add assembly code tutorial

Author: x4nth055

README.md

@@ -81,6 +81,7 @@ This is a repository of all the tutorials of [The Python Code](https://www.thepy
 -[How to Get the Size of Directories in Python](https://www.thepythoncode.com/article/get-directory-size-in-bytes-using-python). ([code](general/calculate-directory-size))
 -[How to Play and Record Audio in Python](https://www.thepythoncode.com/article/play-and-record-audio-sound-in-python). ([code](general/recording-and-playing-audio))
 -[How to Get Geographic Locations in Python](https://www.thepythoncode.com/article/get-geolocation-in-python). ([code](general/geolocation))
+-[How to Assembly, Disassembly and Emulate Machine Code using Python](https://www.thepythoncode.com/article/arm-x86-64-assembly-disassembly-and-emulation-in-python). ([code](general/assembly-code))
 
 
 -### [Web Scraping](https://www.thepythoncode.com/topic/web-scraping)

general/assembly-code/README.md

@@ -0,0 +1,3 @@
+# [How to Assembly, Disassembly and Emulate Machine Code using Python](https://www.thepythoncode.com/article/arm-x86-64-assembly-disassembly-and-emulation-in-python)
+To run this:
+-`pip3 install -r requirements.txt`

general/assembly-code/arm_assembly.py

@@ -0,0 +1,56 @@
+# We need to emulate ARM
+fromunicornimportUc, UC_ARCH_ARM, UC_MODE_ARM, UcError
+# for accessing the R0 and R1 registers
+fromunicorn.arm_constimportUC_ARM_REG_R0, UC_ARM_REG_R1
+# We need to assemble ARM code
+fromkeystoneimportKs, KS_ARCH_ARM, KS_MODE_ARM, KsError
+
+
+ARM_CODE="""
+// n is r0, we will pass it from python, ans is r1
+mov r1, 1 // ans = 1
+loop:
+cmp r0, 0 // while n >= 0:
+mulgt r1, r1, r0 // ans *= n
+subgt r0, r0, 1 // n = n - 1
+bgt loop // 
+ // answer is in r1
+"""
+
+print("Assembling the ARM code")
+try:
+# initialize the keystone object with the ARM architecture
+ks=Ks(KS_ARCH_ARM, KS_MODE_ARM)
+# Assemble the ARM code
+ARM_BYTECODE, _=ks.asm(ARM_CODE)
+# convert the array of integers into bytes
+ARM_BYTECODE=bytes(ARM_BYTECODE)
+print(f"Code successfully assembled (length = {len(ARM_BYTECODE)})")
+print("ARM bytecode:", ARM_BYTECODE)
+exceptKsErrorase:
+print("Keystone Error: %s"%e)
+exit(1)
+
+
+# memory address where emulation starts
+ADDRESS=0x1000000
+
+print("Emulating the ARM code")
+try:
+# Initialize emulator in ARM mode
+mu=Uc(UC_ARCH_ARM, UC_MODE_ARM)
+# map 2MB memory for this emulation
+mu.mem_map(ADDRESS, 2*1024*1024)
+# write machine code to be emulated to memory
+mu.mem_write(ADDRESS, ARM_BYTECODE)
+# Set the r0 register in the code, let's calculate factorial(5)
+mu.reg_write(UC_ARM_REG_R0, 5)
+# emulate code in infinite time and unlimited instructions
+mu.emu_start(ADDRESS, ADDRESS+len(ARM_BYTECODE))
+# now print out the R0 register
+print("Emulation done. Below is the result")
+# retrieve the result from the R1 register
+r1=mu.reg_read(UC_ARM_REG_R1)
+print(">> R1 = %u"%r1)
+exceptUcErrorase:
+print("Unicorn Error: %s"%e)

general/assembly-code/disassemble_x86-64.py

@@ -0,0 +1,39 @@
+# We need to emulate ARM and x86 code
+fromunicornimportUc, UC_ARCH_X86, UC_MODE_64, UcError
+# for accessing the RAX and RDI registers
+fromunicorn.x86_constimportUC_X86_REG_RDI, UC_X86_REG_RAX
+# We need to disassemble x86_64 code
+fromcapstoneimportCs, CS_ARCH_X86, CS_MODE_64, CsError
+
+
+X86_MACHINE_CODE=b"\x48\x31\xc0\x48\xff\xc0\x48\x85\xff\x0f\x84\x0d\x00\x00\x00\x48\x99\x48\xf7\xe7\x48\xff\xcf\xe9\xea\xff\xff\xff"
+
+# memory address where emulation starts
+ADDRESS=0x1000000
+
+try:
+# Initialize the disassembler in x86 mode
+md=Cs(CS_ARCH_X86, CS_MODE_64)
+# iterate over each instruction and print it
+forinstructioninmd.disasm(X86_MACHINE_CODE, 0x1000):
+print("0x%x:\t%s\t%s"% (instruction.address, instruction.mnemonic, instruction.op_str))
+exceptCsErrorase:
+print("Capstone Error: %s"%e)
+
+try:
+# Initialize emulator in x86_64 mode
+mu=Uc(UC_ARCH_X86, UC_MODE_64)
+# map 2MB memory for this emulation
+mu.mem_map(ADDRESS, 2*1024*1024)
+# write machine code to be emulated to memory
+mu.mem_write(ADDRESS, X86_MACHINE_CODE)
+# Set the r0 register in the code to the number of 7
+mu.reg_write(UC_X86_REG_RDI, 7)
+# emulate code in infinite time & unlimited instructions
+mu.emu_start(ADDRESS, ADDRESS+len(X86_MACHINE_CODE))
+# now print out the R0 register
+print("Emulation done. Below is the result")
+rax=mu.reg_read(UC_X86_REG_RAX)
+print(">>> RAX = %u"%rax)
+exceptUcErrorase:
+print("Unicorn Error: %s"%e)

general/assembly-code/requirements.txt

@@ -0,0 +1,3 @@
+keystone-engine
+capstone
+unicorn