add server-side plugins registry

auth/plugins/plugins.go

@@ -0,0 +1,11 @@
+package plugins
+
+import (
+	"github.com/francoismichel/ssh3/server_auth"
+	"github.com/francoismichel/ssh3/internal"
+)
+
+// Registers a new server-side auth plugin
+func RegisterServerIdentity(name string, identity server_auth.Identity) error {
+	return internal.RegisterServerIdentity(name, identity)
+}

cmd/plugin_endpoint/main.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	cmd "github.com/francoismichel/ssh3/cmd"
+)
+
+func main() {
+	cmd.ClientMain()
+}

cmd/ssh3-server.go

@@ -28,6 +28,7 @@ import (
 	"go.uber.org/zap/zapcore"
 
 	ssh3 "github.com/francoismichel/ssh3"
+	"github.com/francoismichel/ssh3/internal"
 	ssh3Messages "github.com/francoismichel/ssh3/message"
 	"github.com/francoismichel/ssh3/server_auth"
 	util "github.com/francoismichel/ssh3/util"
@@ -708,6 +709,8 @@ func ServerMain() int {
 		return 0
 	}
 
+	internal.CloseRegistry()
+
 	if !enablePasswordLogin {
 		fmt.Fprintln(os.Stderr, "password login is disabled")
 	}

cmd/ssh3.go

@@ -24,6 +24,7 @@ import (
 	"github.com/francoismichel/ssh3"
 	"github.com/francoismichel/ssh3/auth"
 	"github.com/francoismichel/ssh3/client"
+	"github.com/francoismichel/ssh3/internal"
 	"github.com/francoismichel/ssh3/util"
 	"github.com/quic-go/quic-go"
 	"github.com/quic-go/quic-go/http3"
@@ -330,6 +331,8 @@ func ClientMain() int {
 	flag.Parse()
 	args := flag.Args()
 
+	internal.CloseRegistry()
+
 	if *displayVersion {
 		fmt.Fprintln(os.Stdout, filepath.Base(os.Args[0]), "version", ssh3.GetCurrentSoftwareVersion())
 		return 0

internal/plugins.go

@@ -0,0 +1,43 @@
+package internal
+
+import (
+	"sync"
+
+	"github.com/francoismichel/ssh3/server_auth"
+	. "github.com/francoismichel/ssh3/util"
+)
+
+type serverPluginsRegistry struct {
+	registrationsOpen 	   bool
+	serverPluginIdentities map[string]server_auth.Identity
+}
+
+var (
+	serverPluginsMutex sync.RWMutex
+	serverRegistry = &serverPluginsRegistry{ registrationsOpen: true, serverPluginIdentities: make(map[string]server_auth.Identity) }
+)
+
+// Registers a new server-side auth plugin
+func RegisterServerIdentity(name string, identity server_auth.Identity) error {
+	serverPluginsMutex.Lock()
+	defer serverPluginsMutex.Unlock()
+	if !serverRegistry.registrationsOpen {
+		return ClosedPluginsRegistry{}
+	}
+	if identity == nil {
+		panic("plugin registry is nil")
+	}
+	if _, dup := serverRegistry.serverPluginIdentities[name]; dup {
+		panic("RegisterServerIdentity called twice for same auth plugin name " + name)
+	}
+	serverRegistry.serverPluginIdentities[name] = identity
+	return nil
+}
+
+// Closes the registry. This function should not be exported outside the scope of the module
+// to avoid plugins closing the registry.
+func CloseRegistry() {
+	serverPluginsMutex.Lock()
+	defer serverPluginsMutex.Unlock()
+	serverRegistry.registrationsOpen = false
+}

util/types.go

@@ -78,6 +78,14 @@ func (e InvalidConfig) Error() string {
 	return fmt.Sprintf("Invalid %s config field: \"%s\"", e.Field, e.Value)
 }
 
+type ClosedPluginsRegistry struct {
+
+}
+
+func (e ClosedPluginsRegistry) Error() string {
+	return "The plugins registry is closed"
+}
+
 type BytesReadCloser struct {
 	*bytes.Reader
 }