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#include <stddef.h>
#include "core.h"
#include "crypto_generichash.h"
#include "crypto_kx.h"
#include "crypto_scalarmult.h"
#include "private/common.h"
#include "randombytes.h"
#include "utils.h"
int
crypto_kx_seed_keypair(unsigned char pk[crypto_kx_PUBLICKEYBYTES],
unsigned char sk[crypto_kx_SECRETKEYBYTES],
const unsigned char seed[crypto_kx_SEEDBYTES])
{
crypto_generichash(sk, crypto_kx_SECRETKEYBYTES,
seed, crypto_kx_SEEDBYTES, NULL, 0);
return crypto_scalarmult_base(pk, sk);
}
int
crypto_kx_keypair(unsigned char pk[crypto_kx_PUBLICKEYBYTES],
unsigned char sk[crypto_kx_SECRETKEYBYTES])
{
COMPILER_ASSERT(crypto_kx_SECRETKEYBYTES == crypto_scalarmult_SCALARBYTES);
COMPILER_ASSERT(crypto_kx_PUBLICKEYBYTES == crypto_scalarmult_BYTES);
randombytes_buf(sk, crypto_kx_SECRETKEYBYTES);
return crypto_scalarmult_base(pk, sk);
}
int
crypto_kx_client_session_keys(unsigned char rx[crypto_kx_SESSIONKEYBYTES],
unsigned char tx[crypto_kx_SESSIONKEYBYTES],
const unsigned char client_pk[crypto_kx_PUBLICKEYBYTES],
const unsigned char client_sk[crypto_kx_SECRETKEYBYTES],
const unsigned char server_pk[crypto_kx_PUBLICKEYBYTES])
{
crypto_generichash_state h;
unsigned char q[crypto_scalarmult_BYTES];
unsigned char keys[2 * crypto_kx_SESSIONKEYBYTES];
int i;
if (rx == NULL) {
rx = tx;
}
if (tx == NULL) {
tx = rx;
}
if (rx == NULL) {
sodium_misuse(); /* LCOV_EXCL_LINE */
}
if (crypto_scalarmult(q, client_sk, server_pk) != 0) {
return -1;
}
COMPILER_ASSERT(sizeof keys <= crypto_generichash_BYTES_MAX);
crypto_generichash_init(&h, NULL, 0U, sizeof keys);
crypto_generichash_update(&h, q, crypto_scalarmult_BYTES);
sodium_memzero(q, sizeof q);
crypto_generichash_update(&h, client_pk, crypto_kx_PUBLICKEYBYTES);
crypto_generichash_update(&h, server_pk, crypto_kx_PUBLICKEYBYTES);
crypto_generichash_final(&h, keys, sizeof keys);
sodium_memzero(&h, sizeof h);
for (i = 0; i < crypto_kx_SESSIONKEYBYTES; i++) {
rx[i] = keys[i]; /* rx cannot be NULL */
tx[i] = keys[i + crypto_kx_SESSIONKEYBYTES]; /* tx cannot be NULL */
}
sodium_memzero(keys, sizeof keys);
return 0;
}
int
crypto_kx_server_session_keys(unsigned char rx[crypto_kx_SESSIONKEYBYTES],
unsigned char tx[crypto_kx_SESSIONKEYBYTES],
const unsigned char server_pk[crypto_kx_PUBLICKEYBYTES],
const unsigned char server_sk[crypto_kx_SECRETKEYBYTES],
const unsigned char client_pk[crypto_kx_PUBLICKEYBYTES])
{
crypto_generichash_state h;
unsigned char q[crypto_scalarmult_BYTES];
unsigned char keys[2 * crypto_kx_SESSIONKEYBYTES];
int i;
if (rx == NULL) {
rx = tx;
}
if (tx == NULL) {
tx = rx;
}
if (rx == NULL) {
sodium_misuse(); /* LCOV_EXCL_LINE */
}
if (crypto_scalarmult(q, server_sk, client_pk) != 0) {
return -1;
}
COMPILER_ASSERT(sizeof keys <= crypto_generichash_BYTES_MAX);
crypto_generichash_init(&h, NULL, 0U, sizeof keys);
crypto_generichash_update(&h, q, crypto_scalarmult_BYTES);
sodium_memzero(q, sizeof q);
crypto_generichash_update(&h, client_pk, crypto_kx_PUBLICKEYBYTES);
crypto_generichash_update(&h, server_pk, crypto_kx_PUBLICKEYBYTES);
crypto_generichash_final(&h, keys, sizeof keys);
sodium_memzero(&h, sizeof h);
for (i = 0; i < crypto_kx_SESSIONKEYBYTES; i++) {
tx[i] = keys[i];
rx[i] = keys[i + crypto_kx_SESSIONKEYBYTES];
}
sodium_memzero(keys, sizeof keys);
return 0;
}
size_t
crypto_kx_publickeybytes(void)
{
return crypto_kx_PUBLICKEYBYTES;
}
size_t
crypto_kx_secretkeybytes(void)
{
return crypto_kx_SECRETKEYBYTES;
}
size_t
crypto_kx_seedbytes(void)
{
return crypto_kx_SEEDBYTES;
}
size_t
crypto_kx_sessionkeybytes(void)
{
return crypto_kx_SESSIONKEYBYTES;
}
const char *
crypto_kx_primitive(void)
{
return crypto_kx_PRIMITIVE;
}
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