fix: use pg_saslprep library to saslprep credentials, re-enable password auth over TLS

lib/supavisor/client_authentication/validation_secrets.ex

@@ -49,7 +49,7 @@ defmodule Supavisor.ClientAuthentication.ValidationSecrets do
   defp sasl_secrets_from_password(user, password) do
     iterations = 4096
     salt = :crypto.strong_rand_bytes(16)
-    salted_password = :pgo_scram.hi(:pgo_sasl_prep_profile.validate([password]), salt, iterations)
+    salted_password = :pgo_scram.hi(PgSASLprep.scram_normalize(password), salt, iterations)
     client_key = :pgo_scram.hmac(salted_password, "Client Key")
     stored_key = :pgo_scram.h(client_key)
     server_key = :pgo_scram.hmac(salted_password, "Server Key")

lib/supavisor/client_handler/auth_methods.ex

@@ -24,9 +24,8 @@ defmodule Supavisor.ClientHandler.AuthMethods do
           {:ok, :jit | :password | :scram_sha_256} | {:error, SslRequiredError.t()}
   def fetch_authentication_method(tenant, client_jit, ssl?, user) do
     case {tenant.use_jit, client_jit, ssl?} do
-      {false, _, _} -> {:ok, :scram_sha_256}
-      {true, false, false} -> {:ok, :scram_sha_256}
-      {true, false, true} -> {:ok, :password}
+      {_, false, false} -> {:ok, :scram_sha_256}
+      {_, false, true} -> {:ok, :password}
       {true, true, false} -> {:error, %SslRequiredError{user: user}}
       {true, true, true} -> {:ok, :jit}
     end

lib/supavisor/client_handler/auth_methods/password.ex

@@ -88,7 +88,7 @@ defmodule Supavisor.ClientHandler.AuthMethods.Password do
       else
         salted_password =
           :pgo_scram.hi(
-            :pgo_sasl_prep_profile.validate([password]),
+            PgSASLprep.scram_normalize(password),
             sasl_secrets.salt,
             sasl_secrets.iterations
           )

lib/supavisor/helpers.ex

@@ -237,7 +237,9 @@ defmodule Supavisor.Helpers do
     salt = srv_first.salt
     i = srv_first.i
 
-    salted_password = :pgo_scram.hi(:pgo_sasl_prep_profile.validate(secrets.password), salt, i)
+    salted_password =
+      :pgo_scram.hi(PgSASLprep.scram_normalize(IO.iodata_to_binary(secrets.password)), salt, i)
+
     client_key = :pgo_scram.hmac(salted_password, "Client Key")
     stored_key = :pgo_scram.h(client_key)
     client_first_bare = [<<"n=">>, user_name, <<",r=">>, client_nonce]
@@ -291,7 +293,11 @@ defmodule Supavisor.Helpers do
         %Supavisor.Secrets.SASLSecrets{} = secrets
       ) do
     salted_password =
-      :pgo_scram.hi(:pgo_sasl_prep_profile.validate(password), secrets.salt, secrets.iterations)
+      :pgo_scram.hi(
+        PgSASLprep.scram_normalize(IO.iodata_to_binary(password)),
+        secrets.salt,
+        secrets.iterations
+      )
 
     client_key = :pgo_scram.hmac(salted_password, "Client Key")
     stored_key = :pgo_scram.h(client_key)

mix.exs

@@ -75,6 +75,8 @@ defmodule Supavisor.MixProject do
       {:poolboy, git: "https://github.com/supabase/poolboy", tag: "v0.0.3"},
       {:syn, "~> 3.3"},
       {:pgo, "~> 0.13"},
+      {:pg_saslprep,
+       github: "v0idpwn/pg_saslprep", ref: "455e2e50757e8e5e091c00be4c1b9818612e3ca2"},
       {:rustler, "~> 0.36.1"},
       {:ranch, "~> 2.0", override: true},
 

mix.lock

@@ -46,6 +46,7 @@
   "open_api_spex": {:hex, :open_api_spex, "3.21.2", "6a704f3777761feeb5657340250d6d7332c545755116ca98f33d4b875777e1e5", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:plug, "~> 1.7", [hex: :plug, repo: "hexpm", optional: false]}, {:poison, "~> 3.0 or ~> 4.0 or ~> 5.0 or ~> 6.0", [hex: :poison, repo: "hexpm", optional: true]}, {:ymlr, "~> 2.0 or ~> 3.0 or ~> 4.0 or ~> 5.0", [hex: :ymlr, repo: "hexpm", optional: true]}], "hexpm", "f42ae6ed668b895ebba3e02773cfb4b41050df26f803f2ef634c72a7687dc387"},
   "opentelemetry_api": {:hex, :opentelemetry_api, "1.4.0", "63ca1742f92f00059298f478048dfb826f4b20d49534493d6919a0db39b6db04", [:mix, :rebar3], [], "hexpm", "3dfbbfaa2c2ed3121c5c483162836c4f9027def469c41578af5ef32589fcfc58"},
   "peep": {:hex, :peep, "4.4.0", "4b6289e7258ecf2741041068932455eb8389673bca785623621ddb6935286845", [:mix], [{:nimble_options, "~> 1.1", [hex: :nimble_options, repo: "hexpm", optional: false]}, {:plug, "~> 1.16", [hex: :plug, repo: "hexpm", optional: true]}, {:telemetry, "~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}, {:telemetry_metrics, "~> 1.0", [hex: :telemetry_metrics, repo: "hexpm", optional: false]}], "hexpm", "f289959a9e5fcf92f5a4becaf4dd0df95c58841368f6ad0574b8ea830a7c1453"},
+  "pg_saslprep": {:git, "https://github.com/v0idpwn/pg_saslprep.git", "455e2e50757e8e5e091c00be4c1b9818612e3ca2", [ref: "455e2e50757e8e5e091c00be4c1b9818612e3ca2"]},
   "pg_types": {:hex, :pg_types, "0.4.0", "3ce365c92903c5bb59c0d56382d842c8c610c1b6f165e20c4b652c96fa7e9c14", [:rebar3], [], "hexpm", "b02efa785caececf9702c681c80a9ca12a39f9161a846ce17b01fb20aeeed7eb"},
   "pgo": {:hex, :pgo, "0.14.0", "f53711d103d7565db6fc6061fcf4ff1007ab39892439be1bb02d9f686d7e6663", [:rebar3], [{:backoff, "~> 1.1.6", [hex: :backoff, repo: "hexpm", optional: false]}, {:opentelemetry_api, "~> 1.0", [hex: :opentelemetry_api, repo: "hexpm", optional: false]}, {:pg_types, "~> 0.4.0", [hex: :pg_types, repo: "hexpm", optional: false]}], "hexpm", "71016c22599936e042dc0012ee4589d24c71427d266292f775ebf201d97df9c9"},
   "phoenix": {:hex, :phoenix, "1.7.23", "2a86f055b50f3ca2e692f8bc0e757b7bde6a44182476ec9193e337ccb7cf5492", [:mix], [{:castore, ">= 0.0.0", [hex: :castore, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 2.1", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:phoenix_template, "~> 1.0", [hex: :phoenix_template, repo: "hexpm", optional: false]}, {:phoenix_view, "~> 2.0", [hex: :phoenix_view, repo: "hexpm", optional: true]}, {:plug, "~> 1.14", [hex: :plug, repo: "hexpm", optional: false]}, {:plug_cowboy, "~> 2.7", [hex: :plug_cowboy, repo: "hexpm", optional: true]}, {:plug_crypto, "~> 1.2 or ~> 2.0", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}, {:websock_adapter, "~> 0.5.3", [hex: :websock_adapter, repo: "hexpm", optional: false]}], "hexpm", "98b551a267cbcd0ca4a2bfe05ff2fb3cd68699197a2a3e14504f6b7be758ca9d"},

test/integration/protocol_integration_test.exs

@@ -215,14 +215,148 @@
     # end
   end
 
-  defp recv_until_ready_for_query(sock, buf) do
-    {pkts, ""} = Supavisor.Protocol.split_pkts(buf)
+  describe "fullwidth password (SASLprep private-use bug workaround)" do
+    # `:pgo_sasl_prep_profile.validate/1` has a buggy private-use range that
+    # incorrectly rejects characters in the BMP (e.g. fullwidth `！` U+FF01).
+    @password String.duplicate("！", 8)
+    @role "fullwidth_pw_user"
+    @tenant "is_manager"
+
+    setup do
+      Supavisor.Support.SSLHelper.setup_downstream_certs()
+
+      db_conf = Application.get_env(:supavisor, Supavisor.Repo)
+
+      {:ok, origin} = connect_origin(db_conf)
+      Postgrex.query!(origin, "DROP ROLE IF EXISTS #{@role};", [])
+
+      Postgrex.query!(
+        origin,
+        "CREATE ROLE #{@role} WITH LOGIN PASSWORD '#{@password}';",
+        []
+      )
+
+      on_exit(fn ->
+        {:ok, cleanup} = connect_origin(db_conf)
+        Postgrex.query!(cleanup, "DROP ROLE IF EXISTS #{@role};", [])
+      end)
+
+      %{
+        db_conf: db_conf,
+        port: Application.get_env(:supavisor, :proxy_port_transaction),
+        username: "#{@role}.#{@tenant}"
+      }
+    end
+
+    test "authenticates over plain TCP (SCRAM)", ctx do
+      {:ok, sock} = :gen_tcp.connect(~c"127.0.0.1", ctx.port, [:binary, active: false])
+
+      send_startup(:gen_tcp, sock, ctx)
+      auth_tail = do_scram_exchange(:gen_tcp, sock, ctx.username, @password)
+      recv_until_ready_for_query(:gen_tcp, sock, auth_tail)
+
+      :ok = :gen_tcp.send(sock, :pgo_protocol.encode_query_message("SELECT 1"))
+      {:ok, data} = :gen_tcp.recv(sock, 0, 5000)
+      assert_data_row(data)
+      :gen_tcp.close(sock)
+    end
+
+    test "authenticates over SSL (cleartext password)", ctx do
+      {:ok, tcp} = :gen_tcp.connect(~c"127.0.0.1", ctx.port, [:binary, active: false])
+      :ok = :gen_tcp.send(tcp, Server.ssl_request_message())
+      {:ok, "S"} = :gen_tcp.recv(tcp, 1, 5000)
+      {:ok, ssl} = :ssl.connect(tcp, [verify: :verify_none, active: false], 5000)
+
+      send_startup(:ssl, ssl, ctx)
+
+      {:ok, <<?R, _::32, 3::32>>} = :ssl.recv(ssl, 0, 5000)
+
+      pw = @password <> <<0>>
+      :ok = :ssl.send(ssl, [<<?p, byte_size(pw) + 4::32>>, pw])
+
+      recv_until_ready_for_query(:ssl, ssl, "")
+
+      :ok = :ssl.send(ssl, :pgo_protocol.encode_query_message("SELECT 1"))
+      {:ok, data} = :ssl.recv(ssl, 0, 5000)
+      assert_data_row(data)
+      :ssl.close(ssl)
+    end
+
+    defp connect_origin(db_conf) do
+      Postgrex.start_link(
+        hostname: db_conf[:hostname],
+        port: db_conf[:port],
+        database: db_conf[:database],
+        password: db_conf[:password],
+        username: db_conf[:username]
+      )
+    end
+
+    defp send_startup(transport, sock, ctx) do
+      startup =
+        :pgo_protocol.encode_startup_message([
+          {"user", ctx.username},
+          {"database", to_string(ctx.db_conf[:database])}
+        ])
+
+      :ok = transport.send(sock, startup)
+    end
+
+    # Mirrors `:pgo_scram.get_client_final/4` but routes the password through
+    # `PgSASLprep` instead of the buggy `:pgo_sasl_prep_profile.validate/1`.
+    defp do_scram_exchange(transport, sock, user, password) do
+      {:ok, <<?R, _::32, 10::32, methods_bin::binary>>} = transport.recv(sock, 0, 5000)
+      assert "SCRAM-SHA-256" in :pgo_protocol.decode_strings(methods_bin)
+
+      nonce = :pgo_scram.get_nonce(16)
+      client_first = :pgo_scram.get_client_first(user, nonce)
+      client_first_size = :erlang.iolist_size(client_first)
+      sasl_initial = ["SCRAM-SHA-256", 0, <<client_first_size::32>>, client_first]
+      :ok = transport.send(sock, :pgo_protocol.encode_scram_response_message(sasl_initial))
+
+      {:ok, <<?R, _::32, 11::32, server_first::binary>>} = transport.recv(sock, 0, 5000)
+      sf = :pgo_scram.parse_server_first(server_first, nonce)
+      salt = :proplists.get_value(:salt, sf)
+      i = :proplists.get_value(:i, sf)
+      server_first_raw = :proplists.get_value(:raw, sf)
+      server_nonce = :proplists.get_value(:nonce, sf)
+
+      salted_password = :pgo_scram.hi(PgSASLprep.scram_normalize(password), salt, i)
+      client_key = :pgo_scram.hmac(salted_password, "Client Key")
+      stored_key = :pgo_scram.h(client_key)
+      client_first_bare = ["n=", user, ",r=", nonce]
+      client_final_no_proof = ["c=biws,r=", server_nonce]
+      auth_message = [client_first_bare, ",", server_first_raw, ",", client_final_no_proof]
+      client_signature = :pgo_scram.hmac(stored_key, auth_message)
+      client_proof = :pgo_scram.bin_xor(client_key, client_signature)
+      server_key = :pgo_scram.hmac(salted_password, "Server Key")
+      server_proof = :pgo_scram.hmac(server_key, auth_message)
+
+      client_final = [client_final_no_proof, ",p=", Base.encode64(client_proof)]
+      :ok = transport.send(sock, :pgo_protocol.encode_scram_response_message(client_final))
+
+      {:ok, auth_data} = transport.recv(sock, 0, 5000)
+      {pkts, rest} = Supavisor.Protocol.split_pkts(auth_data)
+      assert rest == ""
+      [<<?R, _::32, 12::32, server_final::binary>> | tail] = pkts
+      {:ok, ^server_proof} = :pgo_scram.parse_server_final(server_final)
+      IO.iodata_to_binary(tail)
+    end
+
+    defp assert_data_row(data) do
+      {pkts, _} = Supavisor.Protocol.split_pkts(data)
+      assert Enum.any?(pkts, &match?(<<?D, _::binary>>, &1))
+    end
+  end
+
+  defp recv_until_ready_for_query(transport \\ :gen_tcp, sock, buf) do
+    {pkts, rest} = Supavisor.Protocol.split_pkts(buf)
 
     if Enum.any?(pkts, &match?(<<?Z, _::binary>>, &1)) do
       :ok
     else
-      {:ok, more} = :gen_tcp.recv(sock, 0, 5000)
-      recv_until_ready_for_query(sock, more)
+      {:ok, more} = transport.recv(sock, 0, 5000)
+      recv_until_ready_for_query(transport, sock, rest <> more)
     end
   end
 end