text: /* crypto/x509/x509_vfy.c */
  /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   * 
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   * 
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   * 
   * 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 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 acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from 
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   * 
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
   * 
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.]
   */
  
  #include <stdio.h>
  #include <time.h>
  #include <errno.h>
  
  #include "cryptlib.h"
  #include <openssl/crypto.h>
  #include <openssl/lhash.h>
  #include <openssl/buffer.h>
  #include <openssl/evp.h>
  #include <openssl/asn1.h>
  #include <openssl/x509.h>
  #include <openssl/x509v3.h>
  #include <openssl/objects.h>
  
  static int null_callback(int ok,X509_STORE_CTX *e);
  static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
  static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x);
  static int check_chain_extensions(X509_STORE_CTX *ctx);
  static int check_trust(X509_STORE_CTX *ctx);
  static int check_revocation(X509_STORE_CTX *ctx);
  static int check_cert(X509_STORE_CTX *ctx);
  static int check_policy(X509_STORE_CTX *ctx);
  static int internal_verify(X509_STORE_CTX *ctx);
  const char X509_version[]="X.509" OPENSSL_VERSION_PTEXT;
  
  
  static int null_callback(int ok, X509_STORE_CTX *e)
  	{
  	return ok;
  	}
  
  #if 0
  static int x509_subject_cmp(X509 **a, X509 **b)
  	{
  	return X509_subject_name_cmp(*a,*b);
  	}
  #endif
  
  int X509_verify_cert(X509_STORE_CTX *ctx)
  	{
  	X509 *x,*xtmp,*chain_ss=NULL;
  	int bad_chain = 0;
  	X509_VERIFY_PARAM *param = ctx->param;
  	int depth,i,ok=0;
  	int num;
  	int (*cb)(int xok,X509_STORE_CTX *xctx);
  	STACK_OF(X509) *sktmp=NULL;
  	if (ctx->cert == NULL)
  		{
  		X509err(X509_F_X509_VERIFY_CERT,X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
  		return -1;
  		}
  
  	cb=ctx->verify_cb;
  
  	/* first we make sure the chain we are going to build is
  	 * present and that the first entry is in place */
  	if (ctx->chain == NULL)
  		{
  		if (	((ctx->chain=sk_X509_new_null()) == NULL) ||
  			(!sk_X509_push(ctx->chain,ctx->cert)))
  			{
  			X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
  			goto end;
  			}
  		CRYPTO_add(&ctx->cert->references,1,CRYPTO_LOCK_X509);
  		ctx->last_untrusted=1;
  		}
  
  	/* We use a temporary STACK so we can chop and hack at it */
  	if (ctx->untrusted != NULL
  	    && (sktmp=sk_X509_dup(ctx->untrusted)) == NULL)
  		{
  		X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
  		goto end;
  		}
  
  	num=sk_X509_num(ctx->chain);
  	x=sk_X509_value(ctx->chain,num-1);
  	depth=param->depth;
  
  
  	for (;;)
  		{
  		/* If we have enough, we break */
  		if (depth < num) break; /* FIXME: If this happens, we should take
  		                         * note of it and, if appropriate, use the
  		                         * X509_V_ERR_CERT_CHAIN_TOO_LONG error
  		                         * code later.
  		                         */
  
  		/* If we are self signed, we break */
  		if (ctx->check_issued(ctx, x,x)) break;
  
  		/* If we were passed a cert chain, use it first */
  		if (ctx->untrusted != NULL)
  			{
  			xtmp=find_issuer(ctx, sktmp,x);
  			if (xtmp != NULL)
  				{
  				if (!sk_X509_push(ctx->chain,xtmp))
  					{
  					X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
  					goto end;
  					}
  				CRYPTO_add(&xtmp->references,1,CRYPTO_LOCK_X509);
  				(void)sk_X509_delete_ptr(sktmp,xtmp);
  				ctx->last_untrusted++;
  				x=xtmp;
  				num++;
  				/* reparse the full chain for
  				 * the next one */
  				continue;
  				}
  			}
  		break;
  		}
  
  	/* at this point, chain should contain a list of untrusted
  	 * certificates.  We now need to add at least one trusted one,
  	 * if possible, otherwise we complain. */
  
  	/* Examine last certificate in chain and see if it
   	 * is self signed.
   	 */
  
  	i=sk_X509_num(ctx->chain);
  	x=sk_X509_value(ctx->chain,i-1);
  	if (ctx->check_issued(ctx, x, x))
  		{
  		/* we have a self signed certificate */
  		if (sk_X509_num(ctx->chain) == 1)
  			{
  			/* We have a single self signed certificate: see if
  			 * we can find it in the store. We must have an exact
  			 * match to avoid possible impersonation.
  			 */
  			ok = ctx->get_issuer(&xtmp, ctx, x);
  			if ((ok <= 0) || X509_cmp(x, xtmp)) 
  				{
  				ctx->error=X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT;
  				ctx->current_cert=x;
  				ctx->error_depth=i-1;
  				if (ok == 1) X509_free(xtmp);
  				bad_chain = 1;
  				ok=cb(0,ctx);
  				if (!ok) goto end;
  				}
  			else 
  				{
  				/* We have a match: replace certificate with store version
  				 * so we get any trust settings.
  				 */
  				X509_free(x);
  				x = xtmp;
  				(void)sk_X509_set(ctx->chain, i - 1, x);
  				ctx->last_untrusted=0;
  				}
  			}
  		else
  			{
  			/* extract and save self signed certificate for later use */
  			chain_ss=sk_X509_pop(ctx->chain);
  			ctx->last_untrusted--;
  			num--;
  			x=sk_X509_value(ctx->chain,num-1);
  			}
  		}
  
  	/* We now lookup certs from the certificate store */
  	for (;;)
  		{
  		/* If we have enough, we break */
  		if (depth < num) break;
  
  		/* If we are self signed, we break */
  		if (ctx->check_issued(ctx,x,x)) break;
  
  		ok = ctx->get_issuer(&xtmp, ctx, x);
  
  		if (ok < 0) return ok;
  		if (ok == 0) break;
  
  		x = xtmp;
  		if (!sk_X509_push(ctx->chain,x))
  			{
  			X509_free(xtmp);
  			X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
  			return 0;
  			}
  		num++;
  		}
  
  	/* we now have our chain, lets check it... */
  
  	/* Is last certificate looked up self signed? */
  	if (!ctx->check_issued(ctx,x,x))
  		{
  		if ((chain_ss == NULL) || !ctx->check_issued(ctx, x, chain_ss))
  			{
  			if (ctx->last_untrusted >= num)
  				ctx->error=X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY;
  			else
  				ctx->error=X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT;
  			ctx->current_cert=x;
  			}
  		else
  			{
  
  			sk_X509_push(ctx->chain,chain_ss);
  			num++;
  			ctx->last_untrusted=num;
  			ctx->current_cert=chain_ss;
  			ctx->error=X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN;
  			chain_ss=NULL;
  			}
  
  		ctx->error_depth=num-1;
  		bad_chain = 1;
  		ok=cb(0,ctx);
  		if (!ok) goto end;
  		}
  
  	/* We have the chain complete: now we need to check its purpose */
  	ok = check_chain_extensions(ctx);
  
  	if (!ok) goto end;
  
  	/* The chain extensions are OK: check trust */
  
  	if (param->trust > 0) ok = check_trust(ctx);
  
  	if (!ok) goto end;
  
  	/* We may as well copy down any DSA parameters that are required */
  	X509_get_pubkey_parameters(NULL,ctx->chain);
  
  	/* Check revocation status: we do this after copying parameters
  	 * because they may be needed for CRL signature verification.
  	 */
  
  	ok = ctx->check_revocation(ctx);
  	if(!ok) goto end;
  
  	/* At this point, we have a chain and need to verify it */
  	if (ctx->verify != NULL)
  		ok=ctx->verify(ctx);
  	else
  		ok=internal_verify(ctx);
  	if(!ok) goto end;
  
  #ifndef OPENSSL_NO_RFC3779
  	/* RFC 3779 path validation, now that CRL check has been done */
  	ok = v3_asid_validate_path(ctx);
  	if (!ok) goto end;
  	ok = v3_addr_validate_path(ctx);
  	if (!ok) goto end;
  #endif
  
  	/* If we get this far evaluate policies */
  	if (!bad_chain && (ctx->param->flags & X509_V_FLAG_POLICY_CHECK))
  		ok = ctx->check_policy(ctx);
  	if(!ok) goto end;
  	if (0)
  		{
  end:
  		X509_get_pubkey_parameters(NULL,ctx->chain);
  		}
  	if (sktmp != NULL) sk_X509_free(sktmp);
  	if (chain_ss != NULL) X509_free(chain_ss);
  	return ok;
  	}
  
  
  /* Given a STACK_OF(X509) find the issuer of cert (if any)
   */
  
  static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
  {
  	int i;
  	X509 *issuer;
  	for (i = 0; i < sk_X509_num(sk); i++)
  		{
  		issuer = sk_X509_value(sk, i);
  		if (ctx->check_issued(ctx, x, issuer))
  			return issuer;
  		}
  	return NULL;
  }
  
  /* Given a possible certificate and issuer check them */
  
  static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
  {
  	int ret;
  	ret = X509_check_issued(issuer, x);
  	if (ret == X509_V_OK)
  		return 1;
  	/* If we haven't asked for issuer errors don't set ctx */
  	if (!(ctx->param->flags & X509_V_FLAG_CB_ISSUER_CHECK))
  		return 0;
  
  	ctx->error = ret;
  	ctx->current_cert = x;
  	ctx->current_issuer = issuer;
  	return ctx->verify_cb(0, ctx);
  	return 0;
  }
  
  /* Alternative lookup method: look from a STACK stored in other_ctx */
  
  static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x)
  {
  	*issuer = find_issuer(ctx, ctx->other_ctx, x);
  	if (*issuer)
  		{
  		CRYPTO_add(&(*issuer)->references,1,CRYPTO_LOCK_X509);
  		return 1;
  		}
  	else
  		return 0;
  }
  	
  
  /* Check a certificate chains extensions for consistency
   * with the supplied purpose
   */
  
  static int check_chain_extensions(X509_STORE_CTX *ctx)
  {
  #ifdef OPENSSL_NO_CHAIN_VERIFY
  	return 1;
  #else
  	int i, ok=0, must_be_ca, plen = 0;
  	X509 *x;
  	int (*cb)(int xok,X509_STORE_CTX *xctx);
  	int proxy_path_length = 0;
  	int allow_proxy_certs =
  		!!(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
  	cb=ctx->verify_cb;
  
  	/* must_be_ca can have 1 of 3 values:
  	   -1: we accept both CA and non-CA certificates, to allow direct
  	       use of self-signed certificates (which are marked as CA).
  	   0:  we only accept non-CA certificates.  This is currently not
  	       used, but the possibility is present for future extensions.
  	   1:  we only accept CA certificates.  This is currently used for
  	       all certificates in the chain except the leaf certificate.
  	*/
  	must_be_ca = -1;
  
  	/* A hack to keep people who don't want to modify their software
  	   happy */
  	if (getenv("OPENSSL_ALLOW_PROXY_CERTS"))
  		allow_proxy_certs = 1;
  
  	/* Check all untrusted certificates */
  	for (i = 0; i < ctx->last_untrusted; i++)
  		{
  		int ret;
  		x = sk_X509_value(ctx->chain, i);
  		if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
  			&& (x->ex_flags & EXFLAG_CRITICAL))
  			{
  			ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION;
  			ctx->error_depth = i;
  			ctx->current_cert = x;
  			ok=cb(0,ctx);
  			if (!ok) goto end;
  			}
  		if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY))
  			{
  			ctx->error = X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED;
  			ctx->error_depth = i;
  			ctx->current_cert = x;
  			ok=cb(0,ctx);
  			if (!ok) goto end;
  			}
  		ret = X509_check_ca(x);
  		switch(must_be_ca)
  			{
  		case -1:
  			if ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
  				&& (ret != 1) && (ret != 0))
  				{
  				ret = 0;
  				ctx->error = X509_V_ERR_INVALID_CA;
  				}
  			else
  				ret = 1;
  			break;
  		case 0:
  			if (ret != 0)
  				{
  				ret = 0;
  				ctx->error = X509_V_ERR_INVALID_NON_CA;
  				}
  			else
  				ret = 1;
  			break;
  		default:
  			if ((ret == 0)
  				|| ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
  					&& (ret != 1)))
  				{
  				ret = 0;
  				ctx->error = X509_V_ERR_INVALID_CA;
  				}
  			else
  				ret = 1;
  			break;
  			}
  		if (ret == 0)
  			{
  			ctx->error_depth = i;
  			ctx->current_cert = x;
  			ok=cb(0,ctx);
  			if (!ok) goto end;
  			}
  		if (ctx->param->purpose > 0)
  			{
  			ret = X509_check_purpose(x, ctx->param->purpose,
  				must_be_ca > 0);
  			if ((ret == 0)
  				|| ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
  					&& (ret != 1)))
  				{
  				ctx->error = X509_V_ERR_INVALID_PURPOSE;
  				ctx->error_depth = i;
  				ctx->current_cert = x;
  				ok=cb(0,ctx);
  				if (!ok) goto end;
  				}
  			}
  		/* Check pathlen if not self issued */
  		if ((i > 1) && !(x->ex_flags & EXFLAG_SI)
  			   && (x->ex_pathlen != -1)
  			   && (plen > (x->ex_pathlen + proxy_path_length + 1)))
  			{
  			ctx->error = X509_V_ERR_PATH_LENGTH_EXCEEDED;
  			ctx->error_depth = i;
  			ctx->current_cert = x;
  			ok=cb(0,ctx);
  			if (!ok) goto end;
  			}
  		/* Increment path length if not self issued */
  		if (!(x->ex_flags & EXFLAG_SI))
  			plen++;
  		/* If this certificate is a proxy certificate, the next
  		   certificate must be another proxy certificate or a EE
  		   certificate.  If not, the next certificate must be a
  		   CA certificate.  */
  		if (x->ex_flags & EXFLAG_PROXY)
  			{
  			if (x->ex_pcpathlen != -1 && i > x->ex_pcpathlen)
  				{
  				ctx->error =
  					X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED;
  				ctx->error_depth = i;
  				ctx->current_cert = x;
  				ok=cb(0,ctx);
  				if (!ok) goto end;
  				}
  			proxy_path_length++;
  			must_be_ca = 0;
  			}
  		else
  			must_be_ca = 1;
  		}
  	ok = 1;
   end:
  	return ok;
  #endif
  }
  
  static int check_trust(X509_STORE_CTX *ctx)
  {
  #ifdef OPENSSL_NO_CHAIN_VERIFY
  	return 1;
  #else
  	int i, ok;
  	X509 *x;
  	int (*cb)(int xok,X509_STORE_CTX *xctx);
  	cb=ctx->verify_cb;
  /* For now just check the last certificate in the chain */
  	i = sk_X509_num(ctx->chain) - 1;
  	x = sk_X509_value(ctx->chain, i);
  	ok = X509_check_trust(x, ctx->param->trust, 0);
  	if (ok == X509_TRUST_TRUSTED)
  		return 1;
  	ctx->error_depth = i;
  	ctx->current_cert = x;
  	if (ok == X509_TRUST_REJECTED)
  		ctx->error = X509_V_ERR_CERT_REJECTED;
  	else
  		ctx->error = X509_V_ERR_CERT_UNTRUSTED;
  	ok = cb(0, ctx);
  	return ok;
  #endif
  }
  
  static int check_revocation(X509_STORE_CTX *ctx)
  	{
  	int i, last, ok;
  	if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
  		return 1;
  	if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
  		last = sk_X509_num(ctx->chain) - 1;
  	else
  		last = 0;
  	for(i = 0; i <= last; i++)
  		{
  		ctx->error_depth = i;
  		ok = check_cert(ctx);
  		if (!ok) return ok;
  		}
  	return 1;
  	}
  
  static int check_cert(X509_STORE_CTX *ctx)
  	{
  	X509_CRL *crl = NULL;
  	X509 *x;
  	int ok, cnum;
  	cnum = ctx->error_depth;
  	x = sk_X509_value(ctx->chain, cnum);
  	ctx->current_cert = x;
  	/* Try to retrieve relevant CRL */
  	ok = ctx->get_crl(ctx, &crl, x);
  	/* If error looking up CRL, nothing we can do except
  	 * notify callback
  	 */
  	if(!ok)
  		{
  		ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
  		ok = ctx->verify_cb(0, ctx);
  		goto err;
  		}
  	ctx->current_crl = crl;
  	ok = ctx->check_crl(ctx, crl);
  	if (!ok) goto err;
  	ok = ctx->cert_crl(ctx, crl, x);
  	err:
  	ctx->current_crl = NULL;
  	X509_CRL_free(crl);
  	return ok;
  
  	}
  
  /* Check CRL times against values in X509_STORE_CTX */
  
  static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
  	{
  	time_t *ptime;
  	int i;
  	ctx->current_crl = crl;
  	if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
  		ptime = &ctx->param->check_time;
  	else
  		ptime = NULL;
  
  	i=X509_cmp_time(X509_CRL_get_lastUpdate(crl), ptime);
  	if (i == 0)
  		{
  		ctx->error=X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD;
  		if (!notify || !ctx->verify_cb(0, ctx))
  			return 0;
  		}
  
  	if (i > 0)
  		{
  		ctx->error=X509_V_ERR_CRL_NOT_YET_VALID;
  		if (!notify || !ctx->verify_cb(0, ctx))
  			return 0;
  		}
  
  	if(X509_CRL_get_nextUpdate(crl))
  		{
  		i=X509_cmp_time(X509_CRL_get_nextUpdate(crl), ptime);
  
  		if (i == 0)
  			{
  			ctx->error=X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD;
  			if (!notify || !ctx->verify_cb(0, ctx))
  				return 0;
  			}
  
  		if (i < 0)
  			{
  			ctx->error=X509_V_ERR_CRL_HAS_EXPIRED;
  			if (!notify || !ctx->verify_cb(0, ctx))
  				return 0;
  			}
  		}
  
  	ctx->current_crl = NULL;
  
  	return 1;
  	}
  
  /* Lookup CRLs from the supplied list. Look for matching isser name
   * and validity. If we can't find a valid CRL return the last one
   * with matching name. This gives more meaningful error codes. Otherwise
   * we'd get a CRL not found error if a CRL existed with matching name but
   * was invalid.
   */
  
  static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
  			X509_NAME *nm, STACK_OF(X509_CRL) *crls)
  	{
  	int i;
  	X509_CRL *crl, *best_crl = NULL;
  	for (i = 0; i < sk_X509_CRL_num(crls); i++)
  		{
  		crl = sk_X509_CRL_value(crls, i);
  		if (X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))
  			continue;
  		if (check_crl_time(ctx, crl, 0))
  			{
  			*pcrl = crl;
  			CRYPTO_add(&crl->references, 1, CRYPTO_LOCK_X509);
  			return 1;
  			}
  		best_crl = crl;
  		}
  	if (best_crl)
  		{
  		*pcrl = best_crl;
  		CRYPTO_add(&best_crl->references, 1, CRYPTO_LOCK_X509);
  		}
  		
  	return 0;
  	}
  
  /* Retrieve CRL corresponding to certificate: currently just a
   * subject lookup: maybe use AKID later...
   */
  static int get_crl(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509 *x)
  	{
  	int ok;
  	X509_CRL *crl = NULL;
  	X509_OBJECT xobj;
  	X509_NAME *nm;
  	nm = X509_get_issuer_name(x);
  	ok = get_crl_sk(ctx, &crl, nm, ctx->crls);
  	if (ok)
  		{
  		*pcrl = crl;
  		return 1;
  		}
  
  	ok = X509_STORE_get_by_subject(ctx, X509_LU_CRL, nm, &xobj);
  
  	if (!ok)
  		{
  		/* If we got a near match from get_crl_sk use that */
  		if (crl)
  			{
  			*pcrl = crl;
  			return 1;
  			}
  		return 0;
  		}
  
  	*pcrl = xobj.data.crl;
  	if (crl)
  		X509_CRL_free(crl);
  	return 1;
  	}
  
  /* Check CRL validity */
  static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
  	{
  	X509 *issuer = NULL;
  	EVP_PKEY *ikey = NULL;
  	int ok = 0, chnum, cnum;
  	cnum = ctx->error_depth;
  	chnum = sk_X509_num(ctx->chain) - 1;
  	/* Find CRL issuer: if not last certificate then issuer
  	 * is next certificate in chain.
  	 */
  	if(cnum < chnum)
  		issuer = sk_X509_value(ctx->chain, cnum + 1);
  	else
  		{
  		issuer = sk_X509_value(ctx->chain, chnum);
  		/* If not self signed, can't check signature */
  		if(!ctx->check_issued(ctx, issuer, issuer))
  			{
  			ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER;
  			ok = ctx->verify_cb(0, ctx);
  			if(!ok) goto err;
  			}
  		}
  
  	if(issuer)
  		{
  		/* Check for cRLSign bit if keyUsage present */
  		if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
  			!(issuer->ex_kusage & KU_CRL_SIGN))
  			{
  			ctx->error = X509_V_ERR_KEYUSAGE_NO_CRL_SIGN;
  			ok = ctx->verify_cb(0, ctx);
  			if(!ok) goto err;
  			}
  
  		/* Attempt to get issuer certificate public key */
  		ikey = X509_get_pubkey(issuer);
  
  		if(!ikey)
  			{
  			ctx->error=X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
  			ok = ctx->verify_cb(0, ctx);
  			if (!ok) goto err;
  			}
  		else
  			{
  			/* Verify CRL signature */
  			if(X509_CRL_verify(crl, ikey) <= 0)
  				{
  				ctx->error=X509_V_ERR_CRL_SIGNATURE_FAILURE;
  				ok = ctx->verify_cb(0, ctx);
  				if (!ok) goto err;
  				}
  			}
  		}
  
  	ok = check_crl_time(ctx, crl, 1);
  	if (!ok)
  		goto err;
  
  	ok = 1;
  
  	err:
  	EVP_PKEY_free(ikey);
  	return ok;
  	}
  
  /* Check certificate against CRL */
  static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
  	{
  	int idx, ok;
  	X509_REVOKED rtmp;
  	STACK_OF(X509_EXTENSION) *exts;
  	X509_EXTENSION *ext;
  	/* Look for serial number of certificate in CRL */
  	rtmp.serialNumber = X509_get_serialNumber(x);
  	/* Sort revoked into serial number order if not already sorted.
  	 * Do this under a lock to avoid race condition.
   	 */
  	if (!sk_X509_REVOKED_is_sorted(crl->crl->revoked))
  		{
  		CRYPTO_w_lock(CRYPTO_LOCK_X509_CRL);
  		sk_X509_REVOKED_sort(crl->crl->revoked);
  		CRYPTO_w_unlock(CRYPTO_LOCK_X509_CRL);
  		}
  	idx = sk_X509_REVOKED_find(crl->crl->revoked, &rtmp);
  	/* If found assume revoked: want something cleverer than
  	 * this to handle entry extensions in V2 CRLs.
  	 */
  	if(idx >= 0)
  		{
  		ctx->error = X509_V_ERR_CERT_REVOKED;
  		ok = ctx->verify_cb(0, ctx);
  		if (!ok) return 0;
  		}
  
  	if (ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
  		return 1;
  
  	/* See if we have any critical CRL extensions: since we
  	 * currently don't handle any CRL extensions the CRL must be
  	 * rejected. 
  	 * This code accesses the X509_CRL structure directly: applications
  	 * shouldn't do this.
  	 */
  
  	exts = crl->crl->extensions;
  
  	for (idx = 0; idx < sk_X509_EXTENSION_num(exts); idx++)
  		{
  		ext = sk_X509_EXTENSION_value(exts, idx);
  		if (ext->critical > 0)
  			{
  			ctx->error =
  				X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION;
  			ok = ctx->verify_cb(0, ctx);
  			if(!ok) return 0;
  			break;
  			}
  		}
  	return 1;
  	}
  
  static int check_policy(X509_STORE_CTX *ctx)
  	{
  	int ret;
  	ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain,
  				ctx->param->policies, ctx->param->flags);
  	if (ret == 0)
  		{
  		X509err(X509_F_CHECK_POLICY,ERR_R_MALLOC_FAILURE);
  		return 0;
  		}
  	/* Invalid or inconsistent extensions */
  	if (ret == -1)
  		{
  		/* Locate certificates with bad extensions and notify
  		 * callback.
  		 */
  		X509 *x;
  		int i;
  		for (i = 1; i < sk_X509_num(ctx->chain); i++)
  			{
  			x = sk_X509_value(ctx->chain, i);
  			if (!(x->ex_flags & EXFLAG_INVALID_POLICY))
  				continue;
  			ctx->current_cert = x;
  			ctx->error = X509_V_ERR_INVALID_POLICY_EXTENSION;
  			ret = ctx->verify_cb(0, ctx);
  			}
  		return 1;
  		}
  	if (ret == -2)
  		{
  		ctx->current_cert = NULL;
  		ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY;
  		return ctx->verify_cb(0, ctx);
  		}
  
  	if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY)
  		{
  		ctx->current_cert = NULL;
  		ctx->error = X509_V_OK;
  		if (!ctx->verify_cb(2, ctx))
  			return 0;
  		}
  
  	return 1;
  	}
  
  static int check_cert_time(X509_STORE_CTX *ctx, X509 *x)
  	{
  	time_t *ptime;
  	int i;
  
  	if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
  		ptime = &ctx->param->check_time;
  	else
  		ptime = NULL;
  
  	i=X509_cmp_time(X509_get_notBefore(x), ptime);
  	if (i == 0)
  		{
  		ctx->error=X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD;
  		ctx->current_cert=x;
  		if (!ctx->verify_cb(0, ctx))
  			return 0;
  		}
  
  	if (i > 0)
  		{
  		ctx->error=X509_V_ERR_CERT_NOT_YET_VALID;
  		ctx->current_cert=x;
  		if (!ctx->verify_cb(0, ctx))
  			return 0;
  		}
  
  	i=X509_cmp_time(X509_get_notAfter(x), ptime);
  	if (i == 0)
  		{
  		ctx->error=X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD;
  		ctx->current_cert=x;
  		if (!ctx->verify_cb(0, ctx))
  			return 0;
  		}
  
  	if (i < 0)
  		{
  		ctx->error=X509_V_ERR_CERT_HAS_EXPIRED;
  		ctx->current_cert=x;
  		if (!ctx->verify_cb(0, ctx))
  			return 0;
  		}
  
  	return 1;
  	}
  
  static int internal_verify(X509_STORE_CTX *ctx)
  	{
  	int ok=0,n;
  	X509 *xs,*xi;
  	EVP_PKEY *pkey=NULL;
  	int (*cb)(int xok,X509_STORE_CTX *xctx);
  
  	cb=ctx->verify_cb;
  
  	n=sk_X509_num(ctx->chain);
  	ctx->error_depth=n-1;
  	n--;
  	xi=sk_X509_value(ctx->chain,n);
  
  	if (ctx->check_issued(ctx, xi, xi))
  		xs=xi;
  	else
  		{
  		if (n <= 0)
  			{
  			ctx->error=X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE;
  			ctx->current_cert=xi;
  			ok=cb(0,ctx);
  			goto end;
  			}
  		else
  			{
  			n--;
  			ctx->error_depth=n;
  			xs=sk_X509_value(ctx->chain,n);
  			}
  		}
  
  /*	ctx->error=0;  not needed */
  	while (n >= 0)
  		{
  		ctx->error_depth=n;
  
  		/* Skip signature check for self signed certificates unless
  		 * explicitly asked for. It doesn't add any security and
  		 * just wastes time.
  		 */
  		if (!xs->valid && (xs != xi || (ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE)))
  			{
  			if ((pkey=X509_get_pubkey(xi)) == NULL)
  				{
  				ctx->error=X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
  				ctx->current_cert=xi;
  				ok=(*cb)(0,ctx);
  				if (!ok) goto end;
  				}
  			else if (X509_verify(xs,pkey) <= 0)
  				{
  				ctx->error=X509_V_ERR_CERT_SIGNATURE_FAILURE;
  				ctx->current_cert=xs;
  				ok=(*cb)(0,ctx);
  				if (!ok)
  					{
  					EVP_PKEY_free(pkey);
  					goto end;
  					}
  				}
  			EVP_PKEY_free(pkey);
  			pkey=NULL;
  			}
  
  		xs->valid = 1;
  
  		ok = check_cert_time(ctx, xs);
  		if (!ok)
  			goto end;
  
  		/* The last error (if any) is still in the error value */
  		ctx->current_issuer=xi;
  		ctx->current_cert=xs;
  		ok=(*cb)(1,ctx);
  		if (!ok) goto end;
  
  		n--;
  		if (n >= 0)
  			{
  			xi=xs;
  			xs=sk_X509_value(ctx->chain,n);
  			}
  		}
  	ok=1;
  end:
  	return ok;
  	}
  
  int X509_cmp_current_time(ASN1_TIME *ctm)
  {
  	return X509_cmp_time(ctm, NULL);
  }
  
  int X509_cmp_time(ASN1_TIME *ctm, time_t *cmp_time)
  	{
  	char *str;
  	ASN1_TIME atm;
  	long offset;
  	char buff1[24],buff2[24],*p;
  	int i,j;
  
  	p=buff1;
  	i=ctm->length;
  	str=(char *)ctm->data;
  	if (ctm->type == V_ASN1_UTCTIME)
  		{
  		if ((i < 11) || (i > 17)) return 0;
  		memcpy(p,str,10);
  		p+=10;
  		str+=10;
  		}
  	else
  		{
  		if (i < 13) return 0;
  		memcpy(p,str,12);
  		p+=12;
  		str+=12;
  		}
  
  	if ((*str == 'Z') || (*str == '-') || (*str == '+'))
  		{ *(p++)='0'; *(p++)='0'; }
  	else
  		{ 
  		*(p++)= *(str++);
  		*(p++)= *(str++);
  		/* Skip any fractional seconds... */
  		if (*str == '.')
  			{
  			str++;
  			while ((*str >= '0') && (*str <= '9')) str++;
  			}
  		
  		}
  	*(p++)='Z';
  	*(p++)='\0';
  
  	if (*str == 'Z')
  		offset=0;
  	else
  		{
  		if ((*str != '+') && (*str != '-'))
  			return 0;
  		offset=((str[1]-'0')*10+(str[2]-'0'))*60;
  		offset+=(str[3]-'0')*10+(str[4]-'0');
  		if (*str == '-')
  			offset= -offset;
  		}
  	atm.type=ctm->type;
  	atm.length=sizeof(buff2);
  	atm.data=(unsigned char *)buff2;
  
  	if (X509_time_adj(&atm,-offset*60, cmp_time) == NULL)
  		return 0;
  
  	if (ctm->type == V_ASN1_UTCTIME)
  		{
  		i=(buff1[0]-'0')*10+(buff1[1]-'0');
  		if (i < 50) i+=100; /* cf. RFC 2459 */
  		j=(buff2[0]-'0')*10+(buff2[1]-'0');
  		if (j < 50) j+=100;
  
  		if (i < j) return -1;
  		if (i > j) return 1;
  		}
  	i=strcmp(buff1,buff2);
  	if (i == 0) /* wait a second then return younger :-) */
  		return -1;
  	else
  		return i;
  	}
  
  ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj)
  {
  	return X509_time_adj(s, adj, NULL);
  }
  
  ASN1_TIME *X509_time_adj(ASN1_TIME *s, long adj, time_t *in_tm)
  	{
  	time_t t;
  	int type = -1;
  
  	if (in_tm) t = *in_tm;
  	else time(&t);
  
  	t+=adj;
  	if (s) type = s->type;
  	if (type == V_ASN1_UTCTIME) return ASN1_UTCTIME_set(s,t);
  	if (type == V_ASN1_GENERALIZEDTIME) return ASN1_GENERALIZEDTIME_set(s, t);
  	return ASN1_TIME_set(s, t);
  	}
  
  int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
  	{
  	EVP_PKEY *ktmp=NULL,*ktmp2;
  	int i,j;
  
  	if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey)) return 1;
  
  	for (i=0; i<sk_X509_num(chain); i++)
  		{
  		ktmp=X509_get_pubkey(sk_X509_value(chain,i));
  		if (ktmp == NULL)
  			{
  			X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
  			return 0;
  			}
  		if (!EVP_PKEY_missing_parameters(ktmp))
  			break;
  		else
  			{
  			EVP_PKEY_free(ktmp);
  			ktmp=NULL;
  			}
  		}
  	if (ktmp == NULL)
  		{
  		X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN);
  		return 0;
  		}
  
  	/* first, populate the other certs */
  	for (j=i-1; j >= 0; j--)
  		{
  		ktmp2=X509_get_pubkey(sk_X509_value(chain,j));
  		EVP_PKEY_copy_parameters(ktmp2,ktmp);
  		EVP_PKEY_free(ktmp2);
  		}
  	
  	if (pkey != NULL) EVP_PKEY_copy_parameters(pkey,ktmp);
  	EVP_PKEY_free(ktmp);
  	return 1;
  	}
  
  int X509_STORE_CTX_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
  	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
  	{
  	/* This function is (usually) called only once, by
  	 * SSL_get_ex_data_X509_STORE_CTX_idx (ssl/ssl_cert.c). */
  	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_X509_STORE_CTX, argl, argp,
  			new_func, dup_func, free_func);
  	}
  
  int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data)
  	{
  	return CRYPTO_set_ex_data(&ctx->ex_data,idx,data);
  	}
  
  void *X509_STORE_CTX_get_ex_data(X509_STORE_CTX *ctx, int idx)
  	{
  	return CRYPTO_get_ex_data(&ctx->ex_data,idx);
  	}
  
  int X509_STORE_CTX_get_error(X509_STORE_CTX *ctx)
  	{
  	return ctx->error;
  	}
  
  void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err)
  	{
  	ctx->error=err;
  	}
  
  int X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx)
  	{
  	return ctx->error_depth;
  	}
  
  X509 *X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx)
  	{
  	return ctx->current_cert;
  	}
  
  STACK_OF(X509) *X509_STORE_CTX_get_chain(X509_STORE_CTX *ctx)
  	{
  	return ctx->chain;
  	}
  
  STACK_OF(X509) *X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx)
  	{
  	int i;
  	X509 *x;
  	STACK_OF(X509) *chain;
  	if (!ctx->chain || !(chain = sk_X509_dup(ctx->chain))) return NULL;
  	for (i = 0; i < sk_X509_num(chain); i++)
  		{
  		x = sk_X509_value(chain, i);
  		CRYPTO_add(&x->references, 1, CRYPTO_LOCK_X509);
  		}
  	return chain;
  	}
  
  void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x)
  	{
  	ctx->cert=x;
  	}
  
  void X509_STORE_CTX_set_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
  	{
  	ctx->untrusted=sk;
  	}
  
  void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk)
  	{
  	ctx->crls=sk;
  	}
  
  int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose)
  	{
  	return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0);
  	}
  
  int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust)
  	{
  	return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust);
  	}
  
  /* This function is used to set the X509_STORE_CTX purpose and trust
   * values. This is intended to be used when another structure has its
   * own trust and purpose values which (if set) will be inherited by
   * the ctx. If they aren't set then we will usually have a default
   * purpose in mind which should then be used to set the trust value.
   * An example of this is SSL use: an SSL structure will have its own
   * purpose and trust settings which the application can set: if they
   * aren't set then we use the default of SSL client/server.
   */
  
  int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose,
  				int purpose, int trust)
  {
  	int idx;
  	/* If purpose not set use default */
  	if (!purpose) purpose = def_purpose;
  	/* If we have a purpose then check it is valid */
  	if (purpose)
  		{
  		X509_PURPOSE *ptmp;
  		idx = X509_PURPOSE_get_by_id(purpose);
  		if (idx == -1)
  			{
  			X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
  						X509_R_UNKNOWN_PURPOSE_ID);
  			return 0;
  			}
  		ptmp = X509_PURPOSE_get0(idx);
  		if (ptmp->trust == X509_TRUST_DEFAULT)
  			{
  			idx = X509_PURPOSE_get_by_id(def_purpose);
  			if (idx == -1)
  				{
  				X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
  						X509_R_UNKNOWN_PURPOSE_ID);
  				return 0;
  				}
  			ptmp = X509_PURPOSE_get0(idx);
  			}
  		/* If trust not set then get from purpose default */
  		if (!trust) trust = ptmp->trust;
  		}
  	if (trust)
  		{
  		idx = X509_TRUST_get_by_id(trust);
  		if (idx == -1)
  			{
  			X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
  						X509_R_UNKNOWN_TRUST_ID);
  			return 0;
  			}
  		}
  
  	if (purpose && !ctx->param->purpose) ctx->param->purpose = purpose;
  	if (trust && !ctx->param->trust) ctx->param->trust = trust;
  	return 1;
  }
  
  X509_STORE_CTX *X509_STORE_CTX_new(void)
  {
  	X509_STORE_CTX *ctx;
  	ctx = (X509_STORE_CTX *)OPENSSL_malloc(sizeof(X509_STORE_CTX));
  	if (!ctx)
  		{
  		X509err(X509_F_X509_STORE_CTX_NEW,ERR_R_MALLOC_FAILURE);
  		return NULL;
  		}
  	memset(ctx, 0, sizeof(X509_STORE_CTX));
  	return ctx;
  }
  
  void X509_STORE_CTX_free(X509_STORE_CTX *ctx)
  {
  	X509_STORE_CTX_cleanup(ctx);
  	OPENSSL_free(ctx);
  }
  
  int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
  	     STACK_OF(X509) *chain)
  	{
  	int ret = 1;
  	ctx->ctx=store;
  	ctx->current_method=0;
  	ctx->cert=x509;
  	ctx->untrusted=chain;
  	ctx->crls = NULL;
  	ctx->last_untrusted=0;
  	ctx->other_ctx=NULL;
  	ctx->valid=0;
  	ctx->chain=NULL;
  	ctx->error=0;
  	ctx->explicit_policy=0;
  	ctx->error_depth=0;
  	ctx->current_cert=NULL;
  	ctx->current_issuer=NULL;
  	ctx->tree = NULL;
  
  	ctx->param = X509_VERIFY_PARAM_new();
  
  	if (!ctx->param)
  		{
  		X509err(X509_F_X509_STORE_CTX_INIT,ERR_R_MALLOC_FAILURE);
  		return 0;
  		}
  
  	/* Inherit callbacks and flags from X509_STORE if not set
  	 * use defaults.
  	 */
  
  
  	if (store)
  		ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param);
  	else
  		ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT|X509_VP_FLAG_ONCE;
  
  	if (store)
  		{
  		ctx->verify_cb = store->verify_cb;
  		ctx->cleanup = store->cleanup;
  		}
  	else
  		ctx->cleanup = 0;
  
  	if (ret)
  		ret = X509_VERIFY_PARAM_inherit(ctx->param,
  					X509_VERIFY_PARAM_lookup("default"));
  
  	if (ret == 0)
  		{
  		X509err(X509_F_X509_STORE_CTX_INIT,ERR_R_MALLOC_FAILURE);
  		return 0;
  		}
  
  	if (store && store->check_issued)
  		ctx->check_issued = store->check_issued;
  	else
  		ctx->check_issued = check_issued;
  
  	if (store && store->get_issuer)
  		ctx->get_issuer = store->get_issuer;
  	else
  		ctx->get_issuer = X509_STORE_CTX_get1_issuer;
  
  	if (store && store->verify_cb)
  		ctx->verify_cb = store->verify_cb;
  	else
  		ctx->verify_cb = null_callback;
  
  	if (store && store->verify)
  		ctx->verify = store->verify;
  	else
  		ctx->verify = internal_verify;
  
  	if (store && store->check_revocation)
  		ctx->check_revocation = store->check_revocation;
  	else
  		ctx->check_revocation = check_revocation;
  
  	if (store && store->get_crl)
  		ctx->get_crl = store->get_crl;
  	else
  		ctx->get_crl = get_crl;
  
  	if (store && store->check_crl)
  		ctx->check_crl = store->check_crl;
  	else
  		ctx->check_crl = check_crl;
  
  	if (store && store->cert_crl)
  		ctx->cert_crl = store->cert_crl;
  	else
  		ctx->cert_crl = cert_crl;
  
  	ctx->check_policy = check_policy;
  
  
  	/* This memset() can't make any sense anyway, so it's removed. As
  	 * X509_STORE_CTX_cleanup does a proper "free" on the ex_data, we put a
  	 * corresponding "new" here and remove this bogus initialisation. */
  	/* memset(&(ctx->ex_data),0,sizeof(CRYPTO_EX_DATA)); */
  	if(!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx,
  				&(ctx->ex_data)))
  		{
  		OPENSSL_free(ctx);
  		X509err(X509_F_X509_STORE_CTX_INIT,ERR_R_MALLOC_FAILURE);
  		return 0;
  		}
  	return 1;
  	}
  
  /* Set alternative lookup method: just a STACK of trusted certificates.
   * This avoids X509_STORE nastiness where it isn't needed.
   */
  
  void X509_STORE_CTX_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
  {
  	ctx->other_ctx = sk;
  	ctx->get_issuer = get_issuer_sk;
  }
  
  void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx)
  	{
  	if (ctx->cleanup) ctx->cleanup(ctx);
  	if (ctx->param != NULL)
  		{
  		X509_VERIFY_PARAM_free(ctx->param);
  		ctx->param=NULL;
  		}
  	if (ctx->tree != NULL)
  		{
  		X509_policy_tree_free(ctx->tree);
  		ctx->tree=NULL;
  		}
  	if (ctx->chain != NULL)
  		{
  		sk_X509_pop_free(ctx->chain,X509_free);
  		ctx->chain=NULL;
  		}
  	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data));
  	memset(&ctx->ex_data,0,sizeof(CRYPTO_EX_DATA));
  	}
  
  void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth)
  	{
  	X509_VERIFY_PARAM_set_depth(ctx->param, depth);
  	}
  
  void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags)
  	{
  	X509_VERIFY_PARAM_set_flags(ctx->param, flags);
  	}
  
  void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags, time_t t)
  	{
  	X509_VERIFY_PARAM_set_time(ctx->param, t);
  	}
  
  void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
  				  int (*verify_cb)(int, X509_STORE_CTX *))
  	{
  	ctx->verify_cb=verify_cb;
  	}
  
  X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(X509_STORE_CTX *ctx)
  	{
  	return ctx->tree;
  	}
  
  int X509_STORE_CTX_get_explicit_policy(X509_STORE_CTX *ctx)
  	{
  	return ctx->explicit_policy;
  	}
  
  int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name)
  	{
  	const X509_VERIFY_PARAM *param;
  	param = X509_VERIFY_PARAM_lookup(name);
  	if (!param)
  		return 0;
  	return X509_VERIFY_PARAM_inherit(ctx->param, param);
  	}
  
  X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx)
  	{
  	return ctx->param;
  	}
  
  void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param)
  	{
  	if (ctx->param)
  		X509_VERIFY_PARAM_free(ctx->param);
  	ctx->param = param;
  	}
  
  IMPLEMENT_STACK_OF(X509)
  IMPLEMENT_ASN1_SET_OF(X509)
  
  IMPLEMENT_STACK_OF(X509_NAME)
  
  IMPLEMENT_STACK_OF(X509_ATTRIBUTE)
  IMPLEMENT_ASN1_SET_OF(X509_ATTRIBUTE)
  