Base64 encoding/decoding added

include/WinStd/Base64.h

@@ -0,0 +1,186 @@
+/*
+    Copyright 1991-2016 Amebis
+    Copyright 2016 G<>ANT
+
+    This file is part of WinStd.
+
+    Setup 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.
+
+    Setup 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 Setup. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+#include "Common.h"
+
+#include <string>
+#include <vector>
+
+
+namespace winstd
+{
+    ///
+    /// \defgroup WinStdBase64 Base64 conversion
+    /// Provides Base64 conversion for WinStd classes
+    ///
+    /// @{
+
+    ///
+    /// Base64 encoding session
+    ///
+    class base64_enc
+    {
+    public:
+        base64_enc() : num(0) {};
+
+
+        ///
+        /// Encodes one block of information
+        ///
+        /// \param[out] out      Output
+        /// \param[in ] data     Data to encode
+        /// \param[in ] size     Length of `data` in bytes
+        /// \param[in ] is_last  Is this the last block of data?
+        ///
+        void encode(_Out_ std::string &out, _In_bytecount_(size) const void *data, _In_ size_t size, _In_opt_ bool is_last = true);
+
+
+        ///
+        /// Resets encoding session
+        ///
+        inline void clear()
+        {
+            num = 0;
+        }
+
+
+        ///
+        /// Returns maximum encoded size
+        ///
+        /// \param size  Number of bytes to encode
+        ///
+        /// \returns Maximum number of bytes for the encoded data of `size` length
+        ///
+        inline size_t enc_size(size_t size) const
+        {
+            return ((num + size + 2)/3)*4;
+        }
+
+
+    protected:
+        static inline void encode(_Inout_ std::string &out, _In_ const unsigned char buf[3])
+        {
+            out += lookup[                  buf[0] >> 2         ];
+            out += lookup[((buf[0] << 4) | (buf[1] >> 4)) & 0x3f];
+            out += lookup[((buf[1] << 2) | (buf[2] >> 6)) & 0x3f];
+            out += lookup[                  buf[2]        & 0x3f];
+        }
+
+
+        static inline void encode(_Inout_ std::string &out, _In_count_(size) const unsigned char buf[3], _In_ size_t size)
+        {
+            if (size > 0) {
+                out += lookup[buf[0] >> 2];
+                if (size > 1) {
+                    out += lookup[((buf[0] << 4) | (buf[1] >> 4)) & 0x3f];
+                    if (size > 2) {
+                        out += lookup[((buf[1] << 2) | (buf[2] >> 6)) & 0x3f];
+                        out += lookup[buf[2] & 0x3f];
+                    } else {
+                        out += lookup[(buf[1] << 2) & 0x3f];
+                        out += '=';
+                    }
+                } else {
+                    out += lookup[(buf[0] << 4) & 0x3f];
+                    out += "==";
+                }
+            } else
+                out += "====";
+        }
+
+
+    protected:
+        unsigned char buf[3];
+        size_t num;
+
+        static const char lookup[64];
+    };
+
+
+    ///
+    /// Base64 decoding session
+    ///
+    class WINSTD_API base64_dec
+    {
+    public:
+        inline base64_dec() : num(0) {};
+
+
+        ///
+        /// Decodes one block of information
+        ///
+        /// \param[out] out      Output
+        /// \param[in ] data     Data to decode
+        /// \param[in ] size     Length of `data` in bytes
+        /// \param[in ] is_last  Was this the last block of data?
+        ///
+        void decode(_Out_ std::vector<unsigned char> &out, _Out_ bool &is_last, _In_z_count_(size) const char *data, _In_ size_t size);
+
+
+        ///
+        /// Resets decoding session
+        ///
+        inline void clear()
+        {
+            num = 0;
+        }
+
+
+        ///
+        /// Returns maximum encoded size
+        ///
+        /// \param size  Number of bytes to encode
+        ///
+        /// \returns Maximum number of bytes for the encoded data of `size` length
+        ///
+        inline size_t dec_size(size_t size) const
+        {
+            return ((num + size + 3)/4)*3;
+        }
+
+
+    protected:
+        static inline size_t decode(_Inout_ std::vector<unsigned char> &out, _In_ const unsigned char buf[4])
+        {
+            out.push_back((unsigned char)(((buf[0] << 2) | (buf[1] >> 4)) & 0xff));
+            if (buf[2] < 64) {
+                out.push_back((unsigned char)(((buf[1] << 4) | (buf[2] >> 2)) & 0xff));
+                if (buf[3] < 64) {
+                    out.push_back((unsigned char)(((buf[2] << 6) | buf[3]) & 0xff));
+                    return 3;
+                } else
+                    return 2;
+            } else
+                return 1;
+        }
+
+
+    protected:
+        unsigned char buf[4];
+        size_t num;
+
+        static const unsigned char lookup[256];
+    };
+
+    /// @}
+}
+

include/WinStd/Common.h

@@ -29,6 +29,18 @@
 #include <string>
 
 
+///
+/// Public function calling convention
+///
+#if defined(WINSTD_DLL)
+#define WINSTD_API      __declspec(dllexport)
+#elif defined(WINSTD_DLLIMP)
+#define WINSTD_API      __declspec(dllimport)
+#else
+#define WINSTD_API
+#endif
+
+
 #ifndef WINSTD_STACK_BUFFER_BYTES
 ///
 /// Size of the stack buffer in bytes used for initial system function call