]> andersk Git - openssh.git/blobdiff - auth-krb4.c
- (djm) Fix AIX limits from Alexandre Oliva <oliva@lsd.ic.unicamp.br>
[openssh.git] / auth-krb4.c
index 9f99533b19b036aaa1242f7a645a32d1e50f26e7..e32089b74379a7edfebdd31b87c6a9dcd8e75d04 100644 (file)
 #include "packet.h"
 #include "xmalloc.h"
 #include "ssh.h"
+#include "servconf.h"
+
+RCSID("$OpenBSD: auth-krb4.c,v 1.15 2000/06/22 23:54:59 djm Exp $");
 
 #ifdef KRB4
 char *ticket = NULL;
 
+extern ServerOptions options;
+
+/*
+ * 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_DAT adata;
+       KTEXT_ST tkt;
+       struct hostent *hp;
+       unsigned long faddr;
+       char localhost[MAXHOSTNAMELEN];
+       char phost[INST_SZ];
+       char realm[REALM_SZ];
+       int r;
+
+       /*
+        * 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)) {
+                       log("Couldn't initialize Kerberos ticket file for %s!",
+                           pw->pw_name);
+                       goto kerberos_auth_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);
+               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;
+               }
+               /* 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);
+               r = krb_mk_req(&tkt, KRB4_SERVICE_NAME, phost, realm, 33);
+
+               if (r == KSUCCESS) {
+                       if (!(hp = gethostbyname(localhost))) {
+                               log("Couldn't get local host address!");
+                               goto kerberos_auth_failure;
+                       }
+                       memmove((void *) &faddr, (void *) hp->h_addr,
+                           sizeof(faddr));
+
+                       /* Verify our "rcmd" ticket. */
+                       r = krb_rd_req(&tkt, KRB4_SERVICE_NAME, phost,
+                           faddr, &adata, "");
+                       if (r == RD_AP_UNDEC) {
+                               /*
+                                * Probably didn't have a srvtab on
+                                * localhost. Allow login.
+                                */
+                               log("Kerberos V4 TGT for %s unverifiable, "
+                                   "no srvtab installed? krb_rd_req: %s",
+                                   pw->pw_name, krb_err_txt[r]);
+                       } else if (r != KSUCCESS) {
+                               log("Kerberos V4 %s ticket unverifiable: %s",
+                                   KRB4_SERVICE_NAME, krb_err_txt[r]);
+                               goto kerberos_auth_failure;
+                       }
+               } else if (r == KDC_PR_UNKNOWN) {
+                       /*
+                        * Allow login if no rcmd service exists, but
+                        * log the error.
+                        */
+                       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);
+               } 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;
+               }
+
+               /* Authentication succeeded. */
+               return 1;
+
+kerberos_auth_failure:
+               krb4_cleanup_proc(NULL);
+
+               if (!options.kerberos_or_local_passwd)
+                       return 0;
+       } else {
+               /* Logging in as root or no local Kerberos realm. */
+               packet_send_debug("Unable to authenticate to Kerberos.");
+       }
+       /* Fall back to ordinary passwd authentication. */
+       return -1;
+}
+
 void
 krb4_cleanup_proc(void *ignore)
 {
@@ -22,11 +137,11 @@ krb4_cleanup_proc(void *ignore)
        }
 }
 
-int 
+int
 krb4_init(uid_t uid)
 {
        static int cleanup_registered = 0;
-       char *tkt_root = TKT_ROOT;
+       const char *tkt_root = TKT_ROOT;
        struct stat st;
        int fd;
 
@@ -66,26 +181,27 @@ krb4_init(uid_t uid)
        return 0;
 }
 
-int 
+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;
+       socklen_t slen;
        u_int cksum;
        Key_schedule schedule;
        struct sockaddr_in local, foreign;
 
        s = packet_get_connection_in();
 
-       r = sizeof(local);
+       slen = sizeof(local);
        memset(&local, 0, sizeof(local));
-       if (getsockname(s, (struct sockaddr *) & local, &r) < 0)
+       if (getsockname(s, (struct sockaddr *) & local, &slen) < 0)
                debug("getsockname failed: %.100s", strerror(errno));
-       r = sizeof(foreign);
+       slen = sizeof(foreign);
        memset(&foreign, 0, sizeof(foreign));
-       if (getpeername(s, (struct sockaddr *) & foreign, &r) < 0) {
+       if (getpeername(s, (struct sockaddr *) & foreign, &slen) < 0) {
                debug("getpeername failed: %.100s", strerror(errno));
                fatal_cleanup();
        }
@@ -138,7 +254,7 @@ auth_krb4(const char *server_user, KTEXT auth, char **client)
 #endif /* KRB4 */
 
 #ifdef AFS
-int 
+int
 auth_kerberos_tgt(struct passwd *pw, const char *string)
 {
        CREDENTIALS creds;
@@ -193,7 +309,7 @@ auth_kerberos_tgt_failure:
        return 0;
 }
 
-int 
+int
 auth_afs_token(struct passwd *pw, const char *token_string)
 {
        CREDENTIALS creds;
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