编码基础 – 青嵐

多个进制组合编码

用脚本进行转换（python2）

import binascii

text = 'd87 x65 x6c x63 o157 d109 o145 b100000 d116 b1101111 o40 x6b b1100101 b1101100 o141 d105 x62 d101 b1101001 d46 o40 d71 x69 d118 x65 x20 b1111001 o157 b1110101 d32 o141 d32 d102 o154 x61 x67 b100000 o141 d115 b100000 b1100001 d32 x67 o151 x66 d116 b101110 b100000 d32 d102 d108 d97 o147 d123 x31 b1100101 b110100 d98 d102 b111000 d49 b1100001 d54 b110011 x39 o64 o144 o145 d53 x61 b1100010 b1100011 o60 d48 o65 b1100001 x63 b110110 d101 o63 b111001 d97 d51 o70 d55 b1100010 d125 x20 b101110 x20 b1001000 d97 d118 o145 x20 d97 o40 d103 d111 d111 x64 d32 o164 b1101001 x6d o145 x7e'
solution = ' '
text2 = text.split(' ')
for x in text2:
    print x
    if x[0] == 'b':#binary
        solution += chr(int(x[1:],2))
    elif x[0] == 'x':#hexadecimal
        solution += x[1:].decode("hex")
    elif x[0] == 'd':#decimal
        solution += chr(int(x[1:]))
    elif x[0] == 'o':#octal
        solution += chr(int(x[1:],8))

print solution

二进制

压缩包

当二进制转换成文本时，有rar字段，可能为压缩包文件

用脚本进行转换

import binascii
file1 = open('1.txt')
s = file1.read()
file2 = open('1.rar','wb')
s1 = ''

for i in range(0,len(s),8):
    #print (type(int(s[i:i+8],2)))
    if ((int(s[i:i+8],2))<=15):
        print(hex(int(s[i:i+8],2)))
        s1 = s1+'0'+hex(int(s[i:i+8],2)).replace('0x','')
        print (s1)
    else
        s1 += hex(int(s[i:i+8],2)).replace('0x','')
print (s)
file2.write(binascii.a2b_hex(s1))

隐写 IDAT块

当得到一串01的数据时

如果统计长度为625，625开根为25，可以判断为正方形形状

用脚本转换

from PIL import Image
MAX = 25
pic = Image.new('RGB',(MAX,MAX))
str = '1111111000100001101111111100000101110010110100000110111010100000000010111011011101001000000001011101101110101110110100101110110000010101011011010000011111111010101010101111111000000001011101110000000011010011000001010011101101111010101001000011100000000000101000000001001001101000100111001111011100111100001110111110001100101000110011100001010100011010001111010110000010100010110000011011101100100001110011100100001011111110100000000110101001000111101111111011100001101011011100000100001100110001111010111010001101001111100001011101011000111010011100101110100100111011011000110000010110001101000110001111111011010110111011011'
i=0
for y in range (0,MAX):
    for x in range (0,MAX):
        if (str[i] == '1'):
            pic.putpixel([x,y],(0,0,0))
        else:
            pic.putpixel([x,y],(255,255,255))
        i = i + 1
pic.save('flag.png')

二进制转文本

在线转换二进制到字符串 (txttool.com)

BASE编码

BASE64、BASE58、BASE32、BASE16

BASE64

64个可打印字符，A~Z、a~z、0~9、+、/，64个可打印字符，“=”符号用作后缀填充

BASE58

相比Base64，Base58不使用数字”0″，字母大写”O”，字母大写”I”，和字母小写”l”，以及”+”和”/”符号。

BASE32

32个可打印字符，A~Z、2~7、32个可打印字符，“=”符号用作后缀填充

BASE16

16个可打印字符，A~F、0-9，16个可打印字符

BASE	内容(flag)
BASE64	ZmxhZw==
BASE58	3cr9Ae
BASE32	MZWGCZY=
BASE16	666C6167

BASE64异或

import base64

char = 'AAoHAR1UIFBSJFFQU1AjUVEjVidWUVJVJVZUIyUnI18jVFNXVRs='
char = base64.b64decode(char)

for j in range(128):
    flag = ''
    for i in char:
        flag += chr(ord(i) ^ j)
    if 'flag' in flag:
        print(flag)

BASE家族

import base64

a = ' '
 while 1:
     try:
         a = base64.b16decode(a)
    except:
        try:
            a = base64.b32decode(a)
        except:
            try:
                a = base64.b64decode(a)
            except:
                print (a)
                break