Method Base64Decode

source/Debugger.cpp:2351–2390

Decode base 64 data. aBuf and aInput may point to the same buffer.

// Decode base 64 data. aBuf and aInput may point to the same buffer.
size_t Debugger::Base64Decode(char *aBuf, const char *aInput, size_t aInputSize/* = -1*/)
{
	UINT_PTR buffer;
	size_t i, len = 0;

	if (aInputSize == -1) // Direct comparison since aInputSize is unsigned.
		aInputSize = strlen(aInput);

	while (aInputSize > 0 && aInput[aInputSize-1] == '=')
		--aInputSize;

	for (i = aInputSize; i > 3; i -= 4)
	{
		buffer	= BASE64_CHAR_TO_BINARY(aInput[0]) << 18 // L39: Fixed bad reliance on order of *side-effects++. [thanks fincs]
				| BASE64_CHAR_TO_BINARY(aInput[1]) << 12
				| BASE64_CHAR_TO_BINARY(aInput[2]) << 6
				| BASE64_CHAR_TO_BINARY(aInput[3]);
		aInput += 4;

		aBuf[len + 0] = (buffer >> 16) & 255;
		aBuf[len + 1] = (buffer >> 8) & 255;
		aBuf[len + 2] = buffer & 255;
		len += 3;
	}

	if (i > 1)
	{
		buffer  = BASE64_CHAR_TO_BINARY(aInput[0]) << 18
				| BASE64_CHAR_TO_BINARY(aInput[1]) << 12;
		if (i > 2)
			buffer |= BASE64_CHAR_TO_BINARY(aInput[2]) << 6;
		// aInput not incremented as it is not used below.

		aBuf[len++] = (buffer >> 16) & 255;
		if (i > 2)
			aBuf[len++] = (buffer >> 8) & 255;
	}
	aBuf[len] = '\0';
	return len;
}

//
// class Debugger::Buffer - simplifies memory management.