1 files changed, 5 insertions, 0 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/crypto/modes/CFBBlockCipher.java b/bcprov/src/main/java/org/bouncycastle/crypto/modes/CFBBlockCipher.java
index 6167d256..b11716f4 100644
--- a/bcprov/src/main/java/org/bouncycastle/crypto/modes/CFBBlockCipher.java
+++ b/bcprov/src/main/java/org/bouncycastle/crypto/modes/CFBBlockCipher.java
@@ -36,6 +36,11 @@ public class CFBBlockCipher
     {
         super(cipher);
 
+        if (bitBlockSize > (cipher.getBlockSize() * 8) || bitBlockSize < 8 || bitBlockSize % 8 != 0)
+        {
+            throw new IllegalArgumentException("CFB" + bitBlockSize + " not supported");
+        }
+
         this.cipher = cipher;
         this.blockSize = bitBlockSize / 8;