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authorBen Lindstrom <mouring@eviladmin.org>2001-07-04 04:21:14 +0000
committerBen Lindstrom <mouring@eviladmin.org>2001-07-04 04:21:14 +0000
commitec95ed9b4ca014643a0272f6fa5b24ac9c70d263 (patch)
tree91a5c1b319337e52f7cc80742eda081f6dbfd6c2 /auth-krb4.c
parentb4c774cf8878d9100fde92ff4e938671c3b0301b (diff)
- dugsong@cvs.openbsd.org 2001/06/26 16:15:25
[auth1.c auth.h auth-krb4.c auth-passwd.c readconf.c readconf.h servconf.c servconf.h session.c sshconnect1.c sshd.c] Kerberos v5 support for SSH1, mostly from Assar Westerlund <assar@freebsd.org> and Bjorn Gronvall <bg@sics.se>. markus@ ok
Diffstat (limited to 'auth-krb4.c')
-rw-r--r--auth-krb4.c362
1 files changed, 172 insertions, 190 deletions
diff --git a/auth-krb4.c b/auth-krb4.c
index 8bb6e3d6..031dcd30 100644
--- a/auth-krb4.c
+++ b/auth-krb4.c
@@ -23,7 +23,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: auth-krb4.c,v 1.23 2001/01/22 08:15:00 markus Exp $");
+RCSID("$OpenBSD: auth-krb4.c,v 1.24 2001/06/26 16:15:22 dugsong Exp $");
#include "ssh.h"
#include "ssh1.h"
@@ -31,6 +31,7 @@ RCSID("$OpenBSD: auth-krb4.c,v 1.23 2001/01/22 08:15:00 markus Exp $");
#include "xmalloc.h"
#include "log.h"
#include "servconf.h"
+#include "uidswap.h"
#include "auth.h"
#ifdef AFS
@@ -38,70 +39,114 @@ RCSID("$OpenBSD: auth-krb4.c,v 1.23 2001/01/22 08:15:00 markus Exp $");
#endif
#ifdef KRB4
-char *ticket = NULL;
-
extern ServerOptions options;
+static int
+krb4_init(void *context)
+{
+ static int cleanup_registered = 0;
+ Authctxt *authctxt = (Authctxt *)context;
+ const char *tkt_root = TKT_ROOT;
+ struct stat st;
+ int fd;
+
+ if (!authctxt->krb4_ticket_file) {
+ /* Set unique ticket string manually since we're still root. */
+ authctxt->krb4_ticket_file = xmalloc(MAXPATHLEN);
+#ifdef AFS
+ if (lstat("/ticket", &st) != -1)
+ tkt_root = "/ticket/";
+#endif /* AFS */
+ snprintf(authctxt->krb4_ticket_file, MAXPATHLEN, "%s%u_%d",
+ tkt_root, authctxt->pw->pw_uid, getpid());
+ krb_set_tkt_string(authctxt->krb4_ticket_file);
+ }
+ /* Register ticket cleanup in case of fatal error. */
+ if (!cleanup_registered) {
+ fatal_add_cleanup(krb4_cleanup_proc, authctxt);
+ cleanup_registered = 1;
+ }
+ /* Try to create our ticket file. */
+ if ((fd = mkstemp(authctxt->krb4_ticket_file)) != -1) {
+ close(fd);
+ return (1);
+ }
+ /* Ticket file exists - make sure user owns it (just passed ticket). */
+ if (lstat(authctxt->krb4_ticket_file, &st) != -1) {
+ if (st.st_mode == (S_IFREG | S_IRUSR | S_IWUSR) &&
+ st.st_uid == authctxt->pw->pw_uid)
+ return (1);
+ }
+ /* Failure - cancel cleanup function, leaving ticket for inspection. */
+ log("WARNING: bad ticket file %s", authctxt->krb4_ticket_file);
+
+ fatal_remove_cleanup(krb4_cleanup_proc, authctxt);
+ cleanup_registered = 0;
+
+ xfree(authctxt->krb4_ticket_file);
+ authctxt->krb4_ticket_file = NULL;
+
+ return (0);
+}
+
/*
* try krb4 authentication,
* return 1 on success, 0 on failure, -1 if krb4 is not available
*/
-
int
-auth_krb4_password(struct passwd * pw, const char *password)
+auth_krb4_password(Authctxt *authctxt, const char *password)
{
AUTH_DAT adata;
KTEXT_ST tkt;
struct hostent *hp;
- u_long faddr;
- char localhost[MAXHOSTNAMELEN];
- char phost[INST_SZ];
- char realm[REALM_SZ];
+ struct passwd *pw;
+ char localhost[MAXHOSTNAMELEN], phost[INST_SZ], realm[REALM_SZ];
+ u_int32_t faddr;
int r;
-
+
+ if ((pw = authctxt->pw) == NULL)
+ return (0);
+
/*
* Try Kerberos password authentication only for non-root
* users and only if Kerberos is installed.
*/
if (pw->pw_uid != 0 && krb_get_lrealm(realm, 1) == KSUCCESS) {
-
/* Set up our ticket file. */
- if (!krb4_init(pw->pw_uid)) {
+ if (!krb4_init(authctxt)) {
log("Couldn't initialize Kerberos ticket file for %s!",
pw->pw_name);
- goto kerberos_auth_failure;
+ goto failure;
}
/* Try to get TGT using our password. */
- r = krb_get_pw_in_tkt((char *) pw->pw_name, "",
- realm, "krbtgt", realm,
- DEFAULT_TKT_LIFE, (char *) password);
+ r = krb_get_pw_in_tkt((char *) pw->pw_name, "", realm,
+ "krbtgt", realm, DEFAULT_TKT_LIFE, (char *)password);
if (r != INTK_OK) {
- packet_send_debug("Kerberos V4 password "
- "authentication for %s failed: %s",
- pw->pw_name, krb_err_txt[r]);
- goto kerberos_auth_failure;
+ debug("Kerberos v4 password authentication for %s "
+ "failed: %s", pw->pw_name, krb_err_txt[r]);
+ goto failure;
}
/* Successful authentication. */
chown(tkt_string(), pw->pw_uid, pw->pw_gid);
-
+
/*
* Now that we have a TGT, try to get a local
* "rcmd" ticket to ensure that we are not talking
* to a bogus Kerberos server.
*/
- (void) gethostname(localhost, sizeof(localhost));
- (void) strlcpy(phost, (char *) krb_get_phost(localhost),
- INST_SZ);
+ gethostname(localhost, sizeof(localhost));
+ strlcpy(phost, (char *)krb_get_phost(localhost),
+ sizeof(phost));
r = krb_mk_req(&tkt, KRB4_SERVICE_NAME, phost, realm, 33);
-
+
if (r == KSUCCESS) {
- if (!(hp = gethostbyname(localhost))) {
+ if ((hp = gethostbyname(localhost)) == NULL) {
log("Couldn't get local host address!");
- goto kerberos_auth_failure;
+ goto failure;
}
- memmove((void *) &faddr, (void *) hp->h_addr,
+ memmove((void *)&faddr, (void *)hp->h_addr,
sizeof(faddr));
-
+
/* Verify our "rcmd" ticket. */
r = krb_rd_req(&tkt, KRB4_SERVICE_NAME, phost,
faddr, &adata, "");
@@ -110,119 +155,74 @@ auth_krb4_password(struct passwd * pw, const char *password)
* Probably didn't have a srvtab on
* localhost. Disallow login.
*/
- log("Kerberos V4 TGT for %s unverifiable, "
+ log("Kerberos v4 TGT for %s unverifiable, "
"no srvtab installed? krb_rd_req: %s",
pw->pw_name, krb_err_txt[r]);
- goto kerberos_auth_failure;
+ goto failure;
} else if (r != KSUCCESS) {
- log("Kerberos V4 %s ticket unverifiable: %s",
+ log("Kerberos v4 %s ticket unverifiable: %s",
KRB4_SERVICE_NAME, krb_err_txt[r]);
- goto kerberos_auth_failure;
+ goto failure;
}
} else if (r == KDC_PR_UNKNOWN) {
/*
* Disallow login if no rcmd service exists, and
* log the error.
*/
- log("Kerberos V4 TGT for %s unverifiable: %s; %s.%s "
+ log("Kerberos v4 TGT for %s unverifiable: %s; %s.%s "
"not registered, or srvtab is wrong?", pw->pw_name,
- krb_err_txt[r], KRB4_SERVICE_NAME, phost);
- goto kerberos_auth_failure;
+ krb_err_txt[r], KRB4_SERVICE_NAME, phost);
+ goto failure;
} else {
/*
* TGT is bad, forget it. Possibly spoofed!
*/
- packet_send_debug("WARNING: Kerberos V4 TGT "
- "possibly spoofed for %s: %s",
- pw->pw_name, krb_err_txt[r]);
- goto kerberos_auth_failure;
+ debug("WARNING: Kerberos v4 TGT possibly spoofed "
+ "for %s: %s", pw->pw_name, krb_err_txt[r]);
+ goto failure;
}
-
/* Authentication succeeded. */
- return 1;
-
-kerberos_auth_failure:
- krb4_cleanup_proc(NULL);
-
- if (!options.kerberos_or_local_passwd)
- return 0;
- } else {
+ return (1);
+ } else
/* Logging in as root or no local Kerberos realm. */
- packet_send_debug("Unable to authenticate to Kerberos.");
- }
+ debug("Unable to authenticate to Kerberos.");
+
+ failure:
+ krb4_cleanup_proc(authctxt);
+
+ if (!options.kerberos_or_local_passwd)
+ return (0);
+
/* Fall back to ordinary passwd authentication. */
- return -1;
+ return (-1);
}
void
-krb4_cleanup_proc(void *ignore)
+krb4_cleanup_proc(void *context)
{
+ Authctxt *authctxt = (Authctxt *)context;
debug("krb4_cleanup_proc called");
- if (ticket) {
+ if (authctxt->krb4_ticket_file) {
(void) dest_tkt();
- xfree(ticket);
- ticket = NULL;
- }
-}
-
-int
-krb4_init(uid_t uid)
-{
- static int cleanup_registered = 0;
- const char *tkt_root = TKT_ROOT;
- struct stat st;
- int fd;
-
- if (!ticket) {
- /* 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%u_%d", tkt_root, uid, getpid());
- (void) krb_set_tkt_string(ticket);
- }
- /* Register ticket cleanup in case of fatal error. */
- if (!cleanup_registered) {
- fatal_add_cleanup(krb4_cleanup_proc, NULL);
- cleanup_registered = 1;
- }
- /* Try to create our ticket file. */
- if ((fd = mkstemp(ticket)) != -1) {
- close(fd);
- return 1;
- }
- /* Ticket file exists - make sure user owns it (just passed ticket). */
- if (lstat(ticket, &st) != -1) {
- if (st.st_mode == (S_IFREG | S_IRUSR | S_IWUSR) &&
- st.st_uid == uid)
- return 1;
+ xfree(authctxt->krb4_ticket_file);
+ authctxt->krb4_ticket_file = NULL;
}
- /* Failure - cancel cleanup function, leaving bad ticket for inspection. */
- log("WARNING: bad ticket file %s", ticket);
- fatal_remove_cleanup(krb4_cleanup_proc, NULL);
- cleanup_registered = 0;
- xfree(ticket);
- ticket = NULL;
-
- return 0;
}
int
-auth_krb4(const char *server_user, KTEXT auth, char **client)
+auth_krb4(Authctxt *authctxt, KTEXT auth, char **client)
{
AUTH_DAT adat = {0};
KTEXT_ST reply;
+ Key_schedule schedule;
+ struct sockaddr_in local, foreign;
char instance[INST_SZ];
- int r, s;
socklen_t slen;
u_int cksum;
- Key_schedule schedule;
- struct sockaddr_in local, foreign;
-
+ int r, s;
+
s = packet_get_connection_in();
-
+
slen = sizeof(local);
memset(&local, 0, sizeof(local));
if (getsockname(s, (struct sockaddr *) & local, &slen) < 0)
@@ -235,157 +235,139 @@ auth_krb4(const char *server_user, KTEXT auth, char **client)
}
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;
+ if ((r = krb_rd_req(auth, KRB4_SERVICE_NAME, instance,
+ 0, &adat, ""))) {
+ 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);
+ if (kuserok(&adat, authctxt->user) != KSUCCESS) {
+ log("Kerberos v4 .klogin authorization failed for %s to "
+ "account %s", *client, authctxt->user);
xfree(*client);
- return 0;
+ 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]);
+ 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;
+ return (1);
}
#endif /* KRB4 */
#ifdef AFS
int
-auth_kerberos_tgt(struct passwd *pw, const char *string)
+auth_krb4_tgt(Authctxt *authctxt, const char *string)
{
CREDENTIALS creds;
-
- if (pw == NULL)
- goto auth_kerberos_tgt_failure;
+ struct passwd *pw;
+
+ if ((pw = authctxt->pw) == NULL)
+ goto failure;
+
+ temporarily_use_uid(pw);
+
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;
+ log("Protocol error decoding Kerberos v4 TGT");
+ goto 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 %s", creds.pname,
- creds.pinst[0] ? "." : "", creds.pinst, creds.realm,
- pw->pw_name);
- packet_send_debug("Kerberos V4 tgt (%s%s%s@%s) rejected for %s",
+ log("Kerberos v4 TGT (%s%s%s@%s) rejected for %s",
creds.pname, creds.pinst[0] ? "." : "", creds.pinst,
creds.realm, pw->pw_name);
- goto auth_kerberos_tgt_failure;
+ goto failure;
}
- if (!krb4_init(pw->pw_uid))
- goto auth_kerberos_tgt_failure;
-
+ if (!krb4_init(authctxt))
+ goto failure;
+
if (in_tkt(creds.pname, creds.pinst) != KSUCCESS)
- goto auth_kerberos_tgt_failure;
-
+ goto failure;
+
if (save_credentials(creds.service, creds.instance, creds.realm,
- creds.session, creds.lifetime, creds.kvno,
- &creds.ticket_st, creds.issue_date) != KSUCCESS) {
- packet_send_debug("Kerberos V4 tgt refused: couldn't save credentials");
- goto auth_kerberos_tgt_failure;
+ creds.session, creds.lifetime, creds.kvno, &creds.ticket_st,
+ creds.issue_date) != KSUCCESS) {
+ debug("Kerberos v4 TGT refused: couldn't save credentials");
+ goto failure;
}
/* Successful authentication, passed all checks. */
chown(tkt_string(), 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);
+
+ debug("Kerberos v4 TGT accepted (%s%s%s@%s)",
+ creds.pname, creds.pinst[0] ? "." : "", creds.pinst, creds.realm);
memset(&creds, 0, sizeof(creds));
- packet_start(SSH_SMSG_SUCCESS);
- packet_send();
- packet_write_wait();
- return 1;
-
-auth_kerberos_tgt_failure:
- krb4_cleanup_proc(NULL);
+
+ restore_uid();
+
+ return (1);
+
+ failure:
+ krb4_cleanup_proc(authctxt);
memset(&creds, 0, sizeof(creds));
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
- return 0;
+ restore_uid();
+
+ return (0);
}
int
-auth_afs_token(struct passwd *pw, const char *token_string)
+auth_afs_token(Authctxt *authctxt, const char *token_string)
{
CREDENTIALS creds;
+ struct passwd *pw;
uid_t uid;
-
- if (pw == NULL) {
- /* XXX fake protocol error */
- packet_send_debug("Protocol error decoding AFS token");
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
- return 0;
- }
+
+ if ((pw = authctxt->pw) == NULL)
+ return (0);
+
if (!radix_to_creds(token_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;
+ 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);
else
uid = pw->pw_uid;
-
+
if (kafs_settoken(creds.realm, uid, &creds)) {
- log("AFS token (%s@%s) rejected for %s", creds.pname, creds.realm,
- pw->pw_name);
- packet_send_debug("AFS token (%s@%s) rejected for %s", creds.pname,
- creds.realm, pw->pw_name);
+ log("AFS token (%s@%s) rejected for %s",
+ creds.pname, creds.realm, pw->pw_name);
memset(&creds, 0, sizeof(creds));
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
- return 0;
+ return (0);
}
- packet_send_debug("AFS token accepted (%s@%s, %s@%s)", creds.service,
- creds.realm, creds.pname, creds.realm);
+ debug("AFS token accepted (%s@%s)", creds.pname, creds.realm);
memset(&creds, 0, sizeof(creds));
- packet_start(SSH_SMSG_SUCCESS);
- packet_send();
- packet_write_wait();
- return 1;
+
+ return (1);
}
#endif /* AFS */