/**
* Relational pipes
* Copyright © 2021 František Kučera (Frantovo.cz, GlobalCode.info)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <memory>
#include <vector>
#include <array>
#include <sstream>
#include <regex>
#include "ASN1Reader.h"
namespace relpipe {
namespace in {
namespace asn1 {
namespace lib {
/**
* Reads ASN.1 data encoded as BER (DER, CER).
*/
class BasicASN1Reader : public ASN1Reader {
private:
bool started = false;
class BasicHeader : public ASN1ContentHandler::Header {
public:
bool definiteLength;
size_t length;
};
class LevelMetadata {
public:
bool definiteLength;
size_t length;
size_t start;
};
std::vector<LevelMetadata> level;
void checkRemainingItems() {
if (level.size()) {
LevelMetadata& l = level.back();
if (l.definiteLength && l.length == getBytesRead() - l.start) {
level.pop_back();
handlers.writeCollectionEnd();
checkRemainingItems(); // multiple collections may end at the same point
}
}
}
BasicHeader readHeader() {
using TagClass = ASN1ContentHandler::TagClass;
using PC = ASN1ContentHandler::PC;
BasicHeader h;
memset(&h, 0, sizeof (h)); // TODO: remove, not needed
uint8_t tagByte;
read(&tagByte, 1);
h.tagClass = (TagClass) (tagByte >> 6);
h.pc = (PC) ((tagByte >> 5) & 1);
h.tag = tagByte & (0xFF >> 3);
if (h.tag == 31) { // all five tag bits are set → tag number (greater than 30) is encoded in following octets
h.tag = 0;
uint8_t moreTag = 0;
do {
read(&moreTag, 1);
h.tag = h.tag << 7 | (moreTag & (0xFF >> 1));
} while (moreTag & (1 << 7));
}
uint8_t lengthByte;
read(&lengthByte, 1);
if (lengthByte >> 7 == 0) {
// definite short
h.definiteLength = true;
h.length = lengthByte;
} else if (lengthByte == 0b10000000) {
// indefinite
h.definiteLength = false;
h.length = 0;
} else if (lengthByte == 0xFF) {
throw relpipe::writer::RelpipeWriterException(L"ASN.1 lengthByte == 0xFF (reserved value)"); // TODO: better exception
} else {
// definite long
h.definiteLength = true;
h.length = 0;
std::vector<uint8_t> lengthBytes(lengthByte & 0b01111111, 0);
read(lengthBytes.data(), lengthBytes.size());
for (uint8_t l : lengthBytes) h.length = (h.length << 8) + l;
}
return h;
}
void readNext() {
using TagClass = ASN1ContentHandler::TagClass;
using PC = ASN1ContentHandler::PC;
checkRemainingItems();
BasicHeader typeHeader = readHeader();
// commit(); // TODO: commit here and recover later instead of rollback?
if (!started) {
handlers.writeStreamStart();
started = true;
}
// TODO: check tagClass and pc
// TODO: constants, more types
if (typeHeader.tag == UniversalType::EndOfContent && typeHeader.tagClass == TagClass::Universal && typeHeader.pc == PC::Primitive) {
handlers.writeCollectionEnd();
} else if (typeHeader.tag == UniversalType::Sequence) {
level.push_back({typeHeader.definiteLength, typeHeader.length, getBytesRead()}); // TODO: transaction
handlers.writeCollectionStart(typeHeader);
} else if (typeHeader.tag == UniversalType::Set) {
level.push_back({typeHeader.definiteLength, typeHeader.length, getBytesRead()}); // TODO: transaction
handlers.writeCollectionStart(typeHeader);
} else if (typeHeader.pc == PC::Constructed) {
level.push_back({typeHeader.definiteLength, typeHeader.length, getBytesRead()}); // TODO: transaction
handlers.writeCollectionStart(typeHeader);
} else if (typeHeader.tag == UniversalType::Null && typeHeader.length == 0) {
handlers.writeNull(typeHeader);
} else if (typeHeader.tag == UniversalType::Boolean && typeHeader.definiteLength && typeHeader.length == 1) {
bool value;
read((uint8_t*) & value, 1);
handlers.writeBoolean(typeHeader, value);
} else if (typeHeader.tag == UniversalType::Integer && typeHeader.tagClass == TagClass::Universal && typeHeader.definiteLength) {
// TODO: check available bytes before allocating buffer
std::vector<uint8_t> value(typeHeader.length, 0x00);
read(value.data(), typeHeader.length);
handlers.writeInteger(typeHeader, ASN1ContentHandler::Integer(value));
} else if (typeHeader.tag == UniversalType::ObjectIdentifier && typeHeader.tagClass == TagClass::Universal && typeHeader.definiteLength) {
std::vector<uint8_t> value(typeHeader.length, 0x00);
read(value.data(), typeHeader.length);
handlers.writeOID(typeHeader,{value});
} else if (typeHeader.tag == UniversalType::UTF8String && typeHeader.tagClass == TagClass::Universal && typeHeader.definiteLength) {
// TODO: check available bytes before allocating buffer
std::string s;
s.resize(typeHeader.length);
read((uint8_t*) s.data(), typeHeader.length);
handlers.writeTextString(typeHeader, s);
} else if (typeHeader.tag == UniversalType::PrintableString && typeHeader.tagClass == TagClass::Universal && typeHeader.definiteLength) {
// TODO: check encoding
// TODO: check available bytes before allocating buffer
std::string s;
s.resize(typeHeader.length);
read((uint8_t*) s.data(), typeHeader.length);
handlers.writeTextString(typeHeader, s);
} else if (typeHeader.tag == UniversalType::OctetString && typeHeader.tagClass == TagClass::Universal && typeHeader.definiteLength) {
// TODO: check available bytes before allocating buffer
std::string s;
s.resize(typeHeader.length);
read((uint8_t*) s.data(), typeHeader.length);
handlers.writeOctetString(typeHeader, s);
} else if (typeHeader.tag == UniversalType::BitString && typeHeader.tagClass == TagClass::Universal && typeHeader.definiteLength) {
// TODO: check available bytes before allocating buffer
std::string s;
s.resize(typeHeader.length);
read((uint8_t*) s.data(), typeHeader.length);
std::vector<bool> bits;
// TODO: throw exception on wrong padding or insufficient length?
if (s.size() > 1) {
uint8_t padding = s[0];
for (uint8_t j = padding; j < 8; j++) bits.push_back(s.back() & 1 << j);
for (size_t i = s.size() - 2; i > 0; i--) for (uint8_t j = 0; j < 8; j++) bits.push_back(s[i] & 1 << j);
}
handlers.writeBitString(typeHeader, bits);
} else if (typeHeader.tag == UniversalType::UTCTime && typeHeader.tagClass == TagClass::Universal && typeHeader.definiteLength) {
// TODO: check available bytes before allocating buffer
// TODO: check encoding
std::string s;
s.resize(typeHeader.length);
read((uint8_t*) s.data(), typeHeader.length);
ASN1ContentHandler::DateTime dateTime;
std::smatch match;
if (std::regex_match(s, match, std::regex("([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})?(Z|([+-][0-9]{2})'?([0-9]{2})'?)"))) {
// Supported UTCTime formats:
// YYMMDDhhmmZ
// YYMMDDhhmmssZ
// YYMMDDhhmm+hhmm
// YYMMDDhhmm-hhmm
// YYMMDDhhmmss+hhmm
// YYMMDDhhmmss-hhmm
int i = 1;
uint32_t year = std::stoi(match[i++]);
dateTime.year = year < 50 ? 2000 + year : 1900 + year;
dateTime.month = std::stoi(match[i++]);
dateTime.day = std::stoi(match[i++]);
dateTime.hour = std::stoi(match[i++]);
dateTime.minute = std::stoi(match[i++]);
dateTime.precision = match[i].length() ? ASN1ContentHandler::DateTime::Precision::Second : ASN1ContentHandler::DateTime::Precision::Minute;
dateTime.second = match[i].length() ? std::stoi(match[i++]) : 0;
if (match[i++] != "Z") {
dateTime.timezoneHour = std::stoi(match[i++]);
dateTime.timezoneMinute = std::stoi(match[i++]);
}
handlers.writeDateTime(typeHeader, dateTime);
} else {
throw std::invalid_argument("Unsupported UTCTime format: " + s); // TODO: better exception
}
} else if (typeHeader.tag == UniversalType::GeneralizedTime && typeHeader.tagClass == TagClass::Universal && typeHeader.definiteLength) {
// TODO: check available bytes before allocating buffer
std::string s;
s.resize(typeHeader.length);
read((uint8_t*) s.data(), typeHeader.length);
ASN1ContentHandler::DateTime dateTime;
std::smatch match;
if (std::regex_match(s, match, std::regex("([0-9]{4})([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})(\\.([0-9]{1,3}))?(Z|([+-][0-9]{2})'?([0-9]{2})'?)"))) {
int i = 1;
dateTime.year = std::stoi(match[i++]);
dateTime.month = std::stoi(match[i++]);
dateTime.day = std::stoi(match[i++]);
dateTime.hour = std::stoi(match[i++]);
dateTime.minute = std::stoi(match[i++]);
dateTime.second = match[i].length() ? std::stoi(match[i++]) : 0;
dateTime.precision = match[i++].length() ? ASN1ContentHandler::DateTime::Precision::Nanosecond : ASN1ContentHandler::DateTime::Precision::Second;
if (match[i].length() == 1) dateTime.nanosecond = std::stoi(match[i++]) * 100 * 1000000;
else if (match[i].length() == 2) dateTime.nanosecond = std::stoi(match[i++]) * 10 * 1000000;
else if (match[i].length() == 3) dateTime.nanosecond = std::stoi(match[i++]) * 1000000;
else i++;
if (match[i++] != "Z") {
dateTime.timezoneHour = std::stoi(match[i++]);
dateTime.timezoneMinute = std::stoi(match[i++]);
}
handlers.writeDateTime(typeHeader, dateTime);
} else {
throw std::invalid_argument("Unsupported GeneralizedTime format: " + s); // TODO: better exception
}
} else {
// TODO: do not skip, parse
std::vector<uint8_t> temp(typeHeader.length, 0);
read(temp.data(), typeHeader.length);
// TODO: recover transaction?
std::stringstream description;
description << "value:"
<< " tag = " << typeHeader.tag
<< " tagClass = " << (int) typeHeader.tagClass
<< " pc = " << (int) typeHeader.pc
<< " length = " << typeHeader.length
<< " definite = " << (typeHeader.definiteLength ? "true" : "false");
handlers.writeTextString(typeHeader, description.str());
}
commit();
}
protected:
void update() override {
while (true) readNext();
}
public:
void close() override {
checkRemainingItems();
// TODO: check the bytes remaining in the buffer
if (started) handlers.writeStreamEnd();
}
};
}
}
}
}