- djm@cvs.openbsd.org 2010/01/30 02:54:53

[openssh.git] / auth-krb5.c

diff --git a/auth-krb5.c b/auth-krb5.c
index 0aa5195b892f0a59cd92bd63990d3c868045272f..d019fe202c5ef8cf6670dffb44218253cf75bfec 100644 (file)
--- a/auth-krb5.c
+++ b/auth-krb5.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: auth-krb5.c,v 1.19 2006/08/03 03:34:41 deraadt Exp $ */
 /*
  *    Kerberos v5 authentication and ticket-passing routines.
  *
@@ -28,19 +29,27 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: auth-krb5.c,v 1.12 2003/08/28 12:54:34 markus Exp $");
 
+#include <sys/types.h>
+#include <pwd.h>
+#include <stdarg.h>
+
+#include "xmalloc.h"
 #include "ssh.h"
 #include "ssh1.h"
 #include "packet.h"
-#include "xmalloc.h"
 #include "log.h"
+#include "buffer.h"
 #include "servconf.h"
 #include "uidswap.h"
+#include "key.h"
+#include "hostfile.h"
 #include "auth.h"
 
 #ifdef KRB5
-
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
 #include <krb5.h>
 
 extern ServerOptions    options;
@@ -50,17 +59,11 @@ krb5_init(void *context)
 {
        Authctxt *authctxt = (Authctxt *)context;
        krb5_error_code problem;
-       static int cleanup_registered = 0;
 
        if (authctxt->krb5_ctx == NULL) {
                problem = krb5_init_context(&authctxt->krb5_ctx);
                if (problem)
                        return (problem);
-               krb5_init_ets(authctxt->krb5_ctx);
-       }
-       if (!cleanup_registered) {
-               fatal_add_cleanup(krb5_cleanup_proc, authctxt);
-               cleanup_registered = 1;
        }
        return (0);
 }
@@ -71,14 +74,15 @@ auth_krb5_password(Authctxt *authctxt, const char *password)
 #ifndef HEIMDAL
        krb5_creds creds;
        krb5_principal server;
-       char ccname[40];
-       int tmpfd;
-#endif 
+#endif
        krb5_error_code problem;
        krb5_ccache ccache = NULL;
+       int len;
+       char *client, *platform_client;
 
-       if (authctxt->pw == NULL)
-               return (0);
+       /* get platform-specific kerberos client principal name (if it exists) */
+       platform_client = platform_krb5_get_principal_name(authctxt->pw->pw_name);
+       client = platform_client ? platform_client : authctxt->pw->pw_name;
 
        temporarily_use_uid(authctxt->pw);
 
@@ -86,7 +90,7 @@ auth_krb5_password(Authctxt *authctxt, const char *password)
        if (problem)
                goto out;
 
-       problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
+       problem = krb5_parse_name(authctxt->krb5_ctx, client,
                    &authctxt->krb5_user);
        if (problem)
                goto out;
@@ -102,14 +106,15 @@ auth_krb5_password(Authctxt *authctxt, const char *password)
                goto out;
 
        restore_uid();
-       
+
        problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
            ccache, password, 1, NULL);
-       
+
        temporarily_use_uid(authctxt->pw);
 
        if (problem)
                goto out;
+
        problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops,
            &authctxt->krb5_fwd_ccache);
        if (problem)
@@ -140,30 +145,13 @@ auth_krb5_password(Authctxt *authctxt, const char *password)
        temporarily_use_uid(authctxt->pw);
        if (problem)
                goto out;
-       
-       if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, 
-                         authctxt->pw->pw_name)) {
-               problem = -1;
-               goto out;
-       } 
 
-       snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid());
-       
-       if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) {
-               logit("mkstemp(): %.100s", strerror(errno));
-               problem = errno;
-               goto out;
-       }
-       
-       if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
-               logit("fchmod(): %.100s", strerror(errno));
-               close(tmpfd);
-               problem = errno;
+       if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, client)) {
+               problem = -1;
                goto out;
        }
-       close(tmpfd);
 
-       problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &authctxt->krb5_fwd_ccache);
+       problem = ssh_krb5_cc_gen(authctxt->krb5_ctx, &authctxt->krb5_fwd_ccache);
        if (problem)
                goto out;
 
@@ -171,17 +159,30 @@ auth_krb5_password(Authctxt *authctxt, const char *password)
                                     authctxt->krb5_user);
        if (problem)
                goto out;
-                               
+
        problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
                                 &creds);
        if (problem)
                goto out;
-#endif         
+#endif
 
        authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
 
+       len = strlen(authctxt->krb5_ticket_file) + 6;
+       authctxt->krb5_ccname = xmalloc(len);
+       snprintf(authctxt->krb5_ccname, len, "FILE:%s",
+           authctxt->krb5_ticket_file);
+
+#ifdef USE_PAM
+       if (options.use_pam)
+               do_pam_putenv("KRB5CCNAME", authctxt->krb5_ccname);
+#endif
+
  out:
        restore_uid();
+       
+       if (platform_client != NULL)
+               xfree(platform_client);
 
        if (problem) {
                if (ccache)
@@ -201,14 +202,12 @@ auth_krb5_password(Authctxt *authctxt, const char *password)
                else
                        return (0);
        }
-       return (1);
+       return (authctxt->valid ? 1 : 0);
 }
 
 void
-krb5_cleanup_proc(void *context)
+krb5_cleanup_proc(Authctxt *authctxt)
 {
-       Authctxt *authctxt = (Authctxt *)context;
-
        debug("krb5_cleanup_proc called");
        if (authctxt->krb5_fwd_ccache) {
                krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
@@ -224,4 +223,34 @@ krb5_cleanup_proc(void *context)
        }
 }
 
+#ifndef HEIMDAL
+krb5_error_code
+ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
+       int tmpfd, ret;
+       char ccname[40];
+       mode_t old_umask;
+
+       ret = snprintf(ccname, sizeof(ccname),
+           "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());
+       if (ret < 0 || (size_t)ret >= sizeof(ccname))
+               return ENOMEM;
+
+       old_umask = umask(0177);
+       tmpfd = mkstemp(ccname + strlen("FILE:"));
+       umask(old_umask);
+       if (tmpfd == -1) {
+               logit("mkstemp(): %.100s", strerror(errno));
+               return errno;
+       }
+
+       if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
+               logit("fchmod(): %.100s", strerror(errno));
+               close(tmpfd);
+               return errno;
+       }
+       close(tmpfd);
+
+       return (krb5_cc_resolve(ctx, ccname, ccache));
+}
+#endif /* !HEIMDAL */
 #endif /* KRB5 */