xref: /macosx-10.10/Heimdal-398.1.2/lib/hx509/cert.c

/*
 * Copyright (c) 2004 - 2007 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Portions Copyright (c) 2009 - 2010 Apple Inc. 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 "hx_locl.h"
#include "crypto-headers.h"
#include <rtbl.h>

/**
 * @page page_cert The basic certificate
 *
 * The basic hx509 cerificate object in hx509 is hx509_cert. The
 * hx509_cert object is representing one X509/PKIX certificate and
 * associated attributes; like private key, friendly name, etc.
 *
 * A hx509_cert object is usully found via the keyset interfaces (@ref
 * page_keyset), but its also possible to create a certificate
 * directly from a parsed object with hx509_cert_init() and
 * hx509_cert_init_data().
 *
 * See the library functions here: @ref hx509_cert
 */

struct hx509_verify_ctx_data {
    hx509_certs trust_anchors;
    int flags;
#define HX509_VERIFY_CTX_F_TIME_SET			1
#define HX509_VERIFY_CTX_F_ALLOW_PROXY_CERTIFICATE	2
#define HX509_VERIFY_CTX_F_REQUIRE_RFC3280		4
#define HX509_VERIFY_CTX_F_CHECK_TRUST_ANCHORS		8
#define HX509_VERIFY_CTX_F_NO_DEFAULT_ANCHORS		16
#define HX509_VERIFY_CTX_F_NO_BEST_BEFORE_CHECK		32
    time_t time_now;
    unsigned int max_depth;
#define HX509_VERIFY_MAX_DEPTH 30
    hx509_revoke_ctx revoke_ctx;
};

#define REQUIRE_RFC3280(ctx) ((ctx)->flags & HX509_VERIFY_CTX_F_REQUIRE_RFC3280)
#define CHECK_TA(ctx) ((ctx)->flags & HX509_VERIFY_CTX_F_CHECK_TRUST_ANCHORS)
#define ALLOW_DEF_TA(ctx) (((ctx)->flags & HX509_VERIFY_CTX_F_NO_DEFAULT_ANCHORS) == 0)

struct _hx509_cert_attrs {
    size_t len;
    hx509_cert_attribute *val;
};

struct hx509_cert_data {
    struct heim_base_uniq base;
    char *friendlyname;
    heim_octet_string persistent;
    Certificate *data;
    hx509_private_key private_key;
    struct _hx509_cert_attrs attrs;
    hx509_name basename;
    _hx509_cert_release_func release;
    void *ctx;
};

typedef struct hx509_name_constraints {
    NameConstraints *val;
    size_t len;
} hx509_name_constraints;

/*
 *
 */

#define GeneralSubtrees_SET(g,var) \
	(g)->len = (var)->len, (g)->val = (var)->val;

/**
 * Creates a hx509 context that most functions in the library
 * uses. The context is only allowed to be used by one thread at each
 * moment. Free the context with hx509_context_free().
 *
 * @param context Returns a pointer to new hx509 context.
 *
 * @return Returns an hx509 error code.
 *
 * @ingroup hx509
 */

int
hx509_context_init(hx509_context *context)
{
    *context = calloc(1, sizeof(**context));
    if (*context == NULL)
	return ENOMEM;

    _hx509_ks_null_register(*context);
    _hx509_ks_mem_register(*context);
    _hx509_ks_file_register(*context);
    _hx509_ks_pkcs12_register(*context);
    _hx509_ks_pkcs11_register(*context);
    _hx509_ks_dir_register(*context);
    _hx509_ks_keychain_register(*context);

    ENGINE_add_conf_module();
    OpenSSL_add_all_algorithms();

    (*context)->ocsp_time_diff = HX509_DEFAULT_OCSP_TIME_DIFF;

    initialize_hx_error_table_r(&(*context)->et_list);
    initialize_asn1_error_table_r(&(*context)->et_list);

#ifdef HX509_DEFAULT_ANCHORS
    (void)hx509_certs_init(*context, HX509_DEFAULT_ANCHORS, 0,
			   NULL, &(*context)->default_trust_anchors);
#endif

    return 0;
}

/**
 * Selects if the hx509_revoke_verify() function is going to require
 * the existans of a revokation method (OCSP, CRL) or not. Note that
 * hx509_verify_path(), hx509_cms_verify_signed(), and other function
 * call hx509_revoke_verify().
 *
 * @param context hx509 context to change the flag for.
 * @param flag zero, revokation method required, non zero missing
 * revokation method ok
 *
 * @ingroup hx509_verify
 */

void
hx509_context_set_missing_revoke(hx509_context context, int flag)
{
    if (flag)
	context->flags |= HX509_CTX_VERIFY_MISSING_OK;
    else
	context->flags &= ~HX509_CTX_VERIFY_MISSING_OK;
}

/**
 * Free the context allocated by hx509_context_init().
 *
 * @param context context to be freed.
 *
 * @ingroup hx509
 */

void
hx509_context_free(hx509_context *context)
{
    hx509_certs_free(&(*context)->default_trust_anchors);
    hx509_clear_error_string(*context);
    if ((*context)->ks_ops) {
	free((*context)->ks_ops);
	(*context)->ks_ops = NULL;
    }
    (*context)->ks_num_ops = 0;
    free_error_table ((*context)->et_list);
    memset(*context, 0, sizeof(**context));
    free(*context);
    *context = NULL;
}

/*
 *
 */

Certificate *
_hx509_get_cert(hx509_cert cert)
{
    return cert->data;
}

/*
 *
 */

int
_hx509_cert_get_version(const Certificate *t)
{
    return t->tbsCertificate.version ? *t->tbsCertificate.version + 1 : 1;
}

/*
 *
 */

static void
cert_free(heim_object_t object)
{
    hx509_cert cert = object;
    size_t i;

    if (cert->release)
	(cert->release)(cert, cert->ctx);

    if (cert->private_key)
	hx509_private_key_free(&cert->private_key);

    if (cert->data) {
	free_Certificate(cert->data);
	free(cert->data);
    }

    for (i = 0; i < cert->attrs.len; i++) {
	der_free_octet_string(&cert->attrs.val[i]->data);
	der_free_oid(&cert->attrs.val[i]->oid);
	free(cert->attrs.val[i]);
    }
    free(cert->attrs.val);
    free(cert->friendlyname);
    if (cert->basename)
	hx509_name_free(&cert->basename);
    der_free_octet_string(&cert->persistent);
}


/**
 * Allocate and init an hx509 certificate object from the decoded
 * certificate `c´.
 *
 * @param context A hx509 context.
 * @param c certificate to parse
 * @param cert return certificate, free with heim_release()
 *
 * @return Returns an hx509 error code.
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_init(hx509_context context, const Certificate *c, hx509_cert *cert)
{
    int ret;

    *cert = heim_uniq_alloc(sizeof(**cert), "hx509-cert", cert_free);
    if (*cert == NULL)
	return ENOMEM;
    (*cert)->friendlyname = NULL;
    (*cert)->attrs.len = 0;
    (*cert)->attrs.val = NULL;
    (*cert)->private_key = NULL;
    (*cert)->basename = NULL;
    (*cert)->release = NULL;
    (*cert)->ctx = NULL;

    (*cert)->data = calloc(1, sizeof(*(*cert)->data));
    if ((*cert)->data == NULL) {
	heim_release(*cert);
	*cert = NULL;
	return ENOMEM;
    }
    ret = copy_Certificate(c, (*cert)->data);
    if (ret) {
	heim_release(*cert);
	*cert = NULL;
    }
    return ret;
}

/**
 * Just like hx509_cert_init(), but instead of a decode certificate
 * takes an pointer and length to a memory region that contains a
 * DER/BER encoded certificate.
 *
 * If the memory region doesn't contain just the certificate and
 * nothing more the function will fail with
 * HX509_EXTRA_DATA_AFTER_STRUCTURE.
 *
 * @param context A hx509 context.
 * @param ptr pointer to memory region containing encoded certificate.
 * @param len length of memory region.
 * @param cert a return pointer to a hx509 certificate object, will
 * contain NULL on error.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_init_data(hx509_context context,
		     const void *ptr,
		     size_t len,
		     hx509_cert *cert)
{
    Certificate t;
    size_t size;
    int ret;

    ret = decode_Certificate(ptr, len, &t, &size);
    if (ret) {
	hx509_set_error_string(context, 0, ret, "Failed to decode certificate");
	return ret;
    }
    if (size != len) {
	free_Certificate(&t);
	hx509_set_error_string(context, 0, HX509_EXTRA_DATA_AFTER_STRUCTURE,
			       "Extra data after certificate");
	return HX509_EXTRA_DATA_AFTER_STRUCTURE;
    }

    ret = hx509_cert_init(context, &t, cert);
    free_Certificate(&t);
    return ret;
}

void
_hx509_cert_set_release(hx509_cert cert,
			_hx509_cert_release_func release,
			void *ctx)
{
    cert->release = release;
    cert->ctx = ctx;
}


/* Doesn't make a copy of `private_key'. */

int
_hx509_cert_set_key(hx509_cert cert, hx509_private_key private_key)
{
    if (cert->private_key)
	hx509_private_key_free(&cert->private_key);
    cert->private_key = _hx509_private_key_ref(private_key);
    return 0;
}

/**
 * Free reference to the hx509 certificate object, if the refcounter
 * reaches 0, the object if freed. Its allowed to pass in NULL.
 *
 * @param cert the cert to free.
 *
 * @ingroup hx509_cert
 */

void
hx509_cert_free(hx509_cert cert)
{
    heim_release(cert);
}

/**
 * Add a reference to a hx509 certificate object.
 *
 * @param cert a pointer to an hx509 certificate object.
 *
 * @return the same object as is passed in.
 *
 * @ingroup hx509_cert
 */

hx509_cert
hx509_cert_ref(hx509_cert cert)
{
    return heim_retain(cert);
}

/**
 * Allocate an verification context that is used fo control the
 * verification process.
 *
 * @param context A hx509 context.
 * @param ctx returns a pointer to a hx509_verify_ctx object.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_verify
 */

int
hx509_verify_init_ctx(hx509_context context, hx509_verify_ctx *ctx)
{
    hx509_verify_ctx c;

    c = calloc(1, sizeof(*c));
    if (c == NULL)
	return ENOMEM;

    c->max_depth = HX509_VERIFY_MAX_DEPTH;

    *ctx = c;

    return 0;
}

/**
 * Free an hx509 verification context.
 *
 * @param ctx the context to be freed.
 *
 * @ingroup hx509_verify
 */

void
hx509_verify_destroy_ctx(hx509_verify_ctx ctx)
{
    if (ctx) {
	hx509_certs_free(&ctx->trust_anchors);
	hx509_revoke_free(&ctx->revoke_ctx);
	memset(ctx, 0, sizeof(*ctx));
    }
    free(ctx);
}

/**
 * Set the trust anchors in the verification context, makes an
 * reference to the keyset, so the consumer can free the keyset
 * independent of the destruction of the verification context (ctx).
 * If there already is a keyset attached, it's released.
 *
 * @param ctx a verification context
 * @param set a keyset containing the trust anchors.
 *
 * @ingroup hx509_verify
 */

void
hx509_verify_attach_anchors(hx509_verify_ctx ctx, hx509_certs set)
{
    if (ctx->trust_anchors)
	hx509_certs_free(&ctx->trust_anchors);
    ctx->trust_anchors = hx509_certs_ref(set);
}

/**
 * Attach an revocation context to the verfication context, , makes an
 * reference to the revoke context, so the consumer can free the
 * revoke context independent of the destruction of the verification
 * context. If there is no revoke context, the verification process is
 * NOT going to check any verification status.
 *
 * @param ctx a verification context.
 * @param revoke_ctx a revoke context.
 *
 * @ingroup hx509_verify
 */

void
hx509_verify_attach_revoke(hx509_verify_ctx ctx, hx509_revoke_ctx revoke_ctx)
{
    if (ctx->revoke_ctx)
	hx509_revoke_free(&ctx->revoke_ctx);
    ctx->revoke_ctx = _hx509_revoke_ref(revoke_ctx);
}

/**
 * Set the clock time the the verification process is going to
 * use. Used to check certificate in the past and future time. If not
 * set the current time will be used.
 *
 * @param ctx a verification context.
 * @param t the time the verifiation is using.
 *
 *
 * @ingroup hx509_verify
 */

void
hx509_verify_set_time(hx509_verify_ctx ctx, time_t t)
{
    ctx->flags |= HX509_VERIFY_CTX_F_TIME_SET;
    ctx->time_now = t;
}

time_t
_hx509_verify_get_time(hx509_verify_ctx ctx)
{
    return ctx->time_now;
}

/**
 * Set the maximum depth of the certificate chain that the path
 * builder is going to try.
 *
 * @param ctx a verification context
 * @param max_depth maxium depth of the certificate chain, include
 * trust anchor.
 *
 * @ingroup hx509_verify
 */

void
hx509_verify_set_max_depth(hx509_verify_ctx ctx, unsigned int max_depth)
{
    ctx->max_depth = max_depth;
}

/**
 * Allow or deny the use of proxy certificates
 *
 * @param ctx a verification context
 * @param boolean if non zero, allow proxy certificates.
 *
 * @ingroup hx509_verify
 */

void
hx509_verify_set_proxy_certificate(hx509_verify_ctx ctx, int boolean)
{
    if (boolean)
	ctx->flags |= HX509_VERIFY_CTX_F_ALLOW_PROXY_CERTIFICATE;
    else
	ctx->flags &= ~HX509_VERIFY_CTX_F_ALLOW_PROXY_CERTIFICATE;
}

/**
 * Select strict RFC3280 verification of certificiates. This means
 * checking key usage on CA certificates, this will make version 1
 * certificiates unuseable.
 *
 * @param ctx a verification context
 * @param boolean if non zero, use strict verification.
 *
 * @ingroup hx509_verify
 */

void
hx509_verify_set_strict_rfc3280_verification(hx509_verify_ctx ctx, int boolean)
{
    if (boolean)
	ctx->flags |= HX509_VERIFY_CTX_F_REQUIRE_RFC3280;
    else
	ctx->flags &= ~HX509_VERIFY_CTX_F_REQUIRE_RFC3280;
}

/**
 * Allow using the operating system builtin trust anchors if no other
 * trust anchors are configured.
 *
 * @param ctx a verification context
 * @param boolean if non zero, useing the operating systems builtin
 * trust anchors.
 *
 *
 * @ingroup hx509_cert
 */

void
hx509_verify_ctx_f_allow_default_trustanchors(hx509_verify_ctx ctx, int boolean)
{
    if (boolean)
	ctx->flags &= ~HX509_VERIFY_CTX_F_NO_DEFAULT_ANCHORS;
    else
	ctx->flags |= HX509_VERIFY_CTX_F_NO_DEFAULT_ANCHORS;
}

void
hx509_verify_ctx_f_allow_best_before_signature_algs(hx509_context ctx,
						    int boolean)
{
    if (boolean)
	ctx->flags &= ~HX509_VERIFY_CTX_F_NO_BEST_BEFORE_CHECK;
    else
	ctx->flags |= HX509_VERIFY_CTX_F_NO_BEST_BEFORE_CHECK;
}

static const Extension *
find_extension(const Certificate *cert, const heim_oid *oid, size_t *idx)
{
    const TBSCertificate *c = &cert->tbsCertificate;

    if (c->version == NULL || *c->version < 2 || c->extensions == NULL)
	return NULL;

    for (;*idx < c->extensions->len; (*idx)++) {
	if (der_heim_oid_cmp(&c->extensions->val[*idx].extnID, oid) == 0)
	    return &c->extensions->val[(*idx)++];
    }
    return NULL;
}

static int
find_extension_auth_key_id(const Certificate *subject,
			   AuthorityKeyIdentifier *ai)
{
    const Extension *e;
    size_t size;
    size_t i = 0;

    memset(ai, 0, sizeof(*ai));

    e = find_extension(subject, &asn1_oid_id_x509_ce_authorityKeyIdentifier, &i);
    if (e == NULL)
	return HX509_EXTENSION_NOT_FOUND;

    return decode_AuthorityKeyIdentifier(e->extnValue.data,
					 e->extnValue.length,
					 ai, &size);
}

int
_hx509_find_extension_subject_key_id(const Certificate *issuer,
				     SubjectKeyIdentifier *si)
{
    const Extension *e;
    size_t size;
    size_t i = 0;

    memset(si, 0, sizeof(*si));

    e = find_extension(issuer, &asn1_oid_id_x509_ce_subjectKeyIdentifier, &i);
    if (e == NULL)
	return HX509_EXTENSION_NOT_FOUND;

    return decode_SubjectKeyIdentifier(e->extnValue.data,
				       e->extnValue.length,
				       si, &size);
}

static int
find_extension_name_constraints(const Certificate *subject,
				NameConstraints *nc)
{
    const Extension *e;
    size_t size;
    size_t i = 0;

    memset(nc, 0, sizeof(*nc));

    e = find_extension(subject, &asn1_oid_id_x509_ce_nameConstraints, &i);
    if (e == NULL)
	return HX509_EXTENSION_NOT_FOUND;

    return decode_NameConstraints(e->extnValue.data,
				  e->extnValue.length,
				  nc, &size);
}

static int
find_extension_subject_alt_name(const Certificate *cert, size_t *i,
				GeneralNames *sa)
{
    const Extension *e;
    size_t size;

    memset(sa, 0, sizeof(*sa));

    e = find_extension(cert, &asn1_oid_id_x509_ce_subjectAltName, i);
    if (e == NULL)
	return HX509_EXTENSION_NOT_FOUND;

    return decode_GeneralNames(e->extnValue.data,
			       e->extnValue.length,
			       sa, &size);
}

static int
find_extension_eku(const Certificate *cert, ExtKeyUsage *eku)
{
    const Extension *e;
    size_t size;
    size_t i = 0;

    memset(eku, 0, sizeof(*eku));

    e = find_extension(cert, &asn1_oid_id_x509_ce_extKeyUsage, &i);
    if (e == NULL)
	return HX509_EXTENSION_NOT_FOUND;

    return decode_ExtKeyUsage(e->extnValue.data,
			      e->extnValue.length,
			      eku, &size);
}

static int
add_to_list(hx509_octet_string_list *list, const heim_octet_string *entry)
{
    void *p;
    int ret;

    p = realloc(list->val, (list->len + 1) * sizeof(list->val[0]));
    if (p == NULL)
	return ENOMEM;
    list->val = p;
    ret = der_copy_octet_string(entry, &list->val[list->len]);
    if (ret)
	return ret;
    list->len++;
    return 0;
}

/**
 * Free a list of octet strings returned by another hx509 library
 * function.
 *
 * @param list list to be freed.
 *
 * @ingroup hx509_misc
 */

void
hx509_free_octet_string_list(hx509_octet_string_list *list)
{
    size_t i;
    for (i = 0; i < list->len; i++)
	der_free_octet_string(&list->val[i]);
    free(list->val);
    list->val = NULL;
    list->len = 0;
}

/**
 * Return a list of subjectAltNames specified by oid in the
 * certificate. On error the
 *
 * The returned list of octet string should be freed with
 * hx509_free_octet_string_list().
 *
 * @param context A hx509 context.
 * @param cert a hx509 certificate object.
 * @param oid an oid to for SubjectAltName.
 * @param list list of matching SubjectAltName.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_find_subjectAltName_otherName(hx509_context context,
					 hx509_cert cert,
					 const heim_oid *oid,
					 hx509_octet_string_list *list)
{
    GeneralNames sa;
    int ret;
    size_t i, j;

    list->val = NULL;
    list->len = 0;

    i = 0;
    while (1) {
	ret = find_extension_subject_alt_name(_hx509_get_cert(cert), &i, &sa);
	i++;
	if (ret == HX509_EXTENSION_NOT_FOUND) {
	    return 0;
	} else if (ret != 0) {
	    hx509_set_error_string(context, 0, ret, "Error searching for SAN");
	    hx509_free_octet_string_list(list);
	    return ret;
	}

	for (j = 0; j < sa.len; j++) {
	    if (sa.val[j].element == choice_GeneralName_otherName &&
		der_heim_oid_cmp(&sa.val[j].u.otherName.type_id, oid) == 0)
	    {
		ret = add_to_list(list, &sa.val[j].u.otherName.value);
		if (ret) {
		    hx509_set_error_string(context, 0, ret,
					   "Error adding an exra SAN to "
					   "return list");
		    hx509_free_octet_string_list(list);
		    free_GeneralNames(&sa);
		    return ret;
		}
	    }
	}
	free_GeneralNames(&sa);
    }
}


static int
check_key_usage(hx509_context context, const Certificate *cert,
		unsigned flags, int req_present)
{
    const Extension *e;
    KeyUsage ku;
    size_t size;
    int ret;
    size_t i = 0;
    unsigned ku_flags;

    if (_hx509_cert_get_version(cert) < 3)
	return 0;

    e = find_extension(cert, &asn1_oid_id_x509_ce_keyUsage, &i);
    if (e == NULL) {
	if (req_present) {
	    hx509_set_error_string(context, 0, HX509_KU_CERT_MISSING,
				   "Required extension key "
				   "usage missing from certifiate");
	    return HX509_KU_CERT_MISSING;
	}
	return 0;
    }

    ret = decode_KeyUsage(e->extnValue.data, e->extnValue.length, &ku, &size);
    if (ret)
	return ret;
    ku_flags = KeyUsage2int(ku);
    if ((ku_flags & flags) != flags) {
	unsigned missing = (~ku_flags) & flags;
	char buf[256], *name;

	unparse_flags(missing, asn1_KeyUsage_units(), buf, sizeof(buf));
	_hx509_unparse_Name(&cert->tbsCertificate.subject, &name);
	hx509_set_error_string(context, 0, HX509_KU_CERT_MISSING,
			       "Key usage %s required but missing "
			       "from certifiate %s", buf, name);
	free(name);
	return HX509_KU_CERT_MISSING;
    }
    return 0;
}

/*
 * Return 0 on matching key usage 'flags' for 'cert', otherwise return
 * an error code. If 'req_present' the existance is required of the
 * KeyUsage extension.
 */

int
_hx509_check_key_usage(hx509_context context, hx509_cert cert,
		       unsigned flags, int req_present)
{
    return check_key_usage(context, _hx509_get_cert(cert), flags, req_present);
}

enum certtype { PROXY_CERT, EE_CERT, CA_CERT };

static int
check_basic_constraints(hx509_context context, const Certificate *cert,
			enum certtype type, size_t depth)
{
    BasicConstraints bc;
    const Extension *e;
    size_t size;
    int ret;
    size_t i = 0;

    if (_hx509_cert_get_version(cert) < 3)
	return 0;

    e = find_extension(cert, &asn1_oid_id_x509_ce_basicConstraints, &i);
    if (e == NULL) {
	switch(type) {
	case PROXY_CERT:
	case EE_CERT:
	    return 0;
	case CA_CERT: {
	    char *name;
	    ret = _hx509_unparse_Name(&cert->tbsCertificate.subject, &name);
	    assert(ret == 0);
	    hx509_set_error_string(context, 0, HX509_EXTENSION_NOT_FOUND,
				   "basicConstraints missing from "
				   "CA certifiacte %s", name);
	    free(name);
	    return HX509_EXTENSION_NOT_FOUND;
	}
	}
    }

    ret = decode_BasicConstraints(e->extnValue.data,
				  e->extnValue.length, &bc,
				  &size);
    if (ret)
	return ret;
    switch(type) {
    case PROXY_CERT:
	if (bc.cA != NULL && *bc.cA)
	    ret = HX509_PARENT_IS_CA;
	break;
    case EE_CERT:
	ret = 0;
	break;
    case CA_CERT:
	if (bc.cA == NULL || !*bc.cA)
	    ret = HX509_PARENT_NOT_CA;
	else if (bc.pathLenConstraint)
	    if (depth - 1 > *bc.pathLenConstraint)
		ret = HX509_CA_PATH_TOO_DEEP;
	break;
    }
    free_BasicConstraints(&bc);
    return ret;
}

int
_hx509_cert_is_parent_cmp(const Certificate *subject,
			  const Certificate *issuer,
			  int allow_self_signed)
{
    int diff;
    AuthorityKeyIdentifier ai;
    SubjectKeyIdentifier si;
    int ret_ai, ret_si, ret;

    ret = _hx509_name_cmp(&issuer->tbsCertificate.subject,
			  &subject->tbsCertificate.issuer,
			  &diff);
    if (ret)
	return ret;
    if (diff)
	return diff;

    memset(&ai, 0, sizeof(ai));
    memset(&si, 0, sizeof(si));

    /*
     * Try to find AuthorityKeyIdentifier, if it's not present in the
     * subject certificate nor the parent.
     */

    ret_ai = find_extension_auth_key_id(subject, &ai);
    if (ret_ai && ret_ai != HX509_EXTENSION_NOT_FOUND)
	return 1;
    ret_si = _hx509_find_extension_subject_key_id(issuer, &si);
    if (ret_si && ret_si != HX509_EXTENSION_NOT_FOUND)
	return -1;

    if (ret_si && ret_ai)
	goto out;
    if (ret_ai)
	goto out;
    if (ret_si) {
	if (allow_self_signed) {
	    diff = 0;
	    goto out;
	} else if (ai.keyIdentifier) {
	    diff = -1;
	    goto out;
	}
    }

    if (ai.keyIdentifier == NULL) {
	Name name;

	if (ai.authorityCertIssuer == NULL)
	    return -1;
	if (ai.authorityCertSerialNumber == NULL)
	    return -1;

	diff = der_heim_integer_cmp(ai.authorityCertSerialNumber,
				    &issuer->tbsCertificate.serialNumber);
	if (diff)
	    return diff;
	if (ai.authorityCertIssuer->len != 1)
	    return -1;
	if (ai.authorityCertIssuer->val[0].element != choice_GeneralName_directoryName)
	    return -1;

	name.element = (enum Name_enum)
	    ai.authorityCertIssuer->val[0].u.directoryName.element;
	name.u.rdnSequence =
	    ai.authorityCertIssuer->val[0].u.directoryName.u.rdnSequence;

	ret = _hx509_name_cmp(&issuer->tbsCertificate.subject,
			      &name,
			      &diff);
	if (ret)
	    return ret;
	if (diff)
	    return diff;
	diff = 0;
    } else
	diff = der_heim_octet_string_cmp(ai.keyIdentifier, &si);
    if (diff)
	goto out;

 out:
    free_AuthorityKeyIdentifier(&ai);
    free_SubjectKeyIdentifier(&si);
    return diff;
}

static int
certificate_is_anchor(hx509_context context,
		      hx509_certs trust_anchors,
		      const hx509_cert cert)
{
    hx509_query q;
    hx509_cert c;
    int ret;

    if (trust_anchors == NULL)
	return 0;

    _hx509_query_clear(&q);

    q.match = HX509_QUERY_MATCH_CERTIFICATE;
    q.certificate = _hx509_get_cert(cert);

    ret = hx509_certs_find(context, trust_anchors, &q, &c);
    if (ret == 0)
	hx509_cert_free(c);
    return ret == 0;
}

static int
certificate_is_self_signed(hx509_context context,
			   const Certificate *cert,
			   int *self_signed)
{
    int ret, diff;
    ret = _hx509_name_cmp(&cert->tbsCertificate.subject,
			  &cert->tbsCertificate.issuer, &diff);
    *self_signed = (diff == 0);
    if (ret) {
	hx509_set_error_string(context, 0, ret,
			       "Failed to check if self signed");
    } else
	ret = _hx509_self_signed_valid(context, &cert->signatureAlgorithm);

    return ret;
}

/*
 * The subjectName is "null" when it's empty set of relative DBs.
 */

static int
subject_null_p(const Certificate *c)
{
    return c->tbsCertificate.subject.u.rdnSequence.len == 0;
}


static int
find_parent(hx509_context context,
	    time_t time_now,
	    hx509_certs trust_anchors,
	    hx509_path *path,
	    hx509_certs pool,
	    hx509_cert current,
	    hx509_cert *parent)
{
    AuthorityKeyIdentifier ai;
    hx509_query q;
    int ret;

    *parent = NULL;
    memset(&ai, 0, sizeof(ai));

    _hx509_query_clear(&q);

    if (!subject_null_p(current->data)) {
	q.match |= HX509_QUERY_FIND_ISSUER_CERT;
	q.subject = _hx509_get_cert(current);
    } else {
	ret = find_extension_auth_key_id(current->data, &ai);
	if (ret) {
	    hx509_set_error_string(context, 0, HX509_CERTIFICATE_MALFORMED,
				   "Subjectless certificate missing AuthKeyID");
	    return HX509_CERTIFICATE_MALFORMED;
	}

	if (ai.keyIdentifier == NULL) {
	    free_AuthorityKeyIdentifier(&ai);
	    hx509_set_error_string(context, 0, HX509_CERTIFICATE_MALFORMED,
				   "Subjectless certificate missing keyIdentifier "
				   "inside AuthKeyID");
	    return HX509_CERTIFICATE_MALFORMED;
	}

	q.subject_id = ai.keyIdentifier;
	q.match = HX509_QUERY_MATCH_SUBJECT_KEY_ID;
    }

    q.path = path;
    q.match |= HX509_QUERY_NO_MATCH_PATH;

    if (pool) {
	q.timenow = time_now;
	q.match |= HX509_QUERY_MATCH_TIME;

	ret = hx509_certs_find(context, pool, &q, parent);
	if (ret == 0) {
	    free_AuthorityKeyIdentifier(&ai);
	    return 0;
	}
	q.match &= ~HX509_QUERY_MATCH_TIME;
    }

    if (trust_anchors) {
	ret = hx509_certs_find(context, trust_anchors, &q, parent);
	if (ret == 0) {
	    free_AuthorityKeyIdentifier(&ai);
	    return ret;
	}
    }
    free_AuthorityKeyIdentifier(&ai);

    {
	hx509_name name;
	char *str;

	ret = hx509_cert_get_subject(current, &name);
	if (ret) {
	    hx509_clear_error_string(context);
	    return HX509_ISSUER_NOT_FOUND;
	}
	ret = hx509_name_to_string(name, &str);
	hx509_name_free(&name);
	if (ret) {
	    hx509_clear_error_string(context);
	    return HX509_ISSUER_NOT_FOUND;
	}

	hx509_set_error_string(context, 0, HX509_ISSUER_NOT_FOUND,
			       "Failed to find issuer for "
			       "certificate with subject: '%s'", str);
	free(str);
    }
    return HX509_ISSUER_NOT_FOUND;
}

/*
 *
 */

static int
is_proxy_cert(hx509_context context,
	      const Certificate *cert,
	      ProxyCertInfo *rinfo)
{
    ProxyCertInfo info;
    const Extension *e;
    size_t size;
    int ret;
    size_t i = 0;

    if (rinfo)
	memset(rinfo, 0, sizeof(*rinfo));

    e = find_extension(cert, &asn1_oid_id_pkix_pe_proxyCertInfo, &i);
    if (e == NULL) {
	hx509_clear_error_string(context);
	return HX509_EXTENSION_NOT_FOUND;
    }

    ret = decode_ProxyCertInfo(e->extnValue.data,
			       e->extnValue.length,
			       &info,
			       &size);
    if (ret) {
	hx509_clear_error_string(context);
	return ret;
    }
    if (size != e->extnValue.length) {
	free_ProxyCertInfo(&info);
	hx509_clear_error_string(context);
	return HX509_EXTRA_DATA_AFTER_STRUCTURE;
    }
    if (rinfo == NULL)
	free_ProxyCertInfo(&info);
    else
	*rinfo = info;

    return 0;
}

/*
 * Path operations are like MEMORY based keyset, but with exposed
 * internal so we can do easy searches.
 */

int
_hx509_path_append(hx509_context context, hx509_path *path, hx509_cert cert)
{
    hx509_cert *val;
    val = realloc(path->val, (path->len + 1) * sizeof(path->val[0]));
    if (val == NULL) {
	hx509_set_error_string(context, 0, ENOMEM, "out of memory");
	return ENOMEM;
    }

    path->val = val;
    path->val[path->len] = hx509_cert_ref(cert);
    path->len++;

    return 0;
}

void
_hx509_path_free(hx509_path *path)
{
    unsigned i;

    for (i = 0; i < path->len; i++)
	hx509_cert_free(path->val[i]);
    free(path->val);
    path->val = NULL;
    path->len = 0;
}

/*
 * Find path by looking up issuer for the top certificate and continue
 * until an anchor certificate is found or max limit is found. A
 * certificate never included twice in the path.
 *
 * If the trust anchors are not given, calculate optimistic path, just
 * follow the chain upward until we no longer find a parent or we hit
 * the max path limit. In this case, a failure will always be returned
 * depending on what error condition is hit first.
 *
 * The path includes a path from the top certificate to the anchor
 * certificate.
 *
 * The caller needs to free `path´ both on successful built path and
 * failure.
 */

int
_hx509_calculate_path(hx509_context context,
		      int flags,
		      time_t time_now,
		      hx509_certs anchors,
		      unsigned int max_depth,
		      hx509_cert cert,
		      hx509_certs pool,
		      hx509_path *path)
{
    hx509_cert parent, current;
    int ret;

    if (max_depth == 0)
	max_depth = HX509_VERIFY_MAX_DEPTH;

    ret = _hx509_path_append(context, path, cert);
    if (ret)
	return ret;

    current = hx509_cert_ref(cert);

    while (!certificate_is_anchor(context, anchors, current)) {

	ret = find_parent(context, time_now, anchors, path,
			  pool, current, &parent);
	hx509_cert_free(current);
	if (ret)
	    return ret;

	ret = _hx509_path_append(context, path, parent);
	if (ret)
	    return ret;
	current = parent;

	if (path->len > max_depth) {
	    hx509_cert_free(current);
	    hx509_set_error_string(context, 0, HX509_PATH_TOO_LONG,
				   "Path too long while bulding "
				   "certificate chain");
	    return HX509_PATH_TOO_LONG;
	}
    }

    if ((flags & HX509_CALCULATE_PATH_NO_ANCHOR) &&
	path->len > 0 &&
	certificate_is_anchor(context, anchors, path->val[path->len - 1]))
    {
	hx509_cert_free(path->val[path->len - 1]);
	path->len--;
    }

    hx509_cert_free(current);
    return 0;
}

int
_hx509_AlgorithmIdentifier_cmp(const AlgorithmIdentifier *p,
			       const AlgorithmIdentifier *q)
{
    int diff;
    diff = der_heim_oid_cmp(&p->algorithm, &q->algorithm);
    if (diff)
	return diff;
    if (p->parameters) {
	if (q->parameters)
	    return heim_any_cmp(p->parameters,
				q->parameters);
	else
	    return 1;
    } else {
	if (q->parameters)
	    return -1;
	else
	    return 0;
    }
}

int
_hx509_Certificate_cmp(const Certificate *p, const Certificate *q)
{
    int diff;
    diff = der_heim_bit_string_cmp(&p->signatureValue, &q->signatureValue);
    if (diff)
	return diff;
    diff = _hx509_AlgorithmIdentifier_cmp(&p->signatureAlgorithm,
					  &q->signatureAlgorithm);
    if (diff)
	return diff;
    diff = der_heim_octet_string_cmp(&p->tbsCertificate._save,
				     &q->tbsCertificate._save);
    return diff;
}

/**
 * Compare to hx509 certificate object, useful for sorting.
 *
 * @param p a hx509 certificate object.
 * @param q a hx509 certificate object.
 *
 * @return 0 the objects are the same, returns > 0 is p is "larger"
 * then q, < 0 if p is "smaller" then q.
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_cmp(hx509_cert p, hx509_cert q)
{
    return _hx509_Certificate_cmp(p->data, q->data);
}

/**
 * Return the name of the issuer of the hx509 certificate.
 *
 * @param p a hx509 certificate object.
 * @param name a pointer to a hx509 name, should be freed by
 * hx509_name_free().
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_get_issuer(hx509_cert p, hx509_name *name)
{
    return hx509_name_from_Name(&p->data->tbsCertificate.issuer, name);
}

/**
 * Return the name of the subject of the hx509 certificate.
 *
 * @param p a hx509 certificate object.
 * @param name a pointer to a hx509 name, should be freed by
 * hx509_name_free(). See also hx509_cert_get_base_subject().
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_get_subject(hx509_cert p, hx509_name *name)
{
    return hx509_name_from_Name(&p->data->tbsCertificate.subject, name);
}

/**
 * Return the name of the base subject of the hx509 certificate. If
 * the certiicate is a verified proxy certificate, the this function
 * return the base certificate (root of the proxy chain). If the proxy
 * certificate is not verified with the base certificate
 * HX509_PROXY_CERTIFICATE_NOT_CANONICALIZED is returned.
 *
 * @param context a hx509 context.
 * @param c a hx509 certificate object.
 * @param name a pointer to a hx509 name, should be freed by
 * hx509_name_free(). See also hx509_cert_get_subject().
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_get_base_subject(hx509_context context, hx509_cert c,
			    hx509_name *name)
{
    if (c->basename)
	return hx509_name_copy(context, c->basename, name);
    if (is_proxy_cert(context, c->data, NULL) == 0) {
	int ret = HX509_PROXY_CERTIFICATE_NOT_CANONICALIZED;
	hx509_set_error_string(context, 0, ret,
			       "Proxy certificate have not been "
			       "canonicalize yet, no base name");
	return ret;
    }
    return hx509_name_from_Name(&c->data->tbsCertificate.subject, name);
}

/**
 * Get serial number of the certificate.
 *
 * @param p a hx509 certificate object.
 * @param i serial number, should be freed ith der_free_heim_integer().
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_get_serialnumber(hx509_cert p, heim_integer *i)
{
    return der_copy_heim_integer(&p->data->tbsCertificate.serialNumber, i);
}

/**
 * Get notBefore time of the certificate.
 *
 * @param p a hx509 certificate object.
 *
 * @return return not before time
 *
 * @ingroup hx509_cert
 */

time_t
hx509_cert_get_notBefore(hx509_cert p)
{
    return _hx509_Time2time_t(&p->data->tbsCertificate.validity.notBefore);
}

/**
 * Get notAfter time of the certificate.
 *
 * @param p a hx509 certificate object.
 *
 * @return return not after time.
 *
 * @ingroup hx509_cert
 */

time_t
hx509_cert_get_notAfter(hx509_cert p)
{
    return _hx509_Time2time_t(&p->data->tbsCertificate.validity.notAfter);
}

/**
 * Get the SubjectPublicKeyInfo structure from the hx509 certificate.
 *
 * @param context a hx509 context.
 * @param p a hx509 certificate object.
 * @param spki SubjectPublicKeyInfo, should be freed with
 * free_SubjectPublicKeyInfo().
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_get_SPKI(hx509_context context, hx509_cert p, SubjectPublicKeyInfo *spki)
{
    int ret;

    ret = copy_SubjectPublicKeyInfo(&p->data->tbsCertificate.subjectPublicKeyInfo, spki);
    if (ret)
	hx509_set_error_string(context, 0, ret, "Failed to copy SPKI");
    return ret;
}

/**
 * Get the AlgorithmIdentifier from the hx509 certificate.
 *
 * @param context a hx509 context.
 * @param p a hx509 certificate object.
 * @param alg AlgorithmIdentifier, should be freed with
 *            free_AlgorithmIdentifier(). The algorithmidentifier is
 *            typicly rsaEncryption, or id-ecPublicKey, or some other
 *            public key mechanism.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_get_SPKI_AlgorithmIdentifier(hx509_context context,
					hx509_cert p,
					AlgorithmIdentifier *alg)
{
    int ret;

    ret = copy_AlgorithmIdentifier(&p->data->tbsCertificate.subjectPublicKeyInfo.algorithm, alg);
    if (ret)
	hx509_set_error_string(context, 0, ret,
			       "Failed to copy SPKI AlgorithmIdentifier");
    return ret;
}

static int
get_x_unique_id(hx509_context context, const char *name,
		const heim_bit_string *cert, heim_bit_string *subject)
{
    int ret;

    if (cert == NULL) {
	ret = HX509_EXTENSION_NOT_FOUND;
	hx509_set_error_string(context, 0, ret, "%s unique id doesn't exists", name);
	return ret;
    }
    ret = der_copy_bit_string(cert, subject);
    if (ret) {
	hx509_set_error_string(context, 0, ret, "malloc out of memory");
	return ret;
    }
    return 0;
}

/**
 * Get a copy of the Issuer Unique ID
 *
 * @param context a hx509_context
 * @param p a hx509 certificate
 * @param issuer the issuer id returned, free with der_free_bit_string()
 *
 * @return An hx509 error code, see hx509_get_error_string(). The
 * error code HX509_EXTENSION_NOT_FOUND is returned if the certificate
 * doesn't have a issuerUniqueID
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_get_issuer_unique_id(hx509_context context, hx509_cert p, heim_bit_string *issuer)
{
    return get_x_unique_id(context, "issuer", p->data->tbsCertificate.issuerUniqueID, issuer);
}

/**
 * Get a copy of the Subect Unique ID
 *
 * @param context a hx509_context
 * @param p a hx509 certificate
 * @param subject the subject id returned, free with der_free_bit_string()
 *
 * @return An hx509 error code, see hx509_get_error_string(). The
 * error code HX509_EXTENSION_NOT_FOUND is returned if the certificate
 * doesn't have a subjectUniqueID
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_get_subject_unique_id(hx509_context context, hx509_cert p, heim_bit_string *subject)
{
    return get_x_unique_id(context, "subject", p->data->tbsCertificate.subjectUniqueID, subject);
}


hx509_private_key
_hx509_cert_private_key(hx509_cert p)
{
    return p->private_key;
}

int
hx509_cert_have_private_key(hx509_cert p)
{
    return p->private_key ? 1 : 0;
}


int
_hx509_cert_private_key_exportable(hx509_cert p)
{
    if (p->private_key == NULL)
	return 0;
    return _hx509_private_key_exportable(p->private_key);
}

int
_hx509_cert_private_decrypt(hx509_context context,
			    const heim_octet_string *ciphertext,
			    const heim_oid *encryption_oid,
			    hx509_cert p,
			    heim_octet_string *cleartext)
{
    cleartext->data = NULL;
    cleartext->length = 0;

    if (p->private_key == NULL) {
	hx509_set_error_string(context, 0, HX509_PRIVATE_KEY_MISSING,
			       "Private key missing");
	return HX509_PRIVATE_KEY_MISSING;
    }

    return hx509_private_key_private_decrypt(context,
					      ciphertext,
					      encryption_oid,
					      p->private_key,
					      cleartext);
}

int
hx509_cert_public_encrypt(hx509_context context,
			   const heim_octet_string *cleartext,
			   const hx509_cert p,
			   heim_oid *encryption_oid,
			   heim_octet_string *ciphertext)
{
    return _hx509_public_encrypt(context,
				 cleartext, p->data,
				 encryption_oid, ciphertext);
}

/*
 *
 */

time_t
_hx509_Time2time_t(const Time *t)
{
    switch(t->element) {
    case choice_Time_utcTime:
	return t->u.utcTime;
    case choice_Time_generalTime:
	return t->u.generalTime;
    case invalid_choice_Time:
	return 0;
    }
}

static void
evaluate_free(heim_object_t object)
{
    hx509_evaluate data = object;
    heim_release(data->path);
}

hx509_evaluate
_hx509_evaluate_alloc(void)
{
    hx509_evaluate eval;

    eval = heim_uniq_alloc(sizeof(*eval), "hx509-evaluate", evaluate_free);
    if (eval == NULL)
	return NULL;

    eval->path = heim_array_create();
    if (eval->path == NULL) {
	heim_release(eval);
	return NULL;
    }
    return eval;
}

size_t
hx509_evaluate_get_length(hx509_evaluate data)
{
    return heim_array_get_length(data->path);
}

hx509_cert
hx509_evaluate_get_cert(hx509_evaluate data, size_t offset)
{
    return heim_array_copy_value(data->path, offset);
}

hx509_cert
hx509_evaluate_get_ta(hx509_evaluate data)
{
    size_t len = heim_array_get_length(data->path);
    if (len == 0)
	return NULL;
    return heim_array_copy_value(data->path, len - 1);
}

void
hx509_evaluate_free(hx509_evaluate data)
{
    heim_release(data);
}

/*
 *
 */

static int
init_name_constraints(hx509_name_constraints *nc)
{
    memset(nc, 0, sizeof(*nc));
    return 0;
}

static int
add_name_constraints(hx509_context context, const Certificate *c, int not_ca,
		     hx509_name_constraints *nc)
{
    NameConstraints tnc;
    int ret;

    ret = find_extension_name_constraints(c, &tnc);
    if (ret == HX509_EXTENSION_NOT_FOUND)
	return 0;
    else if (ret) {
	hx509_set_error_string(context, 0, ret, "Failed getting NameConstraints");
	return ret;
    } else if (not_ca) {
	ret = HX509_VERIFY_CONSTRAINTS;
	hx509_set_error_string(context, 0, ret, "Not a CA and "
			       "have NameConstraints");
    } else {
	NameConstraints *val;
	val = realloc(nc->val, sizeof(nc->val[0]) * (nc->len + 1));
	if (val == NULL) {
	    hx509_clear_error_string(context);
	    ret = ENOMEM;
	    goto out;
	}
	nc->val = val;
	ret = copy_NameConstraints(&tnc, &nc->val[nc->len]);
	if (ret) {
	    hx509_clear_error_string(context);
	    goto out;
	}
	nc->len += 1;
    }
out:
    free_NameConstraints(&tnc);
    return ret;
}

static int
match_RDN(const RelativeDistinguishedName *c,
	  const RelativeDistinguishedName *n)
{
    size_t i;

    if (c->len != n->len)
	return HX509_NAME_CONSTRAINT_ERROR;

    for (i = 0; i < n->len; i++) {
	int diff, ret;

	if (der_heim_oid_cmp(&c->val[i].type, &n->val[i].type) != 0)
	    return HX509_NAME_CONSTRAINT_ERROR;
	ret = _hx509_name_ds_cmp(&c->val[i].value, &n->val[i].value, &diff);
	if (ret)
	    return ret;
	if (diff != 0)
	    return HX509_NAME_CONSTRAINT_ERROR;
    }
    return 0;
}

static int
match_X501Name(const Name *c, const Name *n)
{
    size_t i;
    int ret;

    if (c->element != choice_Name_rdnSequence
	|| n->element != choice_Name_rdnSequence)
	return 0;
    if (c->u.rdnSequence.len > n->u.rdnSequence.len)
	return HX509_NAME_CONSTRAINT_ERROR;
    for (i = 0; i < c->u.rdnSequence.len; i++) {
	ret = match_RDN(&c->u.rdnSequence.val[i], &n->u.rdnSequence.val[i]);
	if (ret)
	    return ret;
    }
    return 0;
}


static int
match_general_name(const GeneralName *c, const GeneralName *n, int *match)
{
    /*
     * Name constraints only apply to the same name type, see RFC3280,
     * 4.2.1.11.
     */
    assert(c->element == n->element);

    switch(c->element) {
    case choice_GeneralName_otherName:
	if (der_heim_oid_cmp(&c->u.otherName.type_id,
			 &n->u.otherName.type_id) != 0)
	    return HX509_NAME_CONSTRAINT_ERROR;
	if (heim_any_cmp(&c->u.otherName.value,
			 &n->u.otherName.value) != 0)
	    return HX509_NAME_CONSTRAINT_ERROR;
	*match = 1;
	return 0;
    case choice_GeneralName_rfc822Name: {
	const char *s;
	size_t len1, len2;
	s = memchr(c->u.rfc822Name.data, '@', c->u.rfc822Name.length);
	if (s) {
	    if (der_printable_string_cmp(&c->u.rfc822Name, &n->u.rfc822Name) != 0)
		return HX509_NAME_CONSTRAINT_ERROR;
	} else {
	    s = memchr(n->u.rfc822Name.data, '@', n->u.rfc822Name.length);
	    if (s == NULL)
		return HX509_NAME_CONSTRAINT_ERROR;
	    len1 = c->u.rfc822Name.length;
	    len2 = n->u.rfc822Name.length -
		(s - ((char *)n->u.rfc822Name.data));
	    if (len1 > len2)
		return HX509_NAME_CONSTRAINT_ERROR;
	    if (memcmp(s + 1 + len2 - len1, c->u.rfc822Name.data, len1) != 0)
		return HX509_NAME_CONSTRAINT_ERROR;
	    if (len1 < len2 && s[len2 - len1 + 1] != '.')
		return HX509_NAME_CONSTRAINT_ERROR;
	}
	*match = 1;
	return 0;
    }
    case choice_GeneralName_dNSName: {
	size_t lenc, lenn;
	char *ptr;

	lenc = c->u.dNSName.length;
	lenn = n->u.dNSName.length;
	if (lenc > lenn)
	    return HX509_NAME_CONSTRAINT_ERROR;
	ptr = n->u.dNSName.data;
	if (memcmp(&ptr[lenn - lenc], c->u.dNSName.data, lenc) != 0)
	    return HX509_NAME_CONSTRAINT_ERROR;
	if (lenn != lenc && ptr[lenn - lenc - 1] != '.')
	    return HX509_NAME_CONSTRAINT_ERROR;
	*match = 1;
	return 0;
    }
    case choice_GeneralName_directoryName: {
	Name c_name, n_name;
	int ret;

	c_name._save.data = NULL;
	c_name._save.length = 0;
	c_name.element = (enum Name_enum)c->u.directoryName.element;
	c_name.u.rdnSequence = c->u.directoryName.u.rdnSequence;

	n_name._save.data = NULL;
	n_name._save.length = 0;
	n_name.element = (enum Name_enum)n->u.directoryName.element;
	n_name.u.rdnSequence = n->u.directoryName.u.rdnSequence;

	ret = match_X501Name(&c_name, &n_name);
	if (ret == 0)
	    *match = 1;
	return ret;
    }
    case choice_GeneralName_uniformResourceIdentifier:
    case choice_GeneralName_iPAddress:
    case choice_GeneralName_registeredID:
    case invalid_choice_GeneralName:
	return HX509_NAME_CONSTRAINT_ERROR;
    }
}

static int
match_alt_name(const GeneralName *n, const Certificate *c,
	       int *same, int *match)
{
    GeneralNames sa;
    int ret;
    size_t i, j;

    i = 0;
    do {
	ret = find_extension_subject_alt_name(c, &i, &sa);
	if (ret == HX509_EXTENSION_NOT_FOUND) {
	    ret = 0;
	    break;
	} else if (ret != 0)
	    break;

	for (j = 0; j < sa.len; j++) {
	    if (n->element == sa.val[j].element) {
		*same = 1;
		(void)match_general_name(n, &sa.val[j], match);
	    }
	}
	free_GeneralNames(&sa);
    } while (1);
    return ret;
}


static int
match_tree(const GeneralSubtrees *t, const Certificate *c, int *match)
{
    int name, alt_name, same;
    unsigned int i;
    int ret = 0;

    name = alt_name = same = *match = 0;
    for (i = 0; i < t->len; i++) {
	if (t->val[i].minimum && t->val[i].maximum)
	    return HX509_RANGE;

	/*
	 * If the constraint apply to directoryNames, test is with
	 * subjectName of the certificate if the certificate have a
	 * non-null (empty) subjectName.
	 */

	if (t->val[i].base.element == choice_GeneralName_directoryName
	    && !subject_null_p(c))
	{
	    GeneralName certname;

	    memset(&certname, 0, sizeof(certname));
	    certname.element = choice_GeneralName_directoryName;
	    certname.u.directoryName.element =
		(enum GeneralName_directoryName_enum)c->tbsCertificate.subject.element;
	    certname.u.directoryName.u.rdnSequence =
		c->tbsCertificate.subject.u.rdnSequence;

	    (void)match_general_name(&t->val[i].base, &certname, &name);
	}

	/* Handle subjectAltNames, this is icky since they
	 * restrictions only apply if the subjectAltName is of the
	 * same type. So if there have been a match of type, require
	 * altname to be set.
	 */
	ret = match_alt_name(&t->val[i].base, c, &same, &alt_name);
    }
    if (name && (!same || alt_name))
	*match = 1;
    return ret;
}

static int
check_name_constraints(hx509_context context,
		       const hx509_name_constraints *nc,
		       const Certificate *c)
{
    int match, ret;
    size_t i;

    for (i = 0 ; i < nc->len; i++) {
	GeneralSubtrees gs;

	if (nc->val[i].permittedSubtrees) {
	    GeneralSubtrees_SET(&gs, nc->val[i].permittedSubtrees);
	    ret = match_tree(&gs, c, &match);
	    if (ret) {
		hx509_clear_error_string(context);
		return ret;
	    }
	    /* allow null subjectNames, they wont matches anything */
	    if (match == 0 && !subject_null_p(c)) {
		hx509_set_error_string(context, 0, HX509_VERIFY_CONSTRAINTS,
				       "Error verify constraints, "
				       "certificate didn't match any "
				       "permitted subtree");
		return HX509_VERIFY_CONSTRAINTS;
	    }
	}
	if (nc->val[i].excludedSubtrees) {
	    GeneralSubtrees_SET(&gs, nc->val[i].excludedSubtrees);
	    ret = match_tree(&gs, c, &match);
	    if (ret) {
		hx509_clear_error_string(context);
		return ret;
	    }
	    if (match) {
		hx509_set_error_string(context, 0, HX509_VERIFY_CONSTRAINTS,
				       "Error verify constraints, "
				       "certificate included in excluded "
				       "subtree");
		return HX509_VERIFY_CONSTRAINTS;
	    }
	}
    }
    return 0;
}

static void
free_name_constraints(hx509_name_constraints *nc)
{
    size_t i;

    for (i = 0 ; i < nc->len; i++)
	free_NameConstraints(&nc->val[i]);
    free(nc->val);
}

/**
 * Build and verify the path for the certificate to the trust anchor
 * specified in the verify context. The path is constructed from the
 * certificate, the pool and the trust anchors.
 *
 * @param context A hx509 context.
 * @param ctx A hx509 verification context.
 * @param cert the certificate to build the path from.
 * @param pool A keyset of certificates to build the chain from.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_verify
 */

static int
_hx509_verify_path_internal(hx509_context context,
			    hx509_verify_ctx ctx,
			    hx509_cert cert,
			    hx509_certs pool,
			    hx509_evaluate *result)
{
    hx509_name_constraints nc;
    hx509_path path;
    int ret, proxy_cert_depth, selfsigned_depth, diff;
    size_t i, k;
    enum certtype type;
    Name proxy_issuer;
    hx509_certs anchors = NULL;

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

    if (result)
	*result = NULL;

    ret = init_name_constraints(&nc);
    if (ret)
	return ret;

    path.val = NULL;
    path.len = 0;

    if ((ctx->flags & HX509_VERIFY_CTX_F_TIME_SET) == 0)
	ctx->time_now = time(NULL);

    /*
     *
     */
    if (ctx->trust_anchors)
	anchors = hx509_certs_ref(ctx->trust_anchors);
    else if (context->default_trust_anchors && ALLOW_DEF_TA(ctx))
	anchors = hx509_certs_ref(context->default_trust_anchors);
    else {
	ret = hx509_certs_init(context, "MEMORY:no-TA", 0, NULL, &anchors);
	if (ret)
	    goto out;
    }

    /*
     * Calculate the path from the certificate user presented to the
     * to an anchor.
     */
    ret = _hx509_calculate_path(context, 0, ctx->time_now,
				anchors, ctx->max_depth,
				cert, pool, &path);
    if (ret)
	goto out;

    /*
     * Check CA and proxy certificate chain from the top of the
     * certificate chain. Also check certificate is valid with respect
     * to the current time.
     *
     */

    proxy_cert_depth = 0;
    selfsigned_depth = 0;

    if (ctx->flags & HX509_VERIFY_CTX_F_ALLOW_PROXY_CERTIFICATE)
	type = PROXY_CERT;
    else
	type = EE_CERT;

    for (i = 0; i < path.len; i++) {
	Certificate *c;
	time_t t;

	c = _hx509_get_cert(path.val[i]);

	/*
	 * Lets do some basic check on issuer like
	 * keyUsage.keyCertSign and basicConstraints.cA bit depending
	 * on what type of certificate this is.
	 */

	switch (type) {
	case CA_CERT:

	    /* XXX make constants for keyusage */
	    ret = check_key_usage(context, c, 1 << 5,
				  REQUIRE_RFC3280(ctx) ? TRUE : FALSE);
	    if (ret) {
		hx509_set_error_string(context, HX509_ERROR_APPEND, ret,
				       "Key usage missing from CA certificate");
		goto out;
	    }

	    /* self signed cert doesn't add to path length */
	    if (i + 1 != path.len) {
		int selfsigned;

		ret = certificate_is_self_signed(context, c, &selfsigned);
		if (ret)
		    goto out;
		if (selfsigned)
		    selfsigned_depth++;
	    }

	    break;
	case PROXY_CERT: {
	    ProxyCertInfo info;

	    if (is_proxy_cert(context, c, &info) == 0) {
		size_t j;

		if (info.pCPathLenConstraint != NULL &&
		    *info.pCPathLenConstraint < i)
		{
		    free_ProxyCertInfo(&info);
		    ret = HX509_PATH_TOO_LONG;
		    hx509_set_error_string(context, 0, ret,
					   "Proxy certificate chain "
					   "longer then allowed");
		    goto out;
		}
		/* XXX MUST check info.proxyPolicy */
		free_ProxyCertInfo(&info);

		j = 0;
		if (find_extension(c, &asn1_oid_id_x509_ce_subjectAltName, &j)) {
		    ret = HX509_PROXY_CERT_INVALID;
		    hx509_set_error_string(context, 0, ret,
					   "Proxy certificate have explicity "
					   "forbidden subjectAltName");
		    goto out;
		}

		j = 0;
		if (find_extension(c, &asn1_oid_id_x509_ce_issuerAltName, &j)) {
		    ret = HX509_PROXY_CERT_INVALID;
		    hx509_set_error_string(context, 0, ret,
					   "Proxy certificate have explicity "
					   "forbidden issuerAltName");
		    goto out;
		}

		/*
		 * The subject name of the proxy certificate should be
		 * CN=XXX,<proxy issuer>, prune of CN and check if its
		 * the same over the whole chain of proxy certs and
		 * then check with the EE cert when we get to it.
		 */

		if (proxy_cert_depth) {
		    ret = _hx509_name_cmp(&proxy_issuer, &c->tbsCertificate.subject, &diff);
		    if (ret) {
			hx509_set_error_string(context, 0, ret, "Out of memory");
			goto out;
		    }
		    if (diff) {
			ret = HX509_PROXY_CERT_NAME_WRONG;
			hx509_set_error_string(context, 0, ret,
					       "Base proxy name not right");
			goto out;
		    }
		}

		free_Name(&proxy_issuer);

		ret = copy_Name(&c->tbsCertificate.subject, &proxy_issuer);
		if (ret) {
		    hx509_clear_error_string(context);
		    goto out;
		}

		j = proxy_issuer.u.rdnSequence.len;
		if (proxy_issuer.u.rdnSequence.len < 2
		    || proxy_issuer.u.rdnSequence.val[j - 1].len > 1
		    || der_heim_oid_cmp(&proxy_issuer.u.rdnSequence.val[j - 1].val[0].type,
					&asn1_oid_id_at_commonName))
		{
		    ret = HX509_PROXY_CERT_NAME_WRONG;
		    hx509_set_error_string(context, 0, ret,
					   "Proxy name too short or "
					   "does not have Common name "
					   "at the top");
		    goto out;
		}

		free_RelativeDistinguishedName(&proxy_issuer.u.rdnSequence.val[j - 1]);
		proxy_issuer.u.rdnSequence.len -= 1;

		ret = _hx509_name_cmp(&proxy_issuer, &c->tbsCertificate.issuer, &diff);
		if (ret) {
		    hx509_set_error_string(context, 0, ret, "Out of memory");
		    goto out;
		}
		if (diff != 0) {
		    ret = HX509_PROXY_CERT_NAME_WRONG;
		    hx509_set_error_string(context, 0, ret,
					   "Proxy issuer name not as expected");
		    goto out;
		}

		break;
	    } else {
		/*
		 * Now we are done with the proxy certificates, this
		 * cert was an EE cert and we we will fall though to
		 * EE checking below.
		 */
		type = EE_CERT;
		/* FALLTHOUGH */
	    }
	}
	case EE_CERT:
	    /*
	     * If there where any proxy certificates in the chain
	     * (proxy_cert_depth > 0), check that the proxy issuer
	     * matched proxy certificates "base" subject.
	     */
	    if (proxy_cert_depth) {

		ret = _hx509_name_cmp(&proxy_issuer,
				      &c->tbsCertificate.subject, &diff);
		if (ret) {
		    hx509_set_error_string(context, 0, ret, "out of memory");
		    goto out;
		}
		if (diff) {
		    ret = HX509_PROXY_CERT_NAME_WRONG;
		    hx509_clear_error_string(context);
		    goto out;
		}
		if (cert->basename)
		    hx509_name_free(&cert->basename);

		ret = hx509_name_from_Name(&proxy_issuer, &cert->basename);
		if (ret) {
		    hx509_clear_error_string(context);
		    goto out;
		}
	    }

	    break;
	}

	ret = check_basic_constraints(context, c, type,
				      i - proxy_cert_depth - selfsigned_depth);
	if (ret)
	    goto out;

	/*
	 * Don't check the trust anchors expiration time since they
	 * are transported out of band, from RFC3820.
	 */
	if (i + 1 != path.len || CHECK_TA(ctx)) {

	    t = _hx509_Time2time_t(&c->tbsCertificate.validity.notBefore);
	    if (t > ctx->time_now) {
		ret = HX509_CERT_USED_BEFORE_TIME;
		hx509_clear_error_string(context);
		goto out;
	    }
	    t = _hx509_Time2time_t(&c->tbsCertificate.validity.notAfter);
	    if (t < ctx->time_now) {
		ret = HX509_CERT_USED_AFTER_TIME;
		hx509_clear_error_string(context);
		goto out;
	    }
	}

	if (type == EE_CERT)
	    type = CA_CERT;
	else if (type == PROXY_CERT)
	    proxy_cert_depth++;
    }

    /*
     * Verify constraints, do this backward so path constraints are
     * checked in the right order.
     */

    for (ret = 0, k = path.len; k > 0; k--) {
	Certificate *c;
	int selfsigned;
	i = k - 1;

	c = _hx509_get_cert(path.val[i]);

	ret = certificate_is_self_signed(context, c, &selfsigned);
	if (ret)
	    goto out;

	/* verify name constraints, not for selfsigned and anchor */
	if (!selfsigned || i + 1 != path.len) {
	    ret = check_name_constraints(context, &nc, c);
	    if (ret) {
		goto out;
	    }
	}
	ret = add_name_constraints(context, c, i == 0, &nc);
	if (ret)
	    goto out;

	/* XXX verify all other silly constraints */

    }

    /*
     * Verify that no certificates has been revoked.
     */

    if (ctx->revoke_ctx) {
	hx509_certs certs;

	ret = hx509_certs_init(context, "MEMORY:revoke-certs", 0,
			       NULL, &certs);
	if (ret)
	    goto out;

	for (i = 0; i < path.len; i++) {
	    ret = hx509_certs_add(context, certs, path.val[i]);
	    if (ret) {
		hx509_certs_free(&certs);
		goto out;
	    }
	}
	ret = hx509_certs_merge(context, certs, pool);
	if (ret) {
	    hx509_certs_free(&certs);
	    goto out;
	}

	for (i = 0; i < path.len - 1; i++) {
	    size_t parent = (i < path.len - 1) ? i + 1 : i;

	    ret = hx509_revoke_verify(context,
				      ctx->revoke_ctx,
				      certs,
				      ctx->time_now,
				      path.val[i],
				      path.val[parent]);
	    if (ret) {
		hx509_certs_free(&certs);
		goto out;
	    }
	}
	hx509_certs_free(&certs);
    }

    /*
     * Verify signatures, do this backward so public key working
     * parameter is passed up from the anchor up though the chain.
     */

    for (k = path.len; k > 0; k--) {
	hx509_cert signer;
	Certificate *c;
	i = k - 1;

	c = _hx509_get_cert(path.val[i]);

	/* is last in chain (trust anchor) */
	if (i + 1 == path.len) {
	    int selfsigned;

	    signer = path.val[i];

	    ret = certificate_is_self_signed(context, signer->data, &selfsigned);
	    if (ret)
		goto out;

	    /* if trust anchor is not self signed, don't check sig */
	    if (!selfsigned)
		continue;
	} else {
	    /* take next certificate in chain */
	    signer = path.val[i + 1];
	}

	/* verify signatureValue */
	ret = _hx509_verify_signature_bitstring(context,
						signer,
						&c->signatureAlgorithm,
						&c->tbsCertificate._save,
						&c->signatureValue);
	if (ret) {
	    hx509_set_error_string(context, HX509_ERROR_APPEND, ret,
				   "Failed to verify signature of certificate");
	    goto out;
	}
	/*
	 * Verify that the sigature algorithm "best-before" date is
	 * before the creation date of the certificate, do this for
	 * trust anchors too, since any trust anchor that is created
	 * after a algorithm is known to be bad deserved to be invalid.
	 *
	 * Skip the leaf certificate for now...
	 */

	if (i != 0 && (ctx->flags & HX509_VERIFY_CTX_F_NO_BEST_BEFORE_CHECK) == 0) {
	    time_t notBefore =
		_hx509_Time2time_t(&c->tbsCertificate.validity.notBefore);
	    ret = _hx509_signature_best_before(context,
					       &c->signatureAlgorithm,
					       notBefore);
	    if (ret)
		goto out;
	}
    }

    if (result) {
	*result = _hx509_evaluate_alloc();
	if (*result == NULL) {
	    ret = ENOMEM;
	    goto out;
	}

	for (i = 0; i < path.len; i++)
	    heim_array_append_value((*result)->path, path.val[i]);
    }

out:
    hx509_certs_free(&anchors);
    free_Name(&proxy_issuer);
    free_name_constraints(&nc);
    _hx509_path_free(&path);

    return ret;
}

/**
  * Build and verify the path for the certificate to the trust anchor
  * specified in the verify context. The path is constructed from the
  * certificate, the pool and the trust anchors.
  *
  * @param context A hx509 context.
  * @param ctx A hx509 verification context.
  * @param cert the certificate to build the path from.
  * @param pool A keyset of certificates to build the chain from.
  *
  * @return An hx509 error code, see hx509_get_error_string().
  *
  * @ingroup hx509_verify
  */

int
hx509_verify_path(hx509_context context,
		  hx509_verify_ctx ctx,
		  hx509_cert cert,
		  hx509_certs pool)
{
    return hx509_evaluate_cert(context, ctx, cert, pool, NULL);
}

#ifdef __APPLE__
#include <Security/Security.h>

static SecCertificateRef
HXCreateCertificateFromHX509Certificate(hx509_context context, hx509_cert cert)
{
    SecCertificateRef c = NULL;
    heim_octet_string os;
    int r;

    r = hx509_cert_binary(context, cert, &os);
    if (r)
	return NULL;

    CFDataRef refdata = CFDataCreateWithBytesNoCopy(NULL, os.data, os.length, kCFAllocatorNull);
    if (refdata) {
	c = SecCertificateCreateWithData(NULL, refdata);
	CFRelease(refdata);
    }
    hx509_xfree(os.data);
    return c;
}

#endif


int
hx509_evaluate_cert(hx509_context context,
		    hx509_verify_ctx ctx,
		    hx509_cert cert,
		    hx509_certs pool,
		    hx509_evaluate *validate)
{
#ifdef __APPLE__
    __block CFMutableArrayRef certs;
    __block SecCertificateRef c;
    int ret;

    if (validate)
	*validate = NULL;

    certs = CFArrayCreateMutable(NULL, 0, &kCFTypeArrayCallBacks);
    heim_assert(certs != NULL, "out of memory");

    c = HXCreateCertificateFromHX509Certificate(context, cert);
    CFArrayAppendValue(certs, c);
    CFRelease(c);

    hx509_certs_iter(context, pool, ^(hx509_cert pc) {
	    c = HXCreateCertificateFromHX509Certificate(context, pc);
	    CFArrayAppendValue(certs, c);
	    CFRelease(c);
	    return 0;
	});

    /* XXX pkinit policy */
    SecPolicyRef policy = SecPolicyCreateBasicX509();

    SecTrustRef trust = NULL;

    OSStatus status = SecTrustCreateWithCertificates(certs, policy, &trust);
    CFRelease(policy);
    CFRelease(certs);
    if (status) {
	ret = HX509_ISSUER_NOT_FOUND;
	hx509_set_error_string(context, 0, ret, "Failed to create trust");
	CFRelease(trust);
    }

    SecTrustResultType result;

    status = SecTrustEvaluate(trust, &result);
    if (status) {
	ret = HX509_ISSUER_NOT_FOUND;
	hx509_set_error_string(context, 0, ret, "Failed to validate trust: %d", (int)status);
	CFRelease(trust);
	return ret;
    }

    switch (result) {
    case kSecTrustResultUnspecified:
    case kSecTrustResultProceed:
	break;
    default:
	ret = HX509_ISSUER_NOT_FOUND;
	hx509_set_error_string(context, 0, ret, "Failed to validate trust");
	CFRelease(trust);

#ifndef APPLE_TARGET_EMBEDDED
	{
	    static dispatch_once_t setup;
	    static bool allow_hx509_validation = false;
	    dispatch_once(&setup, ^{
		    CFBooleanRef val;
		    val = CFPreferencesCopyValue(CFSTR("AllowHX509Validation"),
						 CFSTR("org.h5l.hx509"),
						 kCFPreferencesCurrentUser,
						 kCFPreferencesAnyHost);
		    if (val && CFBooleanGetTypeID() == CFGetTypeID(val))
			allow_hx509_validation = CFBooleanGetValue(val);
		    if (val)
			CFRelease(val);
		});
	    if (allow_hx509_validation)
		ret = _hx509_verify_path_internal(context, ctx, cert, pool, validate);
	}
#endif
	return ret;
    }

    if (validate) {
	CFIndex count, n;

	count = SecTrustGetCertificateCount(trust);

	*validate = _hx509_evaluate_alloc();
	if (*validate == NULL) {
	    CFRelease(trust);
	    return ENOMEM;
	}

	for (n = 0; n < count; n++) {
	    SecCertificateRef tc = SecTrustGetCertificateAtIndex(trust, n);
	    heim_assert(tc != NULL, "SecTrustGetCertificateAtIndex didn't return a cert");

	    CFDataRef data = SecCertificateCopyData(tc);
	    heim_assert(data != NULL, "cert w/o data ?");

	    hx509_cert tcert = NULL;

	    ret = hx509_cert_init_data(context, CFDataGetBytePtr(data), CFDataGetLength(data), &tcert);
	    CFRelease(data);
	    if (ret) {
		CFRelease(trust);
		hx509_evaluate_free(*validate);
		*validate = NULL;
		return ret;
	    }
	    heim_array_append_value((*validate)->path, tcert);
	    hx509_cert_free(tcert);
	}
    }

    CFRelease(trust);

    return 0;
#else /* __APPLE__ */
    if (validate)
	*validate = NULL;

    return _hx509_verify_path_internal(context, ctx, cert, pool, validate);
#endif
}


/**
 * Verify a signature made using the private key of an certificate.
 *
 * @param context A hx509 context.
 * @param signer the certificate that made the signature.
 * @param alg algorthm that was used to sign the data.
 * @param data the data that was signed.
 * @param sig the sigature to verify.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_crypto
 */

int
hx509_verify_signature(hx509_context context,
		       const hx509_cert signer,
		       const AlgorithmIdentifier *alg,
		       const heim_octet_string *data,
		       const heim_octet_string *sig)
{
    return _hx509_verify_signature(context, signer, alg, data, sig);
}

int
_hx509_verify_signature_bitstring(hx509_context context,
				  const hx509_cert signer,
				  const AlgorithmIdentifier *alg,
				  const heim_octet_string *data,
				  const heim_bit_string *sig)
{
    heim_octet_string os;

    if (sig->length & 7) {
	hx509_set_error_string(context, 0, HX509_CRYPTO_SIG_INVALID_FORMAT,
			       "signature not multiple of 8 bits");
	return HX509_CRYPTO_SIG_INVALID_FORMAT;
    }

    os.data = sig->data;
    os.length = sig->length / 8;

    return _hx509_verify_signature(context, signer, alg, data, &os);
}



/**
 * Verify that the certificate is allowed to be used for the hostname
 * and address.
 *
 * @param context A hx509 context.
 * @param cert the certificate to match with
 * @param flags Flags to modify the behavior:
 * - HX509_VHN_F_ALLOW_NO_MATCH no match is ok
 * @param type type of hostname:
 * - HX509_HN_HOSTNAME for plain hostname.
 * - HX509_HN_DNSSRV for DNS SRV names.
 * @param hostname the hostname to check
 * @param sa address of the host
 * @param sa_size length of address
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_verify_hostname(hx509_context context,
		      const hx509_cert cert,
		      int flags,
		      hx509_hostname_type type,
		      const char *hostname,
		      const struct sockaddr *sa,
		      /* XXX krb5_socklen_t */ int sa_size)
{
    GeneralNames san;
    const Name *name;
    int ret;
    size_t i, j, k;

    if (sa && sa_size <= 0)
	return EINVAL;

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

    i = 0;
    do {
	ret = find_extension_subject_alt_name(cert->data, &i, &san);
	if (ret == HX509_EXTENSION_NOT_FOUND)
	    break;
	else if (ret != 0)
	    return HX509_PARSING_NAME_FAILED;

	for (j = 0; j < san.len; j++) {
	    switch (san.val[j].element) {
	    case choice_GeneralName_dNSName: {
		heim_printable_string hn;
		hn.data = rk_UNCONST(hostname);
		hn.length = strlen(hostname);

		if (der_printable_string_cmp(&san.val[j].u.dNSName, &hn) == 0) {
		    free_GeneralNames(&san);
		    return 0;
		}
		break;
	    }
	    case choice_GeneralName_directoryName:
	    case choice_GeneralName_otherName:
	    case choice_GeneralName_rfc822Name:
	    case choice_GeneralName_uniformResourceIdentifier:
	    case choice_GeneralName_iPAddress:
	    case choice_GeneralName_registeredID:
	    case invalid_choice_GeneralName:
		break;
	    }
	}
	free_GeneralNames(&san);
    } while (1);

    name = &cert->data->tbsCertificate.subject;

    /* Find first CN= in the name, and try to match the hostname on that */
    for (ret = 0, k = name->u.rdnSequence.len; ret == 0 && k > 0; k--) {
	i = k - 1;
	for (j = 0; ret == 0 && j < name->u.rdnSequence.val[i].len; j++) {
	    AttributeTypeAndValue *n = &name->u.rdnSequence.val[i].val[j];

	    if (der_heim_oid_cmp(&n->type, &asn1_oid_id_at_commonName) == 0) {
		DirectoryString *ds = &n->value;
		switch (ds->element) {
		case choice_DirectoryString_printableString: {
		    heim_printable_string hn;
		    hn.data = rk_UNCONST(hostname);
		    hn.length = strlen(hostname);

		    if (der_printable_string_cmp(&ds->u.printableString, &hn) == 0)
			return 0;
		    break;
		}
		case choice_DirectoryString_ia5String: {
		    heim_ia5_string hn;
		    hn.data = rk_UNCONST(hostname);
		    hn.length = strlen(hostname);

		    if (der_ia5_string_cmp(&ds->u.ia5String, &hn) == 0)
			return 0;
		    break;
		}
		case choice_DirectoryString_utf8String:
		    if (strcasecmp(ds->u.utf8String, hostname) == 0)
			return 0;
		case choice_DirectoryString_teletexString:
		case choice_DirectoryString_bmpString:
		case choice_DirectoryString_universalString:
		case invalid_choice_DirectoryString:
		    break;
		}
		ret = HX509_NAME_CONSTRAINT_ERROR;
	    }
	}
    }

    if ((flags & HX509_VHN_F_ALLOW_NO_MATCH) == 0)
	ret = HX509_NAME_CONSTRAINT_ERROR;

    return ret;
}

int
_hx509_set_cert_attribute(hx509_context context,
			  hx509_cert cert,
			  const heim_oid *oid,
			  const heim_octet_string *attr)
{
    hx509_cert_attribute a;
    void *d;

    if (hx509_cert_get_attribute(cert, oid) != NULL)
	return 0;

    d = realloc(cert->attrs.val,
		sizeof(cert->attrs.val[0]) * (cert->attrs.len + 1));
    if (d == NULL) {
	hx509_clear_error_string(context);
	return ENOMEM;
    }
    cert->attrs.val = d;

    a = malloc(sizeof(*a));
    if (a == NULL)
	return ENOMEM;

    der_copy_octet_string(attr, &a->data);
    der_copy_oid(oid, &a->oid);

    cert->attrs.val[cert->attrs.len] = a;
    cert->attrs.len++;

    return 0;
}

/**
 * Get an external attribute for the certificate, examples are
 * friendly name and id.
 *
 * @param cert hx509 certificate object to search
 * @param oid an oid to search for.
 *
 * @return an hx509_cert_attribute, only valid as long as the
 * certificate is referenced.
 *
 * @ingroup hx509_cert
 */

hx509_cert_attribute
hx509_cert_get_attribute(hx509_cert cert, const heim_oid *oid)
{
    size_t i;
    for (i = 0; i < cert->attrs.len; i++)
	if (der_heim_oid_cmp(oid, &cert->attrs.val[i]->oid) == 0)
	    return cert->attrs.val[i];
    return NULL;
}

/**
 * Set the friendly name on the certificate.
 *
 * @param cert The certificate to set the friendly name on
 * @param name Friendly name.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_set_friendly_name(hx509_cert cert, const char *name)
{
    if (cert->friendlyname)
	free(cert->friendlyname);
    cert->friendlyname = strdup(name);
    if (cert->friendlyname == NULL)
	return ENOMEM;
    return 0;
}

/**
 * Get friendly name of the certificate.
 *
 * @param cert cert to get the friendly name from.
 *
 * @return an friendly name or NULL if there is. The friendly name is
 * only valid as long as the certificate is referenced.
 *
 * @ingroup hx509_cert
 */

const char *
hx509_cert_get_friendly_name(hx509_cert cert)
{
    hx509_cert_attribute a;
    PKCS9_friendlyName n;
    size_t sz;
    int ret;
    size_t i;

    if (cert->friendlyname)
	return cert->friendlyname;

    a = hx509_cert_get_attribute(cert, &asn1_oid_id_pkcs_9_at_friendlyName);
    if (a == NULL) {
	hx509_name name;

	ret = hx509_cert_get_subject(cert, &name);
	if (ret)
	    return NULL;
	ret = hx509_name_to_string(name, &cert->friendlyname);
	hx509_name_free(&name);
	if (ret)
	    return NULL;
	return cert->friendlyname;
    }

    ret = decode_PKCS9_friendlyName(a->data.data, a->data.length, &n, &sz);
    if (ret)
	return NULL;

    if (n.len != 1) {
	free_PKCS9_friendlyName(&n);
	return NULL;
    }

    cert->friendlyname = malloc(n.val[0].length + 1);
    if (cert->friendlyname == NULL) {
	free_PKCS9_friendlyName(&n);
	return NULL;
    }

    for (i = 0; i < n.val[0].length; i++) {
	if (n.val[0].data[i] <= 0xff)
	    cert->friendlyname[i] = n.val[0].data[i] & 0xff;
	else
	    cert->friendlyname[i] = 'X';
    }
    cert->friendlyname[i] = '\0';
    free_PKCS9_friendlyName(&n);

    return cert->friendlyname;
}

int
hx509_cert_set_persistent(hx509_cert cert, heim_octet_string *persistent)
{
    der_free_octet_string(&cert->persistent);
    return der_copy_octet_string(persistent, &cert->persistent);
}

int
hx509_cert_get_persistent(hx509_cert cert, heim_octet_string *persistent)
{
    heim_octet_string os;
    Certificate *c;
    int ret;

    if (cert->persistent.length)
	return der_copy_octet_string(&cert->persistent, persistent);

    c = _hx509_get_cert(cert);

    os.data = c->tbsCertificate.subjectPublicKeyInfo.subjectPublicKey.data;
    os.length =
	c->tbsCertificate.subjectPublicKeyInfo.subjectPublicKey.length / 8;

    ret = _hx509_create_signature(NULL,
				  NULL,
				  hx509_signature_sha1(),
				  &os,
				  NULL,
				  persistent);
    if (ret)
	return ret;

    hx509_cert_set_persistent(cert, persistent);

    return 0;
}

void
_hx509_query_clear(hx509_query *q)
{
    memset(q, 0, sizeof(*q));
}

/**
 * Allocate an query controller. Free using hx509_query_free().
 *
 * @param context A hx509 context.
 * @param q return pointer to a hx509_query.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_query_alloc(hx509_context context, hx509_query **q)
{
    *q = calloc(1, sizeof(**q));
    if (*q == NULL)
	return ENOMEM;
    return 0;
}


/**
 * Set match options for the hx509 query controller.
 *
 * @param q query controller.
 * @param option options to control the query controller.
 *
 * @ingroup hx509_cert
 */

void
hx509_query_match_option(hx509_query *q, hx509_query_option option)
{
    switch(option) {
    case HX509_QUERY_OPTION_PRIVATE_KEY:
	q->match |= HX509_QUERY_PRIVATE_KEY;
	break;
    case HX509_QUERY_OPTION_KU_ENCIPHERMENT:
	q->match |= HX509_QUERY_KU_ENCIPHERMENT;
	break;
    case HX509_QUERY_OPTION_KU_DIGITALSIGNATURE:
	q->match |= HX509_QUERY_KU_DIGITALSIGNATURE;
	break;
    case HX509_QUERY_OPTION_KU_KEYCERTSIGN:
	q->match |= HX509_QUERY_KU_KEYCERTSIGN;
	break;
    case HX509_QUERY_OPTION_END:
	break;
    }
}

/**
 * Set the issuer and serial number of match in the query
 * controller. The function make copies of the isser and serial number.
 *
 * @param q a hx509 query controller
 * @param issuer issuer to search for
 * @param serialNumber the serialNumber of the issuer.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_query_match_issuer_serial(hx509_query *q,
				const Name *issuer,
				const heim_integer *serialNumber)
{
    int ret;
    if (q->serial) {
	der_free_heim_integer(q->serial);
	free(q->serial);
    }
    q->serial = malloc(sizeof(*q->serial));
    if (q->serial == NULL)
	return ENOMEM;
    ret = der_copy_heim_integer(serialNumber, q->serial);
    if (ret) {
	free(q->serial);
	q->serial = NULL;
	return ret;
    }
    if (q->issuer_name) {
	free_Name(q->issuer_name);
	free(q->issuer_name);
    }
    q->issuer_name = malloc(sizeof(*q->issuer_name));
    if (q->issuer_name == NULL)
	return ENOMEM;
    ret = copy_Name(issuer, q->issuer_name);
    if (ret) {
	free(q->issuer_name);
	q->issuer_name = NULL;
	return ret;
    }
    q->match |= HX509_QUERY_MATCH_SERIALNUMBER|HX509_QUERY_MATCH_ISSUER_NAME;
    return 0;
}

/**
 * Set the query controller to match on a friendly name
 *
 * @param q a hx509 query controller.
 * @param name a friendly name to match on
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_query_match_friendly_name(hx509_query *q, const char *name)
{
    if (q->friendlyname)
	free(q->friendlyname);
    q->friendlyname = strdup(name);
    if (q->friendlyname == NULL)
	return ENOMEM;
    q->match |= HX509_QUERY_MATCH_FRIENDLY_NAME;
    return 0;
}

/**
 * Set the query controller to require an one specific EKU (extended
 * key usage). Any previous EKU matching is overwitten. If NULL is
 * passed in as the eku, the EKU requirement is reset.
 *
 * @param q a hx509 query controller.
 * @param eku an EKU to match on.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_query_match_eku(hx509_query *q, const heim_oid *eku)
{
    int ret;

    if (eku == NULL) {
	if (q->eku) {
	    der_free_oid(q->eku);
	    free(q->eku);
	    q->eku = NULL;
	}
	q->match &= ~HX509_QUERY_MATCH_EKU;
    } else {
	if (q->eku) {
	    der_free_oid(q->eku);
	} else {
	    q->eku = calloc(1, sizeof(*q->eku));
	    if (q->eku == NULL)
		return ENOMEM;
	}
	ret = der_copy_oid(eku, q->eku);
	if (ret) {
	    free(q->eku);
	    q->eku = NULL;
	    return ret;
	}
	q->match |= HX509_QUERY_MATCH_EKU;
    }
    return 0;
}

#ifdef HEIM_HX_EXPR
int
hx509_query_match_expr(hx509_context context, hx509_query *q, const char *expr)
{
    if (q->expr) {
	_hx509_expr_free(q->expr);
	q->expr = NULL;
    }

    if (expr == NULL) {
	q->match &= ~HX509_QUERY_MATCH_EXPR;
    } else {
	q->expr = _hx509_expr_parse(expr);
	if (q->expr)
	    q->match |= HX509_QUERY_MATCH_EXPR;
    }

    return 0;
}
#endif

/**
 * Set the query controller to match using a specific match function.
 *
 * @param q a hx509 query controller.
 * @param func function to use for matching, if the argument is NULL,
 * the match function is removed.
 * @param ctx context passed to the function.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_query_match_cmp_func(hx509_query *q,
			   int (*func)(hx509_context, hx509_cert, void *),
			   void *ctx)
{
    if (func)
	q->match |= HX509_QUERY_MATCH_FUNCTION;
    else
	q->match &= ~HX509_QUERY_MATCH_FUNCTION;
    q->cmp_func = func;
    q->cmp_func_ctx = ctx;
    return 0;
}

/**
 *
 */

int
hx509_query_match_persistent(hx509_query *q, heim_octet_string *ident)
{
    if (ident)
	q->match |= HX509_QUERY_MATCH_PERSISTENT;
    else
	q->match &= ~HX509_QUERY_MATCH_PERSISTENT;
    q->persistent = ident;
    return 0;
}

/**
 * Free the query controller.
 *
 * @param context A hx509 context.
 * @param q a pointer to the query controller.
 *
 * @ingroup hx509_cert
 */

void
hx509_query_free(hx509_context context, hx509_query *q)
{
    if (q == NULL)
	return;

    if (q->serial) {
	der_free_heim_integer(q->serial);
	free(q->serial);
    }
    if (q->issuer_name) {
	free_Name(q->issuer_name);
	free(q->issuer_name);
    }
    if (q->eku) {
	der_free_oid(q->eku);
	free(q->eku);
    }
    if (q->friendlyname)
	free(q->friendlyname);
#ifdef HEIM_HX_EXPR
    if (q->expr)
	_hx509_expr_free(q->expr);
#endif

    memset(q, 0, sizeof(*q));
    free(q);
}

int
_hx509_query_match_cert(hx509_context context, const hx509_query *q, hx509_cert cert)
{
    Certificate *c = _hx509_get_cert(cert);
    int ret, diff;

    if ((q->match & HX509_QUERY_FIND_ISSUER_CERT) &&
	_hx509_cert_is_parent_cmp(q->subject, c, 0) != 0)
	return 0;

    if ((q->match & HX509_QUERY_MATCH_CERTIFICATE) &&
	_hx509_Certificate_cmp(q->certificate, c) != 0)
	return 0;

    if ((q->match & HX509_QUERY_MATCH_SERIALNUMBER)
	&& der_heim_integer_cmp(&c->tbsCertificate.serialNumber, q->serial) != 0)
	return 0;

    if (q->match & HX509_QUERY_MATCH_ISSUER_NAME) {
	ret = _hx509_name_cmp(&c->tbsCertificate.issuer, q->issuer_name, &diff);
	if (ret || diff)
	    return 0;
    }

    if (q->match & HX509_QUERY_MATCH_SUBJECT_NAME) {
	ret = _hx509_name_cmp(&c->tbsCertificate.subject, q->subject_name, &diff);
	if (ret || diff)
	    return 0;
    }

    if (q->match & HX509_QUERY_MATCH_SUBJECT_KEY_ID) {
	SubjectKeyIdentifier si;

	ret = _hx509_find_extension_subject_key_id(c, &si);
	if (ret == 0) {
	    if (der_heim_octet_string_cmp(&si, q->subject_id) != 0)
		ret = 1;
	    free_SubjectKeyIdentifier(&si);
	}
	if (ret)
	    return 0;
    }
    if ((q->match & HX509_QUERY_MATCH_ISSUER_ID))
	return 0;
    if ((q->match & HX509_QUERY_PRIVATE_KEY) &&
	_hx509_cert_private_key(cert) == NULL)
	return 0;

    {
	unsigned ku = 0;
	if (q->match & HX509_QUERY_KU_DIGITALSIGNATURE)
	    ku |= (1 << 0);
	if (q->match & HX509_QUERY_KU_NONREPUDIATION)
	    ku |= (1 << 1);
	if (q->match & HX509_QUERY_KU_ENCIPHERMENT)
	    ku |= (1 << 2);
	if (q->match & HX509_QUERY_KU_DATAENCIPHERMENT)
	    ku |= (1 << 3);
	if (q->match & HX509_QUERY_KU_KEYAGREEMENT)
	    ku |= (1 << 4);
	if (q->match & HX509_QUERY_KU_KEYCERTSIGN)
	    ku |= (1 << 5);
	if (q->match & HX509_QUERY_KU_CRLSIGN)
	    ku |= (1 << 6);
	if (ku && check_key_usage(context, c, ku, TRUE))
	    return 0;
    }
    if ((q->match & HX509_QUERY_ANCHOR))
	return 0;

    if (q->match & HX509_QUERY_MATCH_LOCAL_KEY_ID) {
	hx509_cert_attribute a;

	a = hx509_cert_get_attribute(cert, &asn1_oid_id_pkcs_9_at_localKeyId);
	if (a == NULL)
	    return 0;
	if (der_heim_octet_string_cmp(&a->data, q->local_key_id) != 0)
	    return 0;
    }

    if (q->match & HX509_QUERY_NO_MATCH_PATH) {
	size_t i;

	for (i = 0; i < q->path->len; i++)
	    if (hx509_cert_cmp(q->path->val[i], cert) == 0)
		return 0;
    }
    if (q->match & HX509_QUERY_MATCH_FRIENDLY_NAME) {
	const char *name = hx509_cert_get_friendly_name(cert);
	if (name == NULL)
	    return 0;
	if (strcasecmp(q->friendlyname, name) != 0)
	    return 0;
    }
    if (q->match & HX509_QUERY_MATCH_FUNCTION) {
	ret = (*q->cmp_func)(context, cert, q->cmp_func_ctx);
	if (ret != 0)
	    return 0;
    }

    if (q->match & HX509_QUERY_MATCH_KEY_HASH_SHA1) {
	heim_octet_string os;

	os.data = c->tbsCertificate.subjectPublicKeyInfo.subjectPublicKey.data;
	os.length =
	    c->tbsCertificate.subjectPublicKeyInfo.subjectPublicKey.length / 8;

	ret = _hx509_verify_signature(context,
				      NULL,
				      hx509_signature_sha1(),
				      &os,
				      q->keyhash_sha1);
	if (ret != 0)
	    return 0;
    }

    if (q->match & HX509_QUERY_MATCH_TIME) {
	time_t t;
	t = _hx509_Time2time_t(&c->tbsCertificate.validity.notBefore);
	if (t > q->timenow)
	    return 0;
	t = _hx509_Time2time_t(&c->tbsCertificate.validity.notAfter);
	if (t < q->timenow)
	    return 0;
    }

    /* If an EKU is required, check the cert for it. */
    if ((q->match & HX509_QUERY_MATCH_EKU) &&
	hx509_cert_check_eku(context, cert, q->eku, 0))
	return 0;

    if ((q->match & HX509_QUERY_MATCH_EXPR)) {
#ifdef HEIM_HX_EXPR
	hx509_env env = NULL;

	ret = _hx509_cert_to_env(context, cert, &env);
	if (ret)
	    return 0;

	ret = _hx509_expr_eval(context, env, q->expr);
	hx509_env_free(&env);
	if (ret == 0)
	    return 0;
#else
	return 0;
#endif
    }
    if ((q->match & HX509_QUERY_MATCH_PERSISTENT)) {
	heim_octet_string p;

	ret = hx509_cert_get_persistent(cert, &p);
	if (ret)
	    return 0;

	ret = der_heim_octet_string_cmp(&p, q->persistent);
	der_free_octet_string(&p);
	if (ret != 0)
	    return 0;
    }

    if (q->match & ~HX509_QUERY_MASK)
	return 0;

    return 1;
}

/**
 * Check the extended key usage on the hx509 certificate.
 *
 * @param context A hx509 context.
 * @param cert A hx509 context.
 * @param eku the EKU to check for
 * @param allow_any_eku if the any EKU is set, allow that to be a
 * substitute.
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_check_eku(hx509_context context, hx509_cert cert,
		     const heim_oid *eku, int allow_any_eku)
{
    ExtKeyUsage e;
    int ret;
    size_t i;

    ret = find_extension_eku(_hx509_get_cert(cert), &e);
    if (ret) {
	hx509_clear_error_string(context);
	return ret;
    }

    for (i = 0; i < e.len; i++) {
	if (der_heim_oid_cmp(eku, &e.val[i]) == 0) {
	    free_ExtKeyUsage(&e);
	    return 0;
	}
	if (allow_any_eku) {
#if 0
	    if (der_heim_oid_cmp(id_any_eku, &e.val[i]) == 0) {
		free_ExtKeyUsage(&e);
		return 0;
	    }
#endif
	}
    }
    free_ExtKeyUsage(&e);
    hx509_clear_error_string(context);
    return HX509_CERTIFICATE_MISSING_EKU;
}

int
_hx509_cert_get_keyusage(hx509_context context,
			 hx509_cert c,
			 KeyUsage *ku)
{
    Certificate *cert;
    const Extension *e;
    size_t size;
    int ret;
    size_t i = 0;

    memset(ku, 0, sizeof(*ku));

    cert = _hx509_get_cert(c);

    if (_hx509_cert_get_version(cert) < 3)
	return 0;

    e = find_extension(cert, &asn1_oid_id_x509_ce_keyUsage, &i);
    if (e == NULL)
	return HX509_KU_CERT_MISSING;

    ret = decode_KeyUsage(e->extnValue.data, e->extnValue.length, ku, &size);
    if (ret)
	return ret;
    return 0;
}

int
_hx509_cert_get_eku(hx509_context context,
		    hx509_cert cert,
		    ExtKeyUsage *e)
{
    int ret;

    memset(e, 0, sizeof(*e));

    ret = find_extension_eku(_hx509_get_cert(cert), e);
    if (ret && ret != HX509_EXTENSION_NOT_FOUND) {
	hx509_clear_error_string(context);
	return ret;
    }
    return 0;
}

/**
 * Encodes the hx509 certificate as a DER encode binary.
 *
 * @param context A hx509 context.
 * @param c the certificate to encode.
 * @param os the encode certificate, set to NULL, 0 on case of
 * error. Free the os->data with hx509_xfree().
 *
 * @return An hx509 error code, see hx509_get_error_string().
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_binary(hx509_context context, hx509_cert c, heim_octet_string *os)
{
    size_t size = 0;
    int ret;

    os->data = NULL;
    os->length = 0;

    ASN1_MALLOC_ENCODE(Certificate, os->data, os->length,
		       _hx509_get_cert(c), &size, ret);
    if (ret) {
	os->data = NULL;
	os->length = 0;
	return ret;
    }
    if (os->length != size)
	_hx509_abort("internal ASN.1 encoder error");

    return ret;
}

/*
 * Last to avoid lost __attribute__s due to #undef.
 */

#undef __attribute__
#define __attribute__(X)

void
_hx509_abort(const char *fmt, ...)
    HEIMDAL_NORETURN_ATTRIBUTE
    HEIMDAL_PRINTF_ATTRIBUTE((printf, 1, 2))
{
    va_list ap;
    va_start(ap, fmt);
    heim_abortv(fmt, ap);
    va_end(ap);
}

/**
 * Free a data element allocated in the library.
 *
 * @param ptr data to be freed.
 *
 * @ingroup hx509_misc
 */

void
hx509_xfree(void *ptr)
{
    free(ptr);
}

/**
 *
 */

int
_hx509_cert_to_env(hx509_context context, hx509_cert cert, hx509_env *env)
{
    ExtKeyUsage eku;
    hx509_name name;
    char *buf;
    int ret;
    hx509_env envcert = NULL;

    *env = NULL;

    /* version */
    asprintf(&buf, "%d", _hx509_cert_get_version(_hx509_get_cert(cert)));
    ret = hx509_env_add(context, &envcert, "version", buf);
    free(buf);
    if (ret)
	goto out;

    /* subject */
    ret = hx509_cert_get_subject(cert, &name);
    if (ret)
	goto out;

    ret = hx509_name_to_string(name, &buf);
    if (ret) {
	hx509_name_free(&name);
	goto out;
    }

    ret = hx509_env_add(context, &envcert, "subject", buf);
    hx509_name_free(&name);
    if (ret)
	goto out;

    /* issuer */
    ret = hx509_cert_get_issuer(cert, &name);
    if (ret)
	goto out;

    ret = hx509_name_to_string(name, &buf);
    hx509_name_free(&name);
    if (ret)
	goto out;

    ret = hx509_env_add(context, &envcert, "issuer", buf);
    hx509_xfree(buf);
    if (ret)
	goto out;

    /* eku */

    ret = _hx509_cert_get_eku(context, cert, &eku);
    if (ret == HX509_EXTENSION_NOT_FOUND)
	;
    else if (ret != 0)
	goto out;
    else {
	size_t i;
	hx509_env enveku = NULL;

	for (i = 0; i < eku.len; i++) {

	    ret = der_print_heim_oid(&eku.val[i], '.', &buf);
	    if (ret) {
		free_ExtKeyUsage(&eku);
		hx509_env_free(&enveku);
		goto out;
	    }
	    ret = hx509_env_add(context, &enveku, buf, "oid-name-here");
	    free(buf);
	    if (ret) {
		free_ExtKeyUsage(&eku);
		hx509_env_free(&enveku);
		goto out;
	    }
	}
	free_ExtKeyUsage(&eku);

	ret = hx509_env_add_binding(context, &envcert, "eku", enveku);
	if (ret) {
	    hx509_env_free(&enveku);
	    goto out;
	}
    }

    {
	Certificate *c = _hx509_get_cert(cert);
        heim_octet_string os, sig;
	hx509_env envhash = NULL;

	os.data = c->tbsCertificate.subjectPublicKeyInfo.subjectPublicKey.data;
	os.length =
	  c->tbsCertificate.subjectPublicKeyInfo.subjectPublicKey.length / 8;

	ret = _hx509_create_signature(context,
				      NULL,
				      hx509_signature_sha1(),
				      &os,
				      NULL,
				      &sig);
	if (ret != 0)
	    goto out;

	ret = (int)hex_encode(sig.data, sig.length, &buf);
	der_free_octet_string(&sig);
	if (ret < 0) {
	    ret = ENOMEM;
	    hx509_set_error_string(context, 0, ret,
				   "Out of memory");
	    goto out;
	}

	ret = hx509_env_add(context, &envhash, "sha1", buf);
	free(buf);
	if (ret)
	    goto out;

	ret = hx509_env_add_binding(context, &envcert, "hash", envhash);
	if (ret) {
	  hx509_env_free(&envhash);
	  goto out;
	}
    }

    ret = hx509_env_add_binding(context, env, "certificate", envcert);
    if (ret)
	goto out;

    return 0;

out:
    hx509_env_free(&envcert);
    return ret;
}

/**
 * Print a simple representation of a certificate
 *
 * @param context A hx509 context, can be NULL
 * @param cert certificate to print
 * @param out the stdio output stream, if NULL, stdout is used
 *
 * @return An hx509 error code
 *
 * @ingroup hx509_cert
 */

int
hx509_print_cert(hx509_context context, hx509_cert cert, FILE *out)
{
    hx509_name name;
    char *str;
    int ret;

    if (out == NULL)
	out = stderr;

    ret = hx509_cert_get_issuer(cert, &name);
    if (ret)
	return ret;
    hx509_name_to_string(name, &str);
    hx509_name_free(&name);
    fprintf(out, "    issuer:  \"%s\"\n", str);
    free(str);

    ret = hx509_cert_get_subject(cert, &name);
    if (ret)
	return ret;
    hx509_name_to_string(name, &str);
    hx509_name_free(&name);
    fprintf(out, "    subject: \"%s\"\n", str);
    free(str);

    {
	heim_integer serialNumber;

	ret = hx509_cert_get_serialnumber(cert, &serialNumber);
	if (ret)
	    return ret;
	ret = der_print_hex_heim_integer(&serialNumber, &str);
	if (ret)
	    return ret;
	der_free_heim_integer(&serialNumber);
	fprintf(out, "    serial: %s\n", str);
	free(str);
    }

    fprintf(out, "    keyusage: ");
    ret = hx509_cert_keyusage_print(context, cert, &str);
    if (ret == 0) {
	fprintf(out, "%s\n", str);
	free(str);
    } else
	fprintf(out, "no\n");

    {
	heim_octet_string os;

	fprintf(out, "    persistent: ");
	ret = hx509_cert_get_persistent(cert, &os);
	if (ret == 0) {
	    ret = (int)hex_encode(os.data, os.length, &str);
	    if (ret > 0) {
		fprintf(out, "%s\n", str);
		free(str);
	    } else {
		fprintf(out, "out of memory\n");
	    }
	    der_free_octet_string(&os);
	} else {
	    fprintf(out, "no\n");
	}
    }

    return 0;
}

/**
 * Get a fast an loose version of the apple id, can't be used for acl checking
 *
 * @ingroup hx509_cert
 */

int
hx509_cert_get_appleid(hx509_context context, hx509_cert cert, char **appleid)
{
    unsigned oids[] = { 1, 2, 840, 113635, 100, 3, 2, 1 };
    const heim_oid mobileMe = { sizeof(oids)/sizeof(oids[0]), oids };
    unsigned count = 0;
    hx509_name name;
    char *str;
    int ret;

    *appleid = NULL;

    ret = hx509_cert_check_eku(context, cert, &mobileMe, 0);
    if (ret)
	return ret;

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

    ret = hx509_name_get_component(name, 3, &asn1_oid_id_at_commonName, &count, &str);
    hx509_name_free(&name);
    if (ret)
	return ret;

    asprintf(appleid, "%s@me.com", str);
    free(str);
    if (*appleid == NULL)
	return ENOMEM;

    return 0;
}