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/*
* 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 1.4 2002/01/27 15:12:09 markus 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, 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();
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();
ret = 1;
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 (ret);
}
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;
restore_uid();
problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
authctxt->krb5_fwd_ccache, password, 1, NULL);
temporarily_use_uid(authctxt->pw);
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 */
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