diff --git a/helper/config/validator.go b/helper/config/validator.go
new file mode 100644
index 000000000..095a0bbcb
--- /dev/null
+++ b/helper/config/validator.go
@@ -0,0 +1,48 @@
+package config
+
+import (
+	"fmt"
+
+	"github.com/hashicorp/terraform/terraform"
+)
+
+// Validator is a helper that helps you validate the configuration
+// of your resource, resource provider, etc.
+type Validator struct {
+	Required []string
+	Optional []string
+}
+
+func (v *Validator) Validate(
+	c *terraform.ResourceConfig) (ws []string, es []error) {
+	keySet := make(map[string]bool)
+	reqSet := make(map[string]struct{})
+	for _, k := range v.Required {
+		keySet[k] = true
+		reqSet[k] = struct{}{}
+	}
+	for _, k := range v.Optional {
+		keySet[k] = false
+	}
+
+	// Find any unknown keys used and mark off required keys that
+	// we have set.
+	for k, _ := range c.Raw {
+		_, ok := keySet[k]
+		if !ok {
+			es = append(es, fmt.Errorf(
+				"Unknown configuration key: %s", k))
+			continue
+		}
+
+		delete(reqSet, k)
+	}
+
+	// Check what keys are required that we didn't set
+	for k, _ := range reqSet {
+		es = append(es, fmt.Errorf(
+			"Required key is not set: %s", k))
+	}
+
+	return
+}
diff --git a/helper/config/validator_test.go b/helper/config/validator_test.go
new file mode 100644
index 000000000..8a42e8d2e
--- /dev/null
+++ b/helper/config/validator_test.go
@@ -0,0 +1,67 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform/config"
+	"github.com/hashicorp/terraform/terraform"
+)
+
+func TestValidator(t *testing.T) {
+	v := &Validator{
+		Required: []string{"foo"},
+		Optional: []string{"bar"},
+	}
+
+	var c *terraform.ResourceConfig
+
+	// Valid
+	c = testConfig(t, map[string]interface{}{
+		"foo": "bar",
+	})
+	testValid(t, v, c)
+
+	// Missing required
+	c = testConfig(t, map[string]interface{}{
+		"bar": "baz",
+	})
+	testInvalid(t, v, c)
+
+	// Unknown key
+	c = testConfig(t, map[string]interface{}{
+		"foo":  "bar",
+		"what": "what",
+	})
+	testInvalid(t, v, c)
+}
+
+func testConfig(
+	t *testing.T,
+	c map[string]interface{}) *terraform.ResourceConfig {
+	r, err := config.NewRawConfig(c)
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	return terraform.NewResourceConfig(r)
+}
+
+func testInvalid(t *testing.T, v *Validator, c *terraform.ResourceConfig) {
+	ws, es := v.Validate(c)
+	if len(ws) > 0 {
+		t.Fatalf("bad: %#v", ws)
+	}
+	if len(es) == 0 {
+		t.Fatalf("bad: %#v", es)
+	}
+}
+
+func testValid(t *testing.T, v *Validator, c *terraform.ResourceConfig) {
+	ws, es := v.Validate(c)
+	if len(ws) > 0 {
+		t.Fatalf("bad: %#v", ws)
+	}
+	if len(es) > 0 {
+		t.Fatalf("bad: %#v", es)
+	}
+}