initial commit

1 files changed, 1196 insertions, 0 deletions

diff --git a/code/core.c b/code/core.c
new file mode 100644
index 0000000..ced4c01
--- /dev/null
+++ b/code/core.c
@@ -0,0 +1,1196 @@
+#include "core.h"
+
+#include <string.h>
+
+int ecp_dhkey_generate(ECPContext *ctx, ECPDHKey *key) {
+    int rv;
+    
+    if (ctx->rng == NULL) return ECP_ERR_RNG;
+
+    rv = ctx->cr.dh_mkpair(&key->public, &key->private, ctx->rng);
+    if (rv) return rv;
+
+    key->valid = 1;
+    return ECP_OK;
+}
+
+int ecp_node_init(ECPContext *ctx, ECPNode *node, void *addr, ecp_dh_public_t *public) {
+    int rv = ctx->tr.addr_set(&node->addr, addr);
+    if (rv) return ECP_ERR_NET_ADDR;
+
+    memcpy(&node->public, public, sizeof(node->public));
+    return ECP_OK;
+}
+
+ssize_t ecp_pack(ECPContext *ctx, unsigned char *packet, size_t pkt_size, unsigned char s_idx, unsigned char c_idx, ecp_dh_public_t *public, ecp_aead_key_t *shsec, unsigned char *nonce, unsigned char *seq, unsigned char *payload, size_t payload_size) {
+    ssize_t rv;
+
+    if (packet == NULL) return ECP_ERR;
+    if (payload == NULL) return ECP_ERR;
+
+    packet[0] = 0;
+    packet[1] = 0;
+    s_idx = s_idx & 0x0F;
+    c_idx = c_idx & 0x0F;
+    packet[ECP_SIZE_PROTO] = (s_idx << 4) | c_idx;
+    ctx->cr.dh_pub_to_buf(packet+ECP_SIZE_PROTO+1, public);
+    memcpy(packet+ECP_SIZE_PROTO+1+ECP_ECDH_SIZE_KEY, nonce, ECP_AEAD_SIZE_NONCE);
+
+    memcpy(payload, seq, ECP_SIZE_SEQ);
+    rv = ctx->cr.aead_enc(packet+ECP_SIZE_PKT_HDR, pkt_size-ECP_SIZE_PKT_HDR, payload, payload_size, shsec, packet+ECP_SIZE_PROTO+1+ECP_ECDH_SIZE_KEY);
+    if (rv < 0) return ECP_ERR_ENCRYPT;
+    
+    memcpy(nonce, packet+ECP_SIZE_PKT_HDR, ECP_AEAD_SIZE_NONCE);
+        
+    return rv+ECP_SIZE_PKT_HDR;
+}
+    
+int ecp_ctx_create(ECPContext *ctx) {
+    int rv;
+    
+    if (ctx == NULL) return ECP_ERR;
+
+    memset(ctx, 0, sizeof(ECPContext));
+
+    rv = ecp_crypto_init(&ctx->cr);
+    if (rv) return rv;
+#ifdef ECP_WITH_HTABLE
+    rv = ecp_htable_init(&ctx->ht);
+    if (rv) return rv;
+#endif
+    rv = ecp_transport_init(&ctx->tr);
+    if (rv) return rv;
+    rv = ecp_time_init(&ctx->tm);
+    if (rv) return rv;
+    
+    return ECP_OK;
+}
+
+int ecp_ctx_destroy(ECPContext *ctx) {
+    return ECP_OK;
+}
+
+static int ctable_create(ECPSockCTable *conn, ECPContext *ctx) {
+    int rv = ECP_OK;
+    
+    memset(conn, 0, sizeof(ECPSockCTable));
+    if (ctx->ht.init) {
+        conn->htable = ctx->ht.create(ctx);
+        if (conn->htable == NULL) return ECP_ERR_ALLOC;
+    }
+
+#ifdef ECP_WITH_PTHREAD
+    rv = pthread_mutex_init(&conn->mutex, NULL);
+    if (rv && ctx->ht.init) ctx->ht.destroy(conn->htable);
+#endif
+    return rv;
+}
+
+static void ctable_destroy(ECPSockCTable *conn, ECPContext *ctx) {
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_destroy(&conn->mutex);
+#endif
+    if (ctx->ht.init) ctx->ht.destroy(conn->htable);
+}
+
+static int ctable_insert(ECPConnection *conn) {
+    ECPSocket *sock = conn->sock;
+    ECPContext *ctx = sock->ctx;
+
+    if (ctx->ht.init) {
+        int i, rv = ECP_OK;
+        if (conn->out) {
+            for (i=0; i<ECP_MAX_CONN_KEY; i++) {
+                if (conn->key[i].valid) rv = ctx->ht.insert(sock->conn.htable, ctx->cr.dh_pub_get_buf(&conn->key[i].public), conn);
+                if (rv) {
+                    int j;
+                    for (j=0; j<i; j++) if (conn->key[j].valid) ctx->ht.remove(sock->conn.htable, ctx->cr.dh_pub_get_buf(&conn->key[j].public));
+                    return rv;
+                }
+            }
+        } else {
+            ECPDHRKeyBucket *remote = &conn->remote;
+
+            for (i=0; i<ECP_MAX_NODE_KEY; i++) {
+                if (remote->key[i].idx != ECP_ECDH_IDX_INV) rv = ctx->ht.insert(sock->conn.htable, ctx->cr.dh_pub_get_buf(&remote->key[i].public), conn);
+                if (rv) {
+                    int j;
+                    for (j=0; j<i; j++) if (remote->key[j].idx != ECP_ECDH_IDX_INV) ctx->ht.remove(sock->conn.htable, ctx->cr.dh_pub_get_buf(&remote->key[j].public));
+                    return rv;
+                }
+            }
+        }
+    } else {
+        if (sock->conn.size == ECP_MAX_SOCK_CONN) return ECP_ERR_MAX_SOCK_CONN;
+        sock->conn.array[sock->conn.size] = conn;
+        sock->conn.size++;
+    }
+
+    return ECP_OK;
+}
+
+static void ctable_remove(ECPConnection *conn) {
+    int i;
+    ECPSocket *sock = conn->sock;
+    ECPContext *ctx = sock->ctx;
+    
+    if (ctx->ht.init) {
+        int i;
+        if (conn->out) {
+            for (i=0; i<ECP_MAX_CONN_KEY; i++) if (conn->key[i].valid) ctx->ht.remove(sock->conn.htable, ctx->cr.dh_pub_get_buf(&conn->key[i].public));
+        } else {
+            ECPDHRKeyBucket *remote = &conn->remote;
+            for (i=0; i<ECP_MAX_NODE_KEY; i++) if (remote->key[i].idx != ECP_ECDH_IDX_INV) ctx->ht.remove(sock->conn.htable, ctx->cr.dh_pub_get_buf(&remote->key[i].public));
+        }
+    } else {
+        for (i=0; i<sock->conn.size; i++) {
+            if (conn == sock->conn.array[i]) {
+                sock->conn.array[i] = sock->conn.array[sock->conn.size-1];
+                sock->conn.array[sock->conn.size-1] = NULL;
+                sock->conn.size--;
+                return;
+            }
+        }
+    }
+}
+
+static ECPConnection *ctable_search(ECPSocket *sock, unsigned char c_idx, unsigned char *c_public, ECPNetAddr *addr) {
+    ECPConnection *conn = NULL;
+    int i;
+    
+    if (sock->ctx->ht.init) {
+        return sock->ctx->ht.search(sock->conn.htable, c_public);
+    } else {
+        if (c_public) {
+            for (i=0; i<sock->conn.size; i++) {
+                conn = sock->conn.array[i];
+                if (conn->out) {
+                    if ((c_idx < ECP_MAX_CONN_KEY) && conn->key[c_idx].valid && sock->ctx->cr.dh_pub_eq(c_public, &conn->key[c_idx].public))
+                        return conn;
+                } else {
+                    if ((c_idx < ECP_MAX_SOCK_KEY) && (conn->remote.key_idx_map[c_idx] != ECP_ECDH_IDX_INV) && sock->ctx->cr.dh_pub_eq(c_public, &conn->remote.key[conn->remote.key_idx_map[c_idx]].public))
+                        return conn;
+                }
+            }
+        } else if (addr) {
+            /* in case server is not returning client's public key in packet */
+            for (i=0; i<sock->conn.size; i++) {
+                conn = sock->conn.array[i];
+                if (conn->out && conn->sock->ctx->tr.addr_eq(&conn->node.addr, addr)) return conn;
+            }
+        }
+    }
+
+    return NULL;
+}
+
+static ssize_t conn_handle_open(ECPConnection *conn, unsigned char ptype, unsigned char *payload, ssize_t size);
+static ssize_t conn_handle_kget(ECPConnection *conn, unsigned char ptype, unsigned char *payload, ssize_t size);
+static ssize_t conn_handle_kput(ECPConnection *conn, unsigned char ptype, unsigned char *payload, ssize_t size);
+
+int ecp_sock_create(ECPSocket *sock, ECPContext *ctx, ECPDHKey *key) {
+    int rv = ECP_OK; 
+    
+    if (sock == NULL) return ECP_ERR;
+    if (ctx == NULL) return ECP_ERR;
+    if (key == NULL) return ECP_ERR;
+
+    memset(sock, 0, sizeof(ECPSocket));
+    sock->ctx = ctx;
+    sock->poll_timeout = ECP_POLL_TIMEOUT;
+    sock->key_curr = 0;
+    sock->key_perma = *key;
+    sock->handler[ECP_PTYPE_OPEN] = conn_handle_open;
+    sock->handler[ECP_PTYPE_KGET] = conn_handle_kget;
+    sock->handler[ECP_PTYPE_KPUT] = conn_handle_kput;
+
+    rv = ecp_dhkey_generate(sock->ctx, &sock->key[sock->key_curr]);
+    if (!rv) rv = ctable_create(&sock->conn, sock->ctx);
+    
+    if (rv) return rv;
+    
+    rv = ecp_timer_create(&sock->timer);
+    if (rv) {
+        ctable_destroy(&sock->conn, sock->ctx);
+    }
+    
+#ifdef ECP_WITH_PTHREAD
+    if (!rv) rv = pthread_mutex_init(&sock->mutex, NULL);
+    if (rv) {
+        ecp_timer_destroy(&sock->timer);
+        ctable_destroy(&sock->conn, sock->ctx);
+    }
+#endif
+
+    return rv;
+}
+
+void ecp_sock_destroy(ECPSocket *sock) {
+    ecp_timer_destroy(&sock->timer);
+    ctable_destroy(&sock->conn, sock->ctx);
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_destroy(&sock->mutex);
+#endif
+}
+
+int ecp_sock_open(ECPSocket *sock, void *myaddr) {
+    return sock->ctx->tr.open(&sock->sock, myaddr);
+}
+
+void ecp_sock_close(ECPSocket *sock) {
+    sock->ctx->tr.close(&sock->sock);
+}
+
+int ecp_sock_dhkey_get_curr(ECPSocket *sock, unsigned char *idx, unsigned char *public) {
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&sock->mutex);
+#endif
+
+    *idx = sock->key_curr;
+    if (*idx != ECP_ECDH_IDX_INV) sock->ctx->cr.dh_pub_to_buf(public, &sock->key[sock->key_curr].public);
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&sock->mutex);
+#endif
+
+    if (*idx == ECP_ECDH_IDX_INV) return ECP_ERR_ECDH_IDX;
+    return ECP_OK;
+}
+
+int ecp_sock_dhkey_new(ECPSocket *sock) {
+    ECPDHKey new_key;
+    int rv = ecp_dhkey_generate(sock->ctx, &new_key);
+    if (rv) return rv;
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&sock->mutex);
+#endif
+    sock->key_curr = (sock->key_curr + 1) % ECP_MAX_SOCK_KEY;
+    sock->key[sock->key_curr] = new_key;
+    sock->key[(sock->key_curr + 1) % ECP_MAX_SOCK_KEY].valid = 0;
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&sock->mutex);
+#endif
+
+    return ECP_OK;
+}
+
+static ECPDHKey *conn_dhkey_get(ECPConnection *conn, unsigned char idx) {
+    if (conn->key_curr == ECP_ECDH_IDX_INV) {
+        if (idx < ECP_MAX_SOCK_KEY) return &conn->sock->key[idx];
+    } else {
+        if (idx < ECP_MAX_CONN_KEY) return &conn->key[idx];
+    }
+    return NULL;
+}
+
+static int conn_dhkey_new_pair(ECPConnection *conn, ECPDHKey *key) {
+    /* called when client makes new key pair */
+    ECPSocket *sock = conn->sock;
+    ECPContext *ctx = sock->ctx;
+
+    conn->key_curr = conn->key_curr == ECP_ECDH_IDX_INV ? 0 : (conn->key_curr+1) % ECP_MAX_CONN_KEY;
+    if (ctx->ht.init && conn->out && ecp_conn_is_reg(conn)) {
+        int rv;
+        unsigned char *pub_s = NULL;
+        if ((conn->key_curr != ECP_ECDH_IDX_INV) && conn->key[conn->key_curr].valid) {
+            pub_s = ctx->cr.dh_pub_get_buf(&conn->key[conn->key_curr].public);
+            ctx->ht.remove(sock->conn.htable, pub_s);
+        }
+        pub_s = ctx->cr.dh_pub_get_buf(&key->public);
+        rv = ctx->ht.insert(sock->conn.htable, pub_s, conn);
+        if (rv) return rv;
+    }
+    conn->key[conn->key_curr] = *key;
+    conn->key_idx_map[conn->key_curr] = ECP_ECDH_IDX_INV;
+
+    return ECP_OK;
+}
+
+static int conn_dhkey_new_pub_local(ECPConnection *conn, unsigned char idx) {
+    // Remote obtained our key
+    unsigned char new = conn->key_idx_curr == ECP_ECDH_IDX_INV ? 0 : (conn->key_idx_curr+1) % ECP_MAX_NODE_KEY;
+    int i;
+    
+    if (idx >= ECP_MAX_SOCK_KEY) return ECP_ERR_ECDH_IDX;
+
+    if (conn->key_idx[new] != ECP_ECDH_IDX_INV) conn->key_idx_map[conn->key_idx[new]] = ECP_ECDH_IDX_INV;
+    conn->key_idx_map[idx] = new;
+    conn->key_idx[new] = idx;
+    conn->key_idx_curr = new;
+
+    for (i=0; i<ECP_MAX_NODE_KEY; i++) {
+        conn->shared[new][i].valid = 0;
+    }
+    return ECP_OK;
+}
+
+
+static int conn_dhkey_new_pub_remote(ECPConnection *conn, unsigned char idx, unsigned char *public) {
+    // We obtained remote key
+    ECPSocket *sock = conn->sock;
+    ECPContext *ctx = sock->ctx;
+    ECPDHRKeyBucket *remote = &conn->remote;
+    unsigned char new = remote->key_curr == ECP_ECDH_IDX_INV ? 0 : (remote->key_curr+1) % ECP_MAX_NODE_KEY;
+    int i;
+
+    if (idx >= ECP_MAX_SOCK_KEY) return ECP_ERR_ECDH_IDX;
+    if ((remote->key_idx_map[idx] != ECP_ECDH_IDX_INV) && ctx->cr.dh_pub_eq(public, &remote->key[remote->key_idx_map[idx]].public)) return ECP_ERR_ECDH_KEY_DUP;
+
+    if (ctx->ht.init && !conn->out && ecp_conn_is_reg(conn)) {
+        if (remote->key[new].idx != ECP_ECDH_IDX_INV) {
+            unsigned char *pub_s = ctx->cr.dh_pub_get_buf(&remote->key[new].public);
+            ctx->ht.remove(sock->conn.htable, pub_s);
+        }
+        int rv = ctx->ht.insert(sock->conn.htable, public, conn);
+        if (rv) return rv;
+    }
+    
+    if (remote->key[new].idx != ECP_ECDH_IDX_INV) remote->key_idx_map[remote->key[new].idx] = ECP_ECDH_IDX_INV;
+    remote->key_idx_map[idx] = new;
+    ctx->cr.dh_pub_from_buf(&remote->key[new].public, public);
+    remote->key[new].idx = idx;
+    remote->key_curr = new;
+
+    for (i=0; i<ECP_MAX_NODE_KEY; i++) {
+        conn->shared[i][new].valid = 0;
+    }
+    return ECP_OK;
+}
+
+static int conn_shsec_get(ECPConnection *conn, unsigned char s_idx, unsigned char c_idx, ecp_aead_key_t *shsec) {
+    if (s_idx == ECP_ECDH_IDX_PERMA) {
+        ECPDHKey *priv = NULL;
+        ecp_dh_public_t *public_p = NULL;
+        
+        if (conn->out) {
+            public_p = &conn->node.public;
+            priv = conn_dhkey_get(conn, c_idx);
+        } else {
+            ECPDHRKey *pub = NULL;
+            
+            if (c_idx >= ECP_MAX_SOCK_KEY) return ECP_ERR_ECDH_IDX;
+            if (conn->remote.key_idx_map[c_idx] == ECP_ECDH_IDX_INV) return ECP_ERR_ECDH_IDX_REMOTE;
+
+            pub = &conn->remote.key[conn->remote.key_idx_map[c_idx]];
+            public_p = pub->idx != ECP_ECDH_IDX_INV ? &pub->public : NULL;
+            priv = &conn->sock->key_perma;
+        }
+        if (public_p == NULL) return ECP_ERR_ECDH_IDX;
+        if ((priv == NULL) || !priv->valid) return ECP_ERR_ECDH_IDX;
+        conn->sock->ctx->cr.dh_shsec(shsec, public_p, &priv->private);
+    } else {
+        unsigned char l_idx = conn->out ? c_idx : s_idx;
+        unsigned char r_idx = conn->out ? s_idx : c_idx;
+        ECPDHShared *shared = NULL;
+
+        if ((l_idx >= ECP_MAX_SOCK_KEY) || (r_idx >= ECP_MAX_SOCK_KEY)) return ECP_ERR_ECDH_IDX;
+
+        if (conn->key_idx_map[l_idx] == ECP_ECDH_IDX_INV) return ECP_ERR_ECDH_IDX_LOCAL;
+        if (conn->remote.key_idx_map[r_idx] == ECP_ECDH_IDX_INV) return ECP_ERR_ECDH_IDX_REMOTE;
+
+        shared = &conn->shared[conn->key_idx_map[l_idx]][conn->remote.key_idx_map[r_idx]];
+
+        if (!shared->valid) {
+            ECPDHRKeyBucket *remote = &conn->remote;
+            ECPDHRKey *pub = &remote->key[conn->remote.key_idx_map[r_idx]];
+            ECPDHKey *priv = conn_dhkey_get(conn, l_idx);
+
+            if ((pub == NULL) || (pub->idx == ECP_ECDH_IDX_INV)) return ECP_ERR_ECDH_IDX;
+            if ((priv == NULL) || !priv->valid) return ECP_ERR_ECDH_IDX;
+            conn->sock->ctx->cr.dh_shsec(&shared->secret, &pub->public, &priv->private);
+            shared->valid = 1;
+        }
+
+        memcpy(shsec, &shared->secret, sizeof(shared->secret));
+    }
+    
+    return ECP_OK;
+}
+
+static int conn_shsec_set(ECPConnection *conn, unsigned char s_idx, unsigned char c_idx, ecp_aead_key_t *shsec) {
+    unsigned char l_idx = conn->out ? c_idx : s_idx;
+    unsigned char r_idx = conn->out ? s_idx : c_idx;
+    ECPDHShared *shared = NULL;
+    
+    if ((l_idx >= ECP_MAX_SOCK_KEY) || (r_idx >= ECP_MAX_SOCK_KEY)) return ECP_ERR_ECDH_IDX;
+
+    if (conn->key_idx_map[l_idx] == ECP_ECDH_IDX_INV) return ECP_ERR_ECDH_IDX_LOCAL;
+    if (conn->remote.key_idx_map[r_idx] == ECP_ECDH_IDX_INV) return ECP_ERR_ECDH_IDX_REMOTE;
+
+    shared = &conn->shared[conn->key_idx_map[l_idx]][conn->remote.key_idx_map[r_idx]];
+    memcpy(&shared->secret, shsec, sizeof(shared->secret));
+    shared->valid = 1;
+    
+    return ECP_OK;
+}
+
+
+static int conn_new(ECPConnection **_conn, ECPSocket *sock, unsigned char s_idx, unsigned char c_idx, unsigned char *c_public, ecp_aead_key_t *shsec, unsigned char *payload, size_t payload_size) {
+    ECPConnection *conn = NULL;
+    int rv = ECP_OK;
+    
+    if (_conn == NULL) return ECP_ERR;
+    if (sock == NULL) return ECP_ERR;
+
+    conn = sock->ctx->conn_alloc ? sock->ctx->conn_alloc() : NULL;
+    if (conn == NULL) return ECP_ERR_ALLOC;
+
+    rv = ecp_conn_create(conn, sock);
+    if (rv) {
+        if (sock->ctx->conn_free) sock->ctx->conn_free(conn);
+        return rv;
+    }
+    conn->refcount = 1;
+    rv = conn_dhkey_new_pub_local(conn, s_idx);
+    if (!rv) rv = conn_dhkey_new_pub_remote(conn, c_idx, c_public);
+    if (!rv) rv = conn_shsec_set(conn, s_idx, c_idx, shsec);
+    if (!rv && sock->conn_create) rv = sock->conn_create(conn, payload, payload_size);
+    if (rv) {
+        ecp_conn_destroy(conn);
+        if (sock->ctx->conn_free) sock->ctx->conn_free(conn);
+        return rv;
+    }
+
+    rv = ecp_conn_register(conn);
+    if (rv) {
+        if (sock->conn_destroy) sock->conn_destroy(conn);
+        ecp_conn_destroy(conn);
+        if (sock->ctx->conn_free) sock->ctx->conn_free(conn);
+        return rv;
+    }
+
+    *_conn = conn;
+    return rv;
+}
+
+static ssize_t conn_handle_open(ECPConnection *conn, unsigned char ptype, unsigned char *payload, ssize_t size) {
+    ecp_conn_handler_t *handler = conn->handler ? conn->handler->f[ptype] : NULL;
+
+    if (conn->out) {
+        if (size < 0) return handler ? handler(conn, ptype, payload, size) : 0;
+
+#ifdef ECP_WITH_PTHREAD
+        pthread_mutex_lock(&conn->mutex);
+#endif
+        if (!ecp_conn_is_open(conn)) conn->flags |= ECP_CONN_FLAG_OPEN;
+#ifdef ECP_WITH_PTHREAD
+        pthread_mutex_unlock(&conn->mutex);
+#endif
+
+        return handler ? handler(conn, ptype, payload, size) : 0;
+    } else {
+        if (size < 0) return ECP_ERR;
+
+#ifdef ECP_WITH_PTHREAD
+        pthread_mutex_lock(&conn->mutex);
+#endif
+        if (!ecp_conn_is_open(conn)) conn->flags |= ECP_CONN_FLAG_OPEN;
+#ifdef ECP_WITH_PTHREAD
+        pthread_mutex_unlock(&conn->mutex);
+#endif
+
+        ssize_t _rv = ecp_send(conn, ECP_PTYPE_OPEN, NULL, 0);
+
+        return handler ? handler(conn, ptype, payload, size) : 0;
+    }
+
+    return ECP_ERR;
+}
+
+static ssize_t conn_handle_kget(ECPConnection *conn, unsigned char ptype, unsigned char *payload, ssize_t size) {
+    ecp_conn_handler_t *handler = conn->handler ? conn->handler->f[ptype] : NULL;
+
+    if (conn->out) {
+#ifdef ECP_WITH_PTHREAD
+        pthread_mutex_lock(&conn->mutex);
+#endif
+        int conn_is_open = ecp_conn_is_open(conn);
+#ifdef ECP_WITH_PTHREAD
+        pthread_mutex_unlock(&conn->mutex);
+#endif
+
+        if (size < 0) {
+            if (!conn_is_open) handler = conn->handler ? conn->handler->f[ECP_PTYPE_OPEN] : handler;
+            return handler ? handler(conn, ptype, payload, size) : 0;
+        }
+
+        if (size < ECP_ECDH_SIZE_KEY+1) return ECP_ERR;
+
+        int rv = ecp_conn_dhkey_new_pub(conn, payload[0], payload+1);
+        if (!rv && !conn_is_open) {
+            ECPTimerItem ti;
+            ssize_t _rv = 0;
+
+            rv = ecp_timer_item_init(&ti, conn, ECP_PTYPE_OPEN, 3, 500);
+            if (!rv) rv = ecp_timer_push(conn, &ti);
+            if (!rv) _rv = ecp_send(conn, ECP_PTYPE_OPEN, NULL, 0);
+            if (_rv < 0) rv = _rv;
+        }
+
+        return handler ? handler(conn, ptype, rv ? NULL : payload, rv ? rv : size) : ECP_ECDH_SIZE_KEY+1;
+    } else {
+        unsigned char payload[ECP_SIZE_PLD(ECP_ECDH_SIZE_KEY+1)];
+        unsigned char *buf = ecp_pld_get_buf(payload);
+        ecp_pld_set_type(payload, ECP_PTYPE_KGET);
+
+        if (size < 0) return ECP_ERR;
+
+        int rv = ecp_conn_dhkey_get_curr(conn, buf, buf+1);
+        if (rv) return rv;
+        
+        ssize_t _rv = ecp_pld_send(conn, payload, sizeof(payload));
+
+        return handler ? handler(conn, ptype, payload, size) : 0;
+    }
+
+    return ECP_ERR;
+}
+ 
+static ssize_t conn_handle_kput(ECPConnection *conn, unsigned char ptype, unsigned char *payload, ssize_t size) {
+    ecp_conn_handler_t *handler = conn->handler ? conn->handler->f[ptype] : NULL;
+
+    if (conn->out) {
+        return handler ? handler(conn, ptype, payload, size) : 0;
+    } else {
+        if (size < ECP_ECDH_SIZE_KEY+1) return ECP_ERR;
+
+        int rv = ecp_conn_dhkey_new_pub(conn, payload[0], payload+1);
+        if (rv) return rv;
+
+        ssize_t _rv = ecp_send(conn, ECP_PTYPE_KPUT, NULL, 0);
+
+        return handler ? handler(conn, ptype, payload, size) : ECP_ECDH_SIZE_KEY+1;
+    }
+
+    return ECP_ERR;
+}
+
+int ecp_conn_create(ECPConnection *conn, ECPSocket *sock) {
+    int i;
+    
+    if (conn == NULL) return ECP_ERR;
+    if (sock == NULL) return ECP_ERR;
+
+    memset(conn, 0, sizeof(ECPConnection));
+
+    conn->key_curr = ECP_ECDH_IDX_INV;
+    conn->key_idx_curr = ECP_ECDH_IDX_INV;
+    conn->remote.key_curr = ECP_ECDH_IDX_INV;
+    memset(conn->key_idx, ECP_ECDH_IDX_INV, sizeof(conn->key_idx));
+    memset(conn->key_idx_map, ECP_ECDH_IDX_INV, sizeof(conn->key_idx_map));
+    for (i=0; i<ECP_MAX_NODE_KEY; i++) {
+        conn->remote.key[i].idx = ECP_ECDH_IDX_INV;
+    }
+    memset(conn->remote.key_idx_map, ECP_ECDH_IDX_INV, sizeof(conn->remote.key_idx_map));
+
+    conn->sock = sock;
+
+#ifdef ECP_WITH_PTHREAD
+    int rv = pthread_mutex_init(&conn->mutex, NULL);
+    if (rv) return ECP_ERR;
+
+    rv = ecp_conn_msgq_create(conn);
+    if (rv) {
+        pthread_mutex_destroy(&conn->mutex);
+        return ECP_ERR;
+    }
+#endif
+
+    return ECP_OK;
+}
+
+void ecp_conn_destroy(ECPConnection *conn) {
+#ifdef ECP_WITH_PTHREAD
+    ecp_conn_msgq_destroy(conn);
+    pthread_mutex_destroy(&conn->mutex);
+#endif
+}
+
+int ecp_conn_register(ECPConnection *conn) {
+    ECPSocket *sock = conn->sock;
+
+    conn->flags |= ECP_CONN_FLAG_REG;
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&sock->conn.mutex);
+#endif
+    int rv = ctable_insert(conn);
+    if (rv) conn->flags &= ~ECP_CONN_FLAG_REG;
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&sock->conn.mutex);
+#endif
+
+    return rv;
+}
+
+int ecp_conn_unregister(ECPConnection *conn, unsigned int timeout) {
+    ECPSocket *sock = conn->sock;
+    int refcount = 0;
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&sock->conn.mutex);
+    pthread_mutex_lock(&conn->mutex);
+#endif
+    if (ecp_conn_is_reg(conn)) {
+        ctable_remove(conn);
+        conn->flags &= ~ECP_CONN_FLAG_REG;
+    } 
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&conn->mutex);
+    pthread_mutex_unlock(&sock->conn.mutex);
+#endif
+
+    ecp_timer_remove(conn);
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&conn->mutex);
+    refcount = conn->refcount;
+    pthread_mutex_unlock(&conn->mutex);
+    
+    if (timeout && refcount) {
+        sock->ctx->tm.sleep_ms(timeout);
+        pthread_mutex_lock(&conn->mutex);
+        refcount = conn->refcount;
+        pthread_mutex_unlock(&conn->mutex);
+    }
+
+    if (refcount) return ECP_ERR_TIMEOUT;
+#endif
+
+    return ECP_OK;
+}
+
+static int _conn_kget_send(ECPConnection *conn, ECPTimerItem *ti) {
+    unsigned char payload[ECP_MIN_PLD];
+    ecp_pld_set_type(payload, ECP_PTYPE_KGET);
+    ssize_t rv = ecp_pld_send_wkey(conn, ECP_ECDH_IDX_PERMA, ECP_ECDH_IDX_INV, payload, sizeof(payload));
+    if (rv < 0) return rv;
+    return ECP_OK;
+}
+
+int ecp_conn_open(ECPConnection *conn, ECPNode *node, ECPConnHandler *handler) {
+    int rv = ECP_OK;
+    ECPDHKey key;
+    ECPContext *ctx = conn->sock->ctx;
+    
+    if (conn == NULL) return ECP_ERR;
+    if (node == NULL) return ECP_ERR;
+    if (ctx->rng == NULL) return ECP_ERR_RNG;
+
+    conn->out = 1;
+    conn->node = *node;
+    conn->handler = handler;
+    rv = ctx->rng(conn->nonce, ECP_AEAD_SIZE_NONCE);
+    if (!rv) rv = ecp_dhkey_generate(ctx, &key);
+    if (!rv) rv = conn_dhkey_new_pair(conn, &key);
+    if (!rv) rv = conn_dhkey_new_pub_local(conn, conn->key_curr);
+    if (!rv) rv = ecp_conn_register(conn);
+    if (rv) return rv;
+    
+    rv = ecp_timer_send(conn, _conn_kget_send, ECP_PTYPE_KGET, 3, 500);
+    if (rv) {
+        ecp_conn_unregister(conn, 0);
+        return rv;
+    }
+
+    return ECP_OK;
+}
+
+int ecp_conn_close(ECPConnection *conn, unsigned int timeout) {
+    return ecp_conn_unregister(conn, timeout);
+}
+
+int ecp_conn_hander_init(ECPConnHandler *handler) {
+    memset(handler, 0, sizeof(ECPConnHandler));
+    return ECP_OK;
+}
+
+int ecp_conn_dhkey_get_curr(ECPConnection *conn, unsigned char *idx, unsigned char *public) {
+    ECPSocket *sock = conn->sock;
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&conn->mutex);
+#endif
+
+    *idx = conn->key_curr;
+    if (conn->key_curr != ECP_ECDH_IDX_INV) sock->ctx->cr.dh_pub_to_buf(public, &conn->key[conn->key_curr].public);
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&conn->mutex);
+#endif
+    
+    if (*idx == ECP_ECDH_IDX_INV) return ecp_sock_dhkey_get_curr(sock, idx, public);
+    return ECP_OK;
+}
+    
+static int _conn_kput_send(ECPConnection *conn, ECPTimerItem *ti) {
+    unsigned char payload[ECP_SIZE_PLD(ECP_ECDH_SIZE_KEY+1)];
+    unsigned char *buf = ecp_pld_get_buf(payload);
+    ecp_pld_set_type(payload, ECP_PTYPE_KPUT);
+
+    int rv = ecp_conn_dhkey_get_curr(conn, buf, buf+1);
+    if (rv) return rv;
+
+    ssize_t _rv = ecp_pld_send(conn, payload, sizeof(payload));
+    if (_rv < 0) return _rv;
+    
+    return ECP_OK;
+}
+
+int ecp_conn_dhkey_new(ECPConnection *conn) {
+    ECPSocket *sock = conn->sock;
+    ECPDHKey new_key;
+    unsigned char key_curr;
+    int rv;
+    
+    rv = ecp_dhkey_generate(sock->ctx, &new_key);
+    if (rv) return rv;
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&sock->conn.mutex);
+    pthread_mutex_lock(&conn->mutex);
+#endif
+    rv = conn_dhkey_new_pair(conn, &new_key);
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&conn->mutex);
+    pthread_mutex_unlock(&sock->conn.mutex);
+#endif
+
+    if (!rv) rv = ecp_timer_send(conn, _conn_kput_send, ECP_PTYPE_KPUT, 3, 500);
+        
+    return rv;
+}
+
+int ecp_conn_dhkey_new_pub(ECPConnection *conn, unsigned char idx, unsigned char *public) {
+    ECPSocket *sock = conn->sock;
+    int rv;
+    
+    if (conn == NULL) return ECP_ERR;
+    if (public == NULL) return ECP_ERR;
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&sock->conn.mutex);
+    pthread_mutex_lock(&conn->mutex);
+#endif
+    rv = conn_dhkey_new_pub_remote(conn, idx, public);
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&conn->mutex);
+    pthread_mutex_unlock(&sock->conn.mutex);
+#endif
+    if (rv == ECP_ERR_ECDH_KEY_DUP) rv = ECP_OK;
+
+    return rv;
+}
+
+ssize_t ecp_conn_pack(ECPConnection *conn, ECPNetAddr *addr, unsigned char *packet, size_t pkt_size, unsigned char s_idx, unsigned char c_idx, unsigned char *payload, size_t payload_size) {
+    ecp_aead_key_t shsec;
+    ecp_dh_public_t public;
+    unsigned char nonce[ECP_AEAD_SIZE_NONCE];
+    unsigned char seq[ECP_SIZE_SEQ];
+    int rv = ECP_OK;
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&conn->mutex);
+#endif
+    if (s_idx == ECP_ECDH_IDX_INV) {
+        if (conn->out) {
+            if (conn->remote.key_curr != ECP_ECDH_IDX_INV) s_idx = conn->remote.key[conn->remote.key_curr].idx;
+        } else {
+            if (conn->key_idx_curr != ECP_ECDH_IDX_INV) s_idx = conn->key_idx[conn->key_idx_curr];
+        }
+    }
+    if (c_idx == ECP_ECDH_IDX_INV) {
+        if (conn->out) {
+            if (conn->key_idx_curr != ECP_ECDH_IDX_INV) c_idx = conn->key_idx[conn->key_idx_curr];
+        } else {
+            if (conn->remote.key_curr != ECP_ECDH_IDX_INV) c_idx = conn->remote.key[conn->remote.key_curr].idx;
+        }
+    }
+    rv = conn_shsec_get(conn, s_idx, c_idx, &shsec);
+    if (!rv) memcpy(nonce, conn->nonce, sizeof(nonce));
+    if (!rv) {
+        if (conn->out) {
+            ECPDHKey *key = conn_dhkey_get(conn, c_idx);
+
+            if ((key == NULL) || !key->valid) rv = ECP_ERR_ECDH_IDX;
+            if (!rv) memcpy(&public, &key->public, sizeof(public));
+        } else {
+            memcpy(&public, &conn->remote.key[conn->remote.key_curr].public, sizeof(public));
+        }
+
+    }
+    if (!rv) {
+        conn->seq_out++;
+        seq[0] = (conn->seq_out & 0xFF000000) >> 24;
+        seq[1] = (conn->seq_out & 0x00FF0000) >> 16;
+        seq[2] = (conn->seq_out & 0x0000FF00) >> 8;
+        seq[3] = (conn->seq_out & 0x000000FF);
+        *addr = conn->node.addr;
+    }
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&conn->mutex);
+#endif
+    
+    if (rv) return rv;
+    
+    ssize_t _rv = ecp_pack(conn->sock->ctx, packet, pkt_size, s_idx, c_idx, &public, &shsec, nonce, seq, payload, payload_size);
+    if (_rv < 0) return _rv;
+    
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&conn->mutex);
+#endif
+    memcpy(conn->nonce, nonce, sizeof(conn->nonce));
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&conn->mutex);
+#endif
+
+    return _rv;
+}
+
+ssize_t ecp_pkt_handle_err(ECPSocket *sock, ECPNetAddr *addr, unsigned char *packet, size_t pkt_size) {
+    unsigned char s_idx;
+    unsigned char c_idx;
+    unsigned char l_idx = ECP_ECDH_IDX_INV;
+    unsigned char nonce[ECP_AEAD_SIZE_NONCE];
+    ecp_aead_key_t shsec;
+    ecp_dh_public_t public;
+    ecp_dh_private_t private;
+    unsigned char payload[ECP_MAX_PLD];
+    ECPConnection *conn = NULL;
+    ECPDHKey *key = NULL;
+    int rv = ECP_OK;
+    ssize_t _rv = 0;
+    uint32_t c_seq, p_seq, n_seq, seq_bitmap;
+    ssize_t pld_size, cnt_size, proc_size;
+    
+    s_idx = (packet[ECP_SIZE_PROTO] & 0xF0) >> 4;
+    c_idx = (packet[ECP_SIZE_PROTO] & 0x0F);
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&sock->conn.mutex);
+#endif
+
+    conn = ctable_search(sock, c_idx, packet+ECP_SIZE_PROTO+1, NULL);
+    if (conn && !conn->out && (s_idx == ECP_ECDH_IDX_PERMA)) conn = NULL;
+
+#ifdef ECP_WITH_PTHREAD
+    if (conn) pthread_mutex_lock(&conn->mutex);
+    pthread_mutex_unlock(&sock->conn.mutex);
+#endif
+
+    if (conn) {
+        rv = conn_shsec_get(conn, s_idx, c_idx, &shsec);
+        if (rv == ECP_ERR_ECDH_IDX_LOCAL) {
+            rv = ECP_OK;
+            l_idx = conn->out ? c_idx : s_idx;
+            key = conn_dhkey_get(conn, l_idx);
+            if ((key == NULL) || !key->valid) rv = ECP_ERR_ECDH_IDX;
+        }
+    } else {
+        if (s_idx == ECP_ECDH_IDX_PERMA) {
+            key = &sock->key_perma;
+        } else {
+            l_idx = s_idx;
+            if (l_idx < ECP_MAX_SOCK_KEY) key = &sock->key[l_idx];
+        }
+        if ((key == NULL) || !key->valid) rv = ECP_ERR_ECDH_IDX;
+    }
+
+    if (!rv && key) memcpy(&private, &key->private, sizeof(private));
+
+    if (!rv && conn) {
+        c_seq = conn->seq_in;
+        seq_bitmap = conn->seq_in_bitmap;
+        conn->refcount++;
+    }
+
+#ifdef ECP_WITH_PTHREAD
+    if (conn) pthread_mutex_unlock(&conn->mutex);
+#endif
+
+    if (rv) return rv;
+
+    if (key) {
+        sock->ctx->cr.dh_pub_from_buf(&public, packet+ECP_SIZE_PROTO+1);
+        sock->ctx->cr.dh_shsec(&shsec, &public, &private);
+    }
+
+    memset(private, 0, sizeof(private));
+
+    pld_size = sock->ctx->cr.aead_dec(payload, ECP_MAX_PLD, packet+ECP_SIZE_PKT_HDR, pkt_size-ECP_SIZE_PKT_HDR, &shsec, packet+ECP_SIZE_PROTO+1+ECP_ECDH_SIZE_KEY);
+    if (pld_size < ECP_MIN_PLD) rv = ECP_ERR_DECRYPT;
+    if (rv) goto pkt_handle_err;
+
+    p_seq = \
+        (payload[0] << 24) | \
+        (payload[1] << 16) | \
+        (payload[2] << 8)  | \
+        (payload[3]);
+
+    memcpy(nonce, packet+ECP_SIZE_PKT_HDR, sizeof(nonce));
+
+    if (conn == NULL) {
+        if (payload[ECP_SIZE_SEQ] == ECP_PTYPE_OPEN) {
+            rv = conn_new(&conn, sock, s_idx, c_idx, packet+ECP_SIZE_PROTO+1, &shsec, payload+ECP_SIZE_PLD_HDR, pld_size-ECP_SIZE_PLD_HDR);
+            if (rv) return rv;
+
+            seq_bitmap = 0;
+            n_seq = p_seq;
+        } else if (payload[ECP_SIZE_SEQ] == ECP_PTYPE_KGET) {
+            unsigned char _payload[ECP_SIZE_PLD(ECP_ECDH_SIZE_KEY+1)];
+            unsigned char *buf = ecp_pld_get_buf(_payload);
+            ecp_pld_set_type(_payload, ECP_PTYPE_KGET);
+
+            rv = ecp_sock_dhkey_get_curr(sock, buf, buf+1);
+            if (!rv) {
+                ssize_t _rv = ecp_pld_send_raw(sock, addr, s_idx, c_idx, &public, &shsec, nonce, payload, _payload, sizeof(_payload));
+                if (_rv < 0) rv = _rv;
+            }
+            return ECP_MIN_PKT;
+        } else {
+            return ECP_ERR_CONN_NOT_FOUND;
+        }
+    } else {
+        /*
+        if ((c_seq > p_seq) && (c_seq - p_seq >= 32)) rv = ECP_ERR_SEQ;
+        if ((p_seq > c_seq) && (p_seq - c_seq > 32)) rv = ECP_ERR_SEQ;
+
+        if (rv) goto pkt_handle_err;
+    
+        if (p_seq <= c_seq) {
+            uint32_t p_bit = (uint32_t)1 << (c_seq - p_seq);
+            if (seq_bitmap & p_bit) rv = ECP_ERR_SEQ;
+            if (rv) goto pkt_handle_err;
+            seq_bitmap = seq_bitmap | p_bit;
+            n_seq = c_seq;
+        } else {
+            seq_bitmap = seq_bitmap << (p_seq - c_seq);
+            seq_bitmap = seq_bitmap | 1;
+            n_seq = p_seq;
+        }
+        */
+        
+        if (key) {
+#ifdef ECP_WITH_PTHREAD
+            pthread_mutex_lock(&conn->mutex);
+#endif
+            rv = conn_dhkey_new_pub_local(conn, l_idx);
+            if (!rv) rv = conn_shsec_set(conn, s_idx, c_idx, &shsec);
+#ifdef ECP_WITH_PTHREAD
+            pthread_mutex_unlock(&conn->mutex);
+#endif
+            if (rv) goto pkt_handle_err;
+        }
+    }
+
+    if (conn == NULL) return ECP_ERR;
+    
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&conn->mutex);
+#endif
+    memcpy(conn->nonce, nonce, sizeof(conn->nonce));
+    conn->node.addr = *addr;
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&conn->mutex);
+#endif
+
+    cnt_size = pld_size-ECP_SIZE_SEQ;
+    proc_size = ecp_pld_handle(conn, payload+pld_size-cnt_size, cnt_size);
+    if (proc_size < 0) rv = ECP_ERR_HANDLE;
+    if (!rv) cnt_size -= proc_size;
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&conn->mutex);
+    if (!rv && (cnt_size > 0)) {
+        proc_size = ecp_conn_msgq_push(conn, payload+pld_size-cnt_size, cnt_size);
+        if (proc_size < 0) rv = ECP_ERR_HANDLE;
+        if (!rv) cnt_size -= proc_size;
+    }
+#endif
+    if (!rv) {
+        conn->seq_in = n_seq;
+        conn->seq_in_bitmap = seq_bitmap;
+    }
+    conn->refcount--;
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&conn->mutex);
+#endif
+
+    if (rv) return rv;
+    return ECP_SIZE_PKT_HDR+ECP_AEAD_SIZE_TAG+pld_size-cnt_size;
+    
+pkt_handle_err:
+    if (conn == NULL) return rv;
+
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&conn->mutex);
+#endif
+    conn->refcount--;
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_unlock(&conn->mutex);
+#endif
+
+    return rv;
+}
+
+ssize_t ecp_pkt_send(ECPSocket *sock, ECPNetAddr *addr, unsigned char *packet, size_t pkt_size) {
+    ssize_t rv = sock->ctx->tr.send(&sock->sock, packet, pkt_size, addr);
+    if (rv < 0) return rv;
+    if (rv < ECP_MIN_PKT) return ECP_ERR_SEND;
+    
+    return rv;
+}
+
+ssize_t ecp_pkt_recv(ECPSocket *sock, ECPNetAddr *addr, unsigned char *packet, size_t pkt_size) {
+    ssize_t rv = sock->ctx->tr.recv(&sock->sock, packet, pkt_size, addr);
+    if (rv < 0) return rv;
+    if (rv < ECP_MIN_PKT) return ECP_ERR_RECV;
+
+    return rv;
+}
+
+ssize_t ecp_pld_handle(ECPConnection *conn, unsigned char *payload, size_t payload_size) {
+    ecp_conn_handler_t *handler = NULL;
+    ssize_t rv = 0;
+    unsigned char ptype = 0;
+    size_t rem_size = payload_size;
+    ECPSocket *sock = conn->sock;    
+    
+    while (rem_size) {
+        ptype = payload[0];
+        payload++;
+        rem_size--;
+
+        if (ptype >= ECP_MAX_PTYPE) return ECP_ERR_MAX_PTYPE;
+        if (rem_size < ECP_MIN_MSG) return ECP_ERR_MIN_MSG;
+
+        ecp_timer_pop(conn, ptype);
+        handler = (ptype < ECP_MAX_PTYPE_SYS) && sock->handler[ptype] ? sock->handler[ptype] : (conn->handler ? conn->handler->f[ptype] : NULL);
+        if (handler) {
+            rv = handler(conn, ptype, payload, rem_size);
+            if (rv == 0) rv = rem_size;
+            if (rv < 0) return rv;
+            if (rv > rem_size) return ECP_ERR;
+
+            rem_size -= rv;
+        } else {
+            return payload_size-rem_size-1;
+        }
+    }
+
+    return payload_size;
+}
+
+unsigned char *ecp_pld_get_buf(unsigned char *payload) {
+    return payload+ECP_SIZE_PLD_HDR;
+}
+
+void ecp_pld_set_type(unsigned char *payload, unsigned char ptype) {
+    payload[ECP_SIZE_SEQ] = ptype;
+}
+
+ssize_t ecp_pld_send(ECPConnection *conn, unsigned char *payload, size_t payload_size) {
+    return ecp_pld_send_wkey(conn, ECP_ECDH_IDX_INV, ECP_ECDH_IDX_INV, payload, payload_size);
+}
+
+ssize_t ecp_pld_send_wkey(ECPConnection *conn, unsigned char s_idx, unsigned char c_idx, unsigned char *payload, size_t payload_size) {
+    ECPSocket *sock = conn->sock;
+    ECPNetAddr addr;
+    unsigned char packet[ECP_MAX_PKT];
+    ssize_t rv;
+
+    rv = ecp_conn_pack(conn, &addr, packet, ECP_MAX_PKT, s_idx, c_idx, payload, payload_size);
+    if (rv < 0) return rv;
+    
+    rv = ecp_pkt_send(sock, &addr, packet, rv);
+    if (rv < 0) return rv;
+    
+    return rv-ECP_SIZE_PKT_HDR-ECP_AEAD_SIZE_TAG;
+}
+
+ssize_t ecp_pld_send_raw(ECPSocket *sock, ECPNetAddr *addr, unsigned char s_idx, unsigned char c_idx, ecp_dh_public_t *public, ecp_aead_key_t *shsec, unsigned char *nonce, unsigned char *seq, unsigned char *payload, size_t payload_size) {
+    unsigned char packet[ECP_MAX_PKT];
+    ssize_t rv;
+
+    rv = ecp_pack(sock->ctx, packet, ECP_MAX_PKT, s_idx, c_idx, public, shsec, nonce, seq, payload, payload_size);
+    if (rv < 0) return rv;
+    
+    rv = ecp_pkt_send(sock, addr, packet, rv);
+    if (rv < 0) return rv;
+    
+    return rv-ECP_SIZE_PKT_HDR-ECP_AEAD_SIZE_TAG;
+}
+    
+ssize_t ecp_send(ECPConnection *conn, unsigned char ptype, unsigned char *payload, size_t payload_size) {
+    ssize_t rv;
+    
+    if (payload == NULL) {
+        unsigned char _payload[ECP_MIN_PLD];
+        ecp_pld_set_type(_payload, ptype);
+        rv = ecp_pld_send_wkey(conn, ECP_ECDH_IDX_INV, ECP_ECDH_IDX_INV, _payload, sizeof(_payload));
+    } else {
+        ecp_pld_set_type(payload, ptype);
+        rv = ecp_pld_send_wkey(conn, ECP_ECDH_IDX_INV, ECP_ECDH_IDX_INV, payload, ECP_SIZE_PLD(payload_size));
+    }
+    return rv-ECP_SIZE_PLD_HDR;
+}
+
+ssize_t ecp_receive(ECPConnection *conn, unsigned char ptype, unsigned char *payload, size_t payload_size, unsigned int timeout) {
+#ifdef ECP_WITH_PTHREAD
+    pthread_mutex_lock(&conn->mutex);
+    ssize_t rv = ecp_conn_msgq_pop(conn, ptype, payload, payload_size, timeout);
+    pthread_mutex_unlock(&conn->mutex);
+    return rv;
+#else
+    return ECP_ERR_NOT_IMPLEMENTED;
+#endif
+}
+
+static int recv_p(ECPSocket *sock) {
+    ECPNetAddr addr;
+    unsigned char packet[ECP_MAX_PKT];
+    
+    ssize_t rv = ecp_pkt_recv(sock, &addr, packet, ECP_MAX_PKT);
+    if (rv < 0) return rv;
+    
+    rv = ecp_pkt_handle(sock, &addr, packet, rv);
+    if (rv < 0) return rv;
+    
+    return ECP_OK;
+}
+
+int ecp_receiver(ECPSocket *sock) {
+    unsigned int next = 0;
+    sock->running = 1;
+    while(sock->running) {
+        int rv = sock->ctx->tr.poll(&sock->sock, next ? next : sock->poll_timeout);
+        if (rv == 1) {
+            rv = recv_p(sock);
+            DPRINT(rv, "ERR:recv_p - RV:%d\n", rv);
+        }
+        next = ecp_timer_exe(sock);
+    }
+    return ECP_OK;
+}
+
+int ecp_start_receiver(ECPSocket *sock) {
+#ifdef ECP_WITH_PTHREAD
+    int rv = pthread_create(&sock->rcvr_thd, NULL, (void *(*)(void *))ecp_receiver, sock);
+    if (rv) return ECP_ERR;
+    return ECP_OK;
+#else
+    return ECP_ERR_NOT_IMPLEMENTED;
+#endif
+}
+
+int ecp_stop_receiver(ECPSocket *sock) {
+    sock->running = 0;
+#ifdef ECP_WITH_PTHREAD
+    int rv = pthread_join(sock->rcvr_thd, NULL);
+    if (rv) return ECP_ERR;
+    return ECP_OK;
+#else
+    return ECP_ERR_NOT_IMPLEMENTED;
+#endif
+}