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参考网络资源用PYTHON把DES的流程走了一遍，以下为代码与解析,更为具体的细节可参照http://orlingrabbe.com/des.htm或*
假设要加密的原文为a406753854abcdef密钥为a34457799bbcdff1（16进制）
s = 'a406753854abcdef' key = 'a34457799bbcdff1'
第一步 密钥的生成
1.将原文转为2进制
__hex_bin = {
'0':'0000','1':'0001','2':'0010','3':'0011',
'4':'0100','5':'0101','6':'0110','7':'0111',
'8':'1000','9':'1001','a':'1010','b':'1011',
'c':'1100','d':'1101','e':'1110','f':'1111',
' ':'0000'
}
key = ''.join(__hex_bin[i] for i in key)
2.P-1重新排列
排列矩阵为P1
__re = lambda t, s: ''.join(s[i-1] for i in t)
# PC-1
__k1 = [
57,49,41,33,25,17, 9,
1 ,58,50,42,34,26,18,
10, 2,59,51,43,35,27,
19,11, 3,60,52,44,36,
63,55,47,39,31,23,15,
7 ,62,54,46,38,30,22,
14, 6,61,53,45,37,29,
21,13, 5,28,20,12, 4,
]
密钥由64位变为56位
3.将其分为左右两组C0与D0,分别按照循环移位表移位，得到Cn Dn
移位表：
序数 左移位数
1 1
2 1
3 2
4 2
5 2
6 2
7 2
8 2
9 1
10 2
11 2
12 2
13 2
14 2
15 2
16 1
代码：
k0 = [
0,1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28,
]
key = [key[k0[i]:28]+key[0:k0[i]] + key[k0[i]+28:56]+key[28:k0[i]+28] for i in range(17)]
4再次重排列
#PC-2 __k2 = [ 14,17,11,24, 1, 5, 3,28, 15, 6,21,10,23,19,12, 4, 26, 8,16, 7,27,20,13, 2, 41,52,31,37,47,55,30,40, 51,45,33,48,44,49,39,56, 34,53,46,42,50,36,29,32, ] key = [__re(__k2,key[i]) for i in range(1,17)]
运行结果：
key a34457799bbcdff1 K 1010001101000100010101110111100110011011101111001101111111110001 K+ 11110001110011101010100111110101010101100110011110001100 n Cn Dn 0 1111000111001110101010011111 0101010101100110011110001100 1 1110001110011101010100111111 1010101011001100111100011000 2 1100011100111010101001111111 0101010110011001111000110001 3 0001110011101010100111111111 0101011001100111100011000101 4 0111001110101010011111111100 0101100110011110001100010101 5 1100111010101001111111110001 0110011001111000110001010101 6 0011101010100111111111000111 1001100111100011000101010101 7 1110101010011111111100011100 0110011110001100010101010110 8 1010101001111111110001110011 1001111000110001010101011001 9 0101010011111111100011100111 0011110001100010101010110011 10 0101001111111110001110011101 1111000110001010101011001100 11 0100111111111000111001110101 1100011000101010101100110011 12 0011111111100011100111010101 0001100010101010110011001111 13 1111111110001110011101010100 0110001010101011001100111100 14 1111111000111001110101010011 1000101010101100110011110001 15 1111100011100111010101001111 0010101010110011001111000110 16 1111000111001110101010011111 0101010101100110011110001100 K 1 100110110000101011111111111110000111000001110010 K 2 011110011100111011011011110110111100100110100101 K 3 011101011111100110001110000000100100111110011001 K 4 001100101010110111010111110110110011000100010101 K 5 011111010110110000110111111000110100001110101000 K 6 111001111010010110111100010100000011101100001111 K 7 110111101000011010110111111101100001000010111100 K 8 111111111001101000111010010000010011101111101011 K 9 111000011111101110101011011011001110011110000001 K 10 101100011011011111010111101110100100010001001111 K 11 011101010101111011010011110011101101001110000010 K 12 011101111111000111110100100101000110011101101001 K 13 100111101100010111010111111110101001101001000000 K 14 011111110100001100111111110100001110011100111010 K 15 101011111001000110101101001111010011111000001000 K 16 110110111011010111001011000010100001011011110101
第二步 加密
1、同样转2进制
s = ''.join(__hex_bin[i] for i in s)2、重排列 排列矩阵为IP
__ip = [ 58,50,42,34,26,18,10,2,60,52,44,36,28,20,12,4, 62,54,46,38,30,22,14,6,64,56,48,40,32,24,16,8, 57,49,41,33,25,17, 9,1,59,51,43,35,27,19,11,3, 61,53,45,37,29,21,13,5,63,55,47,39,31,23,15,7, ] s = __re(__ip,s)
3 F函数（在下一步用到）
F函数对于两个输入R和K
先对R根据E矩阵重排列得到E，再对E、K异或操作，再进行S-BOX
每六位进行一个S-BOX运算，首位与末位合做行标，中间四位做列标
最后仍有一个重新排列P
__p = [
16, 7,20,21,29,12,28,17,
1 ,15,23,26, 5,18,31,10,
2 ,8 ,24,14,32,27, 3, 9,
19,13,30, 6,22,11, 4,25,
]
def __f(r,k):
#E
r = __re(__e,r)
#K+E
r = ''.join('0' if k[i]==r[i] else '1' for i in range(len(r)))
#sbox lookup row i col j
#first and last bit is i
#middle four is j
r = ''.join(__hex_bin['%x'%__s[i][int(r[i*6]+r[i*6+5],2)*16+int(r[i*6+1:i*6+5],2)]] for i in range(8))
r = __re(__p,r)
return r其中s-box矩阵为
__s = [
[
0xe,0x4,0xd,0x1,0x2,0xf,0xb,0x8,0x3,0xa,0x6,0xc,0x5,0x9,0x0,0x7,
0x0,0xf,0x7,0x4,0xe,0x2,0xd,0x1,0xa,0x6,0xc,0xb,0x9,0x5,0x3,0x8,
0x4,0x1,0xe,0x8,0xd,0x6,0x2,0xb,0xf,0xc,0x9,0x7,0x3,0xa,0x5,0x0,
0xf,0xc,0x8,0x2,0x4,0x9,0x1,0x7,0x5,0xb,0x3,0xe,0xa,0x0,0x6,0xd,
],
[
0xf,0x1,0x8,0xe,0x6,0xb,0x3,0x4,0x9,0x7,0x2,0xd,0xc,0x0,0x5,0xa,
0x3,0xd,0x4,0x7,0xf,0x2,0x8,0xe,0xc,0x0,0x1,0xa,0x6,0x9,0xb,0x5,
0x0,0xe,0x7,0xb,0xa,0x4,0xd,0x1,0x5,0x8,0xc,0x6,0x9,0x3,0x2,0xf,
0xd,0x8,0xa,0x1,0x3,0xf,0x4,0x2,0xb,0x6,0x7,0xc,0x0,0x5,0xe,0x9,
],
[
0xa,0x0,0x9,0xe,0x6,0x3,0xf,0x5,0x1,0xd,0xc,0x7,0xb,0x4,0x2,0x8,
0xd,0x7,0x0,0x9,0x3,0x4,0x6,0xa,0x2,0x8,0x5,0xe,0xc,0xb,0xf,0x1,
0xd,0x6,0x4,0x9,0x8,0xf,0x3,0x0,0xb,0x1,0x2,0xc,0x5,0xa,0xe,0x7,
0x1,0xa,0xd,0x0,0x6,0x9,0x8,0x7,0x4,0xf,0xe,0x3,0xb,0x5,0x2,0xc,
],
[
0x7,0xd,0xe,0x3,0x0,0x6,0x9,0xa,0x1,0x2,0x8,0x5,0xb,0xc,0x4,0xf,
0xd,0x8,0xb,0x5,0x6,0xf,0x0,0x3,0x4,0x7,0x2,0xc,0x1,0xa,0xe,0x9,
0xa,0x6,0x9,0x0,0xc,0xb,0x7,0xd,0xf,0x1,0x3,0xe,0x5,0x2,0x8,0x4,
0x3,0xf,0x0,0x6,0xa,0x1,0xd,0x8,0x9,0x4,0x5,0xb,0xc,0x7,0x2,0xe,
],
[
0x2,0xc,0x4,0x1,0x7,0xa,0xb,0x6,0x8,0x5,0x3,0xf,0xd,0x0,0xe,0x9,
0xe,0xb,0x2,0xc,0x4,0x7,0xd,0x1,0x5,0x0,0xf,0xa,0x3,0x9,0x8,0x6,
0x4,0x2,0x1,0xb,0xa,0xd,0x7,0x8,0xf,0x9,0xc,0x5,0x6,0x3,0x0,0xe,
0xb,0x8,0xc,0x7,0x1,0xe,0x2,0xd,0x6,0xf,0x0,0x9,0xa,0x4,0x5,0x3,
],
[
0xc,0x1,0xa,0xf,0x9,0x2,0x6,0x8,0x0,0xd,0x3,0x4,0xe,0x7,0x5,0xb,
0xa,0xf,0x4,0x2,0x7,0xc,0x9,0x5,0x6,0x1,0xd,0xe,0x0,0xb,0x3,0x8,
0x9,0xe,0xf,0x5,0x2,0x8,0xc,0x3,0x7,0x0,0x4,0xa,0x1,0xd,0xb,0x6,
0x4,0x3,0x2,0xc,0x9,0x5,0xf,0xa,0xb,0xe,0x1,0x7,0x6,0x0,0x8,0xd,
],
[
0x4,0xb,0x2,0xe,0xf,0x0,0x8,0xd,0x3,0xc,0x9,0x7,0x5,0xa,0x6,0x1,
0xd,0x0,0xb,0x7,0x4,0x9,0x1,0xa,0xe,0x3,0x5,0xc,0x2,0xf,0x8,0x6,
0x1,0x4,0xb,0xd,0xc,0x3,0x7,0xe,0xa,0xf,0x6,0x8,0x0,0x5,0x9,0x2,
0x6,0xb,0xd,0x8,0x1,0x4,0xa,0x7,0x9,0x5,0x0,0xf,0xe,0x2,0x3,0xc,
],
[
0xd,0x2,0x8,0x4,0x6,0xf,0xb,0x1,0xa,0x9,0x3,0xe,0x5,0x0,0xc,0x7,
0x1,0xf,0xd,0x8,0xa,0x3,0x7,0x4,0xc,0x5,0x6,0xb,0x0,0xe,0x9,0x2,
0x7,0xb,0x4,0x1,0x9,0xc,0xe,0x2,0x0,0x6,0xa,0xd,0xf,0x3,0x5,0x8,
0x2,0x1,0xe,0x7,0x4,0xa,0x8,0xd,0xf,0xc,0x9,0x0,0x3,0x5,0x6,0xb,
],
]
4
循环16轮进行以下步骤
Ln = Rn-1
Rn = Ln-1 异或 f(Rn-1,Kn)
f为上述的f函数
for i in range(16):
l_n = r
print '-'*30,'Round',i+1,'-'*30
r_n = __f(r,key[i])
r_n = ''.join('0' if r_n[i]==l[i] else '1' for i in range(len(l)))
print 'r\t',r_n
print 'l\t',l_n
l,r = l_n,r_n
运行结果为
M 1010010000000110011101010011100001010100101010111100110111101111 IP 1101010000011100110101111110010011100001101011011110100010100010 ------------------------------ Round 1 ------------------------------ E 011100000011110101011011111101010001010100000101 K+E 111010110011011110100100000011010110010101110111 S-Box 10100110100010011011010001010000 P 11100011100100000000001111011000 r 00110111100011001101010000111100 l 11100001101011011110100010100010 ------------------------------ Round 2 ------------------------------ E 000110101111110001011001011010101000000111111000 K+E 011000110011001010000010101100010100100001011101 S-Box 01010110001111010111001101101001 P 11101100001101001011110011010110 r 00001101100110010101010001110100 l 00110111100011001101010000111100 ------------------------------ Round 3 ------------------------------ E 000001011011110011110010101010101000001110101000 K+E 011100000100010101111100101010001100110000110001 S-Box 00001000010110001101011010101111 P 00101101001011110000110001101001 r 00011010101000111101100001010101 l 00001101100110010101010001110100 ------------------------------ Round 4 ------------------------------ E 100011110101010100000111111011110000001010101010 K+E 101111011111100011010000001101000011001110111111 S-Box 01110101101000011101111111011011 P 10111011001101101110101100011111 r 10110110101011111011111101101011 l 00011010101000111101100001010101 ------------------------------ Round 5 ------------------------------ E 110110101101010101011111110111111110101101010111 K+E 101001111011100101101000001111001010100011111111 S-Box 01000101110111000001001010111011 P 00101110001000111101110101010001 r 00110100100000000000010100000100 l 10110110101011111011111101101011 ------------------------------ Round 6 ------------------------------ E 000110101001010000000000000000001010100000001000 K+E 111111010011000110111100010100001001001100000111 S-Box 11010000111010000011011110001000 P 00101000101000011010000111001111 r 10011110000011100001111010100100 l 00110100100000000000010100000100 ------------------------------ Round 7 ------------------------------ E 010011111100000001011100000011111101010100001001 K+E 100100010100011011101011111110011100010110110101 S-Box 11100010101100011110010101111001 P 11001111100101001010111110001100 r 11111011000101001010101010001000 l 10011110000011100001111010100100 ------------------------------ Round 8 ------------------------------ E 011111110110100010101001010101010101010001010001 K+E 100000001111001010010011000101000110111110111010 S-Box 01001110001101110010111100100011 P 11010100011010101011110010011100 r 01001010011001001010001000111000 l 11111011000101001010101010001000 ------------------------------ Round 9 ------------------------------ E 001001010100001100001001010100000100000111110000 K+E 110001001011100010100010001111001010011001110001 S-Box 01010010011001100001001000101111 P 01101000011000111001110000100110 r 10010011011101110011011010101110 l 01001010011001001010001000111000 ------------------------------ Round 10 ------------------------------ E 010010100110101110101110100110101101010101011101 K+E 111110111101110001111001001000001001000100010010 S-Box 00001110010011000111011100101001 P 01101000001011010011110011011000 r 00100010010010011001111011100000 l 10010011011101110011011010101110 ------------------------------ Round 11 ------------------------------ E 000100000100001001010011110011111101011100000000 K+E 011001010001110010000000000000010000010010000010 S-Box 10011100000101110010000011000010 P 10000100110110100001000010010011 r 00010111101011010010011000111101 l 00100010010010011001111011100000 ------------------------------ Round 12 ------------------------------ E 100010101111110101011010100100001100000111111010 K+E 111111010000110010101110000001001010011010010011 S-Box 11011001000111011110001010100101 P 10000101101011001101110011100011 r 10100111111001010100001000000011 l 00010111101011010010011000111101 ------------------------------ Round 13 ------------------------------ E 110100001111111100001010101000000100000000000111 K+E 010011100011101011011101010110101101101001000111 S-Box 01101000100111101111111100011000 P 00111111011011001011001111001000 r 00101000110000011001010111110101 l 10100111111001010100001000000011 ------------------------------ Round 14 ------------------------------ E 100101010001011000000011110010101011111110101010 K+E 111010100101010100111100000110100101100010010000 S-Box 10101010110010000001001001001010 P 01101000101110110000001101000000 r 11001111010111100100000101000011 l 00101000110000011001010111110101 ------------------------------ Round 15 ------------------------------ E 111001011110101011111100001000000010101000000111 K+E 010010100111101101010001000111010001010000001111 S-Box 10100001100001001100011000110100 P 00000011101001000101011100101000 r 00101011011001011100001011011101 l 11001111010111100100000101000011 ------------------------------ Round 16 ------------------------------ E 100101010110101100001011111000000101011011111010 K+E 010011101101111011000000111010100100000000001111 S-Box 01100100010101110011111101000100 P 10110100011100011011001010111000 r 01111011001011111111001111111011 l 00101011011001011100001011011101
将第16轮后的L和R合并，进行IP-1的重排列
s = r_n+l_n s = __re(__ip1,s) print ' '*25,'%x'%int(s,2)IP-1排列表为
__ip1 = [
40,8,48,16,56,24,64,32,39,7,47,15,55,23,63,31,
38,6,46,14,54,22,62,30,37,5,45,13,53,21,61,29,
36,4,44,12,52,20,60,28,35,3,43,11,51,19,59,27,
34,2,42,10,50,18,58,26,33,1,41, 9,49,17,57,25,
]
得到最终结果
RL
0111101100101111111100111111101100101011011001011100001011011101
IP-1
1111011111011101001100101101001101000111111101010110111100001111
------------------------------ Hex Form ------------------------------
f7dd32d347f56f0f