--- /dev/null
+// ============================================================================
+// Artsoft Retro-Game Library
+// ----------------------------------------------------------------------------
+// (c) 1995-2021 by Artsoft Entertainment
+// Holger Schemel
+// info@artsoft.org
+// https://www.artsoft.org/
+// ----------------------------------------------------------------------------
+// base64.c
+// ============================================================================
+
+/*
+
+ https://github.com/superwills/NibbleAndAHalf
+ base64.h -- Fast base64 encoding and decoding.
+ version 1.0.0, April 17, 2013 143a
+
+ Copyright (C) 2013 William Sherif
+
+ This software is provided 'as-is', without any express or implied
+ warranty. In no event will the authors be held liable for any damages
+ arising from the use of this software.
+
+ Permission is granted to anyone to use this software for any purpose,
+ including commercial applications, and to alter it and redistribute it
+ freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software
+ in a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+ 2. Altered source versions must be plainly marked as such, and must not be
+ misrepresented as being the original software.
+ 3. This notice may not be removed or altered from any source distribution.
+
+ William Sherif
+ will.sherif@gmail.com
+
+ YWxsIHlvdXIgYmFzZSBhcmUgYmVsb25nIHRvIHVz
+
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "base64.h"
+
+
+const static char* b64="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" ;
+
+// maps A=>0,B=>1..
+const static unsigned char unb64[]={
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //10
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //20
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //30
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //40
+ 0, 0, 0, 62, 0, 0, 0, 63, 52, 53, //50
+ 54, 55, 56, 57, 58, 59, 60, 61, 0, 0, //60
+ 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, //70
+ 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, //80
+ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, //90
+ 25, 0, 0, 0, 0, 0, 0, 26, 27, 28, //100
+ 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, //110
+ 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, //120
+ 49, 50, 51, 0, 0, 0, 0, 0, 0, 0, //130
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //140
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //150
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //160
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //170
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //180
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //190
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //200
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //210
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //220
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //230
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //240
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //250
+ 0, 0, 0, 0, 0, 0,
+}; // This array has 256 elements
+
+// Converts binary data of length=len to base64 characters.
+// Length of the resultant string is stored in flen
+// (you must pass pointer flen).
+char* base64( const void* binaryData, int len, int *flen )
+{
+ const unsigned char* bin = (const unsigned char*) binaryData ;
+ char* res ;
+
+ int rc = 0 ; // result counter
+ int byteNo ; // I need this after the loop
+
+ int modulusLen = len % 3 ;
+ int pad = ((modulusLen&1)<<1) + ((modulusLen&2)>>1) ; // 2 gives 1 and 1 gives 2, but 0 gives 0.
+
+ *flen = 4*(len + pad)/3 ;
+ res = (char*) malloc( *flen + 1 ) ; // and one for the null
+ if( !res )
+ {
+ puts( "ERROR: base64 could not allocate enough memory." ) ;
+ puts( "I must stop because I could not get enough" ) ;
+ return 0;
+ }
+
+ for( byteNo = 0 ; byteNo <= len-3 ; byteNo+=3 )
+ {
+ unsigned char BYTE0=bin[byteNo];
+ unsigned char BYTE1=bin[byteNo+1];
+ unsigned char BYTE2=bin[byteNo+2];
+ res[rc++] = b64[ BYTE0 >> 2 ] ;
+ res[rc++] = b64[ ((0x3&BYTE0)<<4) + (BYTE1 >> 4) ] ;
+ res[rc++] = b64[ ((0x0f&BYTE1)<<2) + (BYTE2>>6) ] ;
+ res[rc++] = b64[ 0x3f&BYTE2 ] ;
+ }
+
+ if( pad==2 )
+ {
+ res[rc++] = b64[ bin[byteNo] >> 2 ] ;
+ res[rc++] = b64[ (0x3&bin[byteNo])<<4 ] ;
+ res[rc++] = '=';
+ res[rc++] = '=';
+ }
+ else if( pad==1 )
+ {
+ res[rc++] = b64[ bin[byteNo] >> 2 ] ;
+ res[rc++] = b64[ ((0x3&bin[byteNo])<<4) + (bin[byteNo+1] >> 4) ] ;
+ res[rc++] = b64[ (0x0f&bin[byteNo+1])<<2 ] ;
+ res[rc++] = '=';
+ }
+
+ res[rc]=0; // NULL TERMINATOR! ;)
+ return res ;
+}
+
+unsigned char* unbase64( const char* ascii, int len, int *flen )
+{
+ const unsigned char *safeAsciiPtr = (const unsigned char*)ascii ;
+ unsigned char *bin ;
+ int cb=0;
+ int charNo;
+ int pad = 0 ;
+
+ if( len < 2 ) { // 2 accesses below would be OOB.
+ // catch empty string, return NULL as result.
+ puts( "ERROR: You passed an invalid base64 string (too short). You get NULL back." ) ;
+ *flen=0;
+ return 0 ;
+ }
+ if( safeAsciiPtr[ len-1 ]=='=' ) ++pad ;
+ if( safeAsciiPtr[ len-2 ]=='=' ) ++pad ;
+
+ *flen = 3*len/4 - pad ;
+ bin = (unsigned char*)malloc( *flen ) ;
+ if( !bin )
+ {
+ puts( "ERROR: unbase64 could not allocate enough memory." ) ;
+ puts( "I must stop because I could not get enough" ) ;
+ return 0;
+ }
+
+ for( charNo=0; charNo <= len - 4 - pad ; charNo+=4 )
+ {
+ int A=unb64[safeAsciiPtr[charNo]];
+ int B=unb64[safeAsciiPtr[charNo+1]];
+ int C=unb64[safeAsciiPtr[charNo+2]];
+ int D=unb64[safeAsciiPtr[charNo+3]];
+
+ bin[cb++] = (A<<2) | (B>>4) ;
+ bin[cb++] = (B<<4) | (C>>2) ;
+ bin[cb++] = (C<<6) | (D) ;
+ }
+
+ if( pad==1 )
+ {
+ int A=unb64[safeAsciiPtr[charNo]];
+ int B=unb64[safeAsciiPtr[charNo+1]];
+ int C=unb64[safeAsciiPtr[charNo+2]];
+
+ bin[cb++] = (A<<2) | (B>>4) ;
+ bin[cb++] = (B<<4) | (C>>2) ;
+ }
+ else if( pad==2 )
+ {
+ int A=unb64[safeAsciiPtr[charNo]];
+ int B=unb64[safeAsciiPtr[charNo+1]];
+
+ bin[cb++] = (A<<2) | (B>>4) ;
+ }
+
+ return bin ;
+}