1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/*
* in_tkt.c
*
* Copyright 1985, 1986, 1987, 1988 by the Massachusetts Institute
* of Technology.
*
* For copying and distribution information, please see the file
* <mit-copyright.h>.
*/
#include "mit-copyright.h"
#include <stdio.h>
#include <string.h>
#include "krb.h"
#include <fcntl.h>
#include <sys/stat.h>
#ifdef TKT_SHMEM
#include <sys/param.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
extern int krb_debug;
/*
* in_tkt() is used to initialize the ticket store. It creates the
* file to contain the tickets and writes the given user's name "pname"
* and instance "pinst" in the file. in_tkt() returns KSUCCESS on
* success, or KFAILURE if something goes wrong.
*/
#ifdef HAVE_SETEUID
#define do_seteuid(e) seteuid((e))
#else
#ifdef HAVE_SETRESUID
#define do_seteuid(e) setresuid(getuid(), (e), geteuid())
#else
#ifdef HAVE_SETREUID
#define do_seteuid(e) setreuid(geteuid(), (e))
#else
#define do_seteuid(e) (errno = EPERM, -1)
#endif
#endif
#endif
#ifndef O_SYNC
#define O_SYNC 0
#endif
KRB5_DLLIMP int KRB5_CALLCONV
in_tkt(pname,pinst)
char *pname;
char *pinst;
{
int tktfile;
uid_t me, metoo, getuid(), geteuid();
struct stat buf;
int count;
char *file = TKT_FILE;
int fd;
register int i;
char charbuf[BUFSIZ];
int mask;
#ifdef TKT_SHMEM
char shmidname[MAXPATHLEN];
#endif /* TKT_SHMEM */
/* If ticket cache selector is null, use default cache. */
if (file == 0)
file = tkt_string();
me = getuid ();
metoo = geteuid();
if (lstat(file,&buf) == 0) {
if (buf.st_uid != me || !(buf.st_mode & S_IFREG) ||
buf.st_mode & 077) {
if (krb_debug)
fprintf(stderr,"Error initializing %s",file);
return(KFAILURE);
}
/* file already exists, and permissions appear ok, so nuke it */
if ((fd = open(file, O_RDWR|O_SYNC, 0)) < 0)
goto out; /* can't zero it, but we can still try truncating it */
memset(charbuf, 0, sizeof(charbuf));
for (i = 0; i < buf.st_size; i += sizeof(charbuf))
if (write(fd, charbuf, sizeof(charbuf)) != sizeof(charbuf)) {
#ifndef NO_FSYNC
(void) fsync(fd);
#endif
(void) close(fd);
goto out;
}
#ifndef NO_FSYNC
(void) fsync(fd);
#endif
(void) close(fd);
}
out:
/* arrange so the file is owned by the ruid
(swap real & effective uid if necessary).
This isn't a security problem, since the ticket file, if it already
exists, has the right uid (== ruid) and mode. */
if (me != metoo) {
if (do_seteuid(me) < 0) {
/* can't switch??? barf! */
if (krb_debug)
perror("in_tkt: seteuid");
return(KFAILURE);
} else
if (krb_debug)
printf("swapped UID's %d and %d\n",metoo,me);
}
/* Set umask to ensure that we have write access on the created
ticket file. */
mask = umask(077);
if ((tktfile = creat(file,0600)) < 0) {
umask(mask);
if (krb_debug)
fprintf(stderr,"Error initializing %s",TKT_FILE);
return(KFAILURE);
}
umask(mask);
if (me != metoo) {
if (do_seteuid(metoo) < 0) {
/* can't switch??? barf! */
if (krb_debug)
perror("in_tkt: seteuid2");
return(KFAILURE);
} else
if (krb_debug)
printf("swapped UID's %d and %d\n",me,metoo);
}
if (lstat(file,&buf) < 0) {
if (krb_debug)
fprintf(stderr,"Error initializing %s",TKT_FILE);
return(KFAILURE);
}
if (buf.st_uid != me || !(buf.st_mode & S_IFREG) ||
buf.st_mode & 077) {
if (krb_debug)
fprintf(stderr,"Error initializing %s",TKT_FILE);
return(KFAILURE);
}
count = strlen(pname)+1;
if (write(tktfile,pname,count) != count) {
(void) close(tktfile);
return(KFAILURE);
}
count = strlen(pinst)+1;
if (write(tktfile,pinst,count) != count) {
(void) close(tktfile);
return(KFAILURE);
}
(void) close(tktfile);
#ifdef TKT_SHMEM
(void) strcpy(shmidname, file);
(void) strcat(shmidname, ".shm");
return(krb_shm_create(shmidname));
#else /* !TKT_SHMEM */
return(KSUCCESS);
#endif /* TKT_SHMEM */
}
|
