/* pcy_tree.c */

/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL

 * project 2004.

 */

/* ====================================================================

 * Copyright (c) 2004 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer. 

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#include "cryptlib.h"

#include <openssl/x509.h>

#include <openssl/x509v3.h>

#include "pcy_int.h"

/* Initialize policy tree. Return values:

 *  0 Some internal error occured.

 * -1 Inconsistent or invalid extensions in certificates.

 *  1 Tree initialized OK.

 *  2 Policy tree is empty.

 *  5 Tree OK and requireExplicitPolicy true.

 *  6 Tree empty and requireExplicitPolicy true.

 */

static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,

			unsigned int flags)

	{

	X509_POLICY_TREE *tree;

	X509_POLICY_LEVEL *level;

	const X509_POLICY_CACHE *cache;

	X509_POLICY_DATA *data = NULL;

	X509 *x;

	int ret = 1;

	int i, n;

	int explicit_policy;

	int any_skip;

	int map_skip;

	*ptree = NULL;

	n = sk_X509_num(certs);

	/* Disable policy mapping for now... */

	flags |= X509_V_FLAG_INHIBIT_MAP;

	if (flags & X509_V_FLAG_EXPLICIT_POLICY)

		explicit_policy = 0;

	else

		explicit_policy = n + 1;

	if (flags & X509_V_FLAG_INHIBIT_ANY)

		any_skip = 0;

	else

		any_skip = n + 1;

	if (flags & X509_V_FLAG_INHIBIT_MAP)

		map_skip = 0;

	else

		map_skip = n + 1;

	/* Can't do anything with just a trust anchor */

	if (n == 1)

		return 1;

	/* First setup policy cache in all certificates apart from the

	 * trust anchor. Note any bad cache results on the way. Also can

	 * calculate explicit_policy value at this point.

	 */

	for (i = n - 2; i >= 0; i--)

		{

		x = sk_X509_value(certs, i);

		X509_check_purpose(x, -1, -1);

		cache = policy_cache_set(x);

		/* If cache NULL something bad happened: return immediately */

		if (cache == NULL)

			return 0;

		/* If inconsistent extensions keep a note of it but continue */

		if (x->ex_flags & EXFLAG_INVALID_POLICY)

			ret = -1;

		/* Otherwise if we have no data (hence no CertificatePolicies)

		 * and haven't already set an inconsistent code note it.

		 */

		else if ((ret == 1) && !cache->data)

			ret = 2;

		if (explicit_policy > 0)

			{

			explicit_policy--;

			if (!(x->ex_flags & EXFLAG_SS)

				&& (cache->explicit_skip != -1)

				&& (cache->explicit_skip < explicit_policy))

				explicit_policy = cache->explicit_skip;

			}

		}

	if (ret != 1)

		{

		if (ret == 2 && !explicit_policy)

			return 6;

		return ret;

		}

	/* If we get this far initialize the tree */

	tree = OPENSSL_malloc(sizeof(X509_POLICY_TREE));

	if (!tree)

		return 0;

	tree->flags = 0;

	tree->levels = OPENSSL_malloc(sizeof(X509_POLICY_LEVEL) * n);

#ifdef SYMBIAN	

	if (!tree->levels)

		return 0;

#endif

	tree->nlevel = 0;

	tree->extra_data = NULL;

	tree->auth_policies = NULL;

	tree->user_policies = NULL;

	if (!tree)

		{

		OPENSSL_free(tree);

		return 0;

		}

	memset(tree->levels, 0, n * sizeof(X509_POLICY_LEVEL));

	tree->nlevel = n;

	level = tree->levels;

	/* Root data: initialize to anyPolicy */

	data = policy_data_new(NULL, OBJ_nid2obj(NID_any_policy), 0);

	if (!data || !level_add_node(level, data, NULL, tree))

		goto bad_tree;

	for (i = n - 2; i >= 0; i--)

		{

		level++;

		x = sk_X509_value(certs, i);

		cache = policy_cache_set(x);

		CRYPTO_add(&x->references, 1, CRYPTO_LOCK_X509);

		level->cert = x;

		if (!cache->anyPolicy)

				level->flags |= X509_V_FLAG_INHIBIT_ANY;

		/* Determine inhibit any and inhibit map flags */

		if (any_skip == 0)

			{

			/* Any matching allowed if certificate is self

			 * issued and not the last in the chain.

			 */

			if (!(x->ex_flags & EXFLAG_SS) || (i == 0))

				level->flags |= X509_V_FLAG_INHIBIT_ANY;

			}

		else

			{

			any_skip--;

			if ((cache->any_skip > 0)

				&& (cache->any_skip < any_skip))

				any_skip = cache->any_skip;

			}

		if (map_skip == 0)

			level->flags |= X509_V_FLAG_INHIBIT_MAP;

		else

			{

			map_skip--;

			if ((cache->map_skip > 0)

				&& (cache->map_skip < map_skip))

				map_skip = cache->map_skip;

			}

		}

	*ptree = tree;

	if (explicit_policy)

		return 1;

	else

		return 5;

	bad_tree:

	X509_policy_tree_free(tree);

	return 0;

	}

/* This corresponds to RFC3280 XXXX XXXXX:

 * link any data from CertificatePolicies onto matching parent

 * or anyPolicy if no match.

 */

static int tree_link_nodes(X509_POLICY_LEVEL *curr,

				const X509_POLICY_CACHE *cache)

	{

	int i;

	X509_POLICY_LEVEL *last;

	X509_POLICY_DATA *data;

	X509_POLICY_NODE *parent;

	last = curr - 1;

	for (i = 0; i < sk_X509_POLICY_DATA_num(cache->data); i++)

		{

		data = sk_X509_POLICY_DATA_value(cache->data, i);

		/* If a node is mapped any it doesn't have a corresponding

		 * CertificatePolicies entry. 

		 * However such an identical node would be created

		 * if anyPolicy matching is enabled because there would be

		 * no match with the parent valid_policy_set. So we create

		 * link because then it will have the mapping flags

		 * right and we can prune it later.

		 */

		if ((data->flags & POLICY_DATA_FLAG_MAPPED_ANY)

			&& !(curr->flags & X509_V_FLAG_INHIBIT_ANY))

			continue;

		/* Look for matching node in parent */

		parent = level_find_node(last, data->valid_policy);

		/* If no match link to anyPolicy */

		if (!parent)

			parent = last->anyPolicy;

		if (parent && !level_add_node(curr, data, parent, NULL))

				return 0;

		}

	return 1;

	}

/* This corresponds to RFC3280 XXXX XXXXX:

 * Create new data for any unmatched policies in the parent and link

 * to anyPolicy.

 */

static int tree_link_any(X509_POLICY_LEVEL *curr,

			const X509_POLICY_CACHE *cache,

			X509_POLICY_TREE *tree)

	{

	int i;

	X509_POLICY_DATA *data;

	X509_POLICY_NODE *node;

	X509_POLICY_LEVEL *last;

	last = curr - 1;

	for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++)

		{

		node = sk_X509_POLICY_NODE_value(last->nodes, i);

		/* Skip any node with any children: we only want unmathced

		 * nodes.

		 *

		 * Note: need something better for policy mapping

		 * because each node may have multiple children 

		 */

		if (node->nchild)

			continue;

		/* Create a new node with qualifiers from anyPolicy and

		 * id from unmatched node.

		 */

		data = policy_data_new(NULL, node->data->valid_policy, 

						node_critical(node));

		if (data == NULL)

			return 0;

		data->qualifier_set = curr->anyPolicy->data->qualifier_set;

		data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;

		if (!level_add_node(curr, data, node, tree))

			{

			policy_data_free(data);

			return 0;

			}

		}

	/* Finally add link to anyPolicy */

	if (last->anyPolicy)

		{

		if (!level_add_node(curr, cache->anyPolicy,

						last->anyPolicy, NULL))

			return 0;

		}

	return 1;

	}

/* Prune the tree: delete any child mapped child data on the current level

 * then proceed up the tree deleting any data with no children. If we ever

 * have no data on a level we can halt because the tree will be empty.

 */

static int tree_prune(X509_POLICY_TREE *tree, X509_POLICY_LEVEL *curr)

	{

	X509_POLICY_NODE *node;

	int i;

	for (i = sk_X509_POLICY_NODE_num(curr->nodes) - 1; i >= 0; i--)

		{

		node = sk_X509_POLICY_NODE_value(curr->nodes, i);

		/* Delete any mapped data: see RFC3280 XXXX */

		if (node->data->flags & POLICY_DATA_FLAG_MAP_MASK)

			{

			node->parent->nchild--;

			OPENSSL_free(node);

			(void)sk_X509_POLICY_NODE_delete(curr->nodes, i);

			}

		}

	for(;;)	{

		--curr;

		for (i = sk_X509_POLICY_NODE_num(curr->nodes) - 1; i >= 0; i--)

			{

			node = sk_X509_POLICY_NODE_value(curr->nodes, i);

			if (node->nchild == 0)

				{

				node->parent->nchild--;

				OPENSSL_free(node);

				(void)sk_X509_POLICY_NODE_delete(curr->nodes, i);

				}

			}

		if (curr->anyPolicy && !curr->anyPolicy->nchild)

			{

			if (curr->anyPolicy->parent)

				curr->anyPolicy->parent->nchild--;

			OPENSSL_free(curr->anyPolicy);

			curr->anyPolicy = NULL;

			}

		if (curr == tree->levels)

			{

			/* If we zapped anyPolicy at top then tree is empty */

			if (!curr->anyPolicy)

					return 2;

			return 1;

			}

		}

	return 1;

	}

static int tree_add_auth_node(STACK_OF(X509_POLICY_NODE) **pnodes,

						 X509_POLICY_NODE *pcy)

	{

	if (!*pnodes)

		{

		*pnodes = policy_node_cmp_new();

		if (!*pnodes)

			return 0;

		}

	else if (sk_X509_POLICY_NODE_find(*pnodes, pcy) != -1)

		return 1;

	if (!sk_X509_POLICY_NODE_push(*pnodes, pcy))

		return 0;

	return 1;

	}

/* Calculate the authority set based on policy tree.

 * The 'pnodes' parameter is used as a store for the set of policy nodes

 * used to calculate the user set. If the authority set is not anyPolicy

 * then pnodes will just point to the authority set. If however the authority

 * set is anyPolicy then the set of valid policies (other than anyPolicy)

 * is store in pnodes. The return value of '2' is used in this case to indicate

 * that pnodes should be freed.

 */

static int tree_calculate_authority_set(X509_POLICY_TREE *tree,

					STACK_OF(X509_POLICY_NODE) **pnodes)

	{

	X509_POLICY_LEVEL *curr;

	X509_POLICY_NODE *node, *anyptr;

	STACK_OF(X509_POLICY_NODE) **addnodes;

	int i, j;

	curr = tree->levels + tree->nlevel - 1;

	/* If last level contains anyPolicy set is anyPolicy */

	if (curr->anyPolicy)

		{

		if (!tree_add_auth_node(&tree->auth_policies, curr->anyPolicy))

			return 0;

		addnodes = pnodes;

		}

	else

		/* Add policies to authority set */

		addnodes = &tree->auth_policies;

	curr = tree->levels;

	for (i = 1; i < tree->nlevel; i++)

		{

		/* If no anyPolicy node on this this level it can't

		 * appear on lower levels so end search.

		 */

		if (!(anyptr = curr->anyPolicy))

			break;

		curr++;

		for (j = 0; j < sk_X509_POLICY_NODE_num(curr->nodes); j++)

			{

			node = sk_X509_POLICY_NODE_value(curr->nodes, j);

			if ((node->parent == anyptr)

				&& !tree_add_auth_node(addnodes, node))

					return 0;

			}

		}

	if (addnodes == pnodes)

		return 2;

	*pnodes = tree->auth_policies;

	return 1;

	}

static int tree_calculate_user_set(X509_POLICY_TREE *tree,

				STACK_OF(ASN1_OBJECT) *policy_oids,

				STACK_OF(X509_POLICY_NODE) *auth_nodes)

	{

	int i;

	X509_POLICY_NODE *node;

	ASN1_OBJECT *oid;

	X509_POLICY_NODE *anyPolicy;

	X509_POLICY_DATA *extra;

	/* Check if anyPolicy present in authority constrained policy set:

	 * this will happen if it is a leaf node.

	 */

	if (sk_ASN1_OBJECT_num(policy_oids) <= 0)

		return 1;

	anyPolicy = tree->levels[tree->nlevel - 1].anyPolicy;

	for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++)

		{

		oid = sk_ASN1_OBJECT_value(policy_oids, i);

		if (OBJ_obj2nid(oid) == NID_any_policy)

			{

			tree->flags |= POLICY_FLAG_ANY_POLICY;

			return 1;

			}

		}

	for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++)

		{

		oid = sk_ASN1_OBJECT_value(policy_oids, i);

		node = tree_find_sk(auth_nodes, oid);

		if (!node)

			{

			if (!anyPolicy)

				continue;

			/* Create a new node with policy ID from user set

			 * and qualifiers from anyPolicy.

			 */

			extra = policy_data_new(NULL, oid,

						node_critical(anyPolicy));

			if (!extra)

				return 0;

			extra->qualifier_set = anyPolicy->data->qualifier_set;

			extra->flags = POLICY_DATA_FLAG_SHARED_QUALIFIERS

						| POLICY_DATA_FLAG_EXTRA_NODE;

			node = level_add_node(NULL, extra, anyPolicy->parent,

						tree);

			}

		if (!tree->user_policies)

			{

			tree->user_policies = sk_X509_POLICY_NODE_new_null();

			if (!tree->user_policies)

				return 1;

			}

		if (!sk_X509_POLICY_NODE_push(tree->user_policies, node))

			return 0;

		}

	return 1;

	}

static int tree_evaluate(X509_POLICY_TREE *tree)

	{

	int ret, i;

	X509_POLICY_LEVEL *curr = tree->levels + 1;

	const X509_POLICY_CACHE *cache;

	for(i = 1; i < tree->nlevel; i++, curr++)

		{

		cache = policy_cache_set(curr->cert);

		if (!tree_link_nodes(curr, cache))

			return 0;

		if (!(curr->flags & X509_V_FLAG_INHIBIT_ANY)

			&& !tree_link_any(curr, cache, tree))

			return 0;

		ret = tree_prune(tree, curr);

		if (ret != 1)

			return ret;

		}

	return 1;

	}

static void exnode_free(X509_POLICY_NODE *node)

	{

	if (node->data && (node->data->flags & POLICY_DATA_FLAG_EXTRA_NODE))

		OPENSSL_free(node);

	}

EXPORT_C void X509_policy_tree_free(X509_POLICY_TREE *tree)

	{

	X509_POLICY_LEVEL *curr;

	int i;

	if (!tree)

		return;

	sk_X509_POLICY_NODE_free(tree->auth_policies);

	sk_X509_POLICY_NODE_pop_free(tree->user_policies, exnode_free);

	for(i = 0, curr = tree->levels; i < tree->nlevel; i++, curr++)

		{

		if (curr->cert)

			X509_free(curr->cert);

		if (curr->nodes)

			sk_X509_POLICY_NODE_pop_free(curr->nodes,

						policy_node_free);

		if (curr->anyPolicy)

			policy_node_free(curr->anyPolicy);

		}

	if (tree->extra_data)

		sk_X509_POLICY_DATA_pop_free(tree->extra_data,

						policy_data_free);

	OPENSSL_free(tree->levels);

	OPENSSL_free(tree);

	}

/* Application policy checking function.

 * Return codes:

 *  0 	Internal Error.

 *  1   Successful.

 * -1   One or more certificates contain invalid or inconsistent extensions

 * -2	User constrained policy set empty and requireExplicit true.

 */

EXPORT_C int X509_policy_check(X509_POLICY_TREE **ptree, int *pexplicit_policy,

			STACK_OF(X509) *certs,

			STACK_OF(ASN1_OBJECT) *policy_oids,

			unsigned int flags)

	{

	int ret;

	X509_POLICY_TREE *tree = NULL;

	STACK_OF(X509_POLICY_NODE) *nodes, *auth_nodes = NULL;

	*ptree = NULL;

	*pexplicit_policy = 0;

	ret = tree_init(&tree, certs, flags);

	switch (ret)

		{

		/* Tree empty requireExplicit False: OK */

		case 2:

		return 1;

		/* Some internal error */

		case 0:

		return 0;

		/* Tree empty requireExplicit True: Error */

		case 6:

		*pexplicit_policy = 1;

		return -2;

		/* Tree OK requireExplicit True: OK and continue */

		case 5:

		*pexplicit_policy = 1;

		break;

		/* Tree OK: continue */

		case 1:

		if (!tree)

			/*

			 * tree_init() returns success and a null tree

			 * if it's just looking at a trust anchor.

			 * I'm not sure that returning success here is

			 * correct, but I'm sure that reporting this

			 * as an internal error which our caller

			 * interprets as a malloc failure is wrong.

			 */

			return 1;

		break;

		}

	if (!tree) goto error;

	ret = tree_evaluate(tree);

	if (ret <= 0)

		goto error;

	/* Return value 2 means tree empty */

	if (ret == 2)

		{

		X509_policy_tree_free(tree);

		if (*pexplicit_policy)

			return -2;

		else

			return 1;

		}

	/* Tree is not empty: continue */

	ret = tree_calculate_authority_set(tree, &auth_nodes);

	if (!ret)

		goto error;

	if (!tree_calculate_user_set(tree, policy_oids, auth_nodes))

		goto error;

	if (ret == 2)

		sk_X509_POLICY_NODE_free(auth_nodes);

	if (tree)

		*ptree = tree;

	if (*pexplicit_policy)

		{

		nodes = X509_policy_tree_get0_user_policies(tree);

		if (sk_X509_POLICY_NODE_num(nodes) <= 0)

			return -2;

		}

	return 1;

	error:

	X509_policy_tree_free(tree);

	return 0;

	}