hs_ident.c

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/* Copyright (c) 2017-2021, The Tor Project, Inc. */
/* See LICENSE for licensing information */
 
/**
 * \file hs_ident.c
 * \brief Contains circuit and connection identifier code for the whole HS
 *        subsystem.
 **/
 
#include "lib/crypt_ops/crypto_util.h"
#include "feature/hs/hs_ident.h"
 
/** Return a newly allocated circuit identifier. The given public key is copied
 * identity_pk into the identifier. */
hs_ident_circuit_t *
hs_ident_circuit_new(const ed25519_public_key_t *identity_pk)
{
  hs_ident_circuit_t *ident = tor_malloc_zero(sizeof(*ident));
  ed25519_pubkey_copy(&ident->identity_pk, identity_pk);
  return ident;
}
 
/** Free the given circuit identifier. */
void
hs_ident_circuit_free_(hs_ident_circuit_t *ident)
{
  if (ident == NULL) {
    return;
  }
  memwipe(ident, 0, sizeof(hs_ident_circuit_t));
  tor_free(ident);
}
 
/** For a given circuit identifier src, return a newly allocated copy of it.
 * This can't fail. */
hs_ident_circuit_t *
hs_ident_circuit_dup(const hs_ident_circuit_t *src)
{
  hs_ident_circuit_t *ident = tor_malloc_zero(sizeof(*ident));
  memcpy(ident, src, sizeof(*ident));
  return ident;
}
 
/** For a given directory connection identifier src, return a newly allocated
 * copy of it. This can't fail. */
hs_ident_dir_conn_t *
hs_ident_dir_conn_dup(const hs_ident_dir_conn_t *src)
{
  hs_ident_dir_conn_t *ident = tor_malloc_zero(sizeof(*ident));
  memcpy(ident, src, sizeof(*ident));
  return ident;
}
 
/** Free the given directory connection identifier. */
void
hs_ident_dir_conn_free_(hs_ident_dir_conn_t *ident)
{
  if (ident == NULL) {
    return;
  }
  memwipe(ident, 0, sizeof(hs_ident_dir_conn_t));
  tor_free(ident);
}
 
/** Return a newly allocated HS directory connection identifier that is meant
 * for the server side (HSDir). Only the blinded key is known by the HSDir. */
hs_ident_dir_conn_t *
hs_ident_server_dir_conn_new(const ed25519_public_key_t *blinded_pk)
{
  hs_ident_dir_conn_t *ident = tor_malloc_zero(sizeof(*ident));
  ed25519_pubkey_copy(&ident->blinded_pk, blinded_pk);
  return ident;
}
 
/** Initialized the allocated ident object with identity_pk and blinded_pk.
 * None of them can be NULL since a valid directory connection identifier must
 * have all fields set. */
void
hs_ident_dir_conn_init(const ed25519_public_key_t *identity_pk,
                       const ed25519_public_key_t *blinded_pk,
                       hs_ident_dir_conn_t *ident)
{
  tor_assert(identity_pk);
  tor_assert(blinded_pk);
  tor_assert(ident);
 
  ed25519_pubkey_copy(&ident->identity_pk, identity_pk);
  ed25519_pubkey_copy(&ident->blinded_pk, blinded_pk);
}
 
/** Return a newly allocated edge connection identifier. The given public key
 * identity_pk is copied into the identifier. */
hs_ident_edge_conn_t *
hs_ident_edge_conn_new(const ed25519_public_key_t *identity_pk)
{
  hs_ident_edge_conn_t *ident = tor_malloc_zero(sizeof(*ident));
  ed25519_pubkey_copy(&ident->identity_pk, identity_pk);
  return ident;
}
 
/** Free the given edge connection identifier. */
void
hs_ident_edge_conn_free_(hs_ident_edge_conn_t *ident)
{
  if (ident == NULL) {
    return;
  }
  memwipe(ident, 0, sizeof(hs_ident_edge_conn_t));
  tor_free(ident);
}
 
/** Return true if the given ident is valid for an introduction circuit. */
int
hs_ident_intro_circ_is_valid(const hs_ident_circuit_t *ident)
{
  if (ident == NULL) {
    goto invalid;
  }
 
  if (ed25519_public_key_is_zero(&ident->identity_pk)) {
    goto invalid;
  }
 
  if (ed25519_public_key_is_zero(&ident->intro_auth_pk)) {
    goto invalid;
  }
 
  /* Valid. */
  return 1;
 invalid:
  return 0;
}