4.4BSD/usr/src/kerberosIV/kerberos/kerberos.c
/*
* $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;
instance = ptr + strlen(service) + 1;
rpkt = &rpkt_st;
klog(L_INI_REQ,
"Initial ticket request Host: %s User: \"%s\" \"%s\"",
inet_ntoa(client_host), req_name_ptr, req_inst_ptr, 0);
if (i = check_princ(req_name_ptr, req_inst_ptr, 0,
&a_name_data)) {
kerb_err_reply(client, pkt, i, lt);
return;
}
tk->length = 0; /* init */
if (strcmp(service, "krbtgt"))
klog(L_NTGT_INTK,
"INITIAL request from %s.%s for %s.%s",
req_name_ptr, req_inst_ptr, service, instance, 0);
/* this does all the checking */
if (i = check_princ(service, instance, lifetime,
&s_name_data)) {
kerb_err_reply(client, pkt, i, lt);
return;
}
/* Bound requested lifetime with service and user */
lifetime = min(req_life, ((u_long) s_name_data.max_life));
lifetime = min(lifetime, ((u_long) a_name_data.max_life));
#ifdef NOENCRYPTION
bzero(session_key, sizeof(C_Block));
#else
/* random session key */
random_key(session_key);
#endif
/* unseal server's key from master key */
bcopy(&s_name_data.key_low, key, 4);
bcopy(&s_name_data.key_high, ((long *) key) + 1, 4);
kdb_encrypt_key(key, key, master_key,
master_key_schedule, DECRYPT);
/* construct and seal the ticket */
krb_create_ticket(tk, k_flags, a_name_data.name,
a_name_data.instance, local_realm,
client_host.s_addr, session_key, lifetime, kerb_time.tv_sec,
s_name_data.name, s_name_data.instance, key);
bzero(key, sizeof(key));
bzero(key_s, sizeof(key_s));
/*
* get the user's key, unseal it from the server's key, and
* use it to seal the cipher
*/
/* a_name_data.key_low a_name_data.key_high */
bcopy(&a_name_data.key_low, key, 4);
bcopy(&a_name_data.key_high, ((long *) key) + 1, 4);
/* unseal the a_name key from the master key */
kdb_encrypt_key(key, key, master_key,
master_key_schedule, DECRYPT);
create_ciph(ciph, session_key, s_name_data.name,
s_name_data.instance, local_realm, lifetime,
s_name_data.key_version, tk, kerb_time.tv_sec, key);
/* clear session key */
bzero(session_key, sizeof(session_key));
bzero(key, sizeof(key));
/* always send a reply packet */
rpkt = create_auth_reply(req_name_ptr, req_inst_ptr,
req_realm_ptr, req_time_ws, 0, a_name_data.exp_date,
a_name_data.key_version, ciph);
sendto(f, rpkt->dat, rpkt->length, 0,
(struct sockaddr *)client, S_AD_SZ);
bzero(&a_name_data, sizeof(a_name_data));
bzero(&s_name_data, sizeof(s_name_data));
break;
}
case AUTH_MSG_APPL_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 */
char tktrlm[REALM_SZ];
n_appl_req++;
tk->length = 0;
k_flags = 0; /* various kerberos flags */
auth->length = 4 + strlen(pkt->dat + 3);
auth->length += (int) *(pkt->dat + auth->length) +
(int) *(pkt->dat + auth->length + 1) + 2;
bcopy(pkt->dat, auth->dat, auth->length);
strncpy(tktrlm, auth->dat + 3, REALM_SZ);
if (set_tgtkey(tktrlm)) {
lt = klog(L_ERR_UNK,
"FAILED realm %s unknown. Host: %s ",
tktrlm, inet_ntoa(client_host));
kerb_err_reply(client, pkt, kerno, lt);
return;
}
kerno = krb_rd_req(auth, "ktbtgt", tktrlm, client_host.s_addr,
ad, 0);
if (kerno) {
klog(L_ERR_UNK, "FAILED krb_rd_req from %s: %s",
inet_ntoa(client_host), krb_err_txt[kerno]);
kerb_err_reply(client, pkt, kerno, "krb_rd_req failed");
return;
}
ptr = (char *) pkt->dat + auth->length;
bcopy(ptr, &time_ws, 4);
ptr += 4;
req_life = (u_long) (*ptr++);
service = ptr;
instance = ptr + strlen(service) + 1;
klog(L_APPL_REQ, "APPL Request %s.%s@%s on %s for %s.%s",
ad->pname, ad->pinst, ad->prealm, inet_ntoa(client_host),
service, instance, 0);
if (strcmp(ad->prealm, tktrlm)) {
kerb_err_reply(client, pkt, KERB_ERR_PRINCIPAL_UNKNOWN,
"Can't hop realms");
return;
}
if (!strcmp(service, "changepw")) {
kerb_err_reply(client, pkt, KERB_ERR_PRINCIPAL_UNKNOWN,
"Can't authorize password changed based on TGT");
return;
}
kerno = check_princ(service, instance, req_life,
&s_name_data);
if (kerno) {
kerb_err_reply(client, pkt, kerno, lt);
return;
}
/* Bound requested lifetime with service and user */
lifetime = min(req_life,
(ad->life - ((kerb_time.tv_sec - ad->time_sec) / 300)));
lifetime = min(lifetime, ((u_long) s_name_data.max_life));
/* unseal server's key from master key */
bcopy(&s_name_data.key_low, key, 4);
bcopy(&s_name_data.key_high, ((long *) key) + 1, 4);
kdb_encrypt_key(key, key, master_key,
master_key_schedule, DECRYPT);
/* construct and seal the ticket */
#ifdef NOENCRYPTION
bzero(session_key, sizeof(C_Block));
#else
/* random session key */
random_key(session_key);
#endif
krb_create_ticket(tk, k_flags, ad->pname, ad->pinst,
ad->prealm, client_host.s_addr,
session_key, lifetime, kerb_time.tv_sec,
s_name_data.name, s_name_data.instance,
key);
bzero(key, sizeof(key));
bzero(key_s, sizeof(key_s));
create_ciph(ciph, session_key, service, instance,
local_realm,
lifetime, s_name_data.key_version, tk,
kerb_time.tv_sec, ad->session);
/* clear session key */
bzero(session_key, sizeof(session_key));
bzero(ad->session, sizeof(ad->session));
rpkt = create_auth_reply(ad->pname, ad->pinst,
ad->prealm, time_ws,
0, 0, 0, ciph);
sendto(f, rpkt->dat, rpkt->length, 0,
(struct sockaddr *)client, S_AD_SZ);
bzero(&s_name_data, sizeof(s_name_data));
break;
}
#ifdef notdef_DIE
case AUTH_MSG_DIE:
{
lt = klog(L_DEATH_REQ,
"Host: %s User: \"%s\" \"%s\" Kerberos killed",
inet_ntoa(client_host), req_name_ptr, req_inst_ptr, 0);
exit(0);
}
#endif notdef_DIE
default:
{
lt = klog(L_KRB_PERR,
"Unknown message type: %d from %s port %u",
req_msg_type, inet_ntoa(client_host),
ntohs(client->sin_port));
break;
}
}
}
/*
* setup_disc
*
* disconnect all descriptors, remove ourself from the process
* group that spawned us.
*/
setup_disc()
{
int s;
for (s = 0; s < 3; s++) {
(void) close(s);
}
(void) open("/dev/null", 0);
(void) dup2(0, 1);
(void) dup2(0, 2);
s = open("/dev/tty", 2);
if (s >= 0) {
ioctl(s, TIOCNOTTY, (struct sgttyb *) 0);
(void) close(s);
}
(void) chdir("/tmp");
return;
}
/*
* kerb_er_reply creates an error reply packet and sends it to the
* client.
*/
kerb_err_reply(client, pkt, err, string)
struct sockaddr_in *client;
KTEXT pkt;
long err;
char *string;
{
static KTEXT_ST e_pkt_st;
KTEXT e_pkt = &e_pkt_st;
static char e_msg[128];
strcpy(e_msg, "\nKerberos error -- ");
strcat(e_msg, string);
cr_err_reply(e_pkt, req_name_ptr, req_inst_ptr, req_realm_ptr,
req_time_ws, err, e_msg);
sendto(f, e_pkt->dat, e_pkt->length, 0, (struct sockaddr *)client, S_AD_SZ);
}
/*
* Make sure that database isn't stale.
*
* Exit if it is; we don't want to tell lies.
*/
static void check_db_age()
{
long age;
if (max_age != -1) {
/* Requires existance of kerb_get_db_age() */
gettimeofday(&kerb_time, 0);
age = kerb_get_db_age();
if (age == 0) {
klog(L_KRB_PERR, "Database currently being updated!");
hang();
}
if ((age + max_age) < kerb_time.tv_sec) {
klog(L_KRB_PERR, "Database out of date!");
hang();
/* NOTREACHED */
}
}
}
check_princ(p_name, instance, lifetime, p)
char *p_name;
char *instance;
unsigned lifetime;
Principal *p;
{
static int n;
static int more;
long trans;
n = kerb_get_principal(p_name, instance, p, 1, &more);
klog(L_ALL_REQ,
"Principal: \"%s\", Instance: \"%s\" Lifetime = %d n = %d",
p_name, instance, lifetime, n, 0);
if (n < 0) {
lt = klog(L_KRB_PERR, "Database unavailable!");
hang();
}
/*
* if more than one p_name, pick one, randomly create a session key,
* compute maximum lifetime, lookup authorizations if applicable,
* and stuff into cipher.
*/
if (n == 0) {
/* service unknown, log error, skip to next request */
lt = klog(L_ERR_UNK, "UNKNOWN \"%s\" \"%s\"", p_name,
instance, 0);
return KERB_ERR_PRINCIPAL_UNKNOWN;
}
if (more) {
/* not unique, log error */
lt = klog(L_ERR_NUN, "Principal NOT UNIQUE \"%s\" \"%s\"",
p_name, instance, 0);
return KERB_ERR_PRINCIPAL_NOT_UNIQUE;
}
/* If the user's key is null, we want to return an error */
if ((p->key_low == 0) && (p->key_high == 0)) {
/* User has a null key */
lt = klog(L_ERR_NKY, "Null key \"%s\" \"%s\"", p_name,
instance, 0);
return KERB_ERR_NULL_KEY;
}
if (master_key_version != p->kdc_key_ver) {
/* log error reply */
lt = klog(L_ERR_MKV,
"Key vers incorrect, KRB = %d, \"%s\" \"%s\" = %d",
master_key_version, p->name, p->instance, p->kdc_key_ver,
0);
return KERB_ERR_NAME_MAST_KEY_VER;
}
/* make sure the service hasn't expired */
if ((u_long) p->exp_date < (u_long) kerb_time.tv_sec) {
/* service did expire, log it */
lt = klog(L_ERR_SEXP,
"EXPIRED \"%s\" \"%s\" %s", p->name, p->instance,
stime(&(p->exp_date)), 0);
return KERB_ERR_NAME_EXP;
}
/* ok is zero */
return 0;
}
/* Set the key for krb_rd_req so we can check tgt */
set_tgtkey(r)
char *r; /* Realm for desired key */
{
int n;
static char lastrealm[REALM_SZ];
Principal p_st;
Principal *p = &p_st;
C_Block key;
if (!strcmp(lastrealm, r))
return (KSUCCESS);
log("Getting key for %s", r);
n = kerb_get_principal("krbtgt", r, p, 1, &more);
if (n == 0)
return (KFAILURE);
/* unseal tgt key from master key */
bcopy(&p->key_low, key, 4);
bcopy(&p->key_high, ((long *) key) + 1, 4);
kdb_encrypt_key(key, key, master_key,
master_key_schedule, DECRYPT);
krb_set_key(key, 0);
strcpy(lastrealm, r);
return (KSUCCESS);
}
static void
hang()
{
if (pause_int == -1) {
klog(L_KRB_PERR, "Kerberos will pause so as not to loop init");
for (;;)
pause();
} else {
char buf[256];
sprintf(buf, "Kerberos will wait %d seconds before dying so as not to loop init", pause_int);
klog(L_KRB_PERR, buf);
sleep(pause_int);
klog(L_KRB_PERR, "Do svedania....\n");
exit(1);
}
}