ptrauth-sys 1.0.0

A library for stripping ARMv8.3 PAC signatures from pointers.
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

use std::path::PathBuf;
use std::{env, fs};

fn main() {
    let mut sdk_path = String::new();
    if let Ok(sysroot) = env::var("SYSROOT") {
        sdk_path = sysroot.to_owned();
    } else if let Ok(dragonbuild) = env::var("DRAGONBUILD") {
        let dragonbuild_frameworks: PathBuf = [dragonbuild.to_owned(), "frameworks".to_string()]
            .iter()
            .collect();
        println!(
            "cargo:rustc-link-search=framework={}",
            dragonbuild_frameworks.display()
        );
        let dragonbuild_sdks: PathBuf =
            [dragonbuild, "sdks".to_string(), "iPhoneOS.sdk".to_string()]
                .iter()
                .collect();
        sdk_path = dragonbuild_sdks.into_os_string().into_string().unwrap();
    } else if let Ok(theos) = env::var("THEOS") {
        let theos_frameworks: PathBuf = [theos.to_owned(), "vendor".to_string(), "lib".to_string()]
            .iter()
            .collect();
        println!(
            "cargo:rustc-link-search=framework={}",
            theos_frameworks.display()
        );
        let theos_sdks: PathBuf = [theos, "sdks".to_string(), "iPhoneOS.sdk".to_string()]
            .iter()
            .collect();
        sdk_path = theos_sdks.into_os_string().into_string().unwrap();
    }

    if env::var("CARGO_FEATURE_ARM64E").is_ok() {
        let base_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
        let librustsupport: PathBuf = [base_dir, "src".to_string(), "lib.c".to_string()]
            .iter()
            .collect();
        cc::Build::new()
            .file(librustsupport.as_path())
            .compiler("clang")
            .no_default_flags(true)
            .static_flag(true)
            .warnings(false)
            .flag("-isysroot")
            .flag(&sdk_path)
            .flag("-target")
            .flag("arm64e-apple-ios")
            .flag("-arch")
            .flag("arm64e")
            .compile("ptrauth");
        let afile: PathBuf = [env::var("OUT_DIR").unwrap(), "libptrauth.a".to_string()]
            .iter()
            .collect();

        // Now, time for the big hack.
        // Forgive me for this.
        if let Ok(mut bytes) = fs::read(&afile) {
            let to_find: &[u8] = &[0xCF, 0xFA, 0xED, 0xFE, 0x0C, 0x00, 0x00, 0x01, 0x02]; // MACH-O magic + CPUTYPE_ARM_ANY + CPUSUBTYPE_ARM64E
            let headerstart = bytes
                .windows(to_find.len())
                .position(|w| w == to_find)
                .unwrap_or(0xC8);
            bytes[headerstart + (to_find.len() - 1)] = 0x00;
            fs::write(&afile, &bytes).expect("Errored writing librustsupport file!");
        }
    }
}