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Support extra files that do not have the same size and support file n…
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…ames that are not equally sized
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ruvmello committed Mar 11, 2024
1 parent 06261b3 commit 2ed532b
Showing 1 changed file with 61 additions and 20 deletions.
81 changes: 61 additions & 20 deletions src/main/kotlin/zip/ZIPArchiver.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -24,9 +24,13 @@ class ZIPArchiver(private val zipName: String,
private val debug: Boolean,
private val noCrc: Boolean,
private val numThreads: Int) {

private val datetime = LocalDateTime.now()
private val extraFieldString = "Made By Ruben Van Mello for his master's thesis at the University of Ghent on the generation of zip quines"

fun createZipLoop(inputFiles: List<String>) {
assert(inputFiles.size == 2) {"A quine loop only supports two files maximum as of the current implementation"}

val zipNames = inputFiles.map { it.substringBeforeLast('.').substringAfterLast('/') + ".zip" }
val zipName = zipNames[0]
val zipName2 = zipNames[1]
Expand All @@ -36,19 +40,51 @@ class ZIPArchiver(private val zipName: String,
val crc32Bruteforcer = CRC32Bruteforcer(numThreads)

// Get all lh's, compressed streams, cd's
val (localHeaders, dataStreams, centralDirectories) = compressFiles(inputFiles, loopEnabled = true)
var (localHeaders, dataStreams, centralDirectories) = compressFiles(inputFiles, loopEnabled = true)
var headers = localHeaders.indices.map { localHeaders[it] + dataStreams[it] }
print("Generating the quine...\r")

// Make header sizes equal
val differenceHeader = headers[0].size - headers[1].size
var headerExtraField = ""
var headerExtraField2 = ""
if (differenceHeader < 0) {
headerExtraField = this.extraFieldString.substring(0, -differenceHeader)
} else if (differenceHeader > 0) {
headerExtraField2 = this.extraFieldString.substring(0, differenceHeader)
}

// Add data in extraField so that each lh + data is equal in size
val newLocalHeaders = listOf(
localHeaders[0].copyOfRange(0, 28) + getByteArrayOf2Bytes(headerExtraField.length) + localHeaders[0].copyOfRange(30, localHeaders[0].size) + headerExtraField.toByteArray(),
localHeaders[1].copyOfRange(0, 28) + getByteArrayOf2Bytes(headerExtraField2.length) + localHeaders[1].copyOfRange(30, localHeaders[1].size) + headerExtraField2.toByteArray()
)

// lhQuine and lhQuine2 must have the same size, so if filename is not equally long, add bytes in the extraField
val differenceFooter = zipName.length - zipName2.length
var footerExtraField = ""
var footerExtraField2 = ""
if (differenceFooter < 0) {
footerExtraField = this.extraFieldString.substring(0, -differenceFooter)
} else if (differenceFooter > 0) {
footerExtraField2 = this.extraFieldString.substring(0, differenceFooter)
}

val headers = localHeaders.indices.map { localHeaders[it] + dataStreams[it] }
// Add data in extraField so that each lh + data is equal in size
centralDirectories = listOf(
centralDirectories[0].copyOfRange(0, 30) + getByteArrayOf2Bytes(footerExtraField.length) + centralDirectories[0].copyOfRange(32, centralDirectories[0].size) + footerExtraField.toByteArray(),
centralDirectories[1].copyOfRange(0, 30) + getByteArrayOf2Bytes(footerExtraField2.length) + centralDirectories[1].copyOfRange(32, centralDirectories[1].size) + footerExtraField2.toByteArray()
)

headers = newLocalHeaders.indices.map { newLocalHeaders[it] + dataStreams[it] }
val header = headers[0]
val cd = centralDirectories[0]

print("Generating the quine...\r")

// Generate quine of the right size, but the header will still be wrong
var lhQuine = this.getLocalFileHeader(zipName, 0, 0)
var lhQuine2 = this.getLocalFileHeader(zipName2, 0, 0)
var cdQuine = this.getCentralDirectoryFileHeader(zipName, 0, 0, 0)
var cdQuine2 = this.getCentralDirectoryFileHeader(zipName2, 0, 0, 0)
var lhQuine = this.getLocalFileHeader(zipName, 0, 0, extraField = footerExtraField)
var lhQuine2 = this.getLocalFileHeader(zipName2, 0, 0, extraField = footerExtraField2)
var cdQuine = this.getCentralDirectoryFileHeader(zipName, 0, 0, 0, extraField = footerExtraField)
var cdQuine2 = this.getCentralDirectoryFileHeader(zipName2, 0, 0, 0, extraField = footerExtraField2)
var endCd = this.getEndOfCentralDirectoryRecord(1, 0, 0)
var footer = cd + cdQuine + endCd
var footer2 = centralDirectories[1] + cdQuine2 + endCd
Expand All @@ -59,10 +95,10 @@ class ZIPArchiver(private val zipName: String,
val offset = fullZipFile.size + footer.size + lhQuine.size + quine.size
val totalSize = fullZipFile.size + footer.size + lhQuine.size + quine.size + footer.size

lhQuine = this.getLocalFileHeader(zipName, quine.size, totalSize)
lhQuine2 = this.getLocalFileHeader(zipName2, quine.size, totalSize)
cdQuine = this.getCentralDirectoryFileHeader(zipName, quine.size, header.size + footer.size, totalSize)
cdQuine2 = this.getCentralDirectoryFileHeader(zipName2, quine.size, header.size + footer.size, totalSize)
lhQuine = this.getLocalFileHeader(zipName, quine.size, totalSize, extraField = footerExtraField)
lhQuine2 = this.getLocalFileHeader(zipName2, quine.size, totalSize, extraField = footerExtraField2)
cdQuine = this.getCentralDirectoryFileHeader(zipName, quine.size, header.size + footer.size, totalSize, extraField = footerExtraField)
cdQuine2 = this.getCentralDirectoryFileHeader(zipName2, quine.size, headers[1].size + footer2.size, totalSize, extraField = footerExtraField2)
endCd = this.getEndOfCentralDirectoryRecord(
2,
fullZipFile.size + footer.size + lhQuine.size + quine.size + cd.size + cdQuine.size - offset,
Expand Down Expand Up @@ -538,7 +574,7 @@ class ZIPArchiver(private val zipName: String,
// Ly+z
val lastRepeats = calculateLastQuineRepeatLoop(distanceToFooter + 40, footer.size - lhSize) // + 20 for L4, +20 for R4
getLiteralWithSize(lastRepeats.size).forEach { literal.add(LZ77Literal(it.toUByte())) }
println("Distance: " + (distanceToFooter + 40) + ", size: " + (footer2.size - lhSize))

// Add to zip
bytesToAdd = huffman.encodeStoredBlock(literal, false)
quineData += bytesToAdd
Expand Down Expand Up @@ -673,7 +709,7 @@ class ZIPArchiver(private val zipName: String,
* @param crc32 the crc-32 value that needs to be included in the header
* @return the local file header
*/
private fun getLocalFileHeader(fileName: String, compressedSize: Int, uncompressedSize: Int, crc32: ByteArray = byteArrayOf(0x0, 0x0, 0x0, 0x0)): ByteArray {
private fun getLocalFileHeader(fileName: String, compressedSize: Int, uncompressedSize: Int, crc32: ByteArray = byteArrayOf(0x0, 0x0, 0x0, 0x0), extraField: String = ""): ByteArray {
var data = byteArrayOf()

// https://users.cs.jmu.edu/buchhofp/forensics/formats/pkzip.html
Expand All @@ -683,13 +719,16 @@ class ZIPArchiver(private val zipName: String,
data += zipSignature
data += zipVersion

val commonHeader = this.writeCommonHeader(fileName.length, compressedSize, uncompressedSize, crc32)
val commonHeader = this.writeCommonHeader(fileName.length, compressedSize, uncompressedSize, crc32, extraField.length)
data += commonHeader

// File name
data += fileName.encodeToByteArray()

// Extra field content
if (extraField.isNotEmpty()) {
data += extraField.toByteArray()
}

return data
}
Expand Down Expand Up @@ -725,7 +764,7 @@ class ZIPArchiver(private val zipName: String,
* @param crc32 the crc-32 value that needs to be included in the header
* @return the central directory header
*/
private fun getCentralDirectoryFileHeader(fileName: String, compressedSize: Int, localHeaderOffset: Int, uncompressedSize: Int, crc32: ByteArray = byteArrayOf(0x0, 0x0, 0x0, 0x0)): ByteArray {
private fun getCentralDirectoryFileHeader(fileName: String, compressedSize: Int, localHeaderOffset: Int, uncompressedSize: Int, crc32: ByteArray = byteArrayOf(0x0, 0x0, 0x0, 0x0), extraField: String = ""): ByteArray {
var data = byteArrayOf()

// https://users.cs.jmu.edu/buchhofp/forensics/formats/pkzip.html
Expand All @@ -737,7 +776,7 @@ class ZIPArchiver(private val zipName: String,
data += zipVersionMadeBy
data += zipVersionNeededToExtract

val commonHeader = this.writeCommonHeader(fileName.length, compressedSize, uncompressedSize, crc32)
val commonHeader = this.writeCommonHeader(fileName.length, compressedSize, uncompressedSize, crc32, extraField.length)
data += commonHeader

val comment = ""
Expand All @@ -763,7 +802,9 @@ class ZIPArchiver(private val zipName: String,
data += fileName.encodeToByteArray()

// Extra field content
// zip.appendBytes(getByteArrayOf2Bytes(0))
if (extraField.isNotEmpty()) {
data += extraField.toByteArray()
}

// File comment
if (comment.isNotEmpty())
Expand Down Expand Up @@ -823,7 +864,7 @@ class ZIPArchiver(private val zipName: String,
* @param crc32 the crc-32 value that needs to be included in the header
* @return the part that is common of the central directory and the local file header
* */
private fun writeCommonHeader(fileNameLength: Int, compressedSize: Int, uncompressedSize: Int, crc32: ByteArray): ByteArray {
private fun writeCommonHeader(fileNameLength: Int, compressedSize: Int, uncompressedSize: Int, crc32: ByteArray, extraFieldSize: Int): ByteArray {
var data = byteArrayOf()

val zipFlags: ByteArray = byteArrayOf(0x00, 0x00)
Expand Down Expand Up @@ -857,7 +898,7 @@ class ZIPArchiver(private val zipName: String,
data += getByteArrayOf2Bytes(fileNameLength)

// Extra field length
data += getByteArrayOf2Bytes(0)
data += getByteArrayOf2Bytes(extraFieldSize)

return data
}
Expand Down

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