/* * Copyright (c) 1994 by the University of Southern California * * EXPORT OF THIS SOFTWARE from the United States of America may * require a specific license from the United States Government. * It is the responsibility of any person or organization contemplating * export to obtain such a license before exporting. * * WITHIN THAT CONSTRAINT, permission to copy, modify, and distribute * this software and its documentation in source and binary forms is * hereby granted, provided that any documentation or other materials * related to such distribution or use acknowledge that the software * was developed by the University of Southern California. * * DISCLAIMER OF WARRANTY. THIS SOFTWARE IS PROVIDED "AS IS". The * University of Southern California MAKES NO REPRESENTATIONS OR * WARRANTIES, EXPRESS OR IMPLIED. By way of example, but not * limitation, the University of Southern California MAKES NO * REPRESENTATIONS OR WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY * PARTICULAR PURPOSE. The University of Southern * California shall not be held liable for any liability nor for any * direct, indirect, or consequential damages with respect to any * claim by the user or distributor of the ksu software. * * KSU was writen by: Ari Medvinsky, ari@isi.edu */ #include "ksu.h" /******************************************************************* get_all_princ_from_file - retrieves all principal names from file pointed to by fp. *******************************************************************/ static void close_time PROTOTYPE((int, FILE *, int, FILE *)); static krb5_boolean find_str_in_list PROTOTYPE((char **, char *)); krb5_error_code get_all_princ_from_file (fp, plist) FILE *fp; char ***plist; { krb5_error_code retval; char * line, * fprinc, * lp, ** temp_list = NULL; int count = 0, chunk_count = 1; if (!(temp_list = (char **) malloc( CHUNK * sizeof(char *)))){ return errno; } if (retval = get_line(fp, &line )){ return retval; } while (line){ fprinc = get_first_token (line, &lp); if (fprinc ){ temp_list[count] = strdup(fprinc); count ++; } if(count == (chunk_count * CHUNK -1)){ chunk_count ++; if (!(temp_list = (char **) realloc(temp_list, chunk_count * CHUNK * sizeof(char *)))){ return errno; } } free (line); if (retval = get_line(fp, &line )){ return retval;} } temp_list[count] = NULL; *plist = temp_list; return 0; } /************************************************************* list_union - combines list1 and list2 into combined_list. the space for list1 and list2 is either freed or used by combined_list. **************************************************************/ krb5_error_code list_union(list1, list2, combined_list) char **list1; char **list2; char ***combined_list; { int c1 =0, c2 = 0, i=0, j=0; char ** tlist; if (! list1){ *combined_list = list2; return 0; } if (! list2){ *combined_list = list1; return 0; } while (list1[c1]) c1++; while (list2[c2]) c2++; if (!(tlist = (char **) calloc( c1 + c2 + 1, sizeof ( char *)))){ return errno; } i = 0; while(list1[i]){ tlist[i] = list1[i]; i++; } j = 0; while(list2[j]){ if(find_str_in_list(list1, list2[j])==FALSE){ tlist[i] = list2[j]; i++; } j++; } free (list1); free (list2); tlist[i]= NULL; *combined_list = tlist; return 0; } krb5_error_code filter(fp, cmd, k5users_list, k5users_filt_list) FILE *fp; char *cmd; char **k5users_list; char ***k5users_filt_list; { krb5_error_code retval =0; krb5_boolean found = FALSE; char * out_cmd = NULL; int i=0, j=0, found_count = 0, k=0; char ** temp_filt_list; *k5users_filt_list = NULL; if (! k5users_list){ return 0; } while(k5users_list[i]){ if (retval= k5users_lookup(fp, k5users_list[i], cmd, &found, &out_cmd)){ return retval; } if (found == FALSE){ free (k5users_list[i]); k5users_list[i] = NULL; if (out_cmd) gb_err = out_cmd; }else{ found_count ++; } i++; } if (! (temp_filt_list = (char **) calloc ( found_count +1, sizeof (char*)))){ return errno; } for(j= 0, k=0; j < i; j ++ ){ if (k5users_list[j]){ temp_filt_list[k] = k5users_list[j]; k++; } } temp_filt_list[k] = NULL; free (k5users_list); *k5users_filt_list = temp_filt_list; return 0; } krb5_error_code get_authorized_princ_names(luser, cmd, princ_list) const char *luser; char *cmd; char ***princ_list; { struct passwd *pwd; int k5login_flag =0; int k5users_flag =0; FILE * login_fp, * users_fp; char ** k5login_list = NULL, ** k5users_list = NULL; char ** k5users_filt_list = NULL; char ** combined_list = NULL; struct stat tb; krb5_error_code retval; *princ_list = NULL; /* no account => no access */ if ((pwd = getpwnam(luser)) == NULL) { return 0; } k5login_flag = stat(k5login_path, &tb); k5users_flag = stat(k5users_path, &tb); if (!k5login_flag){ if ((login_fp = fopen(k5login_path, "r")) == NULL) { return 0; } if ( fowner(login_fp, pwd->pw_uid) == FALSE){ close_time(k5users_flag,users_fp, k5login_flag,login_fp); return 0; } } if (!k5users_flag){ if ((users_fp = fopen(k5users_path, "r")) == NULL) { return 0; } if ( fowner(users_fp, pwd->pw_uid) == FALSE){ close_time(k5users_flag,users_fp, k5login_flag,login_fp); return 0; } if(retval = get_all_princ_from_file (users_fp, &k5users_list)){ close_time(k5users_flag,users_fp, k5login_flag,login_fp); return retval; } rewind(users_fp); if(retval = filter(users_fp,cmd, k5users_list, &k5users_filt_list)){ close_time(k5users_flag,users_fp, k5login_flag, login_fp); return retval; } } if (cmd){ *princ_list = k5users_filt_list; close_time(k5users_flag,users_fp, k5login_flag, login_fp); return 0; } if (!k5login_flag){ if(retval = get_all_princ_from_file (login_fp, &k5login_list)){ close_time(k5users_flag,users_fp, k5login_flag,login_fp); return retval; } } if(retval = list_union(k5login_list, k5users_filt_list, & combined_list)){ close_time(k5users_flag,users_fp, k5login_flag,login_fp); return retval; } *princ_list = combined_list ; close_time(k5users_flag,users_fp, k5login_flag,login_fp); return 0; } static void close_time(k5users_flag, users_fp, k5login_flag, login_fp) int k5users_flag; FILE *users_fp; int k5login_flag; FILE *login_fp; { if (!k5users_flag) fclose(users_fp); if (!k5login_flag) fclose(login_fp); } static krb5_boolean find_str_in_list(list , elm) char **list; char *elm; { int i=0; krb5_boolean found = FALSE; if (!list) return found; while (list[i] ){ if (!strcmp(list[i], elm)){ found = TRUE; break; } i++; } return found; } /********************************************************************** returns the principal that is closes to client (can be the the client himself). plist contains a principal list obtained from .k5login and .k5users file. A principal is picked that has the best chance of getting in. **********************************************************************/ krb5_error_code get_closest_principal(context, plist, client, found) krb5_context context; char **plist; krb5_principal *client; krb5_boolean *found; { krb5_error_code retval =0; krb5_principal temp_client, best_client = NULL; int i = 0, j=0, cnelem, pnelem; krb5_boolean got_one; *found = FALSE; if (! plist ) return 0; cnelem = krb5_princ_size(context, *client); while(plist[i]){ if (retval = krb5_parse_name(context, plist[i], &temp_client)){ return retval; } pnelem = krb5_princ_size(context, temp_client); if ( cnelem > pnelem){ i++; continue; } if (krb5_princ_realm(context, *client)->length == krb5_princ_realm(context, temp_client)->length && (!memcmp (krb5_princ_realm(context, *client)->data, krb5_princ_realm(context, temp_client)->data, krb5_princ_realm(context, temp_client)->length))){ got_one = TRUE; for(j =0; j < cnelem; j ++){ krb5_data *p1 = krb5_princ_component(context, *client, j); krb5_data *p2 = krb5_princ_component(context, temp_client, j); if ((p1->length != p2->length) || memcmp(p1->data,p2->data,p1->length)){ got_one = FALSE; break; } } if (got_one == TRUE){ if(best_client){ if(krb5_princ_size(context, best_client) > krb5_princ_size(context, temp_client)){ best_client = temp_client; } }else{ best_client = temp_client; } } } i++; } if (best_client) { *found = TRUE; *client = best_client; } return 0; } /**************************************************************** find_either_ticket checks to see whether there is a ticket for the end server or tgt, if neither is there the return FALSE, *****************************************************************/ krb5_error_code find_either_ticket (context, cc, client, end_server, found) krb5_context context; krb5_ccache cc; krb5_principal client; krb5_principal end_server; krb5_boolean *found; { krb5_principal kdc_server; krb5_error_code retval; krb5_boolean temp_found = FALSE; char * cc_source_name; struct stat st_temp; cc_source_name = krb5_cc_get_name(context, cc); if ( ! stat(cc_source_name, &st_temp)){ if (retval = find_ticket (context, cc, client, end_server, &temp_found)) { return retval; } if (temp_found == FALSE){ if (retval = krb5_tgtname(context, krb5_princ_realm(context, client), krb5_princ_realm(context, client), &kdc_server)){ return retval ; } if(retval = find_ticket (context, cc,client, kdc_server, &temp_found)) { return retval; } } else { if (auth_debug) printf("find_either_ticket: found end server ticket\n"); } } *found = temp_found; return 0; } krb5_error_code find_ticket (context, cc, client, server, found) krb5_context context; krb5_ccache cc; krb5_principal client; krb5_principal server; krb5_boolean *found; { krb5_creds tgt, tgtq; krb5_error_code retval; *found = FALSE; memset((char *) &tgtq, 0, sizeof(tgtq)); memset((char *) &tgt, 0, sizeof(tgt)); if (retval= krb5_copy_principal(context, client, &tgtq.client)){ return retval; } if (retval= krb5_copy_principal(context, server, &tgtq.server)){ return retval ; } retval = krb5_cc_retrieve_cred(context, cc, KRB5_TC_MATCH_SRV_NAMEONLY, &tgtq, &tgt); if (! retval) retval = krb5_check_exp(context, tgt.times); if (retval){ if ((retval != KRB5_CC_NOTFOUND) && (retval != KRB5KRB_AP_ERR_TKT_EXPIRED)){ return retval ; } } else{ *found = TRUE; return 0; } free(tgtq.server); free(tgtq.client); return 0; } krb5_error_code find_princ_in_list (context, princ, plist, found) krb5_context context; krb5_principal princ; char **plist; krb5_boolean *found; { int i=0; char * princname; krb5_error_code retval; *found = FALSE; if (!plist) return 0; if (retval = krb5_unparse_name(context, princ, &princname)){ return retval; } while (plist[i] ){ if (!strcmp(plist[i], princname)){ *found = TRUE; break; } i++; } return 0; } typedef struct princ_info { krb5_principal p; krb5_boolean found; }princ_info; /********************************************************************** get_best_princ_for_target - sets the client name, path_out gets set, if authorization is not possible path_out gets set to ... ***********************************************************************/ krb5_error_code get_best_princ_for_target(context, source_uid, target_uid, source_user, target_user, cc_source, options, cmd, hostname, client, path_out) krb5_context context; int source_uid; int target_uid; char *source_user; char *target_user; krb5_ccache cc_source; opt_info *options; char *cmd; char *hostname; krb5_principal *client; int *path_out; { princ_info princ_trials[10]; char * cc_source_name; krb5_principal cc_def_princ = NULL; krb5_principal temp_client; krb5_principal target_client; krb5_principal source_client; krb5_principal end_server; krb5_error_code retval; char ** aplist =NULL; krb5_boolean found = FALSE; struct stat tb; int count =0; int i; struct stat st_temp; *path_out = 0; /* -n option was specified client is set we are done */ if (options->princ){ return 0; } cc_source_name = krb5_cc_get_name(context, cc_source); if ( ! stat(cc_source_name, &st_temp)){ if (retval = krb5_cc_get_principal(context, cc_source, &cc_def_princ)){ return retval; } } if (retval=krb5_parse_name(context, target_user, &target_client)){ return retval; } if (retval=krb5_parse_name(context, source_user, &source_client)){ return retval; } if (source_uid == 0){ if (target_uid != 0){ *client = target_client; /* this will be used to restrict the cache copty */ }else{ if(cc_def_princ){ *client = cc_def_princ; }else{ *client = target_client; } } if (auth_debug){ printf(" GET_best_princ_for_target: via source_uid == 0\n"); } return 0; } /* from here on, the code is for source_uid != 0 */ if (source_uid && (source_uid == target_uid)){ if(cc_def_princ){ *client = cc_def_princ; }else{ *client = target_client; } if (auth_debug){ printf("GET_best_princ_for_target: via source_uid == target_uid\n"); } return 0; } /* if .k5users and .k5login do not exist */ if ( stat(k5login_path, &tb) && stat(k5users_path, &tb) ){ *client = target_client; if ( cmd){ *path_out = NOT_AUTHORIZED; } if (auth_debug){ printf(" GET_best_princ_for_target: via no auth files path\n"); } return 0; }else{ if (retval = get_authorized_princ_names(target_user, cmd, & aplist)){ return retval; } /* .k5users or .k5login exist, but no authorization */ if ((!aplist) || (!aplist[0])){ *path_out = NOT_AUTHORIZED; if (auth_debug){ printf( "GET_best_princ_for_target: via empty auth files path\n"); } return 0; } } if (retval = krb5_sname_to_principal(context, hostname, NULL, KRB5_NT_SRV_HST, &end_server)){ return retval; } /* first see if default principal of the source cache can get us in, then the target_user@realm, then the source_user@realm. If all of them fail, try any other ticket in the cache. */ if (cc_def_princ){ princ_trials[count ++].p = cc_def_princ; }else{ princ_trials[count ++].p = NULL; } princ_trials[count ++].p = target_client; princ_trials[count ++].p = source_client; for (i= 0; i < count; i ++){ princ_trials[i].found = FALSE; } for (i= 0; i < count; i ++){ if(princ_trials[i].p){ if (retval= find_princ_in_list(context, princ_trials[i].p, aplist, &found)){ return retval; } if ( found == TRUE){ princ_trials[i].found = TRUE; if (retval = find_either_ticket (context, cc_source, princ_trials[i].p, end_server, &found)){ return retval; } if (found == TRUE){ *client = princ_trials[i].p; if (auth_debug){ printf("GET_best_princ_for_target: via ticket file, choice #%d\n", i); } return 0; } } } } /* out of preferred principals, see if there is any ticket that will get us in */ i=0; while (aplist[i]){ if (retval = krb5_parse_name(context, aplist[i], &temp_client)){ return retval; } if (retval = find_either_ticket (context, cc_source, temp_client, end_server, &found)){ return retval; } if (found == TRUE){ if (auth_debug){ printf("GET_best_princ_for_target: via ticket file, choice: any ok ticket \n" ); } *client = temp_client; return 0; } krb5_free_principal(context, temp_client); i++; } /* no tickets qualified, select a principal, that may be used for password promting */ for (i=0; i < count; i ++){ if (princ_trials[i].found == TRUE){ *client = princ_trials[i].p; if (auth_debug){ printf( "GET_best_princ_for_target: via prompt passwd list choice #%d \n",i); } return 0; } } #ifdef PRINC_LOOK_AHEAD for (i=0; i < count; i ++){ if (princ_trials[i].p){ if(retval=krb5_copy_principal(context, princ_trials[i].p, &temp_client)){ return retval; } /* get the client name that is the closest to the three princ in trials */ if(retval=get_closest_principal(context, aplist, &temp_client, & found)){ return retval; } if (found == TRUE){ *client = temp_client; if (auth_debug){ printf( "GET_best_princ_for_target: via prompt passwd list choice: approximation of princ in trials # %d \n",i); } return 0; } krb5_free_principal(context, temp_client); } } #endif /* PRINC_LOOK_AHEAD */ if(auth_debug){ printf( "GET_best_princ_for_target: out of luck, can't get appropriate default principal\n"); } *path_out = NOT_AUTHORIZED; return 0; }