base64: encoding

src/base64.cpp

@@ -18,3 +18,118 @@
 
 #include "base64.h"
 
+void base64_encode (const std::string& in, std::string&out, int cols)
+{
+	//note: it could be b64str[64], but we'd need -fpermissive
+	static const char b64str[65] =
+	    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+	int acc = 0, accbits = 0, idx = 0, idxmax = in.length(), col = 0;
+	out.clear();
+	out.reserve (idxmax + (4 * idxmax / 10) );
+	while (idx < idxmax) {
+		if (accbits < 6) {
+			acc = (acc << 8) | in[idx++];
+			accbits += 8;
+		}
+		while (accbits >= 6) {
+			accbits -= 6;
+			out.push_back (b64str[ (acc >> accbits) & 0x3f]);
+		}
+	}
+	if (accbits) {
+		out.push_back (b64str[ (acc << (6 - accbits) ) & 0x3f]);
+		if (accbits == 2) out.push_back ('=');
+		if (accbits <= 4) out.push_back ('=');
+	}
+}
+
+static void init_dec_str (char s[256])
+{
+	for (int i = 0; i < 256; ++i) s[i] = -1;
+
+	s['A'] = 0;
+	s['B'] = 1;
+	s['C'] = 2;
+	s['D'] = 3;
+	s['E'] = 4;
+	s['F'] = 5;
+	s['G'] = 6;
+	s['H'] = 7;
+	s['I'] = 8;
+	s['J'] = 9;
+
+	s['K'] = 10;
+	s['L'] = 11;
+	s['M'] = 12;
+	s['N'] = 13;
+	s['O'] = 14;
+	s['P'] = 15;
+	s['Q'] = 16;
+	s['R'] = 17;
+	s['S'] = 18;
+	s['T'] = 19;
+
+	s['U'] = 20;
+	s['V'] = 21;
+	s['W'] = 22;
+	s['X'] = 23;
+	s['Y'] = 24;
+	s['Z'] = 25;
+	s['a'] = 26;
+	s['b'] = 27;
+	s['c'] = 28;
+	s['d'] = 29;
+
+	s['e'] = 30;
+	s['f'] = 31;
+	s['g'] = 32;
+	s['h'] = 33;
+	s['i'] = 34;
+	s['j'] = 35;
+	s['k'] = 36;
+	s['l'] = 37;
+	s['m'] = 38;
+	s['n'] = 39;
+
+	s['o'] = 40;
+	s['p'] = 41;
+	s['q'] = 42;
+	s['r'] = 43;
+	s['s'] = 44;
+	s['t'] = 45;
+	s['u'] = 46;
+	s['v'] = 47;
+	s['w'] = 48;
+	s['x'] = 49;
+
+	s['y'] = 50;
+	s['z'] = 51;
+	s['0'] = 52;
+	s['1'] = 53;
+	s['2'] = 54;
+	s['3'] = 55;
+	s['4'] = 56;
+	s['5'] = 57;
+	s['6'] = 58;
+	s['7'] = 59;
+
+	s['8'] = 60;
+	s['9'] = 61;
+	s['+'] = 62;
+	s['/'] = 63;
+}
+
+bool base64_decode (const std::string& in, std::string&out)
+{
+	static char b64d[256];
+	static bool b64d_init = false;
+
+	if (!b64d_init) {
+		init_dec_str (b64d);
+		b64d_init = true;
+	}
+
+	return false;
+}
+

src/base64.h

@@ -21,7 +21,7 @@
 
 #include <string>
 
-void base64_encode (const std::string& in, std::string&out);
+void base64_encode (const std::string& in, std::string&out, int cols = 76);
 bool base64_decode (const std::string& in, std::string&out);
 
 #endif