GCrypt/GCryptCLI/src/DataIngestionLayer.cpp
2022-08-12 09:12:44 +02:00

368 lines
11 KiB
C++

#include "DataIngestionLayer.h"
#include "CommandlineInterface.h"
#include "DataFormatter.h"
#include "Bases.h"
#include <StringTools/StringTools.h>
#include <iostream>
#include <istream>
#include <fstream>
#include <sstream>
#include <cstring>
using namespace IO;
using namespace Leonetienne::StringTools;
void DataIngestionLayer::Init() {
// Set our istream
switch (Configuration::inputFrom) {
// Are we reading from stdin?
case Configuration::INPUT_FROM::STDIN:
// Redirect our istream to stdin
in = &std::cin;
break;
// Are we reading from a file?
case Configuration::INPUT_FROM::FILE:
// Open the file
ifs.open(
Configuration::inputFilename,
std::ios::in | std::ios::binary
);
// A little bit of error handling
if (!ifs.good()) {
throw std::runtime_error("Unable to open infilestream!");
}
// Redirect our istream to this infilestream
in = &ifs;
break;
// Are we reading from a parameter?
case Configuration::INPUT_FROM::PARAMETER:
// Create an instringstream with our parameter
iss = std::istringstream(
CommandlineInterface::Get()["--intext"].GetString()
);
// Redirect our istream to this instringstream
in = &iss;
break;
}
// Derive from our the current module if we're reading ciphertext or not
if (Configuration::activeModule == Configuration::MODULE::DECRYPTION) {
isReadingCiphertext = true;
}
else {
isReadingCiphertext = false;
}
initialized = true;
reachedEof = false;
nBlocksRead = 0;
return;
}
void DataIngestionLayer::Destruct() {
if (Configuration::inputFrom == Configuration::INPUT_FROM::FILE) {
ifs.close();
}
return;
}
void DataIngestionLayer::ReadBlock() {
if (!initialized) {
throw std::runtime_error("Attempted to read on uninitialized DataIngestionLayer!");
}
if (!reachedEof) {
// A block is this many digits wide, in encoding
const std::size_t blockWidth = blockLengthByBase[Configuration::formatIn];
// Iterate over the string, and parse all blocks
// We now have to differentiate between single-char digit sets (like hex),
// and multi-char digit sets (like uwu):
switch (Configuration::formatIn) {
case Configuration::IOBASE_FORMAT::BASE_BYTES:
case Configuration::IOBASE_FORMAT::BASE_2:
case Configuration::IOBASE_FORMAT::BASE_8:
case Configuration::IOBASE_FORMAT::BASE_10:
case Configuration::IOBASE_FORMAT::BASE_16:
case Configuration::IOBASE_FORMAT::BASE_64: {
// Easy case: Each digit is exactly one char in size.
// We can just calculate how many bytes we have to read.
// bytesRead is always of the correct length, 0-padded.
std::size_t n_bytes_read;
const std::string dataRead = ReadBytes(blockWidth, n_bytes_read);
// If we've read 0 bytes, this was the last block
// and it's completely empty. We can abort without doing anything.
// The ReadBytes function takes care of setting the reachedEof flag.
if (n_bytes_read == 0) {
return;
}
// If we are reading ciphertext
// make sure we've read enough bytes to compose a block.
if (
(isReadingCiphertext) &&
(n_bytes_read < blockWidth)
) {
throw std::runtime_error("DataIngestionLayer::ReadBlock() read an input-data fragment that is smaller than a data block should be. Is your cipher text incomplete?");
}
// This should decode to a block just like this.
Block newBlock;
// Special-case: We are reading cleartext (no ciphertext)
// cleartext is always base_bytes
if (!isReadingCiphertext) {
// When just reading cleartext-bytes, we also allow shorter strings
// than BLOCK_SIZE. These will just get zero-padded.
newBlock.FromTextString(dataRead);
}
else {
// Else: recode to a block.
newBlock = DataFormatter::DecodeFormat(
dataRead,
Configuration::formatIn
);
}
blocks.emplace(newBlock);
nBlocksRead++;
break;
}
case Configuration::IOBASE_FORMAT::BASE_UWU:
case Configuration::IOBASE_FORMAT::BASE_UGH: {
// The whole of Italy doesn't have as much spaghetti as this is...
// Hard case: Each digit is n digits long. Digits may vary in length.
// They are seperated by spaces.
// We have to parse them...
std::string overshoot = ""; // this is how much we've read too much in the last iteration
// Gets terminated by a break statement
while (1) {
// We'll read chunks of 64 bytes... This should be a good
// median, to also support small multi-byte-digit sets
std::size_t n_bytes_read = 0;
int lastDigitPos = -1; // Should point the the space BEFORE it. Relative to chunk.
std::size_t digitsCollected = 0;
std::stringstream digits;
bool foundBlock = false;
// Remember to prepend our overshoot from the previous iteration this chunk
std::string chunk = overshoot + ReadBytes(64, n_bytes_read);
// We should also strip all linebreaks from the chunk, that may be a result of manual stdin input.
chunk = StringTools::Replace(chunk, '\n', "");
// We can't just check for completeness by n_bytes_read...
// It can be any number of bytes, since any digit is n bytes long...
// Parse the 64-byte chunk string we've just fetched:
for (std::size_t i = 0; i < chunk.size(); i++) {
// If we are near the end, and have still not found a complete block, let's load an additional chunk
if (i == chunk.size() - 2) {
const std::string nextChunk = ReadBytes(64, n_bytes_read);
if (n_bytes_read != 0) {
chunk += StringTools::Replace(nextChunk, '\n', "");
}
}
// If i is on a space, or at the end of the chunk,
// and, at least one of i, or lastDigitPos is on a space,
if (
(
(chunk[i] == ' ') ||
(i == chunk.size() - 1)
) &&
(
(chunk[i] == ' ') ||
lastDigitPos >= 0 // This basically does the same as discribed, but safer, as its default value is -1.
)
){
digitsCollected++;
// We have found a digit. Let's store it away...
// We're putting them in a stringstream, to fit the format required by the data formatter...
// We have a slight edgecase if we're currently on the last char. Then we do NOT want to read one short.
// This is because we ususally stand on a seperator char (' '), which we do not want to extract. But in that case,
// in which we're standing on the last char, it could be not a seperator char.
// note: chunk[i] != ' ' can only be true if we're on the last char.
if (chunk[i] == ' ') {
digits <<
chunk.substr(
lastDigitPos + 1,
(int)i - lastDigitPos - 1
)
;
} else {
digits <<
chunk.substr(
lastDigitPos + 1,
(int)i - lastDigitPos
)
;
}
// Add a seperator, if its not the last
if (digitsCollected != blockWidth) {
digits << ' ';
}
lastDigitPos = i;
// Do we have enough digits to form a block?
if (digitsCollected == blockWidth) {
// We've found a complete block!
// Trim excess nullbytes off out digit string
const std::string digitString = std::string(
digits.str().data(),
strlen(digits.str().data())
);
// Decode it to a block object
const Block newBlock = DataFormatter::DecodeFormat(
digitString,
Configuration::formatIn
);
// Enqueue it to be processed by some module
blocks.emplace(newBlock);
nBlocksRead++;
foundBlock = true;
// Now we have to calculate how many bytes we've read TOO MANY.
// We have to trim this current chunk to be our new overshoot.
// If we still have more than a byte left, leave out the current seperator char
if (i < chunk.size() - 1) {
overshoot = chunk.substr(i+1); // Take all bytes from the next iterator, to the end
}
// Else: we are on the last char: there is no overshoot
else {
overshoot = "";
}
// Stop the for loop
break;
}
}
}
// Exit-condition:
// We have not found any block, not even any digit.
if ((!foundBlock) && (digitsCollected == 0)) {
break;
}
// Hard-abort: We have not finished reading a block
if (!foundBlock) {
throw std::runtime_error("DataIngestionLayer reached EOF whilst parsing multi-byte-digit block...");
}
}
break;
}
default:
throw std::invalid_argument("DataFormatter::StringToBlocks() has been passed an unknown base! No switch-case matched!");
}
}
return;
}
std::string DataIngestionLayer::ReadBytes(const std::size_t n, std::size_t& out_bytes_read) {
// Prepare a buffer to read to
char* buf = new char[n+1];
memset(buf, 0, (n+1) * sizeof(buf[0]));
// Read
in->read(buf, n * sizeof(buf[0]));
// Fetch how much we've read
out_bytes_read = in->gcount();
// Is this fewer bytes than got requested?
if (out_bytes_read < n) {
// Yes: EOF reached.
reachedEof = true;
}
// Translate buffer to a standard string
const std::string sbuf(buf, n);
delete[] buf;
// Return our buffer
return sbuf;
}
bool DataIngestionLayer::ReachedEOF() {
return reachedEof;
}
bool DataIngestionLayer::IsBlockReady() {
// We're not ready, if we haven't reached EOF, if we should buffer
// the input.
if (
(CommandlineInterface::Get().HasParam("--buffer-input")) &&
(!reachedEof)
) {
return false;
}
// If we're not buffering, just return whether or not
// we have any blocks...
return blocks.size() > 0;
}
bool DataIngestionLayer::IsFinished() {
return (reachedEof) && (blocks.size() == 0);
}
Block DataIngestionLayer::GetNextBlock() {
if (!IsBlockReady()) {
throw std::runtime_error("Attempted to get the next block, but there are none left!");
}
// Why... why not just return a T in pop()???
const Block popped = blocks.front();
blocks.pop();
return popped;
}
std::size_t DataIngestionLayer::NBlocksRead() {
return nBlocksRead;
}
std::istream* DataIngestionLayer::in;
std::ifstream DataIngestionLayer::ifs;
std::istringstream DataIngestionLayer::iss;
bool DataIngestionLayer::reachedEof = false;
bool DataIngestionLayer::initialized = false;
bool DataIngestionLayer::isReadingCiphertext;
std::size_t DataIngestionLayer::nBlocksRead = 0;
std::queue<Block> DataIngestionLayer::blocks;