From 49fa5aa2a127bdf8924d02bf77e5086b39c7a447 Mon Sep 17 00:00:00 2001
From: Calvin Morrison <calvin@pobox.com>
Date: Wed, 3 Sep 2025 21:15:36 -0400
Subject: i vibe coded it

---
 .../_build/default/lib/base64url/src/base64url.erl | 98 ++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 server/_build/default/lib/base64url/src/base64url.erl

(limited to 'server/_build/default/lib/base64url/src/base64url.erl')

diff --git a/server/_build/default/lib/base64url/src/base64url.erl b/server/_build/default/lib/base64url/src/base64url.erl
new file mode 100644
index 0000000..fa38269
--- /dev/null
+++ b/server/_build/default/lib/base64url/src/base64url.erl
@@ -0,0 +1,98 @@
+%%
+%% @doc URL safe base64-compatible codec.
+%%
+%% Based heavily on the code extracted from:
+%%   https://github.com/basho/riak_control/blob/master/src/base64url.erl and
+%%   https://github.com/mochi/mochiweb/blob/master/src/mochiweb_base64url.erl.
+%%
+
+-module(base64url).
+-author('Vladimir Dronnikov <dronnikov@gmail.com>').
+
+-export([
+    decode/1,
+    encode/1,
+    encode_mime/1
+  ]).
+
+-spec encode(
+    binary() | iolist()
+  ) -> binary().
+
+encode(Bin) when is_binary(Bin) ->
+  << << (urlencode_digit(D)) >> || <<D>> <= base64:encode(Bin), D =/= $= >>;
+encode(L) when is_list(L) ->
+  encode(iolist_to_binary(L)).
+
+-spec encode_mime(
+    binary() | iolist()
+  ) -> binary().
+encode_mime(Bin) when is_binary(Bin) ->
+    << << (urlencode_digit(D)) >> || <<D>> <= base64:encode(Bin) >>;
+encode_mime(L) when is_list(L) ->
+    encode_mime(iolist_to_binary(L)).
+
+-spec decode(
+    binary() | iolist()
+  ) -> binary().
+
+decode(Bin) when is_binary(Bin) ->
+  Bin2 = case byte_size(Bin) rem 4 of
+    % 1 -> << Bin/binary, "===" >>;
+    2 -> << Bin/binary, "==" >>;
+    3 -> << Bin/binary, "=" >>;
+    _ -> Bin
+  end,
+  base64:decode(<< << (urldecode_digit(D)) >> || <<D>> <= Bin2 >>);
+decode(L) when is_list(L) ->
+  decode(iolist_to_binary(L)).
+
+urlencode_digit($/) -> $_;
+urlencode_digit($+) -> $-;
+urlencode_digit(D)  -> D.
+
+urldecode_digit($_) -> $/;
+urldecode_digit($-) -> $+;
+urldecode_digit(D)  -> D.
+
+-ifdef(TEST).
+-include_lib("eunit/include/eunit.hrl").
+
+aim_test() ->
+  % vanilla base64 produce URL unsafe output
+  ?assertNotEqual(
+      binary:match(base64:encode([255,127,254,252]), [<<"=">>, <<"/">>, <<"+">>]),
+      nomatch),
+  % this codec produce URL safe output
+  ?assertEqual(
+      binary:match(encode([255,127,254,252]), [<<"=">>, <<"/">>, <<"+">>]),
+      nomatch),
+  % the mime codec produces URL unsafe output, but only because of padding
+  ?assertEqual(
+      binary:match(encode_mime([255,127,254,252]), [<<"/">>, <<"+">>]),
+      nomatch),
+  ?assertNotEqual(
+      binary:match(encode_mime([255,127,254,252]), [<<"=">>]),
+      nomatch).
+
+codec_test() ->
+  % codec is lossless with or without padding
+  ?assertEqual(decode(encode(<<"foo">>)), <<"foo">>),
+  ?assertEqual(decode(encode(<<"foo1">>)), <<"foo1">>),
+  ?assertEqual(decode(encode(<<"foo12">>)), <<"foo12">>),
+  ?assertEqual(decode(encode(<<"foo123">>)), <<"foo123">>),
+  ?assertEqual(decode(encode_mime(<<"foo">>)), <<"foo">>),
+  ?assertEqual(decode(encode_mime(<<"foo1">>)), <<"foo1">>),
+  ?assertEqual(decode(encode_mime(<<"foo12">>)), <<"foo12">>),
+  ?assertEqual(decode(encode_mime(<<"foo123">>)), <<"foo123">>).
+
+iolist_test() ->
+  % codec supports iolists
+  ?assertEqual(decode(encode("foo")), <<"foo">>),
+  ?assertEqual(decode(encode(["fo", "o1"])), <<"foo1">>),
+  ?assertEqual(decode(encode([255,127,254,252])), <<255,127,254,252>>),
+  ?assertEqual(decode(encode_mime("foo")), <<"foo">>),
+  ?assertEqual(decode(encode_mime(["fo", "o1"])), <<"foo1">>),
+  ?assertEqual(decode(encode_mime([255,127,254,252])), <<255,127,254,252>>).
+
+-endif.
-- 
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