1 files changed, 97 insertions, 0 deletions
diff --git a/src/pk_pad/emsa3/emsa3.cpp b/src/pk_pad/emsa3/emsa3.cpp
new file mode 100644
index 000000000..60880d1aa
--- /dev/null
+++ b/src/pk_pad/emsa3/emsa3.cpp
@@ -0,0 +1,97 @@
+/*************************************************
+* EMSA3 Source File                              *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/emsa3.h>
+#include <botan/hash_id.h>
+#include <botan/lookup.h>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* EMSA3 Encode Operation                         *
+*************************************************/
+SecureVector<byte> emsa3_encoding(const MemoryRegion<byte>& msg,
+                                  u32bit output_bits,
+                                  const MemoryRegion<byte>& hash_id,
+                                  u32bit hash_size)
+   {
+   if(msg.size() != hash_size)
+      throw Encoding_Error("EMSA3::encoding_of: Bad input length");
+
+   u32bit output_length = output_bits / 8;
+   if(output_length < hash_id.size() + hash_size + 10)
+      throw Encoding_Error("EMSA3::pad: Output length is too small");
+
+   SecureVector<byte> T(output_length);
+   const u32bit P_LENGTH = output_length - hash_size - hash_id.size() - 2;
+
+   T[0] = 0x01;
+   set_mem(T+1, P_LENGTH, 0xFF);
+   T[P_LENGTH+1] = 0x00;
+   T.copy(P_LENGTH+2, hash_id, hash_id.size());
+   T.copy(output_length-hash_size, msg, msg.size());
+   return T;
+   }
+
+}
+
+/*************************************************
+* EMSA3 Update Operation                         *
+*************************************************/
+void EMSA3::update(const byte input[], u32bit length)
+   {
+   hash->update(input, length);
+   }
+
+/*************************************************
+* Return the raw (unencoded) data                *
+*************************************************/
+SecureVector<byte> EMSA3::raw_data()
+   {
+   return hash->final();
+   }
+
+/*************************************************
+* EMSA3 Encode Operation                         *
+*************************************************/
+SecureVector<byte> EMSA3::encoding_of(const MemoryRegion<byte>& msg,
+                                      u32bit output_bits,
+                                      RandomNumberGenerator&)
+   {
+   return emsa3_encoding(msg, output_bits, hash_id,
+                         hash->OUTPUT_LENGTH);
+   }
+
+/*************************************************
+* Default signature decoding                     *
+*************************************************/
+bool EMSA3::verify(const MemoryRegion<byte>& coded,
+                   const MemoryRegion<byte>& raw,
+                   u32bit key_bits) throw()
+   {
+   try
+      {
+      return (coded == emsa3_encoding(raw, key_bits,
+                                      hash_id,
+                                      hash->OUTPUT_LENGTH));
+      }
+   catch(...)
+      {
+      return false;
+      }
+   }
+
+/*************************************************
+* EMSA3 Constructor                              *
+*************************************************/
+EMSA3::EMSA3(const std::string& hash_name)
+   {
+   hash_id = pkcs_hash_id(hash_name);
+   hash = get_hash(hash_name);
+   }
+
+}