1 files changed, 55 insertions, 0 deletions
diff --git a/lib/pleroma/password/pbkdf2.ex b/lib/pleroma/password/pbkdf2.ex
new file mode 100644
index 000000000..747bc1d1d
--- /dev/null
+++ b/lib/pleroma/password/pbkdf2.ex
@@ -0,0 +1,55 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Password.Pbkdf2 do
+  @moduledoc """
+  This module implements Pleroma.Password.Pbkdf2 passwords in terms of Plug.Crypto.
+  """
+
+  alias Plug.Crypto.KeyGenerator
+
+  def decode64(str) do
+    str
+    |> String.replace(".", "+")
+    |> Base.decode64!(padding: false)
+  end
+
+  def encode64(bin) do
+    bin
+    |> Base.encode64(padding: false)
+    |> String.replace("+", ".")
+  end
+
+  def verify_pass(password, hash) do
+    ["pbkdf2-" <> digest, iterations, salt, hash] = String.split(hash, "$", trim: true)
+
+    salt = decode64(salt)
+
+    iterations = String.to_integer(iterations)
+
+    digest = String.to_atom(digest)
+
+    binary_hash =
+      KeyGenerator.generate(password, salt, digest: digest, iterations: iterations, length: 64)
+
+    encode64(binary_hash) == hash
+  end
+
+  def hash_pwd_salt(password, opts \\ []) do
+    salt =
+      Keyword.get_lazy(opts, :salt, fn ->
+        :crypto.strong_rand_bytes(16)
+      end)
+
+    digest = Keyword.get(opts, :digest, :sha512)
+
+    iterations =
+      Keyword.get(opts, :iterations, Pleroma.Config.get([:password, :iterations], 160_000))
+
+    binary_hash =
+      KeyGenerator.generate(password, salt, digest: digest, iterations: iterations, length: 64)
+
+    "$pbkdf2-#{digest}$#{iterations}$#{encode64(salt)}$#{encode64(binary_hash)}"
+  end
+end