vendoring sources, for posterity sake

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

vendor/labix.org/v2/mgo/sasl/sasl.go

@@ -0,0 +1,135 @@
+// Package sasl is an implementation detail of the mgo package.
+//
+// This package is not meant to be used by itself.
+//
+package sasl
+
+// #cgo LDFLAGS: -lsasl2
+//
+// struct sasl_conn {};
+//
+// #include <stdlib.h>
+// #include <sasl/sasl.h>
+//
+// sasl_callback_t *mgo_sasl_callbacks(const char *username, const char *password);
+//
+import "C"
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+	"unsafe"
+)
+
+type saslStepper interface {
+	Step(serverData []byte) (clientData []byte, done bool, err error)
+	Close()
+}
+
+type saslSession struct {
+	conn *C.sasl_conn_t
+	step int
+	mech string
+
+	cstrings  []*C.char
+	callbacks *C.sasl_callback_t
+}
+
+var initError error
+var initOnce sync.Once
+
+func initSASL() {
+	rc := C.sasl_client_init(nil)
+	if rc != C.SASL_OK {
+		initError = saslError(rc, nil, "cannot initialize SASL library")
+	}
+}
+
+func New(username, password, mechanism, service, host string) (saslStepper, error) {
+	initOnce.Do(initSASL)
+	if initError != nil {
+		return nil, initError
+	}
+
+	ss := &saslSession{mech: mechanism}
+	if service == "" {
+		service = "mongodb"
+	}
+	if i := strings.Index(host, ":"); i >= 0 {
+		host = host[:i]
+	}
+	ss.callbacks = C.mgo_sasl_callbacks(ss.cstr(username), ss.cstr(password))
+	rc := C.sasl_client_new(ss.cstr(service), ss.cstr(host), nil, nil, ss.callbacks, 0, &ss.conn)
+	if rc != C.SASL_OK {
+		ss.Close()
+		return nil, saslError(rc, nil, "cannot create new SASL client")
+	}
+	return ss, nil
+}
+
+func (ss *saslSession) cstr(s string) *C.char {
+	cstr := C.CString(s)
+	ss.cstrings = append(ss.cstrings, cstr)
+	return cstr
+}
+
+func (ss *saslSession) Close() {
+	for _, cstr := range ss.cstrings {
+		C.free(unsafe.Pointer(cstr))
+	}
+	ss.cstrings = nil
+
+	if ss.callbacks != nil {
+		C.free(unsafe.Pointer(ss.callbacks))
+	}
+
+	// The documentation of SASL dispose makes it clear that this should only
+	// be done when the connection is done, not when the authentication phase
+	// is done, because an encryption layer may have been negotiated.
+	// Even then, we'll do this for now, because it's simpler and prevents
+	// keeping track of this state for every socket. If it breaks, we'll fix it.
+	C.sasl_dispose(&ss.conn)
+}
+
+func (ss *saslSession) Step(serverData []byte) (clientData []byte, done bool, err error) {
+	ss.step++
+	if ss.step > 10 {
+		return nil, false, fmt.Errorf("too many SASL steps without authentication")
+	}
+	var cclientData *C.char
+	var cclientDataLen C.uint
+	var rc C.int
+	if ss.step == 1 {
+		var mechanism *C.char // ignored - must match cred
+		rc = C.sasl_client_start(ss.conn, ss.cstr(ss.mech), nil, &cclientData, &cclientDataLen, &mechanism)
+	} else {
+		var cserverData *C.char
+		var cserverDataLen C.uint
+		if len(serverData) > 0 {
+			cserverData = (*C.char)(unsafe.Pointer(&serverData[0]))
+			cserverDataLen = C.uint(len(serverData))
+		}
+		rc = C.sasl_client_step(ss.conn, cserverData, cserverDataLen, nil, &cclientData, &cclientDataLen)
+	}
+	if cclientData != nil && cclientDataLen > 0 {
+		clientData = C.GoBytes(unsafe.Pointer(cclientData), C.int(cclientDataLen))
+	}
+	if rc == C.SASL_OK {
+		return clientData, true, nil
+	}
+	if rc == C.SASL_CONTINUE {
+		return clientData, false, nil
+	}
+	return nil, false, saslError(rc, ss.conn, "cannot establish SASL session")
+}
+
+func saslError(rc C.int, conn *C.sasl_conn_t, msg string) error {
+	var detail string
+	if conn == nil {
+		detail = C.GoString(C.sasl_errstring(rc, nil, nil))
+	} else {
+		detail = C.GoString(C.sasl_errdetail(conn))
+	}
+	return fmt.Errorf(msg + ": " + detail)
+}