+/*
+ This file is part of GNUnet.
+ (C) 2009, 2010, 2011, 2012 Christian Grothoff (and other contributing authors)
+
+ GNUnet is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published
+ by the Free Software Foundation; either version 3, or (at your
+ option) any later version.
+
+ GNUnet is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GNUnet; see the file COPYING. If not, write to the
+ Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file core/gnunet-service-core_kx.c
+ * @brief code for managing the key exchange (SET_KEY, PING, PONG) with other peers
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet-service-core_kx.h"
+#include "gnunet-service-core.h"
+#include "gnunet-service-core_clients.h"
+#include "gnunet-service-core_neighbours.h"
+#include "gnunet-service-core_sessions.h"
+#include "gnunet_statistics_service.h"
+#include "gnunet_peerinfo_service.h"
+#include "gnunet_hello_lib.h"
+#include "gnunet_constants.h"
+#include "gnunet_signatures.h"
+#include "gnunet_protocols.h"
+#include "core.h"
+
+
+/**
+ * Set to GNUNET_YES to perform some slightly expensive internal invariant checks.
+ */
+#define EXTRA_CHECKS GNUNET_YES
+
+/**
+ * How long do we wait for SET_KEY confirmation initially?
+ */
+#define INITIAL_SET_KEY_RETRY_FREQUENCY GNUNET_TIME_relative_multiply (MAX_SET_KEY_DELAY, 1)
+
+/**
+ * What is the minimum frequency for a PING message?
+ */
+#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,
+ * so clock skew between machines does come into play here. So this
+ * should be picked high enough so that a little bit of clock skew
+ * does not prevent peers from connecting to us.
+ */
+#define MAX_MESSAGE_AGE GNUNET_TIME_UNIT_DAYS
+
+/**
+ * What is the maximum delay for a SET_KEY message?
+ */
+#define MAX_SET_KEY_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 10)
+
+
+GNUNET_NETWORK_STRUCT_BEGIN
/**
* We're sending an (encrypted) PING to the other peer to check if he
};
-
/**
- * Response to a PING. Includes data from the original PING
- * plus initial bandwidth quota information.
+ * Response to a PING. Includes data from the original PING.
*/
struct PongMessage
{
uint32_t challenge GNUNET_PACKED;
/**
- * Desired bandwidth (how much we should send to this
- * peer / how much is the sender willing to receive).
+ * Reserved, always 'GNUNET_BANDWIDTH_VALUE_MAX'.
*/
- struct GNUNET_BANDWIDTH_Value32NBO inbound_bw_limit;
+ struct GNUNET_BANDWIDTH_Value32NBO reserved;
/**
* Intended target of the PING, used primarily to check
};
+/**
+ * Encapsulation for encrypted messages exchanged between
+ * peers. Followed by the actual encrypted data.
+ */
+struct EncryptedMessage
+{
+ /**
+ * Message type is either CORE_ENCRYPTED_MESSAGE.
+ */
+ struct GNUNET_MessageHeader header;
+
+ /**
+ * Random value used for IV generation.
+ */
+ uint32_t iv_seed GNUNET_PACKED;
+
+ /**
+ * MAC of the encrypted message (starting at 'sequence_number'),
+ * used to verify message integrity. Everything after this value
+ * (excluding this value itself) will be encrypted and authenticated.
+ * ENCRYPTED_HEADER_SIZE must be set to the offset of the *next* field.
+ */
+ struct GNUNET_HashCode hmac;
+
+ /**
+ * Sequence number, in network byte order. This field
+ * must be the first encrypted/decrypted field
+ */
+ uint32_t sequence_number GNUNET_PACKED;
+
+ /**
+ * Reserved, always 'GNUNET_BANDWIDTH_VALUE_MAX'.
+ */
+ struct GNUNET_BANDWIDTH_Value32NBO reserved;
+
+ /**
+ * Timestamp. Used to prevent reply of ancient messages
+ * (recent messages are caught with the sequence number).
+ */
+ struct GNUNET_TIME_AbsoluteNBO timestamp;
+
+};
+GNUNET_NETWORK_STRUCT_END
+
+
+/**
+ * Number of bytes (at the beginning) of "struct EncryptedMessage"
+ * that are NOT encrypted.
+ */
+#define ENCRYPTED_HEADER_SIZE (offsetof(struct EncryptedMessage, sequence_number))
+
+
+/**
+ * State machine for our P2P encryption handshake. Everyone starts in
+ * "DOWN", if we receive the other peer's key (other peer initiated)
+ * we start in state RECEIVED (since we will immediately send our
+ * own); otherwise we start in SENT. If we get back a PONG from
+ * within either state, we move up to CONFIRMED (the PONG will always
+ * be sent back encrypted with the key we sent to the other peer).
+ */
+enum KxStateMachine
+{
+ /**
+ * No handshake yet.
+ */
+ KX_STATE_DOWN,
+
+ /**
+ * We've sent our session key.
+ */
+ KX_STATE_KEY_SENT,
+
+ /**
+ * We've received the other peers session key.
+ */
+ KX_STATE_KEY_RECEIVED,
+
+ /**
+ * The other peer has confirmed our session key with a message
+ * encrypted with his session key (which we got). Key exchange
+ * is done.
+ */
+ 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
+};
+
+
+/**
+ * Information about the status of a key exchange with another peer.
+ */
+struct GSC_KeyExchangeInfo
+{
+ /**
+ * Identity of the peer.
+ */
+ struct GNUNET_PeerIdentity peer;
+
+ /**
+ * SetKeyMessage to transmit (initialized the first
+ * time our status goes past 'KX_STATE_KEY_SENT').
+ */
+ struct SetKeyMessage skm;
+
+ /**
+ * PING message we transmit to the other peer.
+ */
+ struct PingMessage ping;
+
+ /**
+ * SetKeyMessage we received and did not process yet.
+ */
+ struct SetKeyMessage *skm_received;
+
+ /**
+ * PING message we received from the other peer and
+ * did not process yet (or NULL).
+ */
+ struct PingMessage *ping_received;
+
+ /**
+ * PONG message we received from the other peer and
+ * did not process yet (or NULL).
+ */
+ struct PongMessage *pong_received;
+
+ /**
+ * Encrypted message we received from the other peer and
+ * did not process yet (or NULL).
+ */
+ struct EncryptedMessage *emsg_received;
+
+ /**
+ * Non-NULL if we are currently looking up HELLOs for this peer.
+ * for this peer.
+ */
+ struct GNUNET_PEERINFO_IteratorContext *pitr;
+
+ /**
+ * Public key of the neighbour, NULL if we don't have it yet.
+ */
+ struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *public_key;
+
+ /**
+ * We received a PONG message before we got the "public_key"
+ * (or the SET_KEY). We keep it here until we have a key
+ * to decrypt it. NULL if no PONG is pending.
+ */
+ struct PongMessage *pending_pong;
+
+ /**
+ * Key we use to encrypt our messages for the other peer
+ * (initialized by us when we do the handshake).
+ */
+ struct GNUNET_CRYPTO_AesSessionKey encrypt_key;
+
+ /**
+ * Key we use to decrypt messages from the other peer
+ * (given to us by the other peer during the handshake).
+ */
+ struct GNUNET_CRYPTO_AesSessionKey decrypt_key;
+
+ /**
+ * At what time did we generate our encryption key?
+ */
+ struct GNUNET_TIME_Absolute encrypt_key_created;
+
+ /**
+ * At what time did the other peer generate the decryption key?
+ */
+ struct GNUNET_TIME_Absolute decrypt_key_created;
+
+ /**
+ * When should the session time out (if there are no PONGs)?
+ */
+ struct GNUNET_TIME_Absolute timeout;
+
+ /**
+ * At what frequency are we currently re-trying SET_KEY messages?
+ */
+ struct GNUNET_TIME_Relative set_key_retry_frequency;
+
+ /**
+ * ID of task used for re-trying SET_KEY and PING message.
+ */
+ GNUNET_SCHEDULER_TaskIdentifier retry_set_key_task;
+
+ /**
+ * ID of task used for sending keep-alive pings.
+ */
+ GNUNET_SCHEDULER_TaskIdentifier keep_alive_task;
+
+ /**
+ * Bit map indicating which of the 32 sequence numbers before the last
+ * were received (good for accepting out-of-order packets and
+ * estimating reliability of the connection)
+ */
+ unsigned int last_packets_bitmap;
+
+ /**
+ * last sequence number received on this connection (highest)
+ */
+ uint32_t last_sequence_number_received;
+
+ /**
+ * last sequence number transmitted
+ */
+ uint32_t last_sequence_number_sent;
+
+ /**
+ * What was our PING challenge number (for this peer)?
+ */
+ uint32_t ping_challenge;
+
+ /**
+ * What is our connection status?
+ */
+ enum KxStateMachine status;
+
+};
+
+
/**
* Handle to peerinfo service.
*/
static struct GNUNET_PEERINFO_Handle *peerinfo;
+/**
+ * Our private key.
+ */
+static struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key;
+/**
+ * Our public key.
+ */
+static struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded my_public_key;
/**
- * We received a PING message. Validate and transmit
- * PONG.
- *
- * @param n sender of the PING
- * @param m the encrypted PING message itself
- * @param ats performance data
- * @param ats_count number of entries in ats (excluding 0-termination)
+ * Our message stream tokenizer (for encrypted payload).
*/
+static struct GNUNET_SERVER_MessageStreamTokenizer *mst;
+
+
+#if EXTRA_CHECKS
+/**
+ * Check internal invariants of the given KX record.
+ *
+ * @param kx record to check
+ * @param file filename for error reporting
+ * @param line line number for error reporting
+ */
static void
-handle_ping (struct Neighbour *n, const struct PingMessage *m,
- const struct GNUNET_TRANSPORT_ATS_Information *ats,
- uint32_t ats_count)
+check_kx_record (struct GSC_KeyExchangeInfo *kx,
+ const char *file,
+ int line)
{
- struct PingMessage t;
- struct PongMessage tx;
- struct PongMessage *tp;
- struct MessageEntry *me;
- struct GNUNET_CRYPTO_AesInitializationVector iv;
+ struct GNUNET_HashCode hc;
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Core service receives `%s' request from `%4s'.\n", "PING",
- GNUNET_i2s (&n->peer));
-#endif
- derive_iv (&iv, &n->decrypt_key, m->iv_seed, &my_identity);
- if (GNUNET_OK !=
- do_decrypt (n, &iv, &m->target, &t.target,
- sizeof (struct PingMessage) - ((void *) &m->target -
- (void *) m)))
+ if (NULL == kx->public_key)
return;
-#if DEBUG_HANDSHAKE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Decrypted `%s' to `%4s' with challenge %u decrypted using key %u, IV %u (salt %u)\n",
- "PING", GNUNET_i2s (&t.target), (unsigned int) t.challenge,
- (unsigned int) n->decrypt_key.crc32, GNUNET_CRYPTO_crc32_n (&iv,
- sizeof
- (iv)),
- m->iv_seed);
-#endif
- GNUNET_STATISTICS_update (stats, gettext_noop ("# PING messages decrypted"),
- 1, GNUNET_NO);
- if (0 !=
- memcmp (&t.target, &my_identity, sizeof (struct GNUNET_PeerIdentity)))
- {
- char sender[9];
- char peer[9];
+ GNUNET_CRYPTO_hash (kx->public_key, sizeof (*kx->public_key), &hc);
+ GNUNET_assert_at (0 == memcmp (&hc, &kx->peer, sizeof (struct GNUNET_HashCode)), file, line);
+}
- GNUNET_snprintf (sender, sizeof (sender), "%8s", GNUNET_i2s (&n->peer));
- GNUNET_snprintf (peer, sizeof (peer), "%8s", GNUNET_i2s (&t.target));
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _
- ("Received PING from `%s' for different identity: I am `%s', PONG identity: `%s'\n"),
- sender, GNUNET_i2s (&my_identity), peer);
- GNUNET_break_op (0);
- return;
- }
- update_neighbour_performance (n, ats, ats_count);
- me = GNUNET_malloc (sizeof (struct MessageEntry) +
- sizeof (struct PongMessage));
- GNUNET_CONTAINER_DLL_insert_after (n->encrypted_head, n->encrypted_tail,
- n->encrypted_tail, me);
- me->deadline = GNUNET_TIME_relative_to_absolute (MAX_PONG_DELAY);
- me->priority = PONG_PRIORITY;
- me->size = sizeof (struct PongMessage);
- tx.inbound_bw_limit = n->bw_in;
- tx.challenge = t.challenge;
- tx.target = t.target;
- tp = (struct PongMessage *) &me[1];
- tp->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_PONG);
- tp->header.size = htons (sizeof (struct PongMessage));
- tp->iv_seed =
- GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
- derive_pong_iv (&iv, &n->encrypt_key, tp->iv_seed, t.challenge, &n->peer);
- do_encrypt (n, &iv, &tx.challenge, &tp->challenge,
- sizeof (struct PongMessage) - ((void *) &tp->challenge -
- (void *) tp));
- GNUNET_STATISTICS_update (stats, gettext_noop ("# PONG messages created"), 1,
- GNUNET_NO);
-#if DEBUG_HANDSHAKE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Encrypting `%s' with challenge %u using key %u, IV %u (salt %u)\n",
- "PONG", (unsigned int) t.challenge,
- (unsigned int) n->encrypt_key.crc32, GNUNET_CRYPTO_crc32_n (&iv,
- sizeof
- (iv)),
- tp->iv_seed);
+
+/**
+ * Check internal invariants of the given KX record.
+ *
+ * @param kx record to check
+ */
+#define CHECK_KX(kx) check_kx_record(kx, __FILE__, __LINE__)
+#else
+#define CHECK_KX(kx)
#endif
- /* trigger queue processing */
- process_encrypted_neighbour_queue (n);
+
+/**
+ * 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,
+ const struct GNUNET_CRYPTO_AesSessionKey *skey, uint32_t seed,
+ struct GNUNET_TIME_Absolute creation_time)
+{
+ 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,
+ sizeof (ctx), NULL);
}
/**
- * We received a PONG message. Validate and update our status.
+ * Derive an IV from packet information
*
- * @param n sender of the PONG
- * @param m the encrypted PONG message itself
- * @param ats performance data
- * @param ats_count number of entries in ats (excluding 0-termination)
+ * @param iv initialization vector to initialize
+ * @param skey session key to use
+ * @param seed seed to use
+ * @param identity identity of the other peer to use
*/
static void
-handle_pong (struct Neighbour *n, const struct PongMessage *m,
- const struct GNUNET_TRANSPORT_ATS_Information *ats,
- uint32_t ats_count)
+derive_iv (struct GNUNET_CRYPTO_AesInitializationVector *iv,
+ const struct GNUNET_CRYPTO_AesSessionKey *skey, uint32_t seed,
+ const struct GNUNET_PeerIdentity *identity)
{
- struct PongMessage t;
- struct ConnectNotifyMessage *cnm;
- struct GNUNET_CRYPTO_AesInitializationVector iv;
- char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
- struct GNUNET_TRANSPORT_ATS_Information *mats;
- size_t size;
-
-#if DEBUG_HANDSHAKE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Core service receives `%s' response from `%4s'.\n", "PONG",
- GNUNET_i2s (&n->peer));
-#endif
- /* mark as garbage, just to be sure */
- memset (&t, 255, sizeof (t));
- derive_pong_iv (&iv, &n->decrypt_key, m->iv_seed, n->ping_challenge,
- &my_identity);
- if (GNUNET_OK !=
- do_decrypt (n, &iv, &m->challenge, &t.challenge,
- sizeof (struct PongMessage) - ((void *) &m->challenge -
- (void *) m)))
- {
- GNUNET_break_op (0);
- return;
- }
- GNUNET_STATISTICS_update (stats, gettext_noop ("# PONG messages decrypted"),
- 1, GNUNET_NO);
-#if DEBUG_HANDSHAKE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Decrypted `%s' from `%4s' with challenge %u using key %u, IV %u (salt %u)\n",
- "PONG", GNUNET_i2s (&t.target), (unsigned int) t.challenge,
- (unsigned int) n->decrypt_key.crc32, GNUNET_CRYPTO_crc32_n (&iv,
- sizeof
- (iv)),
- m->iv_seed);
-#endif
- if ((0 != memcmp (&t.target, &n->peer, sizeof (struct GNUNET_PeerIdentity)))
- || (n->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 (&n->peer),
- (unsigned int) n->ping_challenge);
- 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
- GNUNET_break_op (n->ping_challenge != t.challenge);
- return;
- }
- switch (n->status)
- {
- case PEER_STATE_DOWN:
- GNUNET_break (0); /* should be impossible */
- return;
- case PEER_STATE_KEY_SENT:
- GNUNET_break (0); /* should be impossible, how did we decrypt? */
- return;
- case PEER_STATE_KEY_RECEIVED:
- GNUNET_STATISTICS_update (stats,
- gettext_noop
- ("# Session keys confirmed via PONG"), 1,
- GNUNET_NO);
- n->status = PEER_STATE_KEY_CONFIRMED;
- {
- struct GNUNET_MessageHeader *hdr;
+ static const char ctx[] = "initialization vector";
- hdr = compute_type_map_message ();
- send_type_map_to_neighbour (hdr, &n->peer.hashPubKey, n);
- GNUNET_free (hdr);
- }
- if (n->bw_out_external_limit.value__ != t.inbound_bw_limit.value__)
- {
- n->bw_out_external_limit = t.inbound_bw_limit;
- n->bw_out =
- GNUNET_BANDWIDTH_value_min (n->bw_out_external_limit,
- n->bw_out_internal_limit);
- GNUNET_BANDWIDTH_tracker_update_quota (&n->available_send_window,
- n->bw_out);
- GNUNET_TRANSPORT_set_quota (transport, &n->peer, n->bw_in, n->bw_out);
- }
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Confirmed key via `%s' message for peer `%4s'\n", "PONG",
- GNUNET_i2s (&n->peer));
-#endif
- if (n->retry_set_key_task != GNUNET_SCHEDULER_NO_TASK)
- {
- GNUNET_SCHEDULER_cancel (n->retry_set_key_task);
- n->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
- }
- update_neighbour_performance (n, ats, ats_count);
- size =
- sizeof (struct ConnectNotifyMessage) +
- (n->ats_count) * sizeof (struct GNUNET_TRANSPORT_ATS_Information);
- if (size >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
- {
- GNUNET_break (0);
- /* recovery strategy: throw away performance data */
- GNUNET_array_grow (n->ats, n->ats_count, 0);
- size =
- sizeof (struct PeerStatusNotifyMessage) +
- n->ats_count * sizeof (struct GNUNET_TRANSPORT_ATS_Information);
- }
- cnm = (struct ConnectNotifyMessage *) buf;
- cnm->header.size = htons (size);
- cnm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_NOTIFY_CONNECT);
- cnm->ats_count = htonl (n->ats_count);
- cnm->peer = n->peer;
- mats = &cnm->ats;
- memcpy (mats, n->ats,
- n->ats_count * sizeof (struct GNUNET_TRANSPORT_ATS_Information));
- mats[n->ats_count].type = htonl (GNUNET_TRANSPORT_ATS_ARRAY_TERMINATOR);
- mats[n->ats_count].value = htonl (0);
- send_to_all_clients (&cnm->header, GNUNET_NO,
- GNUNET_CORE_OPTION_SEND_CONNECT);
- process_encrypted_neighbour_queue (n);
- /* fall-through! */
- case PEER_STATE_KEY_CONFIRMED:
- n->last_activity = GNUNET_TIME_absolute_get ();
- if (n->keep_alive_task != GNUNET_SCHEDULER_NO_TASK)
- GNUNET_SCHEDULER_cancel (n->keep_alive_task);
- n->keep_alive_task =
- GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_divide
- (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT,
- 2), &send_keep_alive, n);
- handle_peer_status_change (n);
- break;
- default:
- GNUNET_break (0);
- break;
- }
+ GNUNET_CRYPTO_aes_derive_iv (iv, skey, &seed, sizeof (seed),
+ &identity->hashPubKey.bits,
+ sizeof (identity->hashPubKey.bits), ctx,
+ sizeof (ctx), NULL);
}
/**
- * We received a SET_KEY message. Validate and update
- * our key material and status.
+ * Derive an IV from pong packet information
*
- * @param n the neighbour from which we received message m
- * @param m the set key message we received
- * @param ats performance data
- * @param ats_count number of entries in ats (excluding 0-termination)
+ * @param iv initialization vector to initialize
+ * @param skey session key to use
+ * @param seed seed to use
+ * @param challenge nonce to use
+ * @param identity identity of the other peer to use
*/
static void
-handle_set_key (struct Neighbour *n, const struct SetKeyMessage *m,
- const struct GNUNET_TRANSPORT_ATS_Information *ats,
- uint32_t ats_count)
+derive_pong_iv (struct GNUNET_CRYPTO_AesInitializationVector *iv,
+ const struct GNUNET_CRYPTO_AesSessionKey *skey, uint32_t seed,
+ uint32_t challenge, const struct GNUNET_PeerIdentity *identity)
{
- struct SetKeyMessage *m_cpy;
- struct GNUNET_TIME_Absolute t;
- struct GNUNET_CRYPTO_AesSessionKey k;
- struct PingMessage *ping;
- struct PongMessage *pong;
- enum PeerStateMachine sender_status;
+ static const char ctx[] = "pong initialization vector";
-#if DEBUG_CORE
+ GNUNET_CRYPTO_aes_derive_iv (iv, skey, &seed, sizeof (seed),
+ &identity->hashPubKey.bits,
+ sizeof (identity->hashPubKey.bits), &challenge,
+ sizeof (challenge), ctx, sizeof (ctx), NULL);
+}
+
+
+/**
+ * Encrypt size bytes from in and write the result to out. Use the
+ * key for outbound traffic of the given neighbour.
+ *
+ * @param kx key information context
+ * @param iv initialization vector to use
+ * @param in ciphertext
+ * @param out plaintext
+ * @param size size of in/out
+ * @return GNUNET_OK on success
+ */
+static int
+do_encrypt (struct GSC_KeyExchangeInfo *kx,
+ const struct GNUNET_CRYPTO_AesInitializationVector *iv,
+ const void *in, void *out, size_t size)
+{
+ if (size != (uint16_t) size)
+ {
+ GNUNET_break (0);
+ return GNUNET_NO;
+ }
+ GNUNET_assert (size ==
+ GNUNET_CRYPTO_aes_encrypt (in, (uint16_t) size,
+ &kx->encrypt_key, iv, out));
+ GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# bytes encrypted"), size,
+ GNUNET_NO);
+ /* 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,
- "Core service receives `%s' request from `%4s'.\n", "SET_KEY",
- GNUNET_i2s (&n->peer));
+ "Encrypted %u bytes for `%4s' using key %u, IV %u\n",
+ (unsigned int) size, GNUNET_i2s (&kx->peer),
+ (unsigned int) kx->encrypt_key.crc32, GNUNET_CRYPTO_crc32_n (iv,
+ sizeof
+ (iv)));
#endif
- if (n->public_key == NULL)
+ return GNUNET_OK;
+}
+
+
+/**
+ * Decrypt size bytes from in and write the result to out. Use the
+ * key for inbound traffic of the given neighbour. This function does
+ * NOT do any integrity-checks on the result.
+ *
+ * @param kx key information context
+ * @param iv initialization vector to use
+ * @param in ciphertext
+ * @param out plaintext
+ * @param size size of in/out
+ * @return GNUNET_OK on success
+ */
+static int
+do_decrypt (struct GSC_KeyExchangeInfo *kx,
+ const struct GNUNET_CRYPTO_AesInitializationVector *iv,
+ const void *in, void *out, size_t size)
+{
+ if (size != (uint16_t) size)
{
- if (n->pitr != NULL)
- {
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Ignoring `%s' message due to lack of public key for peer (still trying to obtain one).\n",
- "SET_KEY");
+ GNUNET_break (0);
+ return GNUNET_NO;
+ }
+ if ( (kx->status != KX_STATE_KEY_RECEIVED) && (kx->status != KX_STATE_UP) &&
+ (kx->status != KX_STATE_REKEY_SENT) &&
+ (kx->status != KX_STATE_REKEY) )
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (size !=
+ GNUNET_CRYPTO_aes_decrypt (in, (uint16_t) size, &kx->decrypt_key, iv,
+ out))
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+ GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# bytes decrypted"), size,
+ GNUNET_NO);
+ /* 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),
+ (unsigned int) kx->decrypt_key.crc32, GNUNET_CRYPTO_crc32_n (iv,
+ sizeof
+ (*iv)));
#endif
- return;
- }
-#if DEBUG_CORE
+ return GNUNET_OK;
+}
+
+
+/**
+ * Send our key (and encrypted PING) to the other peer.
+ *
+ * @param kx key exchange context
+ */
+static void
+send_key (struct GSC_KeyExchangeInfo *kx);
+
+
+/**
+ * Task that will retry "send_key" if our previous attempt failed.
+ *
+ * @param cls our 'struct GSC_KeyExchangeInfo'
+ * @param tc scheduler context
+ */
+static void
+set_key_retry_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ struct GSC_KeyExchangeInfo *kx = cls;
+
+ kx->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
+ kx->set_key_retry_frequency =
+ GNUNET_TIME_relative_multiply (kx->set_key_retry_frequency, 2);
+ send_key (kx);
+}
+
+
+/**
+ * PEERINFO is giving us a HELLO for a peer. Add the public key to
+ * the neighbour's struct and continue with the key exchange. Or, if
+ * we did not get a HELLO, just do nothing.
+ *
+ * @param cls the 'struct GSC_KeyExchangeInfo' to retry sending the key for
+ * @param peer the peer for which this is the HELLO
+ * @param hello HELLO message of that peer
+ * @param err_msg NULL if successful, otherwise contains error message
+ */
+static void
+process_hello (void *cls, const struct GNUNET_PeerIdentity *peer,
+ const struct GNUNET_HELLO_Message *hello, const char *err_msg)
+{
+ struct GSC_KeyExchangeInfo *kx = cls;
+ struct SetKeyMessage *skm;
+
+ CHECK_KX (kx);
+ if (NULL != err_msg)
+ {
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Lacking public key for peer, trying to obtain one (handle_set_key).\n");
-#endif
- m_cpy = GNUNET_malloc (sizeof (struct SetKeyMessage));
- memcpy (m_cpy, m, sizeof (struct SetKeyMessage));
- /* lookup n's public key, then try again */
- GNUNET_assert (n->skm == NULL);
- n->skm = m_cpy;
- n->pitr =
- GNUNET_PEERINFO_iterate (peerinfo, &n->peer, GNUNET_TIME_UNIT_MINUTES,
- &process_hello_retry_handle_set_key, n);
- GNUNET_STATISTICS_update (stats,
+ _("Error in communication with PEERINFO service\n"));
+ kx->pitr = NULL;
+ 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_add_delayed (kx->set_key_retry_frequency,
+ &set_key_retry_task, kx);
+ return;
+ }
+ if (NULL == peer)
+ {
+ kx->pitr = NULL;
+ if (NULL != kx->public_key)
+ return; /* done here */
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Failed to obtain public key for peer `%4s', delaying processing of SET_KEY\n",
+ GNUNET_i2s (&kx->peer));
+ GNUNET_STATISTICS_update (GSC_stats,
gettext_noop
- ("# SET_KEY messages deferred (need public key)"),
+ ("# Delayed connecting due to lack of public key"),
1, GNUNET_NO);
+ 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_add_delayed (kx->set_key_retry_frequency,
+ &set_key_retry_task, kx);
+ return;
+ }
+ GNUNET_break (0 == memcmp (peer, &kx->peer, sizeof (struct GNUNET_PeerIdentity)));
+ if (NULL != kx->public_key)
+ {
+ /* already have public key, why are we here? */
+ GNUNET_break (0);
+ return;
+ }
+ GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == kx->retry_set_key_task);
+ kx->public_key =
+ GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
+ if (GNUNET_OK != GNUNET_HELLO_get_key (hello, kx->public_key))
+ {
+ GNUNET_break (0);
+ GNUNET_free (kx->public_key);
+ kx->public_key = NULL;
+ CHECK_KX (kx);
+ return;
+ }
+ CHECK_KX (kx);
+ send_key (kx);
+ if (NULL != kx->skm_received)
+ {
+ skm = kx->skm_received;
+ kx->skm_received = NULL;
+ GSC_KX_handle_set_key (kx, &skm->header);
+ GNUNET_free (skm);
+ }
+}
+
+
+/**
+ * Start the key exchange with the given peer.
+ *
+ * @param pid identity of the peer to do a key exchange with
+ * @return key exchange information context
+ */
+struct GSC_KeyExchangeInfo *
+GSC_KX_start (const struct GNUNET_PeerIdentity *pid)
+{
+ struct GSC_KeyExchangeInfo *kx;
+
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Initiating key exchange with `%s'\n",
+ GNUNET_i2s (pid));
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop ("# key exchanges initiated"), 1,
+ GNUNET_NO);
+ kx = GNUNET_malloc (sizeof (struct GSC_KeyExchangeInfo));
+ kx->peer = *pid;
+ kx->set_key_retry_frequency = INITIAL_SET_KEY_RETRY_FREQUENCY;
+ kx->pitr =
+ GNUNET_PEERINFO_iterate (peerinfo, pid,
+ GNUNET_TIME_UNIT_FOREVER_REL /* timeout? */ ,
+ &process_hello, kx);
+ CHECK_KX (kx);
+ return kx;
+}
+
+
+/**
+ * Stop key exchange with the given peer. Clean up key material.
+ *
+ * @param kx key exchange to stop
+ */
+void
+GSC_KX_stop (struct GSC_KeyExchangeInfo *kx)
+{
+ GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# key exchanges stopped"),
+ 1, GNUNET_NO);
+ if (NULL != kx->pitr)
+ {
+ GNUNET_PEERINFO_iterate_cancel (kx->pitr);
+ kx->pitr = NULL;
+ }
+ if (kx->retry_set_key_task != GNUNET_SCHEDULER_NO_TASK)
+ {
+ GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
+ kx->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
+ }
+ if (kx->keep_alive_task != GNUNET_SCHEDULER_NO_TASK)
+ {
+ GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
+ kx->keep_alive_task = GNUNET_SCHEDULER_NO_TASK;
+ }
+ GNUNET_free_non_null (kx->skm_received);
+ GNUNET_free_non_null (kx->ping_received);
+ GNUNET_free_non_null (kx->pong_received);
+ GNUNET_free_non_null (kx->emsg_received);
+ GNUNET_free_non_null (kx->public_key);
+ GNUNET_free (kx);
+}
+
+
+/**
+ * We received a SET_KEY message. Validate and update
+ * our key material and status.
+ *
+ * @param kx key exchange status for the corresponding peer
+ * @param msg the set key message we received
+ */
+void
+GSC_KX_handle_set_key (struct GSC_KeyExchangeInfo *kx,
+ const struct GNUNET_MessageHeader *msg)
+{
+ const struct SetKeyMessage *m;
+ struct GNUNET_TIME_Absolute t;
+ struct GNUNET_CRYPTO_AesSessionKey k;
+ struct PingMessage *ping;
+ struct PongMessage *pong;
+ enum KxStateMachine sender_status;
+ uint16_t size;
+
+ CHECK_KX (kx);
+ size = ntohs (msg->size);
+ if (size != sizeof (struct SetKeyMessage))
+ {
+ GNUNET_break_op (0);
+ return;
+ }
+ m = (const struct SetKeyMessage *) msg;
+ GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# session keys received"),
+ 1, GNUNET_NO);
+
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Core service receives `%s' request from `%4s'.\n", "SET_KEY",
+ GNUNET_i2s (&kx->peer));
+ if (NULL == kx->public_key)
+ {
+ GNUNET_free_non_null (kx->skm_received);
+ kx->skm_received = (struct SetKeyMessage *) GNUNET_copy_message (msg);
return;
}
if (0 !=
- memcmp (&m->target, &my_identity, sizeof (struct GNUNET_PeerIdentity)))
+ memcmp (&m->target, &GSC_my_identity,
+ sizeof (struct GNUNET_PeerIdentity)))
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _
- ("Received `%s' message that was for `%s', not for me. Ignoring.\n"),
- "SET_KEY", GNUNET_i2s (&m->target));
+ _("`%s' is for `%s', not for me. Ignoring.\n"), "SET_KEY",
+ GNUNET_i2s (&m->target));
return;
}
if ((ntohl (m->purpose.size) !=
sizeof (struct GNUNET_PeerIdentity)) ||
(GNUNET_OK !=
GNUNET_CRYPTO_rsa_verify (GNUNET_SIGNATURE_PURPOSE_SET_KEY, &m->purpose,
- &m->signature, n->public_key)))
+ &m->signature, kx->public_key)))
{
/* invalid signature */
+ CHECK_KX (kx);
GNUNET_break_op (0);
return;
}
t = GNUNET_TIME_absolute_ntoh (m->creation_time);
- if (((n->status == PEER_STATE_KEY_RECEIVED) ||
- (n->status == PEER_STATE_KEY_CONFIRMED)) &&
- (t.abs_value < n->decrypt_key_created.abs_value))
+ if (((kx->status == KX_STATE_KEY_RECEIVED) || (kx->status == KX_STATE_UP)) &&
+ (t.abs_value < kx->decrypt_key_created.abs_value))
{
/* this could rarely happen due to massive re-ordering of
* messages on the network level, but is most likely either
GNUNET_break_op (0);
return;
}
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Decrypting key material.\n");
-#endif
if ((GNUNET_CRYPTO_rsa_decrypt
(my_private_key, &m->encrypted_key, &k,
sizeof (struct GNUNET_CRYPTO_AesSessionKey)) !=
(GNUNET_OK != GNUNET_CRYPTO_aes_check_session_key (&k)))
{
/* failed to decrypt !? */
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ "Invalid key %x decrypted by %s from message %u (origin: %s)\n",
+ (unsigned int) GNUNET_CRYPTO_crc32_n (&k, sizeof (struct GNUNET_CRYPTO_AesSessionKey)),
+ GNUNET_i2s (&GSC_my_identity),
+ (unsigned int) GNUNET_CRYPTO_crc32_n (&m->encrypted_key, sizeof (struct GNUNET_CRYPTO_RsaEncryptedData)),
+ GNUNET_h2s (&kx->peer.hashPubKey));
GNUNET_break_op (0);
return;
}
- GNUNET_STATISTICS_update (stats,
+ GNUNET_STATISTICS_update (GSC_stats,
gettext_noop ("# SET_KEY messages decrypted"), 1,
GNUNET_NO);
- n->decrypt_key = k;
- if (n->decrypt_key_created.abs_value != t.abs_value)
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received SET_KEY from `%s'\n",
+ GNUNET_i2s (&kx->peer));
+ kx->decrypt_key = k;
+ if (kx->decrypt_key_created.abs_value != t.abs_value)
{
/* fresh key, reset sequence numbers */
- n->last_sequence_number_received = 0;
- n->last_packets_bitmap = 0;
- n->decrypt_key_created = t;
+ kx->last_sequence_number_received = 0;
+ kx->last_packets_bitmap = 0;
+ kx->decrypt_key_created = t;
}
- update_neighbour_performance (n, ats, ats_count);
- sender_status = (enum PeerStateMachine) ntohl (m->sender_status);
- switch (n->status)
+ sender_status = (enum KxStateMachine) ntohl (m->sender_status);
+ switch (kx->status)
{
- case PEER_STATE_DOWN:
- n->status = PEER_STATE_KEY_RECEIVED;
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Responding to `%s' with my own key.\n", "SET_KEY");
-#endif
- send_key (n);
+ case KX_STATE_DOWN:
+ kx->status = KX_STATE_KEY_RECEIVED;
+ /* we're not up, so we are already doing 'send_key' */
break;
- case PEER_STATE_KEY_SENT:
- case PEER_STATE_KEY_RECEIVED:
- n->status = PEER_STATE_KEY_RECEIVED;
- if ((sender_status != PEER_STATE_KEY_RECEIVED) &&
- (sender_status != PEER_STATE_KEY_CONFIRMED))
- {
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Responding to `%s' with my own key (other peer has status %u).\n",
- "SET_KEY", (unsigned int) sender_status);
-#endif
- send_key (n);
- }
+ case KX_STATE_KEY_SENT:
+ kx->status = KX_STATE_KEY_RECEIVED;
+ /* we're not up, so we are already doing 'send_key' */
break;
- case PEER_STATE_KEY_CONFIRMED:
- if ((sender_status != PEER_STATE_KEY_RECEIVED) &&
- (sender_status != PEER_STATE_KEY_CONFIRMED))
- {
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Responding to `%s' with my own key (other peer has status %u), I was already fully up.\n",
- "SET_KEY", (unsigned int) sender_status);
-#endif
- send_key (n);
- }
+ case KX_STATE_KEY_RECEIVED:
+ /* we're not up, so we are already doing 'send_key' */
+ break;
+ 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! */
break;
default:
GNUNET_break (0);
break;
}
- if (n->pending_ping != NULL)
+ if (NULL != kx->ping_received)
{
- ping = n->pending_ping;
- n->pending_ping = NULL;
- handle_ping (n, ping, NULL, 0);
+ ping = kx->ping_received;
+ kx->ping_received = NULL;
+ GSC_KX_handle_ping (kx, &ping->header);
GNUNET_free (ping);
}
- if (n->pending_pong != NULL)
+ if (NULL != kx->pong_received)
{
- pong = n->pending_pong;
- n->pending_pong = NULL;
- handle_pong (n, pong, NULL, 0);
+ pong = kx->pong_received;
+ kx->pong_received = NULL;
+ GSC_KX_handle_pong (kx, &pong->header);
GNUNET_free (pong);
}
}
+/**
+ * We received a PING message. Validate and transmit
+ * a PONG message.
+ *
+ * @param kx key exchange status for the corresponding peer
+ * @param msg the encrypted PING message itself
+ */
+void
+GSC_KX_handle_ping (struct GSC_KeyExchangeInfo *kx,
+ const struct GNUNET_MessageHeader *msg)
+{
+ const struct PingMessage *m;
+ struct PingMessage t;
+ struct PongMessage tx;
+ struct PongMessage tp;
+ struct GNUNET_CRYPTO_AesInitializationVector iv;
+ uint16_t msize;
+
+ msize = ntohs (msg->size);
+ if (msize != sizeof (struct PingMessage))
+ {
+ GNUNET_break_op (0);
+ return;
+ }
+ 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) &&
+ (kx->status != KX_STATE_REKEY_SENT))
+ {
+ /* defer */
+ GNUNET_free_non_null (kx->ping_received);
+ kx->ping_received = (struct PingMessage *) GNUNET_copy_message (msg);
+ return;
+ }
+ m = (const struct PingMessage *) msg;
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Core service receives `%s' request from `%4s'.\n", "PING",
+ GNUNET_i2s (&kx->peer));
+ derive_iv (&iv, &kx->decrypt_key, m->iv_seed, &GSC_my_identity);
+ if (GNUNET_OK !=
+ do_decrypt (kx, &iv, &m->target, &t.target,
+ sizeof (struct PingMessage) - ((void *) &m->target -
+ (void *) m)))
+ {
+ GNUNET_break_op (0);
+ return;
+ }
+ if (0 !=
+ memcmp (&t.target, &GSC_my_identity, sizeof (struct GNUNET_PeerIdentity)))
+ {
+ char sender[9];
+ char peer[9];
+
+ GNUNET_snprintf (sender, sizeof (sender), "%8s", GNUNET_i2s (&kx->peer));
+ GNUNET_snprintf (peer, sizeof (peer), "%8s", GNUNET_i2s (&t.target));
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ _
+ ("Received PING from `%s' for different identity: I am `%s', PONG identity: `%s'\n"),
+ sender, GNUNET_i2s (&GSC_my_identity), peer);
+ GNUNET_break_op (0);
+ return;
+ }
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received PING from `%s'\n",
+ GNUNET_i2s (&kx->peer));
+ /* construct PONG */
+ tx.reserved = GNUNET_BANDWIDTH_VALUE_MAX;
+ tx.challenge = t.challenge;
+ tx.target = t.target;
+ tp.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_PONG);
+ tp.header.size = htons (sizeof (struct PongMessage));
+ tp.iv_seed =
+ GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
+ derive_pong_iv (&iv, &kx->encrypt_key, tp.iv_seed, t.challenge, &kx->peer);
+ do_encrypt (kx, &iv, &tx.challenge, &tp.challenge,
+ sizeof (struct PongMessage) - ((void *) &tp.challenge -
+ (void *) &tp));
+ GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# PONG messages created"),
+ 1, GNUNET_NO);
+ GSC_NEIGHBOURS_transmit (&kx->peer, &tp.header,
+ GNUNET_TIME_UNIT_FOREVER_REL /* FIXME: timeout */ );
+}
+
+
+/**
+ * Create a fresh SET KEY message for transmission to the other peer.
+ * Also creates a new key.
+ *
+ * @param kx key exchange context to create SET KEY message for
+ */
+static void
+setup_fresh_setkey (struct GSC_KeyExchangeInfo *kx)
+{
+ struct SetKeyMessage *skm;
+
+ GNUNET_CRYPTO_aes_create_session_key (&kx->encrypt_key);
+ kx->encrypt_key_created = GNUNET_TIME_absolute_get ();
+ skm = &kx->skm;
+ skm->header.size = htons (sizeof (struct SetKeyMessage));
+ skm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_SET_KEY);
+ skm->purpose.size =
+ htonl (sizeof (struct GNUNET_CRYPTO_RsaSignaturePurpose) +
+ sizeof (struct GNUNET_TIME_AbsoluteNBO) +
+ sizeof (struct GNUNET_CRYPTO_RsaEncryptedData) +
+ sizeof (struct GNUNET_PeerIdentity));
+ skm->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_SET_KEY);
+ skm->creation_time = GNUNET_TIME_absolute_hton (kx->encrypt_key_created);
+ skm->target = kx->peer;
+ CHECK_KX (kx);
+ GNUNET_assert (GNUNET_OK ==
+ GNUNET_CRYPTO_rsa_encrypt (&kx->encrypt_key,
+ sizeof (struct
+ GNUNET_CRYPTO_AesSessionKey),
+ kx->public_key,
+ &skm->encrypted_key));
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Encrypting key %x for %s resulting in message %u (origin: %s)\n",
+ (unsigned int) GNUNET_CRYPTO_crc32_n (&kx->encrypt_key, sizeof (struct GNUNET_CRYPTO_AesSessionKey)),
+ GNUNET_i2s (&kx->peer),
+ (unsigned int) GNUNET_CRYPTO_crc32_n (&skm->encrypted_key, sizeof (struct GNUNET_CRYPTO_RsaEncryptedData)),
+ GNUNET_h2s (&GSC_my_identity.hashPubKey));
+
+ GNUNET_assert (GNUNET_OK ==
+ GNUNET_CRYPTO_rsa_sign (my_private_key, &skm->purpose,
+ &skm->signature));
+}
+
+
+/**
+ * Create a fresh PING message for transmission to the other peer.
+ *
+ * @param kx key exchange context to create PING for
+ */
+static void
+setup_fresh_ping (struct GSC_KeyExchangeInfo *kx)
+{
+ struct PingMessage pp;
+ struct PingMessage *pm;
+ struct GNUNET_CRYPTO_AesInitializationVector iv;
+
+ pm = &kx->ping;
+ pm->header.size = htons (sizeof (struct PingMessage));
+ pm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_PING);
+ pm->iv_seed =
+ GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
+ derive_iv (&iv, &kx->encrypt_key, pm->iv_seed, &kx->peer);
+ pp.challenge = kx->ping_challenge;
+ pp.target = kx->peer;
+ do_encrypt (kx, &iv, &pp.target, &pm->target,
+ sizeof (struct PingMessage) - ((void *) &pm->target -
+ (void *) pm));
+}
+
+
+/**
+ * Task triggered when a neighbour entry is about to time out
+ * (and we should prevent this by sending a PING).
+ *
+ * @param cls the 'struct GSC_KeyExchangeInfo'
+ * @param tc scheduler context (not used)
+ */
+static void
+send_keep_alive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ struct GSC_KeyExchangeInfo *kx = cls;
+ struct GNUNET_TIME_Relative retry;
+ struct GNUNET_TIME_Relative left;
+
+ kx->keep_alive_task = GNUNET_SCHEDULER_NO_TASK;
+ left = GNUNET_TIME_absolute_get_remaining (kx->timeout);
+ if (0 == left.rel_value)
+ {
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop ("# sessions terminated by timeout"),
+ 1, GNUNET_NO);
+ GSC_SESSIONS_end (&kx->peer);
+ kx->status = KX_STATE_DOWN;
+ send_key (kx);
+ return;
+ }
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending KEEPALIVE to `%s'\n",
+ GNUNET_i2s (&kx->peer));
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop ("# keepalive messages sent"), 1,
+ GNUNET_NO);
+ setup_fresh_ping (kx);
+ GSC_NEIGHBOURS_transmit (&kx->peer, &kx->ping.header,
+ kx->set_key_retry_frequency);
+ retry =
+ GNUNET_TIME_relative_max (GNUNET_TIME_relative_divide (left, 2),
+ MIN_PING_FREQUENCY);
+ kx->keep_alive_task =
+ GNUNET_SCHEDULER_add_delayed (retry, &send_keep_alive, kx);
+}
+
+
+/**
+ * We've seen a valid message from the other peer.
+ * Update the time when the session would time out
+ * and delay sending our keep alive message further.
+ *
+ * @param kx key exchange where we saw activity
+ */
+static void
+update_timeout (struct GSC_KeyExchangeInfo *kx)
+{
+ kx->timeout =
+ GNUNET_TIME_relative_to_absolute
+ (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
+ if (kx->keep_alive_task != GNUNET_SCHEDULER_NO_TASK)
+ GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
+ kx->keep_alive_task =
+ GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_divide
+ (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT,
+ 2), &send_keep_alive, kx);
+}
+
+
+/**
+ * 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;
+
+ GNUNET_break (KX_STATE_UP == kx->status);
+ 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);
+}
+
/**
- * PEERINFO is giving us a HELLO for a peer. Add the public key to
- * the neighbour's struct and retry send_key. Or, if we did not get a
- * HELLO, just do nothing.
+ * We received a PONG message. Validate and update our status.
*
- * @param cls the 'struct Neighbour' to retry sending the key for
- * @param peer the peer for which this is the HELLO
- * @param hello HELLO message of that peer
- * @param err_msg NULL if successful, otherwise contains error message
+ * @param kx key exchange context for the the PONG
+ * @param msg the encrypted PONG message itself
*/
-static void
-process_hello_retry_send_key (void *cls, const struct GNUNET_PeerIdentity *peer,
- const struct GNUNET_HELLO_Message *hello,
- const char *err_msg)
+void
+GSC_KX_handle_pong (struct GSC_KeyExchangeInfo *kx,
+ const struct GNUNET_MessageHeader *msg)
{
- struct Neighbour *n = cls;
-
- if (err_msg != NULL)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Error in communication with PEERINFO service\n"));
- /* return; */
- }
+ const struct PongMessage *m;
+ struct PongMessage t;
+ struct EncryptedMessage *emsg;
+ struct GNUNET_CRYPTO_AesInitializationVector iv;
+ uint16_t msize;
- if (peer == NULL)
+ msize = ntohs (msg->size);
+ if (sizeof (struct PongMessage) != msize)
{
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Entered `%s' and `%s' is NULL!\n",
- "process_hello_retry_send_key", "peer");
-#endif
- n->pitr = NULL;
- if (n->public_key != NULL)
- {
- if (n->retry_set_key_task != GNUNET_SCHEDULER_NO_TASK)
- {
- GNUNET_SCHEDULER_cancel (n->retry_set_key_task);
- n->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
- }
- GNUNET_STATISTICS_update (stats,
- gettext_noop
- ("# SET_KEY messages deferred (need public key)"),
- -1, GNUNET_NO);
- send_key (n);
- }
- else
- {
-#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 (&n->peer));
-#endif
- GNUNET_STATISTICS_update (stats,
- gettext_noop
- ("# Delayed connecting due to lack of public key"),
- 1, GNUNET_NO);
- if (GNUNET_SCHEDULER_NO_TASK == n->retry_set_key_task)
- n->retry_set_key_task =
- GNUNET_SCHEDULER_add_delayed (n->set_key_retry_frequency,
- &set_key_retry_task, n);
- }
+ GNUNET_break_op (0);
return;
}
-
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Entered `%s' for peer `%4s'\n",
- "process_hello_retry_send_key", GNUNET_i2s (peer));
-#endif
- if (n->public_key != NULL)
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop ("# PONG messages received"), 1,
+ GNUNET_NO);
+ switch (kx->status)
{
- /* already have public key, why are we here? */
+ 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;
}
-
-#if DEBUG_CORE
+ m = (const struct PongMessage *) msg;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received new `%s' message for `%4s', initiating key exchange.\n",
- "HELLO", GNUNET_i2s (peer));
-#endif
- n->public_key =
- GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
- if (GNUNET_OK != GNUNET_HELLO_get_key (hello, n->public_key))
+ "Core service receives `%s' response from `%4s'.\n", "PONG",
+ GNUNET_i2s (&kx->peer));
+ /* 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,
+ &GSC_my_identity);
+ if (GNUNET_OK !=
+ do_decrypt (kx, &iv, &m->challenge, &t.challenge,
+ sizeof (struct PongMessage) - ((void *) &m->challenge -
+ (void *) m)))
{
- GNUNET_STATISTICS_update (stats,
- gettext_noop
- ("# Error extracting public key from HELLO"), 1,
- GNUNET_NO);
- GNUNET_free (n->public_key);
- n->public_key = NULL;
-#if DEBUG_CORE
+ GNUNET_break_op (0);
+ return;
+ }
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop ("# PONG messages decrypted"), 1,
+ GNUNET_NO);
+ if ((0 != memcmp (&t.target, &kx->peer, sizeof (struct GNUNET_PeerIdentity)))
+ || (kx->ping_challenge != t.challenge))
+ {
+ /* PONG malformed */
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "GNUNET_HELLO_get_key returned awfully\n");
-#endif
+ "Received malformed `%s' wanted sender `%4s' with challenge %u\n",
+ "PONG", GNUNET_i2s (&kx->peer),
+ (unsigned int) kx->ping_challenge);
+ 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);
+ return;
+ }
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received PONG from `%s'\n",
+ GNUNET_i2s (&kx->peer));
+ switch (kx->status)
+ {
+ case KX_STATE_DOWN:
+ GNUNET_break (0); /* should be impossible */
+ return;
+ case KX_STATE_KEY_SENT:
+ GNUNET_break (0); /* should be impossible */
return;
+ case KX_STATE_KEY_RECEIVED:
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop
+ ("# session keys confirmed via PONG"), 1,
+ GNUNET_NO);
+ kx->status = KX_STATE_UP;
+ GSC_SESSIONS_create (&kx->peer, kx);
+ CHECK_KX (kx);
+ schedule_rekey (kx);
+ GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == kx->keep_alive_task);
+ if (NULL != kx->emsg_received)
+ {
+ emsg = kx->emsg_received;
+ kx->emsg_received = NULL;
+ GSC_KX_handle_encrypted_message (kx, &emsg->header, NULL,
+ 0 /* FIXME: ATSI */ );
+ GNUNET_free (emsg);
+ }
+ update_timeout (kx);
+ break;
+ 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;
}
}
/**
* Send our key (and encrypted PING) to the other peer.
*
- * @param n the other peer
+ * @param kx key exchange context
*/
static void
-send_key (struct Neighbour *n)
+send_key (struct GSC_KeyExchangeInfo *kx)
{
- struct MessageEntry *pos;
- struct SetKeyMessage *sm;
- struct MessageEntry *me;
- struct PingMessage pp;
- struct PingMessage *pm;
- struct GNUNET_CRYPTO_AesInitializationVector iv;
-
- if (n->retry_set_key_task != GNUNET_SCHEDULER_NO_TASK)
+ CHECK_KX (kx);
+ if (GNUNET_SCHEDULER_NO_TASK != kx->retry_set_key_task)
{
- GNUNET_SCHEDULER_cancel (n->retry_set_key_task);
- n->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
+ GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
+ kx->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
}
- if (n->pitr != NULL)
+ if (KX_STATE_UP == kx->status)
+ return; /* nothing to do */
+ if (NULL == kx->public_key)
{
-#if DEBUG_CORE
+ /* lookup public key, then try again */
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Key exchange in progress with `%4s'.\n",
- GNUNET_i2s (&n->peer));
-#endif
- return; /* already in progress */
- }
- if (GNUNET_YES != n->is_connected)
- {
- GNUNET_STATISTICS_update (stats,
- gettext_noop
- ("# Asking transport to connect (for SET_KEY)"),
- 1, GNUNET_NO);
- GNUNET_TRANSPORT_try_connect (transport, &n->peer);
- return;
- }
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Asked to perform key exchange with `%4s'.\n",
- GNUNET_i2s (&n->peer));
-#endif
- if (n->public_key == NULL)
- {
- /* lookup n's public key, then try again */
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Lacking public key for `%4s', trying to obtain one (send_key).\n",
- GNUNET_i2s (&n->peer));
-#endif
- GNUNET_assert (n->pitr == NULL);
- n->pitr =
- GNUNET_PEERINFO_iterate (peerinfo, &n->peer,
- GNUNET_TIME_relative_multiply
- (GNUNET_TIME_UNIT_SECONDS, 20),
- &process_hello_retry_send_key, n);
+ "Trying to obtain public key for `%s'\n",
+ GNUNET_i2s (&kx->peer));
+ kx->pitr =
+ GNUNET_PEERINFO_iterate (peerinfo, &kx->peer,
+ GNUNET_TIME_UNIT_FOREVER_REL /* timeout? */ ,
+ &process_hello, kx);
return;
}
- pos = n->encrypted_head;
- while (pos != NULL)
- {
- if (GNUNET_YES == pos->is_setkey)
- {
- if (pos->sender_status == n->status)
- {
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s' message for `%4s' queued already\n", "SET_KEY",
- GNUNET_i2s (&n->peer));
-#endif
- goto trigger_processing;
- }
- GNUNET_CONTAINER_DLL_remove (n->encrypted_head, n->encrypted_tail, pos);
- GNUNET_free (pos);
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Removing queued `%s' message for `%4s', will create a new one\n",
- "SET_KEY", GNUNET_i2s (&n->peer));
-#endif
- break;
- }
- pos = pos->next;
- }
/* update status */
- switch (n->status)
+ switch (kx->status)
{
- case PEER_STATE_DOWN:
- n->status = PEER_STATE_KEY_SENT;
+ case KX_STATE_DOWN:
+ kx->status = KX_STATE_KEY_SENT;
+ /* setup 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);
break;
- case PEER_STATE_KEY_SENT:
+ case KX_STATE_KEY_SENT:
break;
- case PEER_STATE_KEY_RECEIVED:
+ case KX_STATE_KEY_RECEIVED:
+ break;
+ 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 PEER_STATE_KEY_CONFIRMED:
+ case KX_STATE_REKEY_SENT:
break;
default:
GNUNET_break (0);
- break;
+ return;
}
+ /* always update sender status in SET KEY message */
+ /* 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));
+ GSC_NEIGHBOURS_transmit (&kx->peer, &kx->skm.header,
+ kx->set_key_retry_frequency);
+ GSC_NEIGHBOURS_transmit (&kx->peer, &kx->ping.header,
+ kx->set_key_retry_frequency);
+ kx->retry_set_key_task =
+ GNUNET_SCHEDULER_add_delayed (kx->set_key_retry_frequency,
+ &set_key_retry_task, kx);
+}
- /* first, set key message */
- me = GNUNET_malloc (sizeof (struct MessageEntry) +
- sizeof (struct SetKeyMessage) +
- sizeof (struct PingMessage));
- me->deadline = GNUNET_TIME_relative_to_absolute (MAX_SET_KEY_DELAY);
- me->priority = SET_KEY_PRIORITY;
- me->size = sizeof (struct SetKeyMessage) + sizeof (struct PingMessage);
- me->is_setkey = GNUNET_YES;
- me->got_slack = GNUNET_YES; /* do not defer this one! */
- me->sender_status = n->status;
- GNUNET_CONTAINER_DLL_insert_after (n->encrypted_head, n->encrypted_tail,
- n->encrypted_tail, me);
- sm = (struct SetKeyMessage *) &me[1];
- sm->header.size = htons (sizeof (struct SetKeyMessage));
- sm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_SET_KEY);
- sm->sender_status =
- htonl ((int32_t)
- ((n->status ==
- PEER_STATE_DOWN) ? PEER_STATE_KEY_SENT : n->status));
- sm->purpose.size =
- htonl (sizeof (struct GNUNET_CRYPTO_RsaSignaturePurpose) +
- sizeof (struct GNUNET_TIME_AbsoluteNBO) +
- sizeof (struct GNUNET_CRYPTO_RsaEncryptedData) +
- sizeof (struct GNUNET_PeerIdentity));
- sm->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_SET_KEY);
- sm->creation_time = GNUNET_TIME_absolute_hton (n->encrypt_key_created);
- sm->target = n->peer;
- GNUNET_assert (GNUNET_OK ==
- GNUNET_CRYPTO_rsa_encrypt (&n->encrypt_key,
- sizeof (struct
- GNUNET_CRYPTO_AesSessionKey),
- n->public_key, &sm->encrypted_key));
+
+/**
+ * Encrypt and transmit a message with the given payload.
+ *
+ * @param kx key exchange context
+ * @param payload payload of the message
+ * @param payload_size number of bytes in 'payload'
+ */
+void
+GSC_KX_encrypt_and_transmit (struct GSC_KeyExchangeInfo *kx,
+ const void *payload, size_t payload_size)
+{
+ size_t used = payload_size + sizeof (struct EncryptedMessage);
+ char pbuf[used]; /* plaintext */
+ char cbuf[used]; /* ciphertext */
+ struct EncryptedMessage *em; /* encrypted message */
+ struct EncryptedMessage *ph; /* plaintext header */
+ struct GNUNET_CRYPTO_AesInitializationVector iv;
+ struct GNUNET_CRYPTO_AuthKey auth_key;
+
+ ph = (struct EncryptedMessage *) pbuf;
+ ph->iv_seed =
+ htonl (GNUNET_CRYPTO_random_u32
+ (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX));
+ ph->sequence_number = htonl (++kx->last_sequence_number_sent);
+ ph->reserved = GNUNET_BANDWIDTH_VALUE_MAX;
+ ph->timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
+ memcpy (&ph[1], payload, payload_size);
+
+ em = (struct EncryptedMessage *) cbuf;
+ em->header.size = htons (used);
+ em->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_ENCRYPTED_MESSAGE);
+ em->iv_seed = ph->iv_seed;
+ derive_iv (&iv, &kx->encrypt_key, ph->iv_seed, &kx->peer);
GNUNET_assert (GNUNET_OK ==
- GNUNET_CRYPTO_rsa_sign (my_private_key, &sm->purpose,
- &sm->signature));
- pm = (struct PingMessage *) &sm[1];
- pm->header.size = htons (sizeof (struct PingMessage));
- pm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_PING);
- pm->iv_seed =
- GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
- derive_iv (&iv, &n->encrypt_key, pm->iv_seed, &n->peer);
- pp.challenge = n->ping_challenge;
- pp.target = n->peer;
-#if DEBUG_HANDSHAKE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Encrypting `%s' and `%s' messages with challenge %u for `%4s' using key %u, IV %u (salt %u).\n",
- "SET_KEY", "PING", (unsigned int) n->ping_challenge,
- GNUNET_i2s (&n->peer), (unsigned int) n->encrypt_key.crc32,
- GNUNET_CRYPTO_crc32_n (&iv, sizeof (iv)), pm->iv_seed);
-#endif
- do_encrypt (n, &iv, &pp.target, &pm->target,
- sizeof (struct PingMessage) - ((void *) &pm->target -
- (void *) pm));
- GNUNET_STATISTICS_update (stats,
- gettext_noop
- ("# SET_KEY and PING messages created"), 1,
- GNUNET_NO);
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Have %llu ms left for `%s' transmission.\n",
- (unsigned long long)
- GNUNET_TIME_absolute_get_remaining (me->deadline).rel_value,
- "SET_KEY");
-#endif
-trigger_processing:
- /* trigger queue processing */
- process_encrypted_neighbour_queue (n);
- if ((n->status != PEER_STATE_KEY_CONFIRMED) &&
- (GNUNET_SCHEDULER_NO_TASK == n->retry_set_key_task))
- n->retry_set_key_task =
- GNUNET_SCHEDULER_add_delayed (n->set_key_retry_frequency,
- &set_key_retry_task, n);
+ do_encrypt (kx, &iv, &ph->sequence_number,
+ &em->sequence_number,
+ used - ENCRYPTED_HEADER_SIZE));
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Encrypted %u bytes for %s\n",
+ used - ENCRYPTED_HEADER_SIZE, GNUNET_i2s (&kx->peer));
+ derive_auth_key (&auth_key, &kx->encrypt_key, ph->iv_seed,
+ kx->encrypt_key_created);
+ GNUNET_CRYPTO_hmac (&auth_key, &em->sequence_number,
+ used - ENCRYPTED_HEADER_SIZE, &em->hmac);
+ GSC_NEIGHBOURS_transmit (&kx->peer, &em->header,
+ GNUNET_TIME_UNIT_FOREVER_REL);
}
/**
- * We received a SET_KEY message. Validate and update
- * our key material and status.
- *
- * @param n the neighbour from which we received message m
- * @param m the set key message we received
- * @param ats performance data
- * @param ats_count number of entries in ats (excluding 0-termination)
+ * Closure for 'deliver_message'
*/
-static void
-handle_set_key (struct Neighbour *n, const struct SetKeyMessage *m,
- const struct GNUNET_TRANSPORT_ATS_Information *ats,
- uint32_t ats_count);
+struct DeliverMessageContext
+{
+
+ /**
+ * Performance information for the connection.
+ */
+ const struct GNUNET_ATS_Information *atsi;
+
+ /**
+ * Sender of the message.
+ */
+ const struct GNUNET_PeerIdentity *peer;
+ /**
+ * Number of entries in 'atsi' array.
+ */
+ uint32_t atsi_count;
+};
/**
- * PEERINFO is giving us a HELLO for a peer. Add the public key to
- * the neighbour's struct and retry handling the set_key message. Or,
- * if we did not get a HELLO, just free the set key message.
+ * We received an encrypted message. Decrypt, validate and
+ * pass on to the appropriate clients.
*
- * @param cls pointer to the set key message
- * @param peer the peer for which this is the HELLO
- * @param hello HELLO message of that peer
- * @param err_msg NULL if successful, otherwise contains error message
+ * @param kx key exchange context for encrypting the message
+ * @param msg encrypted message
+ * @param atsi performance data
+ * @param atsi_count number of entries in ats (excluding 0-termination)
*/
-static void
-process_hello_retry_handle_set_key (void *cls,
- const struct GNUNET_PeerIdentity *peer,
- const struct GNUNET_HELLO_Message *hello,
- const char *err_msg)
+void
+GSC_KX_handle_encrypted_message (struct GSC_KeyExchangeInfo *kx,
+ const struct GNUNET_MessageHeader *msg,
+ const struct GNUNET_ATS_Information *atsi,
+ uint32_t atsi_count)
{
- struct Neighbour *n = cls;
- struct SetKeyMessage *sm = n->skm;
+ const struct EncryptedMessage *m;
+ struct EncryptedMessage *pt; /* plaintext */
+ struct GNUNET_HashCode ph;
+ uint32_t snum;
+ struct GNUNET_TIME_Absolute t;
+ struct GNUNET_CRYPTO_AesInitializationVector iv;
+ struct GNUNET_CRYPTO_AuthKey auth_key;
+ struct DeliverMessageContext dmc;
+ uint16_t size = ntohs (msg->size);
+ char buf[size] GNUNET_ALIGN;
- if (err_msg != NULL)
+ if (size <
+ sizeof (struct EncryptedMessage) + sizeof (struct GNUNET_MessageHeader))
{
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Error in communication with PEERINFO service\n"));
- /* return; */
+ GNUNET_break_op (0);
+ return;
}
-
- if (peer == NULL)
+ m = (const struct EncryptedMessage *) msg;
+ if ((kx->status != KX_STATE_KEY_RECEIVED) && (kx->status != KX_STATE_UP) &&
+ (kx->status != KX_STATE_REKEY_SENT) )
{
- n->skm = NULL;
- n->pitr = NULL;
- if (n->public_key != NULL)
- {
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received `%s' for `%4s', continuing processing of `%s' message.\n",
- "HELLO", GNUNET_i2s (&n->peer), "SET_KEY");
-#endif
- handle_set_key (n, sm, NULL, 0);
- }
- else
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _
- ("Ignoring `%s' message due to lack of public key for peer `%4s' (failed to obtain one).\n"),
- "SET_KEY", GNUNET_i2s (&n->peer));
- }
- GNUNET_free (sm);
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop
+ ("# failed to decrypt message (no session key)"),
+ 1, GNUNET_NO);
return;
}
- if (n->public_key != NULL)
- return; /* multiple HELLOs match!? */
- n->public_key =
- GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
- if (GNUNET_OK != GNUNET_HELLO_get_key (hello, n->public_key))
+ if (KX_STATE_KEY_RECEIVED == kx->status)
+ {
+ /* defer */
+ GNUNET_free_non_null (kx->emsg_received);
+ kx->emsg_received = (struct EncryptedMessage *) GNUNET_copy_message (msg);
+ return;
+ }
+ /* validate hash */
+ derive_auth_key (&auth_key, &kx->decrypt_key, m->iv_seed,
+ kx->decrypt_key_created);
+ GNUNET_CRYPTO_hmac (&auth_key, &m->sequence_number,
+ size - ENCRYPTED_HEADER_SIZE, &ph);
+ if (0 != memcmp (&ph, &m->hmac, sizeof (struct GNUNET_HashCode)))
{
+ /* checksum failed */
GNUNET_break_op (0);
- GNUNET_free (n->public_key);
- n->public_key = NULL;
+ return;
}
-}
-
-
+ derive_iv (&iv, &kx->decrypt_key, m->iv_seed, &GSC_my_identity);
+ /* decrypt */
+ if (GNUNET_OK !=
+ do_decrypt (kx, &iv, &m->sequence_number, &buf[ENCRYPTED_HEADER_SIZE],
+ size - ENCRYPTED_HEADER_SIZE))
+ return;
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Decrypted %u bytes from %s\n",
+ size - ENCRYPTED_HEADER_SIZE, GNUNET_i2s (&kx->peer));
+ pt = (struct EncryptedMessage *) buf;
-/**
- * Task that will retry "send_key" if our previous attempt failed
- * to yield a PONG.
- */
-static void
-set_key_retry_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
- struct Neighbour *n = cls;
+ /* validate sequence number */
+ snum = ntohl (pt->sequence_number);
+ if (kx->last_sequence_number_received == snum)
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "Received duplicate message, ignoring.\n");
+ /* duplicate, ignore */
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop ("# bytes dropped (duplicates)"),
+ size, GNUNET_NO);
+ return;
+ }
+ if ((kx->last_sequence_number_received > snum) &&
+ (kx->last_sequence_number_received - snum > 32))
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "Received ancient out of sequence message, ignoring.\n");
+ /* ancient out of sequence, ignore */
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop
+ ("# bytes dropped (out of sequence)"), size,
+ GNUNET_NO);
+ return;
+ }
+ if (kx->last_sequence_number_received > snum)
+ {
+ unsigned int rotbit = 1 << (kx->last_sequence_number_received - snum - 1);
-#if DEBUG_CORE
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Retrying key transmission to `%4s'\n",
- GNUNET_i2s (&n->peer));
-#endif
- n->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
- n->set_key_retry_frequency =
- GNUNET_TIME_relative_multiply (n->set_key_retry_frequency, 2);
- send_key (n);
-}
+ if ((kx->last_packets_bitmap & rotbit) != 0)
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "Received duplicate message, ignoring.\n");
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop ("# bytes dropped (duplicates)"),
+ size, GNUNET_NO);
+ /* duplicate, ignore */
+ return;
+ }
+ kx->last_packets_bitmap |= rotbit;
+ }
+ if (kx->last_sequence_number_received < snum)
+ {
+ unsigned int shift = (snum - kx->last_sequence_number_received);
+ if (shift >= 8 * sizeof (kx->last_packets_bitmap))
+ kx->last_packets_bitmap = 0;
+ else
+ kx->last_packets_bitmap <<= shift;
+ kx->last_sequence_number_received = snum;
+ }
-struct GSC_KeyExchangeInfo *
-GSC_KX_start (const struct GNUNET_PeerIdentity *pid)
-{
- struct GSC_KeyExchangeInfo *kx;
+ /* check timestamp */
+ t = GNUNET_TIME_absolute_ntoh (pt->timestamp);
+ if (GNUNET_TIME_absolute_get_duration (t).rel_value >
+ MAX_MESSAGE_AGE.rel_value)
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ _("Message received far too old (%llu ms). Content ignored.\n"),
+ GNUNET_TIME_absolute_get_duration (t).rel_value);
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop
+ ("# bytes dropped (ancient message)"), size,
+ GNUNET_NO);
+ return;
+ }
- kx = NULL;
- return kx;
+ /* process decrypted message(s) */
+ update_timeout (kx);
+ GNUNET_STATISTICS_update (GSC_stats,
+ gettext_noop ("# bytes of payload decrypted"),
+ size - sizeof (struct EncryptedMessage), GNUNET_NO);
+ dmc.atsi = atsi;
+ dmc.atsi_count = atsi_count;
+ dmc.peer = &kx->peer;
+ if (GNUNET_OK !=
+ GNUNET_SERVER_mst_receive (mst, &dmc,
+ &buf[sizeof (struct EncryptedMessage)],
+ size - sizeof (struct EncryptedMessage),
+ GNUNET_YES, GNUNET_NO))
+ GNUNET_break_op (0);
}
-void
-GSC_KX_stop (struct GSC_KeyExchangeInfo *kx)
+/**
+ * Deliver P2P message to interested clients.
+ * Invokes send twice, once for clients that want the full message, and once
+ * for clients that only want the header
+ *
+ * @param cls always NULL
+ * @param client who sent us the message (struct GSC_KeyExchangeInfo)
+ * @param m the message
+ */
+static int
+deliver_message (void *cls, void *client, const struct GNUNET_MessageHeader *m)
{
- if (kx->pitr != NULL)
+ struct DeliverMessageContext *dmc = client;
+
+ switch (ntohs (m->type))
{
- GNUNET_PEERINFO_iterate_cancel (kx->pitr);
- kx->pitr = NULL;
+ case GNUNET_MESSAGE_TYPE_CORE_BINARY_TYPE_MAP:
+ case GNUNET_MESSAGE_TYPE_CORE_COMPRESSED_TYPE_MAP:
+ GSC_SESSIONS_set_typemap (dmc->peer, m);
+ return GNUNET_OK;
+ default:
+ GSC_CLIENTS_deliver_message (dmc->peer, dmc->atsi, dmc->atsi_count, m,
+ ntohs (m->size),
+ GNUNET_CORE_OPTION_SEND_FULL_INBOUND);
+ GSC_CLIENTS_deliver_message (dmc->peer, dmc->atsi, dmc->atsi_count, m,
+ sizeof (struct GNUNET_MessageHeader),
+ GNUNET_CORE_OPTION_SEND_HDR_INBOUND);
}
- if (kx->retry_set_key_task != GNUNET_SCHEDULER_NO_TASK)
- GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
- GNUNET_free_non_null (kx->public_key);
- GNUNET_free (kx);
+ return GNUNET_OK;
}
-int
+/**
+ * Initialize KX subsystem.
+ *
+ * @return GNUNET_OK on success, GNUNET_SYSERR on failure
+ */
+int
GSC_KX_init ()
{
- peerinfo = GNUNET_PEERINFO_connect (cfg);
+ char *keyfile;
+
+ if (GNUNET_OK !=
+ GNUNET_CONFIGURATION_get_value_filename (GSC_cfg, "GNUNETD", "HOSTKEY",
+ &keyfile))
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ _
+ ("Core service is lacking HOSTKEY configuration setting. Exiting.\n"));
+ return GNUNET_SYSERR;
+ }
+ my_private_key = GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
+ GNUNET_free (keyfile);
+ if (NULL == my_private_key)
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ _("Core service could not access hostkey. Exiting.\n"));
+ return GNUNET_SYSERR;
+ }
+ GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &my_public_key);
+ GNUNET_CRYPTO_hash (&my_public_key, sizeof (my_public_key),
+ &GSC_my_identity.hashPubKey);
+ peerinfo = GNUNET_PEERINFO_connect (GSC_cfg);
if (NULL == peerinfo)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Could not access PEERINFO service. Exiting.\n"));
+ GNUNET_CRYPTO_rsa_key_free (my_private_key);
+ my_private_key = NULL;
return GNUNET_SYSERR;
}
+ mst = GNUNET_SERVER_mst_create (&deliver_message, NULL);
return GNUNET_OK;
}
-void
+/**
+ * Shutdown KX subsystem.
+ */
+void
GSC_KX_done ()
{
- if (peerinfo != NULL)
- {
- GNUNET_PEERINFO_disconnect (peerinfo);
- peerinfo = NULL;
- }
-
+ if (NULL != my_private_key)
+ {
+ GNUNET_CRYPTO_rsa_key_free (my_private_key);
+ my_private_key = NULL;
+ }
+ if (NULL != peerinfo)
+ {
+ GNUNET_PEERINFO_disconnect (peerinfo);
+ peerinfo = NULL;
+ }
+ if (NULL != mst)
+ {
+ GNUNET_SERVER_mst_destroy (mst);
+ mst = NULL;
+ }
}
+
+/* end of gnunet-service-core_kx.c */
projects / oweals / gnunet.git / blobdiff