uint32_t throughput;
};
-/**
- * Structure used during a Key eXchange.
- */
-struct CadetTunnelKXCtx
-{
- /**
- * Encryption ("our") old "confirmed" key, for encrypting traffic sent by us
- * end before the key exchange is finished or times out.
- */
- struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
-
- /**
- * Decryption ("their") old "confirmed" key, for decrypting traffic sent by
- * the other end before the key exchange started.
- */
- struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
-
- /**
- * Same as @c e_key_old, for the case of two simultaneous KX.
- * This can happen if cadet decides to start a re-key while the peer has also
- * started its re-key (due to network delay this is impossible to avoid).
- * In this case, the key material generated with the peer's old ephemeral
- * *might* (but doesn't have to) be incorrect.
- * Since no more than two re-keys can happen simultaneously, this is enough.
- */
- struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old2;
-
- /**
- * Same as @c d_key_old, for the case described in @c e_key_old2.
- */
- struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old2;
-
- /**
- * Challenge to send and expect in the PONG.
- */
- uint32_t challenge;
-
- /**
- * When the rekey started. One minute after this the new key will be used.
- */
- struct GNUNET_TIME_Absolute rekey_start_time;
-
- /**
- * Task for delayed destruction of the Key eXchange context, to allow delayed
- * messages with the old key to be decrypted successfully.
- */
- struct GNUNET_SCHEDULER_Task *finish_task;
-};
/**
* Encryption systems possible.
/**
* Default Axolotl system.
*/
- CADET_Axolotl,
+ CADET_Axolotl
- /**
- * Fallback OTR-style encryption.
- */
- CADET_OTR
};
/**
*/
enum CadetTunnelEState estate;
- /**
- * Key eXchange context.
- */
- struct CadetTunnelKXCtx *kx_ctx;
-
/**
* Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
* key changes.
/**
* Task to start the rekey process.
*/
- struct GNUNET_SCHEDULER_Task * rekey_task;
+ struct GNUNET_SCHEDULER_Task *rekey_task;
/**
* Paths that are actively used to reach the destination peer.
*/
static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
-/**
- * Default TTL for payload packets.
- */
-static unsigned long long default_ttl;
-
/**
* Own Peer ID private key.
*/
static struct GNUNET_TIME_Relative ratchet_time;
-/******************************** OTR ***********************************/
-
-/**
- * Own global OTR ephemeral private key.
- */
-static struct GNUNET_CRYPTO_EcdhePrivateKey *otr_ephemeral_key;
-
-/**
- * Cached message used to perform a OTR key exchange.
- */
-static struct GNUNET_CADET_KX_Ephemeral otr_kx_msg;
-
-/**
- * Task to generate a new OTR ephemeral key.
- */
-static struct GNUNET_SCHEDULER_Task *rekey_task;
-
-/**
- * OTR Rekey period.
- */
-static struct GNUNET_TIME_Relative rekey_period;
-
-
/******************************************************************************/
/******************************** STATIC ***********************************/
/******************************************************************************/
}
-/**
- * Check if a key is invalid (NULL pointer or all 0)
- *
- * @param key Key to check.
- *
- * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
- */
-static int
-is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
-{
- struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
-
- if (NULL == key)
- return GNUNET_YES;
-
- memset (&null_key, 0, sizeof (null_key));
- if (0 == memcmp (key, &null_key, sizeof (null_key)))
- return GNUNET_YES;
- return GNUNET_NO;
-}
-
-
-/**
- * Ephemeral key message purpose size.
- *
- * @return Size of the part of the ephemeral key message that must be signed.
- */
-static size_t
-ephemeral_purpose_size (void)
-{
- return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
- sizeof (struct GNUNET_TIME_AbsoluteNBO) +
- sizeof (struct GNUNET_TIME_AbsoluteNBO) +
- sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
- sizeof (struct GNUNET_PeerIdentity);
-}
-
-
-/**
- * Size of the encrypted part of a ping message.
- *
- * @return Size of the encrypted part of a ping message.
- */
-static size_t
-ping_encryption_size (void)
-{
- return sizeof (uint32_t);
-}
-
-
/**
* Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
*
}
-/**
- * Check that a ephemeral key message s well formed and correctly signed.
- *
- * @param t Tunnel on which the message came.
- * @param msg The ephemeral key message.
- *
- * @return #GNUNET_OK if message is fine, #GNUNET_SYSERR otherwise.
- */
-int
-check_ephemeral (struct CadetTunnel *t,
- const struct GNUNET_CADET_KX_Ephemeral *msg)
-{
- /* Check message size */
- if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
- {
- /* This is probably an old "MESH" version. */
- LOG (GNUNET_ERROR_TYPE_INFO,
- "Expected ephemeral of size %u, got %u\n",
- sizeof (struct GNUNET_CADET_KX_Ephemeral),
- ntohs (msg->header.size));
- return GNUNET_SYSERR;
- }
-
- /* Check signature size */
- if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
- {
- LOG (GNUNET_ERROR_TYPE_WARNING,
- "Expected signature purpose of size %u, got %u\n",
- ephemeral_purpose_size (),
- ntohs (msg->purpose.size));
- return GNUNET_SYSERR;
- }
-
- /* Check origin */
- if (0 != memcmp (&msg->origin_identity,
- GCP_get_id (t->peer),
- sizeof (struct GNUNET_PeerIdentity)))
- {
- LOG (GNUNET_ERROR_TYPE_WARNING,
- "Unexpected origin, got %s\n",
- GNUNET_i2s (&msg->origin_identity));
- return GNUNET_SYSERR;
- }
-
- /* Check signature */
- if (GNUNET_OK !=
- GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
- &msg->purpose,
- &msg->signature,
- &msg->origin_identity.public_key))
- {
- LOG (GNUNET_ERROR_TYPE_WARNING, "Signature invalid\n");
- return GNUNET_SYSERR;
- }
-
- return GNUNET_OK;
-}
-
-
-/**
- * Select the best key to use for encryption (send), based on KX status.
- *
- * Normally, return the current key. If there is a KX in progress and the old
- * key is fresh enough, return the old key.
- *
- * @param t Tunnel to choose the key from.
- *
- * @return The optimal key to encrypt/hmac outgoing traffic.
- */
-static const struct GNUNET_CRYPTO_SymmetricSessionKey *
-select_key (const struct CadetTunnel *t)
-{
- const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
-
- if (NULL != t->kx_ctx
- && NULL == t->kx_ctx->finish_task)
- {
- struct GNUNET_TIME_Relative age;
-
- age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- " key exchange in progress, started %s ago\n",
- GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
- // FIXME make duration of old keys configurable
- if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
- {
- LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
- key = &t->kx_ctx->e_key_old;
- }
- else
- {
- LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
- key = &t->e_key;
- }
- }
- else
- {
- LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
- key = &t->e_key;
- }
- return key;
-}
-
-
/**
* Create a new Axolotl ephemeral (ratchet) key.
*
}
-/**
- * Encrypt daforce_newest_keyta with the tunnel key.
- *
- * @param t Tunnel whose key to use.
- * @param dst Destination for the encrypted data.
- * @param src Source of the plaintext. Can overlap with @c dst.
- * @param size Size of the plaintext.
- * @param iv Initialization Vector to use.
- * @param force_newest_key Force the use of the newest key, otherwise
- * CADET will use the old key when allowed.
- * This can happen in the case when a KX is going on
- * and the old one hasn't expired.
- */
-static int
-t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
- size_t size, uint32_t iv, int force_newest_key)
-{
- struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
- const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
- size_t out_size;
-
- LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
-
- key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
- #if DUMP_KEYS_TO_STDERR
- LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) key));
- #endif
- GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
- LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
- out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
- LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
-
- return out_size;
-}
-
-
/**
* Perform a HMAC.
*
}
-/**
- * Decrypt and verify data with the appropriate tunnel key.
- *
- * @param key Key to use.
- * @param dst Destination for the plaintext.
- * @param src Source of the encrypted data. Can overlap with @c dst.
- * @param size Size of the encrypted data.
- * @param iv Initialization Vector to use.
- *
- * @return Size of the decrypted data, -1 if an error was encountered.
- */
-static int
-decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
- void *dst, const void *src, size_t size, uint32_t iv)
-{
- struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
- size_t out_size;
-
- LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
- LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
- GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
- LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
- out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
- LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
-
- return out_size;
-}
-
-
-/**
- * Decrypt and verify data with the most recent tunnel key.
- *
- * @param t Tunnel whose key to use.
- * @param dst Destination for the plaintext.
- * @param src Source of the encrypted data. Can overlap with @c dst.
- * @param size Size of the encrypted data.
- * @param iv Initialization Vector to use.
- *
- * @return Size of the decrypted data, -1 if an error was encountered.
- */
-static int
-t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
- size_t size, uint32_t iv)
-{
- size_t out_size;
-
-#if DUMP_KEYS_TO_STDERR
- LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
-#endif
- if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
- {
- GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
- LOG (GNUNET_ERROR_TYPE_WARNING,
- "got data on %s without a valid key\n",
- GCT_2s (t));
- GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
- return -1;
- }
-
- out_size = decrypt (&t->d_key, dst, src, size, iv);
-
- return out_size;
-}
-
-
-/**
- * Decrypt and verify data with the appropriate tunnel key and verify that the
- * data has not been altered since it was sent by the remote peer.
- *
- * @param t Tunnel whose key to use.
- * @param dst Destination for the plaintext.
- * @param src Source of the encrypted data. Can overlap with @c dst.
- * @param size Size of the encrypted data.
- * @param iv Initialization Vector to use.
- * @param msg_hmac HMAC of the message, cannot be NULL.
- *
- * @return Size of the decrypted data, -1 if an error was encountered.
- */
-static int
-t_decrypt_and_validate (struct CadetTunnel *t,
- void *dst, const void *src,
- size_t size, uint32_t iv,
- const struct GNUNET_CADET_Hash *msg_hmac)
-{
- struct GNUNET_CRYPTO_SymmetricSessionKey *key;
- struct GNUNET_CADET_Hash hmac;
- int decrypted_size;
-
- /* Try primary (newest) key */
- key = &t->d_key;
- decrypted_size = decrypt (key, dst, src, size, iv);
- t_hmac (src, size, iv, key, &hmac);
- if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
- return decrypted_size;
-
- /* If no key exchange is going on, we just failed. */
- if (NULL == t->kx_ctx)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- "Failed checksum validation on tunnel %s with no KX\n",
- GCT_2s (t));
- GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
- return -1;
- }
-
- /* Try secondary key, from previous KX period. */
- key = &t->kx_ctx->d_key_old;
- decrypted_size = decrypt (key, dst, src, size, iv);
- t_hmac (src, size, iv, key, &hmac);
- if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
- return decrypted_size;
-
- /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
- key = &t->kx_ctx->d_key_old2;
- decrypted_size = decrypt (key, dst, src, size, iv);
- t_hmac (src, size, iv, key, &hmac);
- if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
- return decrypted_size;
-
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- "Failed checksum validation on tunnel %s with KX\n",
- GCT_2s (t));
- GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
- return -1;
-}
-
-
/**
* Decrypt and verify data with the appropriate tunnel key and verify that the
* data has not been altered since it was sent by the remote peer.
Np = ntohl (plaintext_header.Ns);
PNp = ntohl (plaintext_header.PNs);
}
- LOG (GNUNET_ERROR_TYPE_INFO, " got AX Nr %u\n", Np);
- if (Np != ax->Nr)
- if (GNUNET_OK != store_ax_keys (t, &ax->HKr, Np))
- /* Try the skipped keys, if that fails, we're out of luck. */
- return try_old_ax_keys (t, dst, src, size);
-
- osize = t_ax_decrypt (t, dst, &src[1], esize);
- ax->Nr = Np + 1;
-
- if (osize != esize)
- {
- GNUNET_break_op (0);
- return -1;
- }
-
- return osize;
-}
-
-
-/**
- * Create key material by doing ECDH on the local and remote ephemeral keys.
- *
- * @param key_material Where to store the key material.
- * @param ephemeral Peer's public ephemeral key.
- *
- * @return GNUNET_OK if it went fine, GNUNET_SYSERR otherwise.
- */
-static int
-derive_otr_key_material (struct GNUNET_HashCode *key_material,
- const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
-{
- if (GNUNET_OK !=
- GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key, ephemeral, key_material))
- {
- GNUNET_break (0);
- return GNUNET_SYSERR;
- }
- return GNUNET_OK;
-}
-
-
-/**
- * Create a symmetic key from the identities of both ends and the key material
- * from ECDH.
- *
- * @param key Destination for the generated key.
- * @param sender ID of the peer that will encrypt with @c key.
- * @param receiver ID of the peer that will decrypt with @c key.
- * @param key_material Hash created with ECDH with the ephemeral keys.
- */
-void
-derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
- const struct GNUNET_PeerIdentity *sender,
- const struct GNUNET_PeerIdentity *receiver,
- const struct GNUNET_HashCode *key_material)
-{
- const char salt[] = "CADET kx salt";
-
- GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
- salt, sizeof (salt),
- key_material, sizeof (struct GNUNET_HashCode),
- sender, sizeof (struct GNUNET_PeerIdentity),
- receiver, sizeof (struct GNUNET_PeerIdentity),
- NULL);
-}
-
-
-/**
- * Derive the tunnel's keys using our own and the peer's ephemeral keys.
- *
- * @param t Tunnel for which to create the keys.
- *
- * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
- */
-static int
-create_otr_keys (struct CadetTunnel *t)
-{
- struct GNUNET_HashCode km;
-
- if (GNUNET_OK != derive_otr_key_material (&km, &t->peers_ephemeral_key))
- return GNUNET_SYSERR;
- derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
- derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
- #if DUMP_KEYS_TO_STDERR
- LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
- LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
- LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
- LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
- LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
- #endif
- return GNUNET_OK;
-}
-
-
-/**
- * Create a new Key eXchange context for the tunnel.
- *
- * If the old keys were verified, keep them for old traffic. Create a new KX
- * timestamp and a new nonce.
- *
- * @param t Tunnel for which to create the KX ctx.
- *
- * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
- */
-static int
-create_kx_ctx (struct CadetTunnel *t)
-{
- LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
-
- if (NULL != t->kx_ctx)
- {
- if (NULL != t->kx_ctx->finish_task)
- {
- LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
- GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
- t->kx_ctx->finish_task = NULL;
- }
- }
- else
- {
- t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
- t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
- UINT32_MAX);
- }
-
- if (CADET_TUNNEL_KEY_OK == t->estate)
- {
- LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
- t->kx_ctx->d_key_old = t->d_key;
- t->kx_ctx->e_key_old = t->e_key;
- }
- else
- LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
- t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
- return create_otr_keys (t);
-}
-
-
-/**
- * @brief Finish the Key eXchange and destroy the old keys.
- *
- * @param cls Closure (Tunnel for which to finish the KX).
- */
-static void
-finish_kx (void *cls)
-{
- struct CadetTunnel *t = cls;
-
- LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
- GNUNET_free (t->kx_ctx);
- t->kx_ctx = NULL;
-}
-
-
-/**
- * Destroy a Key eXchange context for the tunnel. This function only schedules
- * the destruction, the freeing of the memory (and clearing of old key material)
- * happens after a delay!
- *
- * @param t Tunnel whose KX ctx to destroy.
- */
-static void
-destroy_kx_ctx (struct CadetTunnel *t)
-{
- struct GNUNET_TIME_Relative delay;
+ LOG (GNUNET_ERROR_TYPE_INFO, " got AX Nr %u\n", Np);
+ if (Np != ax->Nr)
+ if (GNUNET_OK != store_ax_keys (t, &ax->HKr, Np))
+ /* Try the skipped keys, if that fails, we're out of luck. */
+ return try_old_ax_keys (t, dst, src, size);
- if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
- return;
+ osize = t_ax_decrypt (t, dst, &src[1], esize);
+ ax->Nr = Np + 1;
- if (is_key_null (&t->kx_ctx->e_key_old))
+ if (osize != esize)
{
- t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (&finish_kx, t);
- return;
+ GNUNET_break_op (0);
+ return -1;
}
- delay = GNUNET_TIME_relative_divide (rekey_period, 4);
- delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
-
- t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay,
- &finish_kx, t);
+ return osize;
}
-
/**
* Pick a connection on which send the next data message.
*
* @param existing_q In case this a transmission of previously queued data,
* this should be TunnelQueue given to the client.
* Otherwise, NULL.
- *
* @return Handle to cancel message.
* NULL if @c cont is NULL or an error happens and message is dropped.
*/
static struct CadetTunnelQueue *
send_prebuilt_message (const struct GNUNET_MessageHeader *message,
- struct CadetTunnel *t, struct CadetConnection *c,
- int force, GCT_sent cont, void *cont_cls,
+ struct CadetTunnel *t,
+ struct CadetConnection *c,
+ int force,
+ GCT_sent cont,
+ void *cont_cls,
struct CadetTunnelQueue *existing_q)
{
struct GNUNET_MessageHeader *msg;
- struct GNUNET_CADET_Encrypted *otr_msg;
struct GNUNET_CADET_AX *ax_msg;
struct CadetTunnelQueue *tq;
size_t size = ntohs (message->size);
- const uint16_t max_overhead = sizeof (struct GNUNET_CADET_Encrypted)
- + sizeof (struct GNUNET_CADET_AX);
- char cbuf[max_overhead + size];
+ char cbuf[sizeof (struct GNUNET_CADET_AX) + size] GNUNET_ALIGN;
size_t esize;
uint32_t mid;
- uint32_t iv;
uint16_t type;
int fwd;
GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
- if (CADET_Axolotl == t->enc_type)
- {
- ax_msg = (struct GNUNET_CADET_AX *) cbuf;
- msg = &ax_msg->header;
- msg->size = htons (sizeof (struct GNUNET_CADET_AX) + size);
- msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_AX);
- ax_msg->reserved = 0;
- esize = t_ax_encrypt (t, &ax_msg[1], message, size);
- ax_msg->Ns = htonl (t->ax->Ns++);
- ax_msg->PNs = htonl (t->ax->PNs);
- GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
- t_h_encrypt (t, ax_msg);
- t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
- }
- else
- {
- otr_msg = (struct GNUNET_CADET_Encrypted *) cbuf;
- msg = &otr_msg->header;
- iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
- otr_msg->iv = iv;
- esize = t_encrypt (t, &otr_msg[1], message, size, iv, GNUNET_NO);
- t_hmac (&otr_msg[1], size, iv, select_key (t), &otr_msg->hmac);
- msg->size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
- msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
- otr_msg->ttl = htonl (default_ttl);
- }
+ GNUNET_assert (CADET_Axolotl == t->enc_type);
+ ax_msg = (struct GNUNET_CADET_AX *) cbuf;
+ msg = &ax_msg->header;
+ msg->size = htons (sizeof (struct GNUNET_CADET_AX) + size);
+ msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_AX);
+ esize = t_ax_encrypt (t, &ax_msg[1], message, size);
+ ax_msg->Ns = htonl (t->ax->Ns++);
+ ax_msg->PNs = htonl (t->ax->PNs);
+ GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
+ t_h_encrypt (t, ax_msg);
+ t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
GNUNET_assert (esize == size);
if (NULL == c)
}
-/**
- * Callback called when a queued message is sent.
- *
- * @param cls Closure.
- * @param c Connection this message was on.
- * @param type Type of message sent.
- * @param fwd Was this a FWD going message?
- * @param size Size of the message.
- */
-static void
-pong_sent (void *cls,
- struct CadetConnection *c,
- struct CadetConnectionQueue *q,
- uint16_t type, int fwd, size_t size)
-{
- struct CadetTunnel *t = cls;
- LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
-
- t->pong_h = NULL;
-}
-
-
/**
* Sends key exchange message on a tunnel, choosing the best connection.
* Should not be called on loopback tunnels.
}
switch (type)
{
- case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
GNUNET_assert (NULL == t->ephm_h);
cont = &ephm_sent;
break;
- case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
- GNUNET_assert (NULL == t->pong_h);
- cont = &pong_sent;
- break;
-
default:
LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
GNUNET_assert (0);
}
-/**
- * Send the ephemeral key on a tunnel.
- *
- * @param t Tunnel on which to send the key.
- */
-static void
-send_ephemeral (struct CadetTunnel *t)
-{
- LOG (GNUNET_ERROR_TYPE_INFO, "==> EPHM for %s\n", GCT_2s (t));
- if (NULL != t->ephm_h)
- {
- LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
- return;
- }
-
- otr_kx_msg.sender_status = htonl (t->estate);
- otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
- otr_kx_msg.nonce = t->kx_ctx->challenge;
- LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
- t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
- ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
- LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
- t->ephm_h = send_kx (t, &otr_kx_msg.header);
-}
-
-
-/**
- * Send a pong message on a tunnel.
- *d_
- * @param t Tunnel on which to send the pong.
- * @param challenge Value sent in the ping that we have to send back.
- */
-static void
-send_pong (struct CadetTunnel *t, uint32_t challenge)
-{
- struct GNUNET_CADET_KX_Pong msg;
-
- LOG (GNUNET_ERROR_TYPE_INFO, "==> PONG for %s\n", GCT_2s (t));
- if (NULL != t->pong_h)
- {
- LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
- return;
- }
- msg.header.size = htons (sizeof (msg));
- msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
- msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
- msg.nonce = challenge;
- LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
- t_encrypt (t, &msg.nonce, &msg.nonce,
- sizeof (msg.nonce), msg.iv, GNUNET_YES);
- LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
-
- t->pong_h = send_kx (t, &msg.header);
-}
-
-
-/**
- * Initiate a rekey with the remote peer.
- *
- * @param cls Closure (tunnel).
- */
-static void
-rekey_tunnel (void *cls)
-{
- struct CadetTunnel *t = cls;
-
- t->rekey_task = NULL;
- LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
- GNUNET_assert (NULL != t->kx_ctx);
- struct GNUNET_TIME_Relative duration;
-
- duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- " kx started %s ago\n",
- GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
-
- // FIXME make duration of old keys configurable
- if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
- {
- LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
- memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
- memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
- }
-
- send_ephemeral (t);
-
- switch (t->estate)
- {
- case CADET_TUNNEL_KEY_UNINITIALIZED:
- GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
- break;
-
- case CADET_TUNNEL_KEY_SENT:
- break;
-
- case CADET_TUNNEL_KEY_OK:
- /* Inconsistent!
- * - state should have changed during rekey_iterator
- * - task should have been canceled at pong_handle
- */
- GNUNET_break (0);
- GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
- break;
-
- case CADET_TUNNEL_KEY_PING:
- case CADET_TUNNEL_KEY_REKEY:
- break;
-
- default:
- LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
- }
-
- // FIXME exponential backoff
- struct GNUNET_TIME_Relative delay;
-
- delay = GNUNET_TIME_relative_divide (rekey_period, 16);
- delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
- LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
- GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
- t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
-}
-
-
-/**
- * Our ephemeral key has changed, create new session key on all tunnels.
- *
- * Each tunnel will start the Key Exchange with a random delay between
- * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
- * per second, on average.
- *
- * @param cls Closure (size of the hashmap).
- * @param key Current public key.
- * @param value Value in the hash map (tunnel).
- *
- * @return #GNUNET_YES, so we should continue to iterate,
- */
-static int
-rekey_iterator (void *cls,
- const struct GNUNET_PeerIdentity *key,
- void *value)
-{
- struct CadetTunnel *t = value;
- struct GNUNET_TIME_Relative delay;
- long n = (long) cls;
- uint32_t r;
-
- if (NULL != t->rekey_task)
- return GNUNET_YES;
-
- if (GNUNET_YES == GCT_is_loopback (t))
- return GNUNET_YES;
-
- if (CADET_OTR != t->enc_type)
- return GNUNET_YES;
-
- r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
- delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
- t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
- if (GNUNET_OK == create_kx_ctx (t))
- GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
- else
- {
- GNUNET_break (0);
- // FIXME restart kx
- }
-
- return GNUNET_YES;
-}
-
-
-/**
- * Create a new ephemeral key and key message, schedule next rekeying.
- *
- * @param cls Closure (unused).
- */
-static void
-global_otr_rekey (void *cls)
-{
- struct GNUNET_TIME_Absolute time;
- long n;
-
- rekey_task = NULL;
- GNUNET_free_non_null (otr_ephemeral_key);
- otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
-
- time = GNUNET_TIME_absolute_get ();
- otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
- time = GNUNET_TIME_absolute_add (time, rekey_period);
- time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
- otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
- GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
- LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
-
- GNUNET_assert (GNUNET_OK ==
- GNUNET_CRYPTO_eddsa_sign (id_key,
- &otr_kx_msg.purpose,
- &otr_kx_msg.signature));
-
- n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
- GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
-
- rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
- &global_otr_rekey, NULL);
-}
-
-
/**
* Called only on shutdown, destroy every tunnel.
*
}
-/**
- * The peer's ephemeral key has changed: update the symmetrical keys.
- *
- * @param t Tunnel this message came on.
- * @param msg Key eXchange message.
- */
-static void
-handle_ephemeral (struct CadetTunnel *t,
- const struct GNUNET_CADET_KX_Ephemeral *msg)
-{
- LOG (GNUNET_ERROR_TYPE_INFO, "<== EPHM for %s\n", GCT_2s (t));
-
- /* Some old versions are still around, don't log as error. */
- if (GNUNET_OK != check_ephemeral (t, msg))
- return;
-
- /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
- if (NULL != t->ax)
- {
- destroy_ax (t);
- t->enc_type = CADET_OTR;
- if (NULL != t->rekey_task)
- GNUNET_SCHEDULER_cancel (t->rekey_task);
- if (GNUNET_OK != create_kx_ctx (t))
- {
- // FIXME restart kx
- GNUNET_break (0);
- return;
- }
- rekey_tunnel (t);
- GNUNET_STATISTICS_update (stats, "# otr-downgrades", -1, GNUNET_NO);
- }
-
- /**
- * If the key is different from what we know, derive the new E/D keys.
- * Else destroy the rekey ctx (duplicate EPHM after successful KX).
- */
- if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
- sizeof (msg->ephemeral_key)))
- {
- #if DUMP_KEYS_TO_STDERR
- LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
- LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &msg->ephemeral_key));
- #endif
- t->peers_ephemeral_key = msg->ephemeral_key;
-
- if (GNUNET_OK != create_kx_ctx (t))
- {
- // FIXME restart kx
- GNUNET_break (0);
- return;
- }
-
- if (CADET_TUNNEL_KEY_OK == t->estate)
- {
- GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
- }
- if (NULL != t->rekey_task)
- GNUNET_SCHEDULER_cancel (t->rekey_task);
- t->rekey_task = GNUNET_SCHEDULER_add_now (&rekey_tunnel, t);
- }
- if (CADET_TUNNEL_KEY_SENT == t->estate)
- {
- LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
- send_ephemeral (t);
- GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
- }
-
- if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
- {
- uint32_t nonce;
-
- LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
- t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
- LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
- send_pong (t, nonce);
- }
-}
-
-
-/**
- * Peer has answer to our challenge.
- * If answer is successful, consider the key exchange finished and clean
- * up all related state.
- *
- * @param t Tunnel this message came on.
- * @param msg Key eXchange Pong message.
- */
-static void
-handle_pong (struct CadetTunnel *t,
- const struct GNUNET_CADET_KX_Pong *msg)
-{
- uint32_t challenge;
-
- LOG (GNUNET_ERROR_TYPE_INFO, "<== PONG for %s\n", GCT_2s (t));
- if (NULL == t->rekey_task)
- {
- GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
- return;
- }
- if (NULL == t->kx_ctx)
- {
- GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
- return;
- }
-
- t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
- if (challenge != t->kx_ctx->challenge)
- {
- LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
- LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
- challenge, msg->nonce, t->kx_ctx->challenge);
- send_ephemeral (t);
- return;
- }
- GNUNET_SCHEDULER_cancel (t->rekey_task);
- t->rekey_task = NULL;
-
- /* Don't free the old keys right away, but after a delay.
- * Rationale: the KX could have happened over a very fast connection,
- * with payload traffic still signed with the old key stuck in a slower
- * connection.
- * Don't keep the keys longer than 1/4 the rekey period, and no longer than
- * one minute.
- */
- destroy_kx_ctx (t);
- GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
-}
-
-
/**
* Handle Axolotl handshake.
*
if (NULL == t->ax)
{
/* Something is wrong if ax is NULL. Whose fault it is? */
- GNUNET_break_op (CADET_OTR == t->enc_type);
GNUNET_break (CADET_Axolotl == t->enc_type);
return;
}
type = ntohs (msg->type);
switch (type)
{
- case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
- {
- const struct GNUNET_CADET_Encrypted *emsg;
- size_t payload_size;
-
- GNUNET_STATISTICS_update (stats, "# received OTR", 1, GNUNET_NO);
- emsg = (const struct GNUNET_CADET_Encrypted *) msg;
- payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
- decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
- emsg->iv, &emsg->hmac);
- }
- break;
case GNUNET_MESSAGE_TYPE_CADET_AX:
{
const struct GNUNET_CADET_AX *emsg;
GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
switch (type)
{
- case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
- handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
- break;
-
- case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
- handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
- break;
-
case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
break;
-
default:
GNUNET_break_op (0);
LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
{
- int expected_overhead;
+ unsigned int expected_overhead;
LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
expected_overhead = 0;
- expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
+ expected_overhead += sizeof (struct GNUNET_CADET_AX);
expected_overhead += sizeof (struct GNUNET_CADET_Data);
expected_overhead += sizeof (struct GNUNET_CADET_ACK);
GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
if (GNUNET_OK !=
- GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
- &default_ttl))
- {
- GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_DEBUG,
- "CADET", "DEFAULT_TTL", "USING DEFAULT");
- default_ttl = 64;
- }
- if (GNUNET_OK !=
- GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
- &rekey_period))
- {
- rekey_period = GNUNET_TIME_UNIT_DAYS;
- }
- if (GNUNET_OK !=
- GNUNET_CONFIGURATION_get_value_number (c, "CADET", "RATCHET_MESSAGES",
+ GNUNET_CONFIGURATION_get_value_number (c,
+ "CADET",
+ "RATCHET_MESSAGES",
&ratchet_messages))
{
GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
- "CADET", "RATCHET_MESSAGES", "USING DEFAULT");
+ "CADET",
+ "RATCHET_MESSAGES",
+ "USING DEFAULT");
ratchet_messages = 64;
}
if (GNUNET_OK !=
- GNUNET_CONFIGURATION_get_value_time (c, "CADET", "RATCHET_TIME",
+ GNUNET_CONFIGURATION_get_value_time (c,
+ "CADET",
+ "RATCHET_TIME",
&ratchet_time))
{
GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
id_key = key;
-
- otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
- otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
- otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
- otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
- otr_kx_msg.origin_identity = my_full_id;
- rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
}
GCT_shutdown (void)
{
LOG (GNUNET_ERROR_TYPE_DEBUG, "Shutting down tunnels\n");
- if (NULL != rekey_task)
- {
- GNUNET_SCHEDULER_cancel (rekey_task);
- rekey_task = NULL;
- }
GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
GNUNET_CONTAINER_multipeermap_destroy (tunnels);
}
GNUNET_SCHEDULER_cancel (t->rekey_task);
t->rekey_task = NULL;
}
- if (NULL != t->kx_ctx)
- {
- if (NULL != t->kx_ctx->finish_task)
- GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
- GNUNET_free (t->kx_ctx);
- }
-
if (NULL != t->ax)
destroy_ax (t);
LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
LOG2 (level, "TTT cstate %s, estate %s\n",
cstate2s (t->cstate), estate2s (t->estate));
- LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
- t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
#if DUMP_KEYS_TO_STDERR
if (CADET_Axolotl == t->enc_type)
{
}
else
{
- LOG2 (level, "TTT my EPHM\t %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
LOG2 (level, "TTT peers EPHM:\t %s\n",
GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
LOG2 (level, "TTT ENC key:\t %s\n",
GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
LOG2 (level, "TTT DEC key:\t %s\n",
GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
- if (t->kx_ctx)
- {
- LOG2 (level, "TTT OLD ENC key:\t %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->e_key_old));
- LOG2 (level, "TTT OLD DEC key:\t %s\n",
- GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->d_key_old));
- }
}
#endif
LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
projects / oweals / gnunet.git / commitdiff