direct

type Attachment ¶

type Attachment struct {
	Name     string
	MimeType string
	Content  []byte
}

Attachment is one part of a Direct message.

type Checker ¶ added in v0.1.19

type Checker struct {
	Anchors *x509.CertPool
	// Now is the time certificates are checked at; time.Now when nil.
	Now func() time.Time
	// Client fetches issuers and revocation lists; nil means one that refuses the cloud metadata address (egress).
	Client *http.Client
	// contains filtered or unexported fields
}

Checker decides whether a certificate found for a recipient may be encrypted to: it must chain to a trust anchor, fetching intermediate issuers named by its Authority Information Access extension when the chain is not complete, and it must not be revoked on its issuers' certificate revocation lists. Both are what the Direct Applicability Statement (4.2.2) asks for and what ONC's certificate discovery tool tests (D17, D18).

Revocation fails open: a list that cannot be fetched or read does not stop delivery, because a CRL server that is down would otherwise stop all Direct mail to everyone the authority issued for. A certificate listed as revoked, on a list its issuer signed, is always refused.

func (k *Checker) Check(ctx context.Context, c *x509.Certificate) error

type Disposition ¶

type Disposition struct {
	Kind, OriginalMessageID string
}

Disposition is an MDN's report.

type Message ¶

type Message struct {
	From, Subject string
	To            []string
	Text          string
	Attachments   []Attachment
	MessageID     string
	Date          time.Time
	// DispositionNotification asks the recipient for an MDN (the Direct Implementation Guide for Delivery Notification).
	DispositionNotification bool
}

Message is a Direct message before it is protected, or after it is opened.

func MDN(received *Opened, ourAddress, kind string) Message

type Opened ¶

type Opened struct {
	Message
	// Signer is the certificate that signed it, checked to a trust anchor.
	Signer *x509.Certificate
	// SignerAddress is the Direct address (or domain) the signer's certificate is for.
	SignerAddress string
	// XDM is the documents and metadata when an attachment is an XDM package.
	XDM []XDMDocument
	// MDN is the disposition notification when the message is one: its kind (processed, dispatched, failed) and the
	// Message-ID it is about.
	MDN *Disposition
}

Opened is a received message after decryption and signature checking.

func Open(raw []byte, keys []cms.KeyPair, anchors *x509.CertPool) (*Opened, error)

type Receiver ¶

type Receiver struct {
	Hostname string
	// Accept says whether mail for an address is taken.
	Accept func(rcpt string) bool
	// Deliver is given each message; an error refuses it.
	Deliver func(ctx context.Context, from string, to []string, raw []byte) error
	TLS     *tls.Config
	// RequireTLS refuses MAIL before STARTTLS.
	RequireTLS bool
	MaxBytes   int64
	Log        *slog.Logger
}

Receiver is the SMTP server a HISP delivers a Direct address's mail to: the Direct "edge" side of SMTP. It accepts mail only for the addresses it holds certificates for, requires STARTTLS before MAIL when it has a certificate (a Direct message is encrypted end to end, and the hop is protected as well), and hands each message to Deliver. A message Deliver refuses is refused at DATA with the reason, so the HISP keeps it and reports it.

func (r *Receiver) Serve(ln net.Listener) error

type XDMDocument ¶

type XDMDocument struct {
	Name, MimeType, Title, PatientID, UniqueID, TypeCode string
	Content                                              []byte
}

XDMDocument is one document from an XDM package, with what its metadata says.

func ReadXDM(zipped []byte) ([]XDMDocument, error)