Crate lde

Length Disassembler

Supports x86 and x86_64 up to SSE4.2.

Valid opcodes will be length disassembled correctly. Invalid opcodes may be rejected on a best-effort basis.

Examples

Gets the length of the first opcode in a byte slice:

let result = lde::X64.ld(b"\x40\x55\x48\x83\xEC\xFC\x00\x80");
assert_eq!(result, 2);

Iterates over the opcodes contained in a byte slice, returning the opcode and its virtual address:

let code = b"\x40\x55\x48\x83\xEC*\x00\x80";

for (opcode, va) in lde::X64.iter(code, 0x1000) {
    println!("{:x}: {}", va, opcode);
}

// 1000: 4055
// 1002: 4883EC2A

Find the opcode boundary after a minimum of 5 bytes:

// 1000: 56         push esi
// 1001: 33f6       xor esi,esi
// 1003: 57         push edi
// 1004: bfa0104000 mov edi,0x4010a0
// 1009: 85d2       test edx,edx
// 100b: 7410       je loc_0000001d
// 100d: 8bf2       mov esi,edx
// 100f: 8bfa       mov edi,edx

const INPUT_CODE: &[u8] = b"\x56\x33\xF6\x57\xBF\xA0\x10\x40\x00\x85\xD2\x74\x10\x8B\xF2\x8B\xFA";

// We'd like to overwrite the first 5 bytes with a jmp hook
// Find how many opcodes need to be copied for our hook to work

let mut count = 0;
for (opcode, _) in lde::X86.iter(INPUT_CODE, 0x1000) {
    count += opcode.len();
    if count >= 5 {
        break;
    }
}

// The answer is the first 4 opcodes, or 9 bytes

assert_eq!(count, 9);

Custom Display and Debug formatting including pretty printing support with the alternate flag:

let iter = lde::X64.iter(b"\x40\x55\x48\x83\xEC*\x00\x80", 0);

assert_eq!(format!("{:?}", iter), "[4055] [4883EC2A] 0080");
assert_eq!(format!("{:#?}", iter), "[40 55] [48 83 EC 2A] 00 80");
assert_eq!(format!("{:}", iter), "4055\n4883EC2A\n");
assert_eq!(format!("{:#}", iter), "40 55\n48 83 EC 2A\n");

Structs

Iter	Length disassembler iterator.
IterMut	Length disassembler mutable iterator.
OcBuilder	Opcode builder.
OpCode	Byte slice representing an opcode.
X64	Length disassembler for the x86_64 instruction set architecture.
X86	Length disassembler for the x86 instruction set architecture.

Traits

Int	Defines a type which can be safely constructed from a byte array of the same size.
Isa	Instruction set architecture.
Va	Virtual address type.