Handle zero-distance rotates correctly

2 files changed, 8 insertions, 8 deletions

diff --git a/crypto/src/util/Integers.cs b/crypto/src/util/Integers.cs

index b0c899500..75ba566e3 100644
--- a/crypto/src/util/Integers.cs
+++ b/crypto/src/util/Integers.cs
@@ -111,7 +111,7 @@ namespace Org.BouncyCastle.Utilities
 #if NETCOREAPP3_0_OR_GREATER
             return (int)BitOperations.RotateLeft((uint)i, distance);
 #else
-            return (i << distance) ^ (int)((uint)i >> -distance);
+            return (i << distance) | (int)((uint)i >> -distance);
 #endif
         }
 
@@ -121,7 +121,7 @@ namespace Org.BouncyCastle.Utilities
 #if NETCOREAPP3_0_OR_GREATER
             return BitOperations.RotateLeft(i, distance);
 #else
-            return (i << distance) ^ (i >> -distance);
+            return (i << distance) | (i >> -distance);
 #endif
         }
 
@@ -130,7 +130,7 @@ namespace Org.BouncyCastle.Utilities
 #if NETCOREAPP3_0_OR_GREATER
             return (int)BitOperations.RotateRight((uint)i, distance);
 #else
-            return (int)((uint)i >> distance) ^ (i << -distance);
+            return (int)((uint)i >> distance) | (i << -distance);
 #endif
         }
 
@@ -140,7 +140,7 @@ namespace Org.BouncyCastle.Utilities
 #if NETCOREAPP3_0_OR_GREATER
             return BitOperations.RotateRight(i, distance);
 #else
-            return (i >> distance) ^ (i << -distance);
+            return (i >> distance) | (i << -distance);
 #endif
         }
     }
diff --git a/crypto/src/util/Longs.cs b/crypto/src/util/Longs.cs

index 0bb35de25..9e34dab99 100644
--- a/crypto/src/util/Longs.cs
+++ b/crypto/src/util/Longs.cs
@@ -112,7 +112,7 @@ namespace Org.BouncyCastle.Utilities
 #if NETCOREAPP3_0_OR_GREATER
             return (long)BitOperations.RotateLeft((ulong)i, distance);
 #else
-            return (i << distance) ^ (long)((ulong)i >> -distance);
+            return (i << distance) | (long)((ulong)i >> -distance);
 #endif
         }
 
@@ -122,7 +122,7 @@ namespace Org.BouncyCastle.Utilities
 #if NETCOREAPP3_0_OR_GREATER
             return BitOperations.RotateLeft(i, distance);
 #else
-            return (i << distance) ^ (i >> -distance);
+            return (i << distance) | (i >> -distance);
 #endif
         }
 
@@ -131,7 +131,7 @@ namespace Org.BouncyCastle.Utilities
 #if NETCOREAPP3_0_OR_GREATER
             return (long)BitOperations.RotateRight((ulong)i, distance);
 #else
-            return (long)((ulong)i >> distance) ^ (i << -distance);
+            return (long)((ulong)i >> distance) | (i << -distance);
 #endif
         }
 
@@ -141,7 +141,7 @@ namespace Org.BouncyCastle.Utilities
 #if NETCOREAPP3_0_OR_GREATER
             return BitOperations.RotateRight(i, distance);
 #else
-            return (i >> distance) ^ (i << -distance);
+            return (i >> distance) | (i << -distance);
 #endif
         }
     }