From 8aa55bdb23f444523d0c89524d070a3d42f5e380 Mon Sep 17 00:00:00 2001
From: Garrett Dickinson <dickinsongarrett@gmail.com>
Date: Mon, 10 Apr 2023 22:24:44 -0500
Subject: [PATCH] More progress towards patch injection framework

---
 notes/todo.md               |   9 +++++++++
 src/patcher.rs              |  11 +++++------
 src/util.rs                 |   7 ++++++-
 testing/hello_patched       | Bin 15960 -> 15960 bytes
 testing/patches/hello.patch |  17 ++++++++++++++---
 testing/src/functions.c     |  12 ++++++++++++
 6 files changed, 46 insertions(+), 10 deletions(-)
 create mode 100644 notes/todo.md
 create mode 100644 testing/src/functions.c

diff --git a/notes/todo.md b/notes/todo.md
new file mode 100644
index 0000000..013aa18
--- /dev/null
+++ b/notes/todo.md
@@ -0,0 +1,9 @@
+To Do
+
+Code injection
+    - 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
+    - 
+
+Injected code: 0x680
+Call: 0x1160
\ No newline at end of file
diff --git a/src/patcher.rs b/src/patcher.rs
index 2b9aa42..dd30245 100644
--- a/src/patcher.rs
+++ b/src/patcher.rs
@@ -37,8 +37,7 @@ pub fn patch_binary(binary_contents: Vec<u8>, binary_name: String, patch_file_pa
 
     file.write_all(&bytes)
         .expect("[Error] Could not write to patched binary file");
-    
-    file.flush();
+
 }
 
 
@@ -57,11 +56,11 @@ fn parse_patch_file(patch_path: &String) -> HashMap<usize, Vec<u8>>{
         
         for line in contents {
             let unwrapped = line.unwrap();
-            if unwrapped.trim().starts_with("#") {
-
+            if unwrapped.trim().starts_with("#") || unwrapped.is_empty() {
+                //Skip
             } else {
                 let mut statement = unwrapped.split(":");
-                let address: usize = statement.next().unwrap().trim().parse::<usize>().unwrap();
+                let address: usize = util::hex_to_int(statement.next().unwrap().trim()).unwrap();
                 let data: &str = statement.next().unwrap().trim();
 
                 if !data.is_empty() {
@@ -85,7 +84,7 @@ fn parse_patch_file(patch_path: &String) -> HashMap<usize, Vec<u8>>{
                     } else {
                         // Data is comma seperated list or a single value
                         let byte_str: String = data.replace(",", "");
-                        let bytes: Vec<u8> = util::decode_hex(&byte_str).unwrap();
+                        let bytes: Vec<u8> = util::hex_to_buff(&byte_str).unwrap();
                         
                         print!("{}: ", address);
                     
diff --git a/src/util.rs b/src/util.rs
index 93fb05f..cf47695 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -348,9 +348,14 @@ pub fn read_lines(filename: String) -> io::Lines<BufReader<File>> {
 
 // Borrowed from the following Stack Overflow post
 // https://stackoverflow.com/questions/52987181/how-can-i-convert-a-hex-string-to-a-u8-slice
-pub fn decode_hex(s: &str) -> Result<Vec<u8>, ParseIntError> {
+pub fn hex_to_buff(s: &str) -> Result<Vec<u8>, ParseIntError> {
     (0..s.len())
         .step_by(2)
         .map(|i| u8::from_str_radix(&s[i..i + 2], 16))
         .collect()
+}
+
+
+pub fn hex_to_int(s: &str) -> Result<usize, ParseIntError> {
+    return usize::from_str_radix(s, 16)
 }
\ No newline at end of file
diff --git a/testing/hello_patched b/testing/hello_patched
index 7cf478a79d2899ea750f2d1198e600eb0c70e0cd..899b49d7cb1d3ad235d0ed823468cca1da7dfe9e 100755
GIT binary patch
delta 78
zcmcanbE9U%1VLMm;|CZS7#KW`ABRxK4hVvHhj@X48QDPgVITtuc%<g!<m)Je=NILq
PC~j^PH0Il+5FrNutlkws

delta 20
ccmcanbE9U%1i{S@1Qqxu8?XgzQizZP0B4j4EdT%j

diff --git a/testing/patches/hello.patch b/testing/patches/hello.patch
index 04a869b..9334b7d 100644
--- a/testing/patches/hello.patch
+++ b/testing/patches/hello.patch
@@ -1,3 +1,14 @@
-8196  :  "Hello, Patch!"
-#20041 : DE,AD,BE,EF
-#45620 : 00,01,02,03
\ No newline at end of file
+# 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!"
\ No newline at end of file
diff --git a/testing/src/functions.c b/testing/src/functions.c
new file mode 100644
index 0000000..ecd0424
--- /dev/null
+++ b/testing/src/functions.c
@@ -0,0 +1,12 @@
+int main() {
+    
+    return 0;
+}
+
+int my_function() {
+    return 0;
+}
+
+int another_function() {
+    return 0;
+}
\ No newline at end of file