From 834e1f702bf33e3ba8677912f7a29730acb817aa Mon Sep 17 00:00:00 2001
From: Stephen Toub <stoub@microsoft.com>
Date: Wed, 26 Jul 2023 13:19:33 -0400
Subject: [PATCH] Use one-shot hash APIs in a couple of places (#2159)

---
 .../SignedHttpRequestHandler.cs                       | 11 +++++++++--
 src/Microsoft.IdentityModel.Tokens/Utility.cs         |  8 +++++++-
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/Microsoft.IdentityModel.Protocols.SignedHttpRequest/SignedHttpRequestHandler.cs b/src/Microsoft.IdentityModel.Protocols.SignedHttpRequest/SignedHttpRequestHandler.cs
index 5f5a4962ff..768268b16d 100644
--- a/src/Microsoft.IdentityModel.Protocols.SignedHttpRequest/SignedHttpRequestHandler.cs
+++ b/src/Microsoft.IdentityModel.Protocols.SignedHttpRequest/SignedHttpRequestHandler.cs
@@ -1213,11 +1213,18 @@ private static string CalculateBase64UrlEncodedHash(string data)
 
         private static string CalculateBase64UrlEncodedHash(byte[] bytes)
         {
+            byte[] hashedBytes;
+
+#if NET6_0_OR_GREATER
+            hashedBytes = SHA256.HashData(bytes);
+#else
             using (var hash = SHA256.Create())
             {
-                var hashedBytes = hash.ComputeHash(bytes);
-                return Base64UrlEncoder.Encode(hashedBytes);
+                hashedBytes = hash.ComputeHash(bytes);
             }
+#endif
+
+            return Base64UrlEncoder.Encode(hashedBytes);
         }
 
         /// <summary>
diff --git a/src/Microsoft.IdentityModel.Tokens/Utility.cs b/src/Microsoft.IdentityModel.Tokens/Utility.cs
index b9f53cf9b8..1723a5a34d 100644
--- a/src/Microsoft.IdentityModel.Tokens/Utility.cs
+++ b/src/Microsoft.IdentityModel.Tokens/Utility.cs
@@ -251,10 +251,16 @@ internal static void Zero(byte[] byteArray)
 
         internal static byte[] GenerateSha256Hash(string input)
         {
+            byte[] bytes = Encoding.UTF8.GetBytes(input);
+
+#if NET6_0_OR_GREATER
+            return SHA256.HashData(bytes);
+#else
             using (var hash = SHA256.Create())
             {
-                return hash.ComputeHash(Encoding.UTF8.GetBytes(input));
+                return hash.ComputeHash(bytes);
             }
+#endif
         }
     }
 }