,  = nil|
    challenge = create_challenge(method_name, intent.name, request, realm, secret_key, description, meta, expires, body)
    if error && dispatcher&.has_handlers?(Mpp::Events::PAYMENT_FAILED)
      emit_payment_failed(
        dispatcher: dispatcher,
        challenge: challenge,
        credential: credential,
        error: error,
        method: T.must(method_context),
        request: request,
        retry_challenge: challenge,
        submitted_challenge: 
      )
    end
    if dispatcher&.has_handlers?(Mpp::Events::CHALLENGE_CREATED)
      emit_challenge_created(
        dispatcher: dispatcher,
        challenge: challenge,
        credential: credential,
        error: error,
        method: T.must(method_context),
        request: request
      )
    end
    challenge
  }

  return new_challenge.call if authorization.nil?

  payment_scheme = extract_payment_scheme(authorization)
  return new_challenge.call if payment_scheme.nil?

  begin
    credential = Mpp::Credential.from_authorization(payment_scheme)
  rescue Mpp::ParseError => e
    return new_challenge.call(nil, Mpp::MalformedCredentialError.new(reason: e.message))
  end

  # Stateless challenge verification
  echo = credential.challenge
  begin
    echo_request = echo.request.empty? ? {} : Mpp::Parsing.b64_decode(echo.request)
    echo_opaque = (echo.opaque && !T.must(echo.opaque).empty?) ? Mpp::Parsing.b64_decode(echo.opaque) : nil
  rescue Mpp::ParseError => e
    return new_challenge.call(credential, Mpp::MalformedCredentialError.new(reason: e.message), echo)
  end

  expected_id = Mpp.generate_challenge_id(
    secret_key: secret_key,
    realm: echo.realm,
    method: echo.method,
    intent: echo.intent,
    request: echo_request,
    expires: echo.expires,
    digest: echo.digest,
    opaque: echo_opaque
  )
  unless Mpp.secure_compare(echo.id, expected_id)
    return new_challenge.call(
      credential,
      Mpp::InvalidChallengeError.new(challenge_id: echo.id, reason: "challenge id mismatch"),
      echo
    )
  end

  # Assert echoed fields match server's values
  unless echo.realm == realm && echo.method == method_name && echo.intent == intent.name
    return new_challenge.call(
      credential,
      Mpp::InvalidChallengeError.new(challenge_id: echo.id, reason: "challenge binding mismatch"),
      echo
    )
  end

  # Assert echoed request matches server's current request
  unless echo_request == request
    return new_challenge.call(
      credential,
      Mpp::InvalidChallengeError.new(challenge_id: echo.id, reason: "request mismatch"),
      echo
    )
  end

  unless echo_opaque == meta
    return new_challenge.call(
      credential,
      Mpp::InvalidChallengeError.new(challenge_id: echo.id, reason: "metadata mismatch"),
      echo
    )
  end

  unless body_digest_matches?(echo, body)
    return new_challenge.call(
      credential,
      Mpp::InvalidChallengeError.new(challenge_id: echo.id, reason: "body digest mismatch"),
      echo
    )
  end

  # Verify echoed request parameters match endpoint's expected request
  request.each do |key, value|
    unless echo_request[key] == value
      return new_challenge.call(
        credential,
        Mpp::InvalidChallengeError.new(challenge_id: echo.id, reason: "request field #{key} mismatch"),
        echo
      )
    end
  end

  # Enforce challenge expiry - fail closed
  unless echo.expires
    return new_challenge.call(
      credential,
      Mpp::InvalidChallengeError.new(challenge_id: echo.id, reason: "missing expiry"),
      echo
    )
  end

  begin
    expires_dt = Time.iso8601(T.must(echo.expires).gsub("Z", "+00:00"))
  rescue ArgumentError
    return new_challenge.call(
      credential,
      Mpp::InvalidChallengeError.new(challenge_id: echo.id, reason: "invalid expiry"),
      echo
    )
  end
  if expires_dt < Time.now.utc
    return new_challenge.call(credential, Mpp::PaymentExpiredError.new(expires: echo.expires), echo)
  end

  begin
    receipt = intent.verify(credential, request)
  rescue => e
    if dispatcher&.has_handlers?(Mpp::Events::PAYMENT_FAILED)
      emit_payment_failed(
        dispatcher: dispatcher,
        challenge: echo,
        credential: credential,
        error: e,
        method: T.must(method_context),
        request: request,
        submitted_challenge: echo
      )
    end
    Kernel.raise
  end
  if dispatcher&.has_handlers?(Mpp::Events::PAYMENT_SUCCESS)
    emit_payment_success(
      dispatcher: dispatcher,
      challenge: echo,
      credential: credential,
      method: T.must(method_context),
      receipt: receipt,
      request: request
    )
  end
  [credential, receipt]
end