path: root/source4/heimdal/kdc/pkinit.c

/*
 * Copyright (c) 2003 - 2005 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. 
 */

#include "kdc_locl.h"

RCSID("$Id: pkinit.c,v 1.59 2006/04/22 12:10:16 lha Exp $");

#ifdef PKINIT

#include <heim_asn1.h>
#include <rfc2459_asn1.h>
#include <cms_asn1.h>
#include <pkinit_asn1.h>

#include <hx509.h>
#include "crypto-headers.h"

/* XXX copied from lib/krb5/pkinit.c */
struct krb5_pk_identity {
    hx509_context hx509ctx;
    hx509_verify_ctx verify_ctx;
    hx509_certs certs;
    hx509_certs anchors;
    hx509_certs certpool;
    hx509_revoke_ctx revoke;
};

enum pkinit_type {
    PKINIT_COMPAT_WIN2K = 1,
    PKINIT_COMPAT_27 = 3
};

struct pk_client_params {
    enum pkinit_type type;
    BIGNUM *dh_public_key;
    hx509_cert cert;
    unsigned nonce;
    DH *dh;
    EncryptionKey reply_key;
    char *dh_group_name;
};

struct pk_principal_mapping {
    unsigned int len;
    struct pk_allowed_princ {
	krb5_principal principal;
	char *subject;
    } *val;
};

static struct krb5_pk_identity *kdc_identity;
static struct pk_principal_mapping principal_mappings;
static struct krb5_dh_moduli **moduli;

/*
 *
 */

static krb5_error_code
pk_check_pkauthenticator_win2k(krb5_context context,
			       PKAuthenticator_Win2k *a,
			       KDC_REQ *req)
{
    krb5_timestamp now;

    krb5_timeofday (context, &now);

    /* XXX cusec */
    if (a->ctime == 0 || abs(a->ctime - now) > context->max_skew) {
	krb5_clear_error_string(context);
	return KRB5KRB_AP_ERR_SKEW;
    }
    return 0;
}

static krb5_error_code
pk_check_pkauthenticator(krb5_context context,
			 PKAuthenticator *a,
			 KDC_REQ *req)
{
    u_char *buf = NULL;
    size_t buf_size;
    krb5_error_code ret;
    size_t len;
    krb5_timestamp now;
    Checksum checksum;

    krb5_timeofday (context, &now);

    /* XXX cusec */
    if (a->ctime == 0 || abs(a->ctime - now) > context->max_skew) {
	krb5_clear_error_string(context);
	return KRB5KRB_AP_ERR_SKEW;
    }

    ASN1_MALLOC_ENCODE(KDC_REQ_BODY, buf, buf_size, &req->req_body, &len, ret);
    if (ret) {
	krb5_clear_error_string(context);
	return ret;
    }
    if (buf_size != len)
	krb5_abortx(context, "Internal error in ASN.1 encoder");

    ret = krb5_create_checksum(context,
			       NULL,
			       0,
			       CKSUMTYPE_SHA1,
			       buf,
			       len,
			       &checksum);
    free(buf);
    if (ret) {
	krb5_clear_error_string(context);
	return ret;
    }
	
    if (a->paChecksum == NULL) {
	krb5_clear_error_string(context);
	ret = KRB5_KDC_ERR_PA_CHECKSUM_MUST_BE_INCLUDED;
	goto out;
    }

    if (heim_octet_string_cmp(a->paChecksum, &checksum.checksum) != 0) {
	krb5_clear_error_string(context);
	ret = KRB5KRB_ERR_GENERIC;
    }

out:
    free_Checksum(&checksum);

    return ret;
}

void
_kdc_pk_free_client_param(krb5_context context, 
			  pk_client_params *client_params)
{
    if (client_params->cert)
	hx509_cert_free(client_params->cert);
    if (client_params->dh)
	DH_free(client_params->dh);
    if (client_params->dh_public_key)
	BN_free(client_params->dh_public_key);
    krb5_free_keyblock_contents(context, &client_params->reply_key);
    if (client_params->dh_group_name)
	free(client_params->dh_group_name);
    memset(client_params, 0, sizeof(*client_params));
    free(client_params);
}

static krb5_error_code
generate_dh_keyblock(krb5_context context, pk_client_params *client_params,
                     krb5_enctype enctype, krb5_keyblock *reply_key)
{
    unsigned char *dh_gen_key = NULL;
    krb5_keyblock key;
    krb5_error_code ret;
    size_t dh_gen_keylen, size;

    memset(&key, 0, sizeof(key));

    if (!DH_generate_key(client_params->dh)) {
	krb5_set_error_string(context, "Can't generate Diffie-Hellman keys");
	ret = KRB5KRB_ERR_GENERIC;
	goto out;
    }
    if (client_params->dh_public_key == NULL) {
	krb5_set_error_string(context, "dh_public_key");
	ret = KRB5KRB_ERR_GENERIC;
	goto out;
    }

    dh_gen_keylen = DH_size(client_params->dh);
    size = BN_num_bytes(client_params->dh->p);
    if (size < dh_gen_keylen)
	size = dh_gen_keylen;

    dh_gen_key = malloc(size);
    if (dh_gen_key == NULL) {
	krb5_set_error_string(context, "malloc: out of memory");
	ret = ENOMEM;
	goto out;
    }
    memset(dh_gen_key, 0, size - dh_gen_keylen);

    dh_gen_keylen = DH_compute_key(dh_gen_key + (size - dh_gen_keylen),
				   client_params->dh_public_key,
				   client_params->dh);
    if (dh_gen_keylen == -1) {
	krb5_set_error_string(context, "Can't compute Diffie-Hellman key");
	ret = KRB5KRB_ERR_GENERIC;
	goto out;
    }

    ret = _krb5_pk_octetstring2key(context,
				   enctype,
				   dh_gen_key, dh_gen_keylen,
				   NULL, NULL,
				   reply_key);

 out:
    if (dh_gen_key)
	free(dh_gen_key);
    if (key.keyvalue.data)
	krb5_free_keyblock_contents(context, &key);

    return ret;
}

static BIGNUM *
integer_to_BN(krb5_context context, const char *field, heim_integer *f)
{
    BIGNUM *bn;

    bn = BN_bin2bn((const unsigned char *)f->data, f->length, NULL);
    if (bn == NULL) {
	krb5_set_error_string(context, "PKINIT: parsing BN failed %s", field);
	return NULL;
    }
    BN_set_negative(bn, f->negative);
    return bn;
}

static krb5_error_code
get_dh_param(krb5_context context,
	     krb5_kdc_configuration *config,
	     SubjectPublicKeyInfo *dh_key_info,
	     pk_client_params *client_params)
{
    DomainParameters dhparam;
    DH *dh = NULL;
    krb5_error_code ret;
    int dhret;

    memset(&dhparam, 0, sizeof(dhparam));

    if (heim_oid_cmp(&dh_key_info->algorithm.algorithm, oid_id_dhpublicnumber())) {
	krb5_set_error_string(context,
			      "PKINIT invalid oid in clientPublicValue");
	return KRB5_BADMSGTYPE;
    }

    if (dh_key_info->algorithm.parameters == NULL) {
	krb5_set_error_string(context, "PKINIT missing algorithm parameter "
			      "in clientPublicValue");
	return KRB5_BADMSGTYPE;
    }

    ret = decode_DomainParameters(dh_key_info->algorithm.parameters->data,
				  dh_key_info->algorithm.parameters->length,
				  &dhparam,
				  NULL);
    if (ret) {
	krb5_set_error_string(context, "Can't decode algorithm "
			      "parameters in clientPublicValue");
	goto out;
    }

    if ((dh_key_info->subjectPublicKey.length % 8) != 0) {
	ret = KRB5_BADMSGTYPE;
	krb5_set_error_string(context, "PKINIT: subjectPublicKey not aligned "
			      "to 8 bit boundary");
	goto out;
    }


    ret = _krb5_dh_group_ok(context, config->pkinit_dh_min_bits, 
			    &dhparam.p, &dhparam.g, &dhparam.q, moduli,
			    &client_params->dh_group_name);
    if (ret)
	goto out;

    dh = DH_new();
    if (dh == NULL) {
	krb5_set_error_string(context, "Cannot create DH structure");
	ret = ENOMEM;
	goto out;
    }
    ret = KRB5_BADMSGTYPE;
    dh->p = integer_to_BN(context, "DH prime", &dhparam.p);
    if (dh->p == NULL)
	goto out;
    dh->g = integer_to_BN(context, "DH base", &dhparam.g);
    if (dh->g == NULL)
	goto out;
    dh->q = integer_to_BN(context, "DH p-1 factor", &dhparam.q);
    if (dh->g == NULL)
	goto out;

    {
	heim_integer glue;
	size_t size;

	ret = decode_DHPublicKey(dh_key_info->subjectPublicKey.data,
				 dh_key_info->subjectPublicKey.length / 8,
				 &glue,
				 &size);
	if (ret) {
	    krb5_clear_error_string(context);
	    return ret;
	}

	client_params->dh_public_key = integer_to_BN(context,
						     "subjectPublicKey",
						     &glue);
	free_heim_integer(&glue);
	if (client_params->dh_public_key == NULL)
	    goto out;
    }


    if (DH_check_pubkey(dh, client_params->dh_public_key, &dhret) != 1 ||
	dhret != 0) {
	krb5_set_error_string(context, "PKINIT DH data not ok");
	ret = KRB5_KDC_ERR_DH_KEY_PARAMETERS_NOT_ACCEPTED;
	goto out;
    }

    client_params->dh = dh;
    dh = NULL;
    ret = 0;
    
 out:
    if (dh)
	DH_free(dh);
    free_DomainParameters(&dhparam);
    return ret;
}

#if 0
/* 
 * XXX We only need this function if there are several certs for the
 * KDC to choose from, and right now, we can't handle that so punt for
 * now.
 *
 * If client has sent a list of CA's trusted by him, make sure our
 * CA is in the list.
 *
 */

static void
verify_trusted_ca(PA_PK_AS_REQ_19 *r)
{

    if (r.trustedCertifiers != NULL) {
	X509_NAME *kdc_issuer;
	X509 *kdc_cert;

	kdc_cert = sk_X509_value(kdc_identity->cert, 0);
	kdc_issuer = X509_get_issuer_name(kdc_cert);
     
	/* XXX will work for heirarchical CA's ? */
	/* XXX also serial_number should be compared */

	ret = KRB5_KDC_ERR_KDC_NOT_TRUSTED;
	for (i = 0; i < r.trustedCertifiers->len; i++) {
	    TrustedCA_19 *ca = &r.trustedCertifiers->val[i];

	    switch (ca->element) {
	    case choice_TrustedCA_19_caName: {
		X509_NAME *name;
		unsigned char *p;

		p = ca->u.caName.data;
		name = d2i_X509_NAME(NULL, &p, ca->u.caName.length);
		if (name == NULL) /* XXX should this be a failure instead ? */
		    break;
		if (X509_NAME_cmp(name, kdc_issuer) == 0)
		    ret = 0;
		X509_NAME_free(name);
		break;
	    }
	    case choice_TrustedCA_19_issuerAndSerial:
		/* IssuerAndSerialNumber issuerAndSerial */
		break;
	    default:
		break;
	    }
	    if (ret == 0)
		break;
	}
	if (ret)
	    goto out;
    }
}
#endif /* 0 */

krb5_error_code
_kdc_pk_rd_padata(krb5_context context,
		  krb5_kdc_configuration *config,
		  KDC_REQ *req,
		  PA_DATA *pa,
		  pk_client_params **ret_params)
{
    pk_client_params *client_params;
    krb5_error_code ret;
    heim_oid eContentType = { 0, NULL }, contentInfoOid = { 0, NULL };
    krb5_data eContent = { 0, NULL };
    krb5_data signed_content = { 0, NULL };
    const char *type = "unknown type";
    const heim_oid *pa_contentType;
    int have_data;

    *ret_params = NULL;
    
    if (!config->enable_pkinit) {
	krb5_clear_error_string(context);
	return 0;
    }

    client_params = calloc(1, sizeof(*client_params));
    if (client_params == NULL) {
	krb5_clear_error_string(context);
	ret = ENOMEM;
	goto out;
    }

    if (pa->padata_type == KRB5_PADATA_PK_AS_REQ_WIN) {
	PA_PK_AS_REQ_Win2k r;
	int have_data;

	type = "PK-INIT-Win2k";
	pa_contentType = oid_id_pkcs7_data();

	ret = decode_PA_PK_AS_REQ_Win2k(pa->padata_value.data,
					pa->padata_value.length,
					&r,
					NULL);
	if (ret) {
	    krb5_set_error_string(context, "Can't decode "
				  "PK-AS-REQ-Win2k: %d", ret);
	    goto out;
	}
	
	ret = hx509_cms_unwrap_ContentInfo(&r.signed_auth_pack,
					   &contentInfoOid,
					   &signed_content,
					   &have_data);
	free_PA_PK_AS_REQ_Win2k(&r);
	if (ret) {
	    krb5_set_error_string(context, "Can't decode PK-AS-REQ: %d", ret);
	    goto out;
	}

    } else if (pa->padata_type == KRB5_PADATA_PK_AS_REQ) {
	PA_PK_AS_REQ r;

	type = "PK-INIT-IETF";
	pa_contentType = oid_id_pkauthdata();

	ret = decode_PA_PK_AS_REQ(pa->padata_value.data,
				  pa->padata_value.length,
				  &r,
				  NULL);
	if (ret) {
	    krb5_set_error_string(context, "Can't decode PK-AS-REQ: %d", ret);
	    goto out;
	}
	
	/* XXX look at r.trustedCertifiers and r.kdcPkId */

	ret = hx509_cms_unwrap_ContentInfo(&r.signedAuthPack,
					   &contentInfoOid,
					   &signed_content,
					   &have_data);
	free_PA_PK_AS_REQ(&r);
	if (ret) {
	    krb5_set_error_string(context, "Can't unwrap ContentInfo: %d", ret);
	    goto out;
	}

    } else { 
	krb5_clear_error_string(context);
	ret = KRB5KDC_ERR_PADATA_TYPE_NOSUPP;
	goto out;
    }

    ret = heim_oid_cmp(&contentInfoOid, oid_id_pkcs7_signedData());
    if (ret != 0) {
	krb5_set_error_string(context, "PK-AS-REQ-Win2k invalid content "
			      "type oid");
	ret = KRB5KRB_ERR_GENERIC;
	goto out;
    }
	
    if (!have_data) {
	krb5_set_error_string(context,
			      "PK-AS-REQ-Win2k no signed auth pack");
	ret = KRB5KRB_ERR_GENERIC;
	goto out;
    }

    {
	hx509_certs signer_certs;

	ret = hx509_cms_verify_signed(kdc_identity->hx509ctx,
				      kdc_identity->verify_ctx,
				      signed_content.data,
				      signed_content.length,
				      kdc_identity->certpool,
				      &eContentType,
				      &eContent,
				      &signer_certs);
	if (ret) {
	    kdc_log(context, config, 0,
		    "PK-INIT failed to verify signature %d", ret);
	    goto out;
	}

	ret = hx509_get_one_cert(kdc_identity->hx509ctx, signer_certs,
				 &client_params->cert);
	hx509_certs_free(&signer_certs);
	if (ret)
	    goto out;
    }

    /* Signature is correct, now verify the signed message */
    if (heim_oid_cmp(&eContentType, pa_contentType)) {
	krb5_set_error_string(context, "got wrong oid for pkauthdata");
	ret = KRB5_BADMSGTYPE;
	goto out;
    }

    if (pa->padata_type == KRB5_PADATA_PK_AS_REQ_WIN) {
	AuthPack_Win2k ap;

	ret = decode_AuthPack_Win2k(eContent.data,
				    eContent.length,
				    &ap,
				    NULL);
	if (ret) {
	    krb5_set_error_string(context, "can't decode AuthPack: %d", ret);
	    goto out;
	}
  
	ret = pk_check_pkauthenticator_win2k(context, 
					     &ap.pkAuthenticator,
					     req);
	if (ret) {
	    free_AuthPack_Win2k(&ap);
	    goto out;
	}

	client_params->type = PKINIT_COMPAT_WIN2K;
	client_params->nonce = ap.pkAuthenticator.nonce;

	if (ap.clientPublicValue) {
	    krb5_set_error_string(context, "DH not supported for windows");
	    ret = KRB5KRB_ERR_GENERIC;
	    goto out;
	}
	free_AuthPack_Win2k(&ap);

    } else if (pa->padata_type == KRB5_PADATA_PK_AS_REQ) {
	AuthPack ap;

	ret = decode_AuthPack(eContent.data,
			      eContent.length,
			      &ap,
			      NULL);
	if (ret) {
	    krb5_set_error_string(context, "can't decode AuthPack: %d", ret);
	    free_AuthPack(&ap);
	    goto out;
	}
  
	ret = pk_check_pkauthenticator(context, 
				       &ap.pkAuthenticator,
				       req);
	if (ret) {
	    free_AuthPack(&ap);
	    goto out;
	}

	client_params->type = PKINIT_COMPAT_27;
	client_params->nonce = ap.pkAuthenticator.nonce;

	if (ap.clientPublicValue) {
	    ret = get_dh_param(context, config, 
			       ap.clientPublicValue, client_params);
	    if (ret) {
		free_AuthPack(&ap);
		goto out;
	    }
	}
	free_AuthPack(&ap);
    } else
	krb5_abortx(context, "internal pkinit error");

    kdc_log(context, config, 0, "PK-INIT request of type %s", type);

out:

    if (signed_content.data)
	free(signed_content.data);
    krb5_data_free(&eContent);
    free_oid(&eContentType);
    free_oid(&contentInfoOid);
    if (ret)
	_kdc_pk_free_client_param(context, client_params);
    else
	*ret_params = client_params;
    return ret;
}

/*
 *
 */

static krb5_error_code
BN_to_integer(krb5_context context, BIGNUM *bn, heim_integer *integer)
{
    integer->length = BN_num_bytes(bn);
    integer->data = malloc(integer->length);
    if (integer->data == NULL) {
	krb5_clear_error_string(context);
	return ENOMEM;
    }
    BN_bn2bin(bn, integer->data);
    integer->negative = BN_is_negative(bn);
    return 0;
}

static krb5_error_code
pk_mk_pa_reply_enckey(krb5_context context,
		      pk_client_params *client_params,
		      const KDC_REQ *req,
		      const krb5_data *req_buffer,
		      krb5_keyblock *reply_key,
		      ContentInfo *content_info)
{
    krb5_error_code ret;
    krb5_data buf, o;
    size_t size;

    krb5_data_zero(&buf);

    switch (client_params->type) {
    case PKINIT_COMPAT_WIN2K: {
	ReplyKeyPack_Win2k kp;
	memset(&kp, 0, sizeof(kp));

	ret = copy_EncryptionKey(reply_key, &kp.replyKey);
	if (ret) {
	    krb5_clear_error_string(context);
	    goto out;
	}
	kp.nonce = client_params->nonce;
	
	ASN1_MALLOC_ENCODE(ReplyKeyPack_Win2k, 
			   buf.data, buf.length,
			   &kp, &size,ret);
	free_ReplyKeyPack_Win2k(&kp);
    }
    case PKINIT_COMPAT_27: {
	krb5_crypto ascrypto;
	ReplyKeyPack kp;
	memset(&kp, 0, sizeof(kp));

	ret = copy_EncryptionKey(reply_key, &kp.replyKey);
	if (ret) {
	    krb5_clear_error_string(context);
	    goto out;
	}

	ret = krb5_crypto_init(context, reply_key, 0, &ascrypto);
	if (ret) {
	    krb5_clear_error_string(context);
	    goto out;
	}

	ret = krb5_create_checksum(context, ascrypto, 6, 0,
				   req_buffer->data, req_buffer->length,
				   &kp.asChecksum);
	if (ret) {
	    krb5_clear_error_string(context);
	    goto out;
	}
			     
	ret = krb5_crypto_destroy(context, ascrypto);
	if (ret) {
	    krb5_clear_error_string(context);
	    goto out;
	}
	ASN1_MALLOC_ENCODE(ReplyKeyPack, buf.data, buf.length, &kp, &size,ret);
	free_ReplyKeyPack(&kp);
	break;
    }
    default:
	krb5_abortx(context, "internal pkinit error");
    }
    if (ret) {
	krb5_set_error_string(context, "ASN.1 encoding of ReplyKeyPack "
			      "failed (%d)", ret);
	goto out;
    }
    if (buf.length != size)
	krb5_abortx(context, "Internal ASN.1 encoder error");

    ret = hx509_cms_envelope_1(kdc_identity->hx509ctx,
			       client_params->cert,
			       buf.data, buf.length, NULL,
			       oid_id_pkcs7_signedData(), &o);
    if (ret)
	goto out;
    
    ret = _krb5_pk_mk_ContentInfo(context,
				  &o,
				  oid_id_pkcs7_envelopedData(),
				  content_info);
    free_octet_string(&o);

 out:
    krb5_data_free(&buf);
    return ret;
}

/*
 *
 */

static krb5_error_code
pk_mk_pa_reply_dh(krb5_context context,
                  DH *kdc_dh,
      		  pk_client_params *client_params,
                  krb5_keyblock *reply_key,
		  ContentInfo *content_info)
{
    KDCDHKeyInfo dh_info;
    krb5_data signed_data, buf;
    ContentInfo contentinfo;
    krb5_error_code ret;
    size_t size;
    heim_integer i;

    memset(&contentinfo, 0, sizeof(contentinfo));
    memset(&dh_info, 0, sizeof(dh_info));
    krb5_data_zero(&buf);
    krb5_data_zero(&signed_data);

    ret = BN_to_integer(context, kdc_dh->pub_key, &i);
    if (ret)
	return ret;

    ASN1_MALLOC_ENCODE(DHPublicKey, buf.data, buf.length, &i, &size, ret);
    if (ret) {
	krb5_set_error_string(context, "ASN.1 encoding of "
			      "DHPublicKey failed (%d)", ret);
	krb5_clear_error_string(context);
	return ret;
    }
    if (buf.length != size)
	krb5_abortx(context, "Internal ASN.1 encoder error");

    dh_info.subjectPublicKey.length = buf.length * 8;
    dh_info.subjectPublicKey.data = buf.data;
    
    dh_info.nonce = client_params->nonce;

    ASN1_MALLOC_ENCODE(KDCDHKeyInfo, buf.data, buf.length, &dh_info, &size, 
		       ret);
    if (ret) {
	krb5_set_error_string(context, "ASN.1 encoding of "
			      "KdcDHKeyInfo failed (%d)", ret);
	goto out;
    }
    if (buf.length != size)
	krb5_abortx(context, "Internal ASN.1 encoder error");

    /* 
     * Create the SignedData structure and sign the KdcDHKeyInfo
     * filled in above
     */

    {
	hx509_cert cert;
	hx509_query *q;
	
	ret = hx509_query_alloc(kdc_identity->hx509ctx, &q);
	if (ret)
	    goto out;
	
	hx509_query_match_option(q, HX509_QUERY_OPTION_PRIVATE_KEY);
	hx509_query_match_option(q, HX509_QUERY_OPTION_KU_DIGITALSIGNATURE);
	
	ret = hx509_certs_find(kdc_identity->hx509ctx, 
			       kdc_identity->certs, 
			       q, 
			       &cert);
	hx509_query_free(kdc_identity->hx509ctx, q);
	if (ret)
	    goto out;
	
	ret = hx509_cms_create_signed_1(kdc_identity->hx509ctx,
					oid_id_pkdhkeydata(),
					buf.data,
					buf.length,
					NULL,
					cert,
					kdc_identity->anchors,
					kdc_identity->certpool,
					&signed_data);
	hx509_cert_free(cert);
    }
    if (ret)
	goto out;

    ret = _krb5_pk_mk_ContentInfo(context,
				  &signed_data,
				  oid_id_pkcs7_signedData(),
				  content_info);
    if (ret)
	goto out;

 out:
    krb5_data_free(&buf);
    krb5_data_free(&signed_data);
    free_KDCDHKeyInfo(&dh_info);

    return ret;
}

/*
 *
 */

krb5_error_code
_kdc_pk_mk_pa_reply(krb5_context context,
		    krb5_kdc_configuration *config,
		    pk_client_params *client_params,
		    const hdb_entry_ex *client,
		    const KDC_REQ *req,
		    const krb5_data *req_buffer,
		    krb5_keyblock **reply_key,
		    METHOD_DATA *md)
{
    krb5_error_code ret;
    void *buf;
    size_t len, size;
    krb5_enctype enctype;
    int pa_type;
    int i;

    if (!config->enable_pkinit) {
	krb5_clear_error_string(context);
	return 0;
    }

    if (req->req_body.etype.len > 0) {
	for (i = 0; i < req->req_body.etype.len; i++)
	    if (krb5_enctype_valid(context, req->req_body.etype.val[i]) == 0)
		break;
	if (req->req_body.etype.len <= i) {
	    ret = KRB5KRB_ERR_GENERIC;
	    krb5_set_error_string(context,
				  "No valid enctype available from client");
	    goto out;
	}	
	enctype = req->req_body.etype.val[i];
    } else
	enctype = ETYPE_DES3_CBC_SHA1;

    if (client_params->type == PKINIT_COMPAT_27) {
	PA_PK_AS_REP rep;
	const char *type, *other = "";

	memset(&rep, 0, sizeof(rep));

	pa_type = KRB5_PADATA_PK_AS_REP;

	if (client_params->dh == NULL) {
	    ContentInfo info;

	    type = "enckey";

	    rep.element = choice_PA_PK_AS_REP_encKeyPack;

	    krb5_generate_random_keyblock(context, enctype, 
					  &client_params->reply_key);
	    ret = pk_mk_pa_reply_enckey(context,
					client_params,
					req,
					req_buffer,
					&client_params->reply_key,
					&info);
	    if (ret) {
		free_PA_PK_AS_REP(&rep);
		goto out;
	    }
	    ASN1_MALLOC_ENCODE(ContentInfo, rep.u.encKeyPack.data, 
			       rep.u.encKeyPack.length, &info, &size, 
			       ret);
	    free_ContentInfo(&info);
	    if (ret) {
		krb5_set_error_string(context, "encoding of Key ContentInfo "
				      "failed %d", ret);
		free_PA_PK_AS_REP(&rep);
		goto out;
	    }
	    if (rep.u.encKeyPack.length != size)
		krb5_abortx(context, "Internal ASN.1 encoder error");

	} else {
	    ContentInfo info;

	    type = "dh";
	    if (client_params->dh_group_name)
		other = client_params->dh_group_name;

	    rep.element = choice_PA_PK_AS_REP_dhInfo;

	    ret = generate_dh_keyblock(context, client_params, enctype,
				       &client_params->reply_key);
	    if (ret)
		return ret;

	    ret = pk_mk_pa_reply_dh(context, client_params->dh,
				    client_params, 
				    &client_params->reply_key,
				    &info);

	    ASN1_MALLOC_ENCODE(ContentInfo, rep.u.dhInfo.dhSignedData.data,
			       rep.u.dhInfo.dhSignedData.length, &info, &size,
			       ret);
	    free_ContentInfo(&info);
	    if (ret) {
		krb5_set_error_string(context, "encoding of Key ContentInfo "
				      "failed %d", ret);
		free_PA_PK_AS_REP(&rep);
		goto out;
	    }
	    if (rep.u.encKeyPack.length != size)
		krb5_abortx(context, "Internal ASN.1 encoder error");

	}
	if (ret) {
	    free_PA_PK_AS_REP(&rep);
	    goto out;
	}

	ASN1_MALLOC_ENCODE(PA_PK_AS_REP, buf, len, &rep, &size, ret);
	free_PA_PK_AS_REP(&rep);
	if (ret) {
	    krb5_set_error_string(context, "encode PA-PK-AS-REP failed %d",
				  ret);
	    goto out;
	}
	if (len != size)
	    krb5_abortx(context, "Internal ASN.1 encoder error");

	kdc_log(context, config, 0, "PK-INIT using %s %s", type, other);

    } else if (client_params->type == PKINIT_COMPAT_WIN2K) {
	PA_PK_AS_REP_Win2k rep;

	pa_type = KRB5_PADATA_PK_AS_REP_19;

	memset(&rep, 0, sizeof(rep));

	if (client_params->dh) {
	    krb5_set_error_string(context, "DH -27 not implemented");
	    ret = KRB5KRB_ERR_GENERIC;
	} else {
	    rep.element = choice_PA_PK_AS_REP_encKeyPack;
	    ContentInfo info;

	    krb5_generate_random_keyblock(context, enctype, 
					  &client_params->reply_key);
	    ret = pk_mk_pa_reply_enckey(context,
					client_params,
					req,
					req_buffer,
					&client_params->reply_key,
					&info);
	    if (ret) {
		free_PA_PK_AS_REP_Win2k(&rep);
		goto out;
	    }
	    ASN1_MALLOC_ENCODE(ContentInfo, rep.u.encKeyPack.data, 
			       rep.u.encKeyPack.length, &info, &size, 
			       ret);
	    free_ContentInfo(&info);
	    if (ret) {
		krb5_set_error_string(context, "encoding of Key ContentInfo "
				      "failed %d", ret);
		free_PA_PK_AS_REP_Win2k(&rep);
		goto out;
	    }
	    if (rep.u.encKeyPack.length != size)
		krb5_abortx(context, "Internal ASN.1 encoder error");

	}
	if (ret) {
	    free_PA_PK_AS_REP_Win2k(&rep);
	    goto out;
	}

	ASN1_MALLOC_ENCODE(PA_PK_AS_REP_Win2k, buf, len, &rep, &size, ret);
	free_PA_PK_AS_REP_Win2k(&rep);
	if (ret) {
	    krb5_set_error_string(context, 
				  "encode PA-PK-AS-REP-Win2k failed %d", ret);
	    goto out;
	}
	if (len != size)
	    krb5_abortx(context, "Internal ASN.1 encoder error");

    } else
	krb5_abortx(context, "PK-INIT internal error");


    ret = krb5_padata_add(context, md, pa_type, buf, len);
    if (ret) {
	krb5_set_error_string(context, "failed adding "
			      "PA-PK-AS-REP-19 %d", ret);
	free(buf);
    }
 out:
    if (ret == 0)
	*reply_key = &client_params->reply_key;
    return ret;
}

static int
pk_principal_from_X509(krb5_context context, 
		       krb5_kdc_configuration *config,
		       hx509_cert client_cert, 
		       krb5_const_principal match)
{
    hx509_octet_string_list list;
    int ret, i, found = 0;

    memset(&list, 0 , sizeof(list));

    ret = hx509_cert_find_subjectAltName_otherName(client_cert,
						   oid_id_pkinit_san(),
						   &list);
    if (ret)
	goto out;

    for (i = 0; !found && i < list.len; i++) {
	krb5_principal_data principal;
	KRB5PrincipalName kn;
	size_t size;

	ret = decode_KRB5PrincipalName(list.val[i].data, 
				       list.val[i].length,
				       &kn, &size);
	if (ret) {
	    kdc_log(context, config, 0,
		    "Decoding kerberos name in certificate failed: %s",
		    krb5_get_err_text(context, ret));
	    break;
	}
	if (size != list.val[i].length) {
	    kdc_log(context, config, 0,
		    "Decoding kerberos name have extra bits on the end");
	    return KRB5_KDC_ERR_CLIENT_NAME_MISMATCH;
	}

	principal.name = kn.principalName;
	principal.realm = kn.realm;

	if (krb5_principal_compare(context, &principal, match) == TRUE)
	    found = 1;
	free_KRB5PrincipalName(&kn);
    }

out:
    hx509_free_octet_string_list(&list);    
    if (ret)
	return ret;

    if (!found)
	return KRB5_KDC_ERR_CLIENT_NAME_MISMATCH;

    return 0;
}


krb5_error_code
_kdc_pk_check_client(krb5_context context,
		     krb5_kdc_configuration *config,
		     krb5_principal client_princ,
		     const hdb_entry_ex *client,
		     pk_client_params *client_params,
		     char **subject_name)
{
    krb5_error_code ret;
    hx509_name name;
    int i;

    if (config->enable_pkinit_princ_in_cert) {
	ret = pk_principal_from_X509(context, config, 
				     client_params->cert,
				     client_princ);
	if (ret == 0)
	    return 0;
    }

    ret = hx509_cert_get_subject(client_params->cert, &name);
    if (ret)
	return ret;

    ret = hx509_name_to_string(name, subject_name);
    hx509_name_free(&name);
    if (ret)
	return ret;

    kdc_log(context, config, 5,
	    "Trying to authorize subject DN %s", 
	    *subject_name);

    for (i = 0; i < principal_mappings.len; i++) {
	krb5_boolean b;

	b = krb5_principal_compare(context,
				   client_princ,
				   principal_mappings.val[i].principal);
	if (b == FALSE)
	    continue;
	if (strcmp(principal_mappings.val[i].subject, *subject_name) != 0)
	    continue;
	return 0;
    }
    free(*subject_name);

    *subject_name = NULL;
    krb5_set_error_string(context, "PKINIT no matching principals");
    return KRB5_KDC_ERR_CLIENT_NAME_MISMATCH;
}

static krb5_error_code
add_principal_mapping(krb5_context context, 
		      const char *principal_name,
		      const char * subject)
{
   struct pk_allowed_princ *tmp;
   krb5_principal principal;
   krb5_error_code ret;

   tmp = realloc(principal_mappings.val,
	         (principal_mappings.len + 1) * sizeof(*tmp));
   if (tmp == NULL)
       return ENOMEM;
   principal_mappings.val = tmp;

   ret = krb5_parse_name(context, principal_name, &principal);
   if (ret)
       return ret;

   principal_mappings.val[principal_mappings.len].principal = principal;

   principal_mappings.val[principal_mappings.len].subject = strdup(subject);
   if (principal_mappings.val[principal_mappings.len].subject == NULL) {
       krb5_free_principal(context, principal);
       return ENOMEM;
   }
   principal_mappings.len++;

   return 0;
}


krb5_error_code
_kdc_pk_initialize(krb5_context context,
		   krb5_kdc_configuration *config,
		   const char *user_id,
		   const char *anchors,
		   char **pool,
		   char **revoke)
{
    const char *file; 
    krb5_error_code ret;
    char buf[1024];
    unsigned long lineno = 0;
    FILE *f;

    file = krb5_config_get_string(context, NULL,
				  "libdefaults", "moduli", NULL);

    ret = _krb5_parse_moduli(context, file, &moduli);
    if (ret)
	krb5_err(context, 1, ret, "PKINIT: failed to load modidi file");

    principal_mappings.len = 0;
    principal_mappings.val = NULL;

    ret = _krb5_pk_load_id(context,
			   &kdc_identity,
			   user_id,
			   anchors,
			   pool,
			   revoke,
			   NULL,
			   NULL,
			   NULL);
    if (ret) {
	krb5_warn(context, ret, "PKINIT: failed to load");
	config->enable_pkinit = 0;
	return ret;
    }

    file = krb5_config_get_string_default(context, 
					  NULL,
					  HDB_DB_DIR "/pki-mapping",
					  "kdc",
					  "pki-mappings-file",
					  NULL);
    f = fopen(file, "r");
    if (f == NULL) {
	krb5_warnx(context, "PKINIT: failed to load mappings file %s", file);
	return 0;
    }

    while (fgets(buf, sizeof(buf), f) != NULL) {
	char *subject_name, *p;
    
	buf[strcspn(buf, "\n")] = '\0';
	lineno++;

	p = buf + strspn(buf, " \t");

	if (*p == '#' || *p == '\0')
	    continue;

	subject_name = strchr(p, ':');
	if (subject_name == NULL) {
	    krb5_warnx(context, "pkinit mapping file line %lu "
		       "missing \":\" :%s",
		       lineno, buf);
	    continue;
	}
	*subject_name++ = '\0';

	ret = add_principal_mapping(context, p, subject_name);
	if (ret) {
	    krb5_warn(context, ret, "failed to add line %lu \":\" :%s\n",
		      lineno, buf);
	    continue;
	}
    } 

    fclose(f);

    return 0;
}

#endif /* PKINIT */