PktOut *ssh2_portfwd_chanopen(
    struct ssh2_connection_state *s, struct ssh2_channel *c,
    const char *hostname, int port,
    const char *description, const SocketPeerInfo *pi)
{
    PacketProtocolLayer *ppl = &s->ppl; /* for ppl_logevent */
    PktOut *pktout;

    /*
     * In server mode, this function is called by portfwdmgr in
     * response to PortListeners that were set up by calling
     * portfwdmgr_listen, which means that the hostname and port
     * parameters will identify the listening socket on which a
     * connection just came in.
     */

    if (pi && pi->log_text)
        ppl_logevent("Forwarding connection to listening port %s:%d from %s",
                     hostname, port, pi->log_text);
    else
        ppl_logevent("Forwarding connection to listening port %s:%d",
                     hostname, port);

    pktout = ssh2_chanopen_init(c, "forwarded-tcpip");
    put_stringz(pktout, hostname);
    put_uint32(pktout, port);
    put_stringz(pktout, (pi && pi->addr_text ? pi->addr_text : "0.0.0.0"));
    put_uint32(pktout, (pi && pi->port >= 0 ? pi->port : 0));

    return pktout;
}

void zmq::amqp_marshaller_t::queue_declare_ok (
            uint16_t channel_,
            const i_amqp::shortstr_t queue_,
            uint32_t message_count_,
            uint32_t consumer_count_)
{
    unsigned char *args = (unsigned char*) malloc (i_amqp::frame_min_size);
    assert (args);

    size_t offset = 0;
    assert (offset + sizeof (uint8_t) + queue_.size <=
        i_amqp::frame_min_size);
    put_uint8 (args + offset, queue_.size);
    offset += sizeof (uint8_t);
    memcpy (args + offset, queue_.data, queue_.size);
    offset += queue_.size;
    assert (offset + sizeof (uint32_t) <= i_amqp::frame_min_size);
    put_uint32 (args + offset, message_count_);
    offset += sizeof (uint32_t);
    assert (offset + sizeof (uint32_t) <= i_amqp::frame_min_size);
    put_uint32 (args + offset, consumer_count_);
    offset += sizeof (uint32_t);

    command_t cmd = {
        channel_,
        i_amqp::queue_id,
        i_amqp::queue_declare_ok_id,
        args,
        offset
    };
    command_queue.push (cmd);
}

/*
 * Read from a file. Returns the number of bytes read, or -1 on an
 * error, or possibly 0 if EOF. (I'm not entirely sure whether it
 * will return 0 on EOF, or return -1 and store SSH_FX_EOF in the
 * error indicator. It might even depend on the SFTP server.)
 */
struct sftp_request *fxp_read_send(struct fxp_handle *handle,
				   uint64_t offset, int len)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_READ);
    put_uint32(pktout, req->id);
    put_string(pktout, handle->hstring, handle->hlen);
    put_uint64(pktout, offset);
    put_uint32(pktout, len);
    sftp_send(pktout);

    return req;
}

bool zmq::router_t::identify_peer (pipe_t *pipe_)
{
    msg_t msg;
    blob_t identity;
    bool ok;

    if (options.raw_sock) { //  Always assign identity for raw-socket
        unsigned char buf [5];
        buf [0] = 0;
        put_uint32 (buf + 1, next_peer_id++);
        identity = blob_t (buf, sizeof buf);
        unsigned int i = 0;  // Store identity to allow use of raw socket as client
        for (blob_t::iterator it = identity.begin(); it != identity.end(); it++) options.identity[i++] = *it;
        options.identity_size = i;
    }
    else {
        msg.init ();
        ok = pipe_->read (&msg);
        if (!ok)
            return false;

        if (msg.size () == 0) {
            //  Fall back on the auto-generation
            unsigned char buf [5];
            buf [0] = 0;
            put_uint32 (buf + 1, next_peer_id++);
            identity = blob_t (buf, sizeof buf);
            msg.close ();
        }
        else {
            identity = blob_t ((unsigned char*) msg.data (), msg.size ());
            outpipes_t::iterator it = outpipes.find (identity);
            msg.close ();

            //  Ignore peers with duplicate ID.
            if (it != outpipes.end ())
                return false;
        }
    }

    pipe_->set_identity (identity);
    //  Add the record into output pipes lookup table
    outpipe_t outpipe = {pipe_, true};
    ok = outpipes.insert (outpipes_t::value_type (identity, outpipe)).second;
    zmq_assert (ok);

    return true;
}

int zmq::gssapi_mechanism_base_t::produce_initiate (msg_t *msg_, void *token_value_, size_t token_length_)
{
    zmq_assert (token_value_);
    zmq_assert (token_length_ <= 0xFFFFFFFFUL);

    const size_t command_size = 9 + 4 + token_length_;

    const int rc = msg_->init_size (command_size);
    errno_assert (rc == 0);

    uint8_t *ptr = static_cast <uint8_t *> (msg_->data ());

    // Add command string
    memcpy (ptr, "\x08INITIATE", 9);
    ptr += 9;

    // Add token length
    put_uint32 (ptr, static_cast <uint32_t> (token_length_));
    ptr += 4;

    // Add token value
    memcpy (ptr, token_value_, token_length_);
    ptr += token_length_;

    return 0;
}

static void oaep_mask(const ssh_hashalg *h, void *seed, int seedlen,
		      void *vdata, int datalen)
{
    unsigned char *data = (unsigned char *)vdata;
    unsigned count = 0;

    while (datalen > 0) {
        int i, max = (datalen > h->hlen ? h->hlen : datalen);
        ssh_hash *s;
        unsigned char hash[MAX_HASH_LEN];

	assert(h->hlen <= MAX_HASH_LEN);
        s = ssh_hash_new(h);
        put_data(s, seed, seedlen);
        put_uint32(s, count);
        ssh_hash_final(s, hash);
        count++;

        for (i = 0; i < max; i++)
            data[i] ^= hash[i];

        data += max;
        datalen -= max;
    }
}

static void rsa2_sign(ssh_key *key, ptrlen data,
                      unsigned flags, BinarySink *bs)
{
    RSAKey *rsa = container_of(key, RSAKey, sshk);
    unsigned char *bytes;
    size_t nbytes;
    mp_int *in, *out;
    const ssh_hashalg *halg;
    const char *sign_alg_name;

    halg = rsa2_hash_alg_for_flags(flags, &sign_alg_name);

    nbytes = (mp_get_nbits(rsa->modulus) + 7) / 8;

    bytes = rsa_pkcs1_signature_string(nbytes, halg, data);
    in = mp_from_bytes_be(make_ptrlen(bytes, nbytes));
    smemclr(bytes, nbytes);
    sfree(bytes);

    out = rsa_privkey_op(in, rsa);
    mp_free(in);

    put_stringz(bs, sign_alg_name);
    nbytes = (mp_get_nbits(out) + 7) / 8;
    put_uint32(bs, nbytes);
    for (size_t i = 0; i < nbytes; i++)
	put_byte(bs, mp_get_byte(out, nbytes - 1 - i));

    mp_free(out);
}

void zmq::stream_t::identify_peer (pipe_t *pipe_)
{
    //  Always assign identity for raw-socket
    unsigned char buffer [5];
    buffer [0] = 0;
    blob_t identity;
    if (connect_rid.length ()) {
        identity = blob_t ((unsigned char*) connect_rid.c_str(),
            connect_rid.length ());
        connect_rid.clear ();
        outpipes_t::iterator it = outpipes.find (identity);
        zmq_assert (it == outpipes.end ());
    }
    else {
        put_uint32 (buffer + 1, next_rid++);
        identity = blob_t (buffer, sizeof buffer);
        memcpy (options.identity, identity.data (), identity.size ());
        options.identity_size = (unsigned char) identity.size ();
    }
    pipe_->set_identity (identity);
    //  Add the record into output pipes lookup table
    outpipe_t outpipe = {pipe_, true};
    const bool ok = outpipes.insert (
        outpipes_t::value_type (identity, outpipe)).second;
    zmq_assert (ok);
}

static void default_reply_name_count(SftpReplyBuilder *reply, unsigned count)
{
    DefaultSftpReplyBuilder *d =
        container_of(reply, DefaultSftpReplyBuilder, rb);
    d->pkt->type = SSH_FXP_NAME;
    put_uint32(d->pkt, count);
}

void zmq::stream_t::identify_peer (pipe_t *pipe_)
{
    //  Always assign routing id for raw-socket
    unsigned char buffer[5];
    buffer[0] = 0;
    blob_t routing_id;
    if (connect_routing_id.length ()) {
        routing_id.set ((unsigned char *) connect_routing_id.c_str (),
                        connect_routing_id.length ());
        connect_routing_id.clear ();
        outpipes_t::iterator it = outpipes.find (routing_id);
        zmq_assert (it == outpipes.end ());
    } else {
        put_uint32 (buffer + 1, next_integral_routing_id++);
        routing_id.set (buffer, sizeof buffer);
        memcpy (options.routing_id, routing_id.data (), routing_id.size ());
        options.routing_id_size = (unsigned char) routing_id.size ();
    }
    pipe_->set_router_socket_routing_id (routing_id);
    //  Add the record into output pipes lookup table
    outpipe_t outpipe = {pipe_, true};
    const bool ok =
      outpipes.ZMQ_MAP_INSERT_OR_EMPLACE (ZMQ_MOVE (routing_id), outpipe)
        .second;
    zmq_assert (ok);
}

static void eddsa_openssh_blob(ssh_key *key, BinarySink *bs)
{
    struct eddsa_key *ek = container_of(key, struct eddsa_key, sshk);
    assert(ek->curve->type == EC_EDWARDS);

    /* Encode the public and private points as strings */
    strbuf *pub_sb = strbuf_new();
    put_epoint(pub_sb, ek->publicKey, ek->curve, false);
    ptrlen pub = make_ptrlen(pub_sb->s + 4, pub_sb->len - 4);

    strbuf *priv_sb = strbuf_new_nm();
    put_mp_le_unsigned(priv_sb, ek->privateKey);
    ptrlen priv = make_ptrlen(priv_sb->s + 4, priv_sb->len - 4);

    put_stringpl(bs, pub);

    /* Encode the private key as the concatenation of the
     * little-endian key integer and the public key again */
    put_uint32(bs, priv.len + pub.len);
    put_datapl(bs, priv);
    put_datapl(bs, pub);

    strbuf_free(pub_sb);
    strbuf_free(priv_sb);
}

static void BinarySink_put_mp_le_unsigned(BinarySink *bs, mp_int *x)
{
    size_t bytes = (mp_get_nbits(x) + 7) / 8;

    put_uint32(bs, bytes);
    for (size_t i = 0; i < bytes; ++i)
        put_byte(bs, mp_get_byte(x, i));
}

static void default_reply_ok(SftpReplyBuilder *reply)
{
    DefaultSftpReplyBuilder *d =
        container_of(reply, DefaultSftpReplyBuilder, rb);
    d->pkt->type = SSH_FXP_STATUS;
    put_uint32(d->pkt, SSH_FX_OK);
    put_stringz(d->pkt, "");
}

static void default_reply_error(
    SftpReplyBuilder *reply, unsigned code, const char *msg)
{
    DefaultSftpReplyBuilder *d =
        container_of(reply, DefaultSftpReplyBuilder, rb);
    d->pkt->type = SSH_FXP_STATUS;
    put_uint32(d->pkt, code);
    put_stringz(d->pkt, msg);
}

void zmq::amqp_marshaller_t::put_field_table (
    unsigned char *args, size_t args_size, size_t &offset,
    const i_amqp::field_table_t &table_)
{
    //  Skip field table size (to be filled in later)
    assert (offset + sizeof (uint32_t) <= args_size);
    offset += sizeof (uint32_t);
    size_t table_size = 0;

    for (i_amqp::field_table_t::const_iterator table_it = table_.begin();
          table_it != table_.end(); table_it++ ) {

        //  Put field name
        assert (offset + sizeof (uint8_t) + table_it->first.size () <=
            i_amqp::frame_min_size);
        put_uint8 (args + offset, table_it->first.size ());
        offset += sizeof (uint8_t);
        memcpy (args + offset, table_it->first.c_str (),
           table_it->first.size ());
        offset += table_it->first.size ();

        //  Put field type
        assert (offset + sizeof (uint8_t) <= args_size);
        put_uint8 (args + offset, 'S');
        offset += sizeof (uint8_t);

        //  Put field value
        assert (offset + sizeof (uint32_t) + table_it->second.size () <=
            i_amqp::frame_min_size);
        put_uint32 (args + offset, table_it->second.size ());
        offset += sizeof (uint32_t);
        memcpy (args + offset, table_it->second.c_str (),
            table_it->second.size ());
        offset += table_it->second.size ();

        //  Adjust actual table size
        table_size += (sizeof (uint8_t) + table_it->first.size () +
            sizeof (uint8_t) + sizeof (uint32_t) +
            table_it->second.size ());
    }

    //  Fill in the table size
    put_uint32 (args + offset - table_size - sizeof (uint32_t), table_size);
}

void ssh2channel_send_exit_status(SshChannel *sc, int status)
{
    struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
    struct ssh2_connection_state *s = c->connlayer;

    PktOut *pktout = ssh2_chanreq_init(c, "exit-status", NULL, NULL);
    put_uint32(pktout, status);

    pq_push(s->ppl.out_pq, pktout);
}

void rsa_ssh1_public_blob(BinarySink *bs, RSAKey *key,
                          RsaSsh1Order order)
{
    put_uint32(bs, mp_get_nbits(key->modulus));
    if (order == RSA_SSH1_EXPONENT_FIRST) {
        put_mp_ssh1(bs, key->exponent);
        put_mp_ssh1(bs, key->modulus);
    } else {
        put_mp_ssh1(bs, key->modulus);
        put_mp_ssh1(bs, key->exponent);
    }
}

/*
 * send Notification payload (for ISAKMP SA) in Informational exchange
 */
int
isakmp_info_send_n1(struct ph1handle *iph1, int type, rc_vchar_t *data)
{
	rc_vchar_t *payload = NULL;
	int tlen;
	int error = 0;
	struct isakmp_pl_n *n;
	int spisiz;

	/*
	 * note on SPI size: which description is correct?  I have chosen
	 * this to be 0.
	 *
	 * RFC2408 3.1, 2nd paragraph says: ISAKMP SA is identified by
	 * Initiator/Responder cookie and SPI has no meaning, SPI size = 0.
	 * RFC2408 3.1, first paragraph on page 40: ISAKMP SA is identified
	 * by cookie and SPI has no meaning, 0 <= SPI size <= 16.
	 * RFC2407 4.6.3.3, INITIAL-CONTACT is required to set to 16.
	 */
	if (type == ISAKMP_NTYPE_INITIAL_CONTACT)
		spisiz = sizeof(isakmp_index_t);
	else
		spisiz = 0;

	tlen = sizeof(*n) + spisiz;
	if (data)
		tlen += data->l;
	payload = rc_vmalloc(tlen);
	if (payload == NULL) { 
		plog(PLOG_INTERR, PLOGLOC, NULL,
			"failed to get buffer to send.\n");
		return errno;
	}

	n = (struct isakmp_pl_n *)payload->v;
	n->h.np = ISAKMP_NPTYPE_NONE;
	put_uint16(&n->h.len, tlen);
	put_uint32(&n->doi, ikev1_doitype(iph1->rmconf));
	n->proto_id = IPSECDOI_PROTO_ISAKMP; /* XXX to be configurable ? */
	n->spi_size = spisiz;
	put_uint16(&n->type, type);
	if (spisiz)
		memcpy(n + 1, &iph1->index, sizeof(isakmp_index_t));
	if (data)
		memcpy((caddr_t)(n + 1) + spisiz, data->v, data->l);

	error = isakmp_info_send_common(iph1, payload, ISAKMP_NPTYPE_N, iph1->flags);
	rc_vfree(payload);

	return error;
}

int zmq::gssapi_mechanism_base_t::encode_message (msg_t *msg_)
{
    // Wrap the token value
    int state;
    gss_buffer_desc plaintext;
    gss_buffer_desc wrapped;

    uint8_t flags = 0;
    if (msg_->flags () & msg_t::more)
        flags |= 0x01;
    if (msg_->flags () & msg_t::command)
        flags |= 0x02;

    uint8_t *plaintext_buffer = static_cast <uint8_t *>(malloc(msg_->size ()+1));
    plaintext_buffer[0] = flags;
    memcpy (plaintext_buffer+1, msg_->data(), msg_->size());

    plaintext.value = plaintext_buffer;
    plaintext.length = msg_->size ()+1;

    maj_stat = gss_wrap(&min_stat, context, 1, GSS_C_QOP_DEFAULT,
                        &plaintext, &state, &wrapped);

    zmq_assert (maj_stat == GSS_S_COMPLETE);
    zmq_assert (state);

    // Re-initialize msg_ for wrapped text
    int rc = msg_->close ();
    zmq_assert (rc == 0);

    rc = msg_->init_size (8 + 4 + wrapped.length);
    zmq_assert (rc == 0);

    uint8_t *ptr = static_cast <uint8_t *> (msg_->data ());

    // Add command string
    memcpy (ptr, "\x07MESSAGE", 8);
    ptr += 8;

    // Add token length
    put_uint32 (ptr, static_cast <uint32_t> (wrapped.length));
    ptr += 4;

    // Add wrapped token value
    memcpy (ptr, wrapped.value, wrapped.length);
    ptr += wrapped.length;

    gss_release_buffer (&min_stat, &wrapped);

    return 0;
}

void ssh2channel_send_exit_signal_numeric(
    SshChannel *sc, int signum, bool core_dumped, ptrlen msg)
{
    struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
    struct ssh2_connection_state *s = c->connlayer;

    PktOut *pktout = ssh2_chanreq_init(c, "exit-signal", NULL, NULL);
    put_uint32(pktout, signum);
    put_bool(pktout, core_dumped);
    put_stringpl(pktout, msg);
    put_stringz(pktout, "");           /* language tag */

    pq_push(s->ppl.out_pq, pktout);
}