tunala.c

开源的ssl算法openssl,版本0.9.8H

#if defined(NO_BUFFER) || defined(NO_IP) || defined(NO_OPENSSL)
#error "Badness, NO_BUFFER, NO_IP or NO_OPENSSL is defined, turn them *off*"
#endif

/* Include our bits'n'pieces */
#include "tunala.h"


/********************************************/
/* Our local types that specify our "world" */
/********************************************/

/* These represent running "tunnels". Eg. if you wanted to do SSL in a
 * "message-passing" scanario, the "int" file-descriptors might be replaced by
 * thread or process IDs, and the "select" code might be replaced by message
 * handling code. Whatever. */
typedef struct _tunala_item_t {
	/* The underlying SSL state machine. This is a data-only processing unit
	 * and we communicate with it by talking to its four "buffers". */
	state_machine_t sm;
	/* The file-descriptors for the "dirty" (encrypted) side of the SSL
	 * setup. In actuality, this is typically a socket and both values are
	 * identical. */
	int dirty_read, dirty_send;
	/* The file-descriptors for the "clean" (unencrypted) side of the SSL
	 * setup. These could be stdin/stdout, a socket (both values the same),
	 * or whatever you like. */
	int clean_read, clean_send;
} tunala_item_t;

/* This structure is used as the data for running the main loop. Namely, in a
 * network format such as this, it is stuff for select() - but as pointed out,
 * when moving the real-world to somewhere else, this might be replaced by
 * something entirely different. It's basically the stuff that controls when
 * it's time to do some "work". */
typedef struct _select_sets_t {
	int max; /* As required as the first argument to select() */
	fd_set reads, sends, excepts; /* As passed to select() */
} select_sets_t;
typedef struct _tunala_selector_t {
	select_sets_t last_selected; /* Results of the last select() */
	select_sets_t next_select; /* What we'll next select on */
} tunala_selector_t;

/* This structure is *everything*. We do it to avoid the use of globals so that,
 * for example, it would be easier to shift things around between async-IO,
 * thread-based, or multi-fork()ed (or combinations thereof). */
typedef struct _tunala_world_t {
	/* The file-descriptor we "listen" on for new connections */
	int listen_fd;
	/* The array of tunnels */
	tunala_item_t *tunnels;
	/* the number of tunnels in use and allocated, respectively */
	unsigned int tunnels_used, tunnels_size;
	/* Our outside "loop" context stuff */
	tunala_selector_t selector;
	/* Our SSL_CTX, which is configured as the SSL client or server and has
	 * the various cert-settings and callbacks configured. */
	SSL_CTX *ssl_ctx;
	/* Simple flag with complex logic :-) Indicates whether we're an SSL
	 * server or an SSL client. */
	int server_mode;
} tunala_world_t;

/*****************************/
/* Internal static functions */
/*****************************/

static SSL_CTX *initialise_ssl_ctx(int server_mode, const char *engine_id,
		const char *CAfile, const char *cert, const char *key,
		const char *dcert, const char *dkey, const char *cipher_list,
		const char *dh_file, const char *dh_special, int tmp_rsa,
		int ctx_options, int out_state, int out_verify, int verify_mode,
		unsigned int verify_depth);
static void selector_init(tunala_selector_t *selector);
static void selector_add_listener(tunala_selector_t *selector, int fd);
static void selector_add_tunala(tunala_selector_t *selector, tunala_item_t *t);
static int selector_select(tunala_selector_t *selector);
/* This returns -1 for error, 0 for no new connections, or 1 for success, in
 * which case *newfd is populated. */
static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd);
static int tunala_world_new_item(tunala_world_t *world, int fd,
		const char *ip, unsigned short port, int flipped);
static void tunala_world_del_item(tunala_world_t *world, unsigned int idx);
static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item);

/*********************************************/
/* MAIN FUNCTION (and its utility functions) */
/*********************************************/

static const char *def_proxyhost = "127.0.0.1:443";
static const char *def_listenhost = "127.0.0.1:8080";
static int def_max_tunnels = 50;
static const char *def_cacert = NULL;
static const char *def_cert = NULL;
static const char *def_key = NULL;
static const char *def_dcert = NULL;
static const char *def_dkey = NULL;
static const char *def_engine_id = NULL;
static int def_server_mode = 0;
static int def_flipped = 0;
static const char *def_cipher_list = NULL;
static const char *def_dh_file = NULL;
static const char *def_dh_special = NULL;
static int def_tmp_rsa = 1;
static int def_ctx_options = 0;
static int def_verify_mode = 0;
static unsigned int def_verify_depth = 10;
static int def_out_state = 0;
static unsigned int def_out_verify = 0;
static int def_out_totals = 0;
static int def_out_conns = 0;

static const char *helpstring =
"\n'Tunala' (A tunneler with a New Zealand accent)\n"
"Usage: tunala [options], where options are from;\n"
" -listen [host:]<port>  (default = 127.0.0.1:8080)\n"
" -proxy <host>:<port>   (default = 127.0.0.1:443)\n"
" -maxtunnels <num>      (default = 50)\n"
" -cacert <path|NULL>    (default = NULL)\n"
" -cert <path|NULL>      (default = NULL)\n"
" -key <path|NULL>       (default = whatever '-cert' is)\n"
" -dcert <path|NULL>     (usually for DSA, default = NULL)\n"
" -dkey <path|NULL>      (usually for DSA, default = whatever '-dcert' is)\n"
" -engine <id|NULL>      (default = NULL)\n"
" -server <0|1>          (default = 0, ie. an SSL client)\n"
" -flipped <0|1>         (makes SSL servers be network clients, and vice versa)\n"
" -cipher <list>         (specifies cipher list to use)\n"
" -dh_file <path>        (a PEM file containing DH parameters to use)\n"
" -dh_special <NULL|generate|standard> (see below: def=NULL)\n"
" -no_tmp_rsa            (don't generate temporary RSA keys)\n"
" -no_ssl2               (disable SSLv2)\n"
" -no_ssl3               (disable SSLv3)\n"
" -no_tls1               (disable TLSv1)\n"
" -v_peer                (verify the peer certificate)\n"
" -v_strict              (do not continue if peer doesn't authenticate)\n"
" -v_once                (no verification in renegotiates)\n"
" -v_depth <num>         (limit certificate chain depth, default = 10)\n"
" -out_conns             (prints client connections and disconnections)\n"
" -out_state             (prints SSL handshake states)\n"
" -out_verify <0|1|2|3>  (prints certificate verification states: def=1)\n"
" -out_totals            (prints out byte-totals when a tunnel closes)\n"
" -<h|help|?>            (displays this help screen)\n"
"Notes:\n"
"(1) It is recommended to specify a cert+key when operating as an SSL server.\n"
"    If you only specify '-cert', the same file must contain a matching\n"
"    private key.\n"
"(2) Either dh_file or dh_special can be used to specify where DH parameters\n"
"    will be obtained from (or '-dh_special NULL' for the default choice) but\n"
"    you cannot specify both. For dh_special, 'generate' will create new DH\n"
"    parameters on startup, and 'standard' will use embedded parameters\n"
"    instead.\n"
"(3) Normally an ssl client connects to an ssl server - so that an 'ssl client\n"
"    tunala' listens for 'clean' client connections and proxies ssl, and an\n"
"    'ssl server tunala' listens for ssl connections and proxies 'clean'. With\n"
"    '-flipped 1', this behaviour is reversed so that an 'ssl server tunala'\n"
"    listens for clean client connections and proxies ssl (but participating\n"
"    as an ssl *server* in the SSL/TLS protocol), and an 'ssl client tunala'\n"
"    listens for ssl connections (participating as an ssl *client* in the\n"
"    SSL/TLS protocol) and proxies 'clean' to the end destination. This can\n"
"    be useful for allowing network access to 'servers' where only the server\n"
"    needs to authenticate the client (ie. the other way is not required).\n"
"    Even with client and server authentication, this 'technique' mitigates\n"
"    some DoS (denial-of-service) potential as it will be the network client\n"
"    having to perform the first private key operation rather than the other\n"
"    way round.\n"
"(4) The 'technique' used by setting '-flipped 1' is probably compatible with\n"
"    absolutely nothing except another complimentary instance of 'tunala'\n"
"    running with '-flipped 1'. :-)\n";

/* Default DH parameters for use with "-dh_special standard" ... stolen striaght
 * from s_server. */
static unsigned char dh512_p[]={
	0xDA,0x58,0x3C,0x16,0xD9,0x85,0x22,0x89,0xD0,0xE4,0xAF,0x75,
	0x6F,0x4C,0xCA,0x92,0xDD,0x4B,0xE5,0x33,0xB8,0x04,0xFB,0x0F,
	0xED,0x94,0xEF,0x9C,0x8A,0x44,0x03,0xED,0x57,0x46,0x50,0xD3,
	0x69,0x99,0xDB,0x29,0xD7,0x76,0x27,0x6B,0xA2,0xD3,0xD4,0x12,
	0xE2,0x18,0xF4,0xDD,0x1E,0x08,0x4C,0xF6,0xD8,0x00,0x3E,0x7C,
	0x47,0x74,0xE8,0x33,
	};
static unsigned char dh512_g[]={
	0x02,
	};

/* And the function that parses the above "standard" parameters, again, straight
 * out of s_server. */
static DH *get_dh512(void)
	{
	DH *dh=NULL;

	if ((dh=DH_new()) == NULL) return(NULL);
	dh->p=BN_bin2bn(dh512_p,sizeof(dh512_p),NULL);
	dh->g=BN_bin2bn(dh512_g,sizeof(dh512_g),NULL);
	if ((dh->p == NULL) || (dh->g == NULL))
		return(NULL);
	return(dh);
	}

/* Various help/error messages used by main() */
static int usage(const char *errstr, int isunknownarg)
{
	if(isunknownarg)
		fprintf(stderr, "Error: unknown argument '%s'\n", errstr);
	else
		fprintf(stderr, "Error: %s\n", errstr);
	fprintf(stderr, "%s\n", helpstring);
	return 1;
}

static int err_str0(const char *str0)
{
	fprintf(stderr, "%s\n", str0);
	return 1;
}

static int err_str1(const char *fmt, const char *str1)
{
	fprintf(stderr, fmt, str1);
	fprintf(stderr, "\n");
	return 1;
}

static int parse_max_tunnels(const char *s, unsigned int *maxtunnels)
{
	unsigned long l;
	if(!int_strtoul(s, &l) || (l < 1) || (l > 1024)) {
		fprintf(stderr, "Error, '%s' is an invalid value for "
				"maxtunnels\n", s);
		return 0;
	}
	*maxtunnels = (unsigned int)l;
	return 1;
}

static int parse_server_mode(const char *s, int *servermode)
{
	unsigned long l;
	if(!int_strtoul(s, &l) || (l > 1)) {
		fprintf(stderr, "Error, '%s' is an invalid value for the "
				"server mode\n", s);
		return 0;
	}
	*servermode = (int)l;
	return 1;
}

static int parse_dh_special(const char *s, const char **dh_special)
{
	if((strcmp(s, "NULL") == 0) || (strcmp(s, "generate") == 0) ||
			(strcmp(s, "standard") == 0)) {
		*dh_special = s;
		return 1;
	}
	fprintf(stderr, "Error, '%s' is an invalid value for 'dh_special'\n", s);
	return 0;
}

static int parse_verify_level(const char *s, unsigned int *verify_level)
{
	unsigned long l;
	if(!int_strtoul(s, &l) || (l > 3)) {
		fprintf(stderr, "Error, '%s' is an invalid value for "
				"out_verify\n", s);
		return 0;
	}
	*verify_level = (unsigned int)l;
	return 1;
}

static int parse_verify_depth(const char *s, unsigned int *verify_depth)
{
	unsigned long l;
	if(!int_strtoul(s, &l) || (l < 1) || (l > 50)) {
		fprintf(stderr, "Error, '%s' is an invalid value for "
				"verify_depth\n", s);
		return 0;
	}
	*verify_depth = (unsigned int)l;
	return 1;
}

/* Some fprintf format strings used when tunnels close */
static const char *io_stats_dirty =
"    SSL traffic;   %8lu bytes in, %8lu bytes out\n";
static const char *io_stats_clean =
"    clear traffic; %8lu bytes in, %8lu bytes out\n";

int main(int argc, char *argv[])
{
	unsigned int loop;
	int newfd;
	tunala_world_t world;
	tunala_item_t *t_item;
	const char *proxy_ip;
	unsigned short proxy_port;
	/* Overridables */
	const char *proxyhost = def_proxyhost;
	const char *listenhost = def_listenhost;
	unsigned int max_tunnels = def_max_tunnels;
	const char *cacert = def_cacert;
	const char *cert = def_cert;
	const char *key = def_key;
	const char *dcert = def_dcert;
	const char *dkey = def_dkey;
	const char *engine_id = def_engine_id;
	int server_mode = def_server_mode;
	int flipped = def_flipped;
	const char *cipher_list = def_cipher_list;
	const char *dh_file = def_dh_file;
	const char *dh_special = def_dh_special;
	int tmp_rsa = def_tmp_rsa;
	int ctx_options = def_ctx_options;
	int verify_mode = def_verify_mode;
	unsigned int verify_depth = def_verify_depth;
	int out_state = def_out_state;
	unsigned int out_verify = def_out_verify;
	int out_totals = def_out_totals;
	int out_conns = def_out_conns;

/* Parse command-line arguments */
next_arg:
	argc--; argv++;
	if(argc > 0) {
		if(strcmp(*argv, "-listen") == 0) {
			if(argc < 2)
				return usage("-listen requires an argument", 0);
			argc--; argv++;
			listenhost = *argv;
			goto next_arg;
		} else if(strcmp(*argv, "-proxy") == 0) {
			if(argc < 2)
				return usage("-proxy requires an argument", 0);
			argc--; argv++;
			proxyhost = *argv;
			goto next_arg;
		} else if(strcmp(*argv, "-maxtunnels") == 0) {
			if(argc < 2)
				return usage("-maxtunnels requires an argument", 0);
			argc--; argv++;
			if(!parse_max_tunnels(*argv, &max_tunnels))
				return 1;
			goto next_arg;
		} else if(strcmp(*argv, "-cacert") == 0) {
			if(argc < 2)
				return usage("-cacert requires an argument", 0);
			argc--; argv++;
			if(strcmp(*argv, "NULL") == 0)
				cacert = NULL;
			else
				cacert = *argv;
			goto next_arg;
		} else if(strcmp(*argv, "-cert") == 0) {
			if(argc < 2)
				return usage("-cert requires an argument", 0);
			argc--; argv++;
			if(strcmp(*argv, "NULL") == 0)
				cert = NULL;
			else
				cert = *argv;
			goto next_arg;
		} else if(strcmp(*argv, "-key") == 0) {
			if(argc < 2)
				return usage("-key requires an argument", 0);
			argc--; argv++;
			if(strcmp(*argv, "NULL") == 0)
				key = NULL;
			else
				key = *argv;
			goto next_arg;
		} else if(strcmp(*argv, "-dcert") == 0) {