Implement sys.get_os (#238)

* Implemented, tested, documented.

* Fix lib test.

docs/_docs/user-guide/eldritch.md

@@ -330,6 +330,20 @@ The <b>sys.get_ip</b> method returns a list of network interfaces as a dictionar
 ]
 ```
 
+### sys.get_os
+`sys.get_os() -> Dict`
+
+The <b>sys.get_os</b> method returns a dictionary that describes the current systems OS.
+An example is below:
+
+```json
+{
+    "arch": "x86_64",
+    "desktop_env": "Unknown: Unknown",
+    "distro": "Debian GNU/Linux 10 (buster)",
+    "platform": "Linux"
+}
+
 ### sys.is_linux
 `sys.is_linux() -> bool`
 

implants/lib/eldritch/Cargo.toml

@@ -35,6 +35,7 @@ windows-sys = { workspace = true, features = [
     "Win32_System_Diagnostics_Debug",
     "Win32_Security",
 ]}
+whoami = { workspace = true }
 
 [dev-dependencies]
 httptest = { workspace = true }

implants/lib/eldritch/src/lib.rs

@@ -172,7 +172,7 @@ mod tests {
             r#"
 dir(file) == ["append", "compress", "copy", "download", "exists", "hash", "is_dir", "is_file", "mkdir", "read", "remove", "rename", "replace", "replace_all", "template", "timestomp", "write"]
 dir(process) == ["kill", "list", "name"]
-dir(sys) == ["dll_inject", "exec", "get_ip", "is_linux", "is_macos", "is_windows", "shell"]
+dir(sys) == ["dll_inject", "exec", "get_ip", "get_os", "is_linux", "is_macos", "is_windows", "shell"]
 dir(pivot) == ["arp_scan", "bind_proxy", "ncat", "port_forward", "port_scan", "smb_exec", "ssh_exec", "ssh_password_spray"]
 dir(assets) == ["copy","list"]
 "#,

implants/lib/eldritch/src/sys.rs

@@ -1,5 +1,6 @@
 mod exec_impl;
 mod get_ip_impl;
+mod get_os_impl;
 mod is_linux_impl;
 mod is_windows_impl;
 mod is_macos_impl;
@@ -62,6 +63,10 @@ fn methods(builder: &mut MethodsBuilder) {
         if false { println!("Ignore unused this var. _this isn't allowed by starlark. {:?}", this); }
         exec_impl::exec(starlark_heap, path, args, disown)
     }
+    fn get_os<'v>(this: SysLibrary, starlark_heap: &'v Heap) -> anyhow::Result<Dict<'v>> {
+        if false { println!("Ignore unused this var. _this isn't allowed by starlark. {:?}", this); }
+        get_os_impl::get_os(starlark_heap)
+    }
     fn dll_inject(this: SysLibrary, dll_path: String, pid: u32) -> anyhow::Result<NoneType> {
         if false { println!("Ignore unused this var. _this isn't allowed by starlark. {:?}", this); }
         dll_inject_impl::dll_inject(dll_path, pid)

implants/lib/eldritch/src/sys/get_os_impl.rs

@@ -0,0 +1,58 @@
+use anyhow::Result;
+use starlark::collections::SmallMap;
+use starlark::const_frozen_string;
+use starlark::values::Heap;
+use starlark::values::dict::Dict;
+
+#[derive(Debug)]
+struct OsInfo {
+    arch:           String,
+    desktop_env:    String,
+    distro:         String,
+    platform:       String,
+}
+
+pub fn get_os(starlark_heap: &Heap) -> Result<Dict> {
+
+    let cmd_res = handle_get_os()?;
+
+    let res = SmallMap::new();
+    let mut dict_res = Dict::new(res);
+    let arch_value = starlark_heap.alloc_str(&cmd_res.arch);
+    dict_res.insert_hashed(const_frozen_string!("arch").to_value().get_hashed().unwrap(), arch_value.to_value());
+
+    let desktop_env_value = starlark_heap.alloc_str(&cmd_res.desktop_env);
+    dict_res.insert_hashed(const_frozen_string!("desktop_env").to_value().get_hashed().unwrap(), desktop_env_value.to_value());
+
+    let distro = starlark_heap.alloc_str(&cmd_res.distro);
+    dict_res.insert_hashed(const_frozen_string!("distro").to_value().get_hashed().unwrap(), distro.to_value());
+
+    let platform = starlark_heap.alloc_str(&cmd_res.platform);
+    dict_res.insert_hashed(const_frozen_string!("platform").to_value().get_hashed().unwrap(), platform.to_value());
+
+    Ok(dict_res)
+}
+
+fn handle_get_os() -> Result<OsInfo> {
+    return Ok(OsInfo { 
+        arch:           whoami::arch().to_string(),
+        desktop_env:    whoami::desktop_env().to_string(),
+        distro:         whoami::distro().to_string(),
+        platform:       whoami::platform().to_string(),
+    });
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_sys_get_os() -> anyhow::Result<()>{
+
+        let test_heap = Heap::new();
+        let res = get_os(&test_heap)?;
+        println!("{}", res.to_string());
+        assert!(res.to_string().contains(r#""arch": "x86_64""#));
+        Ok(())
+    }
+}