libmwemu 0.25.4

x86 32/64bits and system internals emulator, for securely emulating malware and other stuff.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117

use crate::color;
use crate::emu::Emu;
use iced_x86::Instruction;

pub fn execute(emu: &mut Emu, ins: &Instruction, instruction_sz: usize, _rep_step: bool) -> bool {
    // SSE2 CMPSD (scalar-double compare) shares this mnemonic with the string
    // CMPSD; the SSE form is the one with three operands (xmm, xmm/m64, imm8).
    if ins.op_count() == 3 {
        emu.show_instruction(
            color!("Cyan"),
            &crate::emu::decoded_instruction::DecodedInstruction::X86(*ins),
        );
        let dest = emu.get_operand_xmm_value_128(ins, 0, true).unwrap_or(0);
        let src = emu.get_operand_xmm_value_128(ins, 1, true).unwrap_or(0);
        let pred = emu.get_operand_value(ins, 2, true).unwrap_or(0) as u8 & 7;
        let a = f64::from_bits((dest & 0xffff_ffff_ffff_ffff) as u64);
        let b = f64::from_bits((src & 0xffff_ffff_ffff_ffff) as u64);
        let t = match pred {
            0 => a == b,
            1 => a < b,
            2 => a <= b,
            3 => a.is_nan() || b.is_nan(),
            4 => !(a == b),
            5 => !(a < b),
            6 => !(a <= b),
            _ => !a.is_nan() && !b.is_nan(),
        };
        let low: u128 = if t { 0xffff_ffff_ffff_ffff } else { 0 };
        let result = (dest & !(0xffff_ffff_ffff_ffffu128)) | low;
        emu.set_operand_xmm_value_128(ins, 0, result);
        return true;
    }

    let value0: u32;
    let value1: u32;

    if emu.rep.is_some() {
        if emu.rep.unwrap() == 0 || emu.cfg.verbose >= 3 {
            emu.show_instruction(
                color!("LightCyan"),
                &crate::emu::decoded_instruction::DecodedInstruction::X86(*ins),
            );
        }
    } else {
        emu.show_instruction(
            color!("LightCyan"),
            &crate::emu::decoded_instruction::DecodedInstruction::X86(*ins),
        );
    }

    if emu.cfg.is_x64() {
        value0 = match emu.maps.read_dword(emu.regs().rsi) {
            Some(v) => v,
            None => {
                log::trace!("cannot read rsi");
                return false;
            }
        };
        value1 = match emu.maps.read_dword(emu.regs().rdi) {
            Some(v) => v,
            None => {
                log::trace!("cannot read rdi");
                return false;
            }
        };

        if emu.flag_df() {
            emu.regs_mut().rsi -= 4;
            emu.regs_mut().rdi -= 4;
        } else {
            emu.regs_mut().rsi += 4;
            emu.regs_mut().rdi += 4;
        }
    } else {
        // 32bits
        value0 = match emu.maps.read_dword(emu.regs().get_esi()) {
            Some(v) => v,
            None => {
                log::trace!("cannot read esi");
                return false;
            }
        };
        value1 = match emu.maps.read_dword(emu.regs().get_edi()) {
            Some(v) => v,
            None => {
                log::trace!("cannot read edi");
                return false;
            }
        };

        if emu.flag_df() {
            let esi = emu.regs().get_esi() - 4;
            let edi = emu.regs().get_edi() - 4;
            emu.regs_mut().set_esi(esi);
            emu.regs_mut().set_edi(edi);
        } else {
            let esi = emu.regs().get_esi() + 4;
            let edi = emu.regs().get_edi() + 4;
            emu.regs_mut().set_esi(esi);
            emu.regs_mut().set_edi(edi);
        }
    }

    emu.flags_overwrite_mut()
        .sub32(value0 as u64, value1 as u64);

    if emu.cfg.verbose >= 2 {
        if value0 > value1 {
            log::trace!("\tcmp: 0x{:x} > 0x{:x}", value0, value1);
        } else if value0 < value1 {
            log::trace!("\tcmp: 0x{:x} < 0x{:x}", value0, value1);
        } else {
            log::trace!("\tcmp: 0x{:x} == 0x{:x}", value0, value1);
        }
    }
    true
}