Remove return value of AEAD_Mode::start as it doesn't seem necessary

and is an extra complication for callers.

Replace the get_aead in lookup.h returning a Filter with one in aead.h
returning AEAD_Mode.

12 files changed, 89 insertions, 42 deletions

diff --git a/src/aead/aead.cpp b/src/aead/aead.cpp
new file mode 100644
index 000000000..62d6d5f44
--- /dev/null
+++ b/src/aead/aead.cpp
@@ -0,0 +1,75 @@
+/*
+* Interface for AEAD modes
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/aead.h>
+#include <botan/libstate.h>
+
+#if defined(BOTAN_HAS_AEAD_EAX)
+  #include <botan/eax.h>
+#endif
+
+#if defined(BOTAN_HAS_AEAD_GCM)
+  #include <botan/gcm.h>
+#endif
+
+#if defined(BOTAN_HAS_AEAD_OCB)
+  #include <botan/ocb.h>
+#endif
+
+namespace Botan {
+
+AEAD_Mode* get_aead(const std::string& algo_spec, Cipher_Dir direction)
+   {
+   Algorithm_Factory& af = global_state().algorithm_factory();
+
+   const std::vector<std::string> algo_parts = split_on(algo_spec, '/');
+   if(algo_parts.empty())
+      throw Invalid_Algorithm_Name(algo_spec);
+
+   const std::string cipher_name = algo_parts[0];
+   const std::string mode_name = algo_parts[1];
+
+   const size_t tag_size = 16; // default for all current AEAD
+
+   const BlockCipher* cipher = af.prototype_block_cipher(cipher_name);
+   if(!cipher)
+      return nullptr;
+
+#if defined(BOTAN_HAS_AEAD_EAX)
+   if(mode_name == "EAX")
+      {
+      if(direction == ENCRYPTION)
+         return new EAX_Encryption(cipher->clone(), tag_size);
+      else
+         return new EAX_Decryption(cipher->clone(), tag_size);
+      }
+#endif
+
+#if defined(BOTAN_HAS_AEAD_GCM)
+   if(mode_name == "GCM")
+      {
+      if(direction == ENCRYPTION)
+         return new GCM_Encryption(cipher->clone(), tag_size);
+      else
+         return new GCM_Decryption(cipher->clone(), tag_size);
+      }
+#endif
+
+#if defined(BOTAN_HAS_AEAD_OCB)
+   if(mode_name == "OCB")
+      {
+      if(direction == ENCRYPTION)
+         return new OCB_Encryption(cipher->clone(), tag_size);
+      else
+         return new OCB_Decryption(cipher->clone(), tag_size);
+      }
+#endif
+
+   return nullptr;
+   }
+
+}
diff --git a/src/aead/aead.h b/src/aead/aead.h
index e0e07e8ab..c4de71857 100644
--- a/src/aead/aead.h
+++ b/src/aead/aead.h
@@ -66,10 +66,10 @@ class AEAD_Mode : public SymmetricAlgorithm
       * @param nonce the per message nonce
       * @param nonce_len length of nonce
       */
-      virtual secure_vector<byte> start(const byte nonce[], size_t nonce_len) = 0;
+      virtual void start(const byte nonce[], size_t nonce_len) = 0;
 
       template<typename Alloc>
-      secure_vector<byte> start_vec(const std::vector<byte, Alloc>& nonce)
+      void start_vec(const std::vector<byte, Alloc>& nonce)
          {
          return start(&nonce[0], nonce.size());
          }
@@ -94,6 +94,11 @@ class AEAD_Mode : public SymmetricAlgorithm
       virtual ~AEAD_Mode() {}
    };
 
+/**
+* Get an AEAD mode by name (eg "AES-128/GCM" or "Serpent/EAX")
+*/
+BOTAN_DLL AEAD_Mode* get_aead(const std::string& name, Cipher_Dir direction);
+
 }
 
 #endif
diff --git a/src/aead/eax/eax.cpp b/src/aead/eax/eax.cpp
index c6aaa9e85..a0e00b6d6 100644
--- a/src/aead/eax/eax.cpp
+++ b/src/aead/eax/eax.cpp
@@ -92,7 +92,7 @@ void EAX_Mode::set_associated_data(const byte ad[], size_t length)
    m_ad_mac = eax_prf(1, block_size(), *m_cmac, ad, length);
    }
 
-secure_vector<byte> EAX_Mode::start(const byte nonce[], size_t nonce_len)
+void EAX_Mode::start(const byte nonce[], size_t nonce_len)
    {
    if(!valid_nonce_length(nonce_len))
       throw Invalid_IV_Length(name(), nonce_len);
@@ -104,8 +104,6 @@ secure_vector<byte> EAX_Mode::start(const byte nonce[], size_t nonce_len)
    for(size_t i = 0; i != block_size() - 1; ++i)
       m_cmac->update(0);
    m_cmac->update(2);
-
-   return secure_vector<byte>();
    }
 
 void EAX_Encryption::update(secure_vector<byte>& buffer, size_t offset)
diff --git a/src/aead/eax/eax.h b/src/aead/eax/eax.h
index 6720bdca4..790f24513 100644
--- a/src/aead/eax/eax.h
+++ b/src/aead/eax/eax.h
@@ -22,7 +22,7 @@ namespace Botan {
 class BOTAN_DLL EAX_Mode : public AEAD_Mode
    {
    public:
-      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+      void start(const byte nonce[], size_t nonce_len) override;
 
       void set_associated_data(const byte ad[], size_t ad_len) override;
 
diff --git a/src/aead/gcm/gcm.cpp b/src/aead/gcm/gcm.cpp
index 665fc4472..fbef36fee 100644
--- a/src/aead/gcm/gcm.cpp
+++ b/src/aead/gcm/gcm.cpp
@@ -153,7 +153,7 @@ void GCM_Mode::set_associated_data(const byte ad[], size_t ad_len)
    m_ad_len = ad_len;
    }
 
-secure_vector<byte> GCM_Mode::start(const byte nonce[], size_t nonce_len)
+void GCM_Mode::start(const byte nonce[], size_t nonce_len)
    {
    if(!valid_nonce_length(nonce_len))
       throw Invalid_IV_Length(name(), nonce_len);
@@ -178,8 +178,6 @@ secure_vector<byte> GCM_Mode::start(const byte nonce[], size_t nonce_len)
 
    m_text_len = 0;
    m_mac = m_H_ad;
-
-   return secure_vector<byte>();
    }
 
 void GCM_Encryption::update(secure_vector<byte>& buffer, size_t offset)
diff --git a/src/aead/gcm/gcm.h b/src/aead/gcm/gcm.h
index bc7eaae20..10a4a3497 100644
--- a/src/aead/gcm/gcm.h
+++ b/src/aead/gcm/gcm.h
@@ -21,7 +21,7 @@ namespace Botan {
 class BOTAN_DLL GCM_Mode : public AEAD_Mode
    {
    public:
-      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+      void start(const byte nonce[], size_t nonce_len) override;
 
       void set_associated_data(const byte ad[], size_t ad_len) override;
 
diff --git a/src/aead/ocb/ocb.cpp b/src/aead/ocb/ocb.cpp
index 4cbd8bde8..20f54dca7 100644
--- a/src/aead/ocb/ocb.cpp
+++ b/src/aead/ocb/ocb.cpp
@@ -215,7 +215,7 @@ void OCB_Mode::set_associated_data(const byte ad[], size_t ad_len)
    m_ad_hash = ocb_hash(*m_L, *m_cipher, &ad[0], ad_len);
    }
 
-secure_vector<byte> OCB_Mode::start(const byte nonce[], size_t nonce_len)
+void OCB_Mode::start(const byte nonce[], size_t nonce_len)
    {
    if(!valid_nonce_length(nonce_len))
       throw Invalid_IV_Length(name(), nonce_len);
@@ -225,8 +225,6 @@ secure_vector<byte> OCB_Mode::start(const byte nonce[], size_t nonce_len)
    m_offset = m_nonce_state->update_nonce(nonce, nonce_len);
    zeroise(m_checksum);
    m_block_index = 0;
-
-   return secure_vector<byte>();
    }
 
 void OCB_Encryption::encrypt(byte buffer[], size_t blocks)
diff --git a/src/aead/ocb/ocb.h b/src/aead/ocb/ocb.h
index d50710a79..597cd9c52 100644
--- a/src/aead/ocb/ocb.h
+++ b/src/aead/ocb/ocb.h
@@ -30,7 +30,7 @@ class Nonce_State;
 class BOTAN_DLL OCB_Mode : public AEAD_Mode
    {
    public:
-      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+      void start(const byte nonce[], size_t nonce_len) override;
 
       void set_associated_data(const byte ad[], size_t ad_len) override;
 
diff --git a/src/filters/aead_filt/aead_filt.cpp b/src/filters/aead_filt/aead_filt.cpp
index f70b8eafe..3588c3980 100644
--- a/src/filters/aead_filt/aead_filt.cpp
+++ b/src/filters/aead_filt/aead_filt.cpp
@@ -72,7 +72,7 @@ void AEAD_Filter::end_msg()
 
 void AEAD_Filter::start_msg()
    {
-   send(m_aead->start_vec(m_nonce.get()));
+   m_aead->start_vec(m_nonce.get());
    }
 
 void AEAD_Filter::buffered_block(const byte input[], size_t input_length)
diff --git a/src/libstate/info.txt b/src/libstate/info.txt
index 9f36d7be8..b0704cd96 100644
--- a/src/libstate/info.txt
+++ b/src/libstate/info.txt
@@ -24,7 +24,6 @@ scan_name.cpp
 
 <requires>
 aes
-aead
 algo_factory
 alloc
 bigint
diff --git a/src/libstate/lookup.cpp b/src/libstate/lookup.cpp
index 5c5f038ee..24a46e3e9 100644
--- a/src/libstate/lookup.cpp
+++ b/src/libstate/lookup.cpp
@@ -108,18 +108,4 @@ Keyed_Filter* get_cipher(const std::string& algo_spec,
                      key, InitializationVector(), direction);
    }
 
-AEAD_Filter* get_aead(const std::string& algo_spec,
-                    Cipher_Dir direction)
-   {
-   std::unique_ptr<Keyed_Filter> c(get_cipher(algo_spec, direction));
-
-   if(AEAD_Filter* aead = dynamic_cast<AEAD_Filter*>(c.get()))
-      {
-      c.release();
-      return aead;
-      }
-
-   return nullptr;
-   }
-
 }
diff --git a/src/libstate/lookup.h b/src/libstate/lookup.h
index c9d1ee707..7387a3471 100644
--- a/src/libstate/lookup.h
+++ b/src/libstate/lookup.h
@@ -11,7 +11,6 @@
 #include <botan/libstate.h>
 #include <botan/engine.h>
 #include <botan/filters.h>
-#include <botan/aead_filt.h>
 #include <botan/mode_pad.h>
 #include <botan/kdf.h>
 #include <botan/eme.h>
@@ -220,17 +219,6 @@ BOTAN_DLL Keyed_Filter* get_cipher(const std::string& algo_spec,
                                    Cipher_Dir direction);
 
 /**
-* Factory method for AEAD filters. No key will be set in the filter.
-*
-* @param algo_spec the name of the desired AEAD mode (eg "AES-128/OCB")
-* @param direction determines whether the filter will be an encrypting or
-* decrypting filter
-* @return pointer to the encryption or decryption filter
-*/
-BOTAN_DLL AEAD_Filter* get_aead(const std::string& algo_spec,
-                              Cipher_Dir direction);
-
-/**
 * Check if an algorithm exists.
 * @param algo_spec the name of the algorithm to check for
 * @return true if the algorithm exists, false otherwise