summaryrefslogtreecommitdiff
path: root/set5/task39.c
blob: 42c675cbb0df030cac7de1c404f89fdc3fa4c950 (plain)
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
#include "../lib/lib.h"
#include "../lib/lib2.h"
#include "../lib/lib3.h"
#include "../lib/lib4.h"
#include "../lib/lib5.h"
#include <time.h>

#include<openssl/bn.h>
#include<openssl/bio.h>


int main_littlenum()
{
	int message = 65;
	int p = 5, q = 11;
	int n = p * q;
	int et = (p-1) * (q-1);
	int e = 3;

	// does not work, nums are above INT_MAX
	int d = modular_multiplicative_inverse(e, et);
	// public key is [e, n], private key is [d, n]
	struct rsa_key public = { .exponent = e, .modulo = n };
	struct rsa_key private = { .exponent = d, .modulo = n };
	printf("public key is: %i, %i\n", public.exponent, public.modulo);
	printf("private key is: %i, %i\n", private.exponent, private.modulo);
	int ciphertext = rsa_encrypt(message, &public);
	printf("encrpyt %i: %i\n", message, ciphertext);
	int dec_message = rsa_decrpyt(ciphertext, &private);
	printf("decrypt %i: %i\n", ciphertext, dec_message);
	return 0;
}

#define BN_DEBUG

int main()
{
	
	struct rsa_key_bignum private, public;
	// debugging: printing BN's
	BIO *out = BIO_new(BIO_s_file());
	BIO_set_fp(out, stdout, BIO_NOCLOSE);

	ctx = BN_CTX_new();
	
	rsa_generate_key_bignum(&private, &public);

	printf("message:\n");
	unsigned char *mess = "Hello, i wanna get encrypted";
	printf("%s\n", mess);
	BIGNUM *message = BN_bin2bn(mess, strlen(mess), NULL);
	//BIGNUM *message = BN_new();
	//BN_set_word(message, 4234667);
	BIGNUM *encrypted = BN_new();
	BIGNUM *decrypted = BN_new();
	BN_print(out, message);

	if(!rsa_encrypt_bignum(message, encrypted, &public))
		die("could not rsa encrypt message");

	printf("\nencrypted rsa message\n");
	BN_print(out, encrypted);

	if(!rsa_decrypt_bignum(encrypted, decrypted, &private))
		die("could not rsa decrypt");

	printf("\ndecrypted message:\n");
	BN_print(out, decrypted);
	
	unsigned char *dec_mess = malloc(BN_num_bytes(decrypted));
	BN_bn2bin(decrypted, dec_mess);
	printf("\ndecrepyted message:\n%s\n", dec_mess);
	BN_CTX_free(ctx);
	free_rsa_key_bignum(&private);
	free(public.exponent);
}