diff options
Diffstat (limited to 'curve.h')
| -rw-r--r-- | curve.h | 218 |
1 files changed, 218 insertions, 0 deletions
@@ -0,0 +1,218 @@ +/* + * 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 "xio.h" +#include "crypto_box_curve25519xsalsa20poly1305.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, +}; + +#define crypto_box_zerobytes crypto_box_curve25519xsalsa20poly1305_ZEROBYTES +#define crypto_box_boxzerobytes crypto_box_curve25519xsalsa20poly1305_BOXZEROBYTES + +#define crypto_box_noncebytes crypto_box_curve25519xsalsa20poly1305_NONCEBYTES +#define crypto_box_beforenmbytes crypto_box_curve25519xsalsa20poly1305_BEFORENMBYTES + +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 */ |