Due to the change Pepephone ISP made last year migrating from Vodafone to Masmóvil's network, it was necessary for me to obtain an 802.1q-protocol compatible DSL router to be able to use the internet connection. This caused me to retire my Asus DSL-N55u router--which had a stability, configuration and WIFI coverage I was very happy with. So I purchased a Huawei HG556a DSL router and, since this router had a 10/100 switch and pretty mediocre WIFI speed, I also purchased a Linksys EA8500 router that would provide me with the WIFI coverage and gigabit connectivity for my devices. So I configured the Huawei HG556a router in WAN Bridge mode and connected it to the WAN port of the Linksys' router. This configuration gave me excellent performance, even more after flashing DD-WRT on the Linksys router.
Now, I have changed the internet operator, moving to a FTTH connection of 500/300 MB with Cableworld, and they installed a Huawei HG8245U router and an optical splitter whose coaxial output, connected to the house's main TV splitter, distributes the TV channels of the service. As I was very satisfied with the operation and WIFI coverage of the Linksys Ea8500 router, I configured the HG8245U router again in WAN bridge mode, and this is the way in which I have been working.
At that point several problems arised: the cableworld's HUWAEI router was huge and I lost some space in the living room furniture; the use of two devices (HUAWEI router and optical splitter) forced me to use two power plugs, which increased the entanglement of cables in general. In addition, this router had a high power consumption, which was a waste of resources, since I was not using any of its ethernet outputs (except 1 connected to the Linksys WAN router), its Wi-Fi, nor 90% of its features. So I started looking for an optical router/ONT with the following features: small sized, integrated CATV output, low power consumption and within the Huawei brand so it would be compatible with Cableworld's OLT. The perfect candidate was the Huawei HG8012H ,and in one of my trips to Portugal I was lucky enough to find one for 5€ in Cashconverters (shop price is about 80€).
I got down to work configuring this ONT with my ISP parameters, so I connected an ethernet cable between the ONT and my PC and tried to open http://192.168.1.1 in browser, but I got no response. Then I searched the internet for Huawei documents and technical files and found that for this model, the default IP address is 192.168.100.1 and the access users are telecomadmin:admintelecom and root:admin. After making the relevant IP and subnet changes in the network card of my PC, I went to http://192.168.100.1 in the browser and 'voilà', the WebUi showed and, supposedly, I would be able to start configuring my brand new ONT:
Unfortunately, none of the two access users I had found in the documentation worked. So it occurred to me pressing the reset button for 30 seconds with a paper clip with the total certainty that this would cause the default access users to be functional again. But I was wrong. After a long time trying to search the internet for a login that would allow me access to the ONT, not only did I not find it but I verified that there is very little information about this device available. As if that were not enough, I discovered that when this ONT comes directly from an ISP, it is usually blocked by them as to not allow access to the configuration, and that way the user can not reuse it with another ISP. In this case, it appeared that the ONT that I bought in Cashconverters had not been purchased directly from HUAWEI, but instead had been installed by a supplier. Things started to get complicated.
I could see that by entering 3 incorrect passwords, the router did not allow retry the login until 1 minute after, so the option of dictionaries and brute force attacks to access was discarded by the amount of time the entire process would take.
Normally many routers allow telnet access to the device as an alternative way of configuration, but in this case it was impossible and the connection closed due to lack of response from the ONT.
Trying to find some weak point in the ONT that allowed me access, I did a port scanner from my PC, with the following command:
nmap -Pn -n -p0- 192.168.100.1
It did not help much, all ports were closed except port 80 (webUi). Port 23 (telnet) was not only not open but was being filtered by the integrated firewall to further complicate things. There was nothing else I could do externally to solve this, so screwdriver in hand I ventured to examine the bowels of the bug.
Once the cover was opened and after a component identification phase, this is what I found:
Of all these components the ones that caught my attention were the serial port pads, the JTAG port and the flash memory. After a search on the internet, I deduced the pinout of both the serial port and the JTAG. They are quite common among HUAWEI router devices.
I tested JTAG port using the parallel port cable that can be seen in the previous photo but I did not get response, so I focused my efforts on the serial port. After connecting a TTL-USB converter and connecting to the virtual COM port using PutTy with a rate of 115200 symbols, I started to see the following bootlog on the screen:
HuaWei StartCode 2012.02 (Mar 25 2014 - 01:04:34)
SPI:
startcode select the uboot to load
the high RAM is :8080103c
startcode uboot boot count:0
Boot load address :0x80000
Use the UbootB to load success
U-Boot 2010.03 (R13C10 Jul 31 2015 - 14:38:54)
DRAM: 128 MB
Boot From SPI flash
Chip Type is SD5115S
SFC : cs0 unrecognized JEDEC id 00ffffff, extended id 00000000
SFC: extend id 0x300
SFC: cs1 s25sl12800 (16384 Kbytes)
SFC: Detected s25sl12800 with page size 262144, total 16777216 bytes
SFC: already protect ON !
SFC: sfc_read flash offset 0x80000, len 0x40000, memory buf 0x81fa0008
*** Warning - bad CRC, using default environment
In: serial
Out: serial
Err: serial
PHY power down !!!
[main.c__5566]::CRC:0x6a8fe445, Magic1:0x5a5a5a5a, Magic2:0xa5a5a5a5, count:0, CommitedArea:0x1, Active:0x1, RunFlag:0x0
SFC : cs0 unrecognized JEDEC id 00ffffff, extended id 00000000
SFC: extend id 0x300
SFC: cs1 s25sl12800 (16384 Kbytes)
SFC: Detected s25sl12800 with page size 262144, total 16777216 bytes
initialize flash success
Start from main system(0x1)!
CRC:0x6a8fe445, Magic1:0x5a5a5a5a, Magic2:0xa5a5a5a5, count:1, CommitedArea:0x1, Active:0x1, RunFlag:0x0
Main area (B) is OK!
CRC:0xc4e775d4, Magic1:0x5a5a5a5a, Magic2:0xa5a5a5a5, count:1, CommitedArea:0x1, Active:0x1, RunFlag:0x0
iRootfsSize to 0x47c1d4
Start copy data from 0x1c9c0054 to 0x86000000 with sizeof 0x0047c1d4 ............Done!
Bootcmd:bootm 0x1c340054 0x86000000
BootArgs:noalign mem=114M console=ttyAMA1,115200 initrd=0x86000040,0x47c194 rdinit=/linuxrc mtdparts=hi_sfc:0x40000(startcode),0x40000(bootA)ro,0x40000(bootB)ro,0x40000(flashcfg)ro,0x40000(slave_param)ro,0x200000(kernelA)ro,0x200000(kernelB)ro,0x480000(rootfsA)ro,0x480000(rootfsB)ro,0x180000(file_system),-(reserved)pcie1_sel=x1 maxcpus=0 user_debug=0x1f panic=1
U-boot Start from NORMAL Mode!
## Booting kernel from Legacy Image at 1c340054 ...
Image Name: Linux-2.6.34.10_sd5115v100_wr4.3
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 2025204 Bytes = 1.9 MB
Load Address: 81000000
Entry Point: 81000000
## Loading init Ramdisk from Legacy Image at 86000000 ...
Image Name: cpio
Image Type: ARM Linux RAMDisk Image (uncompressed)
Data Size: 4702612 Bytes = 4.5 MB
Load Address: 00000000
Entry Point: 00000000
SFC : cs0 unrecognized JEDEC id 00ffffff, extended id 00000000
SFC: extend id 0x300
SFC: cs1 s25sl12800 (16384 Kbytes)
SFC: Detected s25sl12800 with page size 262144, total 16777216 bytes
Loading Kernel Image ... SFC: sfc_read flash offset 0x340094, len 0x1ee6f4, memory buf 0x81000000
OK
OK
Starting kernel ...
Uncompressing Linux... done, booting the kernel.
Kernel Early-Debug on Level 0
V: 0xF1100000 P: 0x00010100 S: 0x00001000 T: 0
V: 0xF110E000 P: 0x0001010E S: 0x00001000 T: 0
V: 0xF110F000 P: 0x0001010F S: 0x00001000 T: 0
V: 0xF1104000 P: 0x00010104 S: 0x00001000 T: 0
V: 0xF1180000 P: 0x00010180 S: 0x00002000 T: 0
V: 0xF1400000 P: 0x00010400 S: 0x00001000 T: 12
early_init 72 [arch/arm/mach-sd5115h-v100f/core.c]
sd5115_map_io 223 [arch/arm/mach-sd5115h-v100f/core.c]
smp_init_cpus 163 [arch/arm/mach-sd5115h-v100f/platsmp.c]
sd5115_gic_init_irq 88 [arch/arm/mach-sd5115h-v100f/core.c]
sd5115_timer_init 471 [arch/arm/mach-sd5115h-v100f/core.c]
sd5115_clocksource_init 451 [arch/arm/mach-sd5115h-v100f/core.c]
twd_base :
0xF1180600
sd5115_timer_init 491 [arch/arm/mach-sd5115h-v100f/core.c]
smp_prepare_cpus 174 [arch/arm/mach-sd5115h-v100f/platsmp.c]
hi_kernel_wdt_init 207 [arch/arm/mach-sd5115h-v100f/hi_drv_wdt.c]
sd5115_init 314 [arch/arm/mach-sd5115h-v100f/core.c]
sd5115_init 320 [arch/arm/mach-sd5115h-v100f/core.c]
sd5115_init 320 [arch/arm/mach-sd5115h-v100f/core.c]
sd5115_init 327 [arch/arm/mach-sd5115h-v100f/core.c]
sd5115_init 330 [arch/arm/mach-sd5115h-v100f/core.c]
Linux version 2.6.34.10_sd5115v100_wr4.3 (root@wuhci2lslx00096) (gcc version 4.4.6 (GCC) ) #1 SMP Fri Jul 31 14:38:51 CST 2015
CPU: ARMv7 Processor [413fc090] revision 0 (ARMv7), cr=10c53c7f
CPU: VIPT nonaliasing data cache, VIPT nonaliasing instruction cache
Machine: sd5115
Memory policy: ECC disabled, Data cache writealloc
sd5115 apb bus clk is 100000000
PERCPU: Embedded 7 pages/cpu @c04d9000 s4448 r8192 d16032 u65536
pcpu-alloc: s4448 r8192 d16032 u65536 alloc=16*4096
pcpu-alloc: [0] 0
Built 1 zonelists in Zone order, mobility grouping on. Total pages: 28956
Kernel command line: noalign mem=114M console=ttyAMA1,115200 initrd=0x86000040,0x47c194 rdinit=/linuxrc mtdparts=hi_sfc:0x40000(startcode),0x40000(bootA)ro,0x40000(bootB)ro,0x40000(flashcfg)ro,0x40000(slave_param)ro,0x200000(kernelA)ro,0x200000(kernelB)ro,0x480000(rootfsA)ro,0x480000(rootfsB)ro,0x180000(file_system),-(reserved)pcie1_sel=x1 maxcpus=0 user_debug=0x1f panic=1
PID hash table entries: 512 (order: -1, 2048 bytes)
Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
Memory: 114MB = 114MB total
Memory: 107068k/107068k available, 9668k reserved, 0K highmem
Virtual kernel memory layout:
vector : 0xffff0000 - 0xffff1000 ( 4 kB)
fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB)
DMA : 0xffc00000 - 0xffe00000 ( 2 MB)
vmalloc : 0xc7800000 - 0xd0000000 ( 136 MB)
lowmem : 0xc0000000 - 0xc7200000 ( 114 MB)
modules : 0xbf000000 - 0xc0000000 ( 16 MB)
.init : 0xc0008000 - 0xc002b000 ( 140 kB)
.text : 0xc002b000 - 0xc0396000 (3500 kB)
.data : 0xc03aa000 - 0xc03c6660 ( 114 kB)
SLUB: Genslabs=11, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
Hierarchical RCU implementation.
RCU-based detection of stalled CPUs is enabled.
NR_IRQS:160
Calibrating delay loop... 747.11 BogoMIPS (lpj=3735552)
Security Framework initialized
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
Init trace_clock_cyc2ns: precalc_mult = 312500, precalc_shift = 8
Brought up 1 CPUs
SMP: Total of 1 processors activated (747.11 BogoMIPS).
hi_wdt: User-Mode!
hi_wdt: Init sucessfull!
NET: Registered protocol family 16
id:0x51151100
check_res_of_trace_clock: sched_clock() high resolution
Serial: dw uart driver
uart:0: ttyAMA0 at MMIO 0x1010e000 (irq = 77) is a AMBA/DW
uart:1: ttyAMA1 at MMIO 0x1010f000 (irq = 78) is a AMBA/DW
console [ttyAMA1] enabled
bio: create slab <bio-0> at 0
vgaarb: loaded
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
cfg80211: Calling CRDA to update world regulatory domain
Switching to clocksource timer1
NET: Registered protocol family 2
IP route cache hash table entries: 128 (order: -3, 512 bytes)
TCP established hash table entries: 4096 (order: 3, 32768 bytes)
TCP bind hash table entries: 4096 (order: 3, 32768 bytes)
TCP: Hash tables configured (established 4096 bind 4096)
TCP reno registered
UDP hash table entries: 128 (order: 0, 4096 bytes)
UDP-Lite hash table entries: 128 (order: 0, 4096 bytes)
NET: Registered protocol family 1
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
Trying to unpack rootfs image as initramfs...
Freeing initrd memory: 4592K
squashfs: version 4.0 (2009/01/31) Phillip Lougher
JFFS2 version 2.2. © 2001-2006 Red Hat, Inc.
msgmni has been set to 218
io scheduler noop registered
io scheduler deadline registered
io scheduler cfq registered (default)
brd: module loaded
mtdoops: mtd device (mtddev=name/number) must be supplied
Spi id table Version 1.22
Spi Flash Controller V300 Device Driver, Version 1.10
Spi(cs1) ID: 0x01 0x20 0x18 0x03 0x00 0x00
Spi(cs1): Block:256KB Chip:16MB (Name:S25FL128P-0)
Lock Spi Flash(cs1)!
Hisilicon flash: registering whole flash at once as master MTD
mtd: bad character after partition (p)
11 cmdlinepart partitions found on MTD device hi_sfc
Creating 11 MTD partitions on "hi_sfc":
0x000000000000-0x000000040000 : "startcode"
0x000000040000-0x000000080000 : "bootA"
0x000000080000-0x0000000c0000 : "bootB"
0x0000000c0000-0x000000100000 : "flashcfg"
0x000000100000-0x000000140000 : "slave_param"
0x000000140000-0x000000340000 : "kernelA"
0x000000340000-0x000000540000 : "kernelB"
0x000000540000-0x0000009c0000 : "rootfsA"
0x0000009c0000-0x000000e40000 : "rootfsB"
0x000000e40000-0x000000fc0000 : "file_system"
0x000000fc0000-0x000001000000 : "reserved"
Special nand id table Version 1.33
Hisilicon Nand Flash Controller V301 Device Driver, Version 1.10
PPP generic driver version 2.4.2
PPP Deflate Compression module registered
PPP BSD Compression module registered
PPP MPPE Compression module registered
NET: Registered protocol family 24
SLIP: version 0.8.4-NET3.019-NEWTTY (dynamic channels, max=256) (6 bit encapsulation enabled).
CSLIP: code copyright 1989 Regents of the University of California.
SLIP linefill/keepalive option.
Netfilter messages via NETLINK v0.30.
ip_tables: (C) 2000-2006 Netfilter Core Team
arp_tables: (C) 2002 David S. Miller
TCP cubic registered
NET: Registered protocol family 17
Freeing init memory: 140K
-=# DOPRA LINUX 1.0 #=-
-=# EchoLife WAP 0.1 #=-
-=# Huawei Technologies Co., Ltd #=-
mount file system
Loading the kernel modules:
Loading module: rng-core
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: nf_conntrack
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: xt_mark
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: xt_connmark
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: xt_MARK
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: xt_limit
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: xt_state
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: xt_tcpmss
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: nf_nat
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: ipt_MASQUERADE
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: ipt_REDIRECT
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: ipt_NETMAP
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: nf_conntrack_ipv4.ko
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Loading module: iptable_nat.ko
modprobe: chdir(2.6.34.10_sd5115v100_wr4.3): No such file or directory
Making device instances:
Setting console log message level:
Setting hostname:
Settingup the sysctl configurations:
Setting up interface lo:
Running local startup scripts.
*******************************************
--== Welcome To IAS WAP ==--
--== Huawei Technologies Co., Ltd. ==--
*******************************************
IAS WAP Ver:V800R013C10SPC182B001
IAS WAP Timestamp:2015/07/30 00:08:53
*******************************************
Start init IAS WAP basic module ....
current lastword info:Add=0xc7a06000;max_num=300;Add1=0xc7a01000;Add2=0xc7a06000;Add3=0xc7a0b000;
Init IAS WAP basic module done!
soft lockup args:snap=150; release=50; dump flag=1;
Set kmsgread process pid to:92;
UBIFS error (pid 102): ubifs_get_sb: cannot open "/dev/ubi0_13", error -22
mount: mounting /dev/ubi0_13 on /mnt/jffs2/ failed: Invalid argument
umount /mnt/jffs2
umount: can't umount /mnt/jffs2: Invalid argument
UBIFS error (pid 105): ubifs_get_sb: cannot open "/dev/ubi0_13", error -22
mount: mounting /dev/ubi0_13 on /mnt/jffs2/ failed: Invalid argument
Mount nor jffs2 in 1.sdk_init...
fenghe.linux4.3
Get kernel version:2.6.34
Rootfs time stamp:2015-07-31_14:40:38
SVN label(ont):/etc/rc.d/rc.start/1.sdk_init.sh: line 50: can't create /proc/sys/vm/pagecache_ratio: nonexistent directory
User init start......
Loading the SD5115V100 modules:
SYSCTL module is installed
PIE module is installed
GPIO module is installed
SPI module is installed
I2C module is installed
DP module is installed
MDIO module is installed
TIMER module is installed
UART module is installed
HW module is installed
ifconfig eth0 hw ether 18:C5:8A:XX:XX:XX
Loading the EchoLife WAP modules: LDSP
COMMON For LDSP Install Successfully...
cut kernel config
major-minor:10-58
mknod: /dev/hlp: File exists
GPIO For LDSP Install Successfully...
sh: 0: unknown operand
------ SOC is 5115 S PILOT ------
<ldsp>board version is 5
<ldsp>pcb version is 0
<ldsp>orig board version is 5
CHIPADP-SD5115 BASIC For LDSP Install Successfully...
CHIPADP-SD5115 EXT For LDSP Install Successfully...
I2C For LDSP Install Successfully...
LSW L2 For LDSP Install Successfully...
LSW L3 For LDSP Install Successfully...
DEV For LDSP Install Successfully...
[DM]:ae_chip[0]=4,ae_chip[1]=255,ae_chip[2]=255,ae_chip[3]=0
[DM]:board_ver=5,pcb_ver=0
hw_dm_init_data successfully...
[ /mnt/jffs2/boardinfocustom.cfg not exsit ! not need deal.]
hw_dm_pdt_init successfully...
hw_feature_init begin...
hw_feature_proc_init begin...
hw_feature_data_init begin...
ac_cfgpath is not null,acTmpBuf=/etc/wap/customize/ptvdfb_ft.cfg.....!
ac_hard_cfgpath is not null, acTmpBuf=/mnt/jffs2/hw_hardinfo_feature.bak.....!
ac_cfgpath is not null,acTmpBuf=/etc/wap/customize/spec_ptvdfb.cfg.....!
ac_hard_cfgpath is not null, acTmpBuf=/mnt/jffs2/hw_hardinfo_spec.bak.....!
hw_feature_init Successfully...
pots_num=0
ssid_num=0
usb_num=0
hw_route=0
l3_ex=1
ipv6=0
Read MemInfo Des: 1118
SPI For LDSP Install Successfully...
UART For LDSP Install Successfully...
BATTERY For LDSP Install Successfully...
OPTIC For LDSP Install Successfully...
PLOAM For LDSP Install Successfully...
GMAC For LDSP Install Successfully...
KEY For LDSP Install Successfully...
LED For LDSP Install Successfully...
RF For LDSP Install Successfully...
Loading BBSP L2 modules:
PTP For BBSP Install Successfully...
hw_igmp_kernel Install Successfully...
dhcp_module_init load success !
pppoe_module_init load success !
hw_ringchk_kernel Install Successfully...
hw_portchk_kernel Install Successfully...
l2base For BBSP Install Successfully...
vbr_unicast_car:50
vbr_unicast_car:50
vbr_unicast_car:50
Pktdump init Install Successfully...
hw_cpu_usage_install
[ker_L2M_CTP] for bbsp Install Successfully...
EMAC For LDSP Install Successfully...
MPCP For LDSP Install Successfully...
Loading BBSP L2_extended modules:
hw_ethoam_kernel Install Successfully...
l2ext For BBSP Install Successfully...
Dosflt For BBSP Install Successfully...
vlanflt_module_init load success !
l3base for bbsp Install Successfully...
1.sdk_init.sh close core dump, flag=
Start ldsp_user...0
<LDSP> system has no slave space for bob
<LDSP_CFG> Set uiUpMode=1 [1:GPON,2:EPON,4:AUTO]
SD511X test self OK
Extern Lsw test self NoCheck
Optic test self OK
WIFI test self NoCheck
PHY[1] test self OK
PHY[2] test self OK
PHY[3] test self OK
PHY[4] test self OK
PHY[5] test self NoCheck
PHY[6] test self NoCheck
LINE = 204, FUNC = hi_kernel_i2c_burst_read_bytes
read data is over time
<LDSP> common optic,the last i2c error is normal,donot worry
<LDSP> uiRet = 2 pcNodeName = Cfg1 Cmd = 20005000 Length = 10 Value = be8406b2
GPON init success !
ssmp bbsp igmp amp ethoam omci
Start start pid=252; uiProcNum=6;
InitFrame omci; PID=256; state=0; 15.084;
InitFrame omci; PID=256; in state=0; 15.084;
InitFrame omci; PID=256; out state=0; 15.085;
InitFrame ssmp; PID=253; state=0; 15.172;
InitFrame ssmp; PID=253; in state=0; 15.173;
uiCfgAddr:c0000
<db/hw_xml_dbmain.c:7713>acChooseWord:NOCHOOSE UserChoiceFlag:-1 Updateflag:-1
InitFrame bbsp; PID=254; state=0; 15.744;
InitFrame bbsp; PID=254; in state=0; 15.745;
InitFrame bbsp; PID=254; out state=0; 15.747;
InitFrame ethoam; PID=258; state=0; 15.750;
InitFrame ethoam; PID=258; in state=0; 15.750;
InitFrame ethoam; PID=258; out state=0; 15.752;
InitFrame igmp; PID=257; state=0; 15.759;
InitFrame igmp; PID=257; in state=0; 15.759;
InitFrame igmp; PID=257; out state=0; 15.759;
InitFrame amp; PID=255; state=0; 15.974;
InitFrame amp; PID=255; in state=0; 15.975;
InitFrame amp; PID=255; out state=0; 15.976;
<db/hw_xml_dbmain.c:8784>acFilePath:/etc/wap/hw_aes_tree.xml pstRoot:0x0
<db/hw_xml_dbmain.c:9068>acFilePath:/etc/wap/hw_aes_tree.xml pstRoot:0x3835ebc4
pfFuncHandle ERR. uiRet:ffffffff;
pfFuncHandle ERR. uiRet:ffffffff;
pfFuncHandle ERR. uiRet:ffffffff;
pfFuncHandle ERR. uiRet:ffffffff;
pfFuncHandle ERR. uiRet:ffffffff;
pfFuncHandle ERR. uiRet:ffffffff;
pfFuncHandle ERR. uiRet:ffffffff;
pfFuncHandle ERR. uiRet:ffffffff;
pfFuncHandle ERR. uiRet:ffffffff;
pfFuncHandle ERR. uiRet:ffffffff;
pfFuncHandle ERR. uiRet:ffffffff;
<db/hw_xml_dbmain.c:7100>[HW_XML_DBOnceSave] Set DB Auto Save in 12000 ticks.
Reset reason: unknown reason, except oom, watchdog and lossing power!In many cases, this type of serial connection ends up in a login screen in which credentials are requested in order to operate and configure certain aspects of the device. However, this was not the case. No doubt this ONT was fortified so as not to alter its configuration in any way. In any case there was an information in the bootlog that caught my attention:
Creating 11 MTD partitions on "hi_sfc":
0x000000000000-0x000000040000 : "startcode"
0x000000040000-0x000000080000 : "bootA"
0x000000080000-0x0000000c0000 : "bootB"
0x0000000c0000-0x000000100000 : "flashcfg"
0x000000100000-0x000000140000 : "slave_param"
0x000000140000-0x000000340000 : "kernelA"
0x000000340000-0x000000540000 : "kernelB"
0x000000540000-0x0000009c0000 : "rootfsA"
0x0000009c0000-0x000000e40000 : "rootfsB"
0x000000e40000-0x000000fc0000 : "file_system"
0x000000fc0000-0x000001000000 : "reserved"Here you can see that the flash memory is subdivided into several partitions with different purposes. If in any of the partitions I could be able to locate the file with the current configuration of the router, I could modify it to suit my interests and even see the users enabled in the Webui, enable telnet or any other aspect. In many Huawei routers, the file in question is called 'hw_ctree.xml', which is precisely the file that is generated when exporting a configuration backup from the web administration. So, discarded the JTAG port and the serial port as access doors, there was only one option to focus all my attention: flash memory. I examined the serigraphed letters with a magnifying glass and I could see that it was a Spansion S25FL128P flash memory. So datasheet in hand I launched myself to scrutinize their interiors feeling that access to the router had already become a personal issue.
To make a flash dump I found a specific utility for this type of flash chips called "Flashrom" that supports a large number of programmers. Luckily, I had one of them, a Microchip Pickit2 that I had forgotten in a drawer. So, with the pinout of the chip extracted from the datasheet, and the router completely disconnected from the power source (the programmer powers the chip itself) I started connecting the programmer to the chip with a SOIC16 clip (Pomona 5252). The connection schematic is as follows:
Once the programmer-chip connection was made, I connected the programmer to the USB port and made the flash dump by executing the command:
logon@logonlap:~$sudo flashrom -p pickit2_spi -r flashdump.bin -c "S25FL128P......0"with the parameter "-p" we specify the programmer we are using to read the flash memory, in my case as I mentioned it is a pickit2 and with the parameter "-c" we define the chip that we are going to read. After about half an hour, the reading process ended and I already had the chip dump on my PC, ready to be examined.
Once the flash memory has been dumped in a file, we must separate the file in their respective original partitions, in order to analyze each of them with greater precision. To do this, we first need to calculate the size of each partition, that is, subtract the offset from the end of the partition to the start offset of the partition. In this way, we obtain the following partition sizes:
"startcode" : 0x000000000000-0x000000040000 => 0x00040000 bytes
"bootA" : 0x000000040000-0x000000080000 => 0x00040000 bytes
"bootB" : 0x000000080000-0x0000000c0000 => 0x00040000 bytes
"flashcfg" : 0x0000000c0000-0x000000100000 => 0x00040000 bytes
"slave_param" : 0x000000100000-0x000000140000 => 0x00040000 bytes
"kernelA" : 0x000000140000-0x000000340000 => 0x00200000 bytes
"kernelB" : 0x000000340000-0x000000540000 => 0x00200000 bytes
“rootfsA" : 0x000000540000-0x0000009c0000 => 0x00480000 bytes
"rootfsB" : 0x0000009c0000-0x000000e40000 => 0x00480000 bytes
"file_system" : 0x000000e40000-0x000000fc0000 => 0x00180000 bytes
"reserved" : 0x000000fc0000-0x000001000000 => 0x00040000 bytesAnd now we extract every partitión from the dump using the command:
dd if=flashdump.bin bs=1 status=none skip=$((PARTITION_START)) count=$((PARTITION_SIZE)) of=PARTITION_NAME.binIn my case, these are the commands I ran:
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x00000000)) count=$((0x00040000)) of=1startcode.bin
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x00040000)) count=$((0x00040000)) of=2bootA.bin
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x00080000)) count=$((0x00040000)) of=3bootB.bin
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x000c0000)) count=$((0x00040000)) of=4flashcfg.bin
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x00100000)) count=$((0x00040000)) of=5slave_param.bin
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x00140000)) count=$((0x00200000)) of=6kernelA.bin
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x00340000)) count=$((0x00200000)) of=7kernelB.bin
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x00540000)) count=$((0x00480000)) of=8rootfsA.bin
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x009c0000)) count=$((0x00480000)) of=9rootfsB.bin
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x00e40000)) count=$((0x00180000)) of=Afile_system.bin
logon@logonlap:~$dd if=flashdump.bin bs=1 status=none skip=$((0x00fc0000)) count=$((0x00040000)) of=Breserved.binNote that at the beginning of each partition name I have added a sequence in the form of hexadecimal numbers to maintain the order of the partitions and thereby facilitate the subsequent task of joining them in a single file.
The configuration files that I am interested into to access the router's web as well as to enable other functions such as access via telnet reside in "AFile System.bin" partition. It is the partition that the router has with read and write permissions at runtime precisely to be able to save changes. If we think of a generic router in which we change for example the name of the WIFI network, the partition where that name is stored must have read and write permissions, because otherwise we could not modify the name of the WIFI ever.
To analyze the content of said partition "A", we will use a powerful and recognized tool to examine firmwares and dumps called "Binwalk" that will be of great help to us. But before launching it personally I always prefer to take a look at the hexadecimal content of what I am going to try to analyze and build a visual map of the data and the empty spaces. After opening the file with a hexadecimal editor I discover that the structure is like this:
We will separate each of these areas into separate files to facilitate the subsequent identification of each of the two data blocks as well as the future task of rebuilding partition "A". For this we use the dd command again:
logon@logonlap:~$dd if=Afile_system.bin bs=1 status=none skip=$((0x0)) count=12 of=Afile_system_trim1.bin
logon@logonlap:~$dd if=Afile_system.bin bs=1 status=none skip=$((0x100000)) count=493216 of=Afile_system_trim2.binAt this point is when Binwalk comes into play, let's see what identifies in each of these two blocks that we just separated:
logon@logonlap:~$binwalk Afile_system_trim1.bin
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
0 0x0 JFFS2 filesystem, little endianlogon@logonlap:~$binwalk Afile_system_trim2.bin
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
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406324 0x63334 Zlib compressed data, compressed
406848 0x63540 Zlib compressed data, compressed
407268 0x636E4 Zlib compressed data, compressed
407384 0x63758 Zlib compressed data, compressed
407500 0x637CC Zlib compressed data, compressed
407616 0x63840 Zlib compressed data, compressed
407732 0x638B4 Zlib compressed data, compressed
407848 0x63928 Zlib compressed data, compressed
407964 0x6399C Zlib compressed data, compressed
408080 0x63A10 Zlib compressed data, compressed
408196 0x63A84 Zlib compressed data, compressed
408312 0x63AF8 Zlib compressed data, compressed
408428 0x63B6C Zlib compressed data, compressed
408544 0x63BE0 Zlib compressed data, compressed
408660 0x63C54 Zlib compressed data, compressed
408776 0x63CC8 Zlib compressed data, compressed
408892 0x63D3C Zlib compressed data, compressed
409008 0x63DB0 Zlib compressed data, compressed
409124 0x63E24 Zlib compressed data, compressed
409240 0x63E98 Zlib compressed data, compressed
409356 0x63F0C Zlib compressed data, compressed
409472 0x63F80 Zlib compressed data, compressed
409588 0x63FF4 JFFS2 filesystem, little endian
409964 0x6416C Zlib compressed data, compressed
411708 0x6483C Zlib compressed data, compressed
412432 0x64B10 Zlib compressed data, compressed
413096 0x64DA8 Zlib compressed data, compressed
413740 0x6502C Zlib compressed data, compressed
414412 0x652CC Zlib compressed data, compressed
415048 0x65548 Zlib compressed data, compressed
415732 0x657F4 Zlib compressed data, compressed
416380 0x65A7C Zlib compressed data, compressed
417052 0x65D1C Zlib compressed data, compressed
417740 0x65FCC Zlib compressed data, compressed
418436 0x66284 Zlib compressed data, compressed
419076 0x66504 Zlib compressed data, compressed
419764 0x667B4 Zlib compressed data, compressed
420424 0x66A48 Zlib compressed data, compressed
421128 0x66D08 Zlib compressed data, compressed
421812 0x66FB4 Zlib compressed data, compressed
422520 0x67278 Zlib compressed data, compressed
423216 0x67530 Zlib compressed data, compressed
423936 0x67800 Zlib compressed data, compressed
425212 0x67CFC Zlib compressed data, compressed
426844 0x6835C Zlib compressed data, compressed
428104 0x68848 Zlib compressed data, compressed
429316 0x68D04 Zlib compressed data, compressed
431032 0x693B8 Zlib compressed data, compressed
432528 0x69990 Zlib compressed data, compressed
434200 0x6A018 Zlib compressed data, compressed
435132 0x6A3BC Zlib compressed data, compressed
452312 0x6E6D8 JFFS2 filesystem, little endian
460200 0x705A8 JFFS2 filesystem, little endian
493096 0x78628 JFFS2 filesystem, little endianFirst file seems to be used only as an "identifier" of the format of the second one, because if I extract the file trim1 with the "-e" modifier of binwalk, no content appears. Certainly we can not expect many compressed files within a file of only 12 bytes in size. So for the moment we ignore that identifier.
Regarding the second file, binwalk identifies a chaos mixture of compressed files and JFFS2 file systems. This type of output is a clear indication that false positives are being detected. Let's help Binwalk a bit telling him to just try to identify JFFS2 file systems in Afile_system_trim2.bin, since I suspect that Zlib compressed files are included within the JFFS2 system itself:
logon@logonlap:~$binwalk -y jffs2 Afile_system_trim2.bin
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
0 0x0 JFFS2 filesystem, little endianBingo!. This way Binwalk identifies the entire area as a single file system, so we can proceed to extract it and expect consistent results. We add the parameter "-e" to extract:
logon@logonlap:~$sudo binwalk -y jffs2 -e Afile_system_trim2.binI have extracted the file system as superuser to make sure I don't lose sensible data like file permissions or symbolic links. IMPORTANT: Binwalk needs the 'jefferson' utility installed (https://github.com/sviehb/jefferson) in order to be able to extract this kind of file system. Inside the directory ./Afile_system_trim2.bin.extracted/jffs2-root we find the extracted files:
You can check highlighted in blue the necessary files needed to edit to vary webUi access parameters and router services while the files that must be edited to convert the ONT into a universal device, without personalization of the ISP are highlighted in pink. The problem with the firsts is that, in my case, if I open them with a text editor they turn out to be encrypted and their content is not understandable. Luckily this type of encryption has already been hacked by the community and there is a utility called "aescrypt2_huawei" that allows decryption and encryption of these file. We execute the following command on each of the files highlighted in blue to decrypt them:
logon@logonlap:~$aescrypt2_huawei 1 INPUT_FILE OUTPUT_FILEThe changes we need to make to the files after decrypting them are the following:
Before:
TELNETLanEnable="0"After:
TELNETLanEnable="1"Set default Huawei routers users (root:admin and telecomadmin:admintelecom). Here we can see the credentials that the router was using until now (root:80%V0d@%W31%12)
Before:
<X_HW_WebUserInfo NumberOfInstances="1">
<X_HW_WebUserInfoInstance InstanceID="1" UserName="root" Password="80%V0d@%W31%12" UserLevel="1" Enable="1" ModifyPasswordFlag="1"/>
</X_HW_WebUserInfo>After:
<X_HW_WebUserInfo NumberOfInstances="2">
<X_HW_WebUserInfoInstance InstanceID="1" UserName="root" Password="admin" UserLevel="1" Enable="1" ModifyPasswordFlag="1"/>
<X_HW_WebUserInfoInstance InstanceID="2" UserName="telecomadmin" Password="admintelecom" UserLevel="0" Enable="1" ModifyPasswordFlag="0"/>
</X_HW_WebUserInfo>In case that the password field is a string composed of hexadecimal characters it means that what is shown is not a clear password, but the result of applying a HASH function to it. To generate a hash with the desired password we must apply the function MD5 (PASSWORD) if the length of the original field is 28 bytes or the function SHA256 (MD5 (PASSWORD)) if the length of the field is 64 bytes. The file ./fs_1/CfgFile_Backup/V300R013C10SPC128B217.xml had the passwords in HASH format with 64 bytes in length in my ONT, so the access users section in that particular file was edited as follows: After:
<X_HW_WebUserInfo NumberOfInstances="2">
<X_HW_WebUserInfoInstance InstanceID="1" UserName="root" Password="465c194afb65670f38322df087f0a9bb225cc257e43eb4ac5a0c98ef5b3173ac" UserLevel="1" Enable="1" ModifyPasswordFlag="1" PassMode="2"/>
<X_HW_WebUserInfoInstance InstanceID="2" UserName="telecomadmin" Password="402931e04c03e24d360477a9f90b9eb15777e154360f06228be15c37679016ef" UserLevel="0" Enable="1" ModifyPasswordFlag="1" PassMode="2"/>
</X_HW_WebUserInfo>If we want to the edit credentials for the Telnet user, we have to edit them in the "<X_HW_CLIUserInfoInstance" part of the XML file.
Before:
IPInterfaceIPAddress="192.168.100.1"After:
IPInterfaceIPAddress="192.168.1.1"Before:
<X_HW_ProductInfo originalVersion="V300R013C10SPC128C0009150076" currentVersion="V300R013" customInfo="PTVDFB" customInfoDetail="PTVDFB"/>After:
<X_HW_ProductInfo originalVersion="V300R013C10SPC128C0009150076" currentVersion="V300R013" customInfo="COMMON" customInfoDetail="COMMON"/>Before:
<LANHostConfigManagement DHCPServerConfigurable="1" DHCPServerEnable="1"After:
<LANHostConfigManagement DHCPServerConfigurable="1" DHCPServerEnable="0"Now we have to do the reverse step with these files, that is, re-encrypt them and replace the original files with the new ones that we have modified. To re-encrypt the modified files we use the command:
aescrypt2_huawei 0 INPUT_FILE OUTPUT_FILENow we focus on the files we marked in pink on the JFFS2 file system tree. These files are not encrypted, so its modification is much easier. As I explained previously, what we are looking for by editing them is to establish with it the ONT as universal without the personalization, in this case, of Vodafone Portugal. These are the changes we need to make:
hw_boardinfo BEFORE:
obj.id = "0x0000001b" ; obj.value = "PTVDFB";hw_boardinfo AFTER:
obj.id = "0x0000001b" ; obj.value = "COMMON";hw_boardinfo.bak BEFORE:
obj.id = "0x0000001b" ; obj.value = "PTVDFB";hw_boardinfo.bak AFTER:
obj.id = "0x0000001b" ; obj.value = "COMMON";customize.txt BEFORE:
COMMON PTVDFBcustomize.txt AFTER:
COMMON COMMONrecovername BEFORE:
recover_common.shrecovername AFTER:
recover_common.shThe script pointed by "recovername" is used when pressing the reset button for 30 seconds. In my case PTVDFB uses the same reset script as the universal ONT, but other ONTs with different customizations from other ISPs may use a different script (Ex: recover_claro.sh). If that's the case, we should modify the "recovername" file to set "recover_common.sh" as reset script.
Here we have finished all the modifications of the JFFS2 file system, what we have to do now is to repack everything again. The commands that we need to execute are:
Pack the JFFS2 file system:
logon@logonlap:~$mkfs.jffs2 -l -q --root=./Afile_system_trim2.bin.extracted/jffs2-root/fs_1 -o new_jffs2.binCreate an 'empty' container filled with "FF" to build a new "Afile_system_MODDED.bin" with our changes, keeping the original size of Afile_system.bin:
logon@logonlap:~$dd if=/dev/zero bs=1 count=$((0x00180000)) | tr "\000" "\377" > Afile_system_MODDED.binInsert the "identifier" we split before in the new container in its original offset (0):
logon@logonlap:~$dd if=Afile_system_trim1.bin bs=1 status=none of=Afile_system_MODDED.bin conv=notruncInsert the new JFFS2 file system in the new container in its original offset (0x100000):
logon@logonlap:~$dd if=new_jffs2.bin bs=1 status=none seek=$((0x100000)) of=Afile_system_MODDED.bin conv=notruncRebuild the whole flash, using our Afile_system_MODDED.bin instead of the original "A" partition:
logon@logonlap:~$cat 1startcode.bin 2bootA.bin 3bootB.bin 4flashcfg.bin 5slave_param.bin 6kernelA.bin 7kernelB.bin 8rootfsA.bin 9rootfsB.bin Afile_system_MODDED.bin Breserved.bin > fullflash_MODDED.binWith this we have created the file "fullflash_MODDED.bin" that contains all the partitions that the Huawei ONT needs to work. What we have to do with it is to burn it into the ONT's flash and check if the modifications we made do work. So, we reconnect the programmer (Pickit2 in my case) to the flash chip using the SOIC16 clip and execute:
logon@logonlap:~$sudo flashrom -p pickit2_spi -w fullflash_MODDED.bin -c "S25FL128P......0"
flashrom p1.0-62-ga3ab6c6 on Linux 4.13.0-37-generic (x86_64)
flashrom is free software, get the source code at https://flashrom.org
Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns).
Found Spansion flash chip "S25FL128P......0" (16384 kB, SPI) on pickit2_spi.
===
This flash part has status UNTESTED for operations: PROBE READ ERASE WRITE
The test status of this chip may have been updated in the latest development
version of flashrom. If you are running the latest development version,
please email a report to [email protected] if any of the above operations
work correctly for you with this flash chip. Please include the flashrom log
file for all operations you tested (see the man page for details), and mention
which mainboard or programmer you tested in the subject line.
Thanks for your help!
Reading old flash chip contents... done.
Erasing and writing flash chip... Erase/write done.
Verifying flash... VERIFIED.We connect the router to the power source, the ONT to our LAN and we go to the address http://192.168.1.1:
Enter the superuser credentials we established in config files (telecomadmin / admintelecom) and click "LOGIN":
We did it !!! We have managed to access the webui starting from a completely unknown user access and password situation (which was not re-established even with a hard-reset of the device) and with blocked telnet access. Will we be able to connect also via telnet? Let's see:
Yes! I used root:admin credentials for Telnet access, if we wanted to modify these credentials, we could have done it by editing the section <X_HW_CLIUserInfoInstance in the XML files. The Telnet console gives us access to the Huawei WAP console, which is a console with custom commands to set different configurations. Not to be confused with a standard BASH console in linux, here we can not use "dir", "mkdir" or any linux console command.
At this point I only need to configure the SN of the router HG8245U that my ISP installed, in this hacked HG8012H ONT. The SN of the router is used as an identification parameter and access restriction to the Internet network of the ISP. With an SN that is not previously registered in the whitelist of the internet operator's OLT, the router will never do synchronize with ISP. So we must configure the SN of the router HG8245U in the ONT HG8012H going to the menu "System Tools"> "ONT Authentication" and clicking "Apply" after entering the SN.
After this, I notice that the LED PON flashes in green a few seconds and finally remains fixed in that same color, that is, the ONT has managed to authenticate in ISP's OLT. At the same time, I observe that on my Linksys EA8500 router I get a public IP, so finally I have my Internet connection working, occupying much less space in the furniture and consuming less energy.
Not yet. When I turn on my TV I realise no TV channels are visible at all and the CATV LED on the ONT remains off. At first I imagined that connecting a coaxial cable to the CATV output will turn on the CATV LED, but it was not like this. I also I did not see any option in the web interface to activate said television output. Why? It seems that the system is designed in this way: just after the ONT synchronizes with the OLT, the OLT sends the order to activate the TV module in the routers of clients that have contracted that TV service. If a client has not contracted the TV service, then the OLT will not send the instruction to activate said CATV module and therefore the client will not be able to see the TV through said output. In my case, I have contracted the TV service with ISP, but they use a passive device to extract the television channels from the optical fiber (Mininode SR2020AW, see first pic in top of this article) so the OLT sends by default the CATV = Off instruction to the subscribers, as in this ISP there's no client with an ONT with CATV integrated in.
After colliding with the wall of lack of information about the CATV module integrated in some of the Huawei devices and multiple tests, I finally discovered a way to activate the TV in the ONT:
telnet 192.168.1.1
Login: root
Password: admin
WAP> su
SU_WAP> set rf switch onThese commands must be entered AFTER the ONT synchronizes with the OLT. If we execute it before the synchronization, the CATV module will turn off again after synchronization since as we said, the OLT of my ISP sends the instruction CATV = Off by default.
The disadvantages of activating the CATV module in this way are clear: each time the ONT power source turns off, voluntarily or involuntarily, the CATV module will remain OFF until the Ethernet cable that goes from the ONT to the WAN port of the Linksys router is disconnected, and the cable coming from my PC is connected to the ONT and then the previous Telnet commands are run. And after this, all the cables should be connected as they were to be able to have an internet connection again. Not very practical, we have to somehow automate the activation of the television output, and this involves modifying the firmware even more.
What we now want to achieve is not to edit the configuration of the device (as we did with the partition "A"), but modify the internal operation of the device itself. This will be achieved by editing the root file system (ROOTFS), that is partition "8" and "9" according to the map initially shown. With a simple comparison of crc32 I verify that 8rootfsA.bin is identical to 9rootfsB.bin, so I will focus on 8rootfsA.bin. As we did in the past, I now make a data map of partition "8":
It seems that all the information in this partition is condensed in the upper part, without intermediate gaps, so in principle we are not going to perform additional separations. Let's see what binwalk detects:
logon@logonlap:~$binwalk 8rootfsA.bin
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
84 0x54 uImage header, header size: 64 bytes, header CRC: 0xEADB737A, created: 2016-04-18 13:19:13, image size: 3805184 bytes, Data Address: 0x0, Entry Point: 0x0,data CRC: 0xE731B6C3, OS: Linux, CPU: ARM, image type: RAMDisk Image, compression type: none, image name: "squashfs"
148 0x94 Squashfs filesystem, little endian, version 4.0, compression:lzma, size: 3802857 bytes, 1005 inodes, blocksize: 131072 bytes, created: 2016-04-18 13:19:13
4504532 0x44BBD4 MySQL ISAM index file Version 6From here we can deduce several things with very simple calculations. First Binwalk detected a header of type Uimage at offset 0x54, but the data according to the previous map started directly at offset 0. This means that before the uimage header we have some type of header not identified by Binwalk. We will call that piece between offset 0x00 and 0x54 "Huawei_header". Then there is an lzma compressed Squashfs v4.0 file system. Third, there is a structure of MySQL type ISAM at offset 0x44BBD4. If we observe the data detected by Binwalk in the Uimage header, one of them tells us that the squashfs system with which this header is associated has a size of 3805184 bytes, while the size that Binwalk has detected in the squashfs system itself is 3802857 bytes. This means that Binwalk has incorrectly identified the squashfs system length: the squashfs system does not end at 0x3A077D (0x94 + 3802857 = 0x94 + 0x3A06E9 = 0x3A077D) but at offset 0x3A1094 (0x94 + 3805184 = 0x94 + 0x3A1000 = 0x3A1094). Next there are unidentified data that ends at offset 0x47C228. Binwalk is not able to identify it even after extracting the section [0x3A1094 0x47C228]. We will call this part "Huawei_footer.bin" and will add it at the end of the 8rootfsA_MODDED.bin repackage process. With all this, we can fine-tune the initial map of 8rootfsA.bin and it would look like this:
UPDATE: After some tests updating HG8012H firmware I understood that there's no "Huawei_footer" at all in partition "8", this data was in fact remains of older and bigger squahfs file systems. When one rootfs update takes place via an official firmware update, the unused space that goes from squashfs end to partition "8" end doesn't get formatted to "FF....", so we can assume that this Huawei_footer garbage is empty space like the next area is. Then we can show partition "8" structure as:
We proceed to split each area using dd:
logon@logonlap:~$dd if=8rootfsA.bin bs=1 status=none skip=$((0x0)) count=84 of=8rootfsA_Huawei_header.bin
logon@logonlap:~$dd if=8rootfsA.bin bs=1 status=none skip=$((0x54)) count=64 of=8rootfsA_Uimage_header.bin
logon@logonlap:~$dd if=8rootfsA.bin bs=1 status=none skip=$((0x94)) count=3805184 of=8rootfsA_squashfs.binAnd we extract the squashfs file system with binwalk:
logon@logonlap:~$binwalk -e 8rootfsA_squashfs.binThe directory tree extracted at./8rootfsA.bin.extracted/squashfs-root is the following: (IMPORTANT: in order for binwalk to extract this type of file system we need to have 'squashfs-tools' package installed in our system)
We are going to edit the file ./8rootfsA.bin.extracted/squashfs-root/etc/rc.d/rc.start/1.sdk_init.sh, which is the last script that is executed during the boot of the device, to invoke a new script that will allow us to invoke the process that will activate the CATV output as well as execute other commands that we may need in the future, without risk of breaking the 1.sdk_init.sh file in future editions. So I insert the following two lines in the final part, just before the infinite processes:
#echo -n "Activate CATV output"
/bin/start_CATV.sh &
Then we create a file called "start_CATV.sh" in "/bin/" and insert the following lines inside:
#/bin/sh
#wait to boot
sleep 80
#set catv output on
{ sleep 1; echo ""; sleep 3; echo "root"; sleep 3; echo "admin"; sleep 3; echo "su"; sleep 3; echo "set rf switch on"; sleep 3; echo "quit"; sleep 3; echo "quit"; } | console.shThe 80-second timeout is to make sure that the ONT has finished booting and synchronizing with the ISP. The next line launches a local telnet session, which connects to the Huawei WAP console and writes line by line the necessary text to activate the CATV output.
Set exec permissions to "start_CATV.sh":
logon@logonlap:~$chmod +x start_CATV.shOnce this is done, it's time to repack the squashfs system. For this we will need the mksquashfs utility with support for LZMA compression compiled in (mksquashfs belongs to the squashfs-tools package, but in ubuntu repositories this utility is not compiled with LZMA compression enabled. You can locate the binary with the LZMA compression enabled in the "Files" section of this project). We pack with the command:
logon@logonlap:~$sudo mksquashfs ./8rootfsA.bin.extracted/squashfs-root/ new_squashfs.bin -comp lzma -all-rootBoth the Uimage header and the Huawei header have some CRC32 checks that we must patch so that the file system is recognized as valid by the router, so we will need to execute the following commands and write down the output generated:
new_squashfs.bin CRC32:
logon@logonlap:~$crc32 new_squashfs.binnew_squashfs.bin length (4 bytes format):
logon@logonlap:~$printf '%08x\n' $(stat -c '%s' new_squashfs.bin)Open the file 8rootfsA_Uimage_header.bin with an hexadecimal editor and search for the sequence "27 05 19 56 UU UU UU UU VV VV VV VV WW WW WW WW XX XX XX XX YY YY YY YY ZZ ZZ ZZ ZZ". We must replace "ZZ ZZ ZZ ZZ" with the CRC32 of new_squashfs.bin and "WW WW WW WW" with the length of the new_squashfs.bin file. Once this is done, we modify the sequence "UU UU UU UU" with "00 00 00 00" and save the file.
8rootfsA_Uimage_header.bin CRC32:
logon@logonlap:~$crc32 8rootfsA_Uimage_header.binNow we reopen 8rootfsA_Uimage_header.bin and replace again the last sequence "00 00 00 00" that we added to replace "UU UU UU UU" with the CRC32 obtained in the last command.
Join 8rootfsA_Uimage_header.bin and new_squashfs.bin:
logon@logonlap:~$cat 8rootfsA_Uimage_header.bin new_squashfs.bin > 8rootfsA_UH_SFS.binNow we create a 8-byte sequence concatenating the output of the following two comands:
8rootfsA_UH_SFS.bin length (4 bytes format) reversed by 2:
logon@logonlap:~$printf '%08x\n' $(stat -c '%s' 8rootfsA_UH_SFS.bin) | fold -w2 | tac | tr -d "\n"; echo ""8rootfsA_UH_SFS.bin CRC32 reversed by 2:
logon@logonlap:~$crc32 8rootfsA_UH_SFS.bin | fold -w2 | tac | tr -d "\n"; echo ""We now open the file 8rootfsA_Huawei_header.bin with an hexadecimal editor and modify exactly its last 8 bytes with the concatenated string we just created.
Join 8rootfsA_Huawei_header.bin and 8rootfsA_UH_SFS.bin into a single file:
logon@logonlap:~$cat 8rootfsA_Huawei_header.bin 8rootfsA_UH_SFS.bin > 8rootfsA_nopad.bin
We already have the partition almost rebuilt, we just have to add "FF..." to complete all the size the partition "8" had initially. Create the FF container with all the required size:
logon@logonlap:~$dd if=/dev/zero bs=1 count=$((0x00480000)) | tr "\000" "\377" > 8rootfsA_MODDED.binInsert our modded "8" partition in the container in the original position (offset 0):
logon@logonlap:~$dd if=8rootfsA_nopad.bin bs=1 status=none of=8rootfsA_MODDED.bin conv=notruncThe last step of reconstruction is to merge all the partitions into a single file. As we said at the beginning that "8rootfsA.bin" was a 1:1 copy of "9rootfsB.bin", I add the first twice:
logon@logonlap:~$cat 1startcode.bin 2bootA.bin 3bootB.bin 4flashcfg.bin 5slave_param.bin 6kernelA.bin 7kernelB.bin 8rootfsA_MODDED.bin 8rootfsA_MODDED.bin Afile_system_MODDED.bin Breserved.bin > fullflash_MODDED.binRepeat the process of programming this dump in the flash chip using Flashrom (as we did with the first modification of the partition "A"). Turn on the router and:
The CATV module starts automatically and I can see the channels on TV.
This is all, I suppose that this whole process can be easily adapted to other router models to carry out certain modifications. I hope you found the tutorial interesting. Thanks for reading. Logon
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