Reorganize the EMSA classes, and remove the last references to prng_reference

in the library ccode.

1 files changed, 50 insertions, 16 deletions

diff --git a/src/emsa3.cpp b/src/emsa3.cpp
index cf1aae3fa..35a9f6fe3 100644
--- a/src/emsa3.cpp
+++ b/src/emsa3.cpp
@@ -9,6 +9,36 @@
 
 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                         *
 *************************************************/
@@ -32,23 +62,27 @@ SecureVector<byte> EMSA3::encoding_of(const MemoryRegion<byte>& msg,
                                       u32bit output_bits,
                                       RandomNumberGenerator&)
    {
-   if(msg.size() != hash->OUTPUT_LENGTH)
-      throw Encoding_Error("EMSA3::encoding_of: Bad input length");
-
-   u32bit output_length = output_bits / 8;
-   if(output_length < hash_id.size() + hash->OUTPUT_LENGTH + 10)
-      throw Encoding_Error("EMSA3::pad: Output length is too small");
-
-   SecureVector<byte> T(output_length);
-   const u32bit P_LENGTH = output_length - hash->OUTPUT_LENGTH -
-                           hash_id.size() - 2;
+   return emsa3_encoding(msg, output_bits, hash_id,
+                         hash->OUTPUT_LENGTH);
+   }
 
-   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->OUTPUT_LENGTH, msg, msg.size());
-   return T;
+/*************************************************
+* 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;
+      }
    }
 
 /*************************************************