Add BSI variant of EMSA1, from InSiTo

4 files changed, 73 insertions, 0 deletions

diff --git a/src/pk_pad/emsa1/emsa1.h b/src/pk_pad/emsa1/emsa1.h
index 2de2d325e..8a15e2bfe 100644
--- a/src/pk_pad/emsa1/emsa1.h
+++ b/src/pk_pad/emsa1/emsa1.h
@@ -18,6 +18,8 @@ class BOTAN_DLL EMSA1 : public EMSA
    public:
       EMSA1(HashFunction* h) : hash(h) {}
       ~EMSA1() { delete hash; }
+   protected:
+      const HashFunction* hash_ptr() const { return hash; }
    private:
       void update(const byte[], u32bit);
       SecureVector<byte> raw_data();
diff --git a/src/pk_pad/emsa1_bsi/emsa1_bsi.cpp b/src/pk_pad/emsa1_bsi/emsa1_bsi.cpp
new file mode 100644
index 000000000..cc7868a1d
--- /dev/null
+++ b/src/pk_pad/emsa1_bsi/emsa1_bsi.cpp
@@ -0,0 +1,27 @@
+/*************************************************
+* EMSA1 BSI Source File                          *
+* (C) 1999-2008 Jack Lloyd                       *
+*     2008 Falko Strenzke, FlexSecure GmbH       *
+*************************************************/
+
+#include <botan/emsa1_bsi.h>
+
+namespace Botan {
+
+/*************************************************
+* EMSA1 BSI Encode Operation                     *
+*************************************************/
+SecureVector<byte> EMSA1_BSI::encoding_of(const MemoryRegion<byte>& msg,
+                                          u32bit output_bits,
+                                          RandomNumberGenerator&)
+   {
+   if(msg.size() != hash_ptr()->OUTPUT_LENGTH)
+      throw Encoding_Error("EMSA1_BSI::encoding_of: Invalid size for input");
+
+   if(8*msg.size() <= output_bits)
+      return msg;
+
+   throw Encoding_Error("EMSA1_BSI::encoding_of: max key input size exceeded");
+   }
+
+}
diff --git a/src/pk_pad/emsa1_bsi/emsa1_bsi.h b/src/pk_pad/emsa1_bsi/emsa1_bsi.h
new file mode 100644
index 000000000..0c0745bb0
--- /dev/null
+++ b/src/pk_pad/emsa1_bsi/emsa1_bsi.h
@@ -0,0 +1,30 @@
+/*************************************************
+* EMSA1 BSI Variant Header File                  *
+* (C) 1999-2008 Jack Lloyd                       *
+*     2007 FlexSecure GmbH                       *
+*************************************************/
+
+#ifndef BOTAN_EMSA1_BSI_H__
+#define BOTAN_EMSA1_BSI_H__
+
+#include <botan/emsa1.h>
+
+namespace Botan {
+
+/**
+EMSA1_BSI is a variant of EMSA1 specified by the BSI. It accepts only
+hash values which are less or equal than the maximum key length. The
+implementation comes from InSiTo
+*/
+class BOTAN_DLL EMSA1_BSI : public EMSA1
+   {
+   public:
+      EMSA1_BSI(HashFunction* hash) : EMSA1(hash) {}
+   private:
+      SecureVector<byte> encoding_of(const MemoryRegion<byte>&, u32bit,
+                                     RandomNumberGenerator& rng);
+   };
+
+}
+
+#endif
diff --git a/src/pk_pad/emsa1_bsi/info.txt b/src/pk_pad/emsa1_bsi/info.txt
new file mode 100644
index 000000000..8a8c46abb
--- /dev/null
+++ b/src/pk_pad/emsa1_bsi/info.txt
@@ -0,0 +1,14 @@
+realname "EMSA1 (BSI variant)"
+
+define EMSA1_BSI
+
+load_on auto
+
+<requires>
+emsa1
+</requires>
+
+<add>
+emsa1_bsi.h
+emsa1_bsi.cpp
+</add>