* Copyright (c) 2023 Huawei Device Co., Ltd.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "base64_helper.h"
#include <vector>
#include "log_print.h"
namespace OHOS {
namespace NativePreferences {
static const uint8_t base64Encoder[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static const uint8_t base64Decoder[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};
const uint32_t BASE64_DEST_UNIT_SIZE = 4;
const uint32_t BASE64_SRC_UNIT_SIZE = 3;
const uint32_t BASE64_ONE_PADDING = 1;
const uint32_t BASE64_TWO_PADDING = 2;
const uint8_t BASE64_INVALID = 0xFF;
const uint8_t BASE64_MASK1 = 0x03;
const uint8_t BASE64_MASK2 = 0x0F;
const uint8_t BASE64_MASK3 = 0x3F;
const uint8_t BASE64_SHIFT_HIBYTE = 2;
const uint8_t BASE64_SHIFT = 4;
const uint8_t BASE64_SHIFT_LOBYTE = 6;
std::string Base64Helper::Encode(const std::vector<uint8_t> &input)
{
std::string result = "";
uint32_t index = 0;
for (uint32_t len = input.size(); len > 0; len -= BASE64_SRC_UNIT_SIZE) {
result += base64Encoder[input.at(index) >> BASE64_SHIFT_HIBYTE];
uint8_t code = (input.at(index++) & BASE64_MASK1) << BASE64_SHIFT;
if (len > BASE64_ONE_PADDING) {
result += base64Encoder[code | (input.at(index) >> BASE64_SHIFT)];
code = (input.at(index++) & BASE64_MASK2) << BASE64_SHIFT_HIBYTE;
if (len > BASE64_TWO_PADDING) {
result += base64Encoder[code | (input.at(index) >> BASE64_SHIFT_LOBYTE)];
result += base64Encoder[input.at(index++) & BASE64_MASK3];
} else {
result += base64Encoder[code];
result += "=";
break;
}
} else {
result += base64Encoder[code];
result += "==";
break;
}
}
return result;
}
bool Base64Helper::Decode(const std::string &input, std::vector<uint8_t> &output)
{
if (input.length() % BASE64_DEST_UNIT_SIZE != 0) {
return false;
}
uint32_t index = 0;
std::vector<uint8_t> result {};
while (index < input.length()) {
uint8_t ch1 = base64Decoder[static_cast<uint8_t>(input.at(index++))];
uint8_t ch2 = base64Decoder[static_cast<uint8_t>(input.at(index++))];
if (ch1 == BASE64_INVALID || ch2 == BASE64_INVALID) {
return false;
}
result.emplace_back((ch1 << BASE64_SHIFT_HIBYTE) | (ch2 >> BASE64_SHIFT));
if (input.at(index) == '=') {
break;
}
uint8_t ch3 = base64Decoder[static_cast<uint8_t>(input.at(index++))];
if (ch3 == BASE64_INVALID) {
return false;
}
result.emplace_back((ch2 << BASE64_SHIFT) | (ch3 >> BASE64_SHIFT_HIBYTE));
if (input.at(index) == '=') {
break;
}
uint8_t ch4 = base64Decoder[static_cast<uint8_t>(input.at(index++))];
if (ch4 == BASE64_INVALID) {
return false;
}
result.emplace_back((ch3 << BASE64_SHIFT_LOBYTE) | ch4);
}
output = result;
return true;
}
}
}
