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DES_Encrypt.m
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DES_Encrypt.m
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%----------------------------- 主函数 -----------------------------%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [data_encrypt,data_length] = DES_Encrypt(r,key1)
global irt endrt ert iprt pt
irt = ... % 明文初始置换表
[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];
endrt = ... % 明文逆置换表
[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];
ert = ... % 明文扩展置换表
[32 1 2 3 4 5 4 5 ...
6 7 8 9 8 9 10 11 ...
12 13 12 13 14 15 16 17 ...
16 17 18 19 20 21 20 21 ...
22 23 24 25 24 25 26 27 ...
28 29 28 29 30 31 32 1];
iprt = ... % 密钥初始置换表
[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];
pt = ... % P置换表
[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];
data = r; % 提取需要加密的数据
data_length = length(data); % 求取字符长度
adds = 64-mod(data_length,64); % 求取需要补充的字符数
if adds ~= 0
for i = 1:adds
data(data_length+i) = 0; % 不足64位的分组数据后面补零
end
data_length1 = data_length+adds; % 补零后的位数
end
temp = data;
data = [];
for i = 1:data_length1
data = [data,dec2bin(temp(i))];
end
key = key1;
keylength = length(key);
keytemp0 = uint8(key);
keys = [149 57 208 147 21 183 27];
if keylength < 7 % 延长小于七位的密钥
for i = keylength+1:7
keytemp0(i) = keys(i);
end
end
for i=1:7 % 缩短大于七位的密钥
keyusetemp(i) = keytemp0(i);
end
keyuse = char(keyusetemp); % 将密钥转换字符型数据
pwb = str2bin(keyuse,7,2); % 密钥转二进制,并加入偶校验位
pwb = rebit(pwb,iprt); % 密钥初始置换
ki = gerkey(pwb); % 计算16轮子密钥
times = data_length1/64; % 分组加密的组数
for i = 0:times-1
for j = 1:64
tempdata(j) = data(64*i+j); % 提取第i组数据
end
encrydata = des(tempdata,ki); % 调用des函数利用密钥ki对tempdata加密
data_encrypt(i*64+1:(i+1)*64) = encrydata; % 加密后的二进制数据（字符串格式）
end
temp = data_encrypt;
data_encrypt = zeros(size(temp)); % 加密后的二进制数据（双精度格式）
for i = 1:length(data_encrypt)
if temp(i) == '1'
data_encrypt(i) = 1;
else
data_encrypt(i) = 0;
end
end
function bin = str2bin(str,k,flag)
l = length(str);
bin = [];
temp = [];
for x = 1:l
temp = [temp,dec2bin(str(x),8)]; % 将字符串转换为二进制串
end
if flag ~= 0 % 判断是否需要加奇偶校验位
n = ceil(l*8/k); % 校验位总位数
rb = mod(l*8,k);
sb = 0;
if rb ~= 0
sb = k-rb; % 算出当二进制串做奇偶校验位时，在串尾补零的个数
for i = 1:sb
z(i) = '0';
end
temp = [temp z];
end
for x = 0:n-1
temp1 = temp(x*k+1:(x+1)*k);
lone = length(find(temp1 == '1')); % 求k位二进制串中1的个数
if flag == 1 % 计算奇校验位值
if mod(lone,2) == 0
opb = '1';
else
opb = '0';
end
else if flag == 2 % 计算偶校验位值
if mod(lone,2) == 0
opb = '0';
else
opb = '1';
end
end
end
temp1 = [temp1 opb]; % 添加校验位
bin = [bin temp1];
end
else
bin = temp;
end
function so = rebit(si,k)
lk=length(k);
for i=1:lk
so(i)=si(k(i));
end
function ki=gerkey(k)
mt = ... % 移位表（第一行为轮数，第二行为第一行对应轮数左移的位数）
[1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16;
1 1 2 2 2 2 2 2 1 2 2 2 2 2 2 1];
rt = ... % 56位到48位压缩置换表
[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];
kl = k(1:28); % k的左半部分
kr = k(29:56); % k的右半部分
for i = mt(1,1):mt(1,16) % 进行16轮运算，产生16个子密钥
kl = mr(kl,mt(2,i)); % 根据移位表对k的左部分进行循环左移
kr = mr(kr,mt(2,i)); % 根据移位表对k的右部分进行循环左移
k = [kl kr]; % 进左移运算后的k
for j = 1:48 % 根据压缩置换表产生子密钥
ki(i,j) = k(fix(rt(j)));
end
end
function nk = mr(k,n)
l = length(k);
k1 = k(n+1:l);
k2 = k(1:n);
nk = [k1 k2];
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%---------------- 子函数des -----------------%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function ef = des(pf,ki)
global irt endrt ert iprt pt
pfb = rebit(pf,irt); % 明文初始置换
lpfb = pfb(1:32); % 明文左32位
rpfb = pfb(33:64); % 明文右32位
for i = 0:15
templ = lpfb;
lpfb = rpfb; % 下一轮新的左数据输入
tempr = rebit(rpfb,ert); % rpfb扩展置换成48位
rpfb = char(xor(ki(i+1,:)-48,tempr-48)+48); % 48位rpfb与48位子密钥ki(i+1,:)进行异或
rpfb = sbox(rpfb); % S盒置换
rpfb = rebit(rpfb,pt); % P置换
rpfb = char(xor(templ-48,rpfb-48)+48); % 32位templ与32位rpfb进行异或
end
pfb = [rpfb lpfb];
pfb = rebit(pfb,endrt); % 末置换处理
ef = pfb;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%---------------- 子函数sbox ----------------%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function so = sbox(si)
%功能：模拟si通过s盒处理
%输入: si 一维向量 48位长
%输出: so 一维向量 32位长
sbox1 = ... % S1盒
[14 4 13 1 2 15 11 8 3 10 6 12 5 9 0 7;
0 15 7 4 14 2 13 1 10 6 12 11 9 5 3 8;
4 1 14 8 13 6 2 11 15 12 9 7 3 10 5 0;
15 12 8 2 4 9 1 7 5 11 3 14 10 0 6 13];
sbox2 = ... % S2盒
[15 1 8 14 6 11 3 4 9 7 2 13 12 0 5 10;
3 13 4 7 15 2 8 14 12 0 1 10 6 9 11 5;
0 14 7 11 10 4 13 1 5 8 12 6 9 3 2 15;
13 8 10 1 3 15 4 2 11 6 7 12 0 5 14 9];
sbox3 = ... % S3盒
[10 0 9 14 6 3 15 5 1 13 12 7 11 4 2 8;
13 7 0 9 3 4 6 10 2 8 5 14 12 11 5 1;
13 6 4 9 8 15 3 0 11 1 2 12 5 10 14 7;
1 10 13 0 6 9 8 7 4 15 14 3 11 5 2 12];
sbox4 = ... % S4盒
[ 7 13 14 3 0 6 9 10 1 2 8 5 11 12 4 15;
13 8 11 5 6 5 0 3 4 7 2 12 1 10 14 9;
10 6 9 0 12 11 7 13 15 1 3 14 5 2 8 4;
3 15 0 6 10 1 13 8 9 4 5 11 12 7 2 14];
sbox5 = ... % S5盒
[ 2 12 4 1 7 10 11 6 8 5 3 15 13 0 14 9;
14 11 2 12 4 7 13 1 5 0 15 10 3 9 8 6;
4 2 1 11 10 13 7 8 15 9 12 5 6 3 0 14;
1 8 12 7 1 14 2 13 6 15 0 9 10 4 5 3];
sbox6 = ... % S6盒
[12 1 10 15 9 2 6 8 0 13 3 4 14 7 5 11;
10 15 4 2 7 12 9 5 6 1 13 14 0 11 3 8;
9 14 15 5 2 8 12 3 7 0 4 10 1 13 11 6;
4 3 2 12 9 5 15 10 11 14 1 7 6 0 8 13];
sbox7 = ... % S7盒
[ 4 11 2 14 15 0 8 13 3 12 9 7 5 10 6 1;
13 0 11 7 4 9 1 10 14 3 5 12 2 15 8 6;
1 4 11 13 12 3 7 14 10 15 6 8 0 5 9 2;
6 11 13 8 1 4 10 7 9 5 0 15 14 2 3 12];
sbox8 = ... % S8盒
[13 2 8 4 6 15 11 1 10 9 3 14 5 0 12 7;
1 15 13 8 10 3 7 4 12 5 6 11 0 14 9 2;
7 11 4 1 9 12 14 2 0 6 10 13 15 3 5 8;
2 1 14 7 4 10 8 13 15 12 9 0 3 5 6 11];
sbox = [sbox1 sbox2 sbox3 sbox4 sbox5 sbox6 sbox7 sbox8];
sboxout = [ ];
for i = 0:7
sboxin(i+1,1:6) = si(i*6+1:(i+1)*6); % 第i+1个s盒输入,盒号从零开始计数
rind = bin2dec([sboxin(i+1,1),sboxin(i+1,6)])+1; % 行号
nind = bin2dec(sboxin(i+1,2:5))+1+i*16; % 列号
sboxout = [sboxout dec2bin(sbox(rind,nind),4)]; % 根据行列号计算出第i+1个s盒的输出
end
so = sboxout;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%