krb5/mech/k5unseal.c

	k5unseal.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Copyright 1993 by OpenVision Technologies, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appears in all copies and
 * that both that copyright notice and this permission notice appear in
 * supporting documentation, and that the name of OpenVision not be used
 * in advertising or publicity pertaining to distribution of the software
 * without specific, written prior permission. OpenVision makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * Copyright (C) 1998 by the FundsXpress, INC.
 *
 * All rights reserved.
 *
 * Export of this software from the United States of America may require
 * a specific license from the United States Government.  It is the
 * responsibility of any person or organization contemplating export to
 * obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of FundsXpress. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  FundsXpress makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <gssapiP_krb5.h>
#include <k5-int.h>

/*
 * $Id: k5unseal.c,v 1.19.6.2 2000/05/31 17:17:38 raeburn Exp $
 */

/* message_buffer is an input if SIGN, output if SEAL, and ignored if DEL_CTX
   conf_state is only valid if SEAL.
   */

OM_uint32
kg_unseal_v1(context, minor_status, ctx, ptr, bodysize, message_buffer,
         conf_state, qop_state, toktype)
    krb5_context context;
    OM_uint32 *minor_status;
    krb5_gss_ctx_id_rec *ctx;
    unsigned char *ptr;
    int bodysize;
    gss_buffer_t message_buffer;
    int *conf_state;
    int *qop_state;
    int toktype;
{
    krb5_error_code code;
    int conflen = 0;
    int signalg;
    int sealalg;
    gss_buffer_desc token;
    krb5_checksum cksum;
    krb5_checksum md5cksum;
    krb5_data plaind;
    char *data_ptr;
    krb5_timestamp now;
    unsigned char *plain;
    int cksum_len = 0;
    int plainlen;
    int direction;
    krb5_ui_4 seqnum;
    OM_uint32 retval;
    size_t sumlen;
    int tmsglen;
    krb5_keyusage sign_usage = KG_USAGE_SIGN;

    KRB5_LOG0(KRB5_INFO, "kg_unseal_v1() start\n");

    /* Solaris Kerberos:  make sure this is initialized */
    *minor_status = 0;

    if (toktype == KG_TOK_SEAL_MSG) {
    message_buffer->length = 0;
    message_buffer->value = NULL;
    }

    /* get the sign and seal algorithms */

    signalg = ptr[0] + (ptr[1]<<8);
    sealalg = ptr[2] + (ptr[3]<<8);

    /* Sanity checks */

    if ((ptr[4] != 0xff) || (ptr[5] != 0xff)) {
    *minor_status = 0;
    KRB5_LOG0(KRB5_ERR, "kg_unseal_v1() end, error GSS_S_DEFECTIVE_TOKEN\n");
    return GSS_S_DEFECTIVE_TOKEN;
    }

    if ((toktype != KG_TOK_SEAL_MSG) &&
    (sealalg != 0xffff)) {
    *minor_status = 0;
    KRB5_LOG0(KRB5_ERR, "kg_unseal_v1() end, error2 GSS_S_DEFECTIVE_TOKEN\n");
    return GSS_S_DEFECTIVE_TOKEN;
    }

    /* in the current spec, there is only one valid seal algorithm per
       key type, so a simple comparison is ok */

    if ((toktype == KG_TOK_SEAL_MSG) &&
    !((sealalg == 0xffff) ||
      (sealalg == ctx->sealalg))) {
    *minor_status = 0;
    KRB5_LOG0(KRB5_ERR, "kg_unseal_v1() end, error3 GSS_S_DEFECTIVE_TOKEN\n");
    return GSS_S_DEFECTIVE_TOKEN;
    }

    /* there are several mappings of seal algorithms to sign algorithms,
       but few enough that we can try them all. */

    if ((ctx->sealalg == SEAL_ALG_NONE && signalg > 1) ||
    (ctx->sealalg == SEAL_ALG_1 && signalg != SGN_ALG_3)  ||
    (ctx->sealalg == SEAL_ALG_DES3KD &&
     signalg != SGN_ALG_HMAC_SHA1_DES3_KD) ||
    (ctx->sealalg == SEAL_ALG_MICROSOFT_RC4 &&
     signalg != SGN_ALG_HMAC_MD5)) {
    *minor_status = 0;
    KRB5_LOG0(KRB5_ERR, "kg_unseal_v1() end, error4 GSS_S_DEFECTIVE_TOKEN\n");
    return GSS_S_DEFECTIVE_TOKEN;
    }

    KRB5_LOG(KRB5_INFO, "kg_unseal_v1() signalg = %d\n", signalg);

    switch (signalg) {
    case SGN_ALG_DES_MAC_MD5:
    case SGN_ALG_MD2_5:
    case SGN_ALG_HMAC_MD5:
    cksum_len = 8;
    if (toktype != KG_TOK_SEAL_MSG)
      sign_usage = 15;
    break;
    case SGN_ALG_3:
    cksum_len = 16;
    break;
    case SGN_ALG_HMAC_SHA1_DES3_KD:
    cksum_len = 20;
    break;
    default:
    *minor_status = 0;
    KRB5_LOG(KRB5_ERR, "kg_unseal_v1() end, error signalg=%d\n", signalg);
    return GSS_S_DEFECTIVE_TOKEN;
    }

#ifdef _KERNEL
    /*
     * Because the ARCFOUR code bypasses the standard
     * crypto interfaces, we must make sure the kernel
     * crypto framework mechanism types are properly
     * initialized here.
     */
    context->kef_cipher_mt = get_cipher_mech_type(context,
                    ctx->seq);
    context->kef_hash_mt = get_hash_mech_type(context,
                    ctx->seq);
    if ((code = init_key_kef(context->kef_cipher_mt,
                ctx->seq))) {
        *minor_status = code;
        return (GSS_S_FAILURE);
    }
    if ((code = init_key_kef(context->kef_cipher_mt,
            ctx->enc))) {
        *minor_status = code;
        return (GSS_S_FAILURE);
    }
#endif /* _KERNEL */

    /* get the token parameters */
    if ((code = kg_get_seq_num(context, ctx->seq, ptr+14, ptr+6, &direction,
    &seqnum))) {
    *minor_status = code;
    return(GSS_S_BAD_SIG);
    }

    /* decode the message, if SEAL */

    if (toktype == KG_TOK_SEAL_MSG) {
    tmsglen = bodysize-(14+cksum_len);
    KRB5_LOG1(KRB5_INFO, "kg_unseal_v1() tmsglen = %d cksum_len = %d",
        tmsglen, cksum_len);
    KRB5_LOG0(KRB5_INFO, "kg_unseal_v1() toktype == KG_TOK_SEAL_MSG\n");

    if (sealalg != 0xffff) {
        if ((plain = (unsigned char *) xmalloc(tmsglen)) == NULL) {
        *minor_status = ENOMEM;
        KRB5_LOG0(KRB5_ERR, "kg_unseal_v1() end, error ENOMEM\n");
        return(GSS_S_FAILURE);
        }
            if (ctx->enc->enctype == ENCTYPE_ARCFOUR_HMAC) {
        unsigned char bigend_seqnum[4];
        krb5_keyblock *enc_key;
        int i;

        bigend_seqnum[0] = (seqnum>>24) & 0xff;
        bigend_seqnum[1] = (seqnum>>16) & 0xff;
        bigend_seqnum[2] = (seqnum>>8) & 0xff;
        bigend_seqnum[3] = seqnum & 0xff;
        code = krb5_copy_keyblock (context, ctx->enc, &enc_key);
        if (code)
        {
                  xfree_wrap(plain, tmsglen);
          *minor_status = code;
          return(GSS_S_FAILURE);
        }

        for (i = 0; i <= 15; i++)
            ((char *) enc_key->contents)[i] ^=0xf0;

#ifndef _KERNEL
        /*
         * The enc_key contents were modified, delete the
         * key object so it doesn't get used later.
         */
        if (enc_key->hKey != CK_INVALID_HANDLE) {
            (void)C_DestroyObject(krb_ctx_hSession(context),
                enc_key->hKey);
            enc_key->hKey = CK_INVALID_HANDLE;
        }
#endif
        KRB5_LOG(KRB5_INFO, "kg_unseal_v1() enc_key->enctype = %d",
            enc_key->enctype);

        code = kg_arcfour_docrypt (context,
                enc_key, 0,
                &bigend_seqnum[0], 4,
                ptr+14+cksum_len, tmsglen,
                plain);
        krb5_free_keyblock (context, enc_key);
            } else {
        code = kg_decrypt(context, ctx->enc, KG_USAGE_SEAL, NULL,
            ptr+14+cksum_len, plain, tmsglen);
        }
            if (code) {
                xfree_wrap(plain, tmsglen);
        *minor_status = code;
        return(GSS_S_FAILURE);
            }
    } else {
        plain = ptr+14+cksum_len;
    }

    plainlen = tmsglen;

    if ((sealalg == 0xffff) && ctx->big_endian) {
        token.length = tmsglen;
    } else {
        conflen = kg_confounder_size(context, ctx->enc);
        token.length = tmsglen - conflen - plain[tmsglen-1];
    }

    if (token.length) {
        if ((token.value = (void *) xmalloc(token.length)) == NULL) {
        if (sealalg != 0xffff)
            xfree_wrap(plain, tmsglen);
        *minor_status = ENOMEM;
        KRB5_LOG0(KRB5_ERR, "kg_unseal_v1() end, error2 ENOMEM\n");
        return(GSS_S_FAILURE);
        }
        (void) memcpy(token.value, plain+conflen, token.length);
    } else {
        token.value = NULL;
    }
    } else if (toktype == KG_TOK_SIGN_MSG) {
    KRB5_LOG0(KRB5_INFO, "kg_unseal_v1() toktype == KG_TOK_SIGN_MSG\n");
    token = *message_buffer;
    plain = token.value;
    plainlen = token.length;
    } else {
    KRB5_LOG0(KRB5_INFO, "kg_unseal_v1() toktype == NULL\n");
    token.length = 0;
    token.value = NULL;
    plain = token.value;
    plainlen = token.length;
    }

    /* compute the checksum of the message */

    /* initialize the the cksum */
    switch (signalg) {
    case SGN_ALG_DES_MAC_MD5:
    case SGN_ALG_MD2_5:
    case SGN_ALG_DES_MAC:
    case SGN_ALG_3:
    md5cksum.checksum_type = CKSUMTYPE_RSA_MD5;
    break;
    case SGN_ALG_HMAC_SHA1_DES3_KD:
    md5cksum.checksum_type = CKSUMTYPE_HMAC_SHA1_DES3;
    break;
    case SGN_ALG_HMAC_MD5:
    md5cksum.checksum_type = CKSUMTYPE_HMAC_MD5_ARCFOUR;
    break;
    default:
    KRB5_LOG(KRB5_ERR, "kg_unseal_v1() end, error2 signalg=%d\n", signalg);
#ifndef _KERNEL
    abort ();
#else
    *minor_status = 0;
    return(GSS_S_DEFECTIVE_TOKEN);
#endif /* _KERNEL */
    }

    if (code = krb5_c_checksum_length(context, md5cksum.checksum_type,
        &sumlen))
    {
    KRB5_LOG(KRB5_ERR, "kg_unseal_v1() end, krb5_c_checksum_length() error "
        "code=%d\n", code);
    return(code);
    }
    md5cksum.length = (size_t)sumlen;

    switch (signalg) {
    case SGN_ALG_DES_MAC_MD5:
    case SGN_ALG_3:
    /* compute the checksum of the message */

    /* 8 = bytes of token body to be checksummed according to spec */

    if (! (data_ptr = (void *)
           xmalloc(8 + (ctx->big_endian ? token.length : plainlen)))) {
        if (sealalg != 0xffff)
        xfree_wrap(plain, tmsglen);
        if (toktype == KG_TOK_SEAL_MSG) {
        xfree_wrap(token.value, token.length);
        /* Solaris Kerberos: just to be safe since token.value is an
         * output parameter.
         */
        token.value = NULL;
        token.length = 0;
        }
        *minor_status = ENOMEM;
        KRB5_LOG0(KRB5_ERR, "kg_unseal_v1() end, error3 ENOMEM\n");
        return(GSS_S_FAILURE);
    }

    (void) memcpy(data_ptr, ptr-2, 8);

    if (ctx->big_endian)
        (void) memcpy(data_ptr+8, token.value, token.length);
    else
        (void) memcpy(data_ptr+8, plain, plainlen);

    plaind.length = 8 + (ctx->big_endian ? token.length : plainlen);
    plaind.data = data_ptr;
    code = krb5_c_make_checksum(context, md5cksum.checksum_type,
                    ctx->seq, sign_usage,
                    &plaind, &md5cksum);
    xfree_wrap(data_ptr, 8 + (ctx->big_endian ? token.length : plainlen));

    if (code) {
        if (toktype == KG_TOK_SEAL_MSG) {
        xfree_wrap(token.value, token.length);
        /* Solaris Kerberos: just to be safe since token.value is an
         * output parameter.
         */
        token.value = NULL;
        token.length = 0;
        }
        *minor_status = code;
        KRB5_LOG(KRB5_ERR, "kg_unseal_v1() end, krb5_c_make_checksum() "
            "error code = %d\n", code);
        return(GSS_S_FAILURE);
    }

    if ((code = kg_encrypt(context, ctx->seq, KG_USAGE_SEAL,
                   (g_OID_equal(&ctx->mech_used, gss_mech_krb5_old) ?
                ctx->seq->contents : NULL),
                   md5cksum.contents, md5cksum.contents, 16))) {
        xfree_wrap(md5cksum.contents, md5cksum.length);
        if (toktype == KG_TOK_SEAL_MSG) {
        xfree_wrap(token.value, token.length);
        /* Solaris Kerberos: just to be safe since token.value is an
         * output parameter.
         */
        token.value = NULL;
        token.length = 0;
        }
        *minor_status = code;
        KRB5_LOG(KRB5_ERR, "kg_unseal_v1() end, kg_encrypt() error"
            "code = %d\n", code);
        return GSS_S_FAILURE;
    }

    if (signalg == 0)
        cksum.length = 8;
    else
        cksum.length = 16;
    cksum.contents = md5cksum.contents + 16 - cksum.length;

    code = memcmp(cksum.contents, ptr+14, cksum.length);
    break;

    case SGN_ALG_MD2_5:
    if (!ctx->seed_init &&
        (code = kg_make_seed(context, ctx->subkey, ctx->seed))) {
        xfree_wrap(md5cksum.contents, md5cksum.length);
        if (sealalg != 0xffff)
        xfree_wrap(plain, tmsglen);
        if (toktype == KG_TOK_SEAL_MSG) {
        xfree_wrap(token.value, token.length);
        /* Solaris Kerberos: just to be safe since token.value is an
         * output parameter.
         */
        token.value = NULL;
        token.length = 0;
        }
        *minor_status = code;
        return GSS_S_FAILURE;
    }

    if (! (data_ptr = (void *)
           xmalloc(sizeof(ctx->seed) + 8 +
               (ctx->big_endian ? token.length : plainlen)))) {
        xfree_wrap(md5cksum.contents, md5cksum.length);
        if (sealalg == 0)
        xfree_wrap(plain, tmsglen);
        if (toktype == KG_TOK_SEAL_MSG) {
        xfree_wrap(token.value, token.length);
        /* Solaris Kerberos: just to be safe since token.value is an
         * output parameter.
         */
        token.value = NULL;
        token.length = 0;
        }
        *minor_status = ENOMEM;
        return(GSS_S_FAILURE);
    }
    (void) memcpy(data_ptr, ptr-2, 8);
    (void) memcpy(data_ptr+8, ctx->seed, sizeof(ctx->seed));
    if (ctx->big_endian)
        (void) memcpy(data_ptr+8+sizeof(ctx->seed),
              token.value, token.length);
    else
        (void) memcpy(data_ptr+8+sizeof(ctx->seed),
              plain, plainlen);
    plaind.length = 8 + sizeof(ctx->seed) +
        (ctx->big_endian ? token.length : plainlen);
    plaind.data = data_ptr;
    xfree_wrap(md5cksum.contents, md5cksum.length);
    code = krb5_c_make_checksum(context, md5cksum.checksum_type,
                    ctx->seq, KG_USAGE_SIGN,
                    &plaind, &md5cksum);
    xfree_wrap(data_ptr, 8 + sizeof(ctx->seed) +
            (ctx->big_endian ? token.length : plainlen));

    if (code) {
        if (sealalg == 0)
        xfree_wrap(plain, tmsglen);
        if (toktype == KG_TOK_SEAL_MSG) {
        xfree_wrap(token.value, token.length);
        /* Solaris Kerberos: just to be safe since token.value is an
         * output parameter.
         */
        token.value = NULL;
        token.length = 0;
        }
        *minor_status = code;
        return(GSS_S_FAILURE);
    }

    code = memcmp(md5cksum.contents, ptr+14, 8);
    /* Falls through to defective-token??  */

    default:
    *minor_status = 0;
    KRB5_LOG0(KRB5_ERR, "kg_unseal_v1() end, error SGN_ALG_MD2_5 "
        "GSS_S_DEFECTIVE_TOKEN\n");
    return(GSS_S_DEFECTIVE_TOKEN);

    case SGN_ALG_HMAC_SHA1_DES3_KD:
    case SGN_ALG_HMAC_MD5:
    /* compute the checksum of the message */

    /* 8 = bytes of token body to be checksummed according to spec */

    if (! (data_ptr = (void *)
           xmalloc(8 + (ctx->big_endian ? token.length : plainlen)))) {
        if (sealalg != 0xffff)
        xfree_wrap(plain, tmsglen);
        if (toktype == KG_TOK_SEAL_MSG) {
        xfree_wrap(token.value, token.length);
        /* Solaris Kerberos: just to be safe since token.value is an
         * output parameter.
         */
        token.value = NULL;
        token.length = 0;
        }
        *minor_status = ENOMEM;
        return(GSS_S_FAILURE);
    }

    (void) memcpy(data_ptr, ptr-2, 8);

    if (ctx->big_endian) {
        KRB5_LOG0(KRB5_INFO, "kg_unseal_v1() ctx->big_endian = 1\n");
        (void) memcpy(data_ptr+8, token.value, token.length);
    }
    else {
        KRB5_LOG0(KRB5_INFO, "kg_unseal_v1() ctx->big_endian = 0\n");
        (void) memcpy(data_ptr+8, plain, plainlen);
    }

    plaind.length = 8 + (ctx->big_endian ? token.length : plainlen);
    plaind.data = data_ptr;

    code = krb5_c_make_checksum(context, md5cksum.checksum_type,
                    ctx->seq, sign_usage,
                    &plaind, &md5cksum);

    xfree_wrap(data_ptr, 8 + (ctx->big_endian ? token.length : plainlen));

    if (code) {
        if (toktype == KG_TOK_SEAL_MSG) {
        xfree_wrap(token.value, token.length);
        /* Solaris Kerberos: just to be safe since token.value is an
         * output parameter.
         */
        token.value = NULL;
        token.length = 0;
        }
        *minor_status = code;
        KRB5_LOG0(KRB5_ERR, "kg_unseal_v1() end, error "
            "SGN_ALG_HMAC_SHA1_DES3_KD GSS_S_FAILURE\n");
        return(GSS_S_FAILURE);
    }

    /* compare the computed checksum against the transmitted checksum */
    code = memcmp(md5cksum.contents, ptr+14, cksum_len);
    KRB5_LOG(KRB5_INFO, "kg_unseal_v1() memcmp %d bytes", cksum_len);
    break;
    }

    xfree_wrap(md5cksum.contents, md5cksum.length);
    if (sealalg != 0xffff)
    xfree_wrap(plain, tmsglen);

    if (code) {
    if (toktype == KG_TOK_SEAL_MSG) {
        xfree_wrap(token.value, token.length);
        /* Solaris Kerberos: just to be safe since token.value is an
         * output parameter.
         */
        token.value = NULL;
        token.length = 0;
    }
    *minor_status = 0;
    KRB5_LOG0(KRB5_ERR, "kg_unseal_v1() end, error GSS_S_BAD_SIG\n");
    return(GSS_S_BAD_SIG);
    }

    if (conf_state)
    *conf_state = (sealalg != 0xffff);

    if (qop_state)
    *qop_state = GSS_C_QOP_DEFAULT;

    if ((code = krb5_timeofday(context, &now))) {
    *minor_status = code;

    KRB5_LOG(KRB5_ERR, "kg_unseal_v1() end, krb5_timeofday()"
        "error code = %d\n", code);

    return(GSS_S_FAILURE);
    }

    if (now > ctx->endtime) {
    *minor_status = 0;

    KRB5_LOG1(KRB5_ERR, "kg_unseal_v1() end, error "
        "now %d > ctx->endtime %d\n", now, ctx->endtime);

    return(GSS_S_CONTEXT_EXPIRED);
    }

    /* do sequencing checks */
    if ((ctx->initiate && direction != 0xff) ||
    (!ctx->initiate && direction != 0)) {
    if (toktype == KG_TOK_SEAL_MSG) {
        xfree_wrap(token.value, token.length);
        /* Solaris Kerberos: just to be safe since token.value is an
         * output parameter.
         */
        token.value = NULL;
        token.length = 0;
    }
    *minor_status = (OM_uint32) G_BAD_DIRECTION;

    KRB5_LOG1(KRB5_ERR, "kg_unseal_v1() end, error GSS_S_BAD_SIG "
        "G_BAD_DIRECTION ctx->initiate = %d "
        "direction = %d\n", ctx->initiate, direction);

    return(GSS_S_BAD_SIG);
    }

    retval = g_order_check(&(ctx->seqstate), (gssint_uint64)seqnum);

    /* It got through unscathed, adjust the output message buffer. */
    if (retval == 0 && toktype == KG_TOK_SEAL_MSG)
    *message_buffer = token;

    *minor_status = 0;
    KRB5_LOG(KRB5_INFO, "kg_unseal_v1() end, retval = %d\n", retval);
    return(retval);
}

/* message_buffer is an input if SIGN, output if SEAL, and ignored if DEL_CTX
   conf_state is only valid if SEAL. */

OM_uint32
kg_unseal(context, minor_status, context_handle, input_token_buffer,
      message_buffer, conf_state, qop_state, toktype)
    krb5_context context;
    OM_uint32 *minor_status;
    gss_ctx_id_t context_handle;
    gss_buffer_t input_token_buffer;
    gss_buffer_t message_buffer;
    int *conf_state;
    int *qop_state;
    int toktype;
{
    krb5_gss_ctx_id_rec *ctx;
    unsigned char *ptr;
    int bodysize;
    int err;
    int toktype2;

    KRB5_LOG0(KRB5_INFO, "kg_unseal() start \n");

    /* validate the context handle */
    if (! kg_validate_ctx_id(context_handle)) {
    *minor_status = (OM_uint32) G_VALIDATE_FAILED;

    KRB5_LOG0(KRB5_ERR, "kg_unseal() end, kg_validate_ctx_id() error "
        "G_VALIDATE_FAILED \n");

    return(GSS_S_NO_CONTEXT);
    }

    ctx = (krb5_gss_ctx_id_rec *) context_handle;

    if (! ctx->established) {
    *minor_status = KG_CTX_INCOMPLETE;
    KRB5_LOG0(KRB5_ERR, "kg_unseal() end, error ! ctx->established \n");
    return(GSS_S_NO_CONTEXT);
    }

    /* parse the token, leave the data in message_buffer, setting conf_state */

    /* verify the header */
    ptr = (unsigned char *) input_token_buffer->value;
    if (ctx->proto)
    switch (toktype) {
    case KG_TOK_SIGN_MSG:
            toktype2 = 0x0404;
            break;
    case KG_TOK_SEAL_MSG:
            toktype2 = 0x0504;
            break;
    case KG_TOK_DEL_CTX:
            toktype2 = 0x0405;
            break;
    default:
            toktype2 = toktype;
            break;
    }
    else
        toktype2 = toktype;
    err = g_verify_token_header(&ctx->mech_used,
                (uint32_t *)&bodysize, &ptr, toktype2,
                input_token_buffer->length,
                !ctx->proto);
    if (err) {
    *minor_status = err;
    return GSS_S_DEFECTIVE_TOKEN;
    }


    if (ctx->proto == 0) {
    err = kg_unseal_v1(context, minor_status, ctx, ptr, bodysize,
                message_buffer, conf_state, qop_state,
                toktype);

    } else {
    err = gss_krb5int_unseal_token_v3(context, minor_status, ctx,
                                           ptr, bodysize, message_buffer,
                                           conf_state, qop_state, toktype);
    }

    *minor_status = err;

    KRB5_LOG(KRB5_INFO, "kg_unseal() end, err = %d", err);

    return(err);
}