Initial commit

vendor/github.com/emersion/go-sasl/sasl.go

@@ -0,0 +1,45 @@
+// Library for Simple Authentication and Security Layer (SASL) defined in RFC 4422.
+package sasl
+
+// Note:
+//   Most of this code was copied, with some modifications, from net/smtp. It
+//   would be better if Go provided a standard package (e.g. crypto/sasl) that
+//   could be shared by SMTP, IMAP, and other packages.
+
+import (
+	"errors"
+)
+
+// Common SASL errors.
+var (
+	ErrUnexpectedClientResponse = errors.New("sasl: unexpected client response")
+	ErrUnexpectedServerChallenge = errors.New("sasl: unexpected server challenge")
+)
+
+// Client interface to perform challenge-response authentication.
+type Client interface {
+	// Begins SASL authentication with the server. It returns the
+	// authentication mechanism name and "initial response" data (if required by
+	// the selected mechanism). A non-nil error causes the client to abort the
+	// authentication attempt.
+	//
+	// A nil ir value is different from a zero-length value. The nil value
+	// indicates that the selected mechanism does not use an initial response,
+	// while a zero-length value indicates an empty initial response, which must
+	// be sent to the server.
+	Start() (mech string, ir []byte, err error)
+
+	// Continues challenge-response authentication. A non-nil error causes
+	// the client to abort the authentication attempt.
+	Next(challenge []byte) (response []byte, err error)
+}
+
+// Server interface to perform challenge-response authentication.
+type Server interface {
+	// Begins or continues challenge-response authentication. If the client
+	// supplies an initial response, response is non-nil.
+	//
+	// If the authentication is finished, done is set to true. If the
+	// authentication has failed, an error is returned.
+	Next(response []byte) (challenge []byte, done bool, err error)
+}