Move registry package into handler package

The goal is to free up the distribution/registry package to include common
registry types. This moves the webapp definitions out of the way to allow for
this change in the future.

Signed-off-by: Stephen J Day <stephen.day@docker.com>

docs/handlers/hmac_test.go

@@ -0,0 +1,117 @@
+package handlers
+
+import "testing"
+
+var layerUploadStates = []layerUploadState{
+	{
+		Name:   "hello",
+		UUID:   "abcd-1234-qwer-0987",
+		Offset: 0,
+	},
+	{
+		Name:   "hello-world",
+		UUID:   "abcd-1234-qwer-0987",
+		Offset: 0,
+	},
+	{
+		Name:   "h3ll0_w0rld",
+		UUID:   "abcd-1234-qwer-0987",
+		Offset: 1337,
+	},
+	{
+		Name:   "ABCDEFG",
+		UUID:   "ABCD-1234-QWER-0987",
+		Offset: 1234567890,
+	},
+	{
+		Name:   "this-is-A-sort-of-Long-name-for-Testing",
+		UUID:   "dead-1234-beef-0987",
+		Offset: 8675309,
+	},
+}
+
+var secrets = []string{
+	"supersecret",
+	"12345",
+	"a",
+	"SuperSecret",
+	"Sup3r... S3cr3t!",
+	"This is a reasonably long secret key that is used for the purpose of testing.",
+	"\u2603+\u2744", // snowman+snowflake
+}
+
+// TestLayerUploadTokens constructs stateTokens from LayerUploadStates and
+// validates that the tokens can be used to reconstruct the proper upload state.
+func TestLayerUploadTokens(t *testing.T) {
+	secret := hmacKey("supersecret")
+
+	for _, testcase := range layerUploadStates {
+		token, err := secret.packUploadState(testcase)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		lus, err := secret.unpackUploadState(token)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		assertLayerUploadStateEquals(t, testcase, lus)
+	}
+}
+
+// TestHMACValidate ensures that any HMAC token providers are compatible if and
+// only if they share the same secret.
+func TestHMACValidation(t *testing.T) {
+	for _, secret := range secrets {
+		secret1 := hmacKey(secret)
+		secret2 := hmacKey(secret)
+		badSecret := hmacKey("DifferentSecret")
+
+		for _, testcase := range layerUploadStates {
+			token, err := secret1.packUploadState(testcase)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			lus, err := secret2.unpackUploadState(token)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			assertLayerUploadStateEquals(t, testcase, lus)
+
+			_, err = badSecret.unpackUploadState(token)
+			if err == nil {
+				t.Fatalf("Expected token provider to fail at retrieving state from token: %s", token)
+			}
+
+			badToken, err := badSecret.packUploadState(lus)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			_, err = secret1.unpackUploadState(badToken)
+			if err == nil {
+				t.Fatalf("Expected token provider to fail at retrieving state from token: %s", badToken)
+			}
+
+			_, err = secret2.unpackUploadState(badToken)
+			if err == nil {
+				t.Fatalf("Expected token provider to fail at retrieving state from token: %s", badToken)
+			}
+		}
+	}
+}
+
+func assertLayerUploadStateEquals(t *testing.T, expected layerUploadState, received layerUploadState) {
+	if expected.Name != received.Name {
+		t.Fatalf("Expected Name=%q, Received Name=%q", expected.Name, received.Name)
+	}
+	if expected.UUID != received.UUID {
+		t.Fatalf("Expected UUID=%q, Received UUID=%q", expected.UUID, received.UUID)
+	}
+	if expected.Offset != received.Offset {
+		t.Fatalf("Expected Offset=%d, Received Offset=%d", expected.Offset, received.Offset)
+	}
+}