Quick script for extracting the firmware of an Hi351C based ip camera

dump.py

import struct
import binascii

with open("firmware_HI3518C-V5-ONVIF-V2.5.0.6_20140126124709.bin", "rb") as f:
    print("     Magic:", f.read(8))
    print("   Unknown:", binascii.hexlify(f.read(4)))
    length = struct.unpack("<L", f.read(4))[0]
    print("    Length:", length)
    print("    Flags?:", struct.unpack("<L", f.read(4))[0])
    hdr_len = struct.unpack("<L", f.read(4))[0]
    print("header len:", hdr_len)
    linux_len = struct.unpack("<L", f.read(4))[0]
    print(" Linux len:", linux_len)
    print(" Checksum?:", binascii.hexlify(f.read(4)))
    f.seek(0)
    print("Dumping header image")
    hdr_img = f.read(hdr_len)
    with open("header.img", "wb") as out:
        out.write(hdr_img)
    print("Dumping uboot image")
    linux_img = f.read(linux_len)
    with open("linux.img", "wb") as out:
        out.write(linux_img)
    print("cramfs hdr:", binascii.hexlify(f.read(4)))
    cramfs_len = struct.unpack("<L", f.read(4))[0]
    print("cramfs len:", cramfs_len)
    f.seek(-8, 1)
    print("Dumping cramfs image")
    cramfs_img = f.read(cramfs_len)
    with open("root.cramfs", "wb") as out:
        out.write(cramfs_img)