Add support for ELF code injection

notes/code_injection.md

@@ -0,0 +1,6 @@
+# ELF Code injection notes
+
+- Locate PT_NOTE segments in binary
+- Locate a suitable `.note.*` section for replacing code
+- Modify the injection code section type from `SHT_NOTE` to `SHT_PROGBITS`
+- Update relevant start, offset, and end addresses for new section

notes/todo.md

@@ -1,9 +1,9 @@
-To Do
+# To Do
 
-Code injection
+## Code injection
-    - Have a script with 3 functions, (main, funcA, funcB), and replace refs to funcA with funcB
+- Have a script with 3 functions, (main, funcA, funcB), and replace refs to funcA with funcB
-    - Trampoline definitions of a function to a new modified function that gets places in memory
+- Trampoline definitions of a function to a new modified function that gets places in memory
-    - 
 
 Injected code: 0x680
+
 Call: 0x1160

src/elf.rs

@@ -121,8 +121,9 @@ pub struct FileHeader {
 }
 
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct ProgramHeader {
+    pub id: u16,
     pub program_type: u32,
     pub flags: u32,
     pub offset: u64,
@@ -134,9 +135,10 @@ pub struct ProgramHeader {
 }
 
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct SectionHeader {
-    pub name: u32,
+    pub id: u16,
+    pub name_idx: u32,
     pub section_type: u32,
     pub flags: u64,
     pub addr: u64,

src/main.rs

@@ -20,7 +20,7 @@ mod patcher;
 fn main() {
     // Collect our execution args
     let args: Vec<String> = env::args().collect();
-    let mut patch_mode: bool = false;
+    let mut inject_mode: bool = false;
     let mut patch_file_path: &String = &"".to_string();
 
     // Grab our filepath from our options
@@ -34,7 +34,7 @@ fn main() {
     if &args.len() > &2 {
         if &args[2] == "-p" {
             if &args.len() >= &4 {
-                patch_mode = true;
+                inject_mode = true;
                 patch_file_path = &args[3];
             } else {
                 util::print_help();
@@ -87,6 +87,7 @@ fn main() {
                 let shstrtab_section: elf::SectionHeader = util::build_section_header(
                     bytes,
                     shstrtab_offset as usize,
+                    file_header.shstrndx,
                     file_header.is_x86_64
                 );
 
@@ -104,17 +105,18 @@ fn main() {
                 let mut section_table_count: i32 = 0;
 
                 // Iterate through number of section headers
-                for _ in 0..file_header.shnum {
+                for i in 0..file_header.shnum {
 
                     // Build section header data structure
                     let section_header: elf::SectionHeader = util::build_section_header(
                         bytes, 
                         section_table_offset as usize,
+                        i,
                         file_header.is_x86_64
                     );
 
                     // Determine the section name for each section using the shstrtab data
-                    let section_name: String = util::parse_section_name(&shstrtab_data, section_header.name as usize);
+                    let section_name: String = util::parse_section_name(&shstrtab_data, section_header.name_idx as usize);
 
                     util::pp_section_header(&section_header, section_table_count, &section_name);
 
@@ -131,19 +133,25 @@ fn main() {
 
                 let mut program_table_offset = file_header.phoff;
                 let mut program_table_count: i32 = 0;
+                let mut pt_note_offset: usize = 0;
 
                 // Iterate through number of Program Headers
-                for _ in 0..file_header.phnum {
+                for i in 0..file_header.phnum {
                     // Build Program Header data structure
                     let program_header: elf::ProgramHeader = util::build_program_header(
                         bytes, 
                         program_table_offset as usize,
+                        i,
                         file_header.is_x86_64
                     );
 
                     // Parse the program name using the program type
                     let program_name: String = util::parse_program_segment_type(program_header.program_type);
 
+                    if (program_name == "PT_NOTE") && (pt_note_offset == 0) {
+                        pt_note_offset = program_table_offset as usize;
+                    }
+
                     util::pp_program_header(&program_header, program_table_count, &program_name);
 
                     // Update the program header table offset counter based on the program header size
@@ -151,6 +159,13 @@ fn main() {
                     program_table_count += 1;
                 }
 
+                let note_segment: elf::ProgramHeader = util::build_program_header(
+                    bytes, 
+                    pt_note_offset,
+                    0,
+                    file_header.is_x86_64
+                );
+
 
                 // Now that we have all the sections, spit out the .text section and start a linear disassembly
                 let text_section: &elf::SectionHeader = section_table_map.get(".text").unwrap();
@@ -221,14 +236,17 @@ fn main() {
                 }
 
 
-                if patch_mode {
+                if inject_mode {
 
-                    println!("\n==== Applying Patch To Binary ====\n");
+                    println!("\n==== Injecting Payload To Binary ====\n");
 
                     patcher::patch_binary(
                         bytes.to_vec(),
                         file_path.to_string(),
-                        &patch_file_path
+                        &patch_file_path,
+                        &file_header,
+                        section_table_map,
+                        note_segment
                     );
                 }
 
@@ -238,7 +256,7 @@ fn main() {
             }
         }
     } else {
-        println!("[Error] '{}' does not exist", file_path);
+        println!("[Error] File '{}' does not exist", file_path);
         exit(-1);
     }
 

src/patcher.rs

@@ -4,105 +4,124 @@
 // Description: Houses binary rewriting and patching functionality for chisel.
 
 use std::path;
+use std::fs;
 use std::collections::HashMap;
 use std::io::Write;
+use std::io::Error;
 
 use crate::util;
+use crate::elf;
 
 
-pub fn patch_binary(binary_contents: Vec<u8>, binary_name: String, patch_file_path: &String) {
+pub fn patch_binary(
+    binary_contents: Vec<u8>,
+    binary_name: String,
+    patch_file_path: &String,
+    file_header: &elf::FileHeader,
+    section_header_map: HashMap<String, elf::SectionHeader>,
+    note_segment: elf::ProgramHeader) {
     
-    let patch_data: HashMap<usize, Vec<u8>> = parse_patch_file(patch_file_path);
-    let mut bytes: Vec<u8> = binary_contents;
 
-    println!("Patch data read successfully, applying...");
+    let patch_result: Result<Vec<u8>,Error> = read_patch_file(patch_file_path);
+    let patch_data: &Vec<u8> = &patch_result.as_ref().unwrap();
+    
+    let mut program_data: Vec<u8> = binary_contents;
 
-    for patch in patch_data {
-        let start_offset = patch.0;
-        let mut i: usize = 0;
-        while i < (patch.1.len()) {
-            bytes[(start_offset + i) as usize] = patch.1[i];
-            i += 1;
-        }
-    }
 
-    println!("Done!");
+    // Apply patch to end of binary
+    println!("Patch data read successfully, injecting at end of binary...");
 
-    let patched_file_name: String = binary_name + "_patched";
+    let injection_offset: usize = program_data.len();
+    let injection_size: usize = patch_data.len();
+    let injection_addr: usize = injection_offset;
 
-    println!("Writing '{}' to disk...", patched_file_name);
+    program_data.extend_from_slice(patch_data);
 
-    let mut file = std::fs::File::create(patched_file_name)
+    print!("Done!");
+
+
+    // Locate a note segment
+    println!("Pulling .note.ABI-tag segment data...");
+    let note_section: &elf::SectionHeader = section_header_map.get(".note.ABI-tag")
+        .expect("[Error] Failed to pull ABI-tag section from binary!");
+    print!("Done!\n");
+    
+    println!("Note section address: {:#04x}", note_section.addr);
+    println!("Note section offset: {:#04x}", note_section.offset);
+    println!("Note section size: {}", note_section.size);
+    println!("");
+    println!("Injected address: {:#04x}", injection_addr);
+    println!("Injected section offset: {:#04x}", injection_offset);
+    println!("Injected section size: {}", injection_size);
+
+
+    // Rewrite the section header
+    let mut injected_section: elf::SectionHeader = elf::SectionHeader::from(note_section.clone());
+
+    injected_section.section_type = 1;
+    injected_section.addr = injection_addr as u64;
+    injected_section.offset = injection_offset as u64;
+    injected_section.size = injection_size as u64;
+    
+    util::overwrite_section_header(
+        &mut program_data,
+        file_header.shoff as usize,
+        file_header.shentsize as usize,
+        injected_section.id as usize,
+        &injected_section,
+        file_header.is_x86_64
+    );
+
+
+    // 
+    // Rewrite the section header
+    let mut injected_segment: elf::ProgramHeader = elf::ProgramHeader::from(note_segment.clone());
+
+    injected_segment.program_type = 1;
+    injected_segment.offset = injection_offset as u64;
+    injected_segment.vaddr = injection_offset as u64;
+    injected_segment.paddr = injection_offset as u64;
+    injected_segment.filesz = injection_size as u64;
+    injected_segment.memsz = injection_size as u64;
+    injected_segment.flags = 5;
+    injected_segment.align = 0x1000;
+
+    util::overwrite_segment_header(
+        &mut program_data,
+        file_header.shoff as usize,
+        file_header.shentsize as usize,
+        injected_section.id as usize,
+        &injected_section,
+        file_header.is_x86_64
+    );
+
+
+
+
+    util::overwrite_entrypoint(&mut program_data, injection_offset);
+
+
+    // Spit everything back out
+    let out_file_name: String = binary_name + ".patched";
+
+    println!("Writing '{}' to disk...", out_file_name);
+
+    let mut file = std::fs::File::create(out_file_name)
         .expect("[Error] Could not write patched binary to disk");
 
-    file.write_all(&bytes)
+    file.write_all(&program_data)
-        .expect("[Error] Could not write to patched binary file");
+        .expect("[Error] Could not write to patched binary data file");
-
 }
 
 
-fn parse_patch_file(patch_path: &String) -> HashMap<usize, Vec<u8>>{
+fn read_patch_file(patch_path: &String) -> Result<Vec<u8>, std::io::Error> {
-    // Load the file from patch_binary() arg
-    // Iterate through file, if line starts with # ignore
-    // Otherwise, parse as such
-    //      [ADDRESS] [SPACE] [HEX],[HEX],[HEX],....
-    //      [ADDRESS] [SPACE] [STRING]
 
-    if path::Path::new(patch_path).exists() && patch_path.ends_with(".patch") {
+    if path::Path::new(patch_path).exists() && patch_path.ends_with(".bin") {
         println!("Patch file exists, reading '{}'...", patch_path);
         
-        let contents = util::read_lines(patch_path.to_string());
+        let contents: Result<Vec<u8>, std::io::Error> = fs::read(patch_path);
-        let mut patch_data: HashMap<usize, Vec<u8>> = HashMap::new();
         
-        for line in contents {
+        return contents;
-            let unwrapped = line.unwrap();
-            if unwrapped.trim().starts_with("#") || unwrapped.is_empty() {
-                //Skip
-            } else {
-                let mut statement = unwrapped.split(":");
-                let address: usize = util::hex_to_int(statement.next().unwrap().trim()).unwrap();
-                let data: &str = statement.next().unwrap().trim();
-
-                if !data.is_empty() {
-                    if data.contains("\"") {
-                        // Value is a string literal
-                        let cleaned = data.replace("\"", "");
-                        let bytes: Vec<u8> = cleaned.as_bytes().to_vec();
-                        
-                        print!("{}: ", address);
-                    
-                        let mut i = 0;
-                        while i < bytes.len() {
-                            print!("{} ", bytes[i]);
-                            i = i + 1;
-                        }
-
-                        println!();
-
-                        patch_data.insert(address, bytes);
-                        
-                    } else {
-                        // Data is comma seperated list or a single value
-                        let byte_str: String = data.replace(",", "");
-                        let bytes: Vec<u8> = util::hex_to_buff(&byte_str).unwrap();
-                        
-                        print!("{}: ", address);
-                    
-                        let mut i = 0;
-                        while i < bytes.len() {
-                            print!("{} ", bytes[i]);
-                            i = i + 1;
-                        }
-
-                        println!();
-
-                        patch_data.insert(address, bytes);
-                    }
-                }
-            }
-        }
-
-        return patch_data;
 
     } else {
         println!("[Error] Patch file '{}' is invalid or cannot be read, exiting...", patch_path);

src/patcher.rs.bak

@@ -0,0 +1,111 @@
+// patcher.rs
+// Author: Garrett Dickinson
+// Created: 04/06/2023
+// Description: Houses binary rewriting and patching functionality for chisel.
+
+use std::path;
+use std::collections::HashMap;
+use std::io::Write;
+
+use crate::util;
+
+
+pub fn patch_binary(binary_contents: Vec<u8>, binary_name: String, patch_file_path: &String) {
+    
+    let patch_data: HashMap<usize, Vec<u8>> = parse_patch_file(patch_file_path);
+    let mut bytes: Vec<u8> = binary_contents;
+
+    println!("Patch data read successfully, applying...");
+
+    for patch in patch_data {
+        let start_offset = patch.0;
+        let mut i: usize = 0;
+        while i < (patch.1.len()) {
+            bytes[(start_offset + i) as usize] = patch.1[i];
+            i += 1;
+        }
+    }
+
+    println!("Done!");
+
+    let patched_file_name: String = binary_name + "_patched";
+
+    println!("Writing '{}' to disk...", patched_file_name);
+
+    let mut file = std::fs::File::create(patched_file_name)
+        .expect("[Error] Could not write patched binary to disk");
+
+    file.write_all(&bytes)
+        .expect("[Error] Could not write to patched binary file");
+
+}
+
+
+fn parse_patch_file(patch_path: &String) -> HashMap<usize, Vec<u8>>{
+    // Load the file from patch_binary() arg
+    // Iterate through file, if line starts with # ignore
+    // Otherwise, parse as such
+    //      [ADDRESS] [SPACE] [HEX],[HEX],[HEX],....
+    //      [ADDRESS] [SPACE] [STRING]
+
+    if path::Path::new(patch_path).exists() && patch_path.ends_with(".patch") {
+        println!("Patch file exists, reading '{}'...", patch_path);
+        
+        let contents = util::read_lines(patch_path.to_string());
+        let mut patch_data: HashMap<usize, Vec<u8>> = HashMap::new();
+        
+        for line in contents {
+            let unwrapped = line.unwrap();
+            if unwrapped.trim().starts_with("#") || unwrapped.is_empty() {
+                //Skip
+            } else {
+                let mut statement = unwrapped.split(":");
+                let address: usize = util::hex_to_int(statement.next().unwrap().trim()).unwrap();
+                let data: &str = statement.next().unwrap().trim();
+
+                if !data.is_empty() {
+                    if data.contains("\"") {
+                        // Value is a string literal
+                        let cleaned = data.replace("\"", "");
+                        let bytes: Vec<u8> = cleaned.as_bytes().to_vec();
+                        
+                        print!("{}: ", address);
+                    
+                        let mut i = 0;
+                        while i < bytes.len() {
+                            print!("{} ", bytes[i]);
+                            i = i + 1;
+                        }
+
+                        println!();
+
+                        patch_data.insert(address, bytes);
+                        
+                    } else {
+                        // Data is comma seperated list or a single value
+                        let byte_str: String = data.replace(",", "");
+                        let bytes: Vec<u8> = util::hex_to_buff(&byte_str).unwrap();
+                        
+                        print!("{}: ", address);
+                    
+                        let mut i = 0;
+                        while i < bytes.len() {
+                            print!("{} ", bytes[i]);
+                            i = i + 1;
+                        }
+
+                        println!();
+
+                        patch_data.insert(address, bytes);
+                    }
+                }
+            }
+        }
+
+        return patch_data;
+
+    } else {
+        println!("[Error] Patch file '{}' is invalid or cannot be read, exiting...", patch_path);
+        std::process::exit(0);    
+    }
+}

src/util.rs

@@ -5,9 +5,9 @@
 //              functions.
 
 use std::mem;
-use std::io::{self, BufReader, BufRead};
+// use std::io::{self, BufReader, BufRead};
-use std::fs::File;
+// use std::fs::File;
-use std::num::ParseIntError;
+// use std::num::ParseIntError;
 
 use crate::elf::{self, EndianType, ArchitectureType};
 
@@ -43,7 +43,7 @@ pub fn build_file_header(data: &Vec<u8>) -> elf::FileHeader {
 }
 
 
-pub fn build_program_header(data: &Vec<u8>, phoffset: usize, is_x86_64: bool) -> elf::ProgramHeader {
+pub fn build_program_header(data: &Vec<u8>, phoffset: usize, id: u16, is_x86_64: bool) -> elf::ProgramHeader {
 
     // Cast the supplied is_x86_64 bool to an array offset
     // 0 : x86
@@ -51,6 +51,7 @@ pub fn build_program_header(data: &Vec<u8>, phoffset: usize, is_x86_64: bool) ->
     let arch: usize = is_x86_64.into();
 
     let program_header: elf::ProgramHeader = elf::ProgramHeader {
+        id: id,
         program_type: u32_from_buffer(data, phoffset + elf::PH_TYPE_OFFSET as usize),
         flags: u32_from_buffer(data, phoffset + elf::PH_FLAGS_OFFSET[arch] as usize),
         offset: u64_from_buffer(data, phoffset + elf::PH_OFFSET_OFFSET[arch] as usize),
@@ -65,7 +66,48 @@ pub fn build_program_header(data: &Vec<u8>, phoffset: usize, is_x86_64: bool) ->
 }
 
 
-pub fn build_section_header(data: &Vec<u8>, shoffset: usize, is_x86_64: bool) -> elf::SectionHeader {
+pub fn overwrite_segment_header(program_data: &mut Vec<u8>,
+    stoffset: usize,
+    shentsize: usize,
+    shentidx: usize,
+    new_section: &elf::SectionHeader,
+    is_x86_64: bool) {
+
+// Cast the supplied is_x86_64 bool to an array offset
+// 0 : x86
+// 1 : x64
+let arch: usize = is_x86_64.into();
+
+println!("stoffset {}", stoffset);
+println!("shentsize {}", shentsize);
+println!("shentidx {}", shentidx);
+
+let section_addr_offset: usize = stoffset + (shentsize * shentidx) + elf::SH_ADDR_OFFSET[arch] as usize;
+let section_offset_offset: usize = stoffset + (shentsize * shentidx) + elf::SH_OFFSET_OFFSET[arch] as usize;
+let section_size_offset: usize = stoffset + (shentsize * shentidx) + elf::SH_SIZE_OFFSET[arch] as usize;
+let section_type_offset: usize = stoffset + (shentsize * shentidx) + elf::SH_TYPE_OFFSET as usize;
+
+program_data[section_addr_offset..section_addr_offset+8].copy_from_slice(
+&new_section.addr.to_ne_bytes().to_vec());
+println!("Overwriting section addr with {:#04x}", new_section.addr);
+
+program_data[section_offset_offset..section_offset_offset+8].copy_from_slice(
+&new_section.offset.to_ne_bytes().to_vec());
+println!("Overwriting section offset with {:#04x}", new_section.offset as usize);
+
+program_data[section_size_offset..section_size_offset+8].copy_from_slice(
+&new_section.size.to_ne_bytes().to_vec());
+println!("Overwriting section size with {:#04x}", new_section.size as usize);
+
+program_data[section_type_offset..section_type_offset+4].copy_from_slice(
+&new_section.section_type.to_ne_bytes().to_vec());
+println!("Overwriting section type with {:#04x}", new_section.section_type as usize);
+
+// return section_header;
+}
+
+
+pub fn build_section_header(data: &Vec<u8>, stoffset: usize, id: u16, is_x86_64: bool) -> elf::SectionHeader {
 
     // Cast the supplied is_x86_64 bool to an array offset
     // 0 : x86
@@ -73,22 +115,74 @@ pub fn build_section_header(data: &Vec<u8>, shoffset: usize, is_x86_64: bool) ->
     let arch: usize = is_x86_64.into();
 
     let section_header: elf::SectionHeader = elf::SectionHeader {
-        name: u32_from_buffer(data, shoffset + elf::SH_NAME_OFFSET as usize),
+        id: id,
-        section_type: u32_from_buffer(data, shoffset + elf::SH_TYPE_OFFSET as usize),
+        name_idx: u32_from_buffer(data, stoffset + elf::SH_NAME_OFFSET as usize),
-        flags: u64_from_buffer(data, shoffset + elf::SH_FLAGS_OFFSET as usize),
+        section_type: u32_from_buffer(data, stoffset + elf::SH_TYPE_OFFSET as usize),
-        addr: u64_from_buffer(data, shoffset + elf::SH_ADDR_OFFSET[arch] as usize),
+        flags: u64_from_buffer(data, stoffset + elf::SH_FLAGS_OFFSET as usize),
-        offset: u64_from_buffer(data, shoffset + elf::SH_OFFSET_OFFSET[arch] as usize),
+        addr: u64_from_buffer(data, stoffset + elf::SH_ADDR_OFFSET[arch] as usize),
-        size: u64_from_buffer(data, shoffset + elf::SH_SIZE_OFFSET[arch] as usize),
+        offset: u64_from_buffer(data, stoffset + elf::SH_OFFSET_OFFSET[arch] as usize),
-        link: u32_from_buffer(data, shoffset + elf::SH_LINK_OFFSET[arch] as usize),
+        size: u64_from_buffer(data, stoffset + elf::SH_SIZE_OFFSET[arch] as usize),
-        info: u32_from_buffer(data, shoffset + elf::SH_INFO_OFFSET[arch] as usize),
+        link: u32_from_buffer(data, stoffset + elf::SH_LINK_OFFSET[arch] as usize),
-        addralign: u64_from_buffer(data, shoffset + elf::SH_ADDRALIGN_OFFSET[arch] as usize),
+        info: u32_from_buffer(data, stoffset + elf::SH_INFO_OFFSET[arch] as usize),
-        entsize: u64_from_buffer(data, shoffset + elf::SH_ENTSIZE_OFFSET[arch] as usize)
+        addralign: u64_from_buffer(data, stoffset + elf::SH_ADDRALIGN_OFFSET[arch] as usize),
+        entsize: u64_from_buffer(data, stoffset + elf::SH_ENTSIZE_OFFSET[arch] as usize)
     };
 
     return section_header;
 }
 
 
+pub fn overwrite_section_header(program_data: &mut Vec<u8>,
+                                stoffset: usize,
+                                shentsize: usize,
+                                shentidx: usize,
+                                new_section: &elf::SectionHeader,
+                                is_x86_64: bool) {
+
+    // Cast the supplied is_x86_64 bool to an array offset
+    // 0 : x86
+    // 1 : x64
+    let arch: usize = is_x86_64.into();
+
+    println!("stoffset {}", stoffset);
+    println!("shentsize {}", shentsize);
+    println!("shentidx {}", shentidx);
+
+    let section_addr_offset: usize = stoffset + (shentsize * shentidx) + elf::SH_ADDR_OFFSET[arch] as usize;
+    let section_offset_offset: usize = stoffset + (shentsize * shentidx) + elf::SH_OFFSET_OFFSET[arch] as usize;
+    let section_size_offset: usize = stoffset + (shentsize * shentidx) + elf::SH_SIZE_OFFSET[arch] as usize;
+    let section_type_offset: usize = stoffset + (shentsize * shentidx) + elf::SH_TYPE_OFFSET as usize;
+
+    program_data[section_addr_offset..section_addr_offset+8].copy_from_slice(
+                &new_section.addr.to_ne_bytes().to_vec());
+    println!("Overwriting section addr with {:#04x}", new_section.addr);
+
+    program_data[section_offset_offset..section_offset_offset+8].copy_from_slice(
+        &new_section.offset.to_ne_bytes().to_vec());
+    println!("Overwriting section offset with {:#04x}", new_section.offset as usize);
+
+    program_data[section_size_offset..section_size_offset+8].copy_from_slice(
+        &new_section.size.to_ne_bytes().to_vec());
+    println!("Overwriting section size with {:#04x}", new_section.size as usize);
+
+    program_data[section_type_offset..section_type_offset+4].copy_from_slice(
+        &new_section.section_type.to_ne_bytes().to_vec());
+    println!("Overwriting section type with {:#04x}", new_section.section_type as usize);
+
+    // return section_header;
+}
+
+
+pub fn overwrite_entrypoint(program_data: &mut Vec<u8>,
+                           new_entry_point: usize) {
+    
+    let offset: usize = elf::ENTRYPOINT_OFFSET as usize;
+    program_data[offset..offset+8].copy_from_slice(
+        &new_entry_point.to_ne_bytes().to_vec()
+    );
+}
+
+
 pub fn parse_endian(endian: u8) -> elf::EndianType {
     match endian {
         0x00 => return EndianType::Big,
@@ -339,23 +433,28 @@ pub fn print_help() {
 }
 
 
-pub fn read_lines(filename: String) -> io::Lines<BufReader<File>> {
+// pub fn read_lines(filename: String) -> io::Lines<BufReader<File>> {
-    // Open the file in read-only mode.
+//     // Open the file in read-only mode.
-    let file = File::open(filename).unwrap(); 
+//     let file = File::open(filename).unwrap(); 
-    // Read the file line by line, and return an iterator of the lines of the file.
+//     // Read the file line by line, and return an iterator of the lines of the file.
-    return io::BufReader::new(file).lines(); 
+//     return io::BufReader::new(file).lines(); 
-}
+// }
 
-// Borrowed from the following Stack Overflow post
+// // Borrowed from the following Stack Overflow post
-// https://stackoverflow.com/questions/52987181/how-can-i-convert-a-hex-string-to-a-u8-slice
+// // https://stackoverflow.com/questions/52987181/how-can-i-convert-a-hex-string-to-a-u8-slice
-pub fn hex_to_buff(s: &str) -> Result<Vec<u8>, ParseIntError> {
+// pub fn hex_to_buff(s: &str) -> Result<Vec<u8>, ParseIntError> {
-    (0..s.len())
+//     (0..s.len())
-        .step_by(2)
+//         .step_by(2)
-        .map(|i| u8::from_str_radix(&s[i..i + 2], 16))
+//         .map(|i| u8::from_str_radix(&s[i..i + 2], 16))
-        .collect()
+//         .collect()
-}
+// }
 
 
-pub fn hex_to_int(s: &str) -> Result<usize, ParseIntError> {
+// pub fn hex_to_usize(s: &str) -> Result<usize, ParseIntError> {
-    return usize::from_str_radix(s, 16)
+//     return usize::from_str_radix(s, 16)
-}
+// }
+
+
+// pub fn usize_to_hex(i: usize) -> String {
+//     return format!("{:X}", i).to_string();
+// }

testing/elfpatching/hello_patch.s

@@ -0,0 +1,32 @@
+BITS 64
+
+SECTION .text
+global main
+
+main: 
+	push rax
+	push rcx
+	push rdx
+	push rsi
+	push rdi
+	push r11
+
+	mov rax,1
+	mov rdi,1
+	lea rsi,[rel $+hello-$]
+	mov rdx,[rel $+len-$]
+	syscall
+
+	pop r11
+	pop rdi
+	pop rsi
+	pop rdx
+	pop rcx
+	pop rax
+
+	;push 0x1060	; jump to original entry point
+	;				; could be replaced dynamically?
+	;ret
+
+hello: db "Calling injected code >:)",10
+len: dd 26

testing/patches/hello.patch

@@ -1,14 +0,0 @@
-# Trampoline segment
-# Pushes and returns to 0x116b
-#3f80 : 48C7C00100000048C7C70100000048C7C68007000048C7C20D0000000F05686B110000C3
-# No syscall
-1190 : 48C7C00100000048C7C70100000048C7C6C011000048C7C20D000000686B110000C3
-
-# String data to print from trampoline instruction
-11C0 : "Hello, World!"
-
-# Initial jump to trampoline
-#1160 : 6880060000C3
-#1160 :  6890110000C3
-
-2004 : "Hello, Patch!"

testing/src/functions.c

@@ -1,12 +0,0 @@
-int main() {
-    
-    return 0;
-}
-
-int my_function() {
-    return 0;
-}
-
-int another_function() {
-    return 0;
-}

testing/src/hello.s

@@ -1,46 +0,0 @@
-	.file	"main.c"
-	.text
-	.section	.rodata
-.LC0:
-	.string	"Hello, World!"
-	.text
-	.globl	main
-	.type	main, @function
-main:
-.LFB0:
-	.cfi_startproc
-	endbr64
-	pushq	%rbp
-	.cfi_def_cfa_offset 16
-	.cfi_offset 6, -16
-	movq	%rsp, %rbp
-	.cfi_def_cfa_register 6
-	leaq	.LC0(%rip), %rax
-	movq	%rax, %rdi
-	movl	$0, %eax
-	call	printf@PLT
-	movl	$0, %eax
-	popq	%rbp
-	.cfi_def_cfa 7, 8
-	ret
-	.cfi_endproc
-.LFE0:
-	.size	main, .-main
-	.ident	"GCC: (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0"
-	.section	.note.GNU-stack,"",@progbits
-	.section	.note.gnu.property,"a"
-	.align 8
-	.long	1f - 0f
-	.long	4f - 1f
-	.long	5
-0:
-	.string	"GNU"
-1:
-	.align 8
-	.long	0xc0000002
-	.long	3f - 2f
-2:
-	.long	0x3
-3:
-	.align 8
-4: