matlab实现md5算法,md5算法详解,matlab

function output_str = MD5(orign_str) % orign_str 待hash的原始字符串 % output_str md5算法输出的结果 % 设置标准向量，注意内存的大小端存储 a = '67452301'; b = 'efcdab89'; c = '98badcfe'; d = '10325476'; % 将标准向量转化为二进制串表示, for i = 1:8 a_dec(i) = hex2dec(a(i)); a_bin(i,:) = dec2bin(a_dec(i),4); b_dec(i) = hex2dec(b(i)); b_bin(i,:) = dec2bin(b_dec(i),4); c_dec(i) = hex2dec(c(i)); c_bin(i,:) = dec2bin(c_dec(i),4); d_dec(i) = hex2dec(d(i)); d_bin(i,:) = dec2bin(d_dec(i),4); end % 将原来8x4的矩阵转换为1x32的矩阵，方便后续运算 A = reshape(a_bin',1,32); B = reshape(b_bin',1,32); C = reshape(c_bin',1,32); D = reshape(d_bin',1,32); % 将转换好的向量作为初始向量进行初始化 AA = A; BB = B; CC = C; DD = D; % 将输入的字符串转换为对应的ascii码值矩阵 str_len = length(orign_str); input_ascii = abs(orign_str); % 确定分组个数，512位为一组，一组为64字节，最后需要64位（8字节）存储原字符串的长度 group = ceil((str_len+8)/64); % 对分组个数向上取整，不足一组的按一组记 % 对原始数据进行填充 for k = 1:group*64 if k<=str_len % 将字符串码值放到前面 input_ascii_1(k) = input_ascii(k); elseif k==str_len+1 % 字符串结束之后，从二进制上看需要在字符串结束之后第一位用1，之后用0进行填充 % 形如1000 0000 转换为十进制就是128， input_ascii_1(k) = 128; elseif k==group*64-7 % 倒数第8个字节存放二进制长度模256的余数 input_ascii_1(k) = mod(str_len*8,256); elseif k==group*64-6 % 倒数第7个字节存放二进制长度被256除的商，利用商和余数可以还原出原始长度。 input_ascii_1(k) = str_len*8/256; else % 其余位置用0填充 input_ascii_1(k) = 0; end end % 对每个分组依次进行计算 for g = 1:group k = 1; % 调整数据的顺序与结构 for i = 1:16 for j = 4:-1:1 input_change(i,j) = input_ascii_1(64*(g-1)+k); k = k + 1; end end input = reshape(dec2bin(input_change',8)',32,16)'; % disp(input); % 利用正弦值生成后续操作中所需的常量 for i = 1:64 T(i,:) = dec2bin(floor(2^32*abs(sin(i))),32); end M = input; % 对输入作4轮共64次计算 A = FF(A,B,C,D,M,7,T,1,1); D = FF(D,A,B,C,M,12,T,2,2); C = FF(C,D,A,B,M,17,T,3,3); B = FF(B,C,D,A,M,22,T,4,4); A = FF(A,B,C,D,M,7,T,5,5); D = FF(D,A,B,C,M,12,T,6,6); C = FF(C,D,A,B,M,17,T,7,7); B = FF(B,C,D,A,M,22,T,8,8); A = FF(A,B,C,D,M,7,T,9,9); D = FF(D,A,B,C,M,12,T,10,10); C = FF(C,D,A,B,M,17,T,11,11); B = FF(B,C,D,A,M,22,T,12,12); A = FF(A,B,C,D,M,7,T,13,13); D = FF(D,A,B,C,M,12,T,14,14); C = FF(C,D,A,B,M,17,T,15,15); B = FF(B,C,D,A,M,22,T,16,16); A = GG(A,B,C,D,M,5,T,2,17); D = GG(D,A,B,C,M,9,T,7,18); C = GG(C,D,A,B,M,14,T,12,19); B = GG(B,C,D,A,M,20,T,1,20); A = GG(A,B,C,D,M,5,T,6,21); D = GG(D,A,B,C,M,9,T,11,22); C = GG(C,D,A,B,M,14,T,16,23); B = GG(B,C,D,A,M,20,T,5,24); A = GG(A,B,C,D,M,5,T,10,25); D = GG(D,A,B,C,M,9,T,15,26); C = GG(C,D,A,B,M,14,T,4,27); B = GG(B,C,D,A,M,20,T,9,28); A = GG(A,B,C,D,M,5,T,14,29); D = GG(D,A,B,C,M,9,T,3,30); C = GG(C,D,A,B,M,14,T,8,31); B = GG(B,C,D,A,M,20,T,13,32); A = HH(A,B,C,D,M,4,T,6,33); D = HH(D,A,B,C,M,11,T,9,34); C = HH(C,D,A,B,M,16,T,12,35); B = HH(B,C,D,A,M,23,T,15,36); A = HH(A,B,C,D,M,4,T,2,37); D = HH(D,A,B,C,M,11,T,5,38); C = HH(C,D,A,B,M,16,T,8,39); B = HH(B,C,D,A,M,23,T,11,40); A = HH(A,B,C,D,M,4,T,14,41); D = HH(D,A,B,C,M,11,T,1,42); C = HH(C,D,A,B,M,16,T,4,43); B = HH(B,C,D,A,M,23,T,7,44); A = HH(A,B,C,D,M,4,T,10,45); D = HH(D,A,B,C,M,11,T,13,46); C = HH(C,D,A,B,M,16,T,16,47); B = HH(B,C,D,A,M,23,T,3,48); A = II(A,B,C,D,M,6,T,1,49); D = II(D,A,B,C,M,10,T,8,50); C = II(C,D,A,B,M,15,T,15,51); B = II(B,C,D,A,M,21,T,6,52); A = II(A,B,C,D,M,6,T,13,53); D = II(D,A,B,C,M,10,T,4,54); C = II(C,D,A,B,M,15,T,11,55); B = II(B,C,D,A,M,21,T,2,56); A = II(A,B,C,D,M,6,T,9,57); D = II(D,A,B,C,M,10,T,16,58); C = II(C,D,A,B,M,15,T,7,59); B = II(B,C,D,A,M,21,T,14,60); A = II(A,B,C,D,M,6,T,5,61); D = II(D,A,B,C,M,10,T,12,62); C = II(C,D,A,B,M,15,T,3,63); B = II(B,C,D,A,M,21,T,10,64); % 将四轮运算之后的结果与初始的标准向量做模加运算 A_dec = bin2dec(A); B_dec = bin2dec(B); C_dec = bin2dec(C); D_dec = bin2dec(D); AA_dec = bin2dec(AA); BB_dec = bin2dec(BB); CC_dec = bin2dec(CC); DD_dec = bin2dec(DD); A_dec = mod((A_dec + AA_dec),2^32); B_dec = mod((B_dec + BB_dec),2^32); C_dec = mod((C_dec + CC_dec),2^32); D_dec = mod((D_dec + DD_dec),2^32); if g==group % 如果是最后一组就将四组值做级联，并调整合适的形式进行输出 output_str = dec2hex([A_dec;B_dec;C_dec;D_dec],8); % 考虑内存大小端存储的不同 output_str = output_str(:,[7 8 5 6 3 4 1 2])'; output_str = output_str(:)'; else % 如果不是最后一组，就将上一组的结果作为下一组的初始值带入运算 A = dec2bin(A_dec,32); B = dec2bin(B_dec,32); C = dec2bin(C_dec,32); D = dec2bin(D_dec,32); AA = A; BB = B; CC = C; DD = D; end end end