DES加密实验报告

《网络安全技术》实验姓名系别实验地点学号年级班实验时间成绩评定教师签字实验项目DES加密解密程序设计与实现实验目的:理解DES加密与解密的程序设计算法思想编写DES加密与解密程序，实现对明文的加密与解密，加深对数据加密与解密的理解，掌握DES加密算法思想，提高网络安全的编程能力。所用软件：TC、VC等其它编程工具实现实验内容：掌握DES算法，编写DES算法。1）初始置换 初始置换在第一轮运算之前执行，对输入分组实施如下表所示的变换。此表应从左向右、从上向下读。例如，初始置换把明文的第58位换到第1位的位置，把第50位换到第2位的位置，把第42位换到第3位的位置，等等。58504234261810260524436282012462544638302214664564840322416857494133251791595143352719113615345372921135635547393123157在将这64位数据分为左右两部分，每部分分别为32位，将左32位留下，将右32位按照下表进行排列32123454567898910111213121314151617161718192021202122232425242526272829282930313212）密钥置换 一开始，由于不考虑每个字节的第8位，DES的密钥由64位减至56位，如下表所示。每个字节第8位可作为奇偶校验位以确保密钥不发生错误。57494133251791585042342618102595143352719113605244366355473931231576254463830221466153453729211352820124接着，56位密钥被分成两部分，每部分28位。然后，根据轮数，这两部分分别循环左移l位或2位。下表给出了每轮移动的位数。轮12345678910111213141516位数1122222212222221在DES的每一轮中，从56位密钥选出以下表中的48位子密钥（SubKey），这些子密钥Ki由下面的方式确定。14171124153281562110231912426816727201324152313747553040514533484449395634534642503629323）S盒置换当产生了48位密钥后就可以和右边32位明文进行异或运算了，得到48位的密文。再经过下论的S盒跌带，其功能是把6bit数据变为4bit数据，每个S盒是一个4行、16列的表。盒中的每一项都是一个4位的数。S盒的6个位输入确定了其对应的输出在哪一行哪一列。下面列出所有的8个S盒。14413121511831061259070157414213110612119538411481362111512973105015128249175113141006131151814611349721312051031347152814120110691150147111041315812693215138101315421167120514921009146315511312711428137093461028514121151136498153011121251014711013069874151431152123713143069101285111241513811565034721211014910690121713151314528431506101389451112721442124171011685315130149141121247131501510398642111101378159125630141812711421361509104535121101592680133414751110154271295611314011389141552812370410113116432129515101114176081364112141508133129751061130117491101435122158614111312371410156805926111381410795015142312713284615111109314501271151381037412561101492711419121420610131535821147410813151290356118假定将S盒的6位的输入标记为b1、b2、b3、b4、b5、b6。则b1和b6组合构成了一个2位的数，从0到3，它对应着表中的一行。从b2到b5构成了一个4位的数，从0到15，对应着表中的一列。 例如，假设第6个S盒的输入（即异或函数的第31位到36位）为110011。第1位和最后一位组合形成了11，它对应着第6个S盒的第三行。中间的4位组合在一起形成了1001，它对应着同一个S盒的第9列。S盒6的第三行第9列处的数是14（记住，行、列的记数均从0开始而不是从1开始），则值1110就代替了110011。4）P盒置换 S盒代替运算后的32位输出依照P盒进行置换。该置换把每输入位映射到输出位，任意一位不能被映射两次，也不能被略去，这个置换叫做直接置换。下表给出了每位移到的位置。16720212912281711523265183110282414322739191330622114255）再次异或运算最后，将P盒置换的结果与最初的64位分组的左半部分异或，然后左、右半部分交换，接着开始另一轮。6）当进行到16论后，最终进行一次末置换，形成密文40848165624643239747155523633138646145422623037545135321612936444125220602835343115119592734242105018582633141949175725实验步骤:usingSystem;usingSystem.Collections.Generic;usingSystem.Windows.Forms;usingSystem.Text;namespacedes{classDes{staticreadonlybyte[]BitIP={57,49,41,33,25,17,9,1,59,51,43,35,27,19,11,3,61,53,45,37,29,21,13,5,63,55,47,39,31,23,15,7,56,48,40,32,24,16,8,0,58,50,42,34,26,18,10,2,60,52,44,36,28,20,12,4,62,54,46,38,30,22,14,6};staticreadonlybyte[]BitCP={39,7,47,15,55,23,63,31,38,6,46,14,54,22,62,30,37,5,45,13,53,21,61,29,36,4,44,12,52,20,60,28,35,3,43,11,51,19,59,27,34,2,42,10,50,18,58,26,33,1,41,9,49,17,57,25,32,0,40,8,48,16,56,24};staticreadonlyint[]BitExp={31,0,1,2,3,4,3,4,5,6,7,8,7,8,9,10,11,12,11,12,13,14,15,16,15,16,17,18,19,20,19,20,21,22,23,24,23,24,25,26,27,28,27,28,29,30,31,0};staticreadonlybyte[]BitPM={15,6,19,20,28,11,27,16,0,14,22,25,4,17,30,9,1,7,23,13,31,26,2,8,18,12,29,5,21,10,3,24};staticreadonlybyte[,]sBox={{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},{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},{10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8,13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1,13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7,1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12},{7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15,13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9,10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4,3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14},{2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9,14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6,4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14,11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3},{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},{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},{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}};staticreadonlybyte[]BitPMC1={56,48,40,32,24,16,8,0,57,49,41,33,25,17,9,1,58,50,42,34,26,18,10,2,59,51,43,35,62,54,46,38,30,22,14,6,61,53,45,37,29,21,13,5,60,52,44,36,28,20,12,4,27,19,11,3};staticreadonlybyte[]BitPMC2={13,16,10,23,0,4,2,27,14,5,20,9,22,18,11,3,25,7,15,6,26,19,12,1,40,51,30,36,46,54,29,39,50,44,32,47,43,48,38,55,33,52,45,41,49,35,28,31};enumTDesMode{dmEncry,dmDecry};byte[][]SubKey;publicDes(){SubKey=newbyte[16][];for(inti=0;i<SubKey.Length;i++){SubKey[i]=newbyte[6];}}voidinitPermutation(byte[]inData){byte[]newData=newbyte[8];for(inti=0;i<64;i++){if((inData[BitIP[i]>>3]&(1<<(7-(BitIP[i]&0x07))))!=0){newData[i>>3]|=(byte)(1<<(7-(i&0x07)));}}Array.Copy(newData,inData,8);}voidconversePermutation(byte[]inData){byte[]newData=newbyte[8];for(inti=0;i<64;i++){if((inData[BitCP[i]>>3]&(1<<(7-(BitCP[i]&0x07))))!=0){newData[i>>3]|=(byte)(1<<(7-(i&0x07)));}}Array.Copy(newData,inData,8);}voidexpand(byte[]inData,byte[]outData){Array.Clear(outData,0,6);for(inti=0;i<48;i++){if((inData[BitExp[i]>>3]&(1<<(7-(BitExp[i]&0x07))))!=0){outData[i>>3]|=(byte)(1<<(7-(i&0x07)));}}}voidpermutation(byte[]inData){byte[]newData=newbyte[4];for(inti=0;i<32;i++){if((inData[BitPM[i]>>3]&(1<<(7-(BitPM[i]&0x07))))!=0){newData[i>>3]|=(byte)(1<<(7-(i&0x07)));}}Array.Copy(newData,inData,4);}bytesi(bytes,byteinByte){intc=(inByte&0x20)|((inByte&0x1e)>>1)|((inByte&0x01)<<4);return(byte)(sBox[s,c]&0x0f);}voidpermutationChoose1(byte[]inData,byte[]outData){Array.Clear(outData,0,7);for(inti=0;i<56;i++){if((inData[BitPMC1[i]>>3]&(1<<(7-(BitPMC1[i]&0x07))))!=0){outData[i>>3]|=(byte)(1<<(7-(i&0x07)));}}}voidpermutationChoose2(byte[]inData,byte[]outData){Array.Clear(outData,0,6);for(inti=0;i<48;i++){if((inData[BitPMC2[i]>>3]&(1<<(7-(BitPMC2[i]&0x07))))!=0){outData[i>>3]|=(byte)(1<<(7-(i&0x07)));}}}voidcycleMove(byte[]inData,bytebitMove){for(inti=0;i<bitMove;i++){inData[0]=(byte)((inData[0]<<1)|(inData[1]>>7));inData[1]=(byte)((inData[1]<<1)|(inData[2]>>7));inData[2]=(byte)((inData[2]<<1)|(inData[3]>>7));inData[3]=(byte)((inData[3]<<1)|((inData[0]&0x10)>>4));inData[0]=(byte)(inData[0]&0x0f);}}staticreadonlybyte[]bitDisplace={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};voidmakeKey(byte[]inKey,byte[][]outKey){byte[]outData56=newbyte[7];byte[]key28l=newbyte[4];byte[]key28r=newbyte[4];byte[]key56o=newbyte[7];permutationChoose1(inKey,outData56);key28l[0]=(byte)(outData56[0]>>4);key28l[1]=(byte)((outData56[0]<<4)|(outData56[1]>>4));key28l[2]=(byte)((outData56[1]<<4)|(outData56[2]>>4));key28l[3]=(byte)((outData56[2]<<4)|(outData56[3]>>4));key28r[0]=(byte)(outData56[3]&0x0f);key28r[1]=(byte)(outData56[4]);key28r[2]=(byte)(outData56[5]);key28r[3]=(byte)(outData56[6]);for(inti=0;i<16;i++){cycleMove(key28l,bitDisplace[i]);cycleMove(key28r,bitDisplace[i]);key56o[0]=(byte)((key28l[0]<<4)|(key28l[1]>>4));key56o[1]=(byte)((key28l[1]<<4)|(key28l[2]>>4));key56o[2]=(byte)((key28l[2]<<4)|(key28l[3]>>4));key56o[3]=(byte)((key28l[3]<<4)|(key28r[0]));key56o[4]=(byte)(key28r[1]);key56o[5]=(byte)(key28r[2]);key56o[6]=(byte)(key28r[3]);permutationChoose2(key56o,outKey[i]);};}voidencry(byte[]inData,byte[]subKey,byte[]outData){byte[]outBuf=newbyte[6];byte[]buf=newbyte[8];expand(inData,outBuf);for(inti=0;i<6;i++)outBuf[i]=(byte)(outBuf[i]^subKey[i]);buf[0]=(byte)(outBuf[0]>>2);buf[1]=(byte)(((outBuf[0]&0x03)<<4)|(outBuf[1]>>4));buf[2]=(byte)(((outBuf[1]&0x0f)<<2)|(outBuf[2]>>6));buf[3]=(byte)(outBuf[2]&0x3f);buf[4]=(byte)(outBuf[3]>>2);buf[5]=(byte)(((outBuf[3]&0x03)<<4)|(outBuf[4]>>4));buf[6]=(byte)(((outBuf[4]&0x0f)<<2)|(outBuf[5]>>6));buf[7]=(byte)(outBuf[5]&0x3f);for(inti=0;i<8;i++)buf[i]=si((byte)i,buf[i]);for(inti=0;i<4;i++)outBuf[i]=(byte)((buf[i*2]<<4)|buf[i*2+1]);permutation(outBuf);for(inti=0;i<4;i++)outData[i]=outBuf[i];}voiddesData(TDesModedesMode,byte[]inData,byte[]outData){inti,j;byte[]temp=newbyte[4];byte[]buf=newbyte[4];for(i=0;i<8;i++)outData[i]=inData[i];initPermutation(outData);if(desMode==TDesMode.dmEncry){for(i=0;i<16;i++){for(j=0;j<4;j++)temp[j]=outData[j];for(j=0;j<4;j++)outData[j]=outData[j+4];encry(outData,SubKey[i],buf);for(j=0;j<4;j++)outData[j+4]=(byte)(temp[j]^buf[j]);};for(j=0;j<4;j++)temp[j]=outData[j+4];for(j=0;j<4;j++)outData[j+4]=outData[j];for(j=0;j<4;j++)outData[j]=temp[j];}elseif(desMode==TDesMode.dmDecry){for(i=15;i>=0;i--){for(j=0;j<4;j++)temp[j]=outData[j];for(j=0;j<4;j++)outData[j]=outData[j+4];encry(outData,SubKey[i],buf);for(j=0;j<4;j++)outData[j+4]=(byte)(temp[j]^buf[j]);};for(j=0;j<4;j++)temp[j]=outData[j+4];for(j=0;j<4;j++)outData[j+4]=outData[j];for(j=0;j<4;j++)outData[j]=temp[j];};conversePermutation(outData);}byte[]Redim(byte[]arr,intnewSize){if(newSize==arr.Length)returnarr;byte[]newArr=newbyte[newSize];Array.Copy(arr,0,newArr,0,Math.Min(arr.Length,newSize));returnnewArr;}publicbyte[]EncryBytes(byte[]inData,byte[]keyByte){byte[]tmpByte=newbyte[8];byte[]outByte=newbyte[8];if((inData.Length>0)&&(inData[inData.Length-1]==0)){}if(inData.Length%8!=0)inData=Redim(inData,(inData.Length+7)/8*8);if(keyByte.Length!=8)keyByte=Redim(keyByte,8);makeKey(keyByte,SubKey);byte[]outData=newbyte[inData.Length];for(inti=0;i<inData.Length/8;i++){for(intj=0;j<8;j++){tmpByte[j]=inData[i*8+j];}desData(TDesMode.dmEncry,tmpByte,outByte);for(intj=0;j<8;j++){outData[i*8+j]=outByte[j];}};returnoutData;}publicbyte[]DecryBytes(byte[]inData,byte[]keyByte){byte[]tmpByte=newbyte[8];byte[]outByt