kerberos.c

早期freebsd实现

/*
 * $Source: /usr/src/kerberosIV/kerberos/RCS/kerberos.c,v $
 * $Author: torek $
 *
 * Copyright 1985, 1986, 1987, 1988 by the Massachusetts Institute
 * of Technology.
 *
 * For copying and distribution information, please see the file
 * <mit-copyright.h>.
 */

#ifndef lint
static char *rcsid_kerberos_c =
"$Header: /usr/src/kerberosIV/kerberos/RCS/kerberos.c,v 4.22 93/05/16 00:27:07 torek Exp $";
#endif  lint

#include <mit-copyright.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <signal.h>
#include <sgtty.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/file.h>
#include <ctype.h>
#include <string.h>

#include <des.h>
#include <krb.h>
#include <klog.h>
#include <prot.h>
#include <krb_db.h>
#include <kdc.h>

extern int errno;

int     f;

/* XXX several files in libkdb know about this */
char *progname;

static Key_schedule master_key_schedule;
static C_Block master_key;

static struct timeval kerb_time;
static Principal a_name_data;	/* for requesting user */
static Principal s_name_data;	/* for services requested */
static C_Block session_key;
static C_Block user_key;
static C_Block service_key;
static u_char master_key_version;
static char k_instance[INST_SZ];
static char log_text[128];
static char *lt;
static int more;

static int mflag;		/* Are we invoked manually? */
static int lflag;		/* Have we set an alterate log file? */
static char *log_file;		/* name of alt. log file */
static int nflag;		/* don't check max age */
static int rflag;		/* alternate realm specified */

/* fields within the received request packet */
static u_char req_msg_type;
static u_char req_version;
static char *req_name_ptr;
static char *req_inst_ptr;
static char *req_realm_ptr;
static u_char req_no_req;
static u_long req_time_ws;

int req_act_vno = KRB_PROT_VERSION; /* Temporary for version skew */

static char local_realm[REALM_SZ];

/* statistics */
static long q_bytes;		/* current bytes remaining in queue */
static long q_n;		/* how many consecutive non-zero
				 * q_bytes   */
static long max_q_bytes;
static long max_q_n;
static long n_auth_req;
static long n_appl_req;
static long n_packets;
static long n_user;
static long n_server;

static long max_age = -1;
static long pause_int = -1;

static void check_db_age();
static void hang();

/*
 * Print usage message and exit.
 */
static void usage()
{
    fprintf(stderr, "Usage: %s [-s] [-m] [-n] [-p pause_seconds]%s%s\n", progname, 
	    " [-a max_age] [-l log_file] [-r realm]"
	    ," [database_pathname]"
	    );
    exit(1);
}


main(argc, argv)
    int     argc;
    char  **argv;
{
    struct sockaddr_in from;
    register int n;
    int     on = 1;
    int     child;
    struct servent *sp;
    int     fromlen;
    static KTEXT_ST pkt_st;
    KTEXT   pkt = &pkt_st;
    Principal *p;
    int     more, kerror;
    C_Block key;
    int c;
    struct sockaddr_in sin;
    extern char *optarg;
    extern int optind;

    progname = argv[0];

    while ((c = getopt(argc, argv, "snmp:a:l:r:")) != EOF) {
	switch(c) {
	case 's':
	    /*
	     * Set parameters to slave server defaults.
	     */
	    if (max_age == -1 && !nflag)
		max_age = ONE_DAY;	/* 24 hours */
	    if (pause_int == -1)
		pause_int = FIVE_MINUTES; /* 5 minutes */
	    if (lflag == 0) {
		log_file = KRBSLAVELOG;
		lflag++;
	    }
	    break;
	case 'n':
	    max_age = -1;	/* don't check max age. */
	    nflag++;
	    break;
	case 'm':
	    mflag++;		/* running manually; prompt for master key */
	    break;
	case 'p':
	    /* Set pause interval. */
	    if (!isdigit(optarg[0]))
		usage();
	    pause_int = atoi(optarg);
	    if ((pause_int < 5) ||  (pause_int > ONE_HOUR)) {
		fprintf(stderr, "pause_int must be between 5 and 3600 seconds.\n");
		usage();
	    }
	    break;
	case 'a':
	    /* Set max age. */
	    if (!isdigit(optarg[0])) 
		usage();
	    max_age = atoi(optarg);
	    if ((max_age < ONE_HOUR) || (max_age > THREE_DAYS)) {
		fprintf(stderr, "max_age must be between one hour and three days, in seconds\n");
		usage();
	    }
	    break;
	case 'l':
	    /* Set alternate log file */
	    lflag++;
	    log_file = optarg;
	    break;
	case 'r':
	    /* Set realm name */
	    rflag++;
	    strcpy(local_realm, optarg);
	    break;
	default:
	    usage();
	    break;
	}
    }

    if (optind == (argc-1)) {
	if (kerb_db_set_name(argv[optind]) != 0) {
	    fprintf(stderr, "Could not set alternate database name\n");
	    exit(1);
	}
	optind++;
    }

    if (optind != argc)
	usage();
	
    printf("Kerberos server starting\n");
    
    if ((!nflag) && (max_age != -1))
	printf("\tMaximum database age: %d seconds\n", max_age);
    if (pause_int != -1)
	printf("\tSleep for %d seconds on error\n", pause_int);
    else
	printf("\tSleep forever on error\n");
    if (mflag)
	printf("\tMaster key will be entered manually\n");
    
    printf("\tLog file is %s\n", lflag ? log_file : KRBLOG);

    if (lflag)
	kset_logfile(log_file);
    
    /* find our hostname, and use it as the instance */
    if (gethostname(k_instance, INST_SZ)) {
	fprintf(stderr, "%s: gethostname error\n", progname);
	exit(1);
    }

    if ((sp = getservbyname("kerberos", "udp")) == 0) {
	fprintf(stderr, "%s: udp/kerberos unknown service\n", progname);
	exit(1);
    }
    bzero(&sin, sizeof(sin));
    sin.sin_family = AF_INET;
    sin.sin_port = sp->s_port;

    if ((f = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
	fprintf(stderr, "%s: Can't open socket\n", progname);
	exit(1);
    }
    if (setsockopt(f, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
	fprintf(stderr, "%s: setsockopt (SO_REUSEADDR)\n", progname);

    if (bind(f, (struct sockaddr *)&sin, S_AD_SZ) < 0) {
	fprintf(stderr, "%s: Can't bind socket\n", progname);
	exit(1);
    }
    /* do all the database and cache inits */
    if (n = kerb_init()) {
	if (mflag) {
	    printf("Kerberos db and cache init ");
	    printf("failed = %d ...exiting\n", n);
	    exit(-1);
	} else {
	    klog(L_KRB_PERR,
	    "Kerberos db and cache init failed = %d ...exiting", n);
	    hang();
	}
    }

    /* Make sure database isn't stale */
    check_db_age();
    
    /* setup master key */
    if (kdb_get_master_key (mflag, master_key, master_key_schedule) != 0) {
      klog (L_KRB_PERR, "kerberos: couldn't get master key.\n");
      exit (-1);
    }
    kerror = kdb_verify_master_key (master_key, master_key_schedule, stdout);
    if (kerror < 0) {
      klog (L_KRB_PERR, "Can't verify master key.");
      bzero (master_key, sizeof (master_key));
      bzero (master_key_schedule, sizeof (master_key_schedule));
      exit (-1);
    }

    master_key_version = (u_char) kerror;

    fprintf(stdout, "\nCurrent Kerberos master key version is %d\n",
	    master_key_version);

    if (!rflag) {
	/* Look up our local realm */
	krb_get_lrealm(local_realm, 1);
    }
    fprintf(stdout, "Local realm: %s\n", local_realm);
    fflush(stdout);

    if (set_tgtkey(local_realm)) {
	/* Ticket granting service unknown */
	klog(L_KRB_PERR, "Ticket granting ticket service unknown");
	fprintf(stderr, "Ticket granting ticket service unknown\n");
	exit(1);
    }
    if (mflag) {
	if ((child = fork()) != 0) {
	    printf("Kerberos started, PID=%d\n", child);
	    exit(0);
	}
	setup_disc();
    }
    /* receive loop */
    for (;;) {
	fromlen = S_AD_SZ;
	n = recvfrom(f, pkt->dat, MAX_PKT_LEN, 0,
	    (struct sockaddr *)&from, &fromlen);
	if (n > 0) {
	    pkt->length = n;
	    pkt->mbz = 0; /* force zeros to catch runaway strings */
	    /* see what is left in the input queue */
	    ioctl(f, FIONREAD, &q_bytes);
	    gettimeofday(&kerb_time, NULL);
	    q_n++;
	    max_q_n = max(max_q_n, q_n);
	    n_packets++;
	    klog(L_NET_INFO,
	 "q_byt %d, q_n %d, rd_byt %d, mx_q_b %d, mx_q_n %d, n_pkt %d",
		 q_bytes, q_n, n, max_q_bytes, max_q_n, n_packets, 0);
	    max_q_bytes = max(max_q_bytes, q_bytes);
	    if (!q_bytes)
		q_n = 0;	/* reset consecutive packets */
	    kerberos(&from, pkt);
	} else
	    klog(L_NET_ERR,
	    "%s: bad recvfrom n = %d errno = %d", progname, n, errno, 0);
    }
}


kerberos(client, pkt)
    struct sockaddr_in *client;
    KTEXT   pkt;
{
    static KTEXT_ST rpkt_st;
    KTEXT   rpkt = &rpkt_st;
    static KTEXT_ST ciph_st;
    KTEXT   ciph = &ciph_st;
    static KTEXT_ST tk_st;
    KTEXT   tk = &tk_st;
    static KTEXT_ST auth_st;
    KTEXT   auth = &auth_st;
    AUTH_DAT ad_st;
    AUTH_DAT *ad = &ad_st;


    static struct in_addr client_host;
    static int msg_byte_order;
    static int swap_bytes;
    static u_char k_flags;
    char   *p_name, *instance;
    u_long  lifetime;
    int     i;
    C_Block key;
    Key_schedule key_s;
    char   *ptr;



    ciph->length = 0;

    client_host = client->sin_addr;

    /* eval macros and correct the byte order and alignment as needed */
    req_version = pkt_version(pkt);	/* 1 byte, version */
    req_msg_type = pkt_msg_type(pkt);	/* 1 byte, Kerberos msg type */

    req_act_vno = req_version;

    /* check packet version */
    if (req_version != KRB_PROT_VERSION) {
	lt = klog(L_KRB_PERR,
	"KRB prot version mismatch: KRB =%d request = %d",
		  KRB_PROT_VERSION, req_version, 0);
	/* send an error reply */
	kerb_err_reply(client, pkt, KERB_ERR_PKT_VER, lt);
	return;
    }
    msg_byte_order = req_msg_type & 1;

    swap_bytes = 0;
    if (msg_byte_order != HOST_BYTE_ORDER) {
	swap_bytes++;
    }
    klog(L_KRB_PINFO,
	"Prot version: %d, Byte order: %d, Message type: %d",
	 req_version, msg_byte_order, req_msg_type);

    switch (req_msg_type & ~1) {

    case AUTH_MSG_KDC_REQUEST:
	{
	    u_long  time_ws;	/* Workstation time */
	    u_long  req_life;	/* Requested liftime */
	    char   *service;	/* Service name */
	    char   *instance;	/* Service instance */
	    int     kerno;	/* Kerberos error number */
	    n_auth_req++;
	    tk->length = 0;
	    k_flags = 0;	/* various kerberos flags */


	    /* set up and correct for byte order and alignment */
	    req_name_ptr = (char *) pkt_a_name(pkt);
	    req_inst_ptr = (char *) pkt_a_inst(pkt);
	    req_realm_ptr = (char *) pkt_a_realm(pkt);
	    bcopy(pkt_time_ws(pkt), &req_time_ws, sizeof(req_time_ws));
	    /* time has to be diddled */
	    if (swap_bytes) {
		swap_u_long(req_time_ws);
	    }
	    ptr = (char *) pkt_time_ws(pkt) + 4;

	    req_life = (u_long) (*ptr++);

	    service = ptr;