static void afl_enc_pkt_from_file(fko_srv_options_t *opts)
{
FILE *fp = NULL;
fko_ctx_t decrypt_ctx = NULL;
unsigned char enc_spa_pkt[AFL_MAX_PKT_SIZE] = {0}, rc;
int res = 0, es = EXIT_SUCCESS, enc_msg_len;
char dump_buf[AFL_DUMP_CTX_SIZE];
fp = fopen(opts->config[CONF_AFL_PKT_FILE], "rb");
if(fp != NULL)
{
enc_msg_len = 0;
while(fread(&rc, 1, 1, fp))
{
enc_spa_pkt[enc_msg_len] = rc;
enc_msg_len++;
if(enc_msg_len == AFL_MAX_PKT_SIZE-1)
break;
}
fclose(fp);
fko_new(&decrypt_ctx);
res = fko_afl_set_spa_data(decrypt_ctx, (const char *)enc_spa_pkt,
enc_msg_len);
if(res == FKO_SUCCESS)
res = fko_decrypt_spa_data(decrypt_ctx, "fwknoptest",
strlen("fwknoptest"));
if(res == FKO_SUCCESS)
res = dump_ctx_to_buffer(decrypt_ctx, dump_buf, sizeof(dump_buf));
if(res == FKO_SUCCESS)
log_msg(LOG_INFO, "%s", dump_buf);
else
log_msg(LOG_ERR, "Error (%d): %s", res, fko_errstr(res));
fko_destroy(decrypt_ctx);
if(res == FKO_SUCCESS)
{
log_msg(LOG_INFO, "SPA packet decode: %s", fko_errstr(res));
es = EXIT_SUCCESS;
}
else
{
log_msg(LOG_ERR, "Could not decode SPA packet: %s", fko_errstr(res));
es = EXIT_FAILURE;
}
}
else
log_msg(LOG_ERR, "Could not acquire SPA packet from file: %s.",
opts->config[CONF_AFL_PKT_FILE]);
clean_exit(opts, NO_FW_CLEANUP, es);
}
static void afl_pkt_from_stdin(fko_srv_options_t *opts)
{
FILE *fp = NULL;
fko_ctx_t decode_ctx = NULL;
unsigned char spa_pkt[AFL_MAX_PKT_SIZE] = {0};
int res = 0, es = EXIT_SUCCESS;
char dump_buf[AFL_DUMP_CTX_SIZE];
fp = fdopen(STDIN_FILENO, "r");
if(fp != NULL)
{
if(fgets((char *)spa_pkt, AFL_MAX_PKT_SIZE, fp) == NULL)
{
fclose(fp);
clean_exit(opts, NO_FW_CLEANUP, EXIT_FAILURE);
}
fclose(fp);
fko_new(&decode_ctx);
res = fko_set_encoded_data(decode_ctx, (char *) spa_pkt,
strlen((char *)spa_pkt), 0, FKO_DIGEST_SHA256);
if(res == FKO_SUCCESS)
res = fko_set_spa_data(decode_ctx, (const char *) spa_pkt);
if(res == FKO_SUCCESS)
res = fko_decode_spa_data(decode_ctx);
if(res == FKO_SUCCESS)
res = dump_ctx_to_buffer(decode_ctx, dump_buf, sizeof(dump_buf));
if(res == FKO_SUCCESS)
log_msg(LOG_INFO, "%s", dump_buf);
fko_destroy(decode_ctx);
if(res == FKO_SUCCESS)
{
log_msg(LOG_INFO, "SPA packet decode: %s", fko_errstr(res));
es = EXIT_SUCCESS;
}
else
{
log_msg(LOG_ERR, "Could not decode SPA packet: %s", fko_errstr(res));
es = EXIT_FAILURE;
}
}
else
log_msg(LOG_ERR, "Could not acquire SPA packet from stdin.");
clean_exit(opts, NO_FW_CLEANUP, es);
}
/* Process the SPA packet data
*/
void
incoming_spa(fko_srv_options_t *opts)
{
/* Always a good idea to initialize ctx to null if it will be used
* repeatedly (especially when using fko_new_with_data()).
*/
fko_ctx_t ctx = NULL;
char *spa_ip_demark, *raw_digest = NULL;
int res, enc_type, stanza_num=0;
int added_replay_digest = 0;
int is_err, cmd_exec_success = 0, attempted_decrypt = 0;
int conf_pkt_age = 0;
char dump_buf[CTX_DUMP_BUFSIZE];
spa_pkt_info_t *spa_pkt = &(opts->spa_pkt);
/* This will hold our pertinent SPA data.
*/
spa_data_t spadat;
/* Loop through all access stanzas looking for a match
*/
acc_stanza_t *acc = opts->acc_stanzas;
inet_ntop(AF_INET, &(spa_pkt->packet_src_ip),
spadat.pkt_source_ip, sizeof(spadat.pkt_source_ip));
inet_ntop(AF_INET, &(spa_pkt->packet_dst_ip),
spadat.pkt_destination_ip, sizeof(spadat.pkt_destination_ip));
/* At this point, we want to validate and (if needed) preprocess the
* SPA data and/or to be reasonably sure we have a SPA packet (i.e
* try to eliminate obvious non-spa packets).
*/
if(!precheck_pkt(opts, spa_pkt, &spadat, &raw_digest))
return;
if(strncasecmp(opts->config[CONF_ENABLE_SPA_PACKET_AGING], "Y", 1) == 0)
{
conf_pkt_age = strtol_wrapper(opts->config[CONF_MAX_SPA_PACKET_AGE],
0, RCHK_MAX_SPA_PACKET_AGE, NO_EXIT_UPON_ERR, &is_err);
if(is_err != FKO_SUCCESS)
{
log_msg(LOG_ERR, "[*] [%s] invalid MAX_SPA_PACKET_AGE", spadat.pkt_source_ip);
return;
}
}
/* Now that we know there is a matching access.conf stanza and the
* incoming SPA packet is not a replay, see if we should grant any
* access
*/
while(acc)
{
res = FKO_SUCCESS;
cmd_exec_success = 0;
attempted_decrypt = 0;
stanza_num++;
/* Start access loop with a clean FKO context
*/
if(ctx != NULL)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_WARNING,
"[%s] (stanza #%d) fko_destroy() could not zero out sensitive data buffer.",
spadat.pkt_source_ip, stanza_num
);
ctx = NULL;
}
/* Check for a match for the SPA source and destination IP and the access stanza
*/
if(! src_dst_check(acc, spa_pkt, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
log_msg(LOG_INFO, "(stanza #%d) SPA Packet from IP: %s received with access source match",
stanza_num, spadat.pkt_source_ip);
log_msg(LOG_DEBUG, "SPA Packet: '%s'", spa_pkt->packet_data);
/* Make sure this access stanza has not expired
*/
if(! check_stanza_expiration(acc, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* Get encryption type and try its decoding routine first (if the key
* for that type is set)
*/
enc_type = fko_encryption_type((char *)spa_pkt->packet_data);
if(! handle_rijndael_enc(acc, spa_pkt, &spadat, &ctx,
&attempted_decrypt, &cmd_exec_success, enc_type,
stanza_num, &res))
{
acc = acc->next;
continue;
}
if(! handle_gpg_enc(acc, spa_pkt, &spadat, &ctx, &attempted_decrypt,
cmd_exec_success, enc_type, stanza_num, &res))
{
acc = acc->next;
continue;
}
if(! check_mode_ctx(&spadat, &ctx, attempted_decrypt,
enc_type, stanza_num, res))
{
acc = acc->next;
continue;
}
/* Add this SPA packet into the replay detection cache
*/
if(! add_replay_cache(opts, acc, &spadat, raw_digest,
&added_replay_digest, stanza_num, &res))
{
acc = acc->next;
continue;
}
/* At this point the SPA data is authenticated via the HMAC (if used
* for now). Next we need to see if it meets our access criteria which
* the server imposes regardless of the content of the SPA packet.
*/
log_msg(LOG_DEBUG, "[%s] (stanza #%d) SPA Decode (res=%i):",
spadat.pkt_source_ip, stanza_num, res);
res = dump_ctx_to_buffer(ctx, dump_buf, sizeof(dump_buf));
if (res == FKO_SUCCESS)
log_msg(LOG_DEBUG, "%s", dump_buf);
else
log_msg(LOG_WARNING, "Unable to dump FKO context: %s", fko_errstr(res));
/* First, if this is a GPG message, and GPG_REMOTE_ID list is not empty,
* then we need to make sure this incoming message is signer ID matches
* an entry in the list.
*/
if(! handle_gpg_sigs(acc, &spadat, &ctx, enc_type, stanza_num, &res))
{
acc = acc->next;
continue;
}
/* Populate our spa data struct for future reference.
*/
res = get_spa_data_fields(ctx, &spadat);
if(res != FKO_SUCCESS)
{
log_msg(LOG_ERR, "[%s] (stanza #%d) Unexpected error pulling SPA data from the context: %s",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
acc = acc->next;
continue;
}
/* Figure out what our timeout will be. If it is specified in the SPA
* data, then use that. If not, try the FW_ACCESS_TIMEOUT from the
* access.conf file (if there is one). Otherwise use the default.
*/
set_timeout(acc, &spadat);
/* Check packet age if so configured.
*/
if(! check_pkt_age(opts, &spadat, stanza_num, conf_pkt_age))
{
acc = acc->next;
continue;
}
/* At this point, we have enough to check the embedded (or packet source)
* IP address against the defined access rights. We start by splitting
* the spa msg source IP from the remainder of the message.
*/
spa_ip_demark = strchr(spadat.spa_message, ',');
if(spa_ip_demark == NULL)
{
log_msg(LOG_WARNING, "[%s] (stanza #%d) Error parsing SPA message string: %s",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
acc = acc->next;
continue;
}
if((spa_ip_demark-spadat.spa_message) < MIN_IPV4_STR_LEN-1
|| (spa_ip_demark-spadat.spa_message) > MAX_IPV4_STR_LEN)
{
log_msg(LOG_WARNING, "[%s] (stanza #%d) Invalid source IP in SPA message, ignoring SPA packet",
spadat.pkt_source_ip, stanza_num);
break;
}
strlcpy(spadat.spa_message_src_ip,
spadat.spa_message, (spa_ip_demark-spadat.spa_message)+1);
if(! is_valid_ipv4_addr(spadat.spa_message_src_ip))
{
log_msg(LOG_WARNING, "[%s] (stanza #%d) Invalid source IP in SPA message, ignoring SPA packet",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
break;
}
strlcpy(spadat.spa_message_remain, spa_ip_demark+1, MAX_DECRYPTED_SPA_LEN);
/* If use source IP was requested (embedded IP of 0.0.0.0), make sure it
* is allowed.
*/
if(! check_src_access(acc, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* If REQUIRE_USERNAME is set, make sure the username in this SPA data
* matches.
*/
if(! check_username(acc, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* Take action based on SPA message type.
*/
if(! check_nat_access_types(opts, acc, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* Command messages.
*/
if(spadat.message_type == FKO_COMMAND_MSG)
{
if(process_cmd_msg(opts, acc, &spadat, stanza_num, &res))
{
/* we processed the command on a matching access stanza, so we
* don't look for anything else to do with this SPA packet
*/
break;
}
else
{
acc = acc->next;
continue;
}
}
/* From this point forward, we have some kind of access message. So
* we first see if access is allowed by checking access against
* restrict_ports and open_ports.
*
* --DSS TODO: We should add BLACKLIST support here as well.
*/
if(! check_port_proto(acc, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* At this point, we process the SPA request and break out of the
* access stanza loop (first valid access stanza stops us looking
* for others).
*/
if(opts->test) /* no firewall changes in --test mode */
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) --test mode enabled, skipping firewall manipulation.",
spadat.pkt_source_ip, stanza_num
);
acc = acc->next;
continue;
}
else
{
process_spa_request(opts, acc, &spadat);
}
/* If we made it here, then the SPA packet was processed according
* to a matching access.conf stanza, so we're done with this packet.
*/
break;
}
if (raw_digest != NULL)
free(raw_digest);
if(ctx != NULL)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_WARNING,
"[%s] (stanza #%d) fko_destroy() could not zero out sensitive data buffer.",
spadat.pkt_source_ip, stanza_num
);
ctx = NULL;
}
return;
}
/* Process the SPA packet data
*/
void
incoming_spa(fko_srv_options_t *opts)
{
/* Always a good idea to initialize ctx to null if it will be used
* repeatedly (especially when using fko_new_with_data()).
*/
fko_ctx_t ctx = NULL;
char *spa_ip_demark, *raw_digest = NULL;
int res, enc_type, stanza_num=0;
int added_replay_digest = 0;
int cmd_exec_success = 0, attempted_decrypt = 0;
char dump_buf[CTX_DUMP_BUFSIZE];
spa_pkt_info_t *spa_pkt = &(opts->spa_pkt);
/* This will hold our pertinent SPA data.
*/
spa_data_t spadat;
/* Loop through all access stanzas looking for a match
*/
//²éÕÒËùÓеÄstanzas£¬Æ¥ÅäÏàÓ¦Ïî¡£
acc_stanza_t *acc = opts->acc_stanzas;
inet_ntop(AF_INET, &(spa_pkt->packet_src_ip),
spadat.pkt_source_ip, sizeof(spadat.pkt_source_ip)); //»ñÈ¡Êý¾Ý±¨À´Ô´µØÖ·¡£
inet_ntop(AF_INET, &(spa_pkt->packet_dst_ip),
spadat.pkt_destination_ip, sizeof(spadat.pkt_destination_ip)); //»ñÈ¡Êý¾Ý±¨Ä¿µÄµØÖ·¡£
/* At this point, we want to validate and (if needed) preprocess the
* SPA data and/or to be reasonably sure we have a SPA packet (i.e
* try to eliminate obvious non-spa packets).
*/
//ÔÚÕâÀÎÒÃÇÒªÑéÖ¤ºÍÔ¤´¦ÀíSPAÊý¾Ý£¬ÌÞ³ýÃ÷ÏÔ²»ÊÇSPAµÄÊý¾Ý°ü¡£
//ͨ¹ý±È¶ÔÕªÒª¼ì²éÊý¾ÝÍêÕûÐÔºÍÊÇ·ñÊܵ½ÖطŹ¥»÷¡£
//¼ÆËãctx->encrypted_msgµÄSHA256ÕªÒªÊý¾Ý£¬´æÔÚraw_digest¡£
if(!precheck_pkt(opts, spa_pkt, &spadat, &raw_digest))
return;
/* Now that we know there is a matching access.conf stanza and the
* incoming SPA packet is not a replay, see if we should grant any
* access
*/
while(acc)
{
res = FKO_SUCCESS;
cmd_exec_success = 0;
attempted_decrypt = 0;
stanza_num++;
/* Start access loop with a clean FKO context
*/
//¶Ôÿһ¸östanza½øÐÐÆ¥Å䣬ֱµ½Æ¥Åä³É¹¦ÎªÖ¹¡£
if(ctx != NULL)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_WARNING,
"[%s] (stanza #%d) fko_destroy() could not zero out sensitive data buffer.",
spadat.pkt_source_ip, stanza_num
);
ctx = NULL;
}
/* Check for a match for the SPA source and destination IP and the access stanza
*/
//Æ¥ÅästanzaÖеÄÔ´µØÖ·ºÍÄ¿µÄµØÖ·¡£
if(! src_dst_check(acc, spa_pkt, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
log_msg(LOG_INFO,
"(stanza #%d) SPA Packet from IP: %s received with access source match",
stanza_num, spadat.pkt_source_ip);
log_msg(LOG_DEBUG, "SPA Packet: '%s'", spa_pkt->packet_data);
/* Make sure this access stanza has not expired
*/
//È·±£Õâ¸östanzaûÓйýÆÚ¡£
if(! check_stanza_expiration(acc, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* Get encryption type and try its decoding routine first (if the key
* for that type is set)
*/
//¼ì²â´Ë¶ÎÃÜÎĵļÓÃÜÀàÐÍ¡£
enc_type = fko_encryption_type((char *)spa_pkt->packet_data);
//»¹Ô¼ÓÑÎÃÜÎÄ£¬Í¨¹ýHMACժҪУÑéÊý¾Ý°üµÄÍêÕûÐÔ£¬½âÃÜencrypted_msg¡£
if(acc->use_rijndael)
handle_rijndael_enc(acc, spa_pkt, &spadat, &ctx,
&attempted_decrypt, &cmd_exec_success, enc_type,
stanza_num, &res);
if(! handle_gpg_enc(acc, spa_pkt, &spadat, &ctx, &attempted_decrypt,
cmd_exec_success, enc_type, stanza_num, &res))
{
acc = acc->next;
continue;
}
if(! check_mode_ctx(&spadat, &ctx, attempted_decrypt,
enc_type, stanza_num, res))
{
acc = acc->next;
continue;
}
/* Add this SPA packet into the replay detection cache
*/
//¼ì²âÖطŹ¥»÷¡£
if(! add_replay_cache(opts, acc, &spadat, raw_digest,
&added_replay_digest, stanza_num, &res))
{
acc = acc->next;
continue;
}
/* At this point the SPA data is authenticated via the HMAC (if used
* for now). Next we need to see if it meets our access criteria which
* the server imposes regardless of the content of the SPA packet.
*/
log_msg(LOG_DEBUG, "[%s] (stanza #%d) SPA Decode (res=%i):",
spadat.pkt_source_ip, stanza_num, res);
res = dump_ctx_to_buffer(ctx, dump_buf, sizeof(dump_buf));
if (res == FKO_SUCCESS)
log_msg(LOG_DEBUG, "%s", dump_buf);
else
log_msg(LOG_WARNING, "Unable to dump FKO context: %s", fko_errstr(res));
/* First, if this is a GPG message, and GPG_REMOTE_ID list is not empty,
* then we need to make sure this incoming message is signer ID matches
* an entry in the list.
*/
if(! handle_gpg_sigs(acc, &spadat, &ctx, enc_type, stanza_num, &res))
{
acc = acc->next;
continue;
}
/* Populate our spa data struct for future reference.
*/
//ÏòspadatÖÐÌî³ä×ֶΡ£
res = get_spa_data_fields(ctx, &spadat);
if(res != FKO_SUCCESS)
{
log_msg(LOG_ERR,
"[%s] (stanza #%d) Unexpected error pulling SPA data from the context: %s",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
acc = acc->next;
continue;
}
/* Figure out what our timeout will be. If it is specified in the SPA
* data, then use that. If not, try the FW_ACCESS_TIMEOUT from the
* access.conf file (if there is one). Otherwise use the default.
*/
//²é¿´ÔÚSPAÖÐÓÐûÓÐÉèÖó¬Ê±×ֶΣ¬·ñÔò¾ÍÓÃaccess.confÖÐÉèÖõÄ×ֶΡ£
set_timeout(acc, &spadat);
/* Check packet age if so configured.
*/
//²é¿´Êý¾Ý°üÖеÄʱ¼ä´ÁÊÇ·ñ¹ýʱ¡£
if(! check_pkt_age(opts, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* At this point, we have enough to check the embedded (or packet source)
* IP address against the defined access rights. We start by splitting
* the spa msg source IP from the remainder of the message.
*/
spa_ip_demark = strchr(spadat.spa_message, ',');
if(spa_ip_demark == NULL)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Error parsing SPA message string: %s",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
acc = acc->next;
continue;
}
if((spa_ip_demark-spadat.spa_message) < MIN_IPV4_STR_LEN-1
|| (spa_ip_demark-spadat.spa_message) > MAX_IPV4_STR_LEN)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Invalid source IP in SPA message, ignoring SPA packet",
spadat.pkt_source_ip, stanza_num);
break;
}
strlcpy(spadat.spa_message_src_ip,
spadat.spa_message, (spa_ip_demark-spadat.spa_message)+1);
if(! is_valid_ipv4_addr(spadat.spa_message_src_ip))
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Invalid source IP in SPA message, ignoring SPA packet",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
break;
}
strlcpy(spadat.spa_message_remain, spa_ip_demark+1, MAX_DECRYPTED_SPA_LEN);
/* If use source IP was requested (embedded IP of 0.0.0.0), make sure it
* is allowed.
*/
if(! check_src_access(acc, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* If REQUIRE_USERNAME is set, make sure the username in this SPA data
* matches.
*/
//Èç¹ûREQUIRE_USERNAME ×ֶα»ÉèÖã¬È·±£Óû§ÃûÔÚSPAÖпɱ»Æ¥Åä¡£
if(! check_username(acc, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* Take action based on SPA message type.
*/
if(! check_nat_access_types(opts, acc, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* Command messages.
*/
if(acc->cmd_cycle_open != NULL)
{
if(cmd_cycle_open(opts, acc, &spadat, stanza_num, &res))
break; /* successfully processed a matching access stanza */
else
{
acc = acc->next;
continue;
}
}
else if(spadat.message_type == FKO_COMMAND_MSG)
{
if(process_cmd_msg(opts, acc, &spadat, stanza_num, &res))
{
/* we processed the command on a matching access stanza, so we
* don't look for anything else to do with this SPA packet
*/
break;
}
else
{
acc = acc->next;
continue;
}
}
/* From this point forward, we have some kind of access message. So
* we first see if access is allowed by checking access against
* restrict_ports and open_ports.
*
* --DSS TODO: We should add BLACKLIST support here as well.
*/
if(! check_port_proto(acc, &spadat, stanza_num))
{
acc = acc->next;
continue;
}
/* At this point, we process the SPA request and break out of the
* access stanza loop (first valid access stanza stops us looking
* for others).
*/
if(opts->test) /* no firewall changes in --test mode */
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) --test mode enabled, skipping firewall manipulation.",
spadat.pkt_source_ip, stanza_num
);
acc = acc->next;
continue;
}
else
{
if(acc->cmd_cycle_open != NULL)
{
//Ö´ÐÐiptablesµÄCMD¡£
if(cmd_cycle_open(opts, acc, &spadat, stanza_num, &res))
break; /* successfully processed a matching access stanza */
else
{
acc = acc->next;
continue;
}
}
else
{
process_spa_request(opts, acc, &spadat);
}
}
/* If we made it here, then the SPA packet was processed according
* to a matching access.conf stanza, so we're done with this packet.
*/
break;
}
if (raw_digest != NULL)
free(raw_digest);
if(ctx != NULL)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_WARNING,
"[%s] (stanza #%d) fko_destroy() could not zero out sensitive data buffer.",
spadat.pkt_source_ip, stanza_num
);
ctx = NULL;
}
return;
}
int
main(int argc, char **argv)
{
fko_ctx_t ctx = NULL;
fko_ctx_t ctx2 = NULL;
int res;
char *spa_data=NULL, *version=NULL;
char access_buf[MAX_LINE_LEN] = {0};
char key[MAX_KEY_LEN+1] = {0};
char hmac_key[MAX_KEY_LEN+1] = {0};
int key_len = 0, orig_key_len = 0, hmac_key_len = 0, enc_mode;
int tmp_port = 0;
char dump_buf[CTX_DUMP_BUFSIZE];
fko_cli_options_t options;
memset(&options, 0x0, sizeof(fko_cli_options_t));
/* Initialize the log module */
log_new();
/* Handle command line
*/
config_init(&options, argc, argv);
#if HAVE_LIBFIU
/* Set any fault injection points early
*/
if(! enable_fault_injections(&options))
clean_exit(ctx, &options, key, &key_len, hmac_key,
&hmac_key_len, EXIT_FAILURE);
#endif
/* Handle previous execution arguments if required
*/
if(prev_exec(&options, argc, argv) != 1)
clean_exit(ctx, &options, key, &key_len, hmac_key,
&hmac_key_len, EXIT_FAILURE);
if(options.show_last_command)
clean_exit(ctx, &options, key, &key_len, hmac_key,
&hmac_key_len, EXIT_SUCCESS);
/* Intialize the context
*/
res = fko_new(&ctx);
if(res != FKO_SUCCESS)
{
errmsg("fko_new", res);
clean_exit(ctx, &options, key, &key_len, hmac_key,
&hmac_key_len, EXIT_FAILURE);
}
/* Display version info and exit.
*/
if(options.version)
{
fko_get_version(ctx, &version);
fprintf(stdout, "fwknop client %s, FKO protocol version %s\n",
MY_VERSION, version);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_SUCCESS);
}
/* Set client timeout
*/
if(options.fw_timeout >= 0)
{
res = fko_set_spa_client_timeout(ctx, options.fw_timeout);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_spa_client_timeout", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
/* Set the SPA packet message type based on command line options
*/
res = set_message_type(ctx, &options);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_spa_message_type", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
/* Adjust the SPA timestamp if necessary
*/
if(options.time_offset_plus > 0)
{
res = fko_set_timestamp(ctx, options.time_offset_plus);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_timestamp", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
if(options.time_offset_minus > 0)
{
res = fko_set_timestamp(ctx, -options.time_offset_minus);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_timestamp", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
if(options.server_command[0] != 0x0)
{
/* Set the access message to a command that the server will
* execute
*/
snprintf(access_buf, MAX_LINE_LEN, "%s%s%s",
options.allow_ip_str, ",", options.server_command);
}
else
{
/* Resolve the client's public facing IP address if requestesd.
* if this fails, consider it fatal.
*/
if (options.resolve_ip_http_https)
{
if(options.resolve_http_only)
{
if(resolve_ip_http(&options) < 0)
{
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
else
{
/* Default to HTTPS */
if(resolve_ip_https(&options) < 0)
{
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
}
/* Set a message string by combining the allow IP and the
* port/protocol. The fwknopd server allows no port/protocol
* to be specified as well, so in this case append the string
* "none/0" to the allow IP.
*/
if(set_access_buf(ctx, &options, access_buf) != 1)
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
res = fko_set_spa_message(ctx, access_buf);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_spa_message", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
/* Set NAT access string
*/
if (options.nat_local || options.nat_access_str[0] != 0x0)
{
res = set_nat_access(ctx, &options, access_buf);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_nat_access_str", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
/* Set username
*/
if(options.spoof_user[0] != 0x0)
{
res = fko_set_username(ctx, options.spoof_user);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_username", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
/* Set up for using GPG if specified.
*/
if(options.use_gpg)
{
/* If use-gpg-agent was not specified, then remove the GPG_AGENT_INFO
* ENV variable if it exists.
*/
#ifndef WIN32
if(!options.use_gpg_agent)
unsetenv("GPG_AGENT_INFO");
#endif
res = fko_set_spa_encryption_type(ctx, FKO_ENCRYPTION_GPG);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_spa_encryption_type", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
/* Set gpg path if necessary
*/
if(strlen(options.gpg_exe) > 0)
{
res = fko_set_gpg_exe(ctx, options.gpg_exe);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_gpg_exe", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
/* If a GPG home dir was specified, set it here. Note: Setting
* this has to occur before calling any of the other GPG-related
* functions.
*/
if(strlen(options.gpg_home_dir) > 0)
{
res = fko_set_gpg_home_dir(ctx, options.gpg_home_dir);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_gpg_home_dir", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
res = fko_set_gpg_recipient(ctx, options.gpg_recipient_key);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_gpg_recipient", res);
if(IS_GPG_ERROR(res))
log_msg(LOG_VERBOSITY_ERROR, "GPG ERR: %s", fko_gpg_errstr(ctx));
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
if(strlen(options.gpg_signer_key) > 0)
{
res = fko_set_gpg_signer(ctx, options.gpg_signer_key);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_gpg_signer", res);
if(IS_GPG_ERROR(res))
log_msg(LOG_VERBOSITY_ERROR, "GPG ERR: %s", fko_gpg_errstr(ctx));
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
res = fko_set_spa_encryption_mode(ctx, FKO_ENC_MODE_ASYMMETRIC);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_spa_encryption_mode", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
if(options.encryption_mode && !options.use_gpg)
{
res = fko_set_spa_encryption_mode(ctx, options.encryption_mode);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_spa_encryption_mode", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
/* Set Digest type.
*/
if(options.digest_type)
{
res = fko_set_spa_digest_type(ctx, options.digest_type);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_spa_digest_type", res);
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
/* Acquire the necessary encryption/hmac keys
*/
if(get_keys(ctx, &options, key, &key_len, hmac_key, &hmac_key_len) != 1)
clean_exit(ctx, &options, key, &key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
orig_key_len = key_len;
if(options.encryption_mode == FKO_ENC_MODE_CBC_LEGACY_IV
&& key_len > 16)
{
log_msg(LOG_VERBOSITY_ERROR,
"WARNING: Encryption key in '-M legacy' mode must be <= 16 bytes");
log_msg(LOG_VERBOSITY_ERROR,
"long - truncating before sending SPA packet. Upgrading remote");
log_msg(LOG_VERBOSITY_ERROR,
"fwknopd is recommended.");
key_len = 16;
}
/* Finalize the context data (encrypt and encode the SPA data)
*/
res = fko_spa_data_final(ctx, key, key_len, hmac_key, hmac_key_len);
if(res != FKO_SUCCESS)
{
errmsg("fko_spa_data_final", res);
if(IS_GPG_ERROR(res))
log_msg(LOG_VERBOSITY_ERROR, "GPG ERR: %s", fko_gpg_errstr(ctx));
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
/* Display the context data.
*/
if (options.verbose || options.test)
{
res = dump_ctx_to_buffer(ctx, dump_buf, sizeof(dump_buf));
if (res == FKO_SUCCESS)
log_msg(LOG_VERBOSITY_NORMAL, "%s", dump_buf);
else
log_msg(LOG_VERBOSITY_WARNING, "Unable to dump FKO context: %s",
fko_errstr(res));
}
/* Save packet data payload if requested.
*/
if (options.save_packet_file[0] != 0x0)
write_spa_packet_data(ctx, &options);
/* SPA packet random destination port handling
*/
if (options.rand_port)
{
tmp_port = get_rand_port(ctx);
if(tmp_port < 0)
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
options.spa_dst_port = tmp_port;
}
/* If we are using one the "raw" modes (normally because
* we're going to spoof the SPA packet source IP), then select
* a random source port unless the source port is already set
*/
if ((options.spa_proto == FKO_PROTO_TCP_RAW
|| options.spa_proto == FKO_PROTO_UDP_RAW
|| options.spa_proto == FKO_PROTO_ICMP)
&& !options.spa_src_port)
{
tmp_port = get_rand_port(ctx);
if(tmp_port < 0)
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
options.spa_src_port = tmp_port;
}
res = send_spa_packet(ctx, &options);
if(res < 0)
{
log_msg(LOG_VERBOSITY_ERROR, "send_spa_packet: packet not sent.");
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
else
{
log_msg(LOG_VERBOSITY_INFO, "send_spa_packet: bytes sent: %i", res);
}
/* Run through a decode cycle in test mode (--DSS XXX: This test/decode
* portion should be moved elsewhere).
*/
if (options.test)
{
/************** Decoding now *****************/
/* Now we create a new context based on data from the first one.
*/
res = fko_get_spa_data(ctx, &spa_data);
if(res != FKO_SUCCESS)
{
errmsg("fko_get_spa_data", res);
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
/* Pull the encryption mode.
*/
res = fko_get_spa_encryption_mode(ctx, &enc_mode);
if(res != FKO_SUCCESS)
{
errmsg("fko_get_spa_encryption_mode", res);
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_VERBOSITY_ERROR,
"[*] Could not zero out sensitive data buffer.");
ctx = NULL;
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
/* If gpg-home-dir is specified, we have to defer decrypting if we
* use the fko_new_with_data() function because we need to set the
* gpg home dir after the context is created, but before we attempt
* to decrypt the data. Therefore we either pass NULL for the
* decryption key to fko_new_with_data() or use fko_new() to create
* an empty context, populate it with the encrypted data, set our
* options, then decode it.
*
* This also verifies the HMAC and truncates it if there are no
* problems.
*/
res = fko_new_with_data(&ctx2, spa_data, NULL,
0, enc_mode, hmac_key, hmac_key_len, options.hmac_type);
if(res != FKO_SUCCESS)
{
errmsg("fko_new_with_data", res);
if(fko_destroy(ctx2) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_VERBOSITY_ERROR,
"[*] Could not zero out sensitive data buffer.");
ctx2 = NULL;
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
res = fko_set_spa_encryption_mode(ctx2, enc_mode);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_spa_encryption_mode", res);
if(fko_destroy(ctx2) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_VERBOSITY_ERROR,
"[*] Could not zero out sensitive data buffer.");
ctx2 = NULL;
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
/* See if we are using gpg and if we need to set the GPG home dir.
*/
if(options.use_gpg)
{
if(strlen(options.gpg_home_dir) > 0)
{
res = fko_set_gpg_home_dir(ctx2, options.gpg_home_dir);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_gpg_home_dir", res);
if(fko_destroy(ctx2) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_VERBOSITY_ERROR,
"[*] Could not zero out sensitive data buffer.");
ctx2 = NULL;
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
}
}
/* Decrypt
*/
res = fko_decrypt_spa_data(ctx2, key, key_len);
if(res != FKO_SUCCESS)
{
errmsg("fko_decrypt_spa_data", res);
if(IS_GPG_ERROR(res)) {
/* we most likely could not decrypt the gpg-encrypted data
* because we don't have access to the private key associated
* with the public key we used for encryption. Since this is
* expected, return 0 instead of an error condition (so calling
* programs like the fwknop test suite don't interpret this as
* an unrecoverable error), but print the error string for
* debugging purposes. The test suite does run a series of
* tests that use a single key pair for encryption and
* authentication, so decryption become possible for these
* tests. */
log_msg(LOG_VERBOSITY_ERROR, "GPG ERR: %s\n%s", fko_gpg_errstr(ctx2),
"No access to recipient private key?");
}
if(fko_destroy(ctx2) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_VERBOSITY_ERROR,
"[*] Could not zero out sensitive data buffer.");
ctx2 = NULL;
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_FAILURE);
}
res = dump_ctx_to_buffer(ctx2, dump_buf, sizeof(dump_buf));
if (res == FKO_SUCCESS)
log_msg(LOG_VERBOSITY_NORMAL, "\nDump of the Decoded Data\n%s", dump_buf);
else
log_msg(LOG_VERBOSITY_WARNING, "Unable to dump FKO context: %s", fko_errstr(res));
if(fko_destroy(ctx2) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_VERBOSITY_ERROR,
"[*] Could not zero out sensitive data buffer.");
ctx2 = NULL;
}
clean_exit(ctx, &options, key, &orig_key_len,
hmac_key, &hmac_key_len, EXIT_SUCCESS);
return EXIT_SUCCESS; /* quiet down a gcc warning */
}
/* Process the SPA packet data
*/
void
incoming_spa(fko_srv_options_t *opts)
{
/* Always a good idea to initialize ctx to null if it will be used
* repeatedly (especially when using fko_new_with_data()).
*/
fko_ctx_t ctx = NULL;
char *spa_ip_demark, *gpg_id, *raw_digest = NULL;
time_t now_ts;
int res, status, ts_diff, enc_type, stanza_num=0;
int added_replay_digest = 0, pkt_data_len=0;
int is_err, cmd_exec_success = 0, attempted_decrypt = 0;
int conf_pkt_age = 0;
char dump_buf[CTX_DUMP_BUFSIZE];
spa_pkt_info_t *spa_pkt = &(opts->spa_pkt);
/* This will hold our pertinent SPA data.
*/
spa_data_t spadat;
/* Loop through all access stanzas looking for a match
*/
acc_stanza_t *acc = opts->acc_stanzas;
acc_string_list_t *gpg_id_ndx;
unsigned char is_gpg_match = 0;
inet_ntop(AF_INET, &(spa_pkt->packet_src_ip),
spadat.pkt_source_ip, sizeof(spadat.pkt_source_ip));
/* At this point, we want to validate and (if needed) preprocess the
* SPA data and/or to be reasonably sure we have a SPA packet (i.e
* try to eliminate obvious non-spa packets).
*/
pkt_data_len = spa_pkt->packet_data_len;
res = preprocess_spa_data(opts, spadat.pkt_source_ip);
if(res != FKO_SUCCESS)
{
log_msg(LOG_DEBUG, "[%s] preprocess_spa_data() returned error %i: '%s' for incoming packet.",
spadat.pkt_source_ip, res, get_errstr(res));
return;
}
if(opts->foreground == 1 && opts->verbose > 2)
{
printf("[+] candidate SPA packet payload:\n");
hex_dump(spa_pkt->packet_data, pkt_data_len);
}
if(strncasecmp(opts->config[CONF_ENABLE_SPA_PACKET_AGING], "Y", 1) == 0)
{
conf_pkt_age = strtol_wrapper(opts->config[CONF_MAX_SPA_PACKET_AGE],
0, RCHK_MAX_SPA_PACKET_AGE, NO_EXIT_UPON_ERR, &is_err);
if(is_err != FKO_SUCCESS)
{
log_msg(LOG_ERR, "[*] [%s] invalid MAX_SPA_PACKET_AGE", spadat.pkt_source_ip);
return;
}
}
if (is_src_match(opts->acc_stanzas, ntohl(spa_pkt->packet_src_ip)))
{
if(strncasecmp(opts->config[CONF_ENABLE_DIGEST_PERSISTENCE], "Y", 1) == 0)
{
/* Check for a replay attack
*/
res = get_raw_digest(&raw_digest, (char *)spa_pkt->packet_data);
if(res != FKO_SUCCESS)
{
if (raw_digest != NULL)
free(raw_digest);
return;
}
if (raw_digest == NULL)
return;
if (is_replay(opts, raw_digest) != SPA_MSG_SUCCESS)
{
free(raw_digest);
return;
}
}
}
else
{
log_msg(LOG_WARNING,
"No access data found for source IP: %s", spadat.pkt_source_ip
);
return;
}
/* Now that we know there is a matching access.conf stanza and the
* incoming SPA packet is not a replay, see if we should grant any
* access
*/
while(acc)
{
res = FKO_SUCCESS;
cmd_exec_success = 0;
attempted_decrypt = 0;
stanza_num++;
/* Start access loop with a clean FKO context
*/
if(ctx != NULL)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_WARNING,
"[%s] (stanza #%d) fko_destroy() could not zero out sensitive data buffer.",
spadat.pkt_source_ip, stanza_num, fko_errstr(res)
);
ctx = NULL;
}
/* Check for a match for the SPA source IP and the access stanza
*/
if(! compare_addr_list(acc->source_list, ntohl(spa_pkt->packet_src_ip)))
{
acc = acc->next;
continue;
}
log_msg(LOG_INFO, "(stanza #%d) SPA Packet from IP: %s received with access source match",
stanza_num, spadat.pkt_source_ip);
log_msg(LOG_DEBUG, "SPA Packet: '%s'", spa_pkt->packet_data);
/* Make sure this access stanza has not expired
*/
if(acc->access_expire_time > 0)
{
if(acc->expired)
{
acc = acc->next;
continue;
}
else
{
if(time(NULL) > acc->access_expire_time)
{
log_msg(LOG_INFO, "[%s] (stanza #%d) Access stanza has expired",
spadat.pkt_source_ip, stanza_num);
acc->expired = 1;
acc = acc->next;
continue;
}
}
}
/* Get encryption type and try its decoding routine first (if the key
* for that type is set)
*/
enc_type = fko_encryption_type((char *)spa_pkt->packet_data);
if(acc->use_rijndael)
{
if (acc->key == NULL)
{
log_msg(LOG_ERR,
"[%s] (stanza #%d) No KEY for RIJNDAEL encrypted messages",
spadat.pkt_source_ip, stanza_num
);
acc = acc->next;
continue;
}
/* Command mode messages may be quite long
*/
if(acc->enable_cmd_exec || enc_type == FKO_ENCRYPTION_RIJNDAEL)
{
res = fko_new_with_data(&ctx, (char *)spa_pkt->packet_data,
acc->key, acc->key_len, acc->encryption_mode, acc->hmac_key,
acc->hmac_key_len, acc->hmac_type);
attempted_decrypt = 1;
if(res == FKO_SUCCESS)
cmd_exec_success = 1;
}
}
if(acc->use_gpg && enc_type == FKO_ENCRYPTION_GPG && cmd_exec_success == 0)
{
/* For GPG we create the new context without decrypting on the fly
* so we can set some GPG parameters first.
*/
if(acc->gpg_decrypt_pw != NULL || acc->gpg_allow_no_pw)
{
res = fko_new_with_data(&ctx, (char *)spa_pkt->packet_data, NULL,
0, FKO_ENC_MODE_ASYMMETRIC, acc->hmac_key,
acc->hmac_key_len, acc->hmac_type);
if(res != FKO_SUCCESS)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Error creating fko context (before decryption): %s",
spadat.pkt_source_ip, stanza_num, fko_errstr(res)
);
acc = acc->next;
continue;
}
/* Set whatever GPG parameters we have.
*/
if(acc->gpg_exe != NULL)
{
res = fko_set_gpg_exe(ctx, acc->gpg_exe);
if(res != FKO_SUCCESS)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Error setting GPG path %s: %s",
spadat.pkt_source_ip, stanza_num, acc->gpg_exe,
fko_errstr(res)
);
acc = acc->next;
continue;
}
}
if(acc->gpg_home_dir != NULL)
{
res = fko_set_gpg_home_dir(ctx, acc->gpg_home_dir);
if(res != FKO_SUCCESS)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Error setting GPG keyring path to %s: %s",
spadat.pkt_source_ip, stanza_num, acc->gpg_home_dir,
fko_errstr(res)
);
acc = acc->next;
continue;
}
}
if(acc->gpg_decrypt_id != NULL)
fko_set_gpg_recipient(ctx, acc->gpg_decrypt_id);
/* If GPG_REQUIRE_SIG is set for this acc stanza, then set
* the FKO context accordingly and check the other GPG Sig-
* related parameters. This also applies when REMOTE_ID is
* set.
*/
if(acc->gpg_require_sig)
{
fko_set_gpg_signature_verify(ctx, 1);
/* Set whether or not to ignore signature verification errors.
*/
fko_set_gpg_ignore_verify_error(ctx, acc->gpg_ignore_sig_error);
}
else
{
fko_set_gpg_signature_verify(ctx, 0);
fko_set_gpg_ignore_verify_error(ctx, 1);
}
/* Now decrypt the data.
*/
res = fko_decrypt_spa_data(ctx, acc->gpg_decrypt_pw, 0);
attempted_decrypt = 1;
}
}
if(attempted_decrypt == 0)
{
log_msg(LOG_ERR,
"(stanza #%d) No stanza encryption mode match for encryption type: %i.",
stanza_num, enc_type);
acc = acc->next;
continue;
}
/* Do we have a valid FKO context? Did the SPA decrypt properly?
*/
if(res != FKO_SUCCESS)
{
log_msg(LOG_WARNING, "[%s] (stanza #%d) Error creating fko context: %s",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
if(IS_GPG_ERROR(res))
log_msg(LOG_WARNING, "[%s] (stanza #%d) - GPG ERROR: %s",
spadat.pkt_source_ip, stanza_num, fko_gpg_errstr(ctx));
acc = acc->next;
continue;
}
/* Add this SPA packet into the replay detection cache
*/
if (added_replay_digest == 0
&& strncasecmp(opts->config[CONF_ENABLE_DIGEST_PERSISTENCE], "Y", 1) == 0)
{
res = add_replay(opts, raw_digest);
if (res != SPA_MSG_SUCCESS)
{
log_msg(LOG_WARNING, "[%s] (stanza #%d) Could not add digest to replay cache",
spadat.pkt_source_ip, stanza_num);
acc = acc->next;
continue;
}
added_replay_digest = 1;
}
/* At this point, we assume the SPA data is valid. Now we need to see
* if it meets our access criteria.
*/
log_msg(LOG_DEBUG, "[%s] (stanza #%d) SPA Decode (res=%i):",
spadat.pkt_source_ip, stanza_num, res);
res = dump_ctx_to_buffer(ctx, dump_buf, sizeof(dump_buf));
if (res == FKO_SUCCESS)
log_msg(LOG_DEBUG, "%s", dump_buf);
else
log_msg(LOG_WARNING, "Unable to dump FKO context: %s", fko_errstr(res));
/* First, if this is a GPG message, and GPG_REMOTE_ID list is not empty,
* then we need to make sure this incoming message is signer ID matches
* an entry in the list.
*/
if(enc_type == FKO_ENCRYPTION_GPG && acc->gpg_require_sig)
{
res = fko_get_gpg_signature_id(ctx, &gpg_id);
if(res != FKO_SUCCESS)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Error pulling the GPG signature ID from the context: %s",
spadat.pkt_source_ip, stanza_num, fko_gpg_errstr(ctx));
acc = acc->next;
continue;
}
log_msg(LOG_INFO, "[%s] (stanza #%d) Incoming SPA data signed by '%s'.",
spadat.pkt_source_ip, stanza_num, gpg_id);
if(acc->gpg_remote_id != NULL)
{
is_gpg_match = 0;
for(gpg_id_ndx = acc->gpg_remote_id_list;
gpg_id_ndx != NULL; gpg_id_ndx=gpg_id_ndx->next)
{
res = fko_gpg_signature_id_match(ctx,
gpg_id_ndx->str, &is_gpg_match);
if(res != FKO_SUCCESS)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Error in GPG siganture comparision: %s",
spadat.pkt_source_ip, stanza_num, fko_gpg_errstr(ctx));
acc = acc->next;
continue;
}
if(is_gpg_match)
break;
}
if(! is_gpg_match)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Incoming SPA packet signed by ID: %s, but that ID is not the GPG_REMOTE_ID list.",
spadat.pkt_source_ip, stanza_num, gpg_id);
acc = acc->next;
continue;
}
}
}
/* Populate our spa data struct for future reference.
*/
res = get_spa_data_fields(ctx, &spadat);
/* Figure out what our timeout will be. If it is specified in the SPA
* data, then use that. If not, try the FW_ACCESS_TIMEOUT from the
* access.conf file (if there is one). Otherwise use the default.
*/
if(spadat.client_timeout > 0)
spadat.fw_access_timeout = spadat.client_timeout;
else if(acc->fw_access_timeout > 0)
spadat.fw_access_timeout = acc->fw_access_timeout;
else
spadat.fw_access_timeout = DEF_FW_ACCESS_TIMEOUT;
if(res != FKO_SUCCESS)
{
log_msg(LOG_ERR, "[%s] (stanza #%d) Unexpected error pulling SPA data from the context: %s",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
acc = acc->next;
continue;
}
/* Check packet age if so configured.
*/
if(strncasecmp(opts->config[CONF_ENABLE_SPA_PACKET_AGING], "Y", 1) == 0)
{
time(&now_ts);
ts_diff = abs(now_ts - spadat.timestamp);
if(ts_diff > conf_pkt_age)
{
log_msg(LOG_WARNING, "[%s] (stanza #%d) SPA data time difference is too great (%i seconds).",
spadat.pkt_source_ip, stanza_num, ts_diff);
acc = acc->next;
continue;
}
}
/* At this point, we have enough to check the embedded (or packet source)
* IP address against the defined access rights. We start by splitting
* the spa msg source IP from the remainder of the message.
*/
spa_ip_demark = strchr(spadat.spa_message, ',');
if(spa_ip_demark == NULL)
{
log_msg(LOG_WARNING, "[%s] (stanza #%d) Error parsing SPA message string: %s",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
acc = acc->next;
continue;
}
if((spa_ip_demark-spadat.spa_message) < MIN_IPV4_STR_LEN-1
|| (spa_ip_demark-spadat.spa_message) > MAX_IPV4_STR_LEN)
{
log_msg(LOG_WARNING, "[%s] (stanza #%d) Invalid source IP in SPA message, ignoring SPA packet",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
if(ctx != NULL)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_WARNING,
"[%s] (stanza #%d) fko_destroy() could not zero out sensitive data buffer.",
spadat.pkt_source_ip, stanza_num, fko_errstr(res)
);
ctx = NULL;
}
break;
}
strlcpy(spadat.spa_message_src_ip,
spadat.spa_message, (spa_ip_demark-spadat.spa_message)+1);
if(! is_valid_ipv4_addr(spadat.spa_message_src_ip))
{
log_msg(LOG_WARNING, "[%s] (stanza #%d) Invalid source IP in SPA message, ignoring SPA packet",
spadat.pkt_source_ip, stanza_num, fko_errstr(res));
if(ctx != NULL)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_WARNING,
"[%s] (stanza #%d) fko_destroy() could not zero out sensitive data buffer.",
spadat.pkt_source_ip, stanza_num, fko_errstr(res)
);
ctx = NULL;
}
break;
}
strlcpy(spadat.spa_message_remain, spa_ip_demark+1, MAX_DECRYPTED_SPA_LEN);
/* If use source IP was requested (embedded IP of 0.0.0.0), make sure it
* is allowed.
*/
if(strcmp(spadat.spa_message_src_ip, "0.0.0.0") == 0)
{
if(acc->require_source_address)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Got 0.0.0.0 when valid source IP was required.",
spadat.pkt_source_ip, stanza_num
);
acc = acc->next;
continue;
}
spadat.use_src_ip = spadat.pkt_source_ip;
}
else
spadat.use_src_ip = spadat.spa_message_src_ip;
/* If REQUIRE_USERNAME is set, make sure the username in this SPA data
* matches.
*/
if(acc->require_username != NULL)
{
if(strcmp(spadat.username, acc->require_username) != 0)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) Username in SPA data (%s) does not match required username: %s",
spadat.pkt_source_ip, stanza_num, spadat.username, acc->require_username
);
acc = acc->next;
continue;
}
}
/* Take action based on SPA message type.
*/
if(spadat.message_type == FKO_LOCAL_NAT_ACCESS_MSG
|| spadat.message_type == FKO_CLIENT_TIMEOUT_LOCAL_NAT_ACCESS_MSG
|| spadat.message_type == FKO_NAT_ACCESS_MSG
|| spadat.message_type == FKO_CLIENT_TIMEOUT_NAT_ACCESS_MSG)
{
#if FIREWALL_IPTABLES
if(strncasecmp(opts->config[CONF_ENABLE_IPT_FORWARDING], "Y", 1)!=0)
{
log_msg(LOG_WARNING,
"(stanza #%d) SPA packet from %s requested NAT access, but is not enabled",
stanza_num, spadat.pkt_source_ip
);
acc = acc->next;
continue;
}
#else
log_msg(LOG_WARNING,
"(stanza #%d) SPA packet from %s requested unsupported NAT access",
stanza_num, spadat.pkt_source_ip
);
acc = acc->next;
continue;
#endif
}
/* Command messages.
*/
if(spadat.message_type == FKO_COMMAND_MSG)
{
if(!acc->enable_cmd_exec)
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) SPA Command message are not allowed in the current configuration.",
spadat.pkt_source_ip, stanza_num
);
acc = acc->next;
continue;
}
else
{
log_msg(LOG_INFO,
"[%s] (stanza #%d) Processing SPA Command message: command='%s'.",
spadat.pkt_source_ip, stanza_num, spadat.spa_message_remain
);
/* Do we need to become another user? If so, we call
* run_extcmd_as and pass the cmd_exec_uid.
*/
if(acc->cmd_exec_user != NULL && strncasecmp(acc->cmd_exec_user, "root", 4) != 0)
{
log_msg(LOG_INFO, "[%s] (stanza #%d) Setting effective user to %s (UID=%i) before running command.",
spadat.pkt_source_ip, stanza_num, acc->cmd_exec_user, acc->cmd_exec_uid);
res = run_extcmd_as(acc->cmd_exec_uid,
spadat.spa_message_remain, NULL, 0, 0);
}
else /* Just run it as we are (root that is). */
res = run_extcmd(spadat.spa_message_remain, NULL, 0, 5);
/* --DSS XXX: I have found that the status (and res for that
* matter) have been unreliable indicators of the
* actual exit status of some commands. Not sure
* why yet. For now, we will take what we get.
*/
status = WEXITSTATUS(res);
if(opts->verbose > 1)
log_msg(LOG_WARNING,
"[%s] (stanza #%d) CMD_EXEC: command returned %i",
spadat.pkt_source_ip, stanza_num, status);
if(status != 0)
res = SPA_MSG_COMMAND_ERROR;
if(ctx != NULL)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_WARNING,
"[%s] (stanza #%d) fko_destroy() could not zero out sensitive data buffer.",
spadat.pkt_source_ip, stanza_num, fko_errstr(res)
);
ctx = NULL;
}
/* we processed the command on a matching access stanza, so we
* don't look for anything else to do with this SPA packet
*/
break;
}
}
/* From this point forward, we have some kind of access message. So
* we first see if access is allowed by checking access against
* restrict_ports and open_ports.
*
* --DSS TODO: We should add BLACKLIST support here as well.
*/
if(! acc_check_port_access(acc, spadat.spa_message_remain))
{
log_msg(LOG_WARNING,
"[%s] (stanza #%d) One or more requested protocol/ports was denied per access.conf.",
spadat.pkt_source_ip, stanza_num
);
acc = acc->next;
continue;
}
/* At this point, we process the SPA request and break out of the
* access stanza loop (first valid access stanza stops us looking
* for others).
*/
process_spa_request(opts, acc, &spadat);
if(ctx != NULL)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_WARNING,
"[%s] (stanza #%d) fko_destroy() could not zero out sensitive data buffer.",
spadat.pkt_source_ip, stanza_num
);
ctx = NULL;
}
break;
}
if (raw_digest != NULL)
free(raw_digest);
if(ctx != NULL)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_WARNING,
"[%s] fko_destroy() could not zero out sensitive data buffer.",
spadat.pkt_source_ip
);
ctx = NULL;
}
return;
}