Improve documentation of CBC functions
diff --git a/include/polarssl/blowfish.h b/include/polarssl/blowfish.h
index e1d25cf..f91b38d 100644
--- a/include/polarssl/blowfish.h
+++ b/include/polarssl/blowfish.h
@@ -114,6 +114,14 @@
* Length should be a multiple of the block
* size (8 bytes)
*
+ * \note Upon exit, the content of the IV is updated so that you can
+ * call the function same function again on the following
+ * block(s) of data and get the same result as if it was
+ * encrypted in one call. This allows a "streaming" usage.
+ * If on the other hand you need to retain the contents of the
+ * IV, you should either save it manually or use the cipher
+ * module instead.
+ *
* \param ctx Blowfish context
* \param mode BLOWFISH_ENCRYPT or BLOWFISH_DECRYPT
* \param length length of the input data
@@ -136,6 +144,14 @@
/**
* \brief Blowfish CFB buffer encryption/decryption.
*
+ * \note Upon exit, the content of the IV is updated so that you can
+ * call the function same function again on the following
+ * block(s) of data and get the same result as if it was
+ * encrypted in one call. This allows a "streaming" usage.
+ * If on the other hand you need to retain the contents of the
+ * IV, you should either save it manually or use the cipher
+ * module instead.
+ *
* \param ctx Blowfish context
* \param mode BLOWFISH_ENCRYPT or BLOWFISH_DECRYPT
* \param length length of the input data