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package smtp
import (
"io"
"github.com/emersion/go-sasl"
)
var (
ErrAuthFailed = &SMTPError{
Code: 535,
EnhancedCode: EnhancedCode{5, 7, 8},
Message: "Authentication failed",
}
ErrAuthRequired = &SMTPError{
Code: 502,
EnhancedCode: EnhancedCode{5, 7, 0},
Message: "Please authenticate first",
}
ErrAuthUnsupported = &SMTPError{
Code: 502,
EnhancedCode: EnhancedCode{5, 7, 0},
Message: "Authentication not supported",
}
ErrAuthUnknownMechanism = &SMTPError{
Code: 504,
EnhancedCode: EnhancedCode{5, 7, 4},
Message: "Unsupported authentication mechanism",
}
)
// A SMTP server backend.
type Backend interface {
NewSession(c *Conn) (Session, error)
}
// BackendFunc is an adapter to allow the use of an ordinary function as a
// Backend.
type BackendFunc func(c *Conn) (Session, error)
var _ Backend = (BackendFunc)(nil)
// NewSession calls f(c).
func (f BackendFunc) NewSession(c *Conn) (Session, error) {
return f(c)
}
// Session is used by servers to respond to an SMTP client.
//
// The methods are called when the remote client issues the matching command.
type Session interface {
// Discard currently processed message.
Reset()
// Free all resources associated with session.
Logout() error
// Set return path for currently processed message.
Mail(from string, opts *MailOptions) error
// Add recipient for currently processed message.
Rcpt(to string, opts *RcptOptions) error
// Set currently processed message contents and send it.
//
// r must be consumed before Data returns.
Data(r io.Reader) error
}
// LMTPSession is an add-on interface for Session. It can be implemented by
// LMTP servers to provide extra functionality.
type LMTPSession interface {
Session
// LMTPData is the LMTP-specific version of Data method.
// It can be optionally implemented by the backend to provide
// per-recipient status information when it is used over LMTP
// protocol.
//
// LMTPData implementation sets status information using passed
// StatusCollector by calling SetStatus once per each AddRcpt
// call, even if AddRcpt was called multiple times with
// the same argument. SetStatus must not be called after
// LMTPData returns.
//
// Return value of LMTPData itself is used as a status for
// recipients that got no status set before using StatusCollector.
LMTPData(r io.Reader, status StatusCollector) error
}
// StatusCollector allows a backend to provide per-recipient status
// information.
type StatusCollector interface {
SetStatus(rcptTo string, err error)
}
// AuthSession is an add-on interface for Session. It provides support for the
// AUTH extension.
type AuthSession interface {
Session
AuthMechanisms() []string
Auth(mech string) (sasl.Server, error)
}
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