diff options
author | Damien Miller <djm@mindrot.org> | 1999-10-27 13:42:43 +1000 |
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committer | Damien Miller <djm@mindrot.org> | 1999-10-27 13:42:43 +1000 |
commit | d4a8b7e34dd619a4debf9a206c81db26d1402ea6 (patch) | |
tree | a47d770a2f790f40d18b0982d4e55fa7cfb1fa3b /auth-krb4.c |
Initial revision
Diffstat (limited to 'auth-krb4.c')
-rw-r--r-- | auth-krb4.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/auth-krb4.c b/auth-krb4.c new file mode 100644 index 000000000..720f3a4c4 --- /dev/null +++ b/auth-krb4.c | |||
@@ -0,0 +1,209 @@ | |||
1 | /* | ||
2 | |||
3 | auth-kerberos.c | ||
4 | |||
5 | Dug Song <dugsong@UMICH.EDU> | ||
6 | |||
7 | Kerberos v4 authentication and ticket-passing routines. | ||
8 | |||
9 | $Id: auth-krb4.c,v 1.1 1999/10/27 03:42:43 damien Exp $ | ||
10 | */ | ||
11 | |||
12 | #include "includes.h" | ||
13 | #include "packet.h" | ||
14 | #include "xmalloc.h" | ||
15 | #include "ssh.h" | ||
16 | |||
17 | #ifdef KRB4 | ||
18 | int ssh_tf_init(uid_t uid) | ||
19 | { | ||
20 | extern char *ticket; | ||
21 | char *tkt_root = TKT_ROOT; | ||
22 | struct stat st; | ||
23 | int fd; | ||
24 | |||
25 | /* Set unique ticket string manually since we're still root. */ | ||
26 | ticket = xmalloc(MAXPATHLEN); | ||
27 | #ifdef AFS | ||
28 | if (lstat("/ticket", &st) != -1) | ||
29 | tkt_root = "/ticket/"; | ||
30 | #endif /* AFS */ | ||
31 | snprintf(ticket, MAXPATHLEN, "%s%d_%d", tkt_root, uid, getpid()); | ||
32 | (void) krb_set_tkt_string(ticket); | ||
33 | |||
34 | /* Make sure we own this ticket file, and we created it. */ | ||
35 | if (lstat(ticket, &st) == -1 && errno == ENOENT) { | ||
36 | /* good, no ticket file exists. create it. */ | ||
37 | if ((fd = open(ticket, O_RDWR|O_CREAT|O_EXCL, 0600)) != -1) { | ||
38 | close(fd); | ||
39 | return 1; | ||
40 | } | ||
41 | } | ||
42 | else { | ||
43 | /* file exists. make sure server_user owns it (e.g. just passed ticket), | ||
44 | and that it isn't a symlink, and that it is mode 600. */ | ||
45 | if (st.st_mode == (S_IFREG|S_IRUSR|S_IWUSR) && st.st_uid == uid) | ||
46 | return 1; | ||
47 | } | ||
48 | /* Failure. */ | ||
49 | log("WARNING: bad ticket file %s", ticket); | ||
50 | return 0; | ||
51 | } | ||
52 | |||
53 | int auth_krb4(const char *server_user, KTEXT auth, char **client) | ||
54 | { | ||
55 | AUTH_DAT adat = { 0 }; | ||
56 | KTEXT_ST reply; | ||
57 | char instance[INST_SZ]; | ||
58 | int r, s; | ||
59 | u_int cksum; | ||
60 | Key_schedule schedule; | ||
61 | struct sockaddr_in local, foreign; | ||
62 | |||
63 | s = packet_get_connection_in(); | ||
64 | |||
65 | r = sizeof(local); | ||
66 | memset(&local, 0, sizeof(local)); | ||
67 | if (getsockname(s, (struct sockaddr *) &local, &r) < 0) | ||
68 | debug("getsockname failed: %.100s", strerror(errno)); | ||
69 | r = sizeof(foreign); | ||
70 | memset(&foreign, 0, sizeof(foreign)); | ||
71 | if (getpeername(s, (struct sockaddr *)&foreign, &r) < 0) | ||
72 | debug("getpeername failed: %.100s", strerror(errno)); | ||
73 | |||
74 | instance[0] = '*'; instance[1] = 0; | ||
75 | |||
76 | /* Get the encrypted request, challenge, and session key. */ | ||
77 | if ((r = krb_rd_req(auth, KRB4_SERVICE_NAME, instance, 0, &adat, ""))) { | ||
78 | packet_send_debug("Kerberos V4 krb_rd_req: %.100s", krb_err_txt[r]); | ||
79 | return 0; | ||
80 | } | ||
81 | des_key_sched((des_cblock *)adat.session, schedule); | ||
82 | |||
83 | *client = xmalloc(MAX_K_NAME_SZ); | ||
84 | (void) snprintf(*client, MAX_K_NAME_SZ, "%s%s%s@%s", adat.pname, | ||
85 | *adat.pinst ? "." : "", adat.pinst, adat.prealm); | ||
86 | |||
87 | /* Check ~/.klogin authorization now. */ | ||
88 | if (kuserok(&adat, (char *)server_user) != KSUCCESS) { | ||
89 | packet_send_debug("Kerberos V4 .klogin authorization failed!"); | ||
90 | log("Kerberos V4 .klogin authorization failed for %s to account %s", | ||
91 | *client, server_user); | ||
92 | return 0; | ||
93 | } | ||
94 | /* Increment the checksum, and return it encrypted with the session key. */ | ||
95 | cksum = adat.checksum + 1; | ||
96 | cksum = htonl(cksum); | ||
97 | |||
98 | /* If we can't successfully encrypt the checksum, we send back an empty | ||
99 | message, admitting our failure. */ | ||
100 | if ((r = krb_mk_priv((u_char *)&cksum, reply.dat, sizeof(cksum)+1, | ||
101 | schedule, &adat.session, &local, &foreign)) < 0) { | ||
102 | packet_send_debug("Kerberos V4 mk_priv: (%d) %s", r, krb_err_txt[r]); | ||
103 | reply.dat[0] = 0; | ||
104 | reply.length = 0; | ||
105 | } | ||
106 | else | ||
107 | reply.length = r; | ||
108 | |||
109 | /* Clear session key. */ | ||
110 | memset(&adat.session, 0, sizeof(&adat.session)); | ||
111 | |||
112 | packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE); | ||
113 | packet_put_string((char *) reply.dat, reply.length); | ||
114 | packet_send(); | ||
115 | packet_write_wait(); | ||
116 | return 1; | ||
117 | } | ||
118 | #endif /* KRB4 */ | ||
119 | |||
120 | #ifdef AFS | ||
121 | int auth_kerberos_tgt(struct passwd *pw, const char *string) | ||
122 | { | ||
123 | CREDENTIALS creds; | ||
124 | extern char *ticket; | ||
125 | int r; | ||
126 | |||
127 | if (!radix_to_creds(string, &creds)) { | ||
128 | log("Protocol error decoding Kerberos V4 tgt"); | ||
129 | packet_send_debug("Protocol error decoding Kerberos V4 tgt"); | ||
130 | goto auth_kerberos_tgt_failure; | ||
131 | } | ||
132 | if (strncmp(creds.service, "", 1) == 0) /* backward compatibility */ | ||
133 | strlcpy(creds.service, "krbtgt", sizeof creds.service); | ||
134 | |||
135 | if (strcmp(creds.service, "krbtgt")) { | ||
136 | log("Kerberos V4 tgt (%s%s%s@%s) rejected for uid %d", | ||
137 | creds.pname, creds.pinst[0] ? "." : "", creds.pinst, creds.realm, | ||
138 | pw->pw_uid); | ||
139 | packet_send_debug("Kerberos V4 tgt (%s%s%s@%s) rejected for uid %d", | ||
140 | creds.pname, creds.pinst[0] ? "." : "", creds.pinst, | ||
141 | creds.realm, pw->pw_uid); | ||
142 | goto auth_kerberos_tgt_failure; | ||
143 | } | ||
144 | if (!ssh_tf_init(pw->pw_uid) || | ||
145 | (r = in_tkt(creds.pname, creds.pinst)) || | ||
146 | (r = save_credentials(creds.service, creds.instance, creds.realm, | ||
147 | creds.session, creds.lifetime, creds.kvno, | ||
148 | &creds.ticket_st, creds.issue_date))) { | ||
149 | xfree(ticket); | ||
150 | ticket = NULL; | ||
151 | packet_send_debug("Kerberos V4 tgt refused: couldn't save credentials"); | ||
152 | goto auth_kerberos_tgt_failure; | ||
153 | } | ||
154 | /* Successful authentication, passed all checks. */ | ||
155 | chown(ticket, pw->pw_uid, pw->pw_gid); | ||
156 | packet_send_debug("Kerberos V4 tgt accepted (%s.%s@%s, %s%s%s@%s)", | ||
157 | creds.service, creds.instance, creds.realm, | ||
158 | creds.pname, creds.pinst[0] ? "." : "", | ||
159 | creds.pinst, creds.realm); | ||
160 | |||
161 | packet_start(SSH_SMSG_SUCCESS); | ||
162 | packet_send(); | ||
163 | packet_write_wait(); | ||
164 | return 1; | ||
165 | |||
166 | auth_kerberos_tgt_failure: | ||
167 | memset(&creds, 0, sizeof(creds)); | ||
168 | packet_start(SSH_SMSG_FAILURE); | ||
169 | packet_send(); | ||
170 | packet_write_wait(); | ||
171 | return 0; | ||
172 | } | ||
173 | |||
174 | int auth_afs_token(char *server_user, uid_t uid, const char *string) | ||
175 | { | ||
176 | CREDENTIALS creds; | ||
177 | |||
178 | if (!radix_to_creds(string, &creds)) { | ||
179 | log("Protocol error decoding AFS token"); | ||
180 | packet_send_debug("Protocol error decoding AFS token"); | ||
181 | packet_start(SSH_SMSG_FAILURE); | ||
182 | packet_send(); | ||
183 | packet_write_wait(); | ||
184 | return 0; | ||
185 | } | ||
186 | if (strncmp(creds.service, "", 1) == 0) /* backward compatibility */ | ||
187 | strlcpy(creds.service, "afs", sizeof creds.service); | ||
188 | |||
189 | if (strncmp(creds.pname, "AFS ID ", 7) == 0) | ||
190 | uid = atoi(creds.pname + 7); | ||
191 | |||
192 | if (kafs_settoken(creds.realm, uid, &creds)) { | ||
193 | log("AFS token (%s@%s) rejected for uid %d", creds.pname, | ||
194 | creds.realm, uid); | ||
195 | packet_send_debug("AFS token (%s@%s) rejected for uid %d", creds.pname, | ||
196 | creds.realm, uid); | ||
197 | packet_start(SSH_SMSG_FAILURE); | ||
198 | packet_send(); | ||
199 | packet_write_wait(); | ||
200 | return 0; | ||
201 | } | ||
202 | packet_send_debug("AFS token accepted (%s@%s, %s@%s)", creds.service, | ||
203 | creds.realm, creds.pname, creds.realm); | ||
204 | packet_start(SSH_SMSG_SUCCESS); | ||
205 | packet_send(); | ||
206 | packet_write_wait(); | ||
207 | return 1; | ||
208 | } | ||
209 | #endif /* AFS */ | ||