rename STRUCTURED_IV to UNIQUE_IV. assert correct cipher direction

git-svn-id: svn://svn.code.sf.net/p/cryptopp/code/trunk/c5@311 57ff6487-cd31-0410-9ec3-f628ee90f5f0

1 files changed, 1 insertions, 0 deletions

diff --git a/modes.cpp b/modes.cpp
index 295fc34..b51afe9 100644
--- a/modes.cpp
+++ b/modes.cpp
@@ -61,6 +61,7 @@ inline void CTR_ModePolicy::ProcessMultipleBlocks(byte *output, const byte *inpu
 
 void CTR_ModePolicy::OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount)
 {
+	assert(m_cipher->IsForwardTransformation());	// CTR mode needs the "encrypt" direction of the underlying block cipher, even to decrypt
 	unsigned int maxBlocks = m_cipher->OptimalNumberOfParallelBlocks();
 	if (maxBlocks == 1)
 	{