Adding upstream version 1:9.11.5.P4+dfsg.upstream/1%9.11.5.P4+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1825 insertions, 0 deletions

diff --git a/lib/dns/spnego.c b/lib/dns/spnego.c
new file mode 100644
index 0000000..ad77f24
--- /dev/null
+++ b/lib/dns/spnego.c
@@ -0,0 +1,1825 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file
+ * \brief
+ * Portable SPNEGO implementation.
+ *
+ * This is part of a portable implementation of the SPNEGO protocol
+ * (RFCs 2478 and 4178).  This implementation uses the RFC 4178 ASN.1
+ * module but is not a full implementation of the RFC 4178 protocol;
+ * at the moment, we only support GSS-TSIG with Kerberos
+ * authentication, so we only need enough of the SPNEGO protocol to
+ * support that.
+ *
+ * The files that make up this portable SPNEGO implementation are:
+ * \li	spnego.c	(this file)
+ * \li	spnego.h	(API SPNEGO exports to the rest of lib/dns)
+ * \li	spnego.asn1	(SPNEGO ASN.1 module)
+ * \li	spnego_asn1.c	(routines generated from spngo.asn1)
+ * \li	spnego_asn1.pl	(perl script to generate spnego_asn1.c)
+ *
+ * Everything but the functions exported in spnego.h is static, to
+ * avoid possible conflicts with other libraries (particularly Heimdal,
+ * since much of this code comes from Heimdal by way of mod_auth_kerb).
+ *
+ * spnego_asn1.c is shipped as part of lib/dns because generating it
+ * requires both Perl and the Heimdal ASN.1 compiler.  See
+ * spnego_asn1.pl for further details.  We've tried to eliminate all
+ * compiler warnings from the generated code, but you may see a few
+ * when using a compiler version we haven't tested yet.
+ */
+
+/*
+ * Portions of this code were derived from mod_auth_kerb and Heimdal.
+ * These packages are available from:
+ *
+ *   http://modauthkerb.sourceforge.net/
+ *   http://www.pdc.kth.se/heimdal/
+ *
+ * and were released under the following licenses:
+ *
+ * ----------------------------------------------------------------
+ *
+ * Copyright (c) 2004 Masarykova universita
+ * (Masaryk University, Brno, Czech Republic)
+ * 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. Neither the name of the University nor the names of its contributors may
+ *    be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS 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 COPYRIGHT OWNER OR 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.
+ *
+ * ----------------------------------------------------------------
+ *
+ * Copyright (c) 1997 - 2003 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * 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. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS 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 INSTITUTE OR 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.
+ */
+
+/*
+ * XXXSRA We should omit this file entirely in Makefile.in via autoconf,
+ * but this will keep it from generating errors until that's written.
+ */
+
+#ifdef GSSAPI
+
+/*
+ * XXXSRA Some of the following files are almost certainly unnecessary,
+ * but using this list (borrowed from gssapictx.c) gets rid of some
+ * whacky compilation errors when building with MSVC and should be
+ * harmless in any case.
+ */
+
+#include <config.h>
+
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#include <isc/buffer.h>
+#include <isc/dir.h>
+#include <isc/entropy.h>
+#include <isc/lex.h>
+#include <isc/mem.h>
+#include <isc/once.h>
+#include <isc/random.h>
+#include <isc/safe.h>
+#include <isc/string.h>
+#include <isc/time.h>
+#include <isc/util.h>
+
+#include <dns/fixedname.h>
+#include <dns/name.h>
+#include <dns/rdata.h>
+#include <dns/rdataclass.h>
+#include <dns/result.h>
+#include <dns/types.h>
+#include <dns/keyvalues.h>
+#include <dns/log.h>
+
+#include <dst/gssapi.h>
+#include <dst/result.h>
+
+#include "dst_internal.h"
+
+/*
+ * The API we export
+ */
+#include "spnego.h"
+
+/* asn1_err.h */
+/* Generated from ../../../lib/asn1/asn1_err.et */
+
+#ifndef ERROR_TABLE_BASE_asn1
+/* these may be brought in already via gssapi_krb5.h */
+typedef enum asn1_error_number {
+	ASN1_BAD_TIMEFORMAT = 1859794432,
+	ASN1_MISSING_FIELD = 1859794433,
+	ASN1_MISPLACED_FIELD = 1859794434,
+	ASN1_TYPE_MISMATCH = 1859794435,
+	ASN1_OVERFLOW = 1859794436,
+	ASN1_OVERRUN = 1859794437,
+	ASN1_BAD_ID = 1859794438,
+	ASN1_BAD_LENGTH = 1859794439,
+	ASN1_BAD_FORMAT = 1859794440,
+	ASN1_PARSE_ERROR = 1859794441
+} asn1_error_number;
+
+#define ERROR_TABLE_BASE_asn1 1859794432
+#endif
+
+#define __asn1_common_definitions__
+
+typedef struct octet_string {
+	size_t length;
+	void *data;
+} octet_string;
+
+typedef char *general_string;
+
+typedef char *utf8_string;
+
+typedef struct oid {
+	size_t length;
+	unsigned *components;
+} oid;
+
+/* der.h */
+
+typedef enum {
+	ASN1_C_UNIV = 0, ASN1_C_APPL = 1,
+	ASN1_C_CONTEXT = 2, ASN1_C_PRIVATE = 3
+} Der_class;
+
+typedef enum {
+	PRIM = 0, CONS = 1
+} Der_type;
+
+/* Universal tags */
+
+enum {
+	UT_Boolean = 1,
+	UT_Integer = 2,
+	UT_BitString = 3,
+	UT_OctetString = 4,
+	UT_Null = 5,
+	UT_OID = 6,
+	UT_Enumerated = 10,
+	UT_Sequence = 16,
+	UT_Set = 17,
+	UT_PrintableString = 19,
+	UT_IA5String = 22,
+	UT_UTCTime = 23,
+	UT_GeneralizedTime = 24,
+	UT_VisibleString = 26,
+	UT_GeneralString = 27
+};
+
+#define ASN1_INDEFINITE 0xdce0deed
+
+static int
+der_get_length(const unsigned char *p, size_t len,
+	       size_t * val, size_t * size);
+
+static int
+der_get_octet_string(const unsigned char *p, size_t len,
+		     octet_string * data, size_t * size);
+static int
+der_get_oid(const unsigned char *p, size_t len,
+	    oid * data, size_t * size);
+static int
+der_get_tag(const unsigned char *p, size_t len,
+	    Der_class * xclass, Der_type * type,
+	    int *tag, size_t * size);
+
+static int
+der_match_tag(const unsigned char *p, size_t len,
+	      Der_class xclass, Der_type type,
+	      int tag, size_t * size);
+static int
+der_match_tag_and_length(const unsigned char *p, size_t len,
+			 Der_class xclass, Der_type type, int tag,
+			 size_t * length_ret, size_t * size);
+
+static int
+decode_oid(const unsigned char *p, size_t len,
+	   oid * k, size_t * size);
+
+static int
+decode_enumerated(const unsigned char *p, size_t len, void *num, size_t *size);
+
+static int
+decode_octet_string(const unsigned char *, size_t, octet_string *, size_t *);
+
+static int
+der_put_int(unsigned char *p, size_t len, int val, size_t *);
+
+static int
+der_put_length(unsigned char *p, size_t len, size_t val, size_t *);
+
+static int
+der_put_octet_string(unsigned char *p, size_t len,
+		     const octet_string * data, size_t *);
+static int
+der_put_oid(unsigned char *p, size_t len,
+	    const oid * data, size_t * size);
+static int
+der_put_tag(unsigned char *p, size_t len, Der_class xclass, Der_type type,
+	    int tag, size_t *);
+static int
+der_put_length_and_tag(unsigned char *, size_t, size_t,
+		       Der_class, Der_type, int, size_t *);
+
+static int
+encode_enumerated(unsigned char *p, size_t len, const void *data, size_t *);
+
+static int
+encode_octet_string(unsigned char *p, size_t len,
+		    const octet_string * k, size_t *);
+static int
+encode_oid(unsigned char *p, size_t len,
+	   const oid * k, size_t *);
+
+static void
+free_octet_string(octet_string * k);
+
+static void
+free_oid  (oid * k);
+
+static size_t
+length_len(size_t len);
+
+static int
+fix_dce(size_t reallen, size_t * len);
+
+/*
+ * Include stuff generated by the ASN.1 compiler.
+ */
+
+#include "spnego_asn1.c"
+
+/*
+ * Force the oid arrays to be uint64_t aligned to silence warnings
+ * about the arrays not being properly aligned for (void *).
+ */
+typedef union { unsigned char b[8]; uint64_t _align; } aligned8;
+typedef union { unsigned char b[16]; uint64_t _align[2]; } aligned16;
+
+static aligned16 gss_krb5_mech_oid_bytes = {
+	{ 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x12, 0x01, 0x02, 0x02 }
+};
+
+static gss_OID_desc gss_krb5_mech_oid_desc = {
+	9, gss_krb5_mech_oid_bytes.b
+};
+
+static gss_OID GSS_KRB5_MECH = &gss_krb5_mech_oid_desc;
+
+static aligned16 gss_mskrb5_mech_oid_bytes = {
+	{ 0x2a, 0x86, 0x48, 0x82, 0xf7, 0x12, 0x01, 0x02, 0x02 }
+};
+
+static gss_OID_desc gss_mskrb5_mech_oid_desc = {
+	9, gss_mskrb5_mech_oid_bytes.b
+};
+
+static gss_OID GSS_MSKRB5_MECH = &gss_mskrb5_mech_oid_desc;
+
+static aligned8 gss_spnego_mech_oid_bytes = {
+	{ 0x2b, 0x06, 0x01, 0x05, 0x05, 0x02 }
+};
+
+static gss_OID_desc gss_spnego_mech_oid_desc = {
+	6, gss_spnego_mech_oid_bytes.b
+};
+
+static gss_OID GSS_SPNEGO_MECH = &gss_spnego_mech_oid_desc;
+
+/* spnegokrb5_locl.h */
+
+static OM_uint32
+gssapi_spnego_encapsulate(OM_uint32 *,
+			  unsigned char *,
+			  size_t,
+			  gss_buffer_t,
+			  const gss_OID);
+
+static OM_uint32
+gssapi_spnego_decapsulate(OM_uint32 *,
+			  gss_buffer_t,
+			  unsigned char **,
+			  size_t *,
+			  const gss_OID);
+
+/* mod_auth_kerb.c */
+
+static int
+cmp_gss_type(gss_buffer_t token, gss_OID gssoid)
+{
+	unsigned char *p;
+	size_t len;
+
+	if (token->length == 0U)
+		return (GSS_S_DEFECTIVE_TOKEN);
+
+	p = token->value;
+	if (*p++ != 0x60)
+		return (GSS_S_DEFECTIVE_TOKEN);
+	len = *p++;
+	if (len & 0x80) {
+		if ((len & 0x7f) > 4U)
+			return (GSS_S_DEFECTIVE_TOKEN);
+		p += len & 0x7f;
+	}
+	if (*p++ != 0x06)
+		return (GSS_S_DEFECTIVE_TOKEN);
+
+	if (((OM_uint32) *p++) != gssoid->length)
+		return (GSS_S_DEFECTIVE_TOKEN);
+
+	return (isc_safe_memcompare(p, gssoid->elements, gssoid->length));
+}
+
+/* accept_sec_context.c */
+/*
+ * SPNEGO wrapper for Kerberos5 GSS-API kouril@ics.muni.cz, 2003 (mostly
+ * based on Heimdal code)
+ */
+
+static OM_uint32
+code_NegTokenArg(OM_uint32 * minor_status,
+		 const NegTokenResp * resp,
+		 unsigned char **outbuf,
+		 size_t * outbuf_size)
+{
+	OM_uint32 ret;
+	u_char *buf;
+	size_t buf_size, buf_len = 0;
+
+	buf_size = 1024;
+	buf = malloc(buf_size);
+	if (buf == NULL) {
+		*minor_status = ENOMEM;
+		return (GSS_S_FAILURE);
+	}
+	do {
+		ret = encode_NegTokenResp(buf + buf_size - 1,
+					  buf_size,
+					  resp, &buf_len);
+		if (ret == 0) {
+			size_t tmp;
+
+			ret = der_put_length_and_tag(buf + buf_size - buf_len - 1,
+						     buf_size - buf_len,
+						     buf_len,
+						     ASN1_C_CONTEXT,
+						     CONS,
+						     1,
+						     &tmp);
+			if (ret == 0)
+				buf_len += tmp;
+		}
+		if (ret) {
+			if (ret == ASN1_OVERFLOW) {
+				u_char *tmp;
+
+				buf_size *= 2;
+				tmp = realloc(buf, buf_size);
+				if (tmp == NULL) {
+					*minor_status = ENOMEM;
+					free(buf);
+					return (GSS_S_FAILURE);
+				}
+				buf = tmp;
+			} else {
+				*minor_status = ret;
+				free(buf);
+				return (GSS_S_FAILURE);
+			}
+		}
+	} while (ret == ASN1_OVERFLOW);
+
+	*outbuf = malloc(buf_len);
+	if (*outbuf == NULL) {
+		*minor_status = ENOMEM;
+		free(buf);
+		return (GSS_S_FAILURE);
+	}
+	memmove(*outbuf, buf + buf_size - buf_len, buf_len);
+	*outbuf_size = buf_len;
+
+	free(buf);
+
+	return (GSS_S_COMPLETE);
+}
+
+static OM_uint32
+send_reject(OM_uint32 * minor_status,
+	    gss_buffer_t output_token)
+{
+	NegTokenResp resp;
+	OM_uint32 ret;
+
+	resp.negState = malloc(sizeof(*resp.negState));
+	if (resp.negState == NULL) {
+		*minor_status = ENOMEM;
+		return (GSS_S_FAILURE);
+	}
+	*(resp.negState) = reject;
+
+	resp.supportedMech = NULL;
+	resp.responseToken = NULL;
+	resp.mechListMIC = NULL;
+
+	ret = code_NegTokenArg(minor_status, &resp,
+			       (unsigned char **)&output_token->value,
+			       &output_token->length);
+	free_NegTokenResp(&resp);
+	if (ret)
+		return (ret);
+
+	return (GSS_S_BAD_MECH);
+}
+
+static OM_uint32
+send_accept(OM_uint32 * minor_status,
+	    gss_buffer_t output_token,
+	    gss_buffer_t mech_token,
+	    const gss_OID pref)
+{
+	NegTokenResp resp;
+	OM_uint32 ret;
+
+	memset(&resp, 0, sizeof(resp));
+	resp.negState = malloc(sizeof(*resp.negState));
+	if (resp.negState == NULL) {
+		*minor_status = ENOMEM;
+		return (GSS_S_FAILURE);
+	}
+	*(resp.negState) = accept_completed;
+
+	resp.supportedMech = malloc(sizeof(*resp.supportedMech));
+	if (resp.supportedMech == NULL) {
+		free_NegTokenResp(&resp);
+		*minor_status = ENOMEM;
+		return (GSS_S_FAILURE);
+	}
+	ret = der_get_oid(pref->elements,
+			  pref->length,
+			  resp.supportedMech,
+			  NULL);
+	if (ret) {
+		free_NegTokenResp(&resp);
+		*minor_status = ENOMEM;
+		return (GSS_S_FAILURE);
+	}
+	if (mech_token != NULL && mech_token->length != 0U) {
+		resp.responseToken = malloc(sizeof(*resp.responseToken));
+		if (resp.responseToken == NULL) {
+			free_NegTokenResp(&resp);
+			*minor_status = ENOMEM;
+			return (GSS_S_FAILURE);
+		}
+		resp.responseToken->length = mech_token->length;
+		resp.responseToken->data = mech_token->value;
+	}
+
+	ret = code_NegTokenArg(minor_status, &resp,
+			       (unsigned char **)&output_token->value,
+			       &output_token->length);
+	if (resp.responseToken != NULL) {
+		free(resp.responseToken);
+		resp.responseToken = NULL;
+	}
+	free_NegTokenResp(&resp);
+	if (ret)
+		return (ret);
+
+	return (GSS_S_COMPLETE);
+}
+
+OM_uint32
+gss_accept_sec_context_spnego(OM_uint32 *minor_status,
+			      gss_ctx_id_t *context_handle,
+			      const gss_cred_id_t acceptor_cred_handle,
+			      const gss_buffer_t input_token_buffer,
+			      const gss_channel_bindings_t input_chan_bindings,
+			      gss_name_t *src_name,
+			      gss_OID *mech_type,
+			      gss_buffer_t output_token,
+			      OM_uint32 *ret_flags,
+			      OM_uint32 *time_rec,
+			      gss_cred_id_t *delegated_cred_handle)
+{
+	NegTokenInit init_token;
+	OM_uint32 major_status = GSS_S_COMPLETE;
+	OM_uint32 minor_status2;
+	gss_buffer_desc ibuf, obuf;
+	gss_buffer_t ot = NULL;
+	gss_OID pref = GSS_KRB5_MECH;
+	unsigned char *buf;
+	size_t buf_size;
+	size_t len, taglen, ni_len;
+	int found = 0;
+	int ret;
+	unsigned i;
+
+	/*
+	 * Before doing anything else, see whether this is a SPNEGO
+	 * PDU.  If not, dispatch to the GSSAPI library and get out.
+	 */
+
+	if (cmp_gss_type(input_token_buffer, GSS_SPNEGO_MECH))
+		return (gss_accept_sec_context(minor_status,
+					       context_handle,
+					       acceptor_cred_handle,
+					       input_token_buffer,
+					       input_chan_bindings,
+					       src_name,
+					       mech_type,
+					       output_token,
+					       ret_flags,
+					       time_rec,
+					       delegated_cred_handle));
+
+	/*
+	 * If we get here, it's SPNEGO.
+	 */
+
+	memset(&init_token, 0, sizeof(init_token));
+
+	ret = gssapi_spnego_decapsulate(minor_status, input_token_buffer,
+					&buf, &buf_size, GSS_SPNEGO_MECH);
+	if (ret)
+		return (ret);
+
+	ret = der_match_tag_and_length(buf, buf_size, ASN1_C_CONTEXT, CONS,
+				       0, &len, &taglen);
+	if (ret)
+		return (ret);
+
+	ret = decode_NegTokenInit(buf + taglen, len, &init_token, &ni_len);
+	if (ret) {
+		*minor_status = EINVAL;	/* XXX */
+		return (GSS_S_DEFECTIVE_TOKEN);
+	}
+
+	for (i = 0; !found && i < init_token.mechTypes.len; ++i) {
+		unsigned char mechbuf[17];
+		size_t mech_len;
+
+		ret = der_put_oid(mechbuf + sizeof(mechbuf) - 1,
+				  sizeof(mechbuf),
+				  &init_token.mechTypes.val[i],
+				  &mech_len);
+		if (ret) {
+			free_NegTokenInit(&init_token);
+			return (GSS_S_DEFECTIVE_TOKEN);
+		}
+		if (mech_len == GSS_KRB5_MECH->length &&
+		    isc_safe_memequal(GSS_KRB5_MECH->elements,
+				      mechbuf + sizeof(mechbuf) - mech_len,
+				      mech_len))
+		{
+			found = 1;
+			break;
+		}
+		if (mech_len == GSS_MSKRB5_MECH->length &&
+		    isc_safe_memequal(GSS_MSKRB5_MECH->elements,
+				      mechbuf + sizeof(mechbuf) - mech_len,
+				      mech_len))
+		{
+			found = 1;
+			if (i == 0)
+				pref = GSS_MSKRB5_MECH;
+			break;
+		}
+	}
+
+	if (!found) {
+		free_NegTokenInit(&init_token);
+		return (send_reject(minor_status, output_token));
+	}
+
+	if (i == 0 && init_token.mechToken != NULL) {
+		ibuf.length = init_token.mechToken->length;
+		ibuf.value = init_token.mechToken->data;
+
+		major_status = gss_accept_sec_context(minor_status,
+						      context_handle,
+						      acceptor_cred_handle,
+						      &ibuf,
+						      input_chan_bindings,
+						      src_name,
+						      mech_type,
+						      &obuf,
+						      ret_flags,
+						      time_rec,
+						      delegated_cred_handle);
+		if (GSS_ERROR(major_status)) {
+			free_NegTokenInit(&init_token);
+			send_reject(&minor_status2, output_token);
+			return (major_status);
+		}
+		ot = &obuf;
+	}
+	ret = send_accept(&minor_status2, output_token, ot, pref);
+	free_NegTokenInit(&init_token);
+	if (ot != NULL && ot->length != 0U)
+		gss_release_buffer(&minor_status2, ot);
+
+	return (ret != GSS_S_COMPLETE ? (OM_uint32) ret : major_status);
+}
+
+/* decapsulate.c */
+
+static OM_uint32
+gssapi_verify_mech_header(u_char ** str,
+			  size_t total_len,
+			  const gss_OID mech)
+{
+	size_t len, len_len, mech_len, foo;
+	int e;
+	u_char *p = *str;
+
+	if (total_len < 1U)
+		return (GSS_S_DEFECTIVE_TOKEN);
+	if (*p++ != 0x60)
+		return (GSS_S_DEFECTIVE_TOKEN);
+	e = der_get_length(p, total_len - 1, &len, &len_len);
+	if (e || 1 + len_len + len != total_len)
+		return (GSS_S_DEFECTIVE_TOKEN);
+	p += len_len;
+	if (*p++ != 0x06)
+		return (GSS_S_DEFECTIVE_TOKEN);
+	e = der_get_length(p, total_len - 1 - len_len - 1,
+			   &mech_len, &foo);
+	if (e)
+		return (GSS_S_DEFECTIVE_TOKEN);
+	p += foo;
+	if (mech_len != mech->length)
+		return (GSS_S_BAD_MECH);
+	if (!isc_safe_memequal(p, mech->elements, mech->length))
+		return (GSS_S_BAD_MECH);
+	p += mech_len;
+	*str = p;
+	return (GSS_S_COMPLETE);
+}
+
+/*
+ * Remove the GSS-API wrapping from `in_token' giving `buf and buf_size' Does
+ * not copy data, so just free `in_token'.
+ */
+
+static OM_uint32
+gssapi_spnego_decapsulate(OM_uint32 *minor_status,
+			  gss_buffer_t input_token_buffer,
+			  unsigned char **buf,
+			  size_t *buf_len,
+			  const gss_OID mech)
+{
+	u_char *p;
+	OM_uint32 ret;
+
+	p = input_token_buffer->value;
+	ret = gssapi_verify_mech_header(&p,
+					input_token_buffer->length,
+					mech);
+	if (ret) {
+		*minor_status = ret;
+		return (GSS_S_FAILURE);
+	}
+	*buf_len = input_token_buffer->length -
+		(p - (u_char *) input_token_buffer->value);
+	*buf = p;
+	return (GSS_S_COMPLETE);
+}
+
+/* der_free.c */
+
+static void
+free_octet_string(octet_string *k)
+{
+	free(k->data);
+	k->data = NULL;
+}
+
+static void
+free_oid(oid *k)
+{
+	free(k->components);
+	k->components = NULL;
+}
+
+/* der_get.c */
+
+/*
+ * All decoding functions take a pointer `p' to first position in which to
+ * read, from the left, `len' which means the maximum number of characters we
+ * are able to read, `ret' were the value will be returned and `size' where
+ * the number of used bytes is stored. Either 0 or an error code is returned.
+ */
+
+static int
+der_get_unsigned(const unsigned char *p, size_t len,
+		 unsigned *ret, size_t *size)
+{
+	unsigned val = 0;
+	size_t oldlen = len;
+
+	while (len--)
+		val = val * 256 + *p++;
+	*ret = val;
+	if (size)
+		*size = oldlen;
+	return (0);
+}
+
+static int
+der_get_int(const unsigned char *p, size_t len,
+	    int *ret, size_t *size)
+{
+	int val = 0;
+	size_t oldlen = len;
+
+	if (len > 0U) {
+		val = (signed char)*p++;
+		while (--len)
+			val = val * 256 + *p++;
+	}
+	*ret = val;
+	if (size)
+		*size = oldlen;
+	return (0);
+}
+
+static int
+der_get_length(const unsigned char *p, size_t len,
+	       size_t *val, size_t *size)
+{
+	size_t v;
+
+	if (len <= 0U)
+		return (ASN1_OVERRUN);
+	--len;
+	v = *p++;
+	if (v < 128U) {
+		*val = v;
+		if (size)
+			*size = 1;
+	} else {
+		int e;
+		size_t l;
+		unsigned tmp;
+
+		if (v == 0x80U) {
+			*val = ASN1_INDEFINITE;
+			if (size)
+				*size = 1;
+			return (0);
+		}
+		v &= 0x7F;
+		if (len < v)
+			return (ASN1_OVERRUN);
+		e = der_get_unsigned(p, v, &tmp, &l);
+		if (e)
+			return (e);
+		*val = tmp;
+		if (size)
+			*size = l + 1;
+	}
+	return (0);
+}
+
+static int
+der_get_octet_string(const unsigned char *p, size_t len,
+		     octet_string *data, size_t *size)
+{
+	data->length = len;
+	if (len != 0U) {
+		data->data = malloc(len);
+		if (data->data == NULL)
+			return (ENOMEM);
+		memmove(data->data, p, len);
+	} else
+		data->data = NULL;
+	if (size)
+		*size = len;
+	return (0);
+}
+
+static int
+der_get_oid(const unsigned char *p, size_t len, oid *data, size_t *size) {
+	int n;
+	size_t oldlen = len;
+
+	data->components = NULL;
+	data->length = 0;
+	if (len < 1U) {
+		return (ASN1_OVERRUN);
+	}
+
+	data->components = malloc(len * sizeof(*data->components));
+	if (data->components == NULL) {
+		return (ENOMEM);
+	}
+	data->components[0] = (*p) / 40;
+	data->components[1] = (*p) % 40;
+	--len;
+	++p;
+	for (n = 2; len > 0U; ++n) {
+		unsigned u = 0;
+
+		do {
+			--len;
+			u = u * 128 + (*p++ % 128);
+		} while (len > 0U && p[-1] & 0x80);
+		data->components[n] = u;
+	}
+	if (p[-1] & 0x80) {
+		free_oid(data);
+		return (ASN1_OVERRUN);
+	}
+	data->length = n;
+	if (size) {
+		*size = oldlen;
+	}
+	return (0);
+}
+
+static int
+der_get_tag(const unsigned char *p, size_t len,
+	    Der_class *xclass, Der_type *type,
+	    int *tag, size_t *size)
+{
+	if (len < 1U)
+		return (ASN1_OVERRUN);
+	*xclass = (Der_class) (((*p) >> 6) & 0x03);
+	*type = (Der_type) (((*p) >> 5) & 0x01);
+	*tag = (*p) & 0x1F;
+	if (size)
+		*size = 1;
+	return (0);
+}
+
+static int
+der_match_tag(const unsigned char *p, size_t len,
+	      Der_class xclass, Der_type type,
+	      int tag, size_t *size)
+{
+	size_t l;
+	Der_class thisclass;
+	Der_type thistype;
+	int thistag;
+	int e;
+
+	e = der_get_tag(p, len, &thisclass, &thistype, &thistag, &l);
+	if (e)
+		return (e);
+	if (xclass != thisclass || type != thistype)
+		return (ASN1_BAD_ID);
+	if (tag > thistag)
+		return (ASN1_MISPLACED_FIELD);
+	if (tag < thistag)
+		return (ASN1_MISSING_FIELD);
+	if (size)
+		*size = l;
+	return (0);
+}
+
+static int
+der_match_tag_and_length(const unsigned char *p, size_t len,
+			 Der_class xclass, Der_type type, int tag,
+			 size_t *length_ret, size_t *size)
+{
+	size_t l, ret = 0;
+	int e;
+
+	e = der_match_tag(p, len, xclass, type, tag, &l);
+	if (e)
+		return (e);
+	p += l;
+	len -= l;
+	ret += l;
+	e = der_get_length(p, len, length_ret, &l);
+	if (e)
+		return (e);
+	/* p += l; */
+	len -= l;
+	POST(len);
+	ret += l;
+	if (size)
+		*size = ret;
+	return (0);
+}
+
+static int
+decode_enumerated(const unsigned char *p, size_t len, void *num, size_t *size)
+{
+	size_t ret = 0;
+	size_t l, reallen;
+	int e;
+
+	e = der_match_tag(p, len, ASN1_C_UNIV, PRIM, UT_Enumerated, &l);
+	if (e)
+		return (e);
+	p += l;
+	len -= l;
+	ret += l;
+	e = der_get_length(p, len, &reallen, &l);
+	if (e)
+		return (e);
+	p += l;
+	len -= l;
+	ret += l;
+	e = der_get_int(p, reallen, num, &l);
+	if (e)
+		return (e);
+	p += l;
+	len -= l;
+	POST(p); POST(len);
+	ret += l;
+	if (size)
+		*size = ret;
+	return (0);
+}
+
+static int
+decode_octet_string(const unsigned char *p, size_t len,
+		    octet_string *k, size_t *size)
+{
+	size_t ret = 0;
+	size_t l;
+	int e;
+	size_t slen;
+
+	k->data = NULL;
+	k->length = 0;
+
+	e = der_match_tag(p, len, ASN1_C_UNIV, PRIM, UT_OctetString, &l);
+	if (e)
+		return (e);
+	p += l;
+	len -= l;
+	ret += l;
+
+	e = der_get_length(p, len, &slen, &l);
+	if (e)
+		return (e);
+	p += l;
+	len -= l;
+	ret += l;
+	if (len < slen)
+		return (ASN1_OVERRUN);
+
+	e = der_get_octet_string(p, slen, k, &l);
+	if (e)
+		return (e);
+	p += l;
+	len -= l;
+	POST(p); POST(len);
+	ret += l;
+	if (size)
+		*size = ret;
+	return (0);
+}
+
+static int
+decode_oid(const unsigned char *p, size_t len,
+	   oid *k, size_t *size)
+{
+	size_t ret = 0;
+	size_t l;
+	int e;
+	size_t slen;
+
+	e = der_match_tag(p, len, ASN1_C_UNIV, PRIM, UT_OID, &l);
+	if (e)
+		return (e);
+	p += l;
+	len -= l;
+	ret += l;
+
+	e = der_get_length(p, len, &slen, &l);
+	if (e)
+		return (e);
+	p += l;
+	len -= l;
+	ret += l;
+	if (len < slen)
+		return (ASN1_OVERRUN);
+
+	e = der_get_oid(p, slen, k, &l);
+	if (e)
+		return (e);
+	p += l;
+	len -= l;
+	POST(p); POST(len);
+	ret += l;
+	if (size)
+		*size = ret;
+	return (0);
+}
+
+static int
+fix_dce(size_t reallen, size_t *len)
+{
+	if (reallen == ASN1_INDEFINITE)
+		return (1);
+	if (*len < reallen)
+		return (-1);
+	*len = reallen;
+	return (0);
+}
+
+/* der_length.c */
+
+static size_t
+len_unsigned(unsigned val)
+{
+	size_t ret = 0;
+
+	do {
+		++ret;
+		val /= 256;
+	} while (val);
+	return (ret);
+}
+
+static size_t
+length_len(size_t len)
+{
+	if (len < 128U)
+		return (1);
+	else
+		return (len_unsigned((unsigned int)len) + 1);
+}
+
+
+/* der_put.c */
+
+/*
+ * All encoding functions take a pointer `p' to first position in which to
+ * write, from the right, `len' which means the maximum number of characters
+ * we are able to write.  The function returns the number of characters
+ * written in `size' (if non-NULL). The return value is 0 or an error.
+ */
+
+static int
+der_put_unsigned(unsigned char *p, size_t len, unsigned val, size_t *size)
+{
+	unsigned char *base = p;
+
+	if (val) {
+		while (len > 0U && val) {
+			*p-- = val % 256;
+			val /= 256;
+			--len;
+		}
+		if (val != 0)
+			return (ASN1_OVERFLOW);
+		else {
+			*size = base - p;
+			return (0);
+		}
+	} else if (len < 1U)
+		return (ASN1_OVERFLOW);
+	else {
+		*p = 0;
+		*size = 1;
+		return (0);
+	}
+}
+
+static int
+der_put_int(unsigned char *p, size_t len, int val, size_t *size)
+{
+	unsigned char *base = p;
+
+	if (val >= 0) {
+		do {
+			if (len < 1U)
+				return (ASN1_OVERFLOW);
+			*p-- = val % 256;
+			len--;
+			val /= 256;
+		} while (val);
+		if (p[1] >= 128) {
+			if (len < 1U)
+				return (ASN1_OVERFLOW);
+			*p-- = 0;
+			len--;
+			POST(len);
+		}
+	} else {
+		val = ~val;
+		do {
+			if (len < 1U)
+				return (ASN1_OVERFLOW);
+			*p-- = ~(val % 256);
+			len--;
+			val /= 256;
+		} while (val);
+		if (p[1] < 128) {
+			if (len < 1U)
+				return (ASN1_OVERFLOW);
+			*p-- = 0xff;
+			len--;
+			POST(len);
+		}
+	}
+	*size = base - p;
+	return (0);
+}
+
+static int
+der_put_length(unsigned char *p, size_t len, size_t val, size_t *size)
+{
+	if (len < 1U)
+		return (ASN1_OVERFLOW);
+	if (val < 128U) {
+		*p = (unsigned char)val;
+		*size = 1;
+		return (0);
+	} else {
+		size_t l;
+		int e;
+
+		e = der_put_unsigned(p, len - 1, (unsigned int)val, &l);
+		if (e)
+			return (e);
+		p -= l;
+		*p = 0x80 | (unsigned char)l;
+		*size = l + 1;
+		return (0);
+	}
+}
+
+static int
+der_put_octet_string(unsigned char *p, size_t len,
+		     const octet_string *data, size_t *size)
+{
+	if (len < data->length)
+		return (ASN1_OVERFLOW);
+	p -= data->length;
+	len -= data->length;
+	POST(len);
+	memmove(p + 1, data->data, data->length);
+	*size = data->length;
+	return (0);
+}
+
+static int
+der_put_oid(unsigned char *p, size_t len,
+	    const oid *data, size_t *size)
+{
+	unsigned char *base = p;
+	size_t n;
+
+	for (n = data->length; n >= 3u; --n) {
+		unsigned	u = data->components[n - 1];
+
+		if (len < 1U)
+			return (ASN1_OVERFLOW);
+		*p-- = u % 128;
+		u /= 128;
+		--len;
+		while (u > 0) {
+			if (len < 1U)
+				return (ASN1_OVERFLOW);
+			*p-- = 128 + u % 128;
+			u /= 128;
+			--len;
+		}
+	}
+	if (len < 1U)
+		return (ASN1_OVERFLOW);
+	*p-- = 40 * data->components[0] + data->components[1];
+	*size = base - p;
+	return (0);
+}
+
+static int
+der_put_tag(unsigned char *p, size_t len, Der_class xclass, Der_type type,
+	    int tag, size_t *size)
+{
+	if (len < 1U)
+		return (ASN1_OVERFLOW);
+	*p = (xclass << 6) | (type << 5) | tag;	/* XXX */
+	*size = 1;
+	return (0);
+}
+
+static int
+der_put_length_and_tag(unsigned char *p, size_t len, size_t len_val,
+		       Der_class xclass, Der_type type, int tag, size_t *size)
+{
+	size_t ret = 0;
+	size_t l;
+	int e;
+
+	e = der_put_length(p, len, len_val, &l);
+	if (e)
+		return (e);
+	p -= l;
+	len -= l;
+	ret += l;
+	e = der_put_tag(p, len, xclass, type, tag, &l);
+	if (e)
+		return (e);
+	p -= l;
+	len -= l;
+	POST(p); POST(len);
+	ret += l;
+	*size = ret;
+	return (0);
+}
+
+static int
+encode_enumerated(unsigned char *p, size_t len, const void *data, size_t *size)
+{
+	unsigned num = *(const unsigned *)data;
+	size_t ret = 0;
+	size_t l;
+	int e;
+
+	e = der_put_int(p, len, num, &l);
+	if (e)
+		return (e);
+	p -= l;
+	len -= l;
+	ret += l;
+	e = der_put_length_and_tag(p, len, l, ASN1_C_UNIV, PRIM, UT_Enumerated, &l);
+	if (e)
+		return (e);
+	p -= l;
+	len -= l;
+	POST(p); POST(len);
+	ret += l;
+	*size = ret;
+	return (0);
+}
+
+static int
+encode_octet_string(unsigned char *p, size_t len,
+		    const octet_string *k, size_t *size)
+{
+	size_t ret = 0;
+	size_t l;
+	int e;
+
+	e = der_put_octet_string(p, len, k, &l);
+	if (e)
+		return (e);
+	p -= l;
+	len -= l;
+	ret += l;
+	e = der_put_length_and_tag(p, len, l, ASN1_C_UNIV, PRIM, UT_OctetString, &l);
+	if (e)
+		return (e);
+	p -= l;
+	len -= l;
+	POST(p); POST(len);
+	ret += l;
+	*size = ret;
+	return (0);
+}
+
+static int
+encode_oid(unsigned char *p, size_t len,
+	   const oid *k, size_t *size)
+{
+	size_t ret = 0;
+	size_t l;
+	int e;
+
+	e = der_put_oid(p, len, k, &l);
+	if (e)
+		return (e);
+	p -= l;
+	len -= l;
+	ret += l;
+	e = der_put_length_and_tag(p, len, l, ASN1_C_UNIV, PRIM, UT_OID, &l);
+	if (e)
+		return (e);
+	p -= l;
+	len -= l;
+	POST(p); POST(len);
+	ret += l;
+	*size = ret;
+	return (0);
+}
+
+
+/* encapsulate.c */
+
+static void
+gssapi_encap_length(size_t data_len,
+		    size_t *len,
+		    size_t *total_len,
+		    const gss_OID mech)
+{
+	size_t len_len;
+
+	*len = 1 + 1 + mech->length + data_len;
+
+	len_len = length_len(*len);
+
+	*total_len = 1 + len_len + *len;
+}
+
+static u_char *
+gssapi_mech_make_header(u_char *p,
+			size_t len,
+			const gss_OID mech)
+{
+	int e;
+	size_t len_len, foo;
+
+	*p++ = 0x60;
+	len_len = length_len(len);
+	e = der_put_length(p + len_len - 1, len_len, len, &foo);
+	if (e || foo != len_len)
+		return (NULL);
+	p += len_len;
+	*p++ = 0x06;
+	*p++ = mech->length;
+	memmove(p, mech->elements, mech->length);
+	p += mech->length;
+	return (p);
+}
+
+/*
+ * Give it a krb5_data and it will encapsulate with extra GSS-API wrappings.
+ */
+
+static OM_uint32
+gssapi_spnego_encapsulate(OM_uint32 * minor_status,
+			  unsigned char *buf,
+			  size_t buf_size,
+			  gss_buffer_t output_token,
+			  const gss_OID mech)
+{
+	size_t len, outer_len;
+	u_char *p;
+
+	gssapi_encap_length(buf_size, &len, &outer_len, mech);
+
+	output_token->length = outer_len;
+	output_token->value = malloc(outer_len);
+	if (output_token->value == NULL) {
+		*minor_status = ENOMEM;
+		return (GSS_S_FAILURE);
+	}
+	p = gssapi_mech_make_header(output_token->value, len, mech);
+	if (p == NULL) {
+		if (output_token->length != 0U)
+			gss_release_buffer(minor_status, output_token);
+		return (GSS_S_FAILURE);
+	}
+	memmove(p, buf, buf_size);
+	return (GSS_S_COMPLETE);
+}
+
+/* init_sec_context.c */
+/*
+ * SPNEGO wrapper for Kerberos5 GSS-API kouril@ics.muni.cz, 2003 (mostly
+ * based on Heimdal code)
+ */
+
+static int
+add_mech(MechTypeList * mech_list, gss_OID mech)
+{
+	MechType *tmp;
+	int ret;
+
+	tmp = realloc(mech_list->val, (mech_list->len + 1) * sizeof(*tmp));
+	if (tmp == NULL)
+		return (ENOMEM);
+	mech_list->val = tmp;
+
+	ret = der_get_oid(mech->elements, mech->length,
+			  &mech_list->val[mech_list->len], NULL);
+	if (ret)
+		return (ret);
+
+	mech_list->len++;
+	return (0);
+}
+
+/*
+ * return the length of the mechanism in token or -1
+ * (which implies that the token was bad - GSS_S_DEFECTIVE_TOKEN
+ */
+
+static ssize_t
+gssapi_krb5_get_mech(const u_char *ptr,
+		     size_t total_len,
+		     const u_char **mech_ret)
+{
+	size_t len, len_len, mech_len, foo;
+	const u_char *p = ptr;
+	int e;
+
+	if (total_len < 1U)
+		return (-1);
+	if (*p++ != 0x60)
+		return (-1);
+	e = der_get_length (p, total_len - 1, &len, &len_len);
+	if (e || 1 + len_len + len != total_len)
+		return (-1);
+	p += len_len;
+	if (*p++ != 0x06)
+		return (-1);
+	e = der_get_length (p, total_len - 1 - len_len - 1,
+			    &mech_len, &foo);
+	if (e)
+		return (-1);
+	p += foo;
+	*mech_ret = p;
+	return (mech_len);
+}
+
+static OM_uint32
+spnego_initial(OM_uint32 *minor_status,
+	       const gss_cred_id_t initiator_cred_handle,
+	       gss_ctx_id_t *context_handle,
+	       const gss_name_t target_name,
+	       const gss_OID mech_type,
+	       OM_uint32 req_flags,
+	       OM_uint32 time_req,
+	       const gss_channel_bindings_t input_chan_bindings,
+	       const gss_buffer_t input_token,
+	       gss_OID *actual_mech_type,
+	       gss_buffer_t output_token,
+	       OM_uint32 *ret_flags,
+	       OM_uint32 *time_rec)
+{
+	NegTokenInit token_init;
+	OM_uint32 major_status, minor_status2;
+	gss_buffer_desc	krb5_output_token = GSS_C_EMPTY_BUFFER;
+	unsigned char *buf = NULL;
+	size_t buf_size;
+	size_t len;
+	int ret;
+
+	(void)mech_type;
+
+	memset(&token_init, 0, sizeof(token_init));
+
+	ret = add_mech(&token_init.mechTypes, GSS_KRB5_MECH);
+	if (ret) {
+		*minor_status = ret;
+		ret = GSS_S_FAILURE;
+		goto end;
+	}
+
+	major_status = gss_init_sec_context(minor_status,
+					    initiator_cred_handle,
+					    context_handle,
+					    target_name,
+					    GSS_KRB5_MECH,
+					    req_flags,
+					    time_req,
+					    input_chan_bindings,
+					    input_token,
+					    actual_mech_type,
+					    &krb5_output_token,
+					    ret_flags,
+					    time_rec);
+	if (GSS_ERROR(major_status)) {
+		ret = major_status;
+		goto end;
+	}
+	if (krb5_output_token.length > 0U) {
+		token_init.mechToken = malloc(sizeof(*token_init.mechToken));
+		if (token_init.mechToken == NULL) {
+			*minor_status = ENOMEM;
+			ret = GSS_S_FAILURE;
+			goto end;
+		}
+		token_init.mechToken->data = krb5_output_token.value;
+		token_init.mechToken->length = krb5_output_token.length;
+	}
+	/*
+	 * The MS implementation of SPNEGO seems to not like the mechListMIC
+	 * field, so we omit it (it's optional anyway)
+	 */
+
+	buf_size = 1024;
+	buf = malloc(buf_size);
+	if (buf == NULL) {
+		*minor_status = ENOMEM;
+		ret = GSS_S_FAILURE;
+		goto end;
+	}
+
+	do {
+		ret = encode_NegTokenInit(buf + buf_size - 1,
+					  buf_size,
+					  &token_init, &len);
+		if (ret == 0) {
+			size_t tmp;
+
+			ret = der_put_length_and_tag(buf + buf_size - len - 1,
+						     buf_size - len,
+						     len,
+						     ASN1_C_CONTEXT,
+						     CONS,
+						     0,
+						     &tmp);
+			if (ret == 0)
+				len += tmp;
+		}
+		if (ret) {
+			if (ret == ASN1_OVERFLOW) {
+				u_char *tmp;
+
+				buf_size *= 2;
+				tmp = realloc(buf, buf_size);
+				if (tmp == NULL) {
+					*minor_status = ENOMEM;
+					ret = GSS_S_FAILURE;
+					goto end;
+				}
+				buf = tmp;
+			} else {
+				*minor_status = ret;
+				ret = GSS_S_FAILURE;
+				goto end;
+			}
+		}
+	} while (ret == ASN1_OVERFLOW);
+
+	ret = gssapi_spnego_encapsulate(minor_status,
+					buf + buf_size - len, len,
+					output_token, GSS_SPNEGO_MECH);
+	if (ret == GSS_S_COMPLETE)
+		ret = major_status;
+
+end:
+	if (token_init.mechToken != NULL) {
+		free(token_init.mechToken);
+		token_init.mechToken = NULL;
+	}
+	free_NegTokenInit(&token_init);
+	if (krb5_output_token.length != 0U)
+		gss_release_buffer(&minor_status2, &krb5_output_token);
+	if (buf)
+		free(buf);
+
+	return (ret);
+}
+
+static OM_uint32
+spnego_reply(OM_uint32 *minor_status,
+	     const gss_cred_id_t initiator_cred_handle,
+	     gss_ctx_id_t *context_handle,
+	     const gss_name_t target_name,
+	     const gss_OID mech_type,
+	     OM_uint32 req_flags,
+	     OM_uint32 time_req,
+	     const gss_channel_bindings_t input_chan_bindings,
+	     const gss_buffer_t input_token,
+	     gss_OID *actual_mech_type,
+	     gss_buffer_t output_token,
+	     OM_uint32 *ret_flags,
+	     OM_uint32 *time_rec)
+{
+	OM_uint32 ret;
+	NegTokenResp resp;
+	unsigned char *buf;
+	size_t buf_size;
+	u_char oidbuf[17];
+	size_t oidlen;
+	gss_buffer_desc sub_token;
+	ssize_t mech_len;
+	const u_char *p;
+	size_t len, taglen;
+
+	(void)mech_type;
+
+	output_token->length = 0;
+	output_token->value  = NULL;
+
+	/*
+	 * SPNEGO doesn't include gss wrapping on SubsequentContextToken
+	 * like the Kerberos 5 mech does. But lets check for it anyway.
+	 */
+
+	mech_len = gssapi_krb5_get_mech(input_token->value,
+					input_token->length,
+					&p);
+
+	if (mech_len < 0) {
+		buf = input_token->value;
+		buf_size = input_token->length;
+	} else if ((size_t)mech_len == GSS_KRB5_MECH->length &&
+		   isc_safe_memequal(GSS_KRB5_MECH->elements, p, mech_len))
+		return (gss_init_sec_context(minor_status,
+					     initiator_cred_handle,
+					     context_handle,
+					     target_name,
+					     GSS_KRB5_MECH,
+					     req_flags,
+					     time_req,
+					     input_chan_bindings,
+					     input_token,
+					     actual_mech_type,
+					     output_token,
+					     ret_flags,
+					     time_rec));
+	else if ((size_t)mech_len == GSS_SPNEGO_MECH->length &&
+		 isc_safe_memequal(GSS_SPNEGO_MECH->elements, p, mech_len)) {
+		ret = gssapi_spnego_decapsulate(minor_status,
+						input_token,
+						&buf,
+						&buf_size,
+						GSS_SPNEGO_MECH);
+		if (ret)
+			return (ret);
+	} else
+		return (GSS_S_BAD_MECH);
+
+	ret = der_match_tag_and_length(buf, buf_size,
+				       ASN1_C_CONTEXT, CONS, 1, &len, &taglen);
+	if (ret)
+		return (ret);
+
+	if(len > buf_size - taglen)
+		return (ASN1_OVERRUN);
+
+	ret = decode_NegTokenResp(buf + taglen, len, &resp, NULL);
+	if (ret) {
+		free_NegTokenResp(&resp);
+		*minor_status = ENOMEM;
+		return (GSS_S_FAILURE);
+	}
+
+	if (resp.negState == NULL ||
+	    *(resp.negState) == reject ||
+	    resp.supportedMech == NULL) {
+		free_NegTokenResp(&resp);
+		return (GSS_S_BAD_MECH);
+	}
+
+	ret = der_put_oid(oidbuf + sizeof(oidbuf) - 1,
+			  sizeof(oidbuf),
+			  resp.supportedMech,
+			  &oidlen);
+	if (ret || oidlen != GSS_KRB5_MECH->length ||
+	    !isc_safe_memequal(oidbuf + sizeof(oidbuf) - oidlen,
+			      GSS_KRB5_MECH->elements, oidlen))
+	{
+		free_NegTokenResp(&resp);
+		return GSS_S_BAD_MECH;
+	}
+
+	if (resp.responseToken != NULL) {
+		sub_token.length = resp.responseToken->length;
+		sub_token.value  = resp.responseToken->data;
+	} else {
+		sub_token.length = 0;
+		sub_token.value  = NULL;
+	}
+
+	ret = gss_init_sec_context(minor_status,
+				   initiator_cred_handle,
+				   context_handle,
+				   target_name,
+				   GSS_KRB5_MECH,
+				   req_flags,
+				   time_req,
+				   input_chan_bindings,
+				   &sub_token,
+				   actual_mech_type,
+				   output_token,
+				   ret_flags,
+				   time_rec);
+	if (ret) {
+		free_NegTokenResp(&resp);
+		return (ret);
+	}
+
+	/*
+	 * XXXSRA I don't think this limited implementation ever needs
+	 * to check the MIC -- our preferred mechanism (Kerberos)
+	 * authenticates its own messages and is the only mechanism
+	 * we'll accept, so if the mechanism negotiation completes
+	 * successfully, we don't need the MIC.  See RFC 4178.
+	 */
+
+	free_NegTokenResp(&resp);
+	return (ret);
+}
+
+
+
+OM_uint32
+gss_init_sec_context_spnego(OM_uint32 *minor_status,
+			    const gss_cred_id_t initiator_cred_handle,
+			    gss_ctx_id_t *context_handle,
+			    const gss_name_t target_name,
+			    const gss_OID mech_type,
+			    OM_uint32 req_flags,
+			    OM_uint32 time_req,
+			    const gss_channel_bindings_t input_chan_bindings,
+			    const gss_buffer_t input_token,
+			    gss_OID *actual_mech_type,
+			    gss_buffer_t output_token,
+			    OM_uint32 *ret_flags,
+			    OM_uint32 *time_rec)
+{
+	/* Dirty trick to suppress compiler warnings */
+
+	/* Figure out whether we're starting over or processing a reply */
+
+	if (input_token == GSS_C_NO_BUFFER || input_token->length == 0U)
+		return (spnego_initial(minor_status,
+				       initiator_cred_handle,
+				       context_handle,
+				       target_name,
+				       mech_type,
+				       req_flags,
+				       time_req,
+				       input_chan_bindings,
+				       input_token,
+				       actual_mech_type,
+				       output_token,
+				       ret_flags,
+				       time_rec));
+	else
+		return (spnego_reply(minor_status,
+				     initiator_cred_handle,
+				     context_handle,
+				     target_name,
+				     mech_type,
+				     req_flags,
+				     time_req,
+				     input_chan_bindings,
+				     input_token,
+				     actual_mech_type,
+				     output_token,
+				     ret_flags,
+				     time_rec));
+}
+
+#endif /* GSSAPI */