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/*
* netsniff-ng - the packet sniffing beast
* Copyright 2011 - 2013 Daniel Borkmann.
* Subject to the GPL, version 2.
*/
#ifndef CURVE_H
#define CURVE_H
#include <stdint.h>
#include <sys/time.h>
#include "locking.h"
#include "built_in.h"
#include "ioops.h"
#include "rnd.h"
#include "crypto.h"
struct tai {
uint64_t x;
};
struct taia {
struct tai sec;
uint32_t nano;
uint32_t atto;
};
static struct taia tolerance_taia = {
.sec.x = 0,
.nano = 700000000ULL,
.atto = 0,
};
struct curve25519_proto {
unsigned char enonce[crypto_box_noncebytes] __aligned_16;
unsigned char dnonce[crypto_box_noncebytes] __aligned_16;
unsigned char key[crypto_box_noncebytes] __aligned_16;
};
struct curve25519_struct {
unsigned char *enc_buf;
unsigned char *dec_buf;
size_t enc_buf_size;
size_t dec_buf_size;
struct spinlock enc_lock;
struct spinlock dec_lock;
};
extern void curve25519_selftest(void);
extern void curve25519_alloc_or_maybe_die(struct curve25519_struct *curve);
extern void curve25519_free(void *curve);
extern int curve25519_pubkey_hexparse_32(unsigned char *bin, size_t blen, const char *ascii, size_t alen);
extern int curve25519_proto_init(struct curve25519_proto *proto, unsigned char *pubkey_remote, size_t len,
char *home, int server);
extern ssize_t curve25519_encode(struct curve25519_struct *curve, struct curve25519_proto *proto,
unsigned char *plaintext, size_t size, unsigned char **chipertext);
extern ssize_t curve25519_decode(struct curve25519_struct *curve, struct curve25519_proto *proto,
unsigned char *chipertext, size_t size, unsigned char **plaintext,
struct taia *arrival_taia);
static inline void tai_pack(unsigned char *s, struct tai *t)
{
uint64_t x;
x = t->x;
s[7] = x & 255; x >>= 8;
s[6] = x & 255; x >>= 8;
s[5] = x & 255; x >>= 8;
s[4] = x & 255; x >>= 8;
s[3] = x & 255; x >>= 8;
s[2] = x & 255; x >>= 8;
s[1] = x & 255; x >>= 8;
s[0] = x;
}
static inline void tai_unpack(unsigned char *s, struct tai *t)
{
uint64_t x;
x = (unsigned char) s[0];
x <<= 8; x += (unsigned char) s[1];
x <<= 8; x += (unsigned char) s[2];
x <<= 8; x += (unsigned char) s[3];
x <<= 8; x += (unsigned char) s[4];
x <<= 8; x += (unsigned char) s[5];
x <<= 8; x += (unsigned char) s[6];
x <<= 8; x += (unsigned char) s[7];
t->x = x;
}
static inline void taia_pack(unsigned char *s, struct taia *t)
{
unsigned long x;
tai_pack(s, &t->sec);
s += 8;
x = t->atto;
s[7] = x & 255; x >>= 8;
s[6] = x & 255; x >>= 8;
s[5] = x & 255; x >>= 8;
s[4] = x;
x = t->nano;
s[3] = x & 255; x >>= 8;
s[2] = x & 255; x >>= 8;
s[1] = x & 255; x >>= 8;
s[0] = x;
}
static inline void taia_unpack(unsigned char *s, struct taia *t)
{
unsigned long x;
tai_unpack(s, &t->sec);
s += 8;
x = (unsigned char) s[4];
x <<= 8; x += (unsigned char) s[5];
x <<= 8; x += (unsigned char) s[6];
x <<= 8; x += (unsigned char) s[7];
t->atto = x;
x = (unsigned char) s[0];
x <<= 8; x += (unsigned char) s[1];
x <<= 8; x += (unsigned char) s[2];
x <<= 8; x += (unsigned char) s[3];
t->nano = x;
}
#define tai_unix(t, u) ((void) ((t)->x = 4611686018427387914ULL + (uint64_t) (u)))
static inline void taia_now(struct taia *t)
{
struct timeval now;
gettimeofday(&now, NULL);
tai_unix(&t->sec, now.tv_sec);
t->nano = 1000 * now.tv_usec + 500;
t->atto = secrand();
}
static inline void taia_sub(struct taia *res, const struct taia *u, const struct taia *v)
{
unsigned long unano = u->nano;
unsigned long uatto = u->atto;
res->sec.x = u->sec.x - v->sec.x;
res->nano = unano - v->nano;
res->atto = uatto - v->atto;
if (res->atto > uatto) {
res->atto += 1000000000UL;
--res->nano;
}
if (res->nano > unano) {
res->nano += 1000000000UL;
--res->sec.x;
}
}
static inline void taia_add(struct taia *res, const struct taia *u, const struct taia *v)
{
res->sec.x = u->sec.x + v->sec.x;
res->nano = u->nano + v->nano;
res->atto = u->atto + v->atto;
if (res->atto > 999999999UL) {
res->atto -= 1000000000UL;
++res->nano;
}
if (res->nano > 999999999UL) {
res->nano -= 1000000000UL;
++res->sec.x;
}
}
static inline int taia_less(const struct taia *t, const struct taia *u)
{
if (t->sec.x < u->sec.x)
return 1;
if (t->sec.x > u->sec.x)
return 0;
if (t->nano < u->nano)
return 1;
if (t->nano > u->nano)
return 0;
return t->atto < u->atto;
}
static inline int is_good_taia(struct taia *arrival_taia, struct taia *packet_taia)
{
int is_ts_good = 0;
struct taia sub_res;
if (taia_less(arrival_taia, packet_taia)) {
taia_sub(&sub_res, packet_taia, arrival_taia);
if (taia_less(&sub_res, &tolerance_taia))
is_ts_good = 1;
else
is_ts_good = 0;
} else {
taia_sub(&sub_res, arrival_taia, packet_taia);
if (taia_less(&sub_res, &tolerance_taia))
is_ts_good = 1;
else
is_ts_good = 0;
}
return is_ts_good;
}
#endif /* CURVE_H */
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