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authorDamien Miller <djm@mindrot.org>1999-10-27 13:42:43 +1000
committerDamien Miller <djm@mindrot.org>1999-10-27 13:42:43 +1000
commitd4a8b7e34dd619a4debf9a206c81db26d1402ea6 (patch)
treea47d770a2f790f40d18b0982d4e55fa7cfb1fa3b /auth-krb4.c
Initial revision
Diffstat (limited to 'auth-krb4.c')
-rw-r--r--auth-krb4.c209
1 files changed, 209 insertions, 0 deletions
diff --git a/auth-krb4.c b/auth-krb4.c
new file mode 100644
index 00000000..720f3a4c
--- /dev/null
+++ b/auth-krb4.c
@@ -0,0 +1,209 @@
+/*
+
+ auth-kerberos.c
+
+ Dug Song <dugsong@UMICH.EDU>
+
+ Kerberos v4 authentication and ticket-passing routines.
+
+ $Id: auth-krb4.c,v 1.1 1999/10/27 03:42:43 damien Exp $
+*/
+
+#include "includes.h"
+#include "packet.h"
+#include "xmalloc.h"
+#include "ssh.h"
+
+#ifdef KRB4
+int ssh_tf_init(uid_t uid)
+{
+ extern char *ticket;
+ char *tkt_root = TKT_ROOT;
+ struct stat st;
+ int fd;
+
+ /* Set unique ticket string manually since we're still root. */
+ ticket = xmalloc(MAXPATHLEN);
+#ifdef AFS
+ if (lstat("/ticket", &st) != -1)
+ tkt_root = "/ticket/";
+#endif /* AFS */
+ snprintf(ticket, MAXPATHLEN, "%s%d_%d", tkt_root, uid, getpid());
+ (void) krb_set_tkt_string(ticket);
+
+ /* Make sure we own this ticket file, and we created it. */
+ if (lstat(ticket, &st) == -1 && errno == ENOENT) {
+ /* good, no ticket file exists. create it. */
+ if ((fd = open(ticket, O_RDWR|O_CREAT|O_EXCL, 0600)) != -1) {
+ close(fd);
+ return 1;
+ }
+ }
+ else {
+ /* file exists. make sure server_user owns it (e.g. just passed ticket),
+ and that it isn't a symlink, and that it is mode 600. */
+ if (st.st_mode == (S_IFREG|S_IRUSR|S_IWUSR) && st.st_uid == uid)
+ return 1;
+ }
+ /* Failure. */
+ log("WARNING: bad ticket file %s", ticket);
+ return 0;
+}
+
+int auth_krb4(const char *server_user, KTEXT auth, char **client)
+{
+ AUTH_DAT adat = { 0 };
+ KTEXT_ST reply;
+ char instance[INST_SZ];
+ int r, s;
+ u_int cksum;
+ Key_schedule schedule;
+ struct sockaddr_in local, foreign;
+
+ s = packet_get_connection_in();
+
+ r = sizeof(local);
+ memset(&local, 0, sizeof(local));
+ if (getsockname(s, (struct sockaddr *) &local, &r) < 0)
+ debug("getsockname failed: %.100s", strerror(errno));
+ r = sizeof(foreign);
+ memset(&foreign, 0, sizeof(foreign));
+ if (getpeername(s, (struct sockaddr *)&foreign, &r) < 0)
+ debug("getpeername failed: %.100s", strerror(errno));
+
+ instance[0] = '*'; instance[1] = 0;
+
+ /* Get the encrypted request, challenge, and session key. */
+ if ((r = krb_rd_req(auth, KRB4_SERVICE_NAME, instance, 0, &adat, ""))) {
+ packet_send_debug("Kerberos V4 krb_rd_req: %.100s", krb_err_txt[r]);
+ return 0;
+ }
+ des_key_sched((des_cblock *)adat.session, schedule);
+
+ *client = xmalloc(MAX_K_NAME_SZ);
+ (void) snprintf(*client, MAX_K_NAME_SZ, "%s%s%s@%s", adat.pname,
+ *adat.pinst ? "." : "", adat.pinst, adat.prealm);
+
+ /* Check ~/.klogin authorization now. */
+ if (kuserok(&adat, (char *)server_user) != KSUCCESS) {
+ packet_send_debug("Kerberos V4 .klogin authorization failed!");
+ log("Kerberos V4 .klogin authorization failed for %s to account %s",
+ *client, server_user);
+ return 0;
+ }
+ /* Increment the checksum, and return it encrypted with the session key. */
+ cksum = adat.checksum + 1;
+ cksum = htonl(cksum);
+
+ /* If we can't successfully encrypt the checksum, we send back an empty
+ message, admitting our failure. */
+ if ((r = krb_mk_priv((u_char *)&cksum, reply.dat, sizeof(cksum)+1,
+ schedule, &adat.session, &local, &foreign)) < 0) {
+ packet_send_debug("Kerberos V4 mk_priv: (%d) %s", r, krb_err_txt[r]);
+ reply.dat[0] = 0;
+ reply.length = 0;
+ }
+ else
+ reply.length = r;
+
+ /* Clear session key. */
+ memset(&adat.session, 0, sizeof(&adat.session));
+
+ packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE);
+ packet_put_string((char *) reply.dat, reply.length);
+ packet_send();
+ packet_write_wait();
+ return 1;
+}
+#endif /* KRB4 */
+
+#ifdef AFS
+int auth_kerberos_tgt(struct passwd *pw, const char *string)
+{
+ CREDENTIALS creds;
+ extern char *ticket;
+ int r;
+
+ if (!radix_to_creds(string, &creds)) {
+ log("Protocol error decoding Kerberos V4 tgt");
+ packet_send_debug("Protocol error decoding Kerberos V4 tgt");
+ goto auth_kerberos_tgt_failure;
+ }
+ if (strncmp(creds.service, "", 1) == 0) /* backward compatibility */
+ strlcpy(creds.service, "krbtgt", sizeof creds.service);
+
+ if (strcmp(creds.service, "krbtgt")) {
+ log("Kerberos V4 tgt (%s%s%s@%s) rejected for uid %d",
+ creds.pname, creds.pinst[0] ? "." : "", creds.pinst, creds.realm,
+ pw->pw_uid);
+ packet_send_debug("Kerberos V4 tgt (%s%s%s@%s) rejected for uid %d",
+ creds.pname, creds.pinst[0] ? "." : "", creds.pinst,
+ creds.realm, pw->pw_uid);
+ goto auth_kerberos_tgt_failure;
+ }
+ if (!ssh_tf_init(pw->pw_uid) ||
+ (r = in_tkt(creds.pname, creds.pinst)) ||
+ (r = save_credentials(creds.service, creds.instance, creds.realm,
+ creds.session, creds.lifetime, creds.kvno,
+ &creds.ticket_st, creds.issue_date))) {
+ xfree(ticket);
+ ticket = NULL;
+ packet_send_debug("Kerberos V4 tgt refused: couldn't save credentials");
+ goto auth_kerberos_tgt_failure;
+ }
+ /* Successful authentication, passed all checks. */
+ chown(ticket, pw->pw_uid, pw->pw_gid);
+ packet_send_debug("Kerberos V4 tgt accepted (%s.%s@%s, %s%s%s@%s)",
+ creds.service, creds.instance, creds.realm,
+ creds.pname, creds.pinst[0] ? "." : "",
+ creds.pinst, creds.realm);
+
+ packet_start(SSH_SMSG_SUCCESS);
+ packet_send();
+ packet_write_wait();
+ return 1;
+
+auth_kerberos_tgt_failure:
+ memset(&creds, 0, sizeof(creds));
+ packet_start(SSH_SMSG_FAILURE);
+ packet_send();
+ packet_write_wait();
+ return 0;
+}
+
+int auth_afs_token(char *server_user, uid_t uid, const char *string)
+{
+ CREDENTIALS creds;
+
+ if (!radix_to_creds(string, &creds)) {
+ log("Protocol error decoding AFS token");
+ packet_send_debug("Protocol error decoding AFS token");
+ packet_start(SSH_SMSG_FAILURE);
+ packet_send();
+ packet_write_wait();
+ return 0;
+ }
+ if (strncmp(creds.service, "", 1) == 0) /* backward compatibility */
+ strlcpy(creds.service, "afs", sizeof creds.service);
+
+ if (strncmp(creds.pname, "AFS ID ", 7) == 0)
+ uid = atoi(creds.pname + 7);
+
+ if (kafs_settoken(creds.realm, uid, &creds)) {
+ log("AFS token (%s@%s) rejected for uid %d", creds.pname,
+ creds.realm, uid);
+ packet_send_debug("AFS token (%s@%s) rejected for uid %d", creds.pname,
+ creds.realm, uid);
+ packet_start(SSH_SMSG_FAILURE);
+ packet_send();
+ packet_write_wait();
+ return 0;
+ }
+ packet_send_debug("AFS token accepted (%s@%s, %s@%s)", creds.service,
+ creds.realm, creds.pname, creds.realm);
+ packet_start(SSH_SMSG_SUCCESS);
+ packet_send();
+ packet_write_wait();
+ return 1;
+}
+#endif /* AFS */