Initial distributor implementation

common/api/dm/service/v1/activate_execution_normalize.go

Index: common/api/dm/service/v1/activate_execution_normalize.go
diff --git a/common/api/dm/service/v1/activate_execution_normalize.go b/common/api/dm/service/v1/activate_execution_normalize.go
new file mode 100644
index 0000000000000000000000000000000000000000..4d48fa1f705ceafd1193b1b52c8f2a49b6e2899e
--- /dev/null
+++ b/common/api/dm/service/v1/activate_execution_normalize.go
@@ -0,0 +1,24 @@
+// Copyright 2016 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package dm
+
+import "fmt"
+
+// MinimumActivationTokenLength is the minimum number of bytes in an appropriate
+// ExecutionToken.
+const MinimumActivationTokenLength = 32
+
+// Normalize returns an error iff the ActivateExecutionReq has bad form (nils,
+// insufficient activation token length, etc.
+func (a *ActivateExecutionReq) Normalize() error {
+	if err := a.Auth.Normalize(); err != nil {
+		return err
+	}
+	if len(a.ExecutionToken) < MinimumActivationTokenLength {
+		return fmt.Errorf("insufficiently long ExecutionToken: %d",
+			len(a.ExecutionToken))
+	}
+	return nil
+}