共享一下迅雷P2P通信的加密算法,方便那些研究迅雷P2P通信協(xié)議的同學(xué)們:)
算法細(xì)節(jié)不詳細(xì)描述了,共享算法代碼,只有python版,解密出來的結(jié)果就是
明文協(xié)議了,接下來的事情就是做協(xié)議分析了。發(fā)一個協(xié)議通信的片斷。
192.168.1.103 port 10047 ---> 111.195.202.215 port 10527
0000 32 00 00 00 05 10 00 00 00 30 30 32 32 46 42 38 2........0022FB8
0010 33 41 41 41 34 38 4e 51 51 00 00 3b b4 3AAA48NQQ..;.
111.195.202.215 port 10527 ---> 192.168.1.103 port 10047
0000 32 00 00 00 06 00 00 00 00 3b b4 00 00 61 6a 00 2........;...aj.
0010 02 25 e2 60 24 00 00 00 00 00 00 01 00 00 00 .%.`$..........
192.168.1.103 port 10047 ---> 111.195.202.215 port 10527
0000 32 00 00 00 06 01 00 00 00 00 00 3b b4 61 57 e1 2..........;.aW.
0010 03 63 e1 7a 03 26 e2 60 24 00 00 05 00 00 00 .c.z.&.`$......
111.195.202.215 port 10527 ---> 192.168.1.103 port 10047
0000 32 00 00 00 11 3b b4 00 00 61 6a 00 02 00 00 01 2....;...aj.....
0010 00 26 e2 60 24 64 e1 7a 03 63 e1 7a 03 01 00 00 .&.`$d.z.c.z....
0020 00 00 00 00 00 .....
算法如下
#Created by vessial
def p2p_udp_encrypt(pkt):
header=random.randint(0,0xffff)
t=((header&0x1fff)+0x4000)<<0x10
t+=random.randint(0,0xffff)
body=struct.pack('I',t)
sec2=random.randint(0,0xff)
body+=struct.pack('B',sec2)
length=(sec2&0x03)+9
pos=length
for i in range(length-5):
x=random.randint(0,0xff)
body+=struct.pack('B',x)
l=pos*7
t=struct.unpack('B',body[pos-3])[0]
t*=0x0d
t&=0xff
k=l^t
header=body[:pos-2]+struct.pack('B',k)
t=struct.unpack('B',header[-1])[0]
t*=0x0d
t&=0xff
k=(l+7)^t
header=header+struct.pack('B',k)
out=''
j=0
t=array.array('B',header)
buf=array.array('B',pkt)
body_len=len(pkt)
for i in range(body_len):
j+=1
if j==pos:
j=0
x=t[j]+0x5b
x&=0xff
x^=t[j-1]
t[j-1]=x
buf[i]=(buf[i]+x)&0xff
out=header+buf.tostring()
#print "out buf len is %d"%len(out)
#print hexdump(out)
#print hexdump(p2p_udp_decrypt(out))
return out
def p2p_udp_decrypt(pkt):
if len(pkt)<=8:
return False
header=struct.unpack('<I',pkt[:4])[0]
header>>=0x1d
if header>3:
return False
elif header ==1:
pass
elif header ==2:
byte5=struct.unpack('B',pkt[4])[0]
byte5&=0x80000003
byte5+=9
if byte5>len(pkt):
return False
pos=byte5
head_check=array.array('B',pkt[:pos])
t=struct.unpack('B',pkt[pos-2])[0]
mid=pos*7
p=7*pos+7
t*=0x0d
t&=0xff
p^=t
s=struct.unpack('B',pkt[pos-1])[0]
if p != s:
return False
t=struct.unpack('B',pkt[pos-3])[0]
t*=0x0d
t&=0xff
t^=mid
if t !=struct.unpack('B',pkt[pos-2])[0]:
return False
j=0
body=array.array('B',pkt[pos:])
body_len=len(pkt)-pos
for i in range(body_len):
j+=1
if j==pos:
j=0
x=head_check[j]+0x5b
x&=0xff
x^=head_check[j-1]
head_check[j-1]=x
body[i]=(body[i]-x)&0xff
x=body.tostring()
#print hexdump(x)
return x
elif header ==3:
pass
return False