diff options
Diffstat (limited to 'eBones/krb/kuserok.c')
| -rw-r--r-- | eBones/krb/kuserok.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/eBones/krb/kuserok.c b/eBones/krb/kuserok.c new file mode 100644 index 0000000..cb1f708 --- /dev/null +++ b/eBones/krb/kuserok.c @@ -0,0 +1,195 @@ +/* + * Copyright 1987, 1988 by the Massachusetts Institute of Technology. + * For copying and distribution information, please see the file + * <Copyright.MIT>. + * + * kuserok: check if a kerberos principal has + * access to a local account + * + * from: kuserok.c,v 4.5 89/01/23 09:25:21 jtkohl Exp $ + * $Id: kuserok.c,v 1.2 1994/07/19 19:25:50 g89r4222 Exp $ + */ + +#ifndef lint +static char rcsid[] = +"$Id: kuserok.c,v 1.2 1994/07/19 19:25:50 g89r4222 Exp $"; +#endif lint + +#include <krb.h> +#include <stdio.h> +#include <pwd.h> +#include <sys/param.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include <sys/file.h> +#include <strings.h> + +#define OK 0 +#define NOTOK 1 +#define MAX_USERNAME 10 + +/* + * Given a Kerberos principal "kdata", and a local username "luser", + * determine whether user is authorized to login according to the + * authorization file ("~luser/.klogin" by default). Returns OK + * if authorized, NOTOK if not authorized. + * + * If there is no account for "luser" on the local machine, returns + * NOTOK. If there is no authorization file, and the given Kerberos + * name "kdata" translates to the same name as "luser" (using + * krb_kntoln()), returns OK. Otherwise, if the authorization file + * can't be accessed, returns NOTOK. Otherwise, the file is read for + * a matching principal name, instance, and realm. If one is found, + * returns OK, if none is found, returns NOTOK. + * + * The file entries are in the format: + * + * name.instance@realm + * + * one entry per line. + * + * The ATHENA_COMPAT code supports old-style Athena ~luser/.klogin + * file entries. See the file "kparse.c". + */ + +#ifdef ATHENA_COMPAT + +#include <kparse.h> + +/* + * The parmtable defines the keywords we will recognize with their + * default values, and keeps a pointer to the found value. The found + * value should be filled in with strsave(), since FreeParameterSet() + * will release memory for all non-NULL found strings. + * +*** NOTE WELL! *** + * + * The table below is very nice, but we cannot hard-code a default for the + * realm: we have to get the realm via krb_get_lrealm(). Even though the + * default shows as "from krb_get_lrealm, below", it gets changed in + * kuserok to whatever krb_get_lrealm() tells us. That code assumes that + * the realm will be the entry number in the table below, so if you + * change the order of the entries below, you have to change the + * #definition of REALM_SCRIPT to reflect it. + */ +#define REALM_SUBSCRIPT 1 +parmtable kparm[] = { + +/* keyword default found value */ +{"user", "", (char *) NULL}, +{"realm", "see krb_get_lrealm, below", (char *) NULL}, +{"instance", "", (char *) NULL}, +}; +#define KPARMS kparm,PARMCOUNT(kparm) +#endif ATHENA_COMPAT + +kuserok(kdata, luser) + AUTH_DAT *kdata; + char *luser; +{ + struct stat sbuf; + struct passwd *pwd; + char pbuf[MAXPATHLEN]; + int isok = NOTOK, rc; + FILE *fp; + char kuser[MAX_USERNAME]; + char principal[ANAME_SZ], inst[INST_SZ], realm[REALM_SZ]; + char linebuf[BUFSIZ]; + char *newline; + int gobble; +#ifdef ATHENA_COMPAT + char local_realm[REALM_SZ]; +#endif ATHENA_COMPAT + + /* no account => no access */ + if ((pwd = getpwnam(luser)) == NULL) { + return(NOTOK); + } + (void) strcpy(pbuf, pwd->pw_dir); + (void) strcat(pbuf, "/.klogin"); + + if (access(pbuf, F_OK)) { /* not accessible */ + /* + * if he's trying to log in as himself, and there is no .klogin file, + * let him. To find out, call + * krb_kntoln to convert the triple in kdata to a name which we can + * string compare. + */ + if (!krb_kntoln(kdata, kuser) && (strcmp(kuser, luser) == 0)) { + return(OK); + } + } + /* open ~/.klogin */ + if ((fp = fopen(pbuf, "r")) == NULL) { + return(NOTOK); + } + /* + * security: if the user does not own his own .klogin file, + * do not grant access + */ + if (fstat(fileno(fp), &sbuf)) { + fclose(fp); + return(NOTOK); + } + if (sbuf.st_uid != pwd->pw_uid) { + fclose(fp); + return(NOTOK); + } + +#ifdef ATHENA_COMPAT + /* Accept old-style .klogin files */ + + /* + * change the default realm from the hard-coded value to the + * accepted realm that Kerberos specifies. + */ + rc = krb_get_lrealm(local_realm, 1); + if (rc == KSUCCESS) + kparm[REALM_SUBSCRIPT].defvalue = local_realm; + else + return (rc); + + /* check each line */ + while ((isok != OK) && (rc = fGetParameterSet(fp, KPARMS)) != PS_EOF) { + switch (rc) { + case PS_BAD_KEYWORD: + case PS_SYNTAX: + while (((gobble = fGetChar(fp)) != EOF) && (gobble != '\n')); + break; + + case PS_OKAY: + isok = (ParmCompare(KPARMS, "user", kdata->pname) || + ParmCompare(KPARMS, "instance", kdata->pinst) || + ParmCompare(KPARMS, "realm", kdata->prealm)); + break; + + default: + break; + } + FreeParameterSet(kparm, PARMCOUNT(kparm)); + } + /* reset the stream for parsing new-style names, if necessary */ + rewind(fp); +#endif ATHENA_COMPAT + + /* check each line */ + while ((isok != OK) && (fgets(linebuf, BUFSIZ, fp) != NULL)) { + /* null-terminate the input string */ + linebuf[BUFSIZ-1] = '\0'; + newline = NULL; + /* nuke the newline if it exists */ + if (newline = index(linebuf, '\n')) + *newline = '\0'; + rc = kname_parse(principal, inst, realm, linebuf); + if (rc == KSUCCESS) { + isok = (strncmp(kdata->pname, principal, ANAME_SZ) || + strncmp(kdata->pinst, inst, INST_SZ) || + strncmp(kdata->prealm, realm, REALM_SZ)); + } + /* clean up the rest of the line if necessary */ + if (!newline) + while (((gobble = getc(fp)) != EOF) && gobble != '\n'); + } + fclose(fp); + return(isok); +} |
