code: func Sum(ctx context.Context, c *cli.Context, store storer) error {
  	name := c.Args().First()
  	if name == "" {
  		return action.ExitError(ctx, action.ExitUsage, nil, "Usage: %s sha256 name", c.App.Name)
  	}
  
  	if !strings.HasSuffix(name, Suffix) {
  		name += Suffix
  	}
  
  	buf, err := binaryGet(ctx, name, store)
  	if err != nil {
  		return action.ExitError(ctx, action.ExitDecrypt, err, "failed to read secret: %s", err)
  	}
  
  	h := sha256.New()
  	_, _ = h.Write(buf)
  	out.Yellow(ctx, "%x", h.Sum(nil))
  
  	return nil
  }
docs: // Sum decodes binary content and computes the SHA256 checksum