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rsa branch backup

This commit is contained in:
gbrochar 2024-02-15 21:25:35 +01:00
parent 038719bb26
commit 6a077bca3f
7 changed files with 320 additions and 41 deletions
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36
rsa/ft_strjoin.c Normal file
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@ -0,0 +1,36 @@
/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* ft_strjoin.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: gbrochar <marvin@42.fr> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2015/11/29 09:48:11 by gbrochar #+# #+# */
/* Updated: 2024/02/15 15:38:50 by gbrochar ### ########.fr */
/* */
/* ************************************************************************** */
#include "rsa.h"
char *ft_strjoin(char const *s1, char const *s2)
{
char *str;
size_t len;
size_t i;
i = 0;
len = ft_strlen(s1) + ft_strlen(s2);
str = (char *)malloc((len + 1) * sizeof(char));
if (!str)
return (NULL);
while (i < len)
{
if (i < ft_strlen(s1))
str[i] = s1[i];
else
str[i] = s2[i - ft_strlen(s1)];
i++;
}
str[i] = '\0';
return (str);
}

23
rsa/ft_strlen.c Normal file
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@ -0,0 +1,23 @@
/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* ft_strlen.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: gbrochar <marvin@42.fr> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2015/11/25 14:43:32 by gbrochar #+# #+# */
/* Updated: 2024/02/15 15:39:11 by gbrochar ### ########.fr */
/* */
/* ************************************************************************** */
#include "rsa.h"
size_t ft_strlen(const char *s)
{
int i;
i = 0;
while (s[i])
i++;
return (i);
}

242
rsa/generate_keys.c
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@ -1,53 +1,187 @@
#include "rsa.h"
int *random_bits(int n) {
void set_random_bits(int *n, int size) {
int fd = open("/dev/urandom", O_RDONLY);
ft_log(INFO, "fd");
ft_log(INFO, ft_itoa(fd));
int *random_bits = (int *)malloc(n >> 3);
if (!random_bits) {
ft_log(ERROR, "allocation failed on random_bits");
exit(1);
}
ft_log(INFO, "before read");
read(fd, random_bits, n >> 3, 0);
ft_log(INFO, "after read");
// set n bits to random values
// for (int i = 0; i < n >> 5; i++) {
// random_bits[i] = rand();
// }
// set LSB and MSB to 1
random_bits[0] |= 1;
printf("last %ud\n", random_bits[(n / sizeof(int) >> 3) - 1]);
random_bits[(n / sizeof(int) >> 3) - 1] |= 0x80000000;
printf("last %ud\n", random_bits[(n / sizeof(int) >> 3) - 1]);
return random_bits;
read(fd, n, size);
}
void bitshift_array(int *a, int len) {
void set_msb_and_lsb_to_one(int *n, int size) {
n[0] |= 1;
n[size / sizeof(int) - 1] |= 1 << 31;
}
/*
int *random_bits(int n) {
int fd = open("/dev/urandom", O_RDONLY);
ft_log(INFO, "fd");
ft_log(INFO, ft_itoa(fd));
int *random_bits = (int *)malloc(n >> 3);
if (!random_bits) {
ft_log(ERROR, "allocation failed on random_bits");
exit(1);
}
ft_log(INFO, "before read");
read(fd, random_bits, n >> 3, 0);
ft_log(INFO, "after read");
// set n bits to random values
// for (int i = 0; i < n >> 5; i++) {
// random_bits[i] = rand();
// }
// set LSB and MSB to 1
random_bits[0] |= 1;
printf("last %ud\n", random_bits[(n / sizeof(int) >> 3) - 1]);
random_bits[(n / sizeof(int) >> 3) - 1] |= 0x80000000;
printf("last %ud\n", random_bits[(n / sizeof(int) >> 3) - 1]);
return random_bits;
}
*/
/*
void bitshift_array(int *a, int len) {
for (int n = 0; n < len - 1; n++) {
a[n] = a[n] >> 1 | (a[n + 1] & 1) << 31;
}
a[len - 1] >>= 1;
}
*/
void array_bitwise_right_shift(int *a, int len) {
int size = sizeof(int) * 8 - 1;
for (int n = 0; n < len - 1; n++) {
a[n] = a[n] >> 1 | (a[n + 1] & 1) << 31;
a[n] = a[n] >> 1 | (a[n + 1] & 1) << size;
}
a[len - 1] >>= 1;
}
int *generate_a(int *n) {
int *a = (int *)malloc(RSA_SIZE_BYTES >> 1);
memcpy(a, n, RSA_SIZE_BYTES >> 1);
a[0] -= 1;
void array_bitwise_left_shift(int *a, int len) {
int size = sizeof(int) * 8 - 1;
for (int n = len - 1; n > 0; n--) {
a[n] = a[n] << 1 | ((a[n - 1] & (1 << size)) >> size);
}
a[0] <<= 1;
}
// Will underflow
void array_decrement(int *a, int len) {
int cursor = 0;
// a = n - 2
while (1) {
a[cursor / 32] = a[cursor / 32] ^ (1 << (cursor % 32));
if ((a[cursor / 32] >> (cursor % 32)) & 1 == 0)
break;
cursor++;
int size = sizeof(int) * 8;
while (cursor < size * len) {
a[cursor / size] = a[cursor / size] ^ (1 << (cursor % size));
if ((a[cursor / size] >> (cursor % size)) & 1 == 0) {
return;
}
cursor += 1;
}
}
int *large_mod(int *a, int *b) {
int len = RSA_SIZE_BYTES / sizeof(int) >> 1;
//for (int i = len - 1; i > -1; i--)
/*
int *generate_a(int *n) {
int *a = (int *)malloc(RSA_SIZE_BYTES >> 1);
memcpy(a, n, RSA_SIZE_BYTES >> 1);
a[0] -= 1;
int cursor = 0;
// a = n - 2
while (1) {
a[cursor / 32] = a[cursor / 32] ^ (1 << (cursor % 32));
if ((a[cursor / 32] >> (cursor % 32)) & 1 == 0)
break;
cursor++;
}
}
*/
int large_cmp(t_bigint *a, t_bitint *b) {
int size = sizeof(int) * 8;
int alen = a.size / sizeof(int);
int blen = b.size / sizeof(int);
int acursor = size * alen - 1;
int bcursor = size * alen - 1;
while (acursor > bcursor) {
if (a[acursor / size] & (1 << acursor % size)) {
return 1;
}
acursor -= 1;
}
while (bcursor > acursor) {
if (b[bcursor / size] & (1 << bcursor % size)) {
return -1;
}
bcursor -= 1;
}
int cursor = acursor;
while (cursor >= 0) {
int abit = a[cursor / size] & (1 << cursor % size);
int bbit = b[cursor / size] & (1 << cursor % size);
if (abit > bbit) {
return 1;
}
if (bbit > abit) {
return -1;
}
}
return 0;
}
t_bigint bigint_clone(t_bigint src) {
t_bitint dst;
bigint.size = src.size;
bigint.data = (int *)protected_malloc(bigint.size, "bigint.data in bigint_clone");
memcpy(bigint.data, src.data, size);
}
int *bigint_sub(t_bigint *a, t_bigint *b) {
int *tmp = (int *)protected_malloc(size)
}
int *bigint_mod(t_bigint *a, t_bigint *b) {
int size = sizeof(int) * 8;
int alen = a.size / sizeof(int);
int blen = b.size / sizeof(int);
int acursor = size * alen - 1;
int bcursor = size * blen - 1;
t_bigint bclone = bigint_clone(b);
int cmp = large_cmp(a, b);
if (cmp == 0) {
}
while (!(a[acursor / size] & (1 << acursor % size))) {
acursor -= 1;
}
while (!(b[bcursor / size] & (1 << bcursor % size))) {
bcursor -= 1;
}
int bpow = 0;
if (acursor < bcursor) {
return a.data;
}
while (large_cmp(a, bclone) == 1) {
while (large_cmp(a, b) == 1) {
array_bitwise_left_shift(b, blen);
bcursor += 1;
bpow += 1;
}
array_bitwise_right_shift(b, blen);
bcursor -= 1;
bpow -= 1;
a.data = bigint_sub(a, b);
}
}
void generate_prime(int *n, int size) {
set_random_bits(n, size);
set_msb_and_lsb_to_one(n, size);
// n - 1 = 2^s*d
int *d = (int *)protected_malloc(size, "d in generate_prime");
d[0] -= 1;
int s = 0;
while (!(d[0] & 1)) {
s += 1;
array_bitwise_right_shift(d, size / sizeof(int));
}
}
void generate_prime(int *n) {
@ -74,7 +208,7 @@ void generate_prime(int *n) {
bitshift_array(d, RSA_SIZE_BYTES / sizeof(int) >> 1);
}
for (int k = 0; k < 128; k++) {
// int *a = generate_a(prime);
// int *a = generate_a(prime);
}
}
@ -82,6 +216,40 @@ int *ft_phi(int *p, int *q) {
return (int *)malloc(sizeof(int));
}
t_rsa rsa_allocate(int block_size) {
t_rsa rsa;
rsa.p.size = block_size;
rsa.q.size = block_size;
rsa.n.size = 2 * block_size;
rsa.e.size = block_size;
rsa.p.data = (int *)protected_malloc(rsa.p.size, "rsa.p.size");
rsa.q.data = (int *)protected_malloc(rsa.q.size, "rsa.q.size");
rsa.n.data = (int *)protected_malloc(rsa.n.size, "rsa.n.size");
rsa.e.data = (int *)protected_malloc(rsa.e.size, "rsa.e.size");
for (int i = 0; i < block_size / sizeof(int)) {
rsa.p.data[i] = 0;
rsa.q.data[i] = 0;
rsa.e.data[i] = 0;
}
for (int i = 0; i < 2 * block_size / sizeof(int)) {
rsa.n.data[i] = 0;
}
}
t_rsa rsa_new(int block_size) {
t_rsa rsa;
// Convert block_size to bytes
block_size /= 8;
rsa = rsa_allocate(block_size);
generate_prime(rsa.p.data, block_size / 2);
generate_prime(rsa.q.data, block_size / 2);
return rsa;
}
void generate_keys(int *p, int *q, int *e) {
ft_log(INFO, "Generating primes...");
p = 0;

30
rsa/guide.txt Normal file
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@ -0,0 +1,30 @@
Soit p et q deux nombres premiers
n = p * q
phi(n) = (p - 1)(q - 1)
choisir e tel que gcd(phi(n), e) = 1
soit un message m
on veut creer un message chiffre c a partir de m
c = m^e mod(n)
ed = 1 mod(phi)
m = c^d mod(n)
Les nombres doivent etre d'une taille arbitraire.
Ils seront stocker dans un tableau.
Il faut definir une structure pour decrire un grand nombre.
Ainsi que plusieurs operations : addition, multiplication, soustraction et modulo.
Il faut soit changer la taille des nombre quand necessaire, soit definir une taille fixe pour chacun des nombres, ce qui est plus simple.
len == length of array
s_bigint {
uint32_t *data;
size_t len;
}

8
rsa/lib.c
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@ -1,5 +1,13 @@
#include "rsa.h"
void *protected_malloc(size_t size, char *str) {
void *ptr = malloc(size);
if (!ptr) {
ft_log(ERROR, ft_strjoin(ft_strjoin("allocation of ", str), " failed"));
exit(1);
}
}
void ft_log(int level, char *s) {
switch (level) {
case ERROR:

5
rsa/main.c
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@ -13,11 +13,8 @@ int main(int ac, char **av) {
ft_log(INFO, ft_itoa(RAND_MAX));
int m = atoi(av[1]);
srand(time(NULL));
int *p;
int *q;
int *e;
ft_log(INFO, "Generating keys...");
generate_keys(p, q, e);
t_rsa rsa = rsa_new(RSA_SIZE);
} else {
ft_log(WARNING, "Need to pass message as argument");
return 1;

17
rsa/rsa.h
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@ -17,13 +17,30 @@
#define WARNING 1
#define INFO 2
typedef struct s_rsa {
t_bigint p;
t_bigint q;
t_bigint n;
t_bigint e;
} t_rsa;
typedef struct s_bigint {
int *data;
int size;
} t_bigint;
void ft_log(int level, char *s);
char *ft_itoa(int n);
size_t ft_strlen(const char *s);
char *ft_strjoin(char const *s1, char const *s2);
void generate_keys(int *p, int *q, int *e);
int *random_bits(int n);
void generate_prime(int *p);
int *phi(int *p, int *q);
t_rsa rsa_new(int block_size);
#endif