Implement Userpass auth

Author: Lucaber

client_opts.go

@@ -21,3 +21,16 @@ func WithAuthToken(token string) ClientOpts {
 		return nil
 	}
 }
+
+func WithUserpassAuth(username string, password string, opts ...UserpassAuthOpt) ClientOpts {
+	return func(c *Client) error {
+		userpassAuthProvider, err := NewUserpassAuth(c, username, password, opts...)
+		if err != nil {
+			return err
+		}
+
+		c.auth = userpassAuthProvider
+
+		return nil
+	}
+}

userpass_auth.go

@@ -0,0 +1,57 @@
+package vault
+
+func NewUserpassAuth(c *Client, username string, password string, opts ...UserpassAuthOpt) (AuthProvider, error) {
+	k := &UserpassAuth{
+		Client:     c,
+		mountPoint: "userpass",
+		username:   username,
+		password:   password,
+	}
+
+	for _, opt := range opts {
+		err := opt(k)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return k, nil
+}
+
+type UserpassAuth struct {
+	Client     *Client
+	mountPoint string
+	username   string
+	password   string
+}
+
+type userpassAuthConfig struct {
+	Password string `json:"password"`
+}
+
+func (k UserpassAuth) Auth() (*AuthResponse, error) {
+	conf := &userpassAuthConfig{
+		Password: k.password,
+	}
+
+	res := &AuthResponse{}
+
+	err := k.Client.Write([]string{"v1", "auth", k.mountPoint, "login", k.username}, conf, res, &RequestOptions{
+		SkipRenewal: true,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return res, nil
+}
+
+type UserpassAuthOpt func(k *UserpassAuth) error
+
+func WithUserpassMountPoint(mountPoint string) UserpassAuthOpt {
+	return func(k *UserpassAuth) error {
+		k.mountPoint = mountPoint
+
+		return nil
+	}
+}