4.1

1 files changed, 159 insertions, 0 deletions

diff --git a/zen/base64.h b/zen/base64.h
new file mode 100644
index 00000000..4a81787c
--- /dev/null
+++ b/zen/base64.h
@@ -0,0 +1,159 @@
+// **************************************************************************
+// * This file is part of the zenXML project. It is distributed under the   *
+// * Boost Software License, Version 1.0. See accompanying file             *
+// * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.       *
+// * Copyright (C) 2011 ZenJu (zhnmju123 AT gmx.de)                         *
+// **************************************************************************
+#ifndef BASE64_HEADER_08473021856321840873021487213453214
+#define BASE64_HEADER_08473021856321840873021487213453214
+
+#include <iterator>
+#include <cassert>
+#include "assert_static.h"
+
+namespace zen
+{
+//http://en.wikipedia.org/wiki/Base64
+/*
+Usage:
+	const std::string input  = "Sample text";
+	std::string output;
+	zen::encodeBase64(input.begin(), input.end(), std::back_inserter(output));
+	//output contains "U2FtcGxlIHRleHQ="
+*/
+template <class InputIterator, class OutputIterator>
+OutputIterator encodeBase64(InputIterator first, InputIterator last, OutputIterator result); //throw ()
+
+template <class InputIterator, class OutputIterator>
+OutputIterator decodeBase64(InputIterator first, InputIterator last, OutputIterator result); //throw ()
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+//---------------------------------------- implementation ----------------------------------------
+namespace implementation
+{
+const char ENCODING_MIME[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; //64 chars for base64 encoding + padding char
+const signed char DECODING_MIME[] =
+{
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
+    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, 64, -1, -1,
+    -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
+    -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1
+};
+const size_t INDEX_PAD = 64;
+}
+
+
+//http://en.wikipedia.org/wiki/Base64
+template <class InputIterator, class OutputIterator> inline
+OutputIterator encodeBase64(InputIterator first, InputIterator last, OutputIterator result)
+{
+    using namespace implementation;
+    assert_static(sizeof(std::iterator_traits<InputIterator>::value_type) == 1);
+    assert_static(sizeof(ENCODING_MIME) == 65 + 1);
+
+    while (first != last)
+    {
+        const unsigned char a = *first++;
+        *result++ = ENCODING_MIME[a >> 2];
+
+        if (first == last)
+        {
+            *result++ = ENCODING_MIME[((a & 0x3) << 4)];
+            *result++ = ENCODING_MIME[INDEX_PAD];
+            *result++ = ENCODING_MIME[INDEX_PAD];
+            break;
+        }
+        const unsigned char b = *first++;
+        *result++ = ENCODING_MIME[((a & 0x3) << 4) | (b >> 4)];
+
+        if (first == last)
+        {
+            *result++ = ENCODING_MIME[((b & 0xf) << 2)];
+            *result++ = ENCODING_MIME[INDEX_PAD];
+            break;
+        }
+        const unsigned char c = *first++;
+        *result++ = ENCODING_MIME[((b & 0xf) << 2) | (c >> 6)];
+        *result++ = ENCODING_MIME[c & 0x3f];
+    }
+
+    return result;
+}
+
+
+template <class InputIterator, class OutputIterator> inline
+OutputIterator decodeBase64(InputIterator first, InputIterator last, OutputIterator result)
+{
+    using namespace implementation;
+    assert_static(sizeof(std::iterator_traits<InputIterator>::value_type) == 1);
+    assert_static(sizeof(DECODING_MIME) == 128);
+
+    const int INDEX_END = INDEX_PAD + 1;
+
+    auto readIndex = [&]() -> unsigned char //return index within [0, 64] or INDEX_END if end of input
+    {
+        while (true)
+        {
+            if (first == last)
+                return INDEX_END;
+
+            unsigned char ch = *first++;
+            if (ch < 128) //skip all unknown characters (including carriage return, line-break, tab)
+            {
+                const int index = implementation::DECODING_MIME[ch];
+                if (0 <= index && index <= INDEX_PAD) //respect padding
+                    return index;
+            }
+        }
+    };
+
+    while (true)
+    {
+        const unsigned char index1 = readIndex();
+        const unsigned char index2 = readIndex();
+        if (index1 >= INDEX_PAD || index2 >= INDEX_PAD)
+        {
+            assert(index1 == INDEX_END && index2 == INDEX_END);
+            break;
+        }
+        *result++ = (index1 << 2) | (index2 >> 4);
+
+        const unsigned char index3 = readIndex();
+        if (index3 >= INDEX_PAD) //padding
+        {
+            assert(index3 == INDEX_PAD);
+            break;
+        }
+        *result++ = ((index2 & 0xf) << 4) | (index3 >> 2);
+
+        const unsigned char index4 = readIndex();
+        if (index4 >= INDEX_PAD) //padding
+        {
+            assert(index4 == INDEX_PAD);
+            break;
+        }
+        *result++ = ((index3 & 0x3) << 6) | index4;
+    }
+    return result;
+}
+}
+
+#endif //BASE64_HEADER_08473021856321840873021487213453214