1 files changed, 259 insertions, 0 deletions

diff --git a/auth-krb5.c b/auth-krb5.c
new file mode 100644
index 000000000..08c917459
--- /dev/null
+++ b/auth-krb5.c
@@ -0,0 +1,259 @@
+/*
+ *    Kerberos v5 authentication and ticket-passing routines.
+ * 
+ * $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $
+ * $OpenBSD: auth-krb5.c,v 1.1 2001/06/26 16:15:23 dugsong Exp $
+ */
+
+#include "includes.h"
+#include "ssh.h"
+#include "ssh1.h"
+#include "packet.h"
+#include "xmalloc.h"
+#include "log.h"
+#include "servconf.h"
+#include "uidswap.h"
+#include "auth.h"
+
+#ifdef KRB5
+#include <krb5.h>
+
+extern ServerOptions     options;
+
+static int
+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);
+}
+
+/*
+ * 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_error_code problem;
+        krb5_principal server;
+        krb5_data reply;
+        krb5_ticket *ticket;
+        int fd;
+        
+        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();
+        problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
+            authctxt->krb5_auth_ctx, &fd);
+        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;
+        
+        problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
+            &authctxt->krb5_user);
+        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);
+        
+        packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE);
+        packet_put_string((char *) reply.data, reply.length);
+        packet_send();
+        packet_write_wait();
+        
+ err:
+        if (server)
+                krb5_free_principal(authctxt->krb5_ctx, server);
+        if (ticket)
+                krb5_free_ticket(authctxt->krb5_ctx, ticket);
+        if (reply.length)
+                xfree(reply.data);
+        
+        if (problem) {
+                debug("Kerberos v5 authentication failed: %s",
+                    krb5_get_err_text(authctxt->krb5_ctx, problem));
+                return (0);
+        }
+        return (1);
+}
+
+int
+auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt)
+{
+        krb5_error_code problem;
+        krb5_ccache ccache = NULL;
+        char *pname;
+        
+        if (authctxt->pw == NULL || authctxt->krb5_user == NULL)
+                return (0);
+        
+        temporarily_use_uid(authctxt->pw);
+        
+        problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
+        if (problem)
+                goto fail;
+        
+        problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
+            authctxt->krb5_user);
+        if (problem)
+                goto fail;
+        
+        problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
+            ccache, tgt);
+        if (problem)
+                goto fail;
+        
+        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);
+}
+
+int
+auth_krb5_password(Authctxt *authctxt, const char *password)
+{
+        krb5_error_code problem;
+        
+        if (authctxt->pw == NULL)
+                return (0);
+        
+        temporarily_use_uid(authctxt->pw);
+        
+        problem = krb5_init(authctxt);
+        if (problem)
+                goto out;
+        
+        problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
+                    &authctxt->krb5_user);
+        if (problem)
+                goto out;
+        
+        problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops,
+            &authctxt->krb5_fwd_ccache);
+        if (problem)
+                goto out;
+        
+        problem = krb5_cc_initialize(authctxt->krb5_ctx,
+            authctxt->krb5_fwd_ccache, authctxt->krb5_user);
+        if (problem)
+                goto out;
+        
+        problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
+            authctxt->krb5_fwd_ccache, password, 1, NULL);
+        if (problem)
+                goto out;
+        
+        authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
+        
+ out:
+        restore_uid();
+        
+        if (problem) {
+                debug("Kerberos password authentication failed: %s",
+                    krb5_get_err_text(authctxt->krb5_ctx, problem));
+                
+                krb5_cleanup_proc(authctxt);
+                
+                if (options.kerberos_or_local_passwd)
+                        return (-1);
+                else
+                        return (0);
+        }
+        return (1);
+}
+
+void
+krb5_cleanup_proc(void *context)
+{
+        Authctxt *authctxt = (Authctxt *)context;
+        
+        debug("krb5_cleanup_proc called");
+        if (authctxt->krb5_fwd_ccache) {
+                krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
+                authctxt->krb5_fwd_ccache = NULL;
+        }
+        if (authctxt->krb5_user) {
+                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;
+        }
+}
+
+#endif /* KRB5 */