You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

76 lines
2.3 KiB

/*
* Copyright (C) 2017 The Android Open Source Project
*
* 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 <apdu/apdu.h>
#include <limits>
namespace android {
CommandApdu::CommandApdu(const uint8_t cla, const uint8_t ins, const uint8_t p1, const uint8_t p2,
const size_t lc, const size_t le) {
constexpr size_t headerSize = 4;
constexpr size_t shortLcMax = std::numeric_limits<uint8_t>::max();
constexpr size_t shortLeMax = std::numeric_limits<uint8_t>::max() + 1;
//constexpr size_t extendedLcMax = std::numeric_limits<uint16_t>::max();
constexpr size_t extendedLeMax = std::numeric_limits<uint16_t>::max() + 1;
const bool extended = lc > shortLcMax || le > shortLeMax;
const bool hasLc = lc > 0;
const bool hasLe = le > 0;
const size_t lcSize = hasLc ? (extended ? 3 : 1) : 0;
const size_t leSize = hasLe ? (extended ? (hasLc ? 2 : 3) : 1) : 0;
const size_t commandSize = headerSize + lcSize + lc + leSize;
mCommand.resize(commandSize, 0);
// All cases have the header
auto it = mCommand.begin();
*it++ = cla;
*it++ = ins;
*it++ = p1;
*it++ = p2;
// Cases 3 & 4 send data
if (hasLc) {
if (extended) {
*it++ = 0;
*it++ = 0xff & (lc >> 8);
}
*it++ = 0xff & lc;
mDataBegin = it;
it += lc;
mDataEnd = it;
} else {
mDataBegin = mDataEnd = mCommand.end();
}
// Cases 2 & 4 expect data back
if (hasLe) {
if (extended) {
if (!hasLc) {
*it++ = 0;
}
const bool isLeMax = le == extendedLeMax;
*it++ = (isLeMax ? 0 : 0xff & (le >> 8));
*it++ = (isLeMax ? 0 : 0xff & le);
} else {
*it++ = (le == shortLeMax ? 0 : 0xff & le);
}
}
}
} // namespace android