Files
ImHex-Patterns/patterns/7z.hexpat
Mrmaxmeier df97fc7257 patterns/includes: More misc cleanups (#353)
* patterns/zip: simplify find_sequence_in_range check

hex(340282366920938463463374607431768211455) =
0xffffffffffffffffffffffffffffffff

* patterns/7z: use Magic<> for signature, add pragma

* patterns/{nro, ogg}: use Magic<> for signature

* patterns/ttf: refactor, check magic

Use the "Field field @ position;" syntax instead of saving and restoring
the cursor position.

* readme: fix copy-paste error in pattern listing
2025-03-22 13:46:06 +01:00

94 lines
3.2 KiB
Rust

#pragma description 7z Archive
#pragma MIME application/x-7z-compressed
#pragma magic [ 37 7A BC AF 27 1C ] @ 0x00
import std.io;
import std.mem;
import std.math;
import type.magic;
enum Type:u8{
startPosition = 0x00, // Start position
sizeStartHeader = 0x20, // Size of start Header
};
struct StartHeader {
// File signature
type::Magic<"7z\xBC\xAF\x27\x1C"> signature [[color("FF0000")] ];
// Version format
u16 formatVersion [[color("00FF00")]];
// CRC start header
u32 crcOfTheFollowing20Bytes [[color("0000FF")]];
// Relative offset of End Header
u64 relativeOffsetEndHeader [[color("FFFF00")]];
// Length of End Header
u64 theLengthOfEndHeader [[color("00FFFF")]];
// CRC of End Ender
u32 crcOftheEndHeader [[color("FF00FF")]];
// File size calculation
u64 fileSize = relativeOffsetEndHeader + theLengthOfEndHeader + Type::sizeStartHeader;
// Absolute offset calculation End Header
u64 startEndHeader = relativeOffsetEndHeader + Type::sizeStartHeader;
};
StartHeader startheader @ Type::startPosition;
struct CompressedData {
// Start of compressed data
u8 startOfCompressedData[4] [[color("C0C0C0")]];
};
CompressedData compresseddata @ Type::sizeStartHeader;
struct EndHeader {
// Set padding to place End Header in right position
padding[startheader.relativeOffsetEndHeader];
// Mark link to meta block
u8 linkToMetaBlock [[color("FF0000")]];
// Mark all End Header
char fullEndHeader[startheader.theLengthOfEndHeader] [[color("63954A")]];
// Detect LZMA signature
u64 lzmaSignaturePosition = std::mem::find_sequence_in_range(0, addressof(fullEndHeader), addressof(fullEndHeader) + sizeof(fullEndHeader), 0x23, 0x03, 0x01, 0x01, 0x05, 0x5D);
// Mark positions if LZMA signature was detected
if(lzmaSignaturePosition != 0xFFFFFFFFFFFFFFFF){
u48 lzmaSignature @ lzmaSignaturePosition [[color("0000FF")]];
}
};
EndHeader endheader @ Type::sizeStartHeader;
std::print("Format Version {} ",startheader.formatVersion);
// Version verification
if(startheader.formatVersion == 0x0400){
std::print("Major Version 0x00 || 0 - Minor Version 0x04 || 4");
}
// Verification of the compressed method is LZMA, Bzip2 or LZMA2
if(compresseddata.startOfCompressedData[0] == Type::startPosition){
std::print("Compressed Method LZMA");
}else if(compresseddata.startOfCompressedData[0] == 0x42){
std::print("Compressed Method Bzip2");
}else{
std::print("Compressed Method LZMA2");
}
std::print("CRC Start Header 0x{:X}",startheader.crcOfTheFollowing20Bytes);
std::print("CRC End Header 0x{:X} ", startheader.crcOftheEndHeader);
std::print("CompressedData length 0x{:X} || {} bytes ",startheader.relativeOffsetEndHeader, startheader.relativeOffsetEndHeader);
std::print("Relative Offset of End Header 0x{:X} || {} bytes",startheader.relativeOffsetEndHeader, startheader.relativeOffsetEndHeader);
std::print("Offset to start End Header 0x{:X} || {} bytes",startheader.startEndHeader,startheader.startEndHeader);
std::print("End Header length 0x{:X} || {} bytes",startheader.theLengthOfEndHeader,startheader.theLengthOfEndHeader);
std::print("File size 0x{:X} || {} bytes",startheader.fileSize, startheader.fileSize);