1 files changed, 50 insertions, 0 deletions
diff --git a/goo/gbase64.cc b/goo/gbase64.cc
new file mode 100644
index 00000000..e0da77ff
--- /dev/null
+++ b/goo/gbase64.cc
@@ -0,0 +1,50 @@
+//========================================================================
+//
+// gbase64.cc
+//
+// Implementation of a base64 encoder, because another one did not immediately
+// avail itself.
+//
+// This file is licensed under the GPLv2 or later
+//
+// Copyright (C) 2018 Greg Knight <lyngvi@gmail.com>
+//
+//========================================================================
+
+#include "gbase64.h"
+#include <sstream>
+
+static void b64encodeTriplet(char output[4], unsigned char a, unsigned char b, unsigned char c)
+{
+    static const char* base64table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+    output[0] = base64table[((a >> 2) & 0x3f) ]; // upper 6 of first byte
+    output[1] = base64table[((a << 4) & 0x30) | ((b >> 4) & 0x0f)]; // lower 2 of first byte, upper 4 of second byte
+    output[2] = base64table[((b << 2) & 0x3c) | ((c >> 6) & 0x03)]; // lower 4 of second byte, upper 2 of third byte
+    output[3] = base64table[((c     ) & 0x3f)]; // lower 6 of third byte
+}
+
+std::string gbase64Encode(const void* input, size_t len)
+{
+    char quad[4];
+    size_t pos = 0;
+    std::stringstream buf;
+    auto bytes = static_cast<const unsigned char*>(input);
+    for ( ; pos + 3 <= len; pos += 3) {
+        b64encodeTriplet(quad, bytes[0], bytes[1], bytes[2]);
+        buf.write(&quad[0], 4);
+        bytes += 3;
+    }
+    switch (len - pos) {
+        case 1:
+            b64encodeTriplet(quad, bytes[0], 0, 0);
+            quad[2] = quad[3] = '=';
+            buf.write(&quad[0], 4);
+            break;
+        case 2:
+            b64encodeTriplet(quad, bytes[0], bytes[1], 0);
+            quad[3] = '=';
+            buf.write(&quad[0], 4);
+            break;
+    }
+    return buf.str();
+}