1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
#include <windows.h>
#include <cmath>
#include <vector>
class CryptoClass
{
long publickey;
long privatekey;
long modl; //Modulus
public :
CryptoClass(); //To be used to just generate private and public keys.
CryptoClass(long &,long &,long &);//To be used just to generate private and public keys.
CryptoClass(long key,long modulus) // Should be used when a data is to be encrypted or decrypted using a key.
{
publickey = privatekey = key;
modl = modulus;
}
long ret_publickey()
{
return publickey;
}
long ret_privatekey()
{
return privatekey;
}
long ret_modulus()
{
return modl;
}
bool isPrime(long);
void encrypt(char *);
void decrypt(char *);
long genrndprimes(int , int);
long genrndnum(int , int);
int gcd ( int, int);
int totient(int);
};
CryptoClass::CryptoClass()
{
long p1,p2; //Prime numbers
long n = 0; //Modulus
long phi =0; //Totient value.
long e = 0; //Public key exponent.
long d = 0; //Private key exponent.
p1 = genrndprimes(100,900);
p2 = genrndprimes(100,900);
n = p1*p2;
phi = totient(n);
e = genrndnum(2,(phi-1));
while(gcd(e,phi)!=1)
{
e = genrndnum(2,(phi-1));
}
d = (1/e)%phi; //Modular Multiplicative Inverse.
privatekey = e;
publickey = d;
modl = n;
}
CryptoClass::CryptoClass(long &pubkey,long &privkey,long &mdls)
{
long p1,p2; //Prime numbers
long n = 0; //Modulus
long phi =0; //Totient value.
long e = 0; //Public key exponent.
long d = 0; //Private key exponent.
p1 = genrndprimes(100,900);
Sleep(1000);
p1 = genrndprimes(100,900);
n = p1*p2;
phi = totient(n);
e = genrndnum(2,(phi-1));
while(gcd(e,phi)!=1)
{
e = genrndnum(2,(phi-1));
}
d = (1/e)%phi; //Modular Multiplicative Inverse.
privatekey = e;
publickey = d;
pubkey = publickey;
privkey = privatekey;
mdls = n;
modl = n;
}
void CryptoClass::encrypt(char *dat)
{
long siz = strlen(dat);
for(long i=0;i<siz;i++)
{
dat[i]=(long)pow((double)dat[i],publickey) % modl;
}
}
void CryptoClass::decrypt(char *datn)
{
long sizz = strlen(datn);
for(long i=0;i<sizz;i++)
{
datn[i]=(long)pow((double)datn[i],privatekey)%modl;
}
}
long CryptoClass::genrndprimes(int a, int b){
long pivot;
do{
pivot= rand() % b + a;
if (isPrime(pivot))
return pivot;
} while (1==1);
}
bool CryptoClass::isPrime(long pivot) {
if(pivot <= 1)
return false;
int root = sqrt((double)pivot);
//start at 2 because all numbers are divisible by 1
for(int x = 2; x <= root; x++) //You only need to check up to and including the root
{
if(pivot % x == 0)
return false;
}
return true;
}
long CryptoClass::genrndnum(int a, int b){
long pivot;
pivot= rand() % b + a;
return pivot;
}
int CryptoClass::gcd ( int a, int b )
{
int c;
while ( a != 0 ) {
c = a; a = b%a; b = c;
}
return b;
}
int CryptoClass::totient(int n)
{
if (n == 1)
return 1ll;
int out = n;
// 2
if (n % 2 == 0) {
out -= out / 2;
do
n /= 2;
while (n % 2 == 0);
}
// odds
for (int i = 3; i * i <= n; i += 2)
if (n % i == 0) {
out -= out / i;
do
n /= i;
while (n % i == 0);
}
//
if (n > 1)
out -= out / n;
return out;
}
|
