memory allocation basics

Author: Whitecat18

Basics/mem_allocation.rs

@@ -0,0 +1,98 @@
+/* 
+Malware Basics: Allocating at Windows Memory via Rust Functions and Windows API'S ! 
+
+For more codes: https://github.com/Whitecat18/Rust-for-Malware-Development.git
+By: @5mukx
+
+*/
+
+// MANUAL MEMORY ALLOCATION WITHOUT [winapi] aka WINDOWS API.
+
+/* 
+
+use std::alloc::{alloc, dealloc, Layout};
+use std::ptr;
+use std::ffi::CString;
+
+use std::ptr::copy_nonoverlapping;
+
+fn main(){
+    let size = 100;
+
+    let layout = Layout::from_size_align(size, std::mem::align_of::<u8>()).unwrap();
+    
+    // Allocate memory with global Allocator 
+    let p_addr = unsafe { alloc(layout)};
+
+    unsafe{
+        if p_addr.is_null(){
+            // filling the allocated memory with 0 .
+            ptr::write_bytes(p_addr, 0, size);
+            // Using CString, An C-compatible, nul-terminated string with no nul bytes in the middle.
+
+            let string = CString::new("Maldev hits diffrerent").expect("Error while creating cstring");
+            
+            // copy_nonoverlapping is semantically equivalent to C's memcpy but with the argument order swapped
+                copy_nonoverlapping(string.as_ptr(), p_addr as *mut i8, string.as_bytes().len());
+
+                let content = std::slice::from_raw_parts(p_addr, string.as_bytes().len());
+
+                println!("[+] Memory Content: {:?}",content);
+                
+                println!("[+] Deallocating Mem contnet");
+                dealloc(p_addr, layout);
+            } else {
+                println!("[-] Failed to allocate memory");
+            }
+        }
+}
+
+*/
+
+// MEMORY ALLOCATION USING [winapi]
+
+/*
+Make sure you have include these dependencies on Cargo.toml file !
+
+[dependencies]
+winapi = { version = "0.3", features = ["minwindef", "winbase"] }
+*/
+
+
+
+use winapi::um::heapapi::{GetProcessHeap, HeapAlloc, HeapFree};
+use std::slice::from_raw_parts;
+fn main(){
+    unsafe{
+        let heap = GetProcessHeap();
+        if heap.is_null(){
+            println!("[-] Failed to get process heap");
+            return
+        }
+        
+        // https://learn.microsoft.com/en-us/windows/win32/api/heapapi/nf-heapapi-heapalloc
+        // 0x00000008 -> /. similar to winnt::HEAP_ZERO_MEMORY; 
+        let p_address = HeapAlloc(heap, 0x00000008, 100);
+
+        if p_address.is_null(){
+            println!("[-] Failed to allocate memory on the heap");
+            return
+        }
+
+        println!("[+] Base Address of Allocated memory: {:#?}",p_address);
+
+        let string = "Maldev hits different".as_ptr() as *const u8;
+
+
+        std::ptr::copy_nonoverlapping(string , p_address as *mut u8, 100);
+
+        let content = from_raw_parts(p_address as *const u8, 100);
+        
+        println!("[+] Memory content: {:?}", content);
+
+        
+        HeapFree(heap, 0, p_address);
+
+        println!("[+] Freed Allocated memory !");
+    }
+}