#include "gnunet_protocols.h"
#include "core.h"
+
/**
* How long do we wait for SET_KEY confirmation initially?
*/
*/
#define MIN_PING_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
+/**
+ * How often do we rekey?
+ */
+#define REKEY_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 90)
+
+
/**
* What is the maximum age of a message for us to consider processing
* it? Note that this looks at the timestamp used by the other peer,
};
GNUNET_NETWORK_STRUCT_END
+
+
/**
* Number of bytes (at the beginning) of "struct EncryptedMessage"
* that are NOT encrypted.
* encrypted with his session key (which we got). Key exchange
* is done.
*/
- KX_STATE_UP
+ KX_STATE_UP,
+
+ /**
+ * We're rekeying, so we have received the other peer's session
+ * key, but he didn't get ours yet.
+ */
+ KX_STATE_REKEY,
+
+ /**
+ * We're rekeying but have not yet received confirmation for our new
+ * key from the other peer.
+ */
+ KX_STATE_REKEY_SENT
};
};
-
/**
* Handle to peerinfo service.
*/
static struct GNUNET_SERVER_MessageStreamTokenizer *mst;
-
/**
* Derive an authentication key from "set key" information
+ *
+ * @param akey authentication key to derive
+ * @param skey session key to use
+ * @param seed seed to use
+ * @param creation_time creation time to use
*/
static void
derive_auth_key (struct GNUNET_CRYPTO_AuthKey *akey,
static const char ctx[] = "authentication key";
struct GNUNET_TIME_AbsoluteNBO ctbe;
-
ctbe = GNUNET_TIME_absolute_hton (creation_time);
GNUNET_CRYPTO_hmac_derive_key (akey, skey, &seed, sizeof (seed), &skey->key,
sizeof (skey->key), &ctbe, sizeof (ctbe), ctx,
/**
* Derive an IV from packet information
+ *
+ * @param iv initialization vector to initialize
+ * @param skey session key to use
+ * @param seed seed to use
+ * @param creation_time creation time to use
*/
static void
derive_iv (struct GNUNET_CRYPTO_AesInitializationVector *iv,
sizeof (ctx), NULL);
}
+
/**
* Derive an IV from pong packet information
+ *
+ * @param iv initialization vector to initialize
+ * @param skey session key to use
+ * @param seed seed to use
+ * @param creation_time creation time to use
+ * @param identity identity of the other peer to use
*/
static void
derive_pong_iv (struct GNUNET_CRYPTO_AesInitializationVector *iv,
&kx->encrypt_key, iv, out));
GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# bytes encrypted"), size,
GNUNET_NO);
-#if DEBUG_CORE > 2
+ /* the following is too sensitive to write to log files by accident,
+ so we require manual intervention to get this one... */
+#if 0
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Encrypted %u bytes for `%4s' using key %u, IV %u\n",
(unsigned int) size, GNUNET_i2s (&kx->peer),
}
-
-
/**
* Decrypt size bytes from in and write the result to out. Use the
* key for inbound traffic of the given neighbour. This function does
GNUNET_break (0);
return GNUNET_NO;
}
- if ((kx->status != KX_STATE_KEY_RECEIVED) && (kx->status != KX_STATE_UP))
+ if ( (kx->status != KX_STATE_KEY_RECEIVED) && (kx->status != KX_STATE_UP) &&
+ (kx->status != KX_STATE_REKEY_SENT) )
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# bytes decrypted"), size,
GNUNET_NO);
-#if DEBUG_CORE > 1
+ /* the following is too sensitive to write to log files by accident,
+ so we require manual intervention to get this one... */
+#if 0
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Decrypted %u bytes from `%4s' using key %u, IV %u\n",
(unsigned int) size, GNUNET_i2s (&kx->peer),
kx->pitr = NULL;
if (kx->public_key != NULL)
return; /* done here */
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Failed to obtain public key for peer `%4s', delaying processing of SET_KEY\n",
GNUNET_i2s (&kx->peer));
-#endif
GNUNET_STATISTICS_update (GSC_stats,
gettext_noop
("# Delayed connecting due to lack of public key"),
{
struct GSC_KeyExchangeInfo *kx;
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Initiating key exchange with `%s'\n",
GNUNET_i2s (pid));
-#endif
GNUNET_STATISTICS_update (GSC_stats,
gettext_noop ("# key exchanges initiated"), 1,
GNUNET_NO);
GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# session keys received"),
1, GNUNET_NO);
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Core service receives `%s' request from `%4s'.\n", "SET_KEY",
GNUNET_i2s (&kx->peer));
-#endif
if (kx->public_key == NULL)
{
GNUNET_free_non_null (kx->skm_received);
GNUNET_STATISTICS_update (GSC_stats,
gettext_noop ("# SET_KEY messages decrypted"), 1,
GNUNET_NO);
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received SET_KEY from `%s'\n",
GNUNET_i2s (&kx->peer));
-#endif
kx->decrypt_key = k;
if (kx->decrypt_key_created.abs_value != t.abs_value)
{
kx->decrypt_key_created = t;
}
sender_status = (enum KxStateMachine) ntohl (m->sender_status);
-
switch (kx->status)
{
case KX_STATE_DOWN:
case KX_STATE_KEY_RECEIVED:
/* we're not up, so we are already doing 'send_key' */
break;
- case KX_STATE_UP:
+ case KX_STATE_UP:
+ if ((sender_status == KX_STATE_DOWN) ||
+ (sender_status == KX_STATE_KEY_SENT))
+ send_key (kx); /* we are up, but other peer is not! */
+ break;
+ case KX_STATE_REKEY:
+ if ((sender_status == KX_STATE_DOWN) ||
+ (sender_status == KX_STATE_KEY_SENT))
+ send_key (kx); /* we are up, but other peer is not! */
+ break;
+ case KX_STATE_REKEY_SENT:
if ((sender_status == KX_STATE_DOWN) ||
(sender_status == KX_STATE_KEY_SENT))
send_key (kx); /* we are up, but other peer is not! */
GNUNET_STATISTICS_update (GSC_stats,
gettext_noop ("# PING messages received"), 1,
GNUNET_NO);
- if ((kx->status != KX_STATE_KEY_RECEIVED) && (kx->status != KX_STATE_UP))
+ if ((kx->status != KX_STATE_KEY_RECEIVED) && (kx->status != KX_STATE_UP) &&
+ (kx->status != KX_STATE_REKEY_SENT))
{
/* defer */
GNUNET_free_non_null (kx->ping_received);
return;
}
m = (const struct PingMessage *) msg;
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Core service receives `%s' request from `%4s'.\n", "PING",
GNUNET_i2s (&kx->peer));
-#endif
derive_iv (&iv, &kx->decrypt_key, m->iv_seed, &GSC_my_identity);
if (GNUNET_OK !=
do_decrypt (kx, &iv, &m->target, &t.target,
GNUNET_break_op (0);
return;
}
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received PING from `%s'\n",
GNUNET_i2s (&kx->peer));
-#endif
/* construct PONG */
tx.reserved = GNUNET_BANDWIDTH_VALUE_MAX;
tx.challenge = t.challenge;
kx->status = KX_STATE_DOWN;
return;
}
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending KEEPALIVE to `%s'\n",
GNUNET_i2s (&kx->peer));
-#endif
GNUNET_STATISTICS_update (GSC_stats,
gettext_noop ("# keepalive messages sent"), 1,
GNUNET_NO);
}
+/**
+ * Trigger rekeying event.
+ *
+ * @param cls the 'struct GSC_KeyExchangeInfo'
+ * @param tc schedule context (unused)
+ */
+static void
+trigger_rekey (void *cls,
+ const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ struct GSC_KeyExchangeInfo *kx = cls;
+
+ kx->status = KX_STATE_REKEY;
+ kx->set_key_retry_frequency = INITIAL_SET_KEY_RETRY_FREQUENCY;
+ kx->retry_set_key_task =
+ GNUNET_SCHEDULER_add_delayed (kx->set_key_retry_frequency,
+ &set_key_retry_task, kx);
+}
+
+
+/**
+ * Schedule rekey operation.
+ *
+ * @param kx key exchange to schedule rekey for
+ */
+static void
+schedule_rekey (struct GSC_KeyExchangeInfo *kx)
+{
+ struct GNUNET_TIME_Relative rdelay;
+
+ if (GNUNET_SCHEDULER_NO_TASK != kx->retry_set_key_task)
+ GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
+ rdelay = REKEY_FREQUENCY;
+ /* randomize rekey frequency by one minute to avoid synchronization */
+ rdelay.rel_value += GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
+ 60 * 1000);
+ kx->retry_set_key_task = GNUNET_SCHEDULER_add_delayed (REKEY_FREQUENCY,
+ &trigger_rekey,
+ kx);
+}
+
+
/**
* We received a PONG message. Validate and update our status.
*
GNUNET_STATISTICS_update (GSC_stats,
gettext_noop ("# PONG messages received"), 1,
GNUNET_NO);
- if ((kx->status != KX_STATE_KEY_RECEIVED) && (kx->status != KX_STATE_UP))
+ switch (kx->status)
{
- if (kx->status == KX_STATE_KEY_SENT)
- {
- GNUNET_free_non_null (kx->pong_received);
- kx->pong_received = (struct PongMessage *) GNUNET_copy_message (msg);
- }
+ case KX_STATE_DOWN:
+ return;
+ case KX_STATE_KEY_SENT:
+ GNUNET_free_non_null (kx->pong_received);
+ kx->pong_received = (struct PongMessage *) GNUNET_copy_message (msg);
+ return;
+ case KX_STATE_KEY_RECEIVED:
+ break;
+ case KX_STATE_UP:
+ break;
+ case KX_STATE_REKEY:
+ break;
+ case KX_STATE_REKEY_SENT:
+ break;
+ default:
+ GNUNET_break (0);
return;
}
m = (const struct PongMessage *) msg;
-#if DEBUG_HANDSHAKE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Core service receives `%s' response from `%4s'.\n", "PONG",
GNUNET_i2s (&kx->peer));
-#endif
/* mark as garbage, just to be sure */
memset (&t, 255, sizeof (t));
derive_pong_iv (&iv, &kx->decrypt_key, m->iv_seed, kx->ping_challenge,
|| (kx->ping_challenge != t.challenge))
{
/* PONG malformed */
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Received malformed `%s' wanted sender `%4s' with challenge %u\n",
"PONG", GNUNET_i2s (&kx->peer),
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Received malformed `%s' received from `%4s' with challenge %u\n",
"PONG", GNUNET_i2s (&t.target), (unsigned int) t.challenge);
-#endif
return;
}
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received PONG from `%s'\n",
GNUNET_i2s (&kx->peer));
-#endif
switch (kx->status)
{
case KX_STATE_DOWN:
GNUNET_NO);
kx->status = KX_STATE_UP;
GSC_SESSIONS_create (&kx->peer, kx);
- if (GNUNET_SCHEDULER_NO_TASK != kx->retry_set_key_task)
- {
- GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
- kx->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
- }
+ schedule_rekey (kx);
GNUNET_assert (kx->keep_alive_task == GNUNET_SCHEDULER_NO_TASK);
if (kx->emsg_received != NULL)
{
case KX_STATE_UP:
update_timeout (kx);
break;
+ case KX_STATE_REKEY:
+ update_timeout (kx);
+ break;
+ case KX_STATE_REKEY_SENT:
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop
+ ("# rekey operations confirmed via PONG"), 1,
+ GNUNET_NO);
+ kx->status = KX_STATE_UP;
+ schedule_rekey (kx);
+ update_timeout (kx);
+ break;
default:
GNUNET_break (0);
break;
if (kx->public_key == NULL)
{
/* lookup public key, then try again */
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Trying to obtain public key for `%s'\n",
GNUNET_i2s (&kx->peer));
-#endif
kx->pitr =
GNUNET_PEERINFO_iterate (peerinfo, &kx->peer,
GNUNET_TIME_UNIT_FOREVER_REL /* timeout? */ ,
case KX_STATE_UP:
GNUNET_break (0);
return;
+ case KX_STATE_REKEY:
+ kx->status = KX_STATE_REKEY_SENT;
+ /* setup fresh SET KEY message */
+ setup_fresh_setkey (kx);
+ setup_fresh_ping (kx);
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop
+ ("# SET_KEY and PING messages created"), 1,
+ GNUNET_NO);
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop
+ ("# REKEY operations performed"), 1,
+ GNUNET_NO);
+ break;
+ case KX_STATE_REKEY_SENT:
+ break;
default:
GNUNET_break (0);
return;
}
/* always update sender status in SET KEY message */
- kx->skm.sender_status = htonl ((int32_t) kx->status);
-#if DEBUG_CORE
+ /* Not sending rekey sent state to be compatible with GNUnet 0.9.2 */
+ kx->skm.sender_status = htonl ((int32_t) ((kx->status == KX_STATE_REKEY_SENT) ?
+ KX_STATE_KEY_RECEIVED : kx->status));
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending SET_KEY and PING to `%s'\n",
GNUNET_i2s (&kx->peer));
-#endif
GSC_NEIGHBOURS_transmit (&kx->peer, &kx->skm.header,
kx->set_key_retry_frequency);
GSC_NEIGHBOURS_transmit (&kx->peer, &kx->ping.header,
do_encrypt (kx, &iv, &ph->sequence_number,
&em->sequence_number,
used - ENCRYPTED_HEADER_SIZE));
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Encrypted %u bytes for %s\n",
used - ENCRYPTED_HEADER_SIZE, GNUNET_i2s (&kx->peer));
-#endif
derive_auth_key (&auth_key, &kx->encrypt_key, ph->iv_seed,
kx->encrypt_key_created);
GNUNET_CRYPTO_hmac (&auth_key, &em->sequence_number,
return;
}
m = (const struct EncryptedMessage *) msg;
- if ((kx->status != KX_STATE_KEY_RECEIVED) && (kx->status != KX_STATE_UP))
+ if ((kx->status != KX_STATE_KEY_RECEIVED) && (kx->status != KX_STATE_UP) &&
+ (kx->status != KX_STATE_REKEY_SENT) )
{
GNUNET_STATISTICS_update (GSC_stats,
gettext_noop
do_decrypt (kx, &iv, &m->sequence_number, &buf[ENCRYPTED_HEADER_SIZE],
size - ENCRYPTED_HEADER_SIZE))
return;
-#if DEBUG_CORE
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Decrypted %u bytes from %s\n",
size - ENCRYPTED_HEADER_SIZE, GNUNET_i2s (&kx->peer));
-#endif
pt = (struct EncryptedMessage *) buf;
/* validate sequence number */
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