verify RFC3779 IP address blocks along X.509 certificate trust chain

src/charon/credentials/credential_manager.c

@@ -937,6 +937,60 @@ static cert_validation_t check_crl(private_credential_manager_t *this,
 	return valid;
 }
 
+/**
+ * check a certificate for optional IP address block constraints
+ */
+static bool check_ip_addr_block_constraints(x509_t *subject, x509_t *issuer)
+{
+	bool subject_constraint = subject->get_flags(subject) & X509_IP_ADDR_BLOCKS;
+	bool issuer_constraint = issuer->get_flags(issuer) & X509_IP_ADDR_BLOCKS;
+	bool contained = TRUE;
+
+	enumerator_t *subject_enumerator, *issuer_enumerator;
+	traffic_selector_t *subject_ts, *issuer_ts;
+
+	if (!subject_constraint && !issuer_constraint)
+	{
+		return TRUE;		
+	}
+	if (!subject_constraint)
+	{
+		DBG1(DBG_CFG, "subject certficate lacks ipAddrBlocks extension");
+		return FALSE;
+	}
+	if (!issuer_constraint)
+	{
+		DBG1(DBG_CFG, "issuer certficate lacks ipAddrBlocks extension");
+		return FALSE;		
+	}
+	subject_enumerator = subject->create_ipAddrBlock_enumerator(subject);
+	while (subject_enumerator->enumerate(subject_enumerator, &subject_ts))
+	{
+		contained = FALSE;
+
+		issuer_enumerator = issuer->create_ipAddrBlock_enumerator(issuer);
+		while (issuer_enumerator->enumerate(issuer_enumerator, &issuer_ts))
+		{
+			if (subject_ts->is_contained_in(subject_ts, issuer_ts))
+			{
+				DBG2(DBG_CFG, "  subject address block %R is contained in "
+							  "issuer address block %R", subject_ts, issuer_ts);
+				contained = TRUE;
+				break;
+			}
+		}
+		issuer_enumerator->destroy(issuer_enumerator);
+		if (!contained)
+		{
+			DBG1(DBG_CFG, "subject address block %R is not contained in any "
+						  "issuer address block", subject_ts);
+			break;
+		}
+	}
+	subject_enumerator->destroy(subject_enumerator);
+	return contained;	
+}
+
 /**
  * check a certificate for its lifetime
  */
@@ -961,6 +1015,10 @@ static bool check_certificate(private_credential_manager_t *this,
 	if (issuer->get_type(issuer) == CERT_X509 &&
 		subject->get_type(subject) == CERT_X509)
 	{
+		if (!check_ip_addr_block_constraints((x509_t*)subject, (x509_t*)issuer))
+		{
+			return FALSE;
+		}
 		if (ocsp || crl)
 		{
 			DBG1(DBG_CFG, "checking certificate status of \"%Y\"",