From efcecfbceac1bf014b1ede38f4588931fef92586 Mon Sep 17 00:00:00 2001
From: Paragon Initiative Enterprises <security@paragonie.com>
Date: Wed, 14 Apr 2021 02:07:47 -0400
Subject: [PATCH] We need a more surgical polyfill

---
 autoload.php             |  5 ++++-
 lib/php72compat.php      | 42 +--------------------------------------
 lib/stream-xchacha20.php | 43 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 42 deletions(-)
 create mode 100644 lib/stream-xchacha20.php

diff --git a/autoload.php b/autoload.php
index d7c777b0..9ba42a0b 100644
--- a/autoload.php
+++ b/autoload.php
@@ -61,5 +61,8 @@ function sodiumCompatAutoloader($class)
     } else {
         assert(class_exists('ParagonIE_Sodium_Compat'));
     }
-    require_once (dirname(__FILE__) . '/lib/php72compat.php');
+    require_once(dirname(__FILE__) . '/lib/php72compat.php');
+} elseif (!function_exists('sodium_crypto_stream_xchacha20_xor')) {
+    // Older versions of {PHP, ext/sodium} will not define these
+    require_once(dirname(__FILE__) . '/lib/php72compat.php');
 }
diff --git a/lib/php72compat.php b/lib/php72compat.php
index 837a6753..10a061df 100644
--- a/lib/php72compat.php
+++ b/lib/php72compat.php
@@ -1218,47 +1218,7 @@ function sodium_crypto_stream_xor($message, $nonce, $key)
         return ParagonIE_Sodium_Compat::crypto_stream_xor($message, $nonce, $key);
     }
 }
-if (!is_callable('sodium_crypto_stream_xchacha20')) {
-    /**
-     * @see ParagonIE_Sodium_Compat::crypto_stream_xchacha20()
-     * @param int $len
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    function sodium_crypto_stream_xchacha20($len, $nonce, $key)
-    {
-        ParagonIE_Sodium_Compat::crypto_stream_xchacha20($len, $nonce, $key, true);
-    }
-}
-if (!is_callable('sodium_crypto_stream_xchacha20_keygen')) {
-    /**
-     * @see ParagonIE_Sodium_Compat::crypto_stream_xchacha20_keygen()
-     * @return string
-     * @throws Exception
-     */
-    function sodium_crypto_stream_xchacha20_keygen()
-    {
-        return ParagonIE_Sodium_Compat::crypto_stream_xchacha20_keygen();
-    }
-}
-if (!is_callable('sodium_crypto_stream_xchacha20_xor')) {
-    /**
-     * @see ParagonIE_Sodium_Compat::crypto_stream_xchacha20_xor()
-     * @param string $message
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    function sodium_crypto_stream_xchacha20_xor($message, $nonce, $key)
-    {
-        ParagonIE_Sodium_Compat::crypto_stream_xchacha20_xor($message, $nonce, $key, true);
-    }
-}
+require_once dirname(__FILE__) . '/stream-xchacha20.php';
 if (!is_callable('sodium_hex2bin')) {
     /**
      * @see ParagonIE_Sodium_Compat::hex2bin()
diff --git a/lib/stream-xchacha20.php b/lib/stream-xchacha20.php
new file mode 100644
index 00000000..82d42f2f
--- /dev/null
+++ b/lib/stream-xchacha20.php
@@ -0,0 +1,43 @@
+<?php
+
+if (!is_callable('sodium_crypto_stream_xchacha20')) {
+    /**
+     * @see ParagonIE_Sodium_Compat::crypto_stream_xchacha20()
+     * @param int $len
+     * @param string $nonce
+     * @param string $key
+     * @return string
+     * @throws SodiumException
+     * @throws TypeError
+     */
+    function sodium_crypto_stream_xchacha20($len, $nonce, $key)
+    {
+        return ParagonIE_Sodium_Compat::crypto_stream_xchacha20($len, $nonce, $key, true);
+    }
+}
+if (!is_callable('sodium_crypto_stream_xchacha20_keygen')) {
+    /**
+     * @see ParagonIE_Sodium_Compat::crypto_stream_xchacha20_keygen()
+     * @return string
+     * @throws Exception
+     */
+    function sodium_crypto_stream_xchacha20_keygen()
+    {
+        return ParagonIE_Sodium_Compat::crypto_stream_xchacha20_keygen();
+    }
+}
+if (!is_callable('sodium_crypto_stream_xchacha20_xor')) {
+    /**
+     * @see ParagonIE_Sodium_Compat::crypto_stream_xchacha20_xor()
+     * @param string $message
+     * @param string $nonce
+     * @param string $key
+     * @return string
+     * @throws SodiumException
+     * @throws TypeError
+     */
+    function sodium_crypto_stream_xchacha20_xor($message, $nonce, $key)
+    {
+        return ParagonIE_Sodium_Compat::crypto_stream_xchacha20_xor($message, $nonce, $key, true);
+    }
+}