DES算法實現
概述(團隊項目)
DES是一個分組加密算法，它以64位爲分組對數據加密。同時DES也是一個對稱算法：加密和解密用的是同一個算法。DES是一個包含16個階段的「替換–置換」的分組加密算法，64位的分組明文序列做爲加密算法的輸入，通過16輪加密獲得64位的密文序列。android
算法原理
DES算法主要分爲3部分：加解密運算、f函數的處理、輪子密鑰的生成。算法
輪子密鑰的生成
- 16個子密鑰的生成主要是利用了數據表1中的數表，首先將64位的初始密鑰利用PC1壓縮置換位56位的密鑰，而後將其一分爲二，這裏記爲C0和D0。這裏28位的C0和28位的D0分別根據LET數組相應位置的值進行左移位獲得C1和D1。這是將C1和D1合併根據PC2進行壓縮置換獲得48位的子密鑰，並且注意C1和D1做爲下輪的輸入以用來產生下一個子密鑰。
數據表1
//PC-1
private int[] PC1={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};
//PC-2
private int[] PC2={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};
//Schedule of Left Shifts
private int[] LFT={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
f函數的運算
- 從原理圖中能夠看到，f函數的輸入是明文分組的右半分組記爲R和子密鑰記爲K。32位的R首先要利用數據表2中的E進行E盒擴展變換獲得48位的數據，這裏記爲RE。而後將RE與K進行異或運算並將異或結果利用數據表2中的S_BOX進行S盒替換，獲得48位的運算結果記爲RS。再將RS利用數據表2中的P進行P盒替換，獲得32位的最終結果，記爲RF。到這裏f函數的運算任務就完成了。
數據表2
//E擴展
private int[] E={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};
//P置換
private int[] 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};
private static final int[][][] S_Box = {//S-盒
{// S_Box[1]
{ 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 } },
{ // S_Box[2]
{ 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 } },
{ // S_Box[3]
{ 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 } },
{ // S_Box[4]
{ 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 } },
{ // S_Box[5]
{ 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 } },
{ // S_Box[6]
{ 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 } },
{ // S_Box[7]
{ 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 } },
{ // S_Box[8]
{ 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 } }
};
加解密運算
- 在第一輪中將64位的明文分爲L0和R0,則加密運算以下：
L1=R0R1=L0⊕f(R0,K0),而後按此公式進行16輪的運算。
//初始置換
private int[] 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};
//逆初始置換
private int[] IP_1={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};
代碼實現
package DES算法;
public class DES {
byte[] bytekey;
public DES(String strKey) {
this.bytekey = strKey.getBytes();
}// 聲明常量字節數組
private static final int[] 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 }; // 64
private static final int[] IP_1 = { 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 }; // 64
private static final int[] PC_1 = { 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 }; // 56
private static final int[] PC_2 = { 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 }; // 48
private static final int[] E = { 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 }; // 48
private static final int[] 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 }; // 32
private static final int[][][] S_Box = {//S-盒
{// S_Box[1]
{ 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 } },
{ // S_Box[2]
{ 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 } },
{ // S_Box[3]
{ 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 } },
{ // S_Box[4]
{ 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 } },
{ // S_Box[5]
{ 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 } },
{ // S_Box[6]
{ 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 } },
{ // S_Box[7]
{ 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 } },
{ // S_Box[8]
{ 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 } }
};
private static final int[] LeftMove = { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2,2, 2, 2, 1 };
// 左移位置列表
private byte[] UnitDes(byte[] des_key, byte[] des_data, int flag) {
// 檢測輸入參數格式是否正確，錯誤直接返回空值（null）
if ((des_key.length != 8) || (des_data.length != 8)|| ((flag != 1) && (flag != 0))) {
throw new RuntimeException("Data Format Error !");
}
int flags = flag;// 二進制加密密鑰
int[] keydata = new int[64];// 二進制加密數據
int[] encryptdata = new int[64]; // 加密操做完成後的字節數組
byte[] EncryptCode = new byte[8];// 密鑰初試化成二維數組
int[][] KeyArray = new int[16][48];// 將密鑰字節數組轉換成二進制字節數組
keydata = ReadDataToBirnaryIntArray(des_key);// 將加密數據字節數組轉換成二進制字節數組
encryptdata = ReadDataToBirnaryIntArray(des_data);// 初試化密鑰爲二維密鑰數組
KeyInitialize(keydata, KeyArray); // 執行加密解密操做
EncryptCode = Encrypt(encryptdata, flags, KeyArray);
return EncryptCode;
}// 初試化密鑰數組
private void KeyInitialize(int[] key, int[][] keyarray) {
int i;
int j;
int[] K0 = new int[56];// 特別注意：xxx[IP[i]-1]等相似變換
for (i = 0; i < 56; i++) {
K0[i] = key[PC_1[i] - 1]; // 密鑰進行PC-1變換
}
for (i = 0; i < 16; i++) {
LeftBitMove(K0, LeftMove[i]); // 特別注意：xxx[IP[i]-1]等相似變換
for (j = 0; j < 48; j++) {
keyarray[i][j] = K0[PC_2[j] - 1]; // 生成子密鑰keyarray[i][j]
}
}
} // 執行加密解密操做
private byte[] Encrypt(int[] timeData, int flag, int[][] keyarray) {
int i;
byte[] encrypt = new byte[8];
int flags = flag;
int[] M = new int[64];
int[] MIP_1 = new int[64];
// 特別注意：xxx[IP[i]-1]等相似變換
for (i = 0; i < 64; i++) {
M[i] = timeData[IP[i] - 1]; // 明文IP變換
}
if (flags == 1) { // 加密
for (i = 0; i < 16; i++) {
LoopF(M, i, flags, keyarray);
}
} else if (flags == 0) { // 解密
for (i = 15; i > -1; i--) {
LoopF(M, i, flags, keyarray);
}
}
for (i = 0; i < 64; i++) {
MIP_1[i] = M[IP_1[i] - 1]; // 進行IP-1運算
}
GetEncryptResultOfByteArray(MIP_1, encrypt);// 返回加密數據
return encrypt;
}
private int[] ReadDataToBirnaryIntArray(byte[] intdata) {
int i;
int j;
// 將數據轉換爲二進制數，存儲到數組
int[] IntDa = new int[8];
for (i = 0; i < 8; i++) {
IntDa[i] = intdata[i];
if (IntDa[i] < 0) {
IntDa[i] += 256;
IntDa[i] %= 256;
}
}
int[] IntVa = new int[64];
for (i = 0; i < 8; i++) {
for (j = 0; j < 8; j++) {
IntVa[((i * 8) + 7) - j] = IntDa[i] % 2;
IntDa[i] = IntDa[i] / 2;
}
}
return IntVa;
}
private void LeftBitMove(int[] k, int offset) {
int i;
// 循環移位操做函數
int[] c0 = new int[28];
int[] d0 = new int[28];
int[] c1 = new int[28];
int[] d1 = new int[28];
for (i = 0; i < 28; i++) {
c0[i] = k[i];
d0[i] = k[i + 28];
}
if (offset == 1) {
for (i = 0; i < 27; i++) { // 循環左移一位
c1[i] = c0[i + 1];
d1[i] = d0[i + 1];
}
c1[27] = c0[0];
d1[27] = d0[0];
} else if (offset == 2) {
for (i = 0; i < 26; i++) { // 循環左移兩位
c1[i] = c0[i + 2];
d1[i] = d0[i + 2];
}
c1[26] = c0[0];
d1[26] = d0[0];
c1[27] = c0[1];
d1[27] = d0[1];
}
for (i = 0; i < 28; i++) {
k[i] = c1[i];
k[i + 28] = d1[i];
}
}
private void LoopF(int[] M, int times, int flag, int[][] keyarray) {
int i;
int j;
int[] L0 = new int[32];
int[] R0 = new int[32];
int[] L1 = new int[32];
int[] R1 = new int[32];
int[] RE = new int[48];
int[][] S = new int[8][6];
int[] sBoxData = new int[8];
int[] sValue = new int[32];
int[] RP = new int[32];
for (i = 0; i < 32; i++) {
L0[i] = M[i]; // 明文左側的初始化
R0[i] = M[i + 32]; // 明文右側的初始化
}
for (i = 0; i < 48; i++) {
RE[i] = R0[E[i] - 1]; // 通過E變換擴充，由32位變爲48位
RE[i] = RE[i] + keyarray[times][i]; // 與KeyArray[times][i]按位做不進位加法運算
if (RE[i] == 2) {
RE[i] = 0;
}
}
for (i = 0; i < 8; i++) { // 48位分紅8組
for (j = 0; j < 6; j++) {
S[i][j] = RE[(i * 6) + j];
}
// 下面通過S盒，獲得8個數
sBoxData[i] = S_Box[i][(S[i][0] << 1) + S[i][5]][(S[i][1] << 3)
+ (S[i][2] << 2) + (S[i][3] << 1) + S[i][4]];
// 8個數變換輸出二進制
for (j = 0; j < 4; j++) {
sValue[((i * 4) + 3) - j] = sBoxData[i] % 2;
sBoxData[i] = sBoxData[i] / 2;
}
}
for (i = 0; i < 32; i++) {
RP[i] = sValue[P[i] - 1]; // 通過P變換
L1[i] = R0[i]; // 右邊移到左邊
R1[i] = L0[i] + RP[i];
if (R1[i] == 2) {
R1[i] = 0;
}
// 從新合成M，返回數組M
// 最後一次變換時，左右不進行互換。此處採用兩次變換實現不變
if (((flag == 0) && (times == 0)) || ((flag == 1) && (times == 15))) {
M[i] = R1[i];
M[i + 32] = L1[i];
}
else {
M[i] = L1[i];
M[i + 32] = R1[i];
}
}
}
private void GetEncryptResultOfByteArray(int[] data, byte[] value) {
int i;
int j; // 將存儲64位二進制數據的數組中的數據轉換爲八個整數（byte）
for (i = 0; i < 8; i++) {
for (j = 0; j < 8; j++) {
value[i] += (data[(i << 3) + j] << (7 - j));
}
}
for (i = 0; i < 8; i++) {
value[i] %= 256;
if (value[i] > 128) {
value[i] -= 255;
}
}
}
private byte[] ByteDataFormat(byte[] data, int flag) {
int len = data.length;
int padlen = 8 - (len % 8);
int newlen = len + padlen;
byte[] newdata = new byte[newlen];
System.arraycopy(data, 0, newdata, 0, len);
for (int i = len; i < newlen; i++)
newdata[i] = (byte) padlen;
return newdata;
}
public byte[] DesEncrypt(byte[] des_data, int flag) {
byte[] format_key = ByteDataFormat(bytekey, flag);
byte[] format_data = ByteDataFormat(des_data, flag);
int datalen = format_data.length;
int unitcount = datalen / 8;
byte[] result_data = new byte[datalen];
for (int i = 0; i < unitcount; i++) {
byte[] tmpkey = new byte[8];
byte[] tmpdata = new byte[8];
System.arraycopy(format_key, 0, tmpkey, 0, 8);
System.arraycopy(format_data, i * 8, tmpdata, 0, 8);
byte[] tmpresult = UnitDes(tmpkey, tmpdata, flag);
System.arraycopy(tmpresult, 0, result_data, i * 8, 8);
} // 當前爲解密過程，去掉加密時產生的填充位
byte[] decryptbytearray = null;
if (flag == 0) {
int total_len = datalen;
int delete_len = result_data[total_len - 8 - 1];
delete_len = ((delete_len >= 1) && (delete_len <= 8)) ? delete_len : 0;
decryptbytearray = new byte[total_len - delete_len - 8];
boolean del_flag = true;
for (int k = 0; k < delete_len; k++) {
if (delete_len != result_data[total_len - 8 - (k + 1)])
del_flag = false;
}
if (del_flag == true) {
System.arraycopy(result_data, 0, decryptbytearray, 0, total_len- delete_len - 8);
}
}
return (flag == 1) ? result_data : decryptbytearray;
}
public static void main(String[] args) {
String key = "這是密鑰";
String data = "wpy是沙雕";
DES desUtil = new DES(key);
System.err.println("加密前明文：" + data);
// 加密後的byte型的密文
byte[] result = desUtil.DesEncrypt(data.getBytes(), 1);
System.err.println("加密後密文：" + new String(result));
// 下句直接把byte類型的密文解密
System.err.println("解密後明文："+ new String(desUtil.DesEncrypt(result, 0)));
}
}
代碼更改
更改要求
- 1.在項目初步設計時，咱們須要將加解密的明密文進行，文件操做，即將明密文文件讀入在加解密後保存至指定文件夾
- 2.同時須要進行功能選擇，進行加密或解密其中一項
更改主函數代碼實現
public static void main(String[] args) {
Scanner inn = new Scanner(System.in);
System.out.println("請選擇你想要執行的任務：\n1.加密明文;\n2.解密密文");
int choose = inn.nextInt();
if(choose == 1){
System.out.println("請輸入保存明文的文件名：");
String MFile = inn.next();
System.out.println("請輸入加解密所需密鑰：");
String key = inn.next();
String data = "";
int n=-1;
byte [] a=new byte[100];
try{ File f=new File(MFile);
InputStream in = new FileInputStream(f);
while((n=in.read(a,0,100))!=-1) {
data=new String (a,0,n);
}
in.close();
}
catch(IOException e) {
System.out.println("File read Error"+e);
}
DES desUtil = new DES(key);
System.err.println("加密前明文：" + data);
// 加密後的byte型的密文
byte[] result = desUtil.DesEncrypt(data.getBytes(), 1);
System.err.println("加密後密文：" + new String(result));
System.out.println("請輸入保存密文的文件名：");
String MMFile = inn.next();
// 下句直接把byte類型的密文解密
File file = new File(MMFile);
try{
OutputStream out=new FileOutputStream(file);
out.write(result);
out.close();
out=new FileOutputStream(file,true);
}
catch(IOException e) {
System.out.println("Error "+e);
}
}
else if(choose == 2){
System.out.println("請輸入保存密文的文件名：");
String MFile = inn.next();
System.out.println("請輸入加解密所需密鑰：");
String key = inn.next();
String result = "";
int n=-1;
byte [] a=new byte[100];
try{ File f=new File(MFile);
InputStream in = new FileInputStream(f);
while((n=in.read(a,0,100))!=-1) {
result=new String (a,0,n);
}
in.close();
}
catch(IOException e) {
System.out.println("File read Error"+e);
}
DES desUtil = new DES(key);
System.err.println("解密前密文：" + result);
byte [] data = desUtil.DesEncrypt(result.getBytes(), 0);
System.err.println("解密後明文："+ desUtil.DesEncrypt(result.getBytes(), 0));
System.out.println("請輸入保存明文的文件名：");
String MMFile = inn.next();
File file = new File(MMFile);
try{
OutputStream out=new FileOutputStream(file);
out.write(data);
out.close();
out=new FileOutputStream(file,true);
}
catch(IOException e) {
System.out.println("Error "+e);
}
}
}
預覽截圖
施行加密
數組施行解密
函數
遇到還未解決的問題
- DES在更改後解密時因爲密文字符讀入的問題發生誤差，致使解密後的明文Byte數組出現誤差，目前正在找方法解決。
參考資料
相關文章
- 1. DES算法實現
- 2. DES加密算法實現
- 3. DES算法實現（C++版）
- 4. c++實現des算法
- 5. DES算法-C/C++實現
- 6. DES算法的C++實現
- 7. Des算法C++實現
- 8. DES算法（C++實現）
- 9. DES算法實驗
- 10. DES算法原理C++模擬實現
- 更多相關文章...
- • 現實生活中的 XML - XML 教程
- • Hibernate實現增刪改查 - Hibernate教程
- • ☆基於Java Instrument的Agent實現
- • 算法總結-廣度優先算法
相關標籤/搜索
每日一句
-
每一个你不满意的现在，都有一个你没有努力的曾经。
歡迎關注本站公眾號,獲取更多信息
相關文章
- 1. DES算法實現
- 2. DES加密算法實現
- 3. DES算法實現（C++版）
- 4. c++實現des算法
- 5. DES算法-C/C++實現
- 6. DES算法的C++實現
- 7. Des算法C++實現
- 8. DES算法（C++實現）
- 9. DES算法實驗
- 10. DES算法原理C++模擬實現