From c484829272cd13a738e35412498e12f2c9a194ac Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Mon, 15 Apr 2024 07:48:59 +0200
Subject: Adding upstream version 0.19.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 src/parser/base64.cpp | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 src/parser/base64.cpp

(limited to 'src/parser/base64.cpp')

diff --git a/src/parser/base64.cpp b/src/parser/base64.cpp
new file mode 100644
index 0000000..31b8267
--- /dev/null
+++ b/src/parser/base64.cpp
@@ -0,0 +1,70 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <orcus/base64.hpp>
+
+#include <boost/archive/iterators/base64_from_binary.hpp>
+#include <boost/archive/iterators/binary_from_base64.hpp>
+#include <boost/archive/iterators/transform_width.hpp>
+
+using namespace boost::archive::iterators;
+
+namespace orcus {
+
+typedef transform_width<binary_from_base64<std::vector<char>::const_iterator>, 8, 6> to_binary;
+typedef base64_from_binary<transform_width<std::vector<uint8_t>::const_iterator, 6, 8> > to_base64;
+
+std::vector<uint8_t> decode_from_base64(std::string_view base64)
+{
+    if (base64.size() < 4)
+        // Minimum of 4 characters required.
+        return std::vector<uint8_t>{};
+
+    std::vector<char> base64_seq{base64.data(), base64.data() + base64.size()};
+
+    // Check the number of trailing '='s (up to 2).
+    std::size_t pad_size = 0;
+    auto it = base64_seq.rbegin();
+    for (; pad_size < 2; ++pad_size, ++it)
+    {
+        if (*it != '=')
+            break;
+
+        *it = 'A'; // replace it with 'A' which is a base64 encoding of '\0'.
+    }
+
+    std::vector<uint8_t> decoded{to_binary(base64_seq.begin()), to_binary(base64_seq.end())};
+    decoded.erase(decoded.end() - pad_size, decoded.end());
+
+    return decoded;
+}
+
+std::string encode_to_base64(const std::vector<uint8_t>& input)
+{
+    if (input.empty())
+        return std::string{};
+
+    std::vector<uint8_t> inp = input;
+    size_t pad_size = (3 - inp.size() % 3) % 3;
+    inp.resize(inp.size() + pad_size);
+
+    std::string encoded{to_base64(inp.begin()), to_base64(inp.end())};
+
+    auto it = encoded.rbegin();
+    for (size_t i = 0; i < pad_size; ++i, ++it)
+    {
+        // 'A' is a base64 encoding of '\0'
+        // replace them with padding charachters '='
+        if (*it == 'A')
+            *it = '=';
+    }
+
+    return encoded;
+}
+
+}
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
-- 
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