所以我为我的大学作业制作了一个简单的 AES 算法。它本身工作正常的算法我没有收到任何错误，密文和解密文本都很好，但是当我尝试访问解密文本时，它会被更改。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include <conio.h>
typedef struct {
int bits[4][4][8];
}Block;
int SBox[16][16] = {
{ 99, 124, 119, 123, 242, 107, 111, 197, 48, 1, 103, 43, 254, 215, 171, 118 },
{ 202, 130, 201, 125, 250, 89, 71, 240, 173, 212, 162, 175, 156, 164, 114, 192 },
{ 183, 253, 147, 38, 54, 63, 247, 204, 52, 165, 229, 241, 113, 216, 49, 21 },
{ 4, 199, 35, 195, 24, 150, 5, 154, 7, 18, 128, 226, 235, 39, 178, 117 },
{ 9, 131, 44, 26, 27, 110, 90, 160, 82, 59, 214, 179, 41, 227, 47, 132 },
{ 83, 209, 0, 237, 32, 252, 177, 91, 106, 203, 190, 57, 74, 76, 88, 207 },
{ 208, 239, 170, 251, 67, 77, 51, 133, 69, 249, 2, 127, 80, 60, 159, 168 },
{ 81, 163, 64, 143, 146, 157, 56, 245, 188, 182, 218, 33, 16, 255, 243, 210 },
{ 205, 12, 19, 236, 95, 151, 68, 23, 196, 167, 126, 61, 100, 93, 25, 115 },
{ 96, 129, 79, 220, 34, 42, 144, 136, 70, 238, 184, 20, 222, 94, 11, 219 },
{ 224, 50, 58, 10, 73, 6, 36, 92, 194, 211, 172, 98, 145, 149, 228, 121 },
{ 231, 200, 55, 109, 141, 213, 78, 169, 108, 86, 244, 234, 101, 122, 174, 8 },
{ 186, 120, 37, 46, 28, 166, 180, 198, 232, 221, 116, 31, 75, 189, 139, 138 },
{ 112, 62, 181, 102, 72, 3, 246, 14, 97, 53, 87, 185, 134, 193, 29, 158 },
{ 225, 248, 152, 17, 105, 217, 142, 148, 155, 30, 135, 233, 206, 85, 40, 223 },
{ 140, 161, 137, 13, 191, 230, 66, 104, 65, 153, 45, 15, 176, 84, 187, 22 }
};
int SBoxInverse[16][16] = {
{ 82, 9, 106, 213, 48, 54, 165, 56, 191, 64, 163, 158, 129, 243, 215, 251},
{ 124, 227, 57, 130, 155, 47, 255, 135, 52, 142, 67, 68, 196, 222, 233, 203},
{ 84, 123, 148, 50, 166, 194, 35, 61, 238, 76, 149, 11, 66, 250, 195, 78},
{ 8, 46, 161, 102, 40, 217, 36, 178, 118, 91, 162, 73, 109, 139, 209, 37},
{ 114, 248, 246, 100, 134, 104, 152, 22, 212, 164, 92, 204, 93, 101, 182, 146},
{ 108, 112, 72, 80, 253, 237, 185, 218, 94, 21, 70, 87, 167, 141, 157, 132},
{ 144, 216, 171, 0, 140, 188, 211, 10, 247, 228, 88, 5, 184, 179, 69, 6},
{ 208, 44, 30, 143, 202, 63, 15, 2, 193, 175, 189, 3, 1, 19, 138, 107},
{ 58, 145, 17, 65, 79, 103, 220, 234, 151, 242, 207, 206, 240, 180, 230, 115},
{ 150, 172, 116, 34, 231, 173, 53, 133, 226, 249, 55, 232, 28, 117, 223, 110},
{ 71, 241, 26, 113, 29, 41, 197, 137, 111, 183, 98, 14, 170, 24, 190, 27},
{ 252, 86, 62, 75, 198, 210, 121, 32, 154, 219, 192, 254, 120, 205, 90, 244},
{ 31, 221, 168, 51, 136, 7, 199, 49, 177, 18, 16, 89, 39, 128, 236, 95},
{ 96, 81, 127, 169, 25, 181, 74, 13, 45, 229, 122, 159, 147, 201, 156, 239},
{ 160, 224, 59, 77, 174, 42, 245, 176, 200, 235, 187, 60, 131, 83, 153, 97},
{ 23, 43, 4, 126, 186, 119, 214, 38, 225, 105, 20, 99, 85, 33, 12, 125}
};
Block getBlock(char pt[],int nthBlock) {
Block block;
char HexToBinary[16][4] = {"0000","0001","0010","0011","0100","0101","0110","0111","1000","1001","1010","1011","1100","1101","1110","1111"};
int index = nthBlock * 32,i,j,h = -1,k;
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
for (k = 0; k < 8; k++) {
if(k % 4 == 0) h++;
char currentChar = index+h < (int)strlen(pt) ? pt[index+h] : '0';
int hex = currentChar - ((currentChar >= '0' && currentChar <= '9') ? '0' : ('A' - 10));
block.bits[j][i][k] = HexToBinary[hex][k % 4] - '0';
}
}
}
return block;
}
Block getKeyBlock(int key[]){
char HexToBinary[16][4] = {"0000","0001","0010","0011","0100","0101","0110","0111","1000","1001","1010","1011","1100","1101","1110","1111"};
Block block;
int i,j,h = 0,k;
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++,h++) {
int v1 = (key[h] >> 4) & 0x0F;
int v2 = key[h] & 0x0F;
for (k = 0; k < 8; k++) block.bits[j][i][k] = HexToBinary[k < 4 ? v1 : v2][k % 4] - '0';
}
}
return block;
}
void printBlockH(Block block,char title[],int n){
int i,j,k;
printf("\n\t%s [%02d] : ",title,n);
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
for (k = 0; k < 8; k++) printf("%d",block.bits[i][j][k]);
printf(" ");
}
}
}
void printBlock(Block block,char title[],int n){
int i,j;
printf("\n%s [%02d] : \n",title,n);
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
int val = block.bits[i][j][0] * 128 + block.bits[i][j][1] * 64 + block.bits[i][j][2] * 32 + block.bits[i][j][3] * 16 + block.bits[i][j][4] * 8 + block.bits[i][j][5] * 4 + block.bits[i][j][6] * 2 + block.bits[i][j][7];
printf("%02x ",val);
}
printf("\n");
}
}
void printColumn(int col[4][8],char title[],int n){
int i;
printf("\n%s [%02d] : \n",title,n);
for (i = 0; i < 4; i++) {
int val = col[i][0] * 128 + col[i][1] * 64 + col[i][2] * 32 + col[i][3] * 16 + col[i][4] * 8 + col[i][5] * 4 + col[i][6] * 2 + col[i][7];
printf("%02x\n",val);
}
}
Block SBoxBlock(Block block){
int i,j,h,k;
Block newBlock = {};
for (i = 0; i < 4; i++){
for (j = 0; j < 4; j++){
k = block.bits[i][j][0] * 8 + block.bits[i][j][1] * 4 + block.bits[i][j][2] * 2 + block.bits[i][j][3];
h = block.bits[i][j][4] * 8 + block.bits[i][j][5] * 4 + block.bits[i][j][6] * 2 + block.bits[i][j][7];
int sBoxResult = SBox[k][h];
for (k = 7; k >= 0; k--) {
newBlock.bits[i][j][k] = sBoxResult & 1;
sBoxResult >>= 1;
}
}
}
return newBlock;
}
Block SBoxBlockInverse(Block block){
int i,j,h,k;
Block newBlock = {};
for (i = 0; i < 4; i++){
for (j = 0; j < 4; j++){
k = block.bits[i][j][0] * 8 + block.bits[i][j][1] * 4 + block.bits[i][j][2] * 2 + block.bits[i][j][3];
h = block.bits[i][j][4] * 8 + block.bits[i][j][5] * 4 + block.bits[i][j][6] * 2 + block.bits[i][j][7];
int sBoxResult = SBoxInverse[k][h];
for (k = 7; k >= 0; k--) {
newBlock.bits[i][j][k] = sBoxResult & 1;
sBoxResult >>= 1;
}
}
}
return newBlock;
}
void SBoxColumn(int c1[4][8],int c2[][8]){
int i,h,k;
for (i = 0; i < 4; i++){
k = c1[i][0] * 8 + c1[i][1] * 4 + c1[i][2] * 2 + c1[i][3];
h = c1[i][4] * 8 + c1[i][5] * 4 + c1[i][6] * 2 + c1[i][7];
int sBoxResult = SBox[k][h];
for (k = 7; k >= 0; k--) {
c2[i][k] = sBoxResult & 1;
sBoxResult >>= 1;
}
}
}
void SBoxColumnInverse(int c1[4][8],int c2[][8]){
int i,h,k;
for (i = 0; i < 4; i++){
k = c1[i][0] * 8 + c1[i][1] * 4 + c1[i][2] * 2 + c1[i][3];
h = c1[i][4] * 8 + c1[i][5] * 4 + c1[i][6] * 2 + c1[i][7];
int sBoxResult = SBoxInverse[k][h];
for (k = 7; k >= 0; k--) {
c2[i][k] = sBoxResult & 1;
sBoxResult >>= 1;
}
}
}
Block ShiftRows(Block block){
Block newBlock = {};
int i,j,k,n = 0;
for (i = 0; i < 4; i++,n++) for (j = 0; j < 4; j++) for (k = 0; k < 8; k++) newBlock.bits[i][j][k] = block.bits[i][(j+n) % 4][k];
return newBlock;
}
Block ShiftRowsInverse(Block block){
Block newBlock = {};
int i,j,k,n = 0;
int indexes[4][4] = {
{0,1,2,3},
{3,0,1,2},
{2,3,0,1},
{1,2,3,0}
};
for (i = 0; i < 4; i++,n++) for (j = 0; j < 4; j++) for (k = 0; k < 8; k++) newBlock.bits[i][j][k] = block.bits[i][indexes[n][j]][k];
return newBlock;
}
void Xor(int a[9],int b[8],int *r){
int i;
for (i = 0; i < 8; i++) r[i] = a[i+1] ^ b[i];
}
void XorColumn(int a[4][8],int b[4][8],int c[][8]){
int i,j;
for(i = 0; i < 4; i++) for(j = 0; j < 8; j++) c[i][j] = a[i][j] ^ b[i][j];
}
int GaloisMult(int a, int b){
int i,j=0,h=0,k,abits[8],bbits[8],rbits[8];
for (i = 0; i < 8; i++){
if(((a >> i) & 1) != 0) abits[j++] = i;
if(((b >> i) & 1) != 0) bbits[h++] = i;
}
int dbits[] = {0,0,0,0,0,0,0,0,0,0,0};
for (k = 0; k < h; k++) for (i = 0; i < j; i++) dbits[10 - abits[i] + bbits[k]] = (dbits[10 - abits[i] + bbits[k]] + 1) % 2;
int val = 0;
for (i = 0; i < 11; i++) val = (val << 1) | dbits[i];
while(val > 0xff) val ^= 0x11b;
return val;
}
Block MixColumn(Block block){
int i,j,k;
int m1[4][4] = {
{2,3,1,1},
{1,2,3,1},
{1,1,2,3},
{3,1,1,2}
};
int m2[4][4];
int result[4][4] = {
{0,0,0,0},
{0,0,0,0},
{0,0,0,0},
{0,0,0,0}
};
for (i = 0; i < 4; i++) for (j = 0; j < 4; j++) m2[i][j] = block.bits[i][j][0] * 128 + block.bits[i][j][1] * 64 + block.bits[i][j][2] * 32 + block.bits[i][j][3] * 16 + block.bits[i][j][4] * 8 + block.bits[i][j][5] * 4 + block.bits[i][j][6] * 2 + block.bits[i][j][7];
for (i = 0; i < 4; i++) for (j = 0; j < 4; j++) for (k = 0; k < 4; k++) result[j][i] ^= GaloisMult(m2[k][i],m1[j][k]);
Block newBlock = {};
for (i = 0; i < 4; i++){
for (j = 0; j < 4; j++){
int val = result[i][j];
for (k = 7; k >= 0; k--) {
newBlock.bits[i][j][k] = val & 1;
val >>= 1;
}
}
}
return newBlock;
}
Block MixColumnInverse(Block block){
int i,j,k;
int m1[4][4] = {
{14,11,13,9},
{9,14,11,13},
{13,9,14,11},
{11,13,9,14},
};
int m2[4][4];
int result[4][4] = {
{0,0,0,0},
{0,0,0,0},
{0,0,0,0},
{0,0,0,0}
};
for (i = 0; i < 4; i++) for (j = 0; j < 4; j++) m2[i][j] = block.bits[i][j][0] * 128 + block.bits[i][j][1] * 64 + block.bits[i][j][2] * 32 + block.bits[i][j][3] * 16 + block.bits[i][j][4] * 8 + block.bits[i][j][5] * 4 + block.bits[i][j][6] * 2 + block.bits[i][j][7];
for (i = 0; i < 4; i++) for (j = 0; j < 4; j++) for (k = 0; k < 4; k++) result[j][i] ^= GaloisMult(m2[k][i],m1[j][k]);
Block newBlock = {};
for (i = 0; i < 4; i++){
for (j = 0; j < 4; j++){
int val = result[i][j];
for (k = 7; k >= 0; k--) {
newBlock.bits[i][j][k] = val & 1;
val >>= 1;
}
}
}
return newBlock;
}
Block AddRoundKey(Block block,Block key){
Block newBlock = {};
int i,j,k;
for (i = 0; i < 4; i++) for (j = 0; j < 4; j++) for (k = 0; k < 8; k++) newBlock.bits[i][j][k] = block.bits[i][j][k] ^ key.bits[i][j][k];
return newBlock;
}
void GetColumn(Block b,int col[][8],int x,int n){
int i,j;
for(i = 0; i < 4; i++) for(j = 0; j < 8; j++) col[i][j] = b.bits[(i+n) % 4][x][j];
}
int ConvertToASCII(int bits[8],int start) {
int i = bits[start] * 8 + bits[start + 1] * 4 + bits[start + 2] * 2 + bits[start + 3];
return i;
}
void BlockToASCII(char *text,Block b) {
char HexToChar[] = "0123456789ABCDEF";
int i,j,h = 0;
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
int c = ConvertToASCII(b.bits[j][i],0);
int c2 = ConvertToASCII(b.bits[j][i],4);
text[h++] = HexToChar[c];
text[h++] = HexToChar[c2];
}
}
text[h] = '\0';
}
char getHexFromChar(unsigned char c,int n){
char HexToChar[] = "0123456789ABCDEF";
return HexToChar[(n == 0) ? c / 16 : (c % 16)];
}
int indexOf(char c){
char HexToChar[] = "0123456789ABCDEF";
int i = 0;
for (i = 0; i < 16; i++) if(c == HexToChar[i]) return i;
return -1;
}
char getCharFromHex(char a,char b){
int s = indexOf(a) * 16 + indexOf(b);
return (char)s;
}
void Encrypt(char* OutText,char InText[],Block key0,Block Ki[10]){
float PlainTextInBlocks = strlen(InText)*4 / 128;
float extraBlock = fmod(strlen(InText)*4 / 128.0f,1.0f) > 0.0f ? 1 : 0;
int BlocksRequired = (int)PlainTextInBlocks + extraBlock;
int i,j;
Block blocks[BlocksRequired];
for(i = 0; i < BlocksRequired; i++) blocks[i] = getBlock(InText,i);
for(i = 0; i < BlocksRequired; i++) printBlock(blocks[i],"Block",i);
for (i = 0; i < BlocksRequired; i++){
Block block = blocks[i];
Block inp = AddRoundKey(block,key0);
// printBlock(inp,"inp",i);
for (j = 0; j < 10; j++){
Block sb = SBoxBlock(inp);
// printBlock(sb,"sb",j);
Block sft = ShiftRows(sb);
// printBlock(sft,"sft",j);
Block mc = MixColumn(sft);
// printBlock(mc,"mx",j);
inp = AddRoundKey((j != 9) ? mc : sft,Ki[j]);
// printBlock(inp,"inp",j);
}
// printBlock(inp,"inp",i);
char text[33];
BlockToASCII(text,inp);
strcat(OutText,text);
}
}
void Decrypt(char* OutText,char InText[],Block key0,Block Ki[10]){
float PlainTextInBlocks = strlen(InText)*4 / 128;
float extraBlock = fmod(strlen(InText)*4 / 128.0f,1.0f) > 0.0f ? 1 : 0;
int BlocksRequired = (int)PlainTextInBlocks + extraBlock;
int i,j;
Block blocks[BlocksRequired];
for(i = 0; i < BlocksRequired; i++) blocks[i] = getBlock(InText,i);
for(i = 0; i < BlocksRequired; i++) printBlock(blocks[i],"Block",i);
for (i = 0; i < BlocksRequired; i++){
Block block = blocks[i];
Block inp = AddRoundKey(block,Ki[9]);
// printBlock(inp,"inp",i);
for (j = 0; j < 10; j++){
Block sft = ShiftRowsInverse(inp);
// printBlock(sft,"sft",j);
Block sb = SBoxBlockInverse(sft);
// printBlock(sb,"sb",j);
// printBlock((j == 9) ? key0 : Ki[8-j],"Ki",j);
Block add = AddRoundKey(sb,(j == 9) ? key0 : Ki[8-j]);
// printBlock(add,"add",j);
inp = (j == 9) ? add : MixColumnInverse(add);
// printBlock(inp,"inp",j);
}
// printBlock(inp,"inp",i);
char text[33];
BlockToASCII(text,inp);
strcat(OutText,text);
}
}
int main() {
srand(time(NULL));
int i = 0,j = 0,n = 0,k = 0,l = 0;
char cipherText[] = "";
char DecryptedText[] = "";
char rawInput[1024];
// int key[16] = {43,126,21,22,40,174,210,166,171,247,21,136,9,207,79,60};
int key[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
puts("Enter Plain Text : ");
gets(rawInput);
n = strlen(rawInput);
// char plaintext[] = "3243F6A8885A308D313198A2E0370734";
// while(n % 16 != 0) n++;
char plaintext[(n * 2) + 1];
for (i = 0; i < n; i++){
plaintext[j++] = getHexFromChar(i < (int)strlen(rawInput) ? rawInput[i] : ' ',0);
plaintext[j++] = getHexFromChar(i < (int)strlen(rawInput) ? rawInput[i] : ' ',1);
}
plaintext[j] = '\0';
// for (i = 0; i < 16; i++) key[i] = rand() % 16;
Block OriginalKey = getKeyBlock(key);
printf("\nRandom Key : ");
for(i = 0; i < 16; i++) printf("%X", key[i]);
printf("\n");
int rtemp[10] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36};
int RCon[10][4][8];
for (i = 0; i < 10; i++) for (j = 0; j < 4; j++) for (k = 0; k < 8; k++) RCon[i][j][k] = (((j == 0) ? rtemp[i] : 0) >> (7-k)) & 1;
Block Ki[10];
Block temp = OriginalKey;
for (i = 0; i < 10; i++){
int c1[4][8],c2[4][8],c3[4][8],out[4][8];
for (l = 0; l < 4; l++){
GetColumn(temp,c1,(l == 0) ? 3 : l-1,(l == 0) ? 1 : 0);
GetColumn(temp,c2,l,0);
if(l == 0){
SBoxColumn(c1,c3);
XorColumn(c2,c3,c1);
for (j = 0; j < 4; j++) for (k = 0; k < 8; k++) c2[j][k] = RCon[i][j][k];
}
XorColumn(c1,c2,out);
for (j = 0; j < 4; j++) for (k = 0; k < 8; k++) temp.bits[j][l][k] = out[j][k];
}
Ki[i] = temp;
}
printBlock(OriginalKey,"KeyInitial",0);
printf("Plain Text In Hex : %s",plaintext);
printf("\n\nEncryption ->");
Encrypt(cipherText,plaintext,OriginalKey,Ki);
printf("\n\nCipher Text In Hex : %s\n",cipherText);
printf("\nDecryption ->");
Decrypt(DecryptedText,cipherText,OriginalKey,Ki);
printf("\n\nDecrypted Text In Hex : %s\n",DecryptedText);
//this is line 473
int len = (int)strlen(DecryptedText);
printf("len size : %d\n",len);
printf("aften len msg : %s\n",DecryptedText);
printf("aften len msg Size : %d\n",(int)strlen(DecryptedText));
char rawOutput[len / 2 + 1];
printf("after raw output msg : %s\n",DecryptedText);
printf("after raw output msg Size : %d\n",(int)strlen(DecryptedText));
for (i = 0,j = 0; i < len / 2; i++){
rawOutput[i] = getCharFromHex(DecryptedText[j],DecryptedText[j+1]);
j += 2;
}
rawOutput[i] = '\0';
printf("\nOriginal Text : %s\n",rawOutput);
return 0;
}
该算法工作正常，直到第 473 行，就在第 472 行之前，我打印了解密的文本，它是十六进制格式的正确文本，但现在从第 473 行开始，我将其转换为 ascii 输出。
问题是在第 473 行之后，解密的文本变得越来越短，并且 ascii 输出出现错误。 输出：
...other outputs
Decrypted Text In Hex : 4A696D6D790000000000000000000000
len size : 32
aften len : 4A696D6D79
aften len Size : 11
after raw output : 4A∟█a
after raw output Size : 5
Original Text : J∩∩∩∩∩∩
第二个问题是在第 212 行，我有一个未使用的 int
rbits[8]您的代码中至少存在以下问题：
GaloisMultdbits[10 - abits[i] + bbits[k]rbitscipherTextDecryptedTextrawInput可能还有更多问题，我没有检查。