Help for boredom in covid19 times. Enjoy !

README.md

@@ -1,30 +1,35 @@
 # oppo_decrypt
-Oppo/Oneplus .ops Firmware decrypter
+Oppo .ops Firmware decrypter
 ------------------------------------
-
-Tested with "MSMDownloadTool V4.0" for Oneplus 5/6, Frida >10.4 and Windoze
+Works for oppo only, not oneplus !
 
 * backdoor.py : Enables hidden "readback" functionality
-* ops_decrypt.py  : Decrypts any part of the firmware with .ops extension, needs "MsmDownload Tool" and frida
+* ops_extract.py  : Decrypts any part of the firmware with .ops extension
 * ofp_decrypt.py  : Decrypts any part of the firmware with .ofp extension
 
 
-Based on Frida.re and python 3.6
+Based on python 3.x
 
 Installation:
 -------------
-'pip install frida'
+pip3 install pycrypto
+
 
-Windows only, sorry folks !
+Both Linux and Windows now, folks !
 
 Usage:
 -------- 
-* Oneplus 5 QD-Loader decryption:
-'python decrypt.py "MsmDownloadTool V4.0.exe" 0 0x92880'
+* Enable readback mode (use admin command prompt under windoze):
+```
+python3 backdoor.py "MsmDownloadTool V4.0.exe"'
+```
+
+* Extract ops file:
 
-* Enable readback mode:
-'python backdoor.py "MsmDownloadTool V4.0.exe"'
+```
+python3 ops_extract.py [myops.ops]
+```
 
 License:
 -------- 
-Share, modify and use as you like, but refer the original author !
+Share, modify and use as you like, but refer the original author !

ops_extract.py

@@ -0,0 +1,252 @@
+#!/usr/bin/env python3
+# (c) B.Kerler, MIT license
+import os
+import sys
+import xml.etree.ElementTree as ET
+from struct import unpack
+from binascii import unhexlify, hexlify
+from Crypto.Cipher import AES
+from Crypto.Hash import MD5
+import hashlib
+import shutil
+
+def swap(ch):
+    return ((ch & 0xF) << 4) + ((ch & 0xF0) >> 4)
+
+
+def keyshuffle(key, hkey):
+    for i in range(0, 0x10, 4):
+        key[i] = swap((hkey[i] ^ key[i]))
+        key[i + 1] = swap(hkey[i + 1] ^ key[i + 1])
+        key[i + 2] = swap(hkey[i + 2] ^ key[i + 2])
+        key[i + 3] = swap(hkey[i + 3] ^ key[i + 3])
+    return key
+
+def ROR(x, n, bits = 32):
+    mask = (2**n) - 1
+    mask_bits = x & mask
+    return (x >> n) | (mask_bits << (bits - n))
+
+def ROL(x, n, bits = 32):
+    return ROR(x, bits - n, bits)
+
+def generatekey1():
+    key1 = "42F2D5399137E2B2813CD8ECDF2F4D72"
+    key2 = "F6C50203515A2CE7D8C3E1F938B7E94C"
+    key3 = "67657963787565E837D226B69A495D21"
+
+    key1 = bytearray.fromhex(key1)
+    key2 = bytearray.fromhex(key2)
+    key3 = bytearray.fromhex(key3)
+
+    key2 = keyshuffle(key2, key3)
+    aeskey = bytes(hashlib.md5(key2).hexdigest()[0:16], 'utf-8')
+    key1 = keyshuffle(key1, key3)
+    iv = bytes(hashlib.md5(key1).hexdigest()[0:16], 'utf-8')
+    return aeskey,iv
+
+def generatekey2(filename):
+    keys = [
+                #R9s/A57t
+                ["V1.4.17/1.4.27",                          "27827963787265EF89D126B69A495A21","82C50203285A2CE7D8C3E198383CE94C","422DD5399181E223813CD8ECDF2E4D72"],
+                ["V1.5.13",                                 "67657963787565E837D226B69A495D21","F6C50203515A2CE7D8C3E1F938B7E94C","42F2D5399137E2B2813CD8ECDF2F4D72"],
+                #R15 Pro CPH1831 V1.6.6 / FindX CPH1871 V1.6.9 / R17 Pro CPH1877 V1.6.17 / R17 PBEM00 V1.6.17 / A5 2020 V1.7.6 / K3 CPH1955 V1.6.26 UFS
+                #Reno 5G CPH1921 V1.6.26 / Realme 3 Pro RMX1851 V1.6.17 / Reno 10X Zoom V1.6.26 / R17 CPH1879 V1.6.17 / R17 Neo CPH1893 / K1 PBCM30
+                ["V1.6.6/1.6.9/1.6.17/1.6.24/1.6.26/1.7.6", "3C2D518D9BF2E4279DC758CD535147C3","87C74A29709AC1BF2382276C4E8DF232","598D92E967265E9BCABE2469FE4A915E"],
+                #a3s
+                ["V1.6.17",                                 "E11AA7BB558A436A8375FD15DDD4651F","77DDF6A0696841F6B74782C097835169","A739742384A44E8BA45207AD5C3700EA"],
+                #RM1921EX V1.7.2, Realme X RMX1901 V1.7.2, Realme 5 Pro RMX1971 V1.7.2, Realme 5 RMX1911 V1.7.2
+                ["V1.7.2",                                  "8FB8FB261930260BE945B841AEFA9FD4","E529E82B28F5A2F8831D860AE39E425D","8A09DA60ED36F125D64709973372C1CF"]
+    ]
+
+    for dkey in keys:
+        key = bytearray()
+        iv = bytearray()
+        # "Read metadata failed"
+        mc = bytearray.fromhex(dkey[1])
+        userkey=bytearray.fromhex(dkey[2])
+        ivec=bytearray.fromhex(dkey[3])
+
+        #userkey=bytearray(unhexlify("A3D8D358E42F5A9E931DD3917D9A3218"))
+        #ivec=bytearray(unhexlify("386935399137416B67416BECF22F519A"))
+        #mc=bytearray(unhexlify("9E4F32639D21357D37D226B69A495D21"))
+
+        for i in range(0,len(userkey)):
+            v=ROL((userkey[i]^mc[i]),4,8)
+            key.append(v)
+
+        for i in range(0,len(userkey)):
+            v=ROL((ivec[i]^mc[i]),4,8)
+            iv.append(v)
+
+        h=MD5.new()
+        h.update(key)
+        key=h.digest()
+
+        h = MD5.new()
+        h.update(iv)
+        iv = h.digest()
+
+        key=hexlify(key).lower()[0:16]
+        iv=hexlify(iv).lower()[0:16]
+        pagesize,data=extract_xml(filename,key,iv)
+        if pagesize!=0:
+            return pagesize,key,iv,data
+    return 0,None,None,None
+
+
+def extract_xml(filename,key,iv):
+    filesize=os.stat(filename).st_size
+    with open(filename,'rb') as rf:
+        pagesize = 0x200
+        xmloffset=filesize-pagesize
+        rf.seek(xmloffset+0x10)
+        if unpack("<I",rf.read(4))[0]==0x7CEF:
+            pagesize=0x200
+        else:
+            pagesize=0x1000
+            xmloffset=filesize-pagesize
+            rf.seek(xmloffset + 0x10)
+            magic=unpack("<I", rf.read(4))[0]
+            if not magic == 0x7CEF:
+                print("Unknown pagesize. Aborting")
+                exit(0)
+
+        rf.seek(xmloffset+0x14)
+        offset=unpack("<I",rf.read(4))[0]*pagesize
+        length=unpack("<I",rf.read(4))[0]
+
+        rf.seek(offset)
+        data=rf.read(length)
+        dec=aes_cfb(data,key,iv)
+
+        #h=MD5.new()
+        #h.update(data)
+        #print(dec.decode('utf-8'))
+        #print(h.hexdigest())
+        #print("Done.")
+        if b"<?xml" in dec:
+            return pagesize,dec
+        else:
+            return 0,""
+
+def aes_cfb(data,key,iv):
+    ctx = AES.new(key, AES.MODE_CFB, iv=iv, segment_size=128)
+    decrypted = ctx.decrypt(data)
+    return decrypted
+
+def copysub(rf,wf,start,length):
+    rf.seek(start)
+    rlen=0
+    while (length > 0):
+        if length < 0x100000:
+            size = length
+        else:
+            size = 0x100000
+        data = rf.read(size)
+        wf.write(data)
+        rlen+=len(data)
+        length -= size
+    return rlen
+
+def decryptfile(key,iv,filename,path,wfilename,start,length,rlength,decryptsize=0x40000):
+    print(f"Extracting {wfilename}")
+    with open(filename, 'rb') as rf:
+        with open(os.path.join(path, wfilename), 'wb') as wf:
+            rf.seek(start)
+            if length>decryptsize:
+                size=decryptsize
+            else:
+                size=length
+            data=rf.read(size)
+            if size%4:
+                data+=(4-(size%4))*b'\x00'
+            outp = aes_cfb(data, key, iv)
+            if size==decryptsize:
+                wf.write(outp[:size])
+                rlength-=size
+                if rlength>0:
+                    copysub(rf,wf,start+decryptsize,rlength)
+            else:
+                wf.write(outp[:rlength])
+
+def main():
+    if len(sys.argv)<2:
+        print("Usage: ./ofp_libextract.py [Filename.ofp]")
+        exit(0)
+
+    filename=sys.argv[1]
+    filesize=os.stat(filename).st_size
+
+    #key,iv=generatekey1()
+    pagesize,key,iv,data=generatekey2(filename)
+    if pagesize==0:
+        print("Unknown key. Aborting")
+        exit(0)
+    else:
+        #print(data.decode('utf-8'))
+        xml=data[:data.rfind(b">")+1].decode('utf-8')
+
+    if "/" in filename:
+        path = filename[:filename.rfind("/")]
+    elif "\\" in filename:
+        path = filename[:filename.rfind("\\")]
+    else:
+        path = ""
+
+    path = os.path.join(path,"extract")
+
+    if os.path.exists(path):
+        shutil.rmtree(path)
+        os.mkdir(path)
+    else:
+        os.mkdir(path)
+
+    root = ET.fromstring(xml)
+    for child in root:
+        if child.tag == "Sahara":
+            for item in child:
+                if item.tag == "File":
+                    wfilename = item.attrib["Path"]
+                    start = int(item.attrib["FileOffsetInSrc"]) * pagesize
+                    length = int(item.attrib["SizeInSectorInSrc"]) * pagesize
+                    rlength = int(item.attrib["SizeInByteInSrc"])
+                    decryptfile(key, iv, filename, path, wfilename, start, length, rlength,rlength)
+        elif child.tag in ["Config","Provision","ChainedTableOfDigests","DigestsToSign"]:
+            for item in child:
+                if item.tag == "config":
+                    wfilename = item.attrib["filename"]
+                    start = int(item.attrib["SizeInSectorInSrc"]) * pagesize
+                    length = int(item.attrib["SizeInByteInSrc"])
+                    decryptfile(key,iv,filename, path, wfilename, start, length,length)
+        elif "Program" in child.tag:
+            # if not os.path.exists(os.path.join(path, child.tag)):
+            #    os.mkdir(os.path.join(path, child.tag))
+            # spath = os.path.join(path, child.tag)
+            for item in child:
+                if "filename" in item.attrib:
+                    wfilename = item.attrib["filename"]
+                    if wfilename == "":
+                        continue
+                    start = int(item.attrib["FileOffsetInSrc"]) * pagesize
+                    length = int(item.attrib["SizeInSectorInSrc"]) * pagesize
+                    rlength = int(item.attrib["SizeInByteInSrc"])
+                    decryptfile(key,iv,filename, path, wfilename, start, length,rlength)
+                else:
+                    for subitem in item:
+                        if "filename" in subitem.attrib:
+                            wfilename = subitem.attrib["filename"]
+                            if wfilename == "":
+                                continue
+                            start = int(subitem.attrib["FileOffsetInSrc"]) * pagesize
+                            length = int(subitem.attrib["SizeInSectorInSrc"]) * pagesize
+                            rlength = int(item.attrib["SizeInByteInSrc"])
+                            decryptfile(key,iv,filename, path, wfilename, start, length,rlength)
+        # else:
+        #    print (child.tag, child.attrib)
+    print("Done. Extracted files to " + path)
+    exit(0)
+
+
+if __name__=="__main__":
+    main()