Initial indirect CRL support.

CHANGES

@@ -4,6 +4,14 @@
 
  Changes between 0.9.8i and 0.9.9  [xx XXX xxxx]
 
+  *) Initial indirect CRL support. Currently only supported in the CRLs
+     passed directly and not via lookup. Process certificate issuer
+     CRL entry extension and lookup CRL entries by bother issuer name
+     and serial number. Check and proces CRL issuer entry in IDP extension.
+
+     This work was sponsored by Google.
+     [Steve Henson]
+
   *) Add support for distinct certificate and CRL paths. The CRL issuer
      certificate is validated separately in this case. Only enabled if
      an extended CRL support flag is set: this flag will enable additional

crypto/asn1/asn1_locl.h

@@ -128,6 +128,7 @@ struct x509_crl_method_st
 	int flags;
 	int (*crl_init)(X509_CRL *crl);
 	int (*crl_free)(X509_CRL *crl);
-	int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret, ASN1_INTEGER *ser);
+	int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret,
+				ASN1_INTEGER *ser, X509_NAME *issuer);
 	int (*crl_verify)(X509_CRL *crl, EVP_PKEY *pk);
 	};

crypto/asn1/x_crl.c

@@ -75,7 +75,7 @@ ASN1_SEQUENCE(X509_REVOKED) = {
 
 static int def_crl_verify(X509_CRL *crl, EVP_PKEY *r);
 static int def_crl_lookup(X509_CRL *crl,
-		X509_REVOKED **ret, ASN1_INTEGER *serial);
+		X509_REVOKED **ret, ASN1_INTEGER *serial, X509_NAME *issuer);
 
 static X509_CRL_METHOD int_crl_meth =
 	{
@@ -119,6 +119,72 @@ ASN1_SEQUENCE_enc(X509_CRL_INFO, enc, crl_inf_cb) = {
 	ASN1_EXP_SEQUENCE_OF_OPT(X509_CRL_INFO, extensions, X509_EXTENSION, 0)
 } ASN1_SEQUENCE_END_enc(X509_CRL_INFO, X509_CRL_INFO)
 
+/* Set CRL entry issuer according to CRL certificate issuer extension.
+ * Check for unhandled critical CRL entry extensions.
+ */
+
+static int crl_set_issuers(X509_CRL *crl)
+	{
+
+	int i, j;
+	GENERAL_NAMES *gens, *gtmp;
+	STACK_OF(X509_REVOKED) *revoked;
+
+	revoked = X509_CRL_get_REVOKED(crl);
+
+	gens = NULL;
+	for (i = 0; i < sk_X509_REVOKED_num(revoked); i++)
+		{
+		X509_REVOKED *rev = sk_X509_REVOKED_value(revoked, i);
+		STACK_OF(X509_EXTENSION) *exts;
+		X509_EXTENSION *ext;
+		gtmp = X509_REVOKED_get_ext_d2i(rev, 
+						NID_certificate_issuer,
+						&j, NULL);
+		if (!gtmp && (j != -1))
+			{
+			crl->flags |= EXFLAG_INVALID;
+			return 1;
+			}
+
+		if (gtmp)
+			{
+			gens = gtmp;
+			if (!crl->issuers)
+				{
+				crl->issuers = sk_GENERAL_NAMES_new_null();
+				if (!crl->issuers)
+					return 0;
+				}
+			if (!sk_GENERAL_NAMES_push(crl->issuers, gtmp))
+				return 0;
+			}
+		rev->issuer = gens;
+
+		/* Check for critical CRL entry extensions */
+
+		exts = rev->extensions;
+
+		for (j = 0; j < sk_X509_EXTENSION_num(exts); j++)
+			{
+			ext = sk_X509_EXTENSION_value(exts, j);
+			if (ext->critical > 0)
+				{
+				if (OBJ_obj2nid(ext->object) ==
+					NID_certificate_issuer)
+					continue;
+				crl->flags |= EXFLAG_CRITICAL;
+				break;
+				}
+			}
+
+
+		}
+
+	return 1;
+
+	}
+
 /* The X509_CRL structure needs a bit of customisation. Cache some extensions
  * and hash of the whole CRL.
  */
@@ -139,6 +205,7 @@ static int crl_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
 		crl->idp_flags = 0;
 		crl->meth = default_crl_method;
 		crl->meth_data = NULL;
+		crl->issuers = NULL;
 		break;
 
 		case ASN1_OP_D2I_POST:
@@ -176,6 +243,11 @@ static int crl_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
 				break;
 				}
 			}
+
+
+		if (!crl_set_issuers(crl))
+			return 0;
+
 		if (crl->meth->crl_init)
 			{
 			if (crl->meth->crl_init(crl) == 0)
@@ -193,6 +265,7 @@ static int crl_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
 			AUTHORITY_KEYID_free(crl->akid);
 		if (crl->idp)
 			ISSUING_DIST_POINT_free(crl->idp);
+		sk_GENERAL_NAMES_pop_free(crl->issuers, GENERAL_NAMES_free);
 		break;
 		}
 	return 1;
@@ -284,7 +357,16 @@ int X509_CRL_get0_by_serial(X509_CRL *crl,
 		X509_REVOKED **ret, ASN1_INTEGER *serial)
 	{
 	if (crl->meth->crl_lookup)
-		return crl->meth->crl_lookup(crl, ret, serial);
+		return crl->meth->crl_lookup(crl, ret, serial, NULL);
+	return 0;
+	}
+
+int X509_CRL_get0_by_cert(X509_CRL *crl, X509_REVOKED **ret, X509 *x)
+	{
+	if (crl->meth->crl_lookup)
+		return crl->meth->crl_lookup(crl, ret,
+						X509_get_serialNumber(x),
+						X509_get_issuer_name(x));
 	return 0;
 	}
 
@@ -294,10 +376,39 @@ static int def_crl_verify(X509_CRL *crl, EVP_PKEY *r)
 		crl->sig_alg, crl->signature,crl->crl,r));
 	}
 
+static int crl_revoked_issuer_match(X509_CRL *crl, X509_NAME *nm,
+						X509_REVOKED *rev)
+	{
+	int i;
+
+	if (!rev->issuer)
+		{
+		if (!nm)
+			return 1;
+		if (!X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))
+			return 1;
+		return 0;
+		}
+
+	if (!nm)
+		nm = X509_CRL_get_issuer(crl);
+
+	for (i = 0; i < sk_GENERAL_NAME_num(rev->issuer); i++)
+		{
+		GENERAL_NAME *gen = sk_GENERAL_NAME_value(rev->issuer, i);
+		if (gen->type != GEN_DIRNAME)
+			continue;
+		if (!X509_NAME_cmp(nm, gen->d.directoryName))
+			return 1;
+		}
+	return 0;
+
+	}
+
 static int def_crl_lookup(X509_CRL *crl,
-		X509_REVOKED **ret, ASN1_INTEGER *serial)
+		X509_REVOKED **ret, ASN1_INTEGER *serial, X509_NAME *issuer)
 	{
-	X509_REVOKED rtmp;
+	X509_REVOKED rtmp, *rev;
 	int idx;
 	rtmp.serialNumber = serial;
 	/* Sort revoked into serial number order if not already sorted.
@@ -310,14 +421,20 @@ static int def_crl_lookup(X509_CRL *crl,
 		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)
+	if(idx < 0)
+		return 0;
+	/* Need to look for matching name */
+	for(;idx < sk_X509_REVOKED_num(crl->crl->revoked); idx++)
 		{
-		if (ret)
-			*ret = sk_X509_REVOKED_value(crl->crl->revoked, idx);
-		return 1;
+		rev = sk_X509_REVOKED_value(crl->crl->revoked, idx);
+		if (ASN1_INTEGER_cmp(rev->serialNumber, serial))
+			return 0;
+		if (crl_revoked_issuer_match(crl, issuer, rev))
+			{
+			if (ret)
+				*ret = rev;
+			return 1;
+			}
 		}
 	return 0;
 	}
@@ -333,7 +450,8 @@ void X509_CRL_set_default_method(const X509_CRL_METHOD *meth)
 X509_CRL_METHOD *X509_CRL_METHOD_new(
 	int (*crl_init)(X509_CRL *crl),
 	int (*crl_free)(X509_CRL *crl),
-	int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret, ASN1_INTEGER *ser),
+	int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret,
+				ASN1_INTEGER *ser, X509_NAME *issuer),
 	int (*crl_verify)(X509_CRL *crl, EVP_PKEY *pk))
 	{
 	X509_CRL_METHOD *m;

crypto/x509/x509.h

@@ -434,6 +434,8 @@ struct x509_revoked_st
 	ASN1_INTEGER *serialNumber;
 	ASN1_TIME *revocationDate;
 	STACK_OF(X509_EXTENSION) /* optional */ *extensions;
+	/* Set up if indirect CRL */
+	STACK_OF(GENERAL_NAME) *issuer;
 	int sequence; /* load sequence */
 	};
 
@@ -469,6 +471,7 @@ struct X509_crl_st
 #ifndef OPENSSL_NO_SHA
 	unsigned char sha1_hash[SHA_DIGEST_LENGTH];
 #endif
+	STACK_OF(GENERAL_NAMES) *issuers;
 	const X509_CRL_METHOD *meth;
 	void *meth_data;
 	} /* X509_CRL */;
@@ -617,7 +620,8 @@ void X509_CRL_set_default_method(const X509_CRL_METHOD *meth);
 X509_CRL_METHOD *X509_CRL_METHOD_new(
 	int (*crl_init)(X509_CRL *crl),
 	int (*crl_free)(X509_CRL *crl),
-	int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret, ASN1_INTEGER *ser),
+	int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret,
+				ASN1_INTEGER *ser, X509_NAME *issuer),
 	int (*crl_verify)(X509_CRL *crl, EVP_PKEY *pk));
 void X509_CRL_METHOD_free(X509_CRL_METHOD *m);
 
@@ -847,6 +851,7 @@ DECLARE_ASN1_FUNCTIONS(X509_CRL)
 int X509_CRL_add0_revoked(X509_CRL *crl, X509_REVOKED *rev);
 int X509_CRL_get0_by_serial(X509_CRL *crl,
 		X509_REVOKED **ret, ASN1_INTEGER *serial);
+int X509_CRL_get0_by_cert(X509_CRL *crl, X509_REVOKED **ret, X509 *x);
 
 X509_PKEY *	X509_PKEY_new(void );
 void		X509_PKEY_free(X509_PKEY *a);

crypto/x509/x509_vfy.c

@@ -80,7 +80,7 @@ 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 crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer);
-static int idp_check_scope(X509 *x, X509_CRL *crl);
+static int idp_check_scope(X509 *x, X509_CRL *crl, int *pimatch);
 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x);
 static int check_crl_chain(X509_STORE_CTX *ctx,
 			STACK_OF(X509) *cert_path,
@@ -751,7 +751,7 @@ static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
 
 /* IDP flags which cause a CRL to be rejected */
 
-#define IDP_REJECT	(IDP_INVALID|IDP_INDIRECT|IDP_REASONS)
+#define IDP_REJECT	(IDP_INVALID|IDP_REASONS)
 
 static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
 			X509_NAME *nm, STACK_OF(X509_CRL) *crls)
@@ -761,11 +761,19 @@ static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
 	X509 *crl_issuer, *best_crl_issuer = NULL;
 	for (i = 0; i < sk_X509_CRL_num(crls); i++)
 		{
+		int imatch = 1;
 		crl_score = 0;
 		crl_issuer = NULL;
 		crl = sk_X509_CRL_value(crls, i);
 		if (nm && X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))
-			continue;
+			{
+			/* Issuer name does not match: could be indirect */
+			if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
+				continue;
+			if (!(crl->idp_flags & IDP_INDIRECT))
+				continue;
+			imatch = 0;
+			}
 		if (check_crl_time(ctx, crl, 0))
 			crl_score |= CRL_SCORE_TIME;
 
@@ -773,12 +781,16 @@ static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
 			{
 			if (crl->idp_flags & IDP_REJECT)
 				continue;
-			if (idp_check_scope(ctx->current_cert, crl))
+			if (idp_check_scope(ctx->current_cert, crl, &imatch))
 				crl_score |= CRL_SCORE_SCOPE;
 			}
 		else
 			crl_score |= CRL_SCORE_SCOPE;
 
+		/* If no issuer match at this point try next CRL */
+		if (!imatch)
+			continue;
+
 		if (crl_akid_check(ctx, crl, &crl_issuer))
 			crl_score |= CRL_SCORE_AKID;
 		/* If CRL matches criteria and issuer is not different use it */
@@ -809,6 +821,7 @@ static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
 static int crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer)
 	{
 	X509 *crl_issuer;
+	X509_NAME *cnm = X509_CRL_get_issuer(crl);
 	int cidx = ctx->error_depth;
 	int i;
 	if (!crl->akid)
@@ -818,25 +831,18 @@ static int crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer)
 	crl_issuer = sk_X509_value(ctx->chain, cidx);
 	if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK)
 		return 1;
-	/* If crl_issuer is self issued we may get a match further along the
-	 * chain.
-	 */
-	if (crl_issuer->ex_flags & EXFLAG_SI)
+	for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++)
 		{
-		for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++)
+		crl_issuer = sk_X509_value(ctx->chain, cidx);
+		if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
+			continue;
+		if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK)
 			{
-			crl_issuer = sk_X509_value(ctx->chain, cidx);
-			if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK)
-				{
-				*pissuer = crl_issuer;
-				return 1;
-				}
-			if (!(crl_issuer->ex_flags & EXFLAG_SI))
-				break;
+			*pissuer = crl_issuer;
+			return 1;
 			}
 		}
 
-
 	/* Anything else needs extended CRL support */
 
 	if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
@@ -845,7 +851,6 @@ static int crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer)
 	/* Otherwise the CRL issuer is not on the path. Look for it in the
 	 * set of untrusted certificates.
 	 */
-
 	for (i = 0; i < sk_X509_num(ctx->untrusted); i++)
 		{
 		crl_issuer = sk_X509_value(ctx->untrusted, i);
@@ -928,6 +933,7 @@ static int check_crl_chain(X509_STORE_CTX *ctx,
  * 1. Both are relative names and compare X509_NAME types.
  * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES.
  * 3. Both are full names and compare two GENERAL_NAMES.
+ * 4. One is NULL: automatic match.
  */
 
 
@@ -937,6 +943,8 @@ static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
 	GENERAL_NAMES *gens = NULL;
 	GENERAL_NAME *gena, *genb;
 	int i, j;
+	if (!a || !b)
+		return 1;
 	if (a->type == 1)
 		{
 		if (!a->dpname)
@@ -995,9 +1003,30 @@ static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
 
 	}
 
+static int idp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int *pimatch)
+	{
+	int i;
+	X509_NAME *nm = X509_CRL_get_issuer(crl);
+	/* If no CRLissuer return is successful iff don't need a match */
+	if (!dp->CRLissuer)
+		return *pimatch;
+	for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++)
+		{
+		GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
+		if (gen->type != GEN_DIRNAME)
+			continue;
+		if (!X509_NAME_cmp(gen->d.directoryName, nm))
+			{
+			*pimatch = 1;
+			return 1;
+			}
+		}
+	return 0;
+	}
+
 /* Check IDP name matches at least one CRLDP name */
 
-static int idp_check_scope(X509 *x, X509_CRL *crl)
+static int idp_check_scope(X509 *x, X509_CRL *crl, int *pimatch)
 	{
 	int i;
 	if (crl->idp_flags & IDP_ONLYATTR)
@@ -1012,18 +1041,19 @@ static int idp_check_scope(X509 *x, X509_CRL *crl)
 		if (crl->idp_flags & IDP_ONLYCA)
 			return 0;
 		}
-	if (!crl->idp->distpoint)
+	if (!crl->idp->distpoint && *pimatch)
 		return 1;
-	if (!x->crldp)
-		return 0;
 	for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
 		{
 		DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i);
 		/* We don't handle these at present */
-		if (dp->reasons || dp->CRLissuer)
+		if (dp->reasons)
 			continue;
 		if (idp_check_dp(dp->distpoint, crl->idp->distpoint))
-			return 1;
+			{
+			if (idp_check_crlissuer(dp, crl, pimatch))
+				return 1;
+			}
 		}
 	return 0;
 	}
@@ -1117,19 +1147,20 @@ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
 
 		if (crl->idp_flags & IDP_PRESENT)
 			{
+			int dmy = 1;
 			if (crl->idp_flags & IDP_INVALID)
 				{
 				ctx->error = X509_V_ERR_INVALID_EXTENSION;
 				ok = ctx->verify_cb(0, ctx);
 				if(!ok) goto err;
 				}
-			if (crl->idp_flags & (IDP_REASONS|IDP_INDIRECT))
+			if (crl->idp_flags & IDP_REASONS)
 				{
 				ctx->error = X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE;
 				ok = ctx->verify_cb(0, ctx);
 				if(!ok) goto err;
 				}
-			if (!idp_check_scope(ctx->current_cert, crl))
+			if (!idp_check_scope(ctx->current_cert, crl, &dmy))
 				{
 				ctx->error = X509_V_ERR_DIFFERENT_CRL_SCOPE;
 				ok = ctx->verify_cb(0, ctx);
@@ -1177,7 +1208,7 @@ static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
 	 * If found assume revoked: want something cleverer than
 	 * this to handle entry extensions in V2 CRLs.
 	 */
-	if (X509_CRL_get0_by_serial(crl, NULL, X509_get_serialNumber(x)) > 0)
+	if (X509_CRL_get0_by_cert(crl, NULL, x) > 0)
 		{
 		ctx->error = X509_V_ERR_CERT_REVOKED;
 		ok = ctx->verify_cb(0, ctx);