objdump2shellcode/objdump2shellcode.py at master · japkettu/objdump2shellcode · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
#!/usr/bin/env python2

import re
import sys
import argparse


def nullbytes(shellcode):
    c = 0
    for byte in shellcode.split('\\x'):
        if ('00' in byte):
            c += 1
    return c

def show_info(shellcode, endiannes, arch, quiet_mode):
    if not quiet_mode:
        print "-" * 64
        print "Architecture: %s" % (arch)
        print "Endiannes: %s" % (endiannes)
        print "Length: %d" % (len(shellcode))
        print "Null bytes: %d" % (nullbytes(shellcode))
        print shellcode

    else:
        print shellcode

def detectArch(line):
    string =  line.split(' ')[-1]
    string = string.lower()
    if 'arm' in string:
        return 'arm'
    elif 'x86' in string:
        return 'x86'
    else:
        print 'Could not detect architecture! Exiting.'
        sys.exit(0)

def arm(fd, endiannes, quiet_mode):

    shellcode = ''
    code_section = False

    for line in fd:
        line = line.strip()
        if "_start" in line:
            code_section = True
            continue

        if code_section == True:
            if not quiet_mode:
                print line
            if len(line) > 5:
                if line.endswith('>:'):
                    continue
                columns = line.replace('\t',' ').split(' ')
                columns = filter(None, columns)
                code_col = columns[1].strip()
                pairs = re.findall('..',code_col)
                if endiannes == 'little':
                    pairs = pairs[::-1]
                for pair in pairs:
                    shellcode += '\\x'+pair

    return shellcode


def x86(fd, endiannes, quiet_mode):

    shellcode = ''
    code_section = False

    for line in fd:
        line = line.strip()
        if "_start" in line:
            if not quiet_mode:
                 print line
            code_section = True
            continue

        if code_section == True:
            if not quiet_mode:
                print line
            if len(line) > 5:
                if line.endswith('>:'):
                    continue
                columns = line.replace('\t',' ').split(' ')
                code_col = columns[1:columns.index('')]
                code_col = "".join(code_col)
                pairs = re.findall('..',code_col)
                if endiannes == 'little':
                    pairs = pairs[::-1]
                for pair in pairs:
                    shellcode += '\\x'+pair

    return shellcode

def main():

    ap = argparse.ArgumentParser()
    ap.add_argument('-c', '--cpu', required=False, help='set CPU architechture [arm, x86]')
    ap.add_argument('-q', '--quiet', required=False, default=False, help='reduced output', action='store_true')
    ap.add_argument('-e', '--endiannes', required=False, default='little', help='change endiannes [big, little]')
    ap.add_argument("file")
    args = vars(ap.parse_args())


    endiannes = args["endiannes"]
    shellcode = ''
    arch = args["cpu"]
    filepath = args["file"]
    quiet_mode =  args["quiet"]


    with open(filepath) as fd:

        for line in fd:
            line = line.strip()
            if not arch:
                if len(line.strip()) != 0 :
                    arch = detectArch(line)
            else:
                if arch == 'arm':
                    shellcode = arm(fd, endiannes, quiet_mode)
                if arch == 'x86':
                    shellcode = x86(fd, endiannes, quiet_mode)


        show_info(shellcode, endiannes, arch, quiet_mode)

if __name__ == '__main__':
        main()