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proxy_upstream.c
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proxy_upstream.c
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/*
* UFTP - UDP based FTP with multicast
*
* Copyright (C) 2001-2015 Dennis A. Bush, Jr. bush@tcnj.edu
*
* This program 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 of the License, or
* (at your option) any later version.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*
* Additional permission under GNU GPL version 3 section 7
*
* If you modify this program, or any covered work, by linking or
* combining it with the OpenSSL project's OpenSSL library (or a
* modified version of that library), containing parts covered by the
* terms of the OpenSSL or SSLeay licenses, the copyright holder
* grants you additional permission to convey the resulting work.
* Corresponding Source for a non-source form of such a combination
* shall include the source code for the parts of OpenSSL used as well
* as that of the covered work.
*/
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#ifdef WINDOWS
#include <ws2tcpip.h>
#include "win_func.h"
#else
#include <unistd.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netdb.h>
#endif
#include "proxy.h"
#include "proxy_common.h"
#include "proxy_upstream.h"
#include "proxy_downstream.h"
/**
* Finds next open slot in the global group list.
* Returns a pointer to the open slot, or NULL if none found.
*/
struct pr_group_list_t *find_open_slot(void)
{
int i;
for (i = 0; i < MAXLIST; i++) {
if (group_list[i].group_id == 0) {
memset(&group_list[i], 0, sizeof(group_list[i]));
return &group_list[i];
}
}
return NULL;
}
/**
* Calculate the master key and do key expansion to determine the symmetric
* cypher key and IV salt, and hash key for the server
*/
int calculate_server_keys(struct pr_group_list_t *group,
const struct enc_info_he *encinfo)
{
unsigned char *seed, *prf_buf;
int explen, len, seedlen;
time_t t;
uint32_t t2;
memcpy(group->rand1, encinfo->rand1, sizeof(encinfo->rand1));
if (!get_random_bytes(group->rand2, sizeof(group->rand2))) {
glog0(group, "Failed to get random bytes for rand2");
send_upstream_abort(group, 0, "Failed to get random bytes for rand2");
return 0;
}
// Sets the first 4 bytes of rand2 to the current time
t = time(NULL);
t2 = (uint32_t)(t & 0xFFFFFFFF);
*(uint32_t *)(group->rand2) = t2;
if (group->keyextype == KEYEX_RSA) {
if (!get_random_bytes(group->premaster, MASTER_LEN)) {
glog0(group, "Failed to get random bytes for premaster");
send_upstream_abort(group, 0,
"Failed to get random bytes for premaster");
return 0;
}
group->premaster_len = MASTER_LEN;
} else {
if (!get_ECDH_key(group->server_dhkey.ec, group->proxy_dhkey.ec,
group->premaster, &group->premaster_len)) {
glog0(group, "Failed to calculate ECDH key");
send_upstream_abort(group, 0, "Failed to calculate ECDH key");
return 0;
}
}
get_key_info(group->keytype, &group->keylen, &group->ivlen);
group->hmaclen = get_hash_len(group->hashtype);
explen = group->keylen + SALT_LEN + group->hmaclen;
seedlen = RAND_LEN * 2;
seed = safe_calloc(seedlen, 1);
prf_buf = safe_calloc(MASTER_LEN + explen + group->hmaclen, 1);
memcpy(seed, group->rand1, sizeof(group->rand1));
memcpy(seed + sizeof(group->rand1), group->rand2, sizeof(group->rand2));
PRF(group->hashtype, MASTER_LEN, group->premaster, group->premaster_len,
"master secret", seed, seedlen, prf_buf, &len);
memcpy(group->master,prf_buf, sizeof(group->master));
PRF(group->hashtype, explen, group->master, sizeof(group->master),
"key expansion", seed, seedlen, prf_buf, &len);
memcpy(group->hmackey, prf_buf, group->hmaclen);
memcpy(group->key, prf_buf + group->hmaclen, group->keylen);
memcpy(group->salt, prf_buf + group->hmaclen + group->keylen, SALT_LEN);
free(seed);
free(prf_buf);
return 1;
}
/**
* Read encryption related fields from an ANNOUNCE
*/
int read_announce_encryption(struct pr_group_list_t *group,
struct enc_info_he *encinfo,
const unsigned char *packet, int packetlen)
{
int keyextype, sigtype, keytype, i;
unsigned char *keys;
keys = (unsigned char *)encinfo + sizeof(struct enc_info_he);
// Sanity check the selected encryption parameters
if (!cipher_supported(encinfo->keytype)) {
glog1(group, "Keytype invalid or not supported here");
send_upstream_abort(group, 0, "Keytype invalid or not supported here");
return 0;
}
if (!hash_supported(encinfo->hashtype)) {
glog1(group, "Hashtype invalid or not supported here");
send_upstream_abort(group, 0, "Hashtype invalid or not supported here");
return 0;
}
keyextype = (encinfo->keyextype_sigtype & 0xF0) >> 4;
sigtype = encinfo->keyextype_sigtype & 0x0F;
if (((sigtype != SIG_HMAC) && (sigtype != SIG_KEYEX) &&
(sigtype != SIG_AUTHENC)) ||
((sigtype == SIG_AUTHENC) && (!is_auth_enc(encinfo->keytype)))) {
glog1(group, "Invalid sigtype specified");
send_upstream_abort(group, 0, "Invalid sigtype specified");
return 0;
}
if ((keyextype != KEYEX_RSA) && (keyextype != KEYEX_ECDH_RSA) &&
(keyextype != KEYEX_ECDH_ECDSA)) {
glog1(group, "Invalid keyextype specified");
send_upstream_abort(group, 0, "Invalid keyextype specified");
return 0;
}
group->keyextype = keyextype;
group->keytype = encinfo->keytype;
group->hashtype = encinfo->hashtype;
group->sigtype = sigtype;
group->client_auth = ((encinfo->flags & FLAG_CLIENT_AUTH) != 0);
if (!verify_fingerprint(server_fp, server_fp_count, keys,
ntohs(encinfo->keylen), group, group->src_id)) {
glog1(group, "Failed to verify server key fingerprint");
send_upstream_abort(group,0, "Failed to verify server key fingerprint");
return 0;
}
if ((group->keyextype == KEYEX_RSA) ||
(group->keyextype == KEYEX_ECDH_RSA)) {
keytype = KEYBLOB_RSA;
} else {
keytype = KEYBLOB_EC;
}
// Load server key and select a matching client key
if (keytype == KEYBLOB_RSA) {
if (!import_RSA_key(&group->server_pubkey.rsa, keys,
ntohs(encinfo->keylen))) {
glog1(group, "Failed to load server public key");
send_upstream_abort(group, 0, "Failed to load server public key");
return 0;
}
group->server_pubkeylen = RSA_keylen(group->server_pubkey.rsa);
for (i = 0; i < key_count; i++) {
if ((privkey_type[i] == KEYBLOB_RSA) &&
(group->server_pubkeylen) == RSA_keylen(privkey[i].rsa)) {
group->proxy_privkey = privkey[i];
group->proxy_privkeylen = RSA_keylen(privkey[i].rsa);
break;
}
}
} else {
if (!import_EC_key(&group->server_pubkey.ec, keys,
ntohs(encinfo->keylen), 0)) {
glog1(group, "Failed to load server public key");
send_upstream_abort(group, 0, "Failed to load server public key");
return 0;
}
group->server_pubkeylen = ECDSA_siglen(group->server_pubkey.ec);
for (i = 0; i < key_count; i++) {
if ((privkey_type[i] == KEYBLOB_EC) &&
(get_EC_curve(group->server_pubkey.ec) ==
get_EC_curve(privkey[i].ec))) {
group->proxy_privkey = privkey[i];
group->proxy_privkeylen = ECDSA_siglen(privkey[i].ec);
break;
}
}
}
if (!group->proxy_privkey.key) {
glog1(group, "No proxy key compatible with server key");
send_upstream_abort(group,0, "No proxy key compatible with server key");
return 0;
}
if ((group->keyextype == KEYEX_ECDH_ECDSA) ||
(group->keyextype == KEYEX_ECDH_RSA)) {
unsigned char *sigcopy;
int siglen;
unsigned char *dhblob = keys + ntohs(encinfo->keylen);
unsigned char *sig = dhblob + ntohs(encinfo->dhlen);
if (!import_EC_key(&group->server_dhkey.ec, dhblob,
ntohs(encinfo->dhlen), 1)) {
glog1(group, "Failed to load server public ECDH key");
send_upstream_abort(group, 0,
"Failed to load server public ECDH key");
return 0;
}
if (proxy_type == RESPONSE_PROXY) {
if (get_EC_curve(group->server_pubkey.ec) ==
get_EC_curve(dhkey.ec)) {
group->proxy_dhkey = dhkey;
} else {
glog1(group, "Proxy ECDH key not compatible with server key");
send_upstream_abort(group, 0,
"Proxy ECDH key not compatible with server key");
return 0;
}
} else {
group->proxy_dhkey.ec =
gen_EC_key(get_EC_curve(group->server_dhkey.ec), 1, NULL);
if (!group->proxy_dhkey.key) {
glog0(group, "Failed to generate proxy ECDH key");
send_upstream_abort(group, 0,
"Failed to generate proxy ECDH key");
return 0;
}
}
siglen = ntohs(encinfo->siglen);
sigcopy = safe_calloc(siglen, 1);
memcpy(sigcopy, sig, siglen);
memset(sig, 0, siglen);
if (keytype == KEYBLOB_RSA) {
if (!verify_RSA_sig(group->server_pubkey.rsa, group->hashtype,
packet, packetlen, sigcopy, siglen)) {
glog1(group, "Signature verification failed");
send_upstream_abort(group, 0, "Signature verification failed");
free(sigcopy);
return 0;
}
} else {
if (!verify_ECDSA_sig(group->server_pubkey.ec, group->hashtype,
packet, packetlen, sigcopy, siglen)) {
glog1(group, "Signature verification failed");
send_upstream_abort(group, 0, "Signature verification failed");
free(sigcopy);
return 0;
}
}
free(sigcopy);
}
// Calculate keys
if (!calculate_server_keys(group, encinfo)) {
return 0;
}
return 1;
}
/**
* Read in the contents of an ANNOUNCE.
*/
int read_announce(struct pr_group_list_t *group, unsigned char *packet,
const union sockaddr_u *src, int packetlen)
{
struct uftp_h *header;
struct announce_h *announce;
struct enc_info_he *encinfo;
uint8_t *publicmcast, *privatemcast;
uint8_t *he;
unsigned int iplen, extlen;
header = (struct uftp_h *)packet;
announce = (struct announce_h *)(packet + sizeof(struct uftp_h));
encinfo = NULL;
group->version = header->version;
group->group_id = ntohl(header->group_id);
group->group_inst = header->group_inst;
group->up_addr = *src;
group->src_id = header->src_id;
group->grtt = unquantize_grtt(header->grtt);
group->robust = announce->robust;
group->cc_type = announce->cc_type;
group->gsize = unquantize_gsize(header->gsize);
group->blocksize = ntohs(announce->blocksize);
iplen = ((announce->flags & FLAG_IPV6) != 0) ?
sizeof(struct in6_addr) : sizeof(struct in_addr);
publicmcast = ((uint8_t *)announce) + sizeof(struct announce_h);
privatemcast = publicmcast + iplen;
if ((announce->flags & FLAG_IPV6) != 0) {
group->publicmcast.sin6.sin6_family = AF_INET6;
group->privatemcast.sin6.sin6_family = AF_INET6;
memcpy(&group->publicmcast.sin6.sin6_addr.s6_addr, publicmcast, iplen);
memcpy(&group->privatemcast.sin6.sin6_addr.s6_addr, privatemcast,iplen);
group->publicmcast.sin6.sin6_port = htons(out_port);
group->privatemcast.sin6.sin6_port = htons(out_port);
} else {
group->publicmcast.sin.sin_family = AF_INET;
group->privatemcast.sin.sin_family = AF_INET;
memcpy(&group->publicmcast.sin.sin_addr.s_addr, publicmcast, iplen);
memcpy(&group->privatemcast.sin.sin_addr.s_addr, privatemcast, iplen);
group->publicmcast.sin.sin_port = htons(out_port);
group->privatemcast.sin.sin_port = htons(out_port);
}
if ((announce->hlen * 4U) < sizeof(struct announce_h) + (2U * iplen)) {
glog1(group, "Rejecting ANNOUNCE from %08X: invalid header size",
ntohl(group->src_id));
send_upstream_abort(group, 0, "Invalid header size");
return 0;
}
if ((announce->hlen * 4U) > sizeof(struct announce_h) + (2U * iplen)) {
he = (uint8_t *)announce + sizeof(struct announce_h) + (2U * iplen);
if (*he == EXT_ENC_INFO) {
encinfo = (struct enc_info_he *)he;
extlen = encinfo->extlen * 4U;
if ((extlen > ((announce->hlen * 4U) -
sizeof(struct announce_h))) ||
(extlen < sizeof(struct enc_info_he)) ||
(extlen != (sizeof(struct enc_info_he) +
ntohs(encinfo->keylen) + ntohs(encinfo->dhlen) +
ntohs(encinfo->siglen)))) {
glog1(group, "Rejecting ANNOUNCE from %08X: "
"invalid extension size", ntohl(group->src_id));
send_upstream_abort(group, 0, "Invalid extension size");
return 0;
}
}
}
if ((encinfo != NULL) && (proxy_type != SERVER_PROXY)) {
if (!read_announce_encryption(group, encinfo, packet, packetlen)) {
return 0;
}
} else {
group->keyextype = KEYEX_NONE;
group->keytype = KEY_NONE;
group->hashtype = HASH_NONE;
group->sigtype = SIG_NONE;
group->client_auth = 0;
}
gettimeofday(&group->phase_expire_time, NULL);
if (group->robust * group->grtt < 1.0) {
add_timeval_d(&group->phase_expire_time, 1.0);
} else {
add_timeval_d(&group->phase_expire_time, group->robust * group->grtt);
}
// Size of data packet, used in transmission speed calculations
group->datapacketsize = group->blocksize + sizeof(struct fileseg_h);
if (group->cc_type == CC_TFMCC) {
group->datapacketsize += sizeof(struct tfmcc_data_info_he);
}
if (group->keytype != KEY_NONE) {
group->datapacketsize += ((group->sigtype == SIG_KEYEX) ?
group->server_pubkeylen : (group->sigtype == SIG_HMAC) ?
group->hmaclen : 0) + KEYBLSIZE + sizeof(struct encrypted_h);
}
// 8 = UDP size, 20 = IPv4 size, 40 = IPv6 size
if ((announce->flags & FLAG_IPV6) != 0) {
group->datapacketsize += sizeof(struct uftp_h) + 8 + 40;
} else {
group->datapacketsize += sizeof(struct uftp_h) + 8 + 20;
}
return 1;
}
/**
* Inserts the proxy's public keys into an ANNOUNCE
* Returns 1 on success, 0 on fail
*/
int insert_pubkey_in_announce(struct pr_group_list_t *group,
unsigned char *packet, int packetlen)
{
struct announce_h *announce;
struct enc_info_he *encinfo;
unsigned char *keyblob, *dhkeyblob;
uint16_t bloblen;
unsigned int iplen;
announce = (struct announce_h *)(packet + sizeof(struct uftp_h));
iplen = ((announce->flags & FLAG_IPV6) != 0) ? 16 : 4;
encinfo = (struct enc_info_he *)
((uint8_t *)announce + sizeof(struct announce_h) + (2U * iplen));
keyblob = ((unsigned char *)encinfo + sizeof(struct enc_info_he));
dhkeyblob = keyblob + ntohs(encinfo->keylen);
if ((group->keytype != KEY_NONE) && (proxy_type == CLIENT_PROXY)) {
// Plug in proxy's public key for server's
if ((group->keyextype == KEYEX_RSA) ||
(group->keyextype == KEYEX_ECDH_RSA)) {
if (!export_RSA_key(group->proxy_privkey.rsa, keyblob, &bloblen)) {
glog0(group, "Error exporting proxy public key");
return 0;
}
} else {
if (!export_EC_key(group->proxy_privkey.ec, keyblob, &bloblen)) {
glog0(group, "Error exporting proxy public key");
return 0;
}
}
if (bloblen != ntohs(encinfo->keylen)) {
glog0(group, "Incorrect exported proxy key size");
return 0;
}
if ((group->keyextype == KEYEX_ECDH_ECDSA) ||
(group->keyextype == KEYEX_ECDH_RSA)) {
if (!export_EC_key(group->proxy_dhkey.ec, dhkeyblob, &bloblen)) {
glog0(group, "Error exporting proxy ECDH public key");
return 0;
}
if (bloblen != ntohs(encinfo->dhlen)) {
glog0(group, "Incorrect exported proxy ECDH key size");
return 0;
}
}
}
return 1;
}
/**
* Handles an incoming ANNOUNCE message from a server.
* Sets up encryption if specified and forwards message.
*/
void handle_announce(struct pr_group_list_t *group,
const union sockaddr_u *src, unsigned char *packet,
unsigned packetlen)
{
struct uftp_h *header;
struct announce_h *announce;
char pubname[INET6_ADDRSTRLEN], privname[INET6_ADDRSTRLEN];
int rval;
header = (struct uftp_h *)packet;
announce = (struct announce_h *)(packet + sizeof(struct uftp_h));
if ((packetlen < sizeof(struct uftp_h) + (announce->hlen * 4)) ||
((announce->hlen * 4) < sizeof(struct announce_h))) {
glog1(group, "Rejecting ANNOUNCE from %08X: "
"invalid message size", ntohl(header->src_id));
return;
}
if (group == NULL) {
if ((group = find_open_slot()) == NULL ) {
log1(ntohl(header->group_id), group->group_inst, 0,
"Error: maximum number of incoming files exceeded: %d\n",
MAXLIST);
return;
}
if (!read_announce(group, packet, src, packetlen)) {
return;
}
if ((rval = getnameinfo((struct sockaddr *)&group->publicmcast,
family_len(group->publicmcast), pubname, sizeof(pubname),
NULL, 0, NI_NUMERICHOST)) != 0) {
glog1(group, "getnameinfo failed: %s", gai_strerror(rval));
}
if ((rval = getnameinfo((struct sockaddr *)&group->privatemcast,
family_len(group->privatemcast), privname, sizeof(privname),
NULL, 0, NI_NUMERICHOST)) != 0) {
glog1(group, "getnameinfo failed: %s", gai_strerror(rval));
}
glog2(group, "Received request from %08X", ntohl(group->src_id));
glog2(group, "Using public multicast address %s", pubname);
glog2(group, "Using private multicast address %s",privname);
if (!addr_blank(&group->privatemcast) && (proxy_type != CLIENT_PROXY)) {
if (server_fp_count) {
if (!is_multicast(&group->privatemcast, 1)) {
glog1(group,"Invalid source specific multicast address: %s",
privname);
send_upstream_abort(group, 0,
"Invalid source specific multicast address");
return;
}
} else {
if (!is_multicast(&group->privatemcast, 0)) {
glog1(group, "Invalid multicast address: %s", privname);
send_upstream_abort(group, 0, "Invalid multicast address");
return;
}
}
if (!other_mcast_users(group)) {
if (!multicast_join(listener, group->group_id,
&group->privatemcast, m_interface, interface_count,
server_fp, server_fp_count)) {
send_upstream_abort(group,0,"Error joining multicast group");
return;
}
}
group->multi_join = 1;
}
group->phase = PR_PHASE_REGISTERED;
}
if (insert_pubkey_in_announce(group, packet, packetlen)) {
forward_message(group, src, packet, packetlen);
}
}
/**
* Handles in incoming REG_CONF from a server when encryption is enabled.
* Upon receiving this message, mark all clients listed as having received.
* If we got a KEYINFO from the server, send a KEYINFO to all marked clients.
*/
void handle_regconf(struct pr_group_list_t *group, const unsigned char *message,
unsigned meslen)
{
const struct regconf_h *regconf;
const uint32_t *addrlist;
int hostidx, idx, addrcnt;
struct pr_destinfo_t *dest;
regconf = (const struct regconf_h *)message;
addrlist = (const uint32_t *)(message + (regconf->hlen * 4));
addrcnt = (meslen - (regconf->hlen * 4)) / 4;
if ((meslen < (regconf->hlen * 4U)) ||
((regconf->hlen * 4U) < sizeof(struct regconf_h))) {
glog1(group, "Rejecting REG_CONF from server: invalid message size");
return;
}
glog2(group, "Received REG_CONF");
for (idx = 0; idx < addrcnt; idx++) {
hostidx = find_client(group, addrlist[idx]);
if (hostidx != -1) {
dest = &group->destinfo[hostidx];
glog2(group, " for %s", dest->name);
if (dest->state != PR_CLIENT_READY) {
dest->state = PR_CLIENT_CONF;
}
}
}
if (group->phase == PR_PHASE_READY) {
send_keyinfo(group, addrlist, addrcnt);
}
set_timeout(group, 0, 0);
}
/**
* Handles an incoming KEYINFO message from a server.
* Expected in response to a REGISTER when encryption is enabled. The proxy
* itself should be specified, not any clients behind it.
*/
void handle_keyinfo(struct pr_group_list_t *group, unsigned char *message,
unsigned meslen, uint32_t src_id)
{
struct keyinfo_h *keyinfo_hdr;
struct destkey *keylist;
unsigned explen, declen;
int i, keyidx, len, keycount, unauth_keytype, unauth_keylen, unauth_ivlen;
uint8_t decgroupmaster[MASTER_LEN], *prf_buf, *iv;
uint64_t ivctr;
keyinfo_hdr = (struct keyinfo_h *)message;
keylist = (struct destkey *)(message + (keyinfo_hdr->hlen * 4));
keycount = (meslen - (keyinfo_hdr->hlen * 4)) / sizeof(struct destkey);
if ((meslen < (keyinfo_hdr->hlen * 4U)) ||
((keyinfo_hdr->hlen * 4U) < sizeof(struct keyinfo_h))) {
glog1(group, "Rejecting KEYINFO from server: invalid message size");
return;
}
if (group->keytype == KEY_NONE) {
glog1(group, "Rejecting KEYINFO from server: encryption not enabled");
return;
}
for (i = 0, keyidx = -1; (i < keycount) && (keyidx == -1); i++) {
if (uid == keylist[i].dest_id) {
keyidx = i;
break;
}
}
// Don't use a cipher in an authentication mode to decrypt the group master
unauth_keytype = unauth_key(group->keytype);
get_key_info(unauth_keytype, &unauth_keylen, &unauth_ivlen);
if (keyidx != -1) {
glog2(group, "Received KEYINFO");
if (group->phase != PR_PHASE_REGISTERED) {
// We already got the KEYINFO, so no need to reprocess.
// Just resend the INFO_ACK and reset the timeout
send_keyinfo_ack(group);
return;
}
iv = safe_calloc(unauth_ivlen, 1);
ivctr = ntohl(keyinfo_hdr->iv_ctr_lo);
ivctr |= (uint64_t)ntohl(keyinfo_hdr->iv_ctr_hi) << 32;
build_iv(iv, group->salt, unauth_ivlen, uftp_htonll(ivctr), src_id);
if (!decrypt_block(unauth_keytype, iv, group->key, NULL, 0,
keylist[keyidx].groupmaster, MASTER_LEN,
decgroupmaster, &declen) ||
(declen != MASTER_LEN - 1)) {
glog1(group, "Decrypt failed for group master");
send_upstream_abort(group, 0, "Decrypt failed for group master");
free(iv);
return;
}
free(iv);
group->groupmaster[0] = group->version;
memcpy(&group->groupmaster[1], decgroupmaster, declen);
explen = group->keylen + SALT_LEN + group->hmaclen;
prf_buf = safe_calloc(explen + group->hmaclen, 1);
PRF(group->hashtype, explen, group->groupmaster,
sizeof(group->groupmaster), "key expansion",
group->rand1, sizeof(group->rand1), prf_buf, &len);
memcpy(group->grouphmackey, prf_buf, group->hmaclen);
memcpy(group->groupkey, prf_buf + group->hmaclen, group->keylen);
memcpy(group->groupsalt, prf_buf + group->hmaclen + group->keylen,
SALT_LEN);
free(prf_buf);
group->phase = PR_PHASE_READY;
// Respond to server, then send any pending REG_CONFs as KEYINFO
send_keyinfo_ack(group);
send_keyinfo(group, NULL, 0);
}
}
/**
* Sends a REGISTER to the server for all pending clients.
*/
void send_register(struct pr_group_list_t *group, int pendidx)
{
struct uftp_h *header;
struct register_h *reg;
unsigned char *buf, *keydata;
uint32_t *addrlist;
unsigned int len, meslen, destcount;
struct timeval now, send_time;
buf = safe_calloc(MAXMTU, 1);
header = (struct uftp_h *)buf;
reg = (struct register_h *)(buf + sizeof(struct uftp_h));
keydata = (unsigned char *)reg + sizeof(struct register_h);
set_uftp_header(header, REGISTER, group);
reg->func = REGISTER;
if (group->keytype != KEY_NONE) {
memcpy(reg->rand2, group->rand2, RAND_LEN);
if (group->keyextype == KEYEX_RSA) {
if (!RSA_encrypt(group->server_pubkey.rsa, group->premaster,
group->premaster_len, keydata, &len)) {
glog0(group, "Error encrypting premaster secret");
send_upstream_abort(group, 0,
"Error encrypting premaster secret");
free(buf);
return;
}
} else {
uint16_t keylen;
if (!export_EC_key(group->proxy_dhkey.ec, keydata, &keylen)) {
glog0(group, "Error exporting ECDH public key");
send_upstream_abort(group,0, "Error exporting ECDH public key");
free(buf);
return;
}
len = keylen;
}
reg->keyinfo_len = htons(len);
} else {
len = 0;
}
gettimeofday(&now, NULL);
if (cmptimestamp(now, group->pending[pendidx].rx_tstamp) <= 0) {
send_time = group->pending[pendidx].tstamp;
} else {
send_time = add_timeval(group->pending[pendidx].tstamp,
diff_timeval(now, group->pending[pendidx].rx_tstamp));
}
reg->tstamp_sec = htonl((uint32_t)send_time.tv_sec);
reg->tstamp_usec = htonl((uint32_t)send_time.tv_usec);
addrlist = (uint32_t *)(keydata + len);
reg->hlen = (sizeof(struct register_h) + len) / 4;
destcount = load_pending(group, pendidx, REGISTER, addrlist,
max_msg_dest(group, REGISTER, reg->hlen * 4));
meslen = sizeof(struct uftp_h) + (reg->hlen * 4) + (destcount * 4);
if (nb_sendto(listener, buf, meslen, 0, (struct sockaddr *)&group->up_addr,
family_len(group->up_addr)) == SOCKET_ERROR) {
gsockerror(group, "Error sending REGISTER");
} else {
glog2(group, "REGISTER sent");
}
if (group->client_auth) {
send_clientkey(group);
}
set_timeout(group, 1, 0);
free(buf);
}
/**
* Sends a CLIENT_KEY message to the server if requested.
*/
void send_clientkey(struct pr_group_list_t *group)
{
struct uftp_h *header;
struct client_key_h *client_key;
unsigned char *buf, *keyblob, *verify;
uint8_t *verifydata;
unsigned int siglen, meslen;
uint16_t bloblen;
int verifylen;
buf = safe_calloc(MAXMTU, 1);
header = (struct uftp_h *)buf;
client_key = (struct client_key_h *)(buf + sizeof(struct uftp_h));
keyblob = (unsigned char *)client_key + sizeof(struct client_key_h);
verifydata = build_verify_data(group, -1, &verifylen, 0);
if (!verifydata) {
glog0(group, "Error getting verify data");
send_upstream_abort(group, 0, "Error getting verify data");
goto end;
}
set_uftp_header(header, CLIENT_KEY, group);
client_key->func = CLIENT_KEY;
if ((group->keyextype == KEYEX_RSA) ||
(group->keyextype == KEYEX_ECDH_RSA)) {
if (!export_RSA_key(group->proxy_privkey.rsa, keyblob, &bloblen)) {
glog0(group, "Error exporting public key");
send_upstream_abort(group, 0, "Error exporting public key");
goto end;
}
verify = keyblob + bloblen;
if (!create_RSA_sig(group->proxy_privkey.rsa, group->hashtype,
verifydata, verifylen, verify, &siglen) ||
(siglen > group->proxy_privkeylen)) {
glog0(group, "Error signing verify data");
send_upstream_abort(group, 0, "Error signing verify data");
goto end;
}
} else {
if (!export_EC_key(group->proxy_privkey.ec, keyblob, &bloblen)) {
glog0(group, "Error exporting public key");
send_upstream_abort(group, 0, "Error exporting public key");
goto end;
}
verify = keyblob + bloblen;
if (!create_ECDSA_sig(group->proxy_privkey.ec, group->hashtype,
verifydata, verifylen, verify, &siglen)) {
glog0(group, "Error signing verify data");
send_upstream_abort(group, 0, "Error signing verify data");
goto end;
}
}
client_key->bloblen = htons(bloblen);
client_key->siglen = htons(siglen);
client_key->hlen = (sizeof(struct client_key_h) + bloblen + siglen) / 4;
meslen = sizeof(struct uftp_h) + (client_key->hlen * 4);
if (nb_sendto(listener, buf, meslen, 0, (struct sockaddr *)&group->up_addr,
family_len(group->up_addr)) == SOCKET_ERROR) {
gsockerror(group, "Error sending CLIENT_KEY");
} else {
glog2(group, "CLIENT_KEY sent");
}
end:
free(verifydata);
free(buf);
}
/**
* Sends an KEYINFO_ACK to the server in response to a KEYINFO
*/
void send_keyinfo_ack(struct pr_group_list_t *group)
{
unsigned char *buf, *encrypted;
struct uftp_h *header;
struct keyinfoack_h *keyinfo_ack;
unsigned char *verifydata, *verify_hash, *verify_val;
unsigned int payloadlen, hashlen;
int verifylen, len, enclen;
buf = safe_calloc(MAXMTU, 1);
header = (struct uftp_h *)buf;
keyinfo_ack = (struct keyinfoack_h *)(buf + sizeof(struct uftp_h));
set_uftp_header(header, KEYINFO_ACK, group);
keyinfo_ack->func = KEYINFO_ACK;
keyinfo_ack->hlen = sizeof(struct keyinfoack_h) / 4;
verifydata = build_verify_data(group, -1, &verifylen, 1);
if (!verifydata) {
glog0(group, "Error getting verify data");
send_upstream_abort(group, 0, "Error getting verify data");
free(buf);
return;
}
verify_hash = safe_calloc(group->hmaclen, 1);
verify_val = safe_calloc(VERIFY_LEN + group->hmaclen, 1);
hash(group->hashtype, verifydata, verifylen, verify_hash, &hashlen);
PRF(group->hashtype, VERIFY_LEN, group->groupmaster,
sizeof(group->groupmaster), "client finished",
verify_hash, hashlen, verify_val, &len);
memcpy(keyinfo_ack->verify_data, verify_val, VERIFY_LEN);
free(verifydata);
free(verify_hash);
free(verify_val);
payloadlen = sizeof(struct keyinfoack_h);
encrypted = NULL;
if (!encrypt_and_sign(buf, &encrypted, payloadlen, &enclen,
group->keytype, group->groupkey, group->groupsalt, &group->ivctr,
group->ivlen, group->hashtype, group->grouphmackey, group->hmaclen,
group->sigtype, group->keyextype, group->proxy_privkey,
group->proxy_privkeylen)) {
glog0(group, "Error encrypting KEYINFO_ACK");
free(buf);
return;
}
payloadlen = enclen + sizeof(struct uftp_h);
if (nb_sendto(listener, encrypted, payloadlen, 0,
(struct sockaddr *)&group->up_addr,
family_len(group->up_addr)) == SOCKET_ERROR) {
gsockerror(group, "Error sending KEYINFO_ACK");
} else {
glog2(group, "KEYINFO_ACK sent");
}
set_timeout(group, 0, 0);
free(encrypted);
free(buf);
}
/**
* Sends a FILEINFO_ACK to the server for all pending clients
*/
void send_fileinfo_ack(struct pr_group_list_t *group, int pendidx)
{
unsigned char *buf, *encrypted, *outpacket;
struct uftp_h *header;
struct fileinfoack_h *fileinfo_ack;
struct pr_pending_info_t *pending;
unsigned int payloadlen;
int destcount, enclen;
uint32_t *addrlist;
struct timeval now, send_time;
buf = safe_calloc(MAXMTU, 1);
pending = &group->pending[pendidx];
header = (struct uftp_h *)buf;
fileinfo_ack = (struct fileinfoack_h *)(buf + sizeof(struct uftp_h));
addrlist =(uint32_t *)((char *)fileinfo_ack + sizeof(struct fileinfoack_h));
payloadlen = sizeof(struct fileinfoack_h);
set_uftp_header(header, FILEINFO_ACK, group);
fileinfo_ack->func = FILEINFO_ACK;
fileinfo_ack->hlen = sizeof(struct fileinfoack_h) / 4;
fileinfo_ack->file_id = htons(pending->file_id);
if (pending->partial) {
fileinfo_ack->flags |= FLAG_PARTIAL;
}
gettimeofday(&now, NULL);
if (cmptimestamp(now, group->pending[pendidx].rx_tstamp) <= 0) {
send_time = group->pending[pendidx].tstamp;
} else {
send_time = add_timeval(group->pending[pendidx].tstamp,
diff_timeval(now, group->pending[pendidx].rx_tstamp));
}
fileinfo_ack->tstamp_sec = htonl((uint32_t)send_time.tv_sec);
fileinfo_ack->tstamp_usec = htonl((uint32_t)send_time.tv_usec);
destcount = load_pending(group, pendidx, FILEINFO_ACK, addrlist,
max_msg_dest(group, FILEINFO_ACK, fileinfo_ack->hlen * 4));
payloadlen += destcount * sizeof(uint32_t);
if (group->keytype != KEY_NONE) {
encrypted = NULL;
if (!encrypt_and_sign(buf, &encrypted, payloadlen, &enclen,
group->keytype, group->groupkey, group->groupsalt,&group->ivctr,
group->ivlen, group->hashtype, group->grouphmackey,
group->hmaclen, group->sigtype, group->keyextype,
group->proxy_privkey, group->proxy_privkeylen)) {
log0(group->group_id, group->group_inst, pending->file_id,
"Error encrypting FILEINFO_ACK");
free(buf);
return;
}
outpacket = encrypted;
payloadlen = enclen;
} else {
encrypted = NULL;
outpacket = buf;
}
payloadlen += sizeof(struct uftp_h);
if (nb_sendto(listener, outpacket, payloadlen, 0,
(struct sockaddr *)&group->up_addr,
family_len(group->up_addr)) == SOCKET_ERROR) {
sockerror(group->group_id, group->group_inst, pending->file_id,
"Error sending FILEINFO_ACK");
} else {
log2(group->group_id, group->group_inst, pending->file_id,
"FILEINFO_ACK sent");
}
set_timeout(group, 1, 0);
free(encrypted);
free(buf);
}
/**
* Counts the pending naks for the given group
*/
int count_naks(struct pr_group_list_t *group, int pendidx)
{
unsigned nak_count, i;
for (nak_count = 0, i = 0; i < group->blocksize * 8; i++) {
if ((group->pending[pendidx].naklist[i >> 3] & (1 << (i & 7))) != 0) {
nak_count++;
}
}
// Highly verbose debugging -- print aggregate NAKs before sending
if (log_level >= 5) {
for (i = 0; i < group->blocksize; i++) {
sclog5("%02X ", group->pending[pendidx].naklist[i]);
if (i % 25 == 24) slog5("");
}
slog5("");
}
return nak_count;
}
/**
* Sends a STATUS to the server for all pending clients.
*/
void send_status(struct pr_group_list_t *group, int pendidx)
{
unsigned char *buf, *encrypted, *outpacket;
struct uftp_h *header;
struct status_h *status;
unsigned char *sent_naks;
struct pr_pending_info_t *pending;