diff --git a/authz/browser.go b/auth/authcode.go
similarity index 87%
rename from authz/browser.go
rename to auth/authcode.go
index 29a9f0b0..9eed7503 100644
--- a/authz/browser.go
+++ b/auth/authcode.go
@@ -1,7 +1,9 @@
-package authz
+package auth
 
 import (
 	"context"
+	"crypto/rand"
+	"encoding/binary"
 	"fmt"
 	"log"
 	"net/http"
@@ -18,9 +20,9 @@ type BrowserAuthCodeFlow struct {
 // GetToken returns a token.
 func (f *BrowserAuthCodeFlow) GetToken(ctx context.Context) (*oauth2.Token, error) {
 	f.Config.RedirectURL = fmt.Sprintf("http://localhost:%d/", f.Port)
-	state, err := generateOAuthState()
+	state, err := generateState()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("Could not generate state parameter: %s", err)
 	}
 	log.Printf("Open http://localhost:%d for authorization", f.Port)
 	code, err := f.getCode(ctx, &f.Config, state)
@@ -34,6 +36,14 @@ func (f *BrowserAuthCodeFlow) GetToken(ctx context.Context) (*oauth2.Token, erro
 	return token, nil
 }
 
+func generateState() (string, error) {
+	var n uint64
+	if err := binary.Read(rand.Reader, binary.LittleEndian, &n); err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("%x", n), nil
+}
+
 func (f *BrowserAuthCodeFlow) getCode(ctx context.Context, config *oauth2.Config, state string) (string, error) {
 	codeCh := make(chan string)
 	errCh := make(chan error)
diff --git a/authn/authn.go b/auth/oidc.go
similarity index 94%
rename from authn/authn.go
rename to auth/oidc.go
index 91705b5a..cc622d81 100644
--- a/authn/authn.go
+++ b/auth/oidc.go
@@ -1,11 +1,10 @@
-package authn
+package auth
 
 import (
 	"context"
 	"fmt"
 
 	oidc "github.com/coreos/go-oidc"
-	"github.com/int128/kubelogin/authz"
 	"golang.org/x/oauth2"
 )
 
@@ -27,7 +26,7 @@ func GetTokenSet(ctx context.Context, issuer string, clientID string, clientSecr
 	if err != nil {
 		return nil, fmt.Errorf("Could not access OIDC issuer: %s", err)
 	}
-	flow := authz.BrowserAuthCodeFlow{
+	flow := BrowserAuthCodeFlow{
 		Port: 8000,
 		Config: oauth2.Config{
 			Endpoint:     provider.Endpoint(),
diff --git a/authz/authz.go b/authz/authz.go
deleted file mode 100644
index b9279eb9..00000000
--- a/authz/authz.go
+++ /dev/null
@@ -1,12 +0,0 @@
-package authz
-
-import (
-	"context"
-
-	"golang.org/x/oauth2"
-)
-
-// Flow represents an authorization method.
-type Flow interface {
-	GetToken(context.Context) (*oauth2.Token, error)
-}
diff --git a/authz/cli.go b/authz/cli.go
deleted file mode 100644
index 4c56dead..00000000
--- a/authz/cli.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package authz
-
-import (
-	"context"
-	"fmt"
-	"log"
-
-	"golang.org/x/oauth2"
-)
-
-// CLIAuthCodeFlow is a flow to get a token by keyboard interaction.
-type CLIAuthCodeFlow struct {
-	oauth2.Config
-}
-
-// GetToken returns a token by browser interaction.
-func (f *CLIAuthCodeFlow) GetToken(ctx context.Context) (*oauth2.Token, error) {
-	f.Config.RedirectURL = "urn:ietf:wg:oauth:2.0:oob"
-	state, err := generateOAuthState()
-	if err != nil {
-		return nil, err
-	}
-	authCodeURL := f.Config.AuthCodeURL(state)
-	log.Printf("Open %s for authorization", authCodeURL)
-	fmt.Print("Enter code: ")
-	var code string
-	if _, err := fmt.Scanln(&code); err != nil {
-		return nil, err
-	}
-	token, err := f.Config.Exchange(ctx, code)
-	if err != nil {
-		return nil, fmt.Errorf("Could not exchange oauth code: %s", err)
-	}
-	return token, nil
-}
diff --git a/authz/state.go b/authz/state.go
deleted file mode 100644
index 548f10e5..00000000
--- a/authz/state.go
+++ /dev/null
@@ -1,15 +0,0 @@
-package authz
-
-import (
-	"crypto/rand"
-	"encoding/binary"
-	"fmt"
-)
-
-func generateOAuthState() (string, error) {
-	var n uint64
-	if err := binary.Read(rand.Reader, binary.LittleEndian, &n); err != nil {
-		return "", err
-	}
-	return fmt.Sprintf("%x", n), nil
-}
diff --git a/cli/cli.go b/cli/cli.go
index e2620c35..cfe78ca8 100644
--- a/cli/cli.go
+++ b/cli/cli.go
@@ -7,7 +7,7 @@ import (
 	"log"
 	"net/http"
 
-	"github.com/int128/kubelogin/authn"
+	"github.com/int128/kubelogin/auth"
 	"github.com/int128/kubelogin/kubeconfig"
 	flags "github.com/jessevdk/go-flags"
 	homedir "github.com/mitchellh/go-homedir"
@@ -70,7 +70,7 @@ func (c *CLI) Run() error {
 	}}
 	ctx := context.Background()
 	ctx = context.WithValue(ctx, oauth2.HTTPClient, client)
-	token, err := authn.GetTokenSet(ctx, authProvider.IDPIssuerURL(), authProvider.ClientID(), authProvider.ClientSecret())
+	token, err := auth.GetTokenSet(ctx, authProvider.IDPIssuerURL(), authProvider.ClientID(), authProvider.ClientSecret())
 	if err != nil {
 		return fmt.Errorf("Authentication error: %s", err)
 	}