X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fx509%2Fx509_vfy.c;h=b6f16bb77220afcfda900d79a6d26d4380d5fef4;hp=cb7936f2b3d89658bdffa55fc43c2dffa84183c7;hb=a48fb0400c9c45d56144966b774998ebe37804ef;hpb=d43c4497ce1611373c3a3e5b433dfde4907d1a69

diff --git a/crypto/x509/x509_vfy.c b/crypto/x509/x509_vfy.c
index cb7936f2b3..b6f16bb772 100644
--- a/crypto/x509/x509_vfy.c
+++ b/crypto/x509/x509_vfy.c
@@ -69,6 +69,7 @@
 #include <openssl/x509.h>
 #include <openssl/x509v3.h>
 #include <openssl/objects.h>
+#include "x509_lcl.h"
 
 /* CRL score values */
 
@@ -113,6 +114,7 @@ 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_name_constraints(X509_STORE_CTX *ctx);
+static int check_id(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);
@@ -149,11 +151,45 @@ static int x509_subject_cmp(X509 **a, X509 **b)
 	return X509_subject_name_cmp(*a,*b);
 	}
 #endif
+/* Return 1 is a certificate is self signed */
+static int cert_self_signed(X509 *x)
+	{
+	X509_check_purpose(x, -1, 0);
+	if (x->ex_flags & EXFLAG_SS)
+		return 1;
+	else
+		return 0;
+	}
+
+/* Given a certificate try and find an exact match in the store */
+
+static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x)
+	{
+	STACK_OF(X509) *certs;
+	X509 *xtmp = NULL;
+	int i;
+	/* Lookup all certs with matching subject name */
+	certs = ctx->lookup_certs(ctx, X509_get_subject_name(x));
+	if (certs == NULL)
+		return NULL;
+	/* Look for exact match */
+	for (i = 0; i < sk_X509_num(certs); i++)
+		{
+		xtmp = sk_X509_value(certs, i);
+		if (!X509_cmp(xtmp, x))
+			break;
+		}
+	if (i < sk_X509_num(certs))
+		CRYPTO_add(&xtmp->references,1,CRYPTO_LOCK_X509);
+	else
+		xtmp = NULL;
+	sk_X509_pop_free(certs, X509_free);
+	return xtmp;
+	}
 
 int X509_verify_cert(X509_STORE_CTX *ctx)
 	{
 	X509 *x,*xtmp,*chain_ss=NULL;
-	X509_NAME *xn;
 	int bad_chain = 0;
 	X509_VERIFY_PARAM *param = ctx->param;
 	int depth,i,ok=0;
@@ -205,8 +241,23 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
 		                         */
 
 		/* If we are self signed, we break */
-		xn=X509_get_issuer_name(x);
-		if (ctx->check_issued(ctx, x,x)) break;
+		if (cert_self_signed(x))
+			break;
+		/* If asked see if we can find issuer in trusted store first */
+		if (ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST)
+			{
+			ok = ctx->get_issuer(&xtmp, ctx, x);
+			if (ok < 0)
+				return ok;
+			/* If successful for now free up cert so it
+			 * will be picked up again later.
+			 */
+			if (ok > 0)
+				{
+				X509_free(xtmp);
+				break;
+				}
+			}
 
 		/* If we were passed a cert chain, use it first */
 		if (ctx->untrusted != NULL)
@@ -242,8 +293,7 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
 
 	i=sk_X509_num(ctx->chain);
 	x=sk_X509_value(ctx->chain,i-1);
-	xn = X509_get_subject_name(x);
-	if (ctx->check_issued(ctx, x, x))
+	if (cert_self_signed(x))
 		{
 		/* we have a self signed certificate */
 		if (sk_X509_num(ctx->chain) == 1)
@@ -291,8 +341,8 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
 		if (depth < num) break;
 
 		/* If we are self signed, we break */
-		xn=X509_get_issuer_name(x);
-		if (ctx->check_issued(ctx,x,x)) break;
+		if (cert_self_signed(x))
+			break;
 
 		ok = ctx->get_issuer(&xtmp, ctx, x);
 
@@ -310,10 +360,17 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
 		}
 
 	/* we now have our chain, lets check it... */
-	xn=X509_get_issuer_name(x);
 
-	/* Is last certificate looked up self signed? */
-	if (!ctx->check_issued(ctx,x,x))
+	i = check_trust(ctx);
+
+	/* If explicitly rejected error */
+	if (i == X509_TRUST_REJECTED)
+		goto end;
+	/* If not explicitly trusted then indicate error unless it's
+	 * a single self signed certificate in which case we've indicated
+	 * an error already and set bad_chain == 1
+	 */
+	if (i != X509_TRUST_TRUSTED && !bad_chain)
 		{
 		if ((chain_ss == NULL) || !ctx->check_issued(ctx, x, chain_ss))
 			{
@@ -351,9 +408,7 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
 	
 	if (!ok) goto end;
 
-	/* The chain extensions are OK: check trust */
-
-	if (param->trust > 0) ok = check_trust(ctx);
+	ok = check_id(ctx);
 
 	if (!ok) goto end;
 
@@ -367,6 +422,17 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
 	ok = ctx->check_revocation(ctx);
 	if(!ok) goto end;
 
+	i = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain,
+							ctx->param->flags);
+	if (i != X509_V_OK)
+		{
+		ctx->error = i;
+		ctx->current_cert = sk_X509_value(ctx->chain, ctx->error_depth);
+		ok = cb(0, 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);
@@ -403,14 +469,18 @@ end:
 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
 {
 	int i;
-	X509 *issuer;
+	X509 *issuer, *rv = NULL;;
 	for (i = 0; i < sk_X509_num(sk); i++)
 		{
 		issuer = sk_X509_value(sk, i);
 		if (ctx->check_issued(ctx, x, issuer))
-			return issuer;
+			{
+			rv = issuer;
+			if (x509_check_cert_time(ctx, rv, 1))
+				break;
+			}
 		}
-	return NULL;
+	return rv;
 }
 
 /* Given a possible certificate and issuer check them */
@@ -418,7 +488,27 @@ static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
 {
 	int ret;
+	if (x == issuer)
+		return cert_self_signed(x);
 	ret = X509_check_issued(issuer, x);
+	if (ret == X509_V_OK)
+		{
+		int i;
+		X509 *ch;
+		/* Special case: single self signed certificate */
+		if (cert_self_signed(x) && sk_X509_num(ctx->chain) == 1)
+			return 1;
+		for (i = 0; i < sk_X509_num(ctx->chain); i++)
+			{
+			ch = sk_X509_value(ctx->chain, i);
+			if (ch == issuer || !X509_cmp(ch, issuer))
+				{
+				ret = X509_V_ERR_PATH_LOOP;
+				break;
+				}
+			}
+		}
+
 	if (ret == X509_V_OK)
 		return 1;
 	/* If we haven't asked for issuer errors don't set ctx */
@@ -645,30 +735,87 @@ static int check_name_constraints(X509_STORE_CTX *ctx)
 	return 1;
 	}
 
+static int check_id_error(X509_STORE_CTX *ctx, int errcode)
+	{
+	ctx->error = errcode;
+	ctx->current_cert = ctx->cert;
+	ctx->error_depth = 0;
+	return ctx->verify_cb(0, ctx);
+	}
+
+static int check_id(X509_STORE_CTX *ctx)
+	{
+	X509_VERIFY_PARAM *vpm = ctx->param;
+	X509_VERIFY_PARAM_ID *id = vpm->id;
+	X509 *x = ctx->cert;
+	if (id->host && X509_check_host(x, id->host, 0, id->hostflags) <= 0)
+		{
+		if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH))
+			return 0;
+		}
+	if (id->email && X509_check_email(x, id->email, id->emaillen, 0) <= 0)
+		{
+		if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH))
+			return 0;
+		}
+	if (id->ip && X509_check_ip(x, id->ip, id->iplen, 0) <= 0)
+		{
+		if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH))
+			return 0;
+		}
+	return 1;
+	}
+
 static int check_trust(X509_STORE_CTX *ctx)
 {
-#ifdef OPENSSL_NO_CHAIN_VERIFY
-	return 1;
-#else
 	int i, ok;
-	X509 *x;
+	X509 *x = NULL;
 	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
+	/* Check all trusted certificates in chain */
+	for (i = ctx->last_untrusted; i < sk_X509_num(ctx->chain); i++)
+		{
+		x = sk_X509_value(ctx->chain, i);
+		ok = X509_check_trust(x, ctx->param->trust, 0);
+		/* If explicitly trusted return trusted */
+		if (ok == X509_TRUST_TRUSTED)
+			return X509_TRUST_TRUSTED;
+		/* If explicitly rejected notify callback and reject if
+		 * not overridden.
+		 */
+		if (ok == X509_TRUST_REJECTED)
+			{
+			ctx->error_depth = i;
+			ctx->current_cert = x;
+			ctx->error = X509_V_ERR_CERT_REJECTED;
+			ok = cb(0, ctx);
+			if (!ok)
+				return X509_TRUST_REJECTED;
+			}
+		}
+	/* If we accept partial chains and have at least one trusted
+	 * certificate return success.
+	 */
+	if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN)
+		{
+		X509 *mx;
+		if (ctx->last_untrusted < sk_X509_num(ctx->chain))
+			return X509_TRUST_TRUSTED;
+		x = sk_X509_value(ctx->chain, 0);
+		mx = lookup_cert_match(ctx, x);
+		if (mx)
+			{
+			(void)sk_X509_set(ctx->chain, 0, mx);
+			X509_free(x);
+			ctx->last_untrusted = 0;
+			return X509_TRUST_TRUSTED;
+			}
+		}
+
+	/* If no trusted certs in chain at all return untrusted and
+	 * allow standard (no issuer cert) etc errors to be indicated.
+	 */
+	return X509_TRUST_UNTRUSTED;
 }
 
 static int check_revocation(X509_STORE_CTX *ctx)
@@ -679,7 +826,12 @@ static int check_revocation(X509_STORE_CTX *ctx)
 	if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
 		last = sk_X509_num(ctx->chain) - 1;
 	else
+		{
+		/* If checking CRL paths this isn't the EE certificate */
+		if (ctx->parent)
+			return 1;
 		last = 0;
+		}
 	for(i = 0; i <= last; i++)
 		{
 		ctx->error_depth = i;
@@ -694,13 +846,16 @@ static int check_cert(X509_STORE_CTX *ctx)
 	X509_CRL *crl = NULL, *dcrl = NULL;
 	X509 *x;
 	int ok, cnum;
+	unsigned int last_reasons;
 	cnum = ctx->error_depth;
 	x = sk_X509_value(ctx->chain, cnum);
 	ctx->current_cert = x;
 	ctx->current_issuer = NULL;
+	ctx->current_crl_score = 0;
 	ctx->current_reasons = 0;
 	while (ctx->current_reasons != CRLDP_ALL_REASONS)
 		{
+		last_reasons = ctx->current_reasons;
 		/* Try to retrieve relevant CRL */
 		if (ctx->get_crl)
 			ok = ctx->get_crl(ctx, &crl, x);
@@ -744,6 +899,15 @@ static int check_cert(X509_STORE_CTX *ctx)
 		X509_CRL_free(dcrl);
 		crl = NULL;
 		dcrl = NULL;
+		/* If reasons not updated we wont get anywhere by
+		 * another iteration, so exit loop.
+		 */
+		if (last_reasons == ctx->current_reasons)
+			{
+			ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
+			ok = ctx->verify_cb(0, ctx);
+			goto err;
+			}
 		}
 	err:
 	X509_CRL_free(crl);
@@ -820,10 +984,11 @@ static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
 			STACK_OF(X509_CRL) *crls)
 	{
 	int i, crl_score, best_score = *pscore;
-	unsigned int reasons, best_reasons;
+	unsigned int reasons, best_reasons = 0;
 	X509 *x = ctx->current_cert;
 	X509_CRL *crl, *best_crl = NULL;
-	X509 *crl_issuer, *best_crl_issuer = NULL;
+	X509 *crl_issuer = NULL, *best_crl_issuer = NULL;
+
 	for (i = 0; i < sk_X509_CRL_num(crls); i++)
 		{
 		crl = sk_X509_CRL_value(crls, i);
@@ -870,7 +1035,7 @@ static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid)
 	{
 	ASN1_OCTET_STRING *exta, *extb;
 	int i;
-	i = X509_CRL_get_ext_by_NID(a, nid, 0);
+	i = X509_CRL_get_ext_by_NID(a, nid, -1);
 	if (i >= 0)
 		{
 		/* Can't have multiple occurrences */
@@ -881,7 +1046,7 @@ static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid)
 	else
 		exta = NULL;
 
-	i = X509_CRL_get_ext_by_NID(b, nid, 0);
+	i = X509_CRL_get_ext_by_NID(b, nid, -1);
 
 	if (i >= 0)
 		{
@@ -1123,7 +1288,7 @@ static int check_crl_path(X509_STORE_CTX *ctx, X509 *x)
 	/* Verify CRL issuer */
 	ret = X509_verify_cert(&crl_ctx);
 
-	if (!ret)
+	if (ret <= 0)
 		goto err;
 
 	/* Check chain is acceptable */
@@ -1386,7 +1551,7 @@ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
 
 			if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH))
 				{
-				if (!check_crl_path(ctx, ctx->current_issuer))
+				if (check_crl_path(ctx, ctx->current_issuer) <= 0)
 					{
 					ctx->error = X509_V_ERR_CRL_PATH_VALIDATION_ERROR;
 					ok = ctx->verify_cb(0, ctx);
@@ -1422,6 +1587,15 @@ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
 			}
 		else
 			{
+			int rv;
+			rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags);
+			if (rv != X509_V_OK)
+				{
+				ctx->error=rv;
+				ok = ctx->verify_cb(0, ctx);
+				if (!ok)
+					goto err;
+				}
 			/* Verify CRL signature */
 			if(X509_CRL_verify(crl, ikey) <= 0)
 				{
@@ -1449,10 +1623,9 @@ static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
 	 * a certificate was revoked. This has since been changed since 
 	 * critical extension can change the meaning of CRL entries.
 	 */
-	if (crl->flags & EXFLAG_CRITICAL)
+	if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
+		&& (crl->flags & EXFLAG_CRITICAL))
 		{
-		if (ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
-			return 1;
 		ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION;
 		ok = ctx->verify_cb(0, ctx);
 		if(!ok)
@@ -1524,7 +1697,7 @@ static int check_policy(X509_STORE_CTX *ctx)
 	return 1;
 	}
 
-static int check_cert_time(X509_STORE_CTX *ctx, X509 *x)
+int x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int quiet)
 	{
 	time_t *ptime;
 	int i;
@@ -1537,6 +1710,8 @@ static int check_cert_time(X509_STORE_CTX *ctx, X509 *x)
 	i=X509_cmp_time(X509_get_notBefore(x), ptime);
 	if (i == 0)
 		{
+		if (quiet)
+			return 0;
 		ctx->error=X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD;
 		ctx->current_cert=x;
 		if (!ctx->verify_cb(0, ctx))
@@ -1545,6 +1720,8 @@ static int check_cert_time(X509_STORE_CTX *ctx, X509 *x)
 
 	if (i > 0)
 		{
+		if (quiet)
+			return 0;
 		ctx->error=X509_V_ERR_CERT_NOT_YET_VALID;
 		ctx->current_cert=x;
 		if (!ctx->verify_cb(0, ctx))
@@ -1554,6 +1731,8 @@ static int check_cert_time(X509_STORE_CTX *ctx, X509 *x)
 	i=X509_cmp_time(X509_get_notAfter(x), ptime);
 	if (i == 0)
 		{
+		if (quiet)
+			return 0;
 		ctx->error=X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD;
 		ctx->current_cert=x;
 		if (!ctx->verify_cb(0, ctx))
@@ -1562,6 +1741,8 @@ static int check_cert_time(X509_STORE_CTX *ctx, X509 *x)
 
 	if (i < 0)
 		{
+		if (quiet)
+			return 0;
 		ctx->error=X509_V_ERR_CERT_HAS_EXPIRED;
 		ctx->current_cert=x;
 		if (!ctx->verify_cb(0, ctx))
@@ -1589,6 +1770,11 @@ static int internal_verify(X509_STORE_CTX *ctx)
 		xs=xi;
 	else
 		{
+		if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN)
+			{
+			xs = xi;
+			goto check_cert;
+			}
 		if (n <= 0)
 			{
 			ctx->error=X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE;
@@ -1608,7 +1794,12 @@ static int internal_verify(X509_STORE_CTX *ctx)
 	while (n >= 0)
 		{
 		ctx->error_depth=n;
-		if (!xs->valid)
+
+		/* 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)
 				{
@@ -1618,13 +1809,6 @@ static int internal_verify(X509_STORE_CTX *ctx)
 				if (!ok) goto end;
 				}
 			else if (X509_verify(xs,pkey) <= 0)
-				/* XXX  For the final trusted self-signed cert,
-				 * this is a waste of time.  That check should
-				 * optional so that e.g. 'openssl x509' can be
-				 * used to detect invalid self-signatures, but
-				 * we don't verify again and again in SSL
-				 * handshakes and the like once the cert has
-				 * been declared trusted. */
 				{
 				ctx->error=X509_V_ERR_CERT_SIGNATURE_FAILURE;
 				ctx->current_cert=xs;
@@ -1641,7 +1825,8 @@ static int internal_verify(X509_STORE_CTX *ctx)
 
 		xs->valid = 1;
 
-		ok = check_cert_time(ctx, xs);
+		check_cert:
+		ok = x509_check_cert_time(ctx, xs, 0);
 		if (!ok)
 			goto end;
 
@@ -1723,10 +1908,11 @@ int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time)
 			offset= -offset;
 		}
 	atm.type=ctm->type;
+	atm.flags = 0;
 	atm.length=sizeof(buff2);
 	atm.data=(unsigned char *)buff2;
 
-	if (X509_time_adj(&atm,-offset*60, cmp_time) == NULL)
+	if (X509_time_adj(&atm, offset*60, cmp_time) == NULL)
 		return 0;
 
 	if (ctm->type == V_ASN1_UTCTIME)
@@ -1751,19 +1937,28 @@ 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)
+ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm)
+	{
+	return X509_time_adj_ex(s, 0, offset_sec, in_tm);
+	}
+
+ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s,
+				int offset_day, long offset_sec, 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);
+	if (s && !(s->flags & ASN1_STRING_FLAG_MSTRING))
+		{
+		if (s->type == V_ASN1_UTCTIME)
+			return ASN1_UTCTIME_adj(s,t, offset_day, offset_sec);
+		if (s->type == V_ASN1_GENERALIZEDTIME)
+			return ASN1_GENERALIZEDTIME_adj(s, t, offset_day,
+								offset_sec);
+		}
+	return ASN1_TIME_adj(s, t, offset_day, offset_sec);
 	}
 
 int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
@@ -1808,6 +2003,125 @@ int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
 	return 1;
 	}
 
+/* Make a delta CRL as the diff between two full CRLs */
+
+X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer,
+			EVP_PKEY *skey, const EVP_MD *md, unsigned int flags)
+	{
+	X509_CRL *crl = NULL;
+	int i;
+	STACK_OF(X509_REVOKED) *revs = NULL;
+	/* CRLs can't be delta already */
+	if (base->base_crl_number || newer->base_crl_number)
+			{
+			X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_ALREADY_DELTA);
+			return NULL;
+			}
+	/* Base and new CRL must have a CRL number */
+	if (!base->crl_number || !newer->crl_number)
+			{
+			X509err(X509_F_X509_CRL_DIFF, X509_R_NO_CRL_NUMBER);
+			return NULL;
+			}
+	/* Issuer names must match */
+	if (X509_NAME_cmp(X509_CRL_get_issuer(base),
+				X509_CRL_get_issuer(newer)))
+			{
+			X509err(X509_F_X509_CRL_DIFF, X509_R_ISSUER_MISMATCH);
+			return NULL;
+			}
+	/* AKID and IDP must match */
+	if (!crl_extension_match(base, newer, NID_authority_key_identifier))
+			{
+			X509err(X509_F_X509_CRL_DIFF, X509_R_AKID_MISMATCH);
+			return NULL;
+			}
+	if (!crl_extension_match(base, newer, NID_issuing_distribution_point))
+			{
+			X509err(X509_F_X509_CRL_DIFF, X509_R_IDP_MISMATCH);
+			return NULL;
+			}
+	/* Newer CRL number must exceed full CRL number */
+	if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0)
+			{
+			X509err(X509_F_X509_CRL_DIFF, X509_R_NEWER_CRL_NOT_NEWER);
+			return NULL;
+			}
+	/* CRLs must verify */
+	if (skey && (X509_CRL_verify(base, skey) <= 0 ||
+			X509_CRL_verify(newer, skey) <= 0))
+		{
+		X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_VERIFY_FAILURE);
+		return NULL;
+		}
+	/* Create new CRL */
+	crl = X509_CRL_new();
+	if (!crl || !X509_CRL_set_version(crl, 1))
+		goto memerr;
+	/* Set issuer name */
+	if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer)))
+		goto memerr;
+
+	if (!X509_CRL_set_lastUpdate(crl, X509_CRL_get_lastUpdate(newer)))
+		goto memerr;
+	if (!X509_CRL_set_nextUpdate(crl, X509_CRL_get_nextUpdate(newer)))
+		goto memerr;
+
+	/* Set base CRL number: must be critical */
+
+	if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0))
+		goto memerr;
+
+	/* Copy extensions across from newest CRL to delta: this will set
+	 * CRL number to correct value too.
+	 */
+
+	for (i = 0; i < X509_CRL_get_ext_count(newer); i++)
+		{
+		X509_EXTENSION *ext;
+		ext = X509_CRL_get_ext(newer, i);
+		if (!X509_CRL_add_ext(crl, ext, -1))
+			goto memerr;
+		}
+
+	/* Go through revoked entries, copying as needed */
+
+	revs = X509_CRL_get_REVOKED(newer);
+
+	for (i = 0; i < sk_X509_REVOKED_num(revs); i++)
+		{
+		X509_REVOKED *rvn, *rvtmp;
+		rvn = sk_X509_REVOKED_value(revs, i);
+		/* Add only if not also in base.
+		 * TODO: need something cleverer here for some more complex
+		 * CRLs covering multiple CAs.
+		 */
+		if (!X509_CRL_get0_by_serial(base, &rvtmp, rvn->serialNumber))
+			{
+			rvtmp = X509_REVOKED_dup(rvn);
+			if (!rvtmp)
+				goto memerr;
+			if (!X509_CRL_add0_revoked(crl, rvtmp))
+				{
+				X509_REVOKED_free(rvtmp);
+				goto memerr;
+				}
+			}
+		}
+	/* TODO: optionally prune deleted entries */
+
+	if (skey && md && !X509_CRL_sign(crl, skey, md))
+		goto memerr;
+	
+	return crl;
+
+	memerr:
+	X509err(X509_F_X509_CRL_DIFF, ERR_R_MALLOC_FAILURE);
+	if (crl)
+		X509_CRL_free(crl);
+	return NULL;
+	}
+
 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)
 	{
@@ -1854,16 +2168,24 @@ STACK_OF(X509) *X509_STORE_CTX_get_chain(X509_STORE_CTX *ctx)
 
 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;
+	if (!ctx->chain)
+		return NULL;
+	return X509_chain_up_ref(ctx->chain);
+	}
+
+X509 *X509_STORE_CTX_get0_current_issuer(X509_STORE_CTX *ctx)
+	{
+	return ctx->current_issuer;
+	}
+
+X509_CRL *X509_STORE_CTX_get0_current_crl(X509_STORE_CTX *ctx)
+	{
+	return ctx->current_crl;
+	}
+
+X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(X509_STORE_CTX *ctx)
+	{
+	return ctx->parent;
 	}
 
 void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x)
@@ -1986,6 +2308,9 @@ int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
 	ctx->error_depth=0;
 	ctx->current_cert=NULL;
 	ctx->current_issuer=NULL;
+	ctx->current_crl=NULL;
+	ctx->current_crl_score=0;
+	ctx->current_reasons=0;
 	ctx->tree = NULL;
 	ctx->parent = NULL;
 
@@ -2005,7 +2330,7 @@ int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
 	if (store)
 		ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param);
 	else
-		ctx->param->flags |= X509_VP_FLAG_DEFAULT|X509_VP_FLAG_ONCE;
+		ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT|X509_VP_FLAG_ONCE;
 
 	if (store)
 		{