From a1e7ed99249b9bd92adce015b50db931a7db3502 Mon Sep 17 00:00:00 2001
From: Dylan G <1565516+Helloman892@users.noreply.github.com>
Date: Mon, 30 May 2022 12:03:11 +0100
Subject: [PATCH] Added header-only URL encoding/decoding

---
 include/urls.h | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 include/urls.h

diff --git a/include/urls.h b/include/urls.h
new file mode 100644
index 0000000..c6093c6
--- /dev/null
+++ b/include/urls.h
@@ -0,0 +1,88 @@
+/*
+*   This file is part of Anemone3DS
+*   Copyright (C) 2016-2020 Contributors in CONTRIBUTORS.md
+*
+*   This program is free software: you can redistribute it and/or modify
+*   it under the terms of the GNU General Public License as published by
+*   the Free Software Foundation, either version 3 of the License, or
+*   (at your option) any later version.
+*
+*   This program is distributed in the hope that it will be useful,
+*   but WITHOUT ANY WARRANTY; without even the implied warranty of
+*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*   GNU General Public License for more details.
+*
+*   You should have received a copy of the GNU General Public License
+*   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*
+*   Additional Terms 7.b and 7.c of GPLv3 apply to this file:
+*       * Requiring preservation of specified reasonable legal notices or
+*         author attributions in that material or in the Appropriate Legal
+*         Notices displayed by works containing it.
+*       * Prohibiting misrepresentation of the origin of that material,
+*         or requiring that modified versions of such material be marked in
+*         reasonable ways as different from the original version.
+*/
+
+static char from_hex(char c)
+{
+    return isdigit(c) ? c - '0' : tolower(c) - 'a' + 10;
+}
+
+static char to_hex(char code)
+{
+    static char hex[] = "0123456789abcdef";
+    return hex[code & 15];
+}
+
+// ensure caller frees
+char * url_escape(char * url)
+{
+    char * ptr = url;
+    char * buf = malloc(3 * strlen(url) + 1);
+    char * ptr_buf = buf;
+
+    while (*ptr)
+    {
+        if (isalnum((int)*ptr) || strchr("-_.~", *ptr))
+            *ptr_buf++ = *ptr;
+        else if (*ptr == ' ')
+            *ptr_buf++ = '+';
+        else
+        {
+            *ptr_buf++ = '%';
+            *ptr_buf++ = to_hex(*ptr >> 4);
+            *ptr_buf++ = to_hex(*ptr & 15);
+        }
+        ptr++;
+    }
+    *ptr_buf = '\0';
+    return buf;
+}
+
+// ensure caller frees
+char * url_unescape(char * url)
+{
+    char * ptr = url;
+    char * buf = malloc(strlen(url) + 1);
+    char * ptr_buf = buf;
+
+    while (*ptr)
+    {
+        if (*ptr == '%')
+        {
+            if (ptr[1] && ptr[2])
+            {
+                *ptr_buf++ = from_hex(ptr[1]) << 4 | from_hex(ptr[2]);
+                ptr += 2;
+            }
+        }
+        else if (*ptr == '+')
+            *ptr_buf++ = ' ';
+        else
+            *ptr_buf++ = *ptr;
+        ptr++;
+    }
+    *ptr_buf = '\0';
+    return buf;
+}