1 files changed, 46 insertions, 0 deletions
diff --git a/lib/pleroma/keys.ex b/lib/pleroma/keys.ex
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+++ b/lib/pleroma/keys.ex
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+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Keys do
+  # Native generation of RSA keys is only available since OTP 20+ and in default build conditions
+  # We try at compile time to generate natively an RSA key otherwise we fallback on the old way.
+  try do
+    _ = :public_key.generate_key({:rsa, 2048, 65_537})
+
+    def generate_rsa_pem do
+      key = :public_key.generate_key({:rsa, 2048, 65_537})
+      entry = :public_key.pem_entry_encode(:RSAPrivateKey, key)
+      pem = :public_key.pem_encode([entry]) |> String.trim_trailing()
+      {:ok, pem}
+    end
+  rescue
+    _ ->
+      def generate_rsa_pem do
+        port = Port.open({:spawn, "openssl genrsa"}, [:binary])
+
+        {:ok, pem} =
+          receive do
+            {^port, {:data, pem}} -> {:ok, pem}
+          end
+
+        Port.close(port)
+
+        if Regex.match?(~r/RSA PRIVATE KEY/, pem) do
+          {:ok, pem}
+        else
+          :error
+        end
+      end
+  end
+
+  def keys_from_pem(pem) do
+    with [private_key_code] <- :public_key.pem_decode(pem),
+         private_key <- :public_key.pem_entry_decode(private_key_code),
+         {:RSAPrivateKey, _, modulus, exponent, _, _, _, _, _, _, _} <- private_key do
+      {:ok, private_key, {:RSAPublicKey, modulus, exponent}}
+    else
+      error -> {:error, error}
+    end
+  end
+end