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fwknop/client/fwknop.c
Michael Rash 0bae1a5a1b started on 2.6.1 ChangeLog entries
2014-03-09 19:16:36 -04:00

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/**
* @file fwknop.c
*
* @brief The fwknop client.
*
* Fwknop is developed primarily by the people listed in the file 'AUTHORS'.
* Copyright (C) 2009–2014 fwknop developers and contributors. For a full
* list of contributors, see the file 'CREDITS'.
*
* License (GNU General Public License):
*
* 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 2
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
#include "fwknop.h"
#include "config_init.h"
#include "spa_comm.h"
#include "utils.h"
#include "getpasswd.h"
#include <sys/stat.h>
#include <fcntl.h>
/* prototypes
*/
static int get_keys(fko_ctx_t ctx, fko_cli_options_t *options,
char *key, int *key_len, char *hmac_key, int *hmac_key_len);
static void errmsg(const char *msg, const int err);
static int prev_exec(fko_cli_options_t *options, int argc, char **argv);
static int get_save_file(char *args_save_file);
static int show_last_command(const char * const args_save_file);
static int save_args(int argc, char **argv, const char * const args_save_file);
static int run_last_args(fko_cli_options_t *options,
const char * const args_save_file);
static int set_message_type(fko_ctx_t ctx, fko_cli_options_t *options);
static int set_nat_access(fko_ctx_t ctx, fko_cli_options_t *options,
const char * const access_buf);
static int set_access_buf(fko_ctx_t ctx, fko_cli_options_t *options,
char *access_buf);
static int get_rand_port(fko_ctx_t ctx);
int resolve_ip_http(fko_cli_options_t *options);
static void clean_exit(fko_ctx_t ctx, fko_cli_options_t *opts,
char *key, int *key_len, char *hmac_key, int *hmac_key_len,
unsigned int exit_status);
static void zero_buf_wrapper(char *buf, int len);
static int is_hostname_str_with_port(const char *str,
char *hostname, size_t hostname_bufsize, int *port);
#define MAX_CMDLINE_ARGS 50 /*!< should be way more than enough */
#define NAT_ACCESS_STR_TEMPLATE "%s,%d" /*!< Template for a nat access string ip,port with sscanf*/
#define HOSTNAME_BUFSIZE 64 /*!< Maximum size of a hostname string */
#define CTX_DUMP_BUFSIZE 4096 /*!< Maximum size allocated to a FKO context dump */
/**
* @brief Check whether a string is an ipv6 address or not
*
* @param str String to check for an ipv6 address.
*
* @return 1 if the string is an ipv6 address, 0 otherwise.
*/
static int
is_ipv6_str(char *str)
{
return 0;
}
/**
* @brief Check a string to find out if it is built as 'hostname,port'
*
* This function check if we can extract an hostname and a port from the string.
* If yes, we return 1, and both the hostname buffer and the port number are set
* accordingly.
*
* We could have used sscanf() here with a template "%[^,],%u", but this way we
* do not limit the size of the value copy in the hostname destination buffer.
* Limiting the string in the sscanf() can be done but would prevent any easy change
* for the hostname buffer size.
*
* @param str String to parse.
* @param hostname Buffer where to store the hostname value read from @str.
* @param hostname_bufsize Hostname buffer size.
* @param port Value of the port read from @str.
*
* @return 1 if the string is built as 'hostname,port', 0 otherwise.
*/
static int
is_hostname_str_with_port(const char *str, char *hostname, size_t hostname_bufsize, int *port)
{
int valid = 0; /* Result of the function */
char buf[MAX_LINE_LEN] = {0}; /* Copy of the buffer eg. "hostname,port" */
char *h; /* Pointer on the hostname string */
char *p; /* Ponter on the port string */
memset(hostname, 0, hostname_bufsize);
*port = 0;
/* Replace the comma in the string with a NULL char to split the
* buffer in two strings (hostname and port) */
strlcpy(buf, str, sizeof(buf));
p = strchr(buf, ',');
if(p != NULL)
{
*p++ = 0;
h = buf;
*port = atoi(p);
/* If the string does not match an ipv4 or ipv6 address we assume this
* is an hostname. We make sure the port is in the good range too */
if ( (is_valid_ipv4_addr(buf) == 0)
&& (is_ipv6_str(buf) == 0)
&& ((*port > 0) && (*port < 65536)) )
{
strlcpy(hostname, h, hostname_bufsize);
valid = 1;
}
/* The port is out of range or the ip is an ipv6 or ipv4 address */
else;
}
/* No port found in the string, let's skip */
else;
return valid;
}
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);
/* 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)
{
if(resolve_ip_http(&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);
}
/* 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(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);
}
/* 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. */
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 */
}
void
free_configs(fko_cli_options_t *opts)
{
if (opts->resolve_url != NULL)
free(opts->resolve_url);
zero_buf_wrapper(opts->key, MAX_KEY_LEN+1);
zero_buf_wrapper(opts->key_base64, MAX_B64_KEY_LEN+1);
zero_buf_wrapper(opts->hmac_key, MAX_KEY_LEN+1);
zero_buf_wrapper(opts->hmac_key_base64, MAX_B64_KEY_LEN+1);
zero_buf_wrapper(opts->gpg_recipient_key, MAX_GPG_KEY_ID);
zero_buf_wrapper(opts->gpg_signer_key, MAX_GPG_KEY_ID);
zero_buf_wrapper(opts->gpg_home_dir, MAX_PATH_LEN);
zero_buf_wrapper(opts->server_command, MAX_LINE_LEN);
}
static int
get_rand_port(fko_ctx_t ctx)
{
char *rand_val = NULL;
char port_str[MAX_PORT_STR_LEN+1] = {0};
int tmpint, is_err;
int port = 0;
int res = 0;
res = fko_get_rand_value(ctx, &rand_val);
if(res != FKO_SUCCESS)
{
errmsg("get_rand_port(), fko_get_rand_value", res);
return -1;
}
strlcpy(port_str, rand_val, sizeof(port_str));
tmpint = strtol_wrapper(port_str, 0, -1, NO_EXIT_UPON_ERR, &is_err);
if(is_err != FKO_SUCCESS)
{
log_msg(LOG_VERBOSITY_ERROR,
"[*] get_rand_port(), could not convert rand_val str '%s', to integer",
rand_val);
return -1;
}
/* Convert to a random value between 1024 and 65535
*/
port = (MIN_HIGH_PORT + (tmpint % (MAX_PORT - MIN_HIGH_PORT)));
/* Force libfko to calculate a new random value since we don't want to
* give anyone a hint (via the port value) about the contents of the
* encrypted SPA data.
*/
res = fko_set_rand_value(ctx, NULL);
if(res != FKO_SUCCESS)
{
errmsg("get_rand_port(), fko_get_rand_value", res);
return -1;
}
return port;
}
/* See if the string is of the format "<ipv4 addr>:<port>",
*/
static int
ipv4_str_has_port(char *str)
{
int o1, o2, o3, o4, p;
/* Force the ':' (if any) to a ','
*/
char *ndx = strchr(str, ':');
if(ndx != NULL)
*ndx = ',';
/* Check format and values.
*/
if((sscanf(str, "%u.%u.%u.%u,%u", &o1, &o2, &o3, &o4, &p)) == 5
&& o1 >= 0 && o1 <= 255
&& o2 >= 0 && o2 <= 255
&& o3 >= 0 && o3 <= 255
&& o4 >= 0 && o4 <= 255
&& p > 0 && p < 65536)
{
return 1;
}
return 0;
}
/* Set access buf
*/
static int
set_access_buf(fko_ctx_t ctx, fko_cli_options_t *options, char *access_buf)
{
char *ndx = NULL, tmp_nat_port[MAX_PORT_STR_LEN+1] = {0};
int nat_port = 0;
if(options->access_str[0] != 0x0)
{
if (options->nat_rand_port)
{
nat_port = get_rand_port(ctx);
options->nat_port = nat_port;
}
else if (options->nat_port)
nat_port = options->nat_port;
if(nat_port > 0 && nat_port <= MAX_PORT)
{
/* Replace the access string port with the NAT port since the
* NAT port is manually specified (--nat-port) or derived from
* random data (--nat-rand-port). In the NAT modes, the fwknopd
* server uses the port in the access string as the one to NAT,
* and access is granted via this translated port to whatever is
* specified with --nat-access <IP:port> (so this service is the
* utlimate target of the incoming connection after the SPA
* packet is sent).
*/
ndx = strchr(options->access_str, '/');
if(ndx == NULL)
{
log_msg(LOG_VERBOSITY_ERROR, "[*] Expecting <proto>/<port> for -A arg.");
return 0;
}
snprintf(access_buf, MAX_LINE_LEN, "%s%s",
options->allow_ip_str, ",");
/* This adds in the protocol + '/' char
*/
strlcat(access_buf, options->access_str,
strlen(access_buf) + (ndx - options->access_str) + 2);
if (strchr(ndx+1, '/') != NULL)
{
log_msg(LOG_VERBOSITY_ERROR,
"[*] NAT for multiple ports/protocols not yet supported.");
return 0;
}
/* Now add the NAT port
*/
snprintf(tmp_nat_port, MAX_PORT_STR_LEN+1, "%d", nat_port);
strlcat(access_buf, tmp_nat_port,
strlen(access_buf)+MAX_PORT_STR_LEN+1);
}
else
{
snprintf(access_buf, MAX_LINE_LEN, "%s%s%s",
options->allow_ip_str, ",", options->access_str);
}
}
else
{
snprintf(access_buf, MAX_LINE_LEN, "%s%s%s",
options->allow_ip_str, ",", "none/0");
}
return 1;
}
/* Set NAT access string
*/
static int
set_nat_access(fko_ctx_t ctx, fko_cli_options_t *options, const char * const access_buf)
{
char nat_access_buf[MAX_LINE_LEN] = {0};
char tmp_access_port[MAX_PORT_STR_LEN+1] = {0}, *ndx = NULL;
int access_port = 0, i = 0, is_err = 0;
char dst_ip_str[INET_ADDRSTRLEN] = {0};
char hostname[HOSTNAME_BUFSIZE] = {0};
int port = 0;
struct addrinfo hints;
memset(&hints, 0 , sizeof(hints));
ndx = strchr(options->access_str, '/');
if(ndx == NULL)
{
log_msg(LOG_VERBOSITY_ERROR, "[*] Expecting <proto>/<port> for -A arg.");
return FKO_ERROR_INVALID_DATA;
}
ndx++;
while(*ndx != '\0' && isdigit(*ndx) && i < MAX_PORT_STR_LEN)
{
tmp_access_port[i] = *ndx;
ndx++;
i++;
}
tmp_access_port[i] = '\0';
access_port = strtol_wrapper(tmp_access_port, 1,
MAX_PORT, NO_EXIT_UPON_ERR, &is_err);
if(is_err != FKO_SUCCESS)
{
log_msg(LOG_VERBOSITY_ERROR, "[*] Invalid port value '%d' for -A arg.",
access_port);
return FKO_ERROR_INVALID_DATA;
}
if (options->nat_local && options->nat_access_str[0] == 0x0)
{
snprintf(nat_access_buf, MAX_LINE_LEN, NAT_ACCESS_STR_TEMPLATE,
options->spa_server_str, access_port);
}
if (nat_access_buf[0] == 0x0 && options->nat_access_str[0] != 0x0)
{
if (ipv4_str_has_port(options->nat_access_str))
{
snprintf(nat_access_buf, MAX_LINE_LEN, "%s",
options->nat_access_str);
}
else
{
snprintf(nat_access_buf, MAX_LINE_LEN, NAT_ACCESS_STR_TEMPLATE,
options->nat_access_str, access_port);
}
}
/* Check if there is a hostname to resolve as an ip address in the NAT access buffer */
if (is_hostname_str_with_port(nat_access_buf, hostname, sizeof(hostname), &port))
{
/* Speed up the name resolution by forcing ipv4 (AF_INET).
* A NULL pointer could be used instead if there is no constraint.
* Maybe when ipv6 support will be enable the structure could initialize the
* family to either AF_INET or AF_INET6 */
hints.ai_family = AF_INET;
if (resolve_dest_adr(hostname, &hints, dst_ip_str, sizeof(dst_ip_str)) != 0)
{
log_msg(LOG_VERBOSITY_ERROR, "[*] Unable to resolve %s as an ip address",
hostname);
return FKO_ERROR_INVALID_DATA;
}
snprintf(nat_access_buf, MAX_LINE_LEN, NAT_ACCESS_STR_TEMPLATE,
dst_ip_str, port);
}
/* Nothing to resolve */
else;
if(options->nat_rand_port)
{
/* Must print to stdout what the random port is since
* if not then the user will not which port will be
* opened/NAT'd on the fwknopd side
*/
log_msg(LOG_VERBOSITY_NORMAL,
"[+] Randomly assigned port '%d' on: '%s' will grant access to: '%s'",
options->nat_port, access_buf, nat_access_buf);
}
return fko_set_spa_nat_access(ctx, nat_access_buf);
}
static int
prev_exec(fko_cli_options_t *options, int argc, char **argv)
{
char args_save_file[MAX_PATH_LEN] = {0};
int res = 1;
if(options->args_save_file[0] != 0x0)
{
strlcpy(args_save_file, options->args_save_file, sizeof(args_save_file));
}
else
{
if (get_save_file(args_save_file) != 1)
{
log_msg(LOG_VERBOSITY_ERROR, "Unable to determine args save file");
return 0;
}
}
if(options->run_last_command)
res = run_last_args(options, args_save_file);
else if(options->show_last_command)
res = show_last_command(args_save_file);
else if (!options->no_save_args)
res = save_args(argc, argv, args_save_file);
return res;
}
/* Show the last command that was executed
*/
static int
show_last_command(const char * const args_save_file)
{
char args_str[MAX_LINE_LEN] = {0};
FILE *args_file_ptr = NULL;
if(verify_file_perms_ownership(args_save_file) != 1)
return 0;
if ((args_file_ptr = fopen(args_save_file, "r")) == NULL) {
log_msg(LOG_VERBOSITY_ERROR, "Could not open args file: %s",
args_save_file);
return 0;
}
if ((fgets(args_str, MAX_LINE_LEN, args_file_ptr)) != NULL) {
log_msg(LOG_VERBOSITY_NORMAL, "Last fwknop client command line: %s", args_str);
} else {
log_msg(LOG_VERBOSITY_NORMAL, "Could not read line from file: %s", args_save_file);
}
fclose(args_file_ptr);
return 1;
}
/* Get the command line arguments from the previous invocation
*/
static int
run_last_args(fko_cli_options_t *options, const char * const args_save_file)
{
FILE *args_file_ptr = NULL;
int current_arg_ctr = 0;
int argc_new = 0;
int i = 0;
char args_str[MAX_LINE_LEN] = {0};
char arg_tmp[MAX_LINE_LEN] = {0};
char *argv_new[MAX_CMDLINE_ARGS]; /* should be way more than enough */
if(verify_file_perms_ownership(args_save_file) != 1)
return 0;
if ((args_file_ptr = fopen(args_save_file, "r")) == NULL)
{
log_msg(LOG_VERBOSITY_ERROR, "Could not open args file: %s",
args_save_file);
return 0;
}
if ((fgets(args_str, MAX_LINE_LEN, args_file_ptr)) != NULL)
{
args_str[MAX_LINE_LEN-1] = '\0';
if (options->verbose)
log_msg(LOG_VERBOSITY_NORMAL, "Executing: %s", args_str);
for (i=0; i < (int)strlen(args_str); i++)
{
if (!isspace(args_str[i]))
{
arg_tmp[current_arg_ctr] = args_str[i];
current_arg_ctr++;
}
else
{
arg_tmp[current_arg_ctr] = '\0';
argv_new[argc_new] = malloc(strlen(arg_tmp)+1);
if (argv_new[argc_new] == NULL)
{
log_msg(LOG_VERBOSITY_ERROR, "[*] malloc failure for cmd line arg.");
fclose(args_file_ptr);
return 0;
}
strlcpy(argv_new[argc_new], arg_tmp, strlen(arg_tmp)+1);
current_arg_ctr = 0;
argc_new++;
if(argc_new >= MAX_CMDLINE_ARGS)
{
log_msg(LOG_VERBOSITY_ERROR, "[*] max command line args exceeded.");
fclose(args_file_ptr);
return 0;
}
}
}
}
fclose(args_file_ptr);
/* Reset the options index so we can run through them again.
*/
optind = 0;
config_init(options, argc_new, argv_new);
/* Since we passed in our own copies, free up malloc'd memory
*/
for (i=0; i < argc_new; i++)
{
if(argv_new[i] == NULL)
break;
else
free(argv_new[i]);
}
return 1;
}
static int
get_save_file(char *args_save_file)
{
char *homedir = NULL;
int rv = 0;
#ifdef WIN32
homedir = getenv("USERPROFILE");
#else
homedir = getenv("HOME");
#endif
if (homedir != NULL) {
snprintf(args_save_file, MAX_PATH_LEN, "%s%c%s",
homedir, PATH_SEP, ".fwknop.run");
rv = 1;
}
return rv;
}
/* Save our command line arguments
*/
static int
save_args(int argc, char **argv, const char * const args_save_file)
{
char args_str[MAX_LINE_LEN] = {0};
int i = 0, args_str_len = 0, args_file_fd = -1;
args_file_fd = open(args_save_file, O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
if (args_file_fd == -1) {
log_msg(LOG_VERBOSITY_ERROR, "Could not open args file: %s",
args_save_file);
return 0;
}
else {
for (i=0; i < argc; i++) {
args_str_len += strlen(argv[i]);
if (args_str_len >= MAX_PATH_LEN) {
log_msg(LOG_VERBOSITY_ERROR, "argument string too long, exiting.");
close(args_file_fd);
return 0;
}
strlcat(args_str, argv[i], sizeof(args_str));
strlcat(args_str, " ", sizeof(args_str));
}
strlcat(args_str, "\n", sizeof(args_str));
if(write(args_file_fd, args_str, strlen(args_str))
!= strlen(args_str)) {
log_msg(LOG_VERBOSITY_WARNING,
"warning, did not write expected number of bytes to args save file");
}
close(args_file_fd);
}
return 1;
}
/* Set the SPA packet message type
*/
static int
set_message_type(fko_ctx_t ctx, fko_cli_options_t *options)
{
short message_type;
if(options->server_command[0] != 0x0)
{
message_type = FKO_COMMAND_MSG;
}
else if(options->nat_local)
{
if (options->fw_timeout >= 0)
message_type = FKO_CLIENT_TIMEOUT_LOCAL_NAT_ACCESS_MSG;
else
message_type = FKO_LOCAL_NAT_ACCESS_MSG;
}
else if(options->nat_access_str[0] != 0x0)
{
if (options->fw_timeout >= 0)
message_type = FKO_CLIENT_TIMEOUT_NAT_ACCESS_MSG;
else
message_type = FKO_NAT_ACCESS_MSG;
}
else
{
if (options->fw_timeout >= 0)
message_type = FKO_CLIENT_TIMEOUT_ACCESS_MSG;
else
message_type = FKO_ACCESS_MSG;
}
return fko_set_spa_message_type(ctx, message_type);
}
/* Prompt for and receive a user password.
*/
static int
get_keys(fko_ctx_t ctx, fko_cli_options_t *options,
char *key, int *key_len, char *hmac_key, int *hmac_key_len)
{
char *key_tmp = NULL, *hmac_key_tmp = NULL;
int use_hmac = 0, res = 0;
memset(key, 0x0, MAX_KEY_LEN+1);
memset(hmac_key, 0x0, MAX_KEY_LEN+1);
if(options->have_key)
{
strlcpy(key, options->key, MAX_KEY_LEN+1);
*key_len = strlen(key);
}
else if(options->have_base64_key)
{
*key_len = fko_base64_decode(options->key_base64,
(unsigned char *) options->key);
if(*key_len > 0 && *key_len < MAX_KEY_LEN)
{
memcpy(key, options->key, *key_len);
}
else
{
log_msg(LOG_VERBOSITY_ERROR, "[*] Invalid key length: '%d', must be in [1,%d]",
*key_len, MAX_KEY_LEN);
return 0;
}
}
else
{
/* If --get-key file was specified grab the key/password from it.
*/
if(options->get_key_file[0] != 0x0)
{
if(get_key_file(key, key_len, options->get_key_file, ctx, options) != 1)
{
return 0;
}
}
else if(options->use_gpg)
{
if(options->use_gpg_agent)
log_msg(LOG_VERBOSITY_NORMAL,
"[+] GPG mode set, signing passphrase acquired via gpg-agent");
else if(options->gpg_no_signing_pw)
log_msg(LOG_VERBOSITY_NORMAL,
"[+] GPG mode set, signing passphrase not required");
else if(strlen(options->gpg_signer_key))
{
key_tmp = getpasswd("Enter passphrase for signing: ", options->input_fd);
if(key_tmp == NULL)
{
log_msg(LOG_VERBOSITY_ERROR, "[*] getpasswd() key error.");
return 0;
}
strlcpy(key, key_tmp, MAX_KEY_LEN+1);
*key_len = strlen(key);
}
}
else
{
key_tmp = getpasswd("Enter encryption key: ", options->input_fd);
if(key_tmp == NULL)
{
log_msg(LOG_VERBOSITY_ERROR, "[*] getpasswd() key error.");
return 0;
}
strlcpy(key, key_tmp, MAX_KEY_LEN+1);
*key_len = strlen(key);
}
}
if(options->have_hmac_key)
{
strlcpy(hmac_key, options->hmac_key, MAX_KEY_LEN+1);
*hmac_key_len = strlen(hmac_key);
use_hmac = 1;
}
else if(options->have_hmac_base64_key)
{
*hmac_key_len = fko_base64_decode(options->hmac_key_base64,
(unsigned char *) options->hmac_key);
if(*hmac_key_len > MAX_KEY_LEN || *hmac_key_len < 0)
{
log_msg(LOG_VERBOSITY_ERROR,
"[*] Invalid decoded key length: '%d', must be in [0,%d]",
*hmac_key_len, MAX_KEY_LEN);
return 0;
}
memcpy(hmac_key, options->hmac_key, *hmac_key_len);
use_hmac = 1;
}
else if (options->use_hmac)
{
/* If --get-key file was specified grab the key/password from it.
*/
if(options->get_hmac_key_file[0] != 0x0)
{
if(get_key_file(hmac_key, hmac_key_len,
options->get_hmac_key_file, ctx, options) != 1)
{
return 0;
}
use_hmac = 1;
}
else
{
hmac_key_tmp = getpasswd("Enter HMAC key: ", options->input_fd);
if(hmac_key_tmp == NULL)
{
log_msg(LOG_VERBOSITY_ERROR, "[*] getpasswd() key error.");
return 0;
}
strlcpy(hmac_key, hmac_key_tmp, MAX_KEY_LEN+1);
*hmac_key_len = strlen(hmac_key);
use_hmac = 1;
}
}
if (use_hmac)
{
if(*hmac_key_len < 0 || *hmac_key_len > MAX_KEY_LEN)
{
log_msg(LOG_VERBOSITY_ERROR, "[*] Invalid HMAC key length: '%d', must be in [0,%d]",
*hmac_key_len, MAX_KEY_LEN);
return 0;
}
/* Make sure the same key is not used for both encryption and the HMAC
*/
if(*hmac_key_len == *key_len)
{
if(memcmp(hmac_key, key, *key_len) == 0)
{
log_msg(LOG_VERBOSITY_ERROR,
"[*] The encryption passphrase and HMAC key should not be identical, no SPA packet sent. Exiting.");
return 0;
}
}
res = fko_set_spa_hmac_type(ctx, options->hmac_type);
if(res != FKO_SUCCESS)
{
errmsg("fko_set_spa_hmac_type", res);
return 0;
}
}
return 1;
}
/* Display an FKO error message.
*/
void
errmsg(const char *msg, const int err) {
log_msg(LOG_VERBOSITY_ERROR, "%s: %s: Error %i - %s",
MY_NAME, msg, err, fko_errstr(err));
}
static void
zero_buf_wrapper(char *buf, int len)
{
if(buf == NULL || len == 0)
return;
if(zero_buf(buf, len) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_VERBOSITY_ERROR,
"[*] Could not zero out sensitive data buffer.");
return;
}
/* free up memory and exit
*/
static void
clean_exit(fko_ctx_t ctx, fko_cli_options_t *opts,
char *key, int *key_len, char *hmac_key, int *hmac_key_len,
unsigned int exit_status)
{
if(fko_destroy(ctx) == FKO_ERROR_ZERO_OUT_DATA)
log_msg(LOG_VERBOSITY_ERROR,
"[*] Could not zero out sensitive data buffer.");
ctx = NULL;
free_configs(opts);
zero_buf_wrapper(key, *key_len);
zero_buf_wrapper(hmac_key, *hmac_key_len);
*key_len = 0;
*hmac_key_len = 0;
exit(exit_status);
}
/***EOF***/
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