1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 static char sccsid[] = "@(#)klogin.c 5.9 (Berkeley) 06/02/91"; 10 #endif /* not lint */ 11 12 #ifdef KERBEROS 13 #include <sys/param.h> 14 #include <sys/syslog.h> 15 #include <kerberosIV/des.h> 16 #include <kerberosIV/krb.h> 17 #include <pwd.h> 18 #include <netdb.h> 19 20 #define INITIAL_TICKET "krbtgt" 21 #define VERIFY_SERVICE "rcmd" 22 23 extern int notickets; 24 extern char *krbtkfile_env; 25 26 /* 27 * Attempt to log the user in using Kerberos authentication 28 * 29 * return 0 on success (will be logged in) 30 * 1 if Kerberos failed (try local password in login) 31 */ 32 33 klogin(pw, instance, localhost, password) 34 struct passwd *pw; 35 char *instance, *localhost, *password; 36 { 37 int kerror; 38 AUTH_DAT authdata; 39 KTEXT_ST ticket; 40 struct hostent *hp; 41 unsigned long faddr; 42 char realm[REALM_SZ], savehost[MAXHOSTNAMELEN]; 43 char tkt_location[MAXPATHLEN]; 44 45 /* 46 * Root logins don't use Kerberos. 47 * If we have a realm, try getting a ticket-granting ticket 48 * and using it to authenticate. Otherwise, return 49 * failure so that we can try the normal passwd file 50 * for a password. If that's ok, log the user in 51 * without issuing any tickets. 52 */ 53 if (strcmp(pw->pw_name, "root") == 0 || 54 krb_get_lrealm(realm, 0) != KSUCCESS) 55 return (1); 56 57 /* 58 * get TGT for local realm 59 * tickets are stored in a file named TKT_ROOT plus uid 60 * except for user.root tickets. 61 */ 62 63 if (strcmp(instance, "root") != 0) 64 (void)sprintf(tkt_location, "%s%d", TKT_ROOT, pw->pw_uid); 65 else { 66 (void)sprintf(tkt_location, "%s_root_%d", TKT_ROOT, pw->pw_uid); 67 krbtkfile_env = tkt_location; 68 } 69 (void)krb_set_tkt_string(tkt_location); 70 71 /* 72 * Set real as well as effective ID to 0 for the moment, 73 * to make the kerberos library do the right thing. 74 */ 75 if (setuid(0) < 0) { 76 perror("login: setuid"); 77 return (1); 78 } 79 kerror = krb_get_pw_in_tkt(pw->pw_name, instance, 80 realm, INITIAL_TICKET, realm, DEFAULT_TKT_LIFE, password); 81 /* 82 * If we got a TGT, get a local "rcmd" ticket and check it so as to 83 * ensure that we are not talking to a bogus Kerberos server. 84 * 85 * There are 2 cases where we still allow a login: 86 * 1: the VERIFY_SERVICE doesn't exist in the KDC 87 * 2: local host has no srvtab, as (hopefully) indicated by a 88 * return value of RD_AP_UNDEC from krb_rd_req(). 89 */ 90 if (kerror != INTK_OK) { 91 if (kerror != INTK_BADPW && kerror != KDC_PR_UNKNOWN) { 92 syslog(LOG_ERR, "Kerberos intkt error: %s", 93 krb_err_txt[kerror]); 94 dest_tkt(); 95 } 96 return (1); 97 } 98 99 if (chown(TKT_FILE, pw->pw_uid, pw->pw_gid) < 0) 100 syslog(LOG_ERR, "chown tkfile (%s): %m", TKT_FILE); 101 102 (void)strncpy(savehost, krb_get_phost(localhost), sizeof(savehost)); 103 savehost[sizeof(savehost)-1] = NULL; 104 105 /* 106 * if the "VERIFY_SERVICE" doesn't exist in the KDC for this host, 107 * still allow login with tickets, but log the error condition. 108 */ 109 110 kerror = krb_mk_req(&ticket, VERIFY_SERVICE, savehost, realm, 33); 111 if (kerror == KDC_PR_UNKNOWN) { 112 syslog(LOG_NOTICE, 113 "warning: TGT not verified (%s); %s.%s not registered, or srvtab is wrong?", 114 krb_err_txt[kerror], VERIFY_SERVICE, savehost); 115 notickets = 0; 116 return(0); 117 } 118 119 if (kerror != KSUCCESS) { 120 (void)printf("unable to use TGT: (%s)\n", krb_err_txt[kerror]); 121 syslog(LOG_NOTICE, "unable to use TGT: (%s)", 122 krb_err_txt[kerror]); 123 dest_tkt(); 124 return(1); 125 } 126 127 if (!(hp = gethostbyname(localhost))) { 128 syslog(LOG_ERR, "couldn't get local host address"); 129 dest_tkt(); 130 return(1); 131 } 132 133 bcopy((void *)hp->h_addr, (void *)&faddr, sizeof(faddr)); 134 135 kerror = krb_rd_req(&ticket, VERIFY_SERVICE, savehost, faddr, 136 &authdata, ""); 137 138 if (kerror == KSUCCESS) { 139 notickets = 0; 140 return(0); 141 } 142 143 /* undecipherable: probably didn't have a srvtab on the local host */ 144 if (kerror = RD_AP_UNDEC) { 145 syslog(LOG_NOTICE, "krb_rd_req: (%s)\n", krb_err_txt[kerror]); 146 dest_tkt(); 147 return(1); 148 } 149 /* failed for some other reason */ 150 (void)printf("unable to verify %s ticket: (%s)\n", VERIFY_SERVICE, 151 krb_err_txt[kerror]); 152 syslog(LOG_NOTICE, "couldn't verify %s ticket: %s", VERIFY_SERVICE, 153 krb_err_txt[kerror]); 154 dest_tkt(); 155 return(1); 156 } 157 #endif 158