godot/thirdparty/openssl/ssl/kssl.c

/* ssl/kssl.c */
/*
 * Written by Vern Staats <[email protected]> for the OpenSSL project
 * 2000.
 */
/* ====================================================================
 * Copyright (c) 2000-2018 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    [email protected].
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * ([email protected]).  This product includes software written by Tim
 * Hudson ([email protected]).
 *
 */

/*-
 * ssl/kssl.c  --  Routines to support (& debug) Kerberos5 auth for openssl
 *
 *  19990701    VRS     Started.
 *  200011??    Jeffrey Altman, Richard Levitte
 *                      Generalized for Heimdal, Newer MIT, & Win32.
 *                      Integrated into main OpenSSL 0.9.7 snapshots.
 *  20010413    Simon Wilkinson, VRS
 *                      Real RFC2712 KerberosWrapper replaces AP_REQ.
 */

#include <openssl/opensslconf.h>

#include <string.h>

#define KRB5_PRIVATE    1

#include <openssl/ssl.h>
#include <openssl/evp.h>
#include <openssl/objects.h>
#include <openssl/krb5_asn.h>
#include "o_time.h"
#include "kssl_lcl.h"

#ifndef OPENSSL_NO_KRB5

# ifndef ENOMEM
#  define ENOMEM KRB5KRB_ERR_GENERIC
# endif

/*
 * When OpenSSL is built on Windows, we do not want to require that
 * the Kerberos DLLs be available in order for the OpenSSL DLLs to
 * work.  Therefore, all Kerberos routines are loaded at run time
 * and we do not link to a .LIB file.
 */

# if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
/*
 * The purpose of the following pre-processor statements is to provide
 * compatibility with different releases of MIT Kerberos for Windows.
 * All versions up to 1.2 used macros.  But macros do not allow for
 * a binary compatible interface for DLLs.  Therefore, all macros are
 * being replaced by function calls.  The following code will allow
 * an OpenSSL DLL built on Windows to work whether or not the macro
 * or function form of the routines are utilized.
 */
#  ifdef  krb5_cc_get_principal
#   define NO_DEF_KRB5_CCACHE
#   undef  krb5_cc_get_principal
#  endif
#  define krb5_cc_get_principal    kssl_krb5_cc_get_principal

#  define krb5_free_data_contents  kssl_krb5_free_data_contents
#  define krb5_free_context        kssl_krb5_free_context
#  define krb5_auth_con_free       kssl_krb5_auth_con_free
#  define krb5_free_principal      kssl_krb5_free_principal
#  define krb5_mk_req_extended     kssl_krb5_mk_req_extended
#  define krb5_get_credentials     kssl_krb5_get_credentials
#  define krb5_cc_default          kssl_krb5_cc_default
#  define krb5_sname_to_principal  kssl_krb5_sname_to_principal
#  define krb5_init_context        kssl_krb5_init_context
#  define krb5_free_ticket         kssl_krb5_free_ticket
#  define krb5_rd_req              kssl_krb5_rd_req
#  define krb5_kt_default          kssl_krb5_kt_default
#  define krb5_kt_resolve          kssl_krb5_kt_resolve
/* macros in mit 1.2.2 and earlier; functions in mit 1.2.3 and greater */
#  ifndef krb5_kt_close
#   define krb5_kt_close            kssl_krb5_kt_close
#  endif                        /* krb5_kt_close */
#  ifndef krb5_kt_get_entry
#   define krb5_kt_get_entry        kssl_krb5_kt_get_entry
#  endif                        /* krb5_kt_get_entry */
#  define krb5_auth_con_init       kssl_krb5_auth_con_init

#  define krb5_principal_compare   kssl_krb5_principal_compare
#  define krb5_decrypt_tkt_part    kssl_krb5_decrypt_tkt_part
#  define krb5_timeofday           kssl_krb5_timeofday
#  define krb5_rc_default          kssl_krb5_rc_default

#  ifdef krb5_rc_initialize
#   undef krb5_rc_initialize
#  endif
#  define krb5_rc_initialize   kssl_krb5_rc_initialize

#  ifdef krb5_rc_get_lifespan
#   undef krb5_rc_get_lifespan
#  endif
#  define krb5_rc_get_lifespan kssl_krb5_rc_get_lifespan

#  ifdef krb5_rc_destroy
#   undef krb5_rc_destroy
#  endif
#  define krb5_rc_destroy      kssl_krb5_rc_destroy

#  define valid_cksumtype      kssl_valid_cksumtype
#  define krb5_checksum_size   kssl_krb5_checksum_size
#  define krb5_kt_free_entry   kssl_krb5_kt_free_entry
#  define krb5_auth_con_setrcache  kssl_krb5_auth_con_setrcache
#  define krb5_auth_con_getrcache  kssl_krb5_auth_con_getrcache
#  define krb5_get_server_rcache   kssl_krb5_get_server_rcache

/* Prototypes for built in stubs */
void kssl_krb5_free_data_contents(krb5_context, krb5_data *);
void kssl_krb5_free_principal(krb5_context, krb5_principal);
krb5_error_code kssl_krb5_kt_resolve(krb5_context,
                                     krb5_const char *, krb5_keytab *);
krb5_error_code kssl_krb5_kt_default(krb5_context, krb5_keytab *);
krb5_error_code kssl_krb5_free_ticket(krb5_context, krb5_ticket *);
krb5_error_code kssl_krb5_rd_req(krb5_context, krb5_auth_context *,
                                 krb5_const krb5_data *,
                                 krb5_const_principal, krb5_keytab,
                                 krb5_flags *, krb5_ticket **);

krb5_boolean kssl_krb5_principal_compare(krb5_context, krb5_const_principal,
                                         krb5_const_principal);
krb5_error_code kssl_krb5_mk_req_extended(krb5_context,
                                          krb5_auth_context *,
                                          krb5_const krb5_flags,
                                          krb5_data *,
                                          krb5_creds *, krb5_data *);
krb5_error_code kssl_krb5_init_context(krb5_context *);
void kssl_krb5_free_context(krb5_context);
krb5_error_code kssl_krb5_cc_default(krb5_context, krb5_ccache *);
krb5_error_code kssl_krb5_sname_to_principal(krb5_context,
                                             krb5_const char *,
                                             krb5_const char *,
                                             krb5_int32, krb5_principal *);
krb5_error_code kssl_krb5_get_credentials(krb5_context,
                                          krb5_const krb5_flags,
                                          krb5_ccache,
                                          krb5_creds *, krb5_creds * *);
krb5_error_code kssl_krb5_auth_con_init(krb5_context, krb5_auth_context *);
krb5_error_code kssl_krb5_cc_get_principal(krb5_context context,
                                           krb5_ccache cache,
                                           krb5_principal *principal);
krb5_error_code kssl_krb5_auth_con_free(krb5_context, krb5_auth_context);
size_t kssl_krb5_checksum_size(krb5_context context, krb5_cksumtype ctype);
krb5_boolean kssl_valid_cksumtype(krb5_cksumtype ctype);
krb5_error_code krb5_kt_free_entry(krb5_context, krb5_keytab_entry FAR *);
krb5_error_code kssl_krb5_auth_con_setrcache(krb5_context,
                                             krb5_auth_context, krb5_rcache);
krb5_error_code kssl_krb5_get_server_rcache(krb5_context,
                                            krb5_const krb5_data *,
                                            krb5_rcache *);
krb5_error_code kssl_krb5_auth_con_getrcache(krb5_context,
                                             krb5_auth_context,
                                             krb5_rcache *);

/* Function pointers (almost all Kerberos functions are _stdcall) */
static void (_stdcall *p_krb5_free_data_contents) (krb5_context, krb5_data *)
    = NULL;
static void (_stdcall *p_krb5_free_principal) (krb5_context, krb5_principal)
    = NULL;
static krb5_error_code(_stdcall *p_krb5_kt_resolve)
 (krb5_context, krb5_const char *, krb5_keytab *) = NULL;
static krb5_error_code(_stdcall *p_krb5_kt_default) (krb5_context,
                                                     krb5_keytab *) = NULL;
static krb5_error_code(_stdcall *p_krb5_free_ticket) (krb5_context,
                                                      krb5_ticket *) = NULL;
static krb5_error_code(_stdcall *p_krb5_rd_req) (krb5_context,
                                                 krb5_auth_context *,
                                                 krb5_const krb5_data *,
                                                 krb5_const_principal,
                                                 krb5_keytab, krb5_flags *,
                                                 krb5_ticket **) = NULL;
static krb5_error_code(_stdcall *p_krb5_mk_req_extended)
 (krb5_context, krb5_auth_context *,
  krb5_const krb5_flags, krb5_data *, krb5_creds *, krb5_data *) = NULL;
static krb5_error_code(_stdcall *p_krb5_init_context) (krb5_context *) = NULL;
static void (_stdcall *p_krb5_free_context) (krb5_context) = NULL;
static krb5_error_code(_stdcall *p_krb5_cc_default) (krb5_context,
                                                     krb5_ccache *) = NULL;
static krb5_error_code(_stdcall *p_krb5_sname_to_principal)
 (krb5_context, krb5_const char *, krb5_const char *,
  krb5_int32, krb5_principal *) = NULL;
static krb5_error_code(_stdcall *p_krb5_get_credentials)
 (krb5_context, krb5_const krb5_flags, krb5_ccache,
  krb5_creds *, krb5_creds **) = NULL;
static krb5_error_code(_stdcall *p_krb5_auth_con_init)
 (krb5_context, krb5_auth_context *) = NULL;
static krb5_error_code(_stdcall *p_krb5_cc_get_principal)
 (krb5_context context, krb5_ccache cache, krb5_principal *principal) = NULL;
static krb5_error_code(_stdcall *p_krb5_auth_con_free)
 (krb5_context, krb5_auth_context) = NULL;
static krb5_error_code(_stdcall *p_krb5_decrypt_tkt_part)
 (krb5_context, krb5_const krb5_keyblock *, krb5_ticket *) = NULL;
static krb5_error_code(_stdcall *p_krb5_timeofday)
 (krb5_context context, krb5_int32 *timeret) = NULL;
static krb5_error_code(_stdcall *p_krb5_rc_default)
 (krb5_context context, krb5_rcache *rc) = NULL;
static krb5_error_code(_stdcall *p_krb5_rc_initialize)
 (krb5_context context, krb5_rcache rc, krb5_deltat lifespan) = NULL;
static krb5_error_code(_stdcall *p_krb5_rc_get_lifespan)
 (krb5_context context, krb5_rcache rc, krb5_deltat *lifespan) = NULL;
static krb5_error_code(_stdcall *p_krb5_rc_destroy)
 (krb5_context context, krb5_rcache rc) = NULL;
static krb5_boolean(_stdcall *p_krb5_principal_compare)
 (krb5_context, krb5_const_principal, krb5_const_principal) = NULL;
static size_t (_stdcall *p_krb5_checksum_size) (krb5_context context,
                                                krb5_cksumtype ctype) = NULL;
static krb5_boolean(_stdcall *p_valid_cksumtype) (krb5_cksumtype ctype) =
    NULL;
static krb5_error_code(_stdcall *p_krb5_kt_free_entry)
 (krb5_context, krb5_keytab_entry *) = NULL;
static krb5_error_code(_stdcall *p_krb5_auth_con_setrcache) (krb5_context,
                                                             krb5_auth_context,
                                                             krb5_rcache) =
    NULL;
static krb5_error_code(_stdcall *p_krb5_get_server_rcache) (krb5_context,
                                                            krb5_const
                                                            krb5_data *,
                                                            krb5_rcache *) =
    NULL;
static krb5_error_code(*p_krb5_auth_con_getrcache) (krb5_context,
                                                    krb5_auth_context,
                                                    krb5_rcache *) = NULL;
static krb5_error_code(_stdcall *p_krb5_kt_close) (krb5_context context,
                                                   krb5_keytab keytab) = NULL;
static krb5_error_code(_stdcall *p_krb5_kt_get_entry) (krb5_context context,
                                                       krb5_keytab keytab,
                                                       krb5_const_principal
                                                       principal,
                                                       krb5_kvno vno,
                                                       krb5_enctype enctype,
                                                       krb5_keytab_entry
                                                       *entry) = NULL;
static int krb5_loaded = 0;     /* only attempt to initialize func ptrs once */

/* Function to Load the Kerberos 5 DLL and initialize function pointers */
void load_krb5_dll(void)
{
    HANDLE hKRB5_32;

    krb5_loaded++;
    hKRB5_32 = LoadLibrary(TEXT("KRB5_32"));
    if (!hKRB5_32)
        return;

    (FARPROC) p_krb5_free_data_contents =
        GetProcAddress(hKRB5_32, "krb5_free_data_contents");
    (FARPROC) p_krb5_free_context =
        GetProcAddress(hKRB5_32, "krb5_free_context");
    (FARPROC) p_krb5_auth_con_free =
        GetProcAddress(hKRB5_32, "krb5_auth_con_free");
    (FARPROC) p_krb5_free_principal =
        GetProcAddress(hKRB5_32, "krb5_free_principal");
    (FARPROC) p_krb5_mk_req_extended =
        GetProcAddress(hKRB5_32, "krb5_mk_req_extended");
    (FARPROC) p_krb5_get_credentials =
        GetProcAddress(hKRB5_32, "krb5_get_credentials");
    (FARPROC) p_krb5_cc_get_principal =
        GetProcAddress(hKRB5_32, "krb5_cc_get_principal");
    (FARPROC) p_krb5_cc_default = GetProcAddress(hKRB5_32, "krb5_cc_default");
    (FARPROC) p_krb5_sname_to_principal =
        GetProcAddress(hKRB5_32, "krb5_sname_to_principal");
    (FARPROC) p_krb5_init_context =
        GetProcAddress(hKRB5_32, "krb5_init_context");
    (FARPROC) p_krb5_free_ticket =
        GetProcAddress(hKRB5_32, "krb5_free_ticket");
    (FARPROC) p_krb5_rd_req = GetProcAddress(hKRB5_32, "krb5_rd_req");
    (FARPROC) p_krb5_principal_compare =
        GetProcAddress(hKRB5_32, "krb5_principal_compare");
    (FARPROC) p_krb5_decrypt_tkt_part =
        GetProcAddress(hKRB5_32, "krb5_decrypt_tkt_part");
    (FARPROC) p_krb5_timeofday = GetProcAddress(hKRB5_32, "krb5_timeofday");
    (FARPROC) p_krb5_rc_default = GetProcAddress(hKRB5_32, "krb5_rc_default");
    (FARPROC) p_krb5_rc_initialize =
        GetProcAddress(hKRB5_32, "krb5_rc_initialize");
    (FARPROC) p_krb5_rc_get_lifespan =
        GetProcAddress(hKRB5_32, "krb5_rc_get_lifespan");
    (FARPROC) p_krb5_rc_destroy = GetProcAddress(hKRB5_32, "krb5_rc_destroy");
    (FARPROC) p_krb5_kt_default = GetProcAddress(hKRB5_32, "krb5_kt_default");
    (FARPROC) p_krb5_kt_resolve = GetProcAddress(hKRB5_32, "krb5_kt_resolve");
    (FARPROC) p_krb5_auth_con_init =
        GetProcAddress(hKRB5_32, "krb5_auth_con_init");
    (FARPROC) p_valid_cksumtype = GetProcAddress(hKRB5_32, "valid_cksumtype");
    (FARPROC) p_krb5_checksum_size =
        GetProcAddress(hKRB5_32, "krb5_checksum_size");
    (FARPROC) p_krb5_kt_free_entry =
        GetProcAddress(hKRB5_32, "krb5_kt_free_entry");
    (FARPROC) p_krb5_auth_con_setrcache =
        GetProcAddress(hKRB5_32, "krb5_auth_con_setrcache");
    (FARPROC) p_krb5_get_server_rcache =
        GetProcAddress(hKRB5_32, "krb5_get_server_rcache");
    (FARPROC) p_krb5_auth_con_getrcache =
        GetProcAddress(hKRB5_32, "krb5_auth_con_getrcache");
    (FARPROC) p_krb5_kt_close = GetProcAddress(hKRB5_32, "krb5_kt_close");
    (FARPROC) p_krb5_kt_get_entry =
        GetProcAddress(hKRB5_32, "krb5_kt_get_entry");
}

/* Stubs for each function to be dynamicly loaded */
void kssl_krb5_free_data_contents(krb5_context CO, krb5_data *data)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_free_data_contents)
        p_krb5_free_data_contents(CO, data);
}

krb5_error_code
kssl_krb5_mk_req_extended(krb5_context CO,
                          krb5_auth_context *pACO,
                          krb5_const krb5_flags F,
                          krb5_data *pD1, krb5_creds *pC, krb5_data *pD2)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_mk_req_extended)
        return (p_krb5_mk_req_extended(CO, pACO, F, pD1, pC, pD2));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
kssl_krb5_auth_con_init(krb5_context CO, krb5_auth_context *pACO)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_auth_con_init)
        return (p_krb5_auth_con_init(CO, pACO));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
kssl_krb5_auth_con_free(krb5_context CO, krb5_auth_context ACO)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_auth_con_free)
        return (p_krb5_auth_con_free(CO, ACO));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
kssl_krb5_get_credentials(krb5_context CO,
                          krb5_const krb5_flags F,
                          krb5_ccache CC, krb5_creds *pCR, krb5_creds **ppCR)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_get_credentials)
        return (p_krb5_get_credentials(CO, F, CC, pCR, ppCR));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
kssl_krb5_sname_to_principal(krb5_context CO,
                             krb5_const char *pC1,
                             krb5_const char *pC2,
                             krb5_int32 I, krb5_principal *pPR)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_sname_to_principal)
        return (p_krb5_sname_to_principal(CO, pC1, pC2, I, pPR));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code kssl_krb5_cc_default(krb5_context CO, krb5_ccache *pCC)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_cc_default)
        return (p_krb5_cc_default(CO, pCC));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code kssl_krb5_init_context(krb5_context *pCO)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_init_context)
        return (p_krb5_init_context(pCO));
    else
        return KRB5KRB_ERR_GENERIC;
}

void kssl_krb5_free_context(krb5_context CO)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_free_context)
        p_krb5_free_context(CO);
}

void kssl_krb5_free_principal(krb5_context c, krb5_principal p)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_free_principal)
        p_krb5_free_principal(c, p);
}

krb5_error_code
kssl_krb5_kt_resolve(krb5_context con, krb5_const char *sz, krb5_keytab *kt)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_kt_resolve)
        return (p_krb5_kt_resolve(con, sz, kt));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code kssl_krb5_kt_default(krb5_context con, krb5_keytab *kt)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_kt_default)
        return (p_krb5_kt_default(con, kt));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code kssl_krb5_free_ticket(krb5_context con, krb5_ticket *kt)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_free_ticket)
        return (p_krb5_free_ticket(con, kt));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
kssl_krb5_rd_req(krb5_context con, krb5_auth_context *pacon,
                 krb5_const krb5_data *data,
                 krb5_const_principal princ, krb5_keytab keytab,
                 krb5_flags *flags, krb5_ticket **pptkt)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_rd_req)
        return (p_krb5_rd_req(con, pacon, data, princ, keytab, flags, pptkt));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_boolean
krb5_principal_compare(krb5_context con, krb5_const_principal princ1,
                       krb5_const_principal princ2)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_principal_compare)
        return (p_krb5_principal_compare(con, princ1, princ2));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
krb5_decrypt_tkt_part(krb5_context con, krb5_const krb5_keyblock *keys,
                      krb5_ticket *ticket)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_decrypt_tkt_part)
        return (p_krb5_decrypt_tkt_part(con, keys, ticket));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code krb5_timeofday(krb5_context con, krb5_int32 *timeret)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_timeofday)
        return (p_krb5_timeofday(con, timeret));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code krb5_rc_default(krb5_context con, krb5_rcache *rc)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_rc_default)
        return (p_krb5_rc_default(con, rc));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
krb5_rc_initialize(krb5_context con, krb5_rcache rc, krb5_deltat lifespan)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_rc_initialize)
        return (p_krb5_rc_initialize(con, rc, lifespan));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
krb5_rc_get_lifespan(krb5_context con, krb5_rcache rc, krb5_deltat *lifespanp)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_rc_get_lifespan)
        return (p_krb5_rc_get_lifespan(con, rc, lifespanp));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code krb5_rc_destroy(krb5_context con, krb5_rcache rc)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_rc_destroy)
        return (p_krb5_rc_destroy(con, rc));
    else
        return KRB5KRB_ERR_GENERIC;
}

size_t krb5_checksum_size(krb5_context context, krb5_cksumtype ctype)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_checksum_size)
        return (p_krb5_checksum_size(context, ctype));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_boolean valid_cksumtype(krb5_cksumtype ctype)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_valid_cksumtype)
        return (p_valid_cksumtype(ctype));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code krb5_kt_free_entry(krb5_context con, krb5_keytab_entry *entry)
{
    if (!krb5_loaded)
        load_krb5_dll();

    if (p_krb5_kt_free_entry)
        return (p_krb5_kt_free_entry(con, entry));
    else
        return KRB5KRB_ERR_GENERIC;
}

/* Structure definitions  */
#  ifndef NO_DEF_KRB5_CCACHE
#   ifndef krb5_x
#    define krb5_x(ptr,args) ((ptr)?((*(ptr)) args):(abort(),1))
#    define krb5_xc(ptr,args) ((ptr)?((*(ptr)) args):(abort(),(char*)0))
#   endif

typedef krb5_pointer krb5_cc_cursor; /* cursor for sequential lookup */

typedef struct _krb5_ccache {
    krb5_magic magic;
    struct _krb5_cc_ops FAR *ops;
    krb5_pointer data;
} *krb5_ccache;

typedef struct _krb5_cc_ops {
    krb5_magic magic;
    char *prefix;
    char *(KRB5_CALLCONV *get_name)
     (krb5_context, krb5_ccache);
     krb5_error_code(KRB5_CALLCONV *resolve)
     (krb5_context, krb5_ccache *, const char *);
     krb5_error_code(KRB5_CALLCONV *gen_new)
     (krb5_context, krb5_ccache *);
     krb5_error_code(KRB5_CALLCONV *init)
     (krb5_context, krb5_ccache, krb5_principal);
     krb5_error_code(KRB5_CALLCONV *destroy)
     (krb5_context, krb5_ccache);
     krb5_error_code(KRB5_CALLCONV *close)
     (krb5_context, krb5_ccache);
     krb5_error_code(KRB5_CALLCONV *store)
     (krb5_context, krb5_ccache, krb5_creds *);
     krb5_error_code(KRB5_CALLCONV *retrieve)
     (krb5_context, krb5_ccache, krb5_flags, krb5_creds *, krb5_creds *);
     krb5_error_code(KRB5_CALLCONV *get_princ)
     (krb5_context, krb5_ccache, krb5_principal *);
     krb5_error_code(KRB5_CALLCONV *get_first)
     (krb5_context, krb5_ccache, krb5_cc_cursor *);
     krb5_error_code(KRB5_CALLCONV *get_next)
     (krb5_context, krb5_ccache, krb5_cc_cursor *, krb5_creds *);
     krb5_error_code(KRB5_CALLCONV *end_get)
     (krb5_context, krb5_ccache, krb5_cc_cursor *);
     krb5_error_code(KRB5_CALLCONV *remove_cred)
     (krb5_context, krb5_ccache, krb5_flags, krb5_creds *);
     krb5_error_code(KRB5_CALLCONV *set_flags)
     (krb5_context, krb5_ccache, krb5_flags);
} krb5_cc_ops;
#  endif                        /* NO_DEF_KRB5_CCACHE */

krb5_error_code
    kssl_krb5_cc_get_principal
    (krb5_context context, krb5_ccache cache, krb5_principal *principal) {
    if (p_krb5_cc_get_principal)
        return (p_krb5_cc_get_principal(context, cache, principal));
    else
        return (krb5_x((cache)->ops->get_princ, (context, cache, principal)));
}

krb5_error_code
kssl_krb5_auth_con_setrcache(krb5_context con, krb5_auth_context acon,
                             krb5_rcache rcache)
{
    if (p_krb5_auth_con_setrcache)
        return (p_krb5_auth_con_setrcache(con, acon, rcache));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
kssl_krb5_get_server_rcache(krb5_context con, krb5_const krb5_data *data,
                            krb5_rcache *rcache)
{
    if (p_krb5_get_server_rcache)
        return (p_krb5_get_server_rcache(con, data, rcache));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
kssl_krb5_auth_con_getrcache(krb5_context con, krb5_auth_context acon,
                             krb5_rcache *prcache)
{
    if (p_krb5_auth_con_getrcache)
        return (p_krb5_auth_con_getrcache(con, acon, prcache));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code kssl_krb5_kt_close(krb5_context context, krb5_keytab keytab)
{
    if (p_krb5_kt_close)
        return (p_krb5_kt_close(context, keytab));
    else
        return KRB5KRB_ERR_GENERIC;
}

krb5_error_code
kssl_krb5_kt_get_entry(krb5_context context, krb5_keytab keytab,
                       krb5_const_principal principal, krb5_kvno vno,
                       krb5_enctype enctype, krb5_keytab_entry *entry)
{
    if (p_krb5_kt_get_entry)
        return (p_krb5_kt_get_entry
                (context, keytab, principal, vno, enctype, entry));
    else
        return KRB5KRB_ERR_GENERIC;
}
# endif                         /* OPENSSL_SYS_WINDOWS || OPENSSL_SYS_WIN32 */

/*
 * memory allocation functions for non-temporary storage (e.g. stuff that
 * gets saved into the kssl context)
 */
static void *kssl_calloc(size_t nmemb, size_t size)
{
    void *p;

    p = OPENSSL_malloc(nmemb * size);
    if (p) {
        memset(p, 0, nmemb * size);
    }
    return p;
}

# define kssl_malloc(size) OPENSSL_malloc((size))
# define kssl_realloc(ptr, size) OPENSSL_realloc(ptr, size)
# define kssl_free(ptr) OPENSSL_free((ptr))

char
*kstring(char *string)
{
    static char *null = "[NULL]";

    return ((string == NULL) ? null : string);
}

/*
 * Given KRB5 enctype (basically DES or 3DES), return closest match openssl
 * EVP_ encryption algorithm.  Return NULL for unknown or problematic
 * (krb5_dk_encrypt) enctypes.  Assume ENCTYPE_*_RAW (krb5_raw_encrypt) are
 * OK.
 */
const EVP_CIPHER *kssl_map_enc(krb5_enctype enctype)
{
    switch (enctype) {
    case ENCTYPE_DES_HMAC_SHA1: /* EVP_des_cbc(); */
    case ENCTYPE_DES_CBC_CRC:
    case ENCTYPE_DES_CBC_MD4:
    case ENCTYPE_DES_CBC_MD5:
    case ENCTYPE_DES_CBC_RAW:
        return EVP_des_cbc();
        break;
    case ENCTYPE_DES3_CBC_SHA1: /* EVP_des_ede3_cbc(); */
    case ENCTYPE_DES3_CBC_SHA:
    case ENCTYPE_DES3_CBC_RAW:
        return EVP_des_ede3_cbc();
        break;
    default:
        return NULL;
        break;
    }
}

/*
 * Return true:1 if p "looks like" the start of the real authenticator
 * described in kssl_skip_confound() below.  The ASN.1 pattern is "62 xx 30
 * yy" (APPLICATION-2, SEQUENCE), where xx-yy =~ 2, and xx and yy are
 * possibly multi-byte length fields.
 */
static int kssl_test_confound(unsigned char *p)
{
    int len = 2;
    int xx = 0, yy = 0;

    if (*p++ != 0x62)
        return 0;
    if (*p > 0x82)
        return 0;
    switch (*p) {
    case 0x82:
        p++;
        xx = (*p++ << 8);
        xx += *p++;
        break;
    case 0x81:
        p++;
        xx = *p++;
        break;
    case 0x80:
        return 0;
    default:
        xx = *p++;
        break;
    }
    if (*p++ != 0x30)
        return 0;
    if (*p > 0x82)
        return 0;
    switch (*p) {
    case 0x82:
        p++;
        len += 2;
        yy = (*p++ << 8);
        yy += *p++;
        break;
    case 0x81:
        p++;
        len++;
        yy = *p++;
        break;
    case 0x80:
        return 0;
    default:
        yy = *p++;
        break;
    }

    return (xx - len == yy) ? 1 : 0;
}

/*
 * Allocate, fill, and return cksumlens array of checksum lengths.  This
 * array holds just the unique elements from the krb5_cksumarray[].  array[n]
 * == 0 signals end of data.  The krb5_cksumarray[] was an internal variable
 * that has since been replaced by a more general method for storing the
 * data.  It should not be used.  Instead we use real API calls and make a
 * guess for what the highest assigned CKSUMTYPE_ constant is.  As of 1.2.2
 * it is 0x000c (CKSUMTYPE_HMAC_SHA1_DES3).  So we will use 0x0010.
 */
static size_t *populate_cksumlens(void)
{
    int i, j, n;
    static size_t *cklens = NULL;

# ifdef KRB5_MIT_OLD11
    n = krb5_max_cksum;
# else
    n = 0x0010;
# endif                         /* KRB5_MIT_OLD11 */

# ifdef KRB5CHECKAUTH
    if (!cklens && !(cklens = (size_t *)calloc(sizeof(int), n + 1)))
        return NULL;

    for (i = 0; i < n; i++) {
        if (!valid_cksumtype(i))
            continue;           /* array has holes */
        for (j = 0; j < n; j++) {
            if (cklens[j] == 0) {
                cklens[j] = krb5_checksum_size(NULL, i);
                break;          /* krb5 elem was new: add */
            }
            if (cklens[j] == krb5_checksum_size(NULL, i)) {
                break;          /* ignore duplicate elements */
            }
        }
    }
# endif                         /* KRB5CHECKAUTH */

    return cklens;
}

/*-
 *      Return pointer to start of real authenticator within authenticator, or
 *      return NULL on error.
 *      Decrypted authenticator looks like this:
 *              [0 or 8 byte confounder] [4-24 byte checksum] [real authent'r]
 *      This hackery wouldn't be necessary if MIT KRB5 1.0.6 had the
 *      krb5_auth_con_getcksumtype() function advertised in its krb5.h.
 */
unsigned char *kssl_skip_confound(krb5_enctype etype, unsigned char *a)
{
    int i, conlen;
    size_t cklen;
    static size_t *cksumlens = NULL;
    unsigned char *test_auth;

    conlen = (etype) ? 8 : 0;

    if (!cksumlens && !(cksumlens = populate_cksumlens()))
        return NULL;
    for (i = 0; (cklen = cksumlens[i]) != 0; i++) {
        test_auth = a + conlen + cklen;
        if (kssl_test_confound(test_auth))
            return test_auth;
    }

    return NULL;
}

/*
 * Set kssl_err error info when reason text is a simple string kssl_err =
 * struct { int reason; char text[KSSL_ERR_MAX+1]; }
 */
void kssl_err_set(KSSL_ERR *kssl_err, int reason, char *text)
{
    if (kssl_err == NULL)
        return;

    kssl_err->reason = reason;
    BIO_snprintf(kssl_err->text, KSSL_ERR_MAX, "%s", text);
    return;
}

/*
 * Display contents of krb5_data struct, for debugging
 */
void print_krb5_data(char *label, krb5_data *kdata)
{
    int i;

    fprintf(stderr, "%s[%d] ", label, kdata->length);
    for (i = 0; i < (int)kdata->length; i++) {
        if (0 && isprint((int)kdata->data[i]))
            fprintf(stderr, "%c ", kdata->data[i]);
        else
            fprintf(stderr, "%02x ", (unsigned char)kdata->data[i]);
    }
    fprintf(stderr, "\n");
}

/*
 * Display contents of krb5_authdata struct, for debugging
 */
void print_krb5_authdata(char *label, krb5_authdata **adata)
{
    if (adata == NULL) {
        fprintf(stderr, "%s, authdata==0\n", label);
        return;
    }
    fprintf(stderr, "%s [%p]\n", label, (void *)adata);
# if 0
    {
        int i;
        fprintf(stderr, "%s[at%d:%d] ", label, adata->ad_type, adata->length);
        for (i = 0; i < adata->length; i++) {
            fprintf(stderr, (isprint(adata->contents[i])) ? "%c " : "%02x",
                    adata->contents[i]);
        }
        fprintf(stderr, "\n");
    }
# endif
}

/*
 * Display contents of krb5_keyblock struct, for debugging
 */
void print_krb5_keyblock(char *label, krb5_keyblock *keyblk)
{
    int i;

    if (keyblk == NULL) {
        fprintf(stderr, "%s, keyblk==0\n", label);
        return;
    }
# ifdef KRB5_HEIMDAL
    fprintf(stderr, "%s\n\t[et%d:%d]: ", label, keyblk->keytype,
            keyblk->keyvalue->length);
    for (i = 0; i < (int)keyblk->keyvalue->length; i++) {
        fprintf(stderr, "%02x",
                (unsigned char *)(keyblk->keyvalue->contents)[i]);
    }
    fprintf(stderr, "\n");
# else
    fprintf(stderr, "%s\n\t[et%d:%d]: ", label, keyblk->enctype,
            keyblk->length);
    for (i = 0; i < (int)keyblk->length; i++) {
        fprintf(stderr, "%02x", keyblk->contents[i]);
    }
    fprintf(stderr, "\n");
# endif
}

/*
 * Display contents of krb5_principal_data struct, for debugging
 * (krb5_principal is typedef'd == krb5_principal_data *)
 */
static void print_krb5_princ(char *label, krb5_principal_data *princ)
{
    int i, ui, uj;

    fprintf(stderr, "%s principal Realm: ", label);
    if (princ == NULL)
        return;
    for (ui = 0; ui < (int)princ->realm.length; ui++)
        putchar(princ->realm.data[ui]);
    fprintf(stderr, " (nametype %d) has %d strings:\n", princ->type,
            princ->length);
    for (i = 0; i < (int)princ->length; i++) {
        fprintf(stderr, "\t%d [%d]: ", i, princ->data[i].length);
        for (uj = 0; uj < (int)princ->data[i].length; uj++) {
            putchar(princ->data[i].data[uj]);
        }
        fprintf(stderr, "\n");
    }
    return;
}

/*-     Given krb5 service (typically "kssl") and hostname in kssl_ctx,
 *      Return encrypted Kerberos ticket for service @ hostname.
 *      If authenp is non-NULL, also return encrypted authenticator,
 *      whose data should be freed by caller.
 *      (Originally was: Create Kerberos AP_REQ message for SSL Client.)
 *
 *      19990628        VRS     Started; Returns Kerberos AP_REQ message.
 *      20010409        VRS     Modified for RFC2712; Returns enc tkt.
 *      20010606        VRS     May also return optional authenticator.
 */
krb5_error_code kssl_cget_tkt( /* UPDATE */ KSSL_CTX *kssl_ctx,
                              /*
                               * OUT
                               */ krb5_data **enc_ticketp,
                              /*
                               * UPDATE
                               */ krb5_data *authenp,
                              /*
                               * OUT
                               */ KSSL_ERR *kssl_err)
{
    krb5_error_code krb5rc = KRB5KRB_ERR_GENERIC;
    krb5_context krb5context = NULL;
    krb5_auth_context krb5auth_context = NULL;
    krb5_ccache krb5ccdef = NULL;
    krb5_creds krb5creds, *krb5credsp = NULL;
    krb5_data krb5_app_req;

    kssl_err_set(kssl_err, 0, "");
    memset((char *)&krb5creds, 0, sizeof(krb5creds));

    if (!kssl_ctx) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT, "No kssl_ctx defined.\n");
        goto err;
    } else if (!kssl_ctx->service_host) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "kssl_ctx service_host undefined.\n");
        goto err;
    }

    if ((krb5rc = krb5_init_context(&krb5context)) != 0) {
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "krb5_init_context() fails: %d\n", krb5rc);
        kssl_err->reason = SSL_R_KRB5_C_INIT;
        goto err;
    }

    if ((krb5rc = krb5_sname_to_principal(krb5context,
                                          kssl_ctx->service_host,
                                          (kssl_ctx->service_name) ?
                                          kssl_ctx->service_name : KRB5SVC,
                                          KRB5_NT_SRV_HST,
                                          &krb5creds.server)) != 0) {
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "krb5_sname_to_principal() fails for %s/%s\n",
                     kssl_ctx->service_host,
                     (kssl_ctx->
                      service_name) ? kssl_ctx->service_name : KRB5SVC);
        kssl_err->reason = SSL_R_KRB5_C_INIT;
        goto err;
    }

    if ((krb5rc = krb5_cc_default(krb5context, &krb5ccdef)) != 0) {
        kssl_err_set(kssl_err, SSL_R_KRB5_C_CC_PRINC,
                     "krb5_cc_default fails.\n");
        goto err;
    }

    if ((krb5rc = krb5_cc_get_principal(krb5context, krb5ccdef,
                                        &krb5creds.client)) != 0) {
        kssl_err_set(kssl_err, SSL_R_KRB5_C_CC_PRINC,
                     "krb5_cc_get_principal() fails.\n");
        goto err;
    }

    if ((krb5rc = krb5_get_credentials(krb5context, 0, krb5ccdef,
                                       &krb5creds, &krb5credsp)) != 0) {
        kssl_err_set(kssl_err, SSL_R_KRB5_C_GET_CRED,
                     "krb5_get_credentials() fails.\n");
        goto err;
    }

    *enc_ticketp = &krb5credsp->ticket;
# ifdef KRB5_HEIMDAL
    kssl_ctx->enctype = krb5credsp->session.keytype;
# else
    kssl_ctx->enctype = krb5credsp->keyblock.enctype;
# endif

    krb5rc = KRB5KRB_ERR_GENERIC;
    /*      caller should free data of krb5_app_req  */
    /*
     * 20010406 VRS deleted for real KerberosWrapper 20010605 VRS reinstated
     * to offer Authenticator to KerberosWrapper
     */
    krb5_app_req.length = 0;
    if (authenp) {
        krb5_data krb5in_data;
        const unsigned char *p;
        long arlen;
        KRB5_APREQBODY *ap_req;

        authenp->length = 0;
        krb5in_data.data = NULL;
        krb5in_data.length = 0;
        if ((krb5rc = krb5_mk_req_extended(krb5context,
                                           &krb5auth_context, 0, &krb5in_data,
                                           krb5credsp, &krb5_app_req)) != 0) {
            kssl_err_set(kssl_err, SSL_R_KRB5_C_MK_REQ,
                         "krb5_mk_req_extended() fails.\n");
            goto err;
        }

        arlen = krb5_app_req.length;
        p = (unsigned char *)krb5_app_req.data;
        ap_req = (KRB5_APREQBODY *)d2i_KRB5_APREQ(NULL, &p, arlen);
        if (ap_req) {
            authenp->length = i2d_KRB5_ENCDATA(ap_req->authenticator, NULL);
            if (authenp->length && (authenp->data = malloc(authenp->length))) {
                unsigned char *adp = (unsigned char *)authenp->data;
                authenp->length =
                    i2d_KRB5_ENCDATA(ap_req->authenticator, &adp);
            }
        }

        if (ap_req)
            KRB5_APREQ_free((KRB5_APREQ *) ap_req);
        if (krb5_app_req.length)
            kssl_krb5_free_data_contents(krb5context, &krb5_app_req);
    }
# ifdef KRB5_HEIMDAL
    if (kssl_ctx_setkey(kssl_ctx, &krb5credsp->session)) {
        kssl_err_set(kssl_err, SSL_R_KRB5_C_INIT,
                     "kssl_ctx_setkey() fails.\n");
    }
# else
    if (kssl_ctx_setkey(kssl_ctx, &krb5credsp->keyblock)) {
        kssl_err_set(kssl_err, SSL_R_KRB5_C_INIT,
                     "kssl_ctx_setkey() fails.\n");
    }
# endif
    else
        krb5rc = 0;

 err:
# ifdef KSSL_DEBUG
    kssl_ctx_show(kssl_ctx);
# endif                         /* KSSL_DEBUG */

    if (krb5creds.client)
        krb5_free_principal(krb5context, krb5creds.client);
    if (krb5creds.server)
        krb5_free_principal(krb5context, krb5creds.server);
    if (krb5auth_context)
        krb5_auth_con_free(krb5context, krb5auth_context);
    if (krb5context)
        krb5_free_context(krb5context);
    return (krb5rc);
}

/*-
 *  Given d2i_-decoded asn1ticket, allocate and return a new krb5_ticket.
 *  Return Kerberos error code and kssl_err struct on error.
 *  Allocates krb5_ticket and krb5_principal; caller should free these.
 *
 *      20010410        VRS     Implemented krb5_decode_ticket() as
 *                              old_krb5_decode_ticket(). Missing from MIT1.0.6.
 *      20010615        VRS     Re-cast as openssl/asn1 d2i_*() functions.
 *                              Re-used some of the old krb5_decode_ticket()
 *                              code here.  This tkt should alloc/free just
 *                              like the real thing.
 */
static krb5_error_code kssl_TKT2tkt( /* IN */ krb5_context krb5context,
                                    /*
                                     * IN
                                     */ KRB5_TKTBODY *asn1ticket,
                                    /*
                                     * OUT
                                     */ krb5_ticket **krb5ticket,
                                    /*
                                     * OUT
                                     */ KSSL_ERR *kssl_err)
{
    krb5_error_code krb5rc = KRB5KRB_ERR_GENERIC;
    krb5_ticket *new5ticket = NULL;
    ASN1_GENERALSTRING *gstr_svc, *gstr_host;

    *krb5ticket = NULL;

    if (asn1ticket == NULL || asn1ticket->realm == NULL ||
        asn1ticket->sname == NULL ||
        sk_ASN1_GENERALSTRING_num(asn1ticket->sname->namestring) < 2) {
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "Null field in asn1ticket.\n");
        kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
        return KRB5KRB_ERR_GENERIC;
    }

    if ((new5ticket = (krb5_ticket *)calloc(1, sizeof(krb5_ticket))) == NULL) {
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "Unable to allocate new krb5_ticket.\n");
        kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
        return ENOMEM;          /* or KRB5KRB_ERR_GENERIC; */
    }

    gstr_svc = sk_ASN1_GENERALSTRING_value(asn1ticket->sname->namestring, 0);
    gstr_host = sk_ASN1_GENERALSTRING_value(asn1ticket->sname->namestring, 1);

    if ((krb5rc = kssl_build_principal_2(krb5context,
                                         &new5ticket->server,
                                         asn1ticket->realm->length,
                                         (char *)asn1ticket->realm->data,
                                         gstr_svc->length,
                                         (char *)gstr_svc->data,
                                         gstr_host->length,
                                         (char *)gstr_host->data)) != 0) {
        free(new5ticket);
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "Error building ticket server principal.\n");
        kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
        return krb5rc;          /* or KRB5KRB_ERR_GENERIC; */
    }

    krb5_princ_type(krb5context, new5ticket->server) =
        asn1ticket->sname->nametype->data[0];
    new5ticket->enc_part.enctype = asn1ticket->encdata->etype->data[0];
    new5ticket->enc_part.kvno = asn1ticket->encdata->kvno->data[0];
    new5ticket->enc_part.ciphertext.length =
        asn1ticket->encdata->cipher->length;
    if ((new5ticket->enc_part.ciphertext.data =
         calloc(1, asn1ticket->encdata->cipher->length)) == NULL) {
        free(new5ticket);
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "Error allocating cipher in krb5ticket.\n");
        kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
        return KRB5KRB_ERR_GENERIC;
    } else {
        memcpy(new5ticket->enc_part.ciphertext.data,
               asn1ticket->encdata->cipher->data,
               asn1ticket->encdata->cipher->length);
    }

    *krb5ticket = new5ticket;
    return 0;
}

/*-
 *      Given krb5 service name in KSSL_CTX *kssl_ctx (typically "kssl"),
 *              and krb5 AP_REQ message & message length,
 *      Return Kerberos session key and client principle
 *              to SSL Server in KSSL_CTX *kssl_ctx.
 *
 *      19990702        VRS     Started.
 */
krb5_error_code kssl_sget_tkt( /* UPDATE */ KSSL_CTX *kssl_ctx,
                              /*
                               * IN
                               */ krb5_data *indata,
                              /*
                               * OUT
                               */ krb5_ticket_times *ttimes,
                              /*
                               * OUT
                               */ KSSL_ERR *kssl_err)
{
    krb5_error_code krb5rc = KRB5KRB_ERR_GENERIC;
    static krb5_context krb5context = NULL;
    static krb5_auth_context krb5auth_context = NULL;
    krb5_ticket *krb5ticket = NULL;
    KRB5_TKTBODY *asn1ticket = NULL;
    const unsigned char *p;
    krb5_keytab krb5keytab = NULL;
    krb5_keytab_entry kt_entry;
    krb5_principal krb5server;
    krb5_rcache rcache = NULL;

    kssl_err_set(kssl_err, 0, "");

    if (!kssl_ctx) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT, "No kssl_ctx defined.\n");
        goto err;
    }
# ifdef KSSL_DEBUG
    fprintf(stderr, "in kssl_sget_tkt(%s)\n",
            kstring(kssl_ctx->service_name));
# endif                         /* KSSL_DEBUG */

    if (!krb5context && (krb5rc = krb5_init_context(&krb5context))) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "krb5_init_context() fails.\n");
        goto err;
    }
    if (krb5auth_context &&
        (krb5rc = krb5_auth_con_free(krb5context, krb5auth_context))) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "krb5_auth_con_free() fails.\n");
        goto err;
    } else
        krb5auth_context = NULL;
    if (!krb5auth_context &&
        (krb5rc = krb5_auth_con_init(krb5context, &krb5auth_context))) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "krb5_auth_con_init() fails.\n");
        goto err;
    }

    if ((krb5rc = krb5_auth_con_getrcache(krb5context, krb5auth_context,
                                          &rcache))) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "krb5_auth_con_getrcache() fails.\n");
        goto err;
    }

    if ((krb5rc = krb5_sname_to_principal(krb5context, NULL,
                                          (kssl_ctx->service_name) ?
                                          kssl_ctx->service_name : KRB5SVC,
                                          KRB5_NT_SRV_HST,
                                          &krb5server)) != 0) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "krb5_sname_to_principal() fails.\n");
        goto err;
    }

    if (rcache == NULL) {
        if ((krb5rc = krb5_get_server_rcache(krb5context,
                                             krb5_princ_component(krb5context,
                                                                  krb5server,
                                                                  0),
                                             &rcache))) {
            kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                         "krb5_get_server_rcache() fails.\n");
            goto err;
        }
    }

    if ((krb5rc =
         krb5_auth_con_setrcache(krb5context, krb5auth_context, rcache))) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "krb5_auth_con_setrcache() fails.\n");
        goto err;
    }

    /*
     * kssl_ctx->keytab_file == NULL ==> use Kerberos default
     */
    if (kssl_ctx->keytab_file) {
        krb5rc = krb5_kt_resolve(krb5context, kssl_ctx->keytab_file,
                                 &krb5keytab);
        if (krb5rc) {
            kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                         "krb5_kt_resolve() fails.\n");
            goto err;
        }
    } else {
        krb5rc = krb5_kt_default(krb5context, &krb5keytab);
        if (krb5rc) {
            kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                         "krb5_kt_default() fails.\n");
            goto err;
        }
    }

    /*-     Actual Kerberos5 krb5_recvauth() has initial conversation here
     *      o       check KRB5_SENDAUTH_BADAUTHVERS
     *              unless KRB5_RECVAUTH_SKIP_VERSION
     *      o       check KRB5_SENDAUTH_BADAPPLVERS
     *      o       send "0" msg if all OK
     */

    /*-
     * 20010411 was using AP_REQ instead of true KerberosWrapper
     *
     *  if ((krb5rc = krb5_rd_req(krb5context, &krb5auth_context,
     *                      &krb5in_data, krb5server, krb5keytab,
     *                      &ap_option, &krb5ticket)) != 0)  { Error }
     */

    p = (unsigned char *)indata->data;
    if ((asn1ticket = (KRB5_TKTBODY *)d2i_KRB5_TICKET(NULL, &p,
                                                      (long)indata->length))
        == NULL) {
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "d2i_KRB5_TICKET() ASN.1 decode failure.\n");
        kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
        goto err;
    }

    /*
     * Was: krb5rc = krb5_decode_ticket(krb5in_data,&krb5ticket)) != 0)
     */
    if ((krb5rc = kssl_TKT2tkt(krb5context, asn1ticket, &krb5ticket,
                               kssl_err)) != 0) {
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "Error converting ASN.1 ticket to krb5_ticket.\n");
        kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
        goto err;
    }

    if (!krb5_principal_compare(krb5context, krb5server, krb5ticket->server)) {
        krb5rc = KRB5_PRINC_NOMATCH;
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "server principal != ticket principal\n");
        kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
        goto err;
    }
    if ((krb5rc = krb5_kt_get_entry(krb5context, krb5keytab,
                                    krb5ticket->server,
                                    krb5ticket->enc_part.kvno,
                                    krb5ticket->enc_part.enctype,
                                    &kt_entry)) != 0) {
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "krb5_kt_get_entry() fails with %x.\n", krb5rc);
        kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
        goto err;
    }
    if ((krb5rc = krb5_decrypt_tkt_part(krb5context, &kt_entry.key,
                                        krb5ticket)) != 0) {
        BIO_snprintf(kssl_err->text, KSSL_ERR_MAX,
                     "krb5_decrypt_tkt_part() failed.\n");
        kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
        goto err;
    } else {
        krb5_kt_free_entry(krb5context, &kt_entry);
# ifdef KSSL_DEBUG
        {
            int i;
            krb5_address **paddr = krb5ticket->enc_part2->caddrs;
            fprintf(stderr, "Decrypted ticket fields:\n");
            fprintf(stderr, "\tflags: %X, transit-type: %X",
                    krb5ticket->enc_part2->flags,
                    krb5ticket->enc_part2->transited.tr_type);
            print_krb5_data("\ttransit-data: ",
                            &(krb5ticket->enc_part2->transited.tr_contents));
            fprintf(stderr, "\tcaddrs: %p, authdata: %p\n",
                    krb5ticket->enc_part2->caddrs,
                    krb5ticket->enc_part2->authorization_data);
            if (paddr) {
                fprintf(stderr, "\tcaddrs:\n");
                for (i = 0; paddr[i] != NULL; i++) {
                    krb5_data d;
                    d.length = paddr[i]->length;
                    d.data = paddr[i]->contents;
                    print_krb5_data("\t\tIP: ", &d);
                }
            }
            fprintf(stderr, "\tstart/auth/end times: %d / %d / %d\n",
                    krb5ticket->enc_part2->times.starttime,
                    krb5ticket->enc_part2->times.authtime,
                    krb5ticket->enc_part2->times.endtime);
        }
# endif                         /* KSSL_DEBUG */
    }

    krb5rc = KRB5_NO_TKT_SUPPLIED;
    if (!krb5ticket || !krb5ticket->enc_part2 ||
        !krb5ticket->enc_part2->client ||
        !krb5ticket->enc_part2->client->data ||
        !krb5ticket->enc_part2->session) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_BAD_TICKET,
                     "bad ticket from krb5_rd_req.\n");
    } else if (kssl_ctx_setprinc(kssl_ctx, KSSL_CLIENT,
                                 &krb5ticket->enc_part2->client->realm,
                                 krb5ticket->enc_part2->client->data,
                                 krb5ticket->enc_part2->client->length)) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_BAD_TICKET,
                     "kssl_ctx_setprinc() fails.\n");
    } else if (kssl_ctx_setkey(kssl_ctx, krb5ticket->enc_part2->session)) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_BAD_TICKET,
                     "kssl_ctx_setkey() fails.\n");
    } else if (krb5ticket->enc_part2->flags & TKT_FLG_INVALID) {
        krb5rc = KRB5KRB_AP_ERR_TKT_INVALID;
        kssl_err_set(kssl_err, SSL_R_KRB5_S_BAD_TICKET,
                     "invalid ticket from krb5_rd_req.\n");
    } else
        krb5rc = 0;

    kssl_ctx->enctype = krb5ticket->enc_part.enctype;
    ttimes->authtime = krb5ticket->enc_part2->times.authtime;
    ttimes->starttime = krb5ticket->enc_part2->times.starttime;
    ttimes->endtime = krb5ticket->enc_part2->times.endtime;
    ttimes->renew_till = krb5ticket->enc_part2->times.renew_till;

 err:
# ifdef KSSL_DEBUG
    kssl_ctx_show(kssl_ctx);
# endif                         /* KSSL_DEBUG */

    if (asn1ticket)
        KRB5_TICKET_free((KRB5_TICKET *) asn1ticket);
    if (krb5keytab)
        krb5_kt_close(krb5context, krb5keytab);
    if (krb5ticket)
        krb5_free_ticket(krb5context, krb5ticket);
    if (krb5server)
        krb5_free_principal(krb5context, krb5server);
    return (krb5rc);
}

/*
 * Allocate & return a new kssl_ctx struct.
 */
KSSL_CTX *kssl_ctx_new(void)
{
    return ((KSSL_CTX *)kssl_calloc(1, sizeof(KSSL_CTX)));
}

/*
 * Frees a kssl_ctx struct and any allocated memory it holds.  Returns NULL.
 */
KSSL_CTX *kssl_ctx_free(KSSL_CTX *kssl_ctx)
{
    if (kssl_ctx == NULL)
        return kssl_ctx;

    if (kssl_ctx->key)
        OPENSSL_cleanse(kssl_ctx->key, kssl_ctx->length);
    if (kssl_ctx->key)
        kssl_free(kssl_ctx->key);
    if (kssl_ctx->client_princ)
        kssl_free(kssl_ctx->client_princ);
    if (kssl_ctx->service_host)
        kssl_free(kssl_ctx->service_host);
    if (kssl_ctx->service_name)
        kssl_free(kssl_ctx->service_name);
    if (kssl_ctx->keytab_file)
        kssl_free(kssl_ctx->keytab_file);

    kssl_free(kssl_ctx);
    return (KSSL_CTX *)NULL;
}

/*
 * Given an array of (krb5_data *) entity (and optional realm), set the plain
 * (char *) client_princ or service_host member of the kssl_ctx struct.
 */
krb5_error_code
kssl_ctx_setprinc(KSSL_CTX *kssl_ctx, int which,
                  krb5_data *realm, krb5_data *entity, int nentities)
{
    char **princ;
    int length;
    int i;

    if (kssl_ctx == NULL || entity == NULL)
        return KSSL_CTX_ERR;

    switch (which) {
    case KSSL_CLIENT:
        princ = &kssl_ctx->client_princ;
        break;
    case KSSL_SERVER:
        princ = &kssl_ctx->service_host;
        break;
    default:
        return KSSL_CTX_ERR;
        break;
    }
    if (*princ)
        kssl_free(*princ);

    /* Add up all the entity->lengths */
    length = 0;
    for (i = 0; i < nentities; i++) {
        length += entity[i].length;
    }
    /* Add in space for the '/' character(s) (if any) */
    length += nentities - 1;
    /* Space for the ('@'+realm+NULL | NULL) */
    length += ((realm) ? realm->length + 2 : 1);

    if ((*princ = kssl_calloc(1, length)) == NULL)
        return KSSL_CTX_ERR;
    else {
        for (i = 0; i < nentities; i++) {
            strncat(*princ, entity[i].data, entity[i].length);
            if (i < nentities - 1) {
                strcat(*princ, "/");
            }
        }
        if (realm) {
            strcat(*princ, "@");
            (void)strncat(*princ, realm->data, realm->length);
        }
    }

    return KSSL_CTX_OK;
}

/*-     Set one of the plain (char *) string members of the kssl_ctx struct.
 *      Default values should be:
 *              which == KSSL_SERVICE   =>      "khost" (KRB5SVC)
 *              which == KSSL_KEYTAB    =>      "/etc/krb5.keytab" (KRB5KEYTAB)
 */
krb5_error_code kssl_ctx_setstring(KSSL_CTX *kssl_ctx, int which, char *text)
{
    char **string;

    if (!kssl_ctx)
        return KSSL_CTX_ERR;

    switch (which) {
    case KSSL_SERVICE:
        string = &kssl_ctx->service_name;
        break;
    case KSSL_SERVER:
        string = &kssl_ctx->service_host;
        break;
    case KSSL_CLIENT:
        string = &kssl_ctx->client_princ;
        break;
    case KSSL_KEYTAB:
        string = &kssl_ctx->keytab_file;
        break;
    default:
        return KSSL_CTX_ERR;
        break;
    }
    if (*string)
        kssl_free(*string);

    if (!text) {
        *string = '\0';
        return KSSL_CTX_OK;
    }

    if ((*string = kssl_calloc(1, strlen(text) + 1)) == NULL)
        return KSSL_CTX_ERR;
    else
        strcpy(*string, text);

    return KSSL_CTX_OK;
}

/*
 * Copy the Kerberos session key from a (krb5_keyblock *) to a kssl_ctx
 * struct.  Clear kssl_ctx->key if Kerberos session key is NULL.
 */
krb5_error_code kssl_ctx_setkey(KSSL_CTX *kssl_ctx, krb5_keyblock *session)
{
    int length;
    krb5_enctype enctype;
    krb5_octet FAR *contents = NULL;

    if (!kssl_ctx)
        return KSSL_CTX_ERR;

    if (kssl_ctx->key) {
        OPENSSL_cleanse(kssl_ctx->key, kssl_ctx->length);
        kssl_free(kssl_ctx->key);
    }

    if (session) {

# ifdef KRB5_HEIMDAL
        length = session->keyvalue->length;
        enctype = session->keytype;
        contents = session->keyvalue->contents;
# else
        length = session->length;
        enctype = session->enctype;
        contents = session->contents;
# endif
        kssl_ctx->enctype = enctype;
        kssl_ctx->length = length;
    } else {
        kssl_ctx->enctype = ENCTYPE_UNKNOWN;
        kssl_ctx->length = 0;
        return KSSL_CTX_OK;
    }

    if ((kssl_ctx->key =
         (krb5_octet FAR *)kssl_calloc(1, kssl_ctx->length)) == NULL) {
        kssl_ctx->length = 0;
        return KSSL_CTX_ERR;
    } else
        memcpy(kssl_ctx->key, contents, length);

    return KSSL_CTX_OK;
}

/*
 * Display contents of kssl_ctx struct
 */
void kssl_ctx_show(KSSL_CTX *kssl_ctx)
{
    int i;

    printf("kssl_ctx: ");
    if (kssl_ctx == NULL) {
        printf("NULL\n");
        return;
    } else
        printf("%p\n", (void *)kssl_ctx);

    printf("\tservice:\t%s\n",
           (kssl_ctx->service_name) ? kssl_ctx->service_name : "NULL");
    printf("\tclient:\t%s\n",
           (kssl_ctx->client_princ) ? kssl_ctx->client_princ : "NULL");
    printf("\tserver:\t%s\n",
           (kssl_ctx->service_host) ? kssl_ctx->service_host : "NULL");
    printf("\tkeytab:\t%s\n",
           (kssl_ctx->keytab_file) ? kssl_ctx->keytab_file : "NULL");
    printf("\tkey [%d:%d]:\t", kssl_ctx->enctype, kssl_ctx->length);

    for (i = 0; i < kssl_ctx->length && kssl_ctx->key; i++) {
        printf("%02x", kssl_ctx->key[i]);
    }
    printf("\n");
    return;
}

int kssl_keytab_is_available(KSSL_CTX *kssl_ctx)
{
    krb5_context krb5context = NULL;
    krb5_keytab krb5keytab = NULL;
    krb5_keytab_entry entry;
    krb5_principal princ = NULL;
    krb5_error_code krb5rc = KRB5KRB_ERR_GENERIC;
    int rc = 0;

    if ((krb5rc = krb5_init_context(&krb5context)))
        return (0);

    /*
     * kssl_ctx->keytab_file == NULL ==> use Kerberos default
     */
    if (kssl_ctx->keytab_file) {
        krb5rc = krb5_kt_resolve(krb5context, kssl_ctx->keytab_file,
                                 &krb5keytab);
        if (krb5rc)
            goto exit;
    } else {
        krb5rc = krb5_kt_default(krb5context, &krb5keytab);
        if (krb5rc)
            goto exit;
    }

    /* the host key we are looking for */
    krb5rc = krb5_sname_to_principal(krb5context, NULL,
                                     kssl_ctx->
                                     service_name ? kssl_ctx->service_name :
                                     KRB5SVC, KRB5_NT_SRV_HST, &princ);

    if (krb5rc)
        goto exit;

    krb5rc = krb5_kt_get_entry(krb5context, krb5keytab, princ,
                               /* IGNORE_VNO */
                               0,
                               /* IGNORE_ENCTYPE */
                               0, &entry);
    if (krb5rc == KRB5_KT_NOTFOUND) {
        rc = 1;
        goto exit;
    } else if (krb5rc)
        goto exit;

    krb5_kt_free_entry(krb5context, &entry);
    rc = 1;

 exit:
    if (krb5keytab)
        krb5_kt_close(krb5context, krb5keytab);
    if (princ)
        krb5_free_principal(krb5context, princ);
    if (krb5context)
        krb5_free_context(krb5context);
    return (rc);
}

int kssl_tgt_is_available(KSSL_CTX *kssl_ctx)
{
    krb5_error_code krb5rc = KRB5KRB_ERR_GENERIC;
    krb5_context krb5context = NULL;
    krb5_ccache krb5ccdef = NULL;
    krb5_creds krb5creds, *krb5credsp = NULL;
    int rc = 0;

    memset((char *)&krb5creds, 0, sizeof(krb5creds));

    if (!kssl_ctx)
        return (0);

    if (!kssl_ctx->service_host)
        return (0);

    if ((krb5rc = krb5_init_context(&krb5context)) != 0)
        goto err;

    if ((krb5rc = krb5_sname_to_principal(krb5context,
                                          kssl_ctx->service_host,
                                          (kssl_ctx->service_name) ?
                                          kssl_ctx->service_name : KRB5SVC,
                                          KRB5_NT_SRV_HST,
                                          &krb5creds.server)) != 0)
        goto err;

    if ((krb5rc = krb5_cc_default(krb5context, &krb5ccdef)) != 0)
        goto err;

    if ((krb5rc = krb5_cc_get_principal(krb5context, krb5ccdef,
                                        &krb5creds.client)) != 0)
        goto err;

    if ((krb5rc = krb5_get_credentials(krb5context, 0, krb5ccdef,
                                       &krb5creds, &krb5credsp)) != 0)
        goto err;

    rc = 1;

 err:
# ifdef KSSL_DEBUG
    kssl_ctx_show(kssl_ctx);
# endif                         /* KSSL_DEBUG */

    if (krb5creds.client)
        krb5_free_principal(krb5context, krb5creds.client);
    if (krb5creds.server)
        krb5_free_principal(krb5context, krb5creds.server);
    if (krb5context)
        krb5_free_context(krb5context);
    return (rc);
}

# if !defined(OPENSSL_SYS_WINDOWS) && !defined(OPENSSL_SYS_WIN32)
void kssl_krb5_free_data_contents(krb5_context context, krb5_data *data)
{
#  ifdef KRB5_HEIMDAL
    data->length = 0;
    if (data->data)
        free(data->data);
#  elif defined(KRB5_MIT_OLD11)
    if (data->data) {
        krb5_xfree(data->data);
        data->data = 0;
    }
#  else
    krb5_free_data_contents(NULL, data);
#  endif
}
# endif
/* !OPENSSL_SYS_WINDOWS && !OPENSSL_SYS_WIN32 */

/*
 * Given pointers to KerberosTime and struct tm structs, convert the
 * KerberosTime string to struct tm.  Note that KerberosTime is a
 * ASN1_GENERALIZEDTIME value, constrained to GMT with no fractional seconds
 * as defined in RFC 1510.  Return pointer to the (partially) filled in
 * struct tm on success, return NULL on failure.
 */
static struct tm *k_gmtime(ASN1_GENERALIZEDTIME *gtime, struct tm *k_tm)
{
    char c, *p;

    if (!k_tm)
        return NULL;
    if (gtime == NULL || gtime->length < 14)
        return NULL;
    if (gtime->data == NULL)
        return NULL;

    p = (char *)&gtime->data[14];

    c = *p;
    *p = '\0';
    p -= 2;
    k_tm->tm_sec = atoi(p);
    *(p + 2) = c;
    c = *p;
    *p = '\0';
    p -= 2;
    k_tm->tm_min = atoi(p);
    *(p + 2) = c;
    c = *p;
    *p = '\0';
    p -= 2;
    k_tm->tm_hour = atoi(p);
    *(p + 2) = c;
    c = *p;
    *p = '\0';
    p -= 2;
    k_tm->tm_mday = atoi(p);
    *(p + 2) = c;
    c = *p;
    *p = '\0';
    p -= 2;
    k_tm->tm_mon = atoi(p) - 1;
    *(p + 2) = c;
    c = *p;
    *p = '\0';
    p -= 4;
    k_tm->tm_year = atoi(p) - 1900;
    *(p + 4) = c;

    return k_tm;
}

/*
 * Helper function for kssl_validate_times().  We need context->clockskew,
 * but krb5_context is an opaque struct.  So we try to sneek the clockskew
 * out through the replay cache.  If that fails just return a likely default
 * (300 seconds).
 */
static krb5_deltat get_rc_clockskew(krb5_context context)
{
    krb5_rcache rc;
    krb5_deltat clockskew;

    if (krb5_rc_default(context, &rc))
        return KSSL_CLOCKSKEW;
    if (krb5_rc_initialize(context, rc, 0))
        return KSSL_CLOCKSKEW;
    if (krb5_rc_get_lifespan(context, rc, &clockskew)) {
        clockskew = KSSL_CLOCKSKEW;
    }
    (void)krb5_rc_destroy(context, rc);
    return clockskew;
}

/*
 * kssl_validate_times() combines (and more importantly exposes) the MIT KRB5
 * internal function krb5_validate_times() and the in_clock_skew() macro.
 * The authenticator client time is checked to be within clockskew secs of
 * the current time and the current time is checked to be within the ticket
 * start and expire times.  Either check may be omitted by supplying a NULL
 * value.  Returns 0 for valid times, SSL_R_KRB5* error codes otherwise.  See
 * Also: (Kerberos source)/krb5/lib/krb5/krb/valid_times.c 20010420 VRS
 */
krb5_error_code kssl_validate_times(krb5_timestamp atime,
                                    krb5_ticket_times *ttimes)
{
    krb5_deltat skew;
    krb5_timestamp start, now;
    krb5_error_code rc;
    krb5_context context;

    if ((rc = krb5_init_context(&context)))
        return SSL_R_KRB5_S_BAD_TICKET;
    skew = get_rc_clockskew(context);
    if ((rc = krb5_timeofday(context, &now)))
        return SSL_R_KRB5_S_BAD_TICKET;
    krb5_free_context(context);

    if (atime && labs(atime - now) >= skew)
        return SSL_R_KRB5_S_TKT_SKEW;

    if (!ttimes)
        return 0;

    start = (ttimes->starttime != 0) ? ttimes->starttime : ttimes->authtime;
    if (start - now > skew)
        return SSL_R_KRB5_S_TKT_NYV;
    if ((now - ttimes->endtime) > skew)
        return SSL_R_KRB5_S_TKT_EXPIRED;

# ifdef KSSL_DEBUG
    fprintf(stderr, "kssl_validate_times: %d |<-  | %d - %d | < %d  ->| %d\n",
            start, atime, now, skew, ttimes->endtime);
# endif                         /* KSSL_DEBUG */

    return 0;
}

/*
 * Decode and decrypt given DER-encoded authenticator, then pass
 * authenticator ctime back in *atimep (or 0 if time unavailable).  Returns
 * krb5_error_code and kssl_err on error.  A NULL authenticator
 * (authentp->length == 0) is not considered an error.  Note that
 * kssl_check_authent() makes use of the KRB5 session key; you must call
 * kssl_sget_tkt() to get the key before calling this routine.
 */
krb5_error_code kssl_check_authent(
                                      /*
                                       * IN
                                       */ KSSL_CTX *kssl_ctx,
                                      /*
                                       * IN
                                       */ krb5_data *authentp,
                                      /*
                                       * OUT
                                       */ krb5_timestamp *atimep,
                                      /*
                                       * OUT
                                       */ KSSL_ERR *kssl_err)
{
    krb5_error_code krb5rc = 0;
    KRB5_ENCDATA *dec_authent = NULL;
    KRB5_AUTHENTBODY *auth = NULL;
    krb5_enctype enctype;
    EVP_CIPHER_CTX ciph_ctx;
    const EVP_CIPHER *enc = NULL;
    unsigned char iv[EVP_MAX_IV_LENGTH];
    const unsigned char *p;
    unsigned char *unenc_authent;
    int outl, unencbufsize;
    struct tm tm_time, *tm_l, *tm_g;
    time_t now, tl, tg, tr, tz_offset;
    struct tm gmt_result = {0};
    struct tm lt_result = {0};

    EVP_CIPHER_CTX_init(&ciph_ctx);
    *atimep = 0;
    kssl_err_set(kssl_err, 0, "");

# ifndef KRB5CHECKAUTH
    authentp = NULL;
# else
#  if     KRB5CHECKAUTH == 0
    authentp = NULL;
#  endif
# endif                         /* KRB5CHECKAUTH */

    if (authentp == NULL || authentp->length == 0)
        return 0;

# ifdef KSSL_DEBUG
    {
        unsigned int ui;
        fprintf(stderr, "kssl_check_authent: authenticator[%d]:\n",
                authentp->length);
        p = authentp->data;
        for (ui = 0; ui < authentp->length; ui++)
            fprintf(stderr, "%02x ", p[ui]);
        fprintf(stderr, "\n");
    }
# endif                         /* KSSL_DEBUG */

    unencbufsize = 2 * authentp->length;
    if ((unenc_authent = calloc(1, unencbufsize)) == NULL) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "Unable to allocate authenticator buffer.\n");
        krb5rc = KRB5KRB_ERR_GENERIC;
        goto err;
    }

    p = (unsigned char *)authentp->data;
    if ((dec_authent = d2i_KRB5_ENCDATA(NULL, &p,
                                        (long)authentp->length)) == NULL) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "Error decoding authenticator.\n");
        krb5rc = KRB5KRB_AP_ERR_BAD_INTEGRITY;
        goto err;
    }

    enctype = dec_authent->etype->data[0]; /* should = kssl_ctx->enctype */
# if !defined(KRB5_MIT_OLD11)
    switch (enctype) {
    case ENCTYPE_DES3_CBC_SHA1: /* EVP_des_ede3_cbc(); */
    case ENCTYPE_DES3_CBC_SHA:
    case ENCTYPE_DES3_CBC_RAW:
        krb5rc = 0;             /* Skip, can't handle derived keys */
        goto err;
    }
# endif
    enc = kssl_map_enc(enctype);
    memset(iv, 0, sizeof(iv));   /* per RFC 1510 */

    if (enc == NULL) {
        /*
         * Disable kssl_check_authent for ENCTYPE_DES3_CBC_SHA1.  This
         * enctype indicates the authenticator was encrypted using key-usage
         * derived keys which openssl cannot decrypt.
         */
        goto err;
    }

    if (!EVP_CipherInit(&ciph_ctx, enc, kssl_ctx->key, iv, 0)) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "EVP_CipherInit error decrypting authenticator.\n");
        krb5rc = KRB5KRB_AP_ERR_BAD_INTEGRITY;
        goto err;
    }
    outl = dec_authent->cipher->length;
    if (!EVP_Cipher
        (&ciph_ctx, unenc_authent, dec_authent->cipher->data, outl)) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "EVP_Cipher error decrypting authenticator.\n");
        krb5rc = KRB5KRB_AP_ERR_BAD_INTEGRITY;
        goto err;
    }
    EVP_CIPHER_CTX_cleanup(&ciph_ctx);

# ifdef KSSL_DEBUG
    {
        int padl;
        fprintf(stderr, "kssl_check_authent: decrypted authenticator[%d] =\n",
                outl);
        for (padl = 0; padl < outl; padl++)
            fprintf(stderr, "%02x ", unenc_authent[padl]);
        fprintf(stderr, "\n");
    }
# endif                         /* KSSL_DEBUG */

    if ((p = kssl_skip_confound(enctype, unenc_authent)) == NULL) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "confounded by authenticator.\n");
        krb5rc = KRB5KRB_AP_ERR_BAD_INTEGRITY;
        goto err;
    }
    outl -= p - unenc_authent;

    if ((auth = (KRB5_AUTHENTBODY *)d2i_KRB5_AUTHENT(NULL, &p,
                                                     (long)outl)) == NULL) {
        kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
                     "Error decoding authenticator body.\n");
        krb5rc = KRB5KRB_AP_ERR_BAD_INTEGRITY;
        goto err;
    }

    memset(&tm_time, 0, sizeof(struct tm));
    if (k_gmtime(auth->ctime, &tm_time) &&
        ((tr = mktime(&tm_time)) != (time_t)(-1))) {
        now = time(&now);
        tm_g = OPENSSL_gmtime(&now, &gmt_result);

# if defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32) && \
            !defined(OPENSSL_SYS_OS2) && !defined(OPENSSL_SYS_SUNOS) && \
            (!defined(OPENSSL_SYS_VMS) || defined(localtime_r))
        tm_l = localtime_r(&now, &lt_result);
# else
        tm_l = localtime(&now);
# endif

        tl = mktime(tm_l);
        tg = mktime(tm_g);
        tz_offset = tg - tl;

        *atimep = (krb5_timestamp)(tr - tz_offset);
    }
# ifdef KSSL_DEBUG
    fprintf(stderr, "kssl_check_authent: returns %d for client time ",
            *atimep);
    if (auth && auth->ctime && auth->ctime->length && auth->ctime->data)
        fprintf(stderr, "%.*s\n", auth->ctime->length, auth->ctime->data);
    else
        fprintf(stderr, "NULL\n");
# endif                         /* KSSL_DEBUG */

 err:
    if (auth)
        KRB5_AUTHENT_free((KRB5_AUTHENT *) auth);
    if (dec_authent)
        KRB5_ENCDATA_free(dec_authent);
    if (unenc_authent)
        free(unenc_authent);
    EVP_CIPHER_CTX_cleanup(&ciph_ctx);
    return krb5rc;
}

/*
 * Replaces krb5_build_principal_ext(), with varargs length == 2 (svc, host),
 * because I don't know how to stub varargs.  Returns krb5_error_code ==
 * ENOMEM on alloc error, otherwise passes back newly constructed principal,
 * which should be freed by caller.
 */
krb5_error_code kssl_build_principal_2(
                                          /*
                                           * UPDATE
                                           */ krb5_context context,
                                          /*
                                           * OUT
                                           */ krb5_principal *princ,
                                          /*
                                           * IN
                                           */ int rlen, const char *realm,
                                          /*
                                           * IN
                                           */ int slen, const char *svc,
                                          /*
                                           * IN
                                           */ int hlen, const char *host)
{
    krb5_data *p_data = NULL;
    krb5_principal new_p = NULL;
    char *new_r = NULL;

    if ((p_data = (krb5_data *)calloc(2, sizeof(krb5_data))) == NULL ||
        (new_p = (krb5_principal)calloc(1, sizeof(krb5_principal_data)))
        == NULL)
        goto err;
    new_p->length = 2;
    new_p->data = p_data;

    if ((new_r = calloc(1, rlen + 1)) == NULL)
        goto err;
    memcpy(new_r, realm, rlen);
    krb5_princ_set_realm_length(context, new_p, rlen);
    krb5_princ_set_realm_data(context, new_p, new_r);

    if ((new_p->data[0].data = calloc(1, slen + 1)) == NULL)
        goto err;
    memcpy(new_p->data[0].data, svc, slen);
    new_p->data[0].length = slen;

    if ((new_p->data[1].data = calloc(1, hlen + 1)) == NULL)
        goto err;
    memcpy(new_p->data[1].data, host, hlen);
    new_p->data[1].length = hlen;

    krb5_princ_type(context, new_p) = KRB5_NT_UNKNOWN;
    *princ = new_p;
    return 0;

 err:
    if (new_p && new_p[0].data)
        free(new_p[0].data);
    if (new_p && new_p[1].data)
        free(new_p[1].data);
    if (new_p)
        free(new_p);
    if (new_r)
        free(new_r);
    return ENOMEM;
}

void SSL_set0_kssl_ctx(SSL *s, KSSL_CTX *kctx)
{
    s->kssl_ctx = kctx;
}

KSSL_CTX *SSL_get0_kssl_ctx(SSL *s)
{
    return s->kssl_ctx;
}

char *kssl_ctx_get0_client_princ(KSSL_CTX *kctx)
{
    if (kctx)
        return kctx->client_princ;
    return NULL;
}

#else                           /* !OPENSSL_NO_KRB5 */

# if defined(PEDANTIC) || defined(OPENSSL_SYS_VMS)
static void *dummy = &dummy;
# endif

#endif                          /* !OPENSSL_NO_KRB5 */