Make Stream_Cipher::set_iv() pure virtual

It provided a default implementation that only checked
that the length was correct, but ignored the actual data
and did not notify the caller, which seemed like a
rather odd behaviour.

The only implementation that used this default implementation,
RC4, now throws an exception.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/lib/prov/openssl/openssl_rc4.cpp b/src/lib/prov/openssl/openssl_rc4.cpp
index 070cdb14d..d6246e4ab 100644
--- a/src/lib/prov/openssl/openssl_rc4.cpp
+++ b/src/lib/prov/openssl/openssl_rc4.cpp
@@ -12,6 +12,7 @@
 #include <botan/internal/algo_registry.h>
 #include <botan/internal/openssl.h>
 #include <botan/parsing.h>
+#include <botan/exceptn.h>
 #include <openssl/rc4.h>
 
 namespace Botan {
@@ -46,6 +47,11 @@ class OpenSSL_RC4 : public StreamCipher
       explicit OpenSSL_RC4(size_t skip = 0) : m_skip(skip) { clear(); }
       ~OpenSSL_RC4() { clear(); }
 
+      void set_iv(const byte*, size_t) override
+         {
+         throw Exception("RC4 does not support an IV");
+         }
+
       void seek(u64bit) override
          {
          throw Exception("RC4 does not support seeking");