+/* $OpenBSD: auth-krb5.c,v 1.18 2006/05/06 08:35:40 dtucker Exp $ */
/*
* Kerberos v5 authentication and ticket-passing routines.
*
*/
#include "includes.h"
-RCSID("$OpenBSD: auth-krb5.c,v 1.11 2003/07/16 15:02:06 markus Exp $");
#include "ssh.h"
#include "ssh1.h"
#include "auth.h"
#ifdef KRB5
-
#include <krb5.h>
-#ifndef HEIMDAL
-#define krb5_get_err_text(context,code) error_message(code)
-#endif /* !HEIMDAL */
extern ServerOptions options;
{
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);
-}
-
-/*
- * Try krb5 authentication. server_user is passed for logging purposes
- * only, in auth is received ticket, in client is returned principal
- * from the ticket
- */
-int
-auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *reply)
-{
- krb5_error_code problem;
- krb5_principal server;
- krb5_ticket *ticket;
- int fd, ret;
-
- ret = 0;
- server = NULL;
- ticket = NULL;
- reply->length = 0;
-
- problem = krb5_init(authctxt);
- if (problem)
- goto err;
-
- problem = krb5_auth_con_init(authctxt->krb5_ctx,
- &authctxt->krb5_auth_ctx);
- if (problem)
- goto err;
-
- fd = packet_get_connection_in();
-#ifdef HEIMDAL
- problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
- authctxt->krb5_auth_ctx, &fd);
-#else
- problem = krb5_auth_con_genaddrs(authctxt->krb5_ctx,
- authctxt->krb5_auth_ctx,fd,
- KRB5_AUTH_CONTEXT_GENERATE_REMOTE_FULL_ADDR |
- KRB5_AUTH_CONTEXT_GENERATE_LOCAL_FULL_ADDR);
-#endif
- if (problem)
- goto err;
-
- problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL,
- KRB5_NT_SRV_HST, &server);
- if (problem)
- goto err;
-
- problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx,
- auth, server, NULL, NULL, &ticket);
- if (problem)
- goto err;
-
-#ifdef HEIMDAL
- problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
- &authctxt->krb5_user);
-#else
- problem = krb5_copy_principal(authctxt->krb5_ctx,
- ticket->enc_part2->client,
- &authctxt->krb5_user);
-#endif
- if (problem)
- goto err;
-
- /* if client wants mutual auth */
- problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
- reply);
- if (problem)
- goto err;
-
- /* Check .k5login authorization now. */
- if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
- authctxt->pw->pw_name))
- goto err;
-
- if (client)
- krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
- client);
-
- ret = 1;
- err:
- if (server)
- krb5_free_principal(authctxt->krb5_ctx, server);
- if (ticket)
- krb5_free_ticket(authctxt->krb5_ctx, ticket);
- if (!ret && reply->length) {
- xfree(reply->data);
- memset(reply, 0, sizeof(*reply));
- }
-
- if (problem) {
- if (authctxt->krb5_ctx != NULL)
- debug("Kerberos v5 authentication failed: %s",
- krb5_get_err_text(authctxt->krb5_ctx, problem));
- else
- debug("Kerberos v5 authentication failed: %d",
- problem);
- }
-
- return (ret);
-}
-
-int
-auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt)
-{
- krb5_error_code problem;
- krb5_ccache ccache = NULL;
- char *pname;
- krb5_creds **creds;
-
- if (authctxt->pw == NULL || authctxt->krb5_user == NULL)
- return (0);
-
- temporarily_use_uid(authctxt->pw);
-
-#ifdef HEIMDAL
- problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
-#else
-{
- char ccname[40];
- int tmpfd;
-
- 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 fail;
- }
- if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
- logit("fchmod(): %.100s", strerror(errno));
- close(tmpfd);
- problem = errno;
- goto fail;
}
- close(tmpfd);
- problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &ccache);
-}
-#endif
- if (problem)
- goto fail;
-
- problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
- authctxt->krb5_user);
- if (problem)
- goto fail;
-
-#ifdef HEIMDAL
- problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
- ccache, tgt);
- if (problem)
- goto fail;
-#else
- problem = krb5_rd_cred(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
- tgt, &creds, NULL);
- if (problem)
- goto fail;
- problem = krb5_cc_store_cred(authctxt->krb5_ctx, ccache, *creds);
- if (problem)
- goto fail;
-#endif
-
- authctxt->krb5_fwd_ccache = ccache;
- ccache = NULL;
-
- authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
-
- problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
- &pname);
- if (problem)
- goto fail;
-
- debug("Kerberos v5 TGT accepted (%s)", pname);
-
- restore_uid();
-
- return (1);
-
- fail:
- if (problem)
- debug("Kerberos v5 TGT passing failed: %s",
- krb5_get_err_text(authctxt->krb5_ctx, problem));
- if (ccache)
- krb5_cc_destroy(authctxt->krb5_ctx, ccache);
-
- restore_uid();
-
return (0);
}
#ifndef HEIMDAL
krb5_creds creds;
krb5_principal server;
- char ccname[40];
- int tmpfd;
-#endif
+#endif
krb5_error_code problem;
krb5_ccache ccache = NULL;
-
- if (authctxt->pw == NULL)
- return (0);
+ int len;
temporarily_use_uid(authctxt->pw);
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)
temporarily_use_uid(authctxt->pw);
if (problem)
goto out;
-
- if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
+
+ 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;
- 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;
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();
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);
krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
authctxt->krb5_user = NULL;
}
- if (authctxt->krb5_auth_ctx) {
- krb5_auth_con_free(authctxt->krb5_ctx,
- authctxt->krb5_auth_ctx);
- authctxt->krb5_auth_ctx = NULL;
- }
if (authctxt->krb5_ctx) {
krb5_free_context(authctxt->krb5_ctx);
authctxt->krb5_ctx = NULL;
}
}
+#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 */