proton::binary b64_decode()

in shims/qpid-proton-cpp/src/qpidit/Base64.cpp [80:125]

• 38 lines of code
• 11 McCabe index (conditional complexity)

proton::binary b64_decode(std::string const& encoded_string) {
	int in_len = encoded_string.size();
	int i = 0;
	int j = 0;
	int in_ = 0;
	uint8_t char_array_4[4], char_array_3[3];
	proton::binary ret;

	while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
		char_array_4[i++] = encoded_string[in_]; in_++;
		if (i ==4) {
			for (i = 0; i <4; i++) {
				char_array_4[i] = b64_chars.find(char_array_4[i]);
			}

			char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
			char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
			char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

			for (i = 0; (i < 3); i++) {
				ret.push_back(char_array_3[i]);
			}
			i = 0;
		}
	}

	if (i) {
		for (j = i; j <4; j++) {
			char_array_4[j] = 0;
		}

		for (j = 0; j <4; j++) {
			char_array_4[j] = b64_chars.find(char_array_4[j]);
		}

		char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
		char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
		char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

		for (j = 0; (j < i - 1); j++) {
			ret.push_back(char_array_3[j]);
		}
	}

	return ret;
}