Use correctly and validate certificate ECDSA signature hash algorithm

mrsuciu · Dec 16, 2024 · d1c8751 · d1c8751
1 parent 0777bbd
commit d1c8751
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Showing 2 changed files with 27 additions and 5 deletions.
diff --git a/Libraries/Opc.Ua.Configuration/ApplicationInstance.cs b/Libraries/Opc.Ua.Configuration/ApplicationInstance.cs
@@ -2,7 +2,7 @@
  * Copyright (c) 2005-2021 The OPC Foundation, Inc. All rights reserved.
  *
  * OPC Foundation MIT License 1.00
- * 
+ *
  * Permission is hereby granted, free of charge, to any person
  * obtaining a copy of this software and associated documentation
  * files (the "Software"), to deal in the Software without
@@ -11,7 +11,7 @@
  * copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following
  * conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be
  * included in all copies or substantial portions of the Software.
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
@@ -499,7 +499,7 @@ public async Task<bool> CheckApplicationInstanceCertificates(
 
         #region Private Methods
         /// <summary>
-        /// 
+        ///
         /// </summary>
         /// <param name="id"></param>
         /// <param name="silent"></param>
@@ -715,7 +715,7 @@ await configuration.CertificateValidator.ValidateAsync(
                 configuration.CertificateValidator.CertificateValidation -= certValidator.OnCertificateValidation;
             }
 
-            // check key size 
+            // check key size
             int keySize = X509Utils.GetPublicKeySize(certificate);
             if (minimumKeySize > keySize)
             {
@@ -911,6 +911,7 @@ private static async Task<X509Certificate2> CreateApplicationInstanceCertificate
                 throw new ServiceResultException(StatusCodes.BadConfigurationError, "The Ecc certificate type is not supported.");
 #else
                 ECCurve curve = default(ECCurve);
+                HashAlgorithmName hashAlgorithm = HashAlgorithmName.SHA256;
                 if (id.CertificateType == ObjectTypeIds.EccApplicationCertificateType ||
                     id.CertificateType == ObjectTypeIds.EccNistP256ApplicationCertificateType)
                 {
@@ -919,6 +920,7 @@ private static async Task<X509Certificate2> CreateApplicationInstanceCertificate
                 else if (id.CertificateType == ObjectTypeIds.EccNistP384ApplicationCertificateType)
                 {
                     curve = ECCurve.NamedCurves.nistP384;
+                    hashAlgorithm = HashAlgorithmName.SHA384;
                 }
                 else if (id.CertificateType == ObjectTypeIds.EccBrainpoolP256r1ApplicationCertificateType)
                 {
@@ -927,6 +929,7 @@ private static async Task<X509Certificate2> CreateApplicationInstanceCertificate
                 else if (id.CertificateType == ObjectTypeIds.EccBrainpoolP384r1ApplicationCertificateType)
                 {
                     curve = ECCurve.NamedCurves.brainpoolP384r1;
+                    hashAlgorithm = HashAlgorithmName.SHA384;
                 }
 #if CURVE25519
                 else if (id.CertificateType == ObjectTypeIds.EccCurve25519ApplicationCertificateType)
@@ -944,6 +947,7 @@ private static async Task<X509Certificate2> CreateApplicationInstanceCertificate
                 }
 
                 id.Certificate = builder
+                    .SetHashAlgorithm(hashAlgorithm)
                     .SetECCurve(curve)
                     .CreateForECDsa();
 

diff --git a/Stack/Opc.Ua.Core/Security/Certificates/CertificateValidator.cs b/Stack/Opc.Ua.Core/Security/Certificates/CertificateValidator.cs
@@ -30,7 +30,7 @@ namespace Opc.Ua
     /// </summary>
     public class CertificateValidator : ICertificateValidator
     {
-        // default number of rejected certificates for history 
+        // default number of rejected certificates for history
         const int kDefaultMaxRejectedCertificates = 5;
 
         #region Constructors
@@ -1414,6 +1414,24 @@ protected virtual async Task InternalValidateAsync(X509Certificate2Collection ce
                     null, null, "SHA1 signed certificates are not trusted.", null, sresult);
             }
 
+            // check if certificate signature algorithm length is sufficient
+            if (isECDsaSignature)
+            {
+                int publicKeySize = X509Utils.GetPublicKeySize(certificate);
+                bool isInvalid = (certificate.SignatureAlgorithm.Value == Oids.ECDsaWithSha256 &&
+                                  publicKeySize < 256) ||
+                                 (certificate.SignatureAlgorithm.Value == Oids.ECDsaWithSha384 &&
+                                  publicKeySize < 384) ||
+                                 (certificate.SignatureAlgorithm.Value == Oids.ECDsaWithSha512 &&
+                                  publicKeySize < 512);
+
+                if (isInvalid)
+                {
+                    sresult = new ServiceResult(StatusCodes.BadCertificatePolicyCheckFailed,
+                        null, null, "Certificate doesn't meet minimum key length requirement.", null, sresult);
+                }
+            }
+
             if (!isECDsaSignature)
             {
                 int keySize = X509Utils.GetRSAPublicKeySize(certificate);