2 files changed, 57 insertions, 0 deletions
diff --git a/lib/pleroma/web/rich_media/parser/ttl.ex b/lib/pleroma/web/rich_media/parser/ttl.ex
new file mode 100644
index 000000000..0b7f14fb2
--- /dev/null
+++ b/lib/pleroma/web/rich_media/parser/ttl.ex
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+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.RichMedia.Parser.TTL do
+  @callback ttl(Map.t(), String.t()) :: Integer.t() | nil
+end
diff --git a/lib/pleroma/web/rich_media/parser/ttl/aws_signed_url.ex b/lib/pleroma/web/rich_media/parser/ttl/aws_signed_url.ex
new file mode 100644
index 000000000..c7eb267f3
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+++ b/lib/pleroma/web/rich_media/parser/ttl/aws_signed_url.ex
@@ -0,0 +1,50 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.RichMedia.Parser.TTL.AwsSignedUrl do
+  @behaviour Pleroma.Web.RichMedia.Parser.TTL
+
+  @impl true
+  def ttl(data, _url) do
+    image = Map.get(data, :image)
+
+    if is_aws_signed_url(image) do
+      image
+      |> parse_query_params()
+      |> format_query_params()
+      |> get_expiration_timestamp()
+    else
+      {:error, "Not aws signed url #{inspect(image)}"}
+    end
+  end
+
+  defp is_aws_signed_url(image) when is_binary(image) and image != "" do
+    %URI{host: host, query: query} = URI.parse(image)
+
+    String.contains?(host, "amazonaws.com") and String.contains?(query, "X-Amz-Expires")
+  end
+
+  defp is_aws_signed_url(_), do: nil
+
+  defp parse_query_params(image) do
+    %URI{query: query} = URI.parse(image)
+    query
+  end
+
+  defp format_query_params(query) do
+    query
+    |> String.split(~r/&|=/)
+    |> Enum.chunk_every(2)
+    |> Map.new(fn [k, v] -> {k, v} end)
+  end
+
+  defp get_expiration_timestamp(params) when is_map(params) do
+    {:ok, date} =
+      params
+      |> Map.get("X-Amz-Date")
+      |> Timex.parse("{ISO:Basic:Z}")
+
+    {:ok, Timex.to_unix(date) + String.to_integer(Map.get(params, "X-Amz-Expires"))}
+  end
+end