From 425104bf259c04c971c67ff2fcd6da3df02167f1 Mon Sep 17 00:00:00 2001
From: Peter Dettman <peter.dettman@bouncycastle.org>
Date: Mon, 28 Mar 2022 19:17:21 +0700
Subject: Improve IsSupportedCipherSuite

---
 crypto/src/tls/TlsUtilities.cs | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

(limited to 'crypto/src')

diff --git a/crypto/src/tls/TlsUtilities.cs b/crypto/src/tls/TlsUtilities.cs
index 1d9759bca..05d38c59c 100644
--- a/crypto/src/tls/TlsUtilities.cs
+++ b/crypto/src/tls/TlsUtilities.cs
@@ -4146,9 +4146,22 @@ namespace Org.BouncyCastle.Tls
 
         public static bool IsSupportedCipherSuite(TlsCrypto crypto, int cipherSuite)
         {
-            return IsSupportedKeyExchange(crypto, GetKeyExchangeAlgorithm(cipherSuite))
-                && crypto.HasEncryptionAlgorithm(GetEncryptionAlgorithm(cipherSuite))
-                && crypto.HasMacAlgorithm(GetMacAlgorithm(cipherSuite));
+            int keyExchangeAlgorithm = GetKeyExchangeAlgorithm(cipherSuite);
+            if (!IsSupportedKeyExchange(crypto, keyExchangeAlgorithm))
+                return false;
+
+            int encryptionAlgorithm = GetEncryptionAlgorithm(cipherSuite);
+            if (encryptionAlgorithm < 0 || !crypto.HasEncryptionAlgorithm(encryptionAlgorithm))
+                return false;
+
+            int macAlgorithm = GetMacAlgorithm(cipherSuite);
+            if (macAlgorithm != MacAlgorithm.cls_null)
+            {
+                if (macAlgorithm < 0 || !crypto.HasMacAlgorithm(macAlgorithm))
+                    return false;
+            }
+
+            return true;
         }
 
         public static bool IsSupportedKeyExchange(TlsCrypto crypto, int keyExchangeAlgorithm)
-- 
cgit 1.5.1