transmission/libtransmission/crypto-utils-cyassl.c

/*
 * This file Copyright (C) 2014-2015 Mnemosyne LLC
 *
 * It may be used under the GNU GPL versions 2 or 3
 * or any future license endorsed by Mnemosyne LLC.
 *
 */

#if defined (CYASSL_IS_WOLFSSL)
 #define API_HEADER(x) <wolfssl/x>
 #define API_HEADER_CRYPT(x) API_HEADER (wolfcrypt/x)
 #define API(x) wc_##x
 #define API_VERSION_HEX LIBWOLFSSL_VERSION_HEX
#else
 #define API_HEADER(x) <cyassl/x>
 #define API_HEADER_CRYPT(x) API_HEADER (ctaocrypt/x)
 #define API(x) x
 #define API_VERSION_HEX LIBCYASSL_VERSION_HEX
#endif

#include <assert.h>

#include API_HEADER_CRYPT (arc4.h)
#include API_HEADER_CRYPT (dh.h)
#include API_HEADER_CRYPT (error-crypt.h)
#include API_HEADER_CRYPT (random.h)
#include API_HEADER_CRYPT (sha.h)
#include API_HEADER (version.h)

#include "transmission.h"
#include "crypto-utils.h"
#include "log.h"
#include "platform.h"
#include "utils.h"

#define TR_CRYPTO_DH_SECRET_FALLBACK
#include "crypto-utils-fallback.c"

struct tr_dh_ctx
{
  DhKey     dh;
  word32    key_length;
  uint8_t * private_key;
  word32    private_key_length;
};

/***
****
***/

#define MY_NAME "tr_crypto_utils"

static void
log_cyassl_error (int          error_code,
                  const char * file,
                  int          line)
{
  if (tr_logLevelIsActive (TR_LOG_ERROR))
    {
#if API_VERSION_HEX >= 0x03004000
      const char * error_message = API (GetErrorString) (error_code);
#elif API_VERSION_HEX >= 0x03000002
      const char * error_message = CTaoCryptGetErrorString (error_code);
#else
      char error_message[CYASSL_MAX_ERROR_SZ];
      CTaoCryptErrorString (error_code, error_message);
#endif

      tr_logAddMessage (file, line, TR_LOG_ERROR, MY_NAME, "CyaSSL error: %s", error_message);
    }
}

static bool
check_cyassl_result (int          result,
                     const char * file,
                     int          line)
{
  const bool ret = result == 0;
  if (!ret)
    log_cyassl_error (result, file, line);
  return ret;
}

#define check_result(result) check_cyassl_result ((result), __FILE__, __LINE__)

/***
****
***/

static RNG *
get_rng (void)
{
  static RNG rng;
  static bool rng_initialized = false;

  if (!rng_initialized)
    {
      if (!check_result (API (InitRng) (&rng)))
        return NULL;
      rng_initialized = true;
    }

  return &rng;
}

static tr_lock *
get_rng_lock (void)
{
  static tr_lock * lock = NULL;

  if (lock == NULL)
    lock = tr_lockNew ();

  return lock;
}

/***
****
***/

tr_sha1_ctx_t
tr_sha1_init (void)
{
  Sha * handle = tr_new (Sha, 1);

  if (check_result (API (InitSha) (handle)))
    return handle;

  tr_free (handle);
  return NULL;
}

bool
tr_sha1_update (tr_sha1_ctx_t   handle,
                const void    * data,
                size_t          data_length)
{
  assert (handle != NULL);

  if (data_length == 0)
    return true;

  assert (data != NULL);

  return check_result (API (ShaUpdate) (handle, data, data_length));
}

bool
tr_sha1_final (tr_sha1_ctx_t   handle,
               uint8_t       * hash)
{
  bool ret = true;

  if (hash != NULL)
    {
      assert (handle != NULL);

      ret = check_result (API (ShaFinal) (handle, hash));
    }

  tr_free (handle);
  return ret;
}

/***
****
***/

tr_rc4_ctx_t
tr_rc4_new (void)
{
  return tr_new0 (Arc4, 1);
}

void
tr_rc4_free (tr_rc4_ctx_t handle)
{
  tr_free (handle);
}

void
tr_rc4_set_key (tr_rc4_ctx_t    handle,
                const uint8_t * key,
                size_t          key_length)
{
  assert (handle != NULL);
  assert (key != NULL);

  API (Arc4SetKey) (handle, key, key_length);
}

void
tr_rc4_process (tr_rc4_ctx_t   handle,
                const void   * input,
                void         * output,
                size_t         length)
{
  assert (handle != NULL);

  if (length == 0)
    return;

  assert (input != NULL);
  assert (output != NULL);

  API (Arc4Process) (handle, output, input, length);
}

/***
****
***/

tr_dh_ctx_t
tr_dh_new (const uint8_t * prime_num,
           size_t          prime_num_length,
           const uint8_t * generator_num,
           size_t          generator_num_length)
{
  struct tr_dh_ctx * handle = tr_new0 (struct tr_dh_ctx, 1);

  assert (prime_num != NULL);
  assert (generator_num != NULL);

  API (InitDhKey) (&handle->dh);
  if (!check_result (API (DhSetKey) (&handle->dh,
                                     prime_num, prime_num_length,
                                     generator_num, generator_num_length)))
    {
      tr_free (handle);
      return NULL;
    }

  handle->key_length = prime_num_length;

  return handle;
}

void
tr_dh_free (tr_dh_ctx_t raw_handle)
{
  struct tr_dh_ctx * handle = raw_handle;

  if (handle == NULL)
    return;

  API (FreeDhKey) (&handle->dh);
  tr_free (handle->private_key);
  tr_free (handle);
}

bool
tr_dh_make_key (tr_dh_ctx_t   raw_handle,
                size_t        private_key_length UNUSED,
                uint8_t     * public_key,
                size_t      * public_key_length)
{
  struct tr_dh_ctx * handle = raw_handle;
  word32 my_private_key_length, my_public_key_length;
  tr_lock * rng_lock = get_rng_lock ();

  assert (handle != NULL);
  assert (public_key != NULL);

  if (handle->private_key == NULL)
    handle->private_key = tr_malloc (handle->key_length);

  tr_lockLock (rng_lock);

  if (!check_result (API (DhGenerateKeyPair) (&handle->dh, get_rng (),
                                              handle->private_key, &my_private_key_length,
                                              public_key, &my_public_key_length)))
    {
      tr_lockUnlock (rng_lock);
      return false;
    }

  tr_lockUnlock (rng_lock);

  tr_dh_align_key (public_key, my_public_key_length, handle->key_length);

  handle->private_key_length = my_private_key_length;

  if (public_key_length != NULL)
    *public_key_length = handle->key_length;

  return true;
}

tr_dh_secret_t
tr_dh_agree (tr_dh_ctx_t     raw_handle,
             const uint8_t * other_public_key,
             size_t          other_public_key_length)
{
  struct tr_dh_ctx * handle = raw_handle;
  struct tr_dh_secret * ret;
  word32 my_secret_key_length;

  assert (handle != NULL);
  assert (other_public_key != NULL);

  ret = tr_dh_secret_new (handle->key_length);

  if (check_result (API (DhAgree) (&handle->dh,
                                   ret->key, &my_secret_key_length,
                                   handle->private_key, handle->private_key_length,
                                   other_public_key, other_public_key_length)))
    {
      tr_dh_secret_align (ret, my_secret_key_length);
    }
  else
    {
      tr_dh_secret_free (ret);
      ret = NULL;
    }

  return ret;
}

/***
****
***/

bool
tr_rand_buffer (void   * buffer,
                size_t   length)
{
  bool ret;
  tr_lock * rng_lock = get_rng_lock ();

  assert (buffer != NULL);

  tr_lockLock (rng_lock);
  ret = check_result (API (RNG_GenerateBlock) (get_rng (), buffer, length));
  tr_lockUnlock (rng_lock);

  return ret;
}