propagate from branch 'net.randombit.botan.aead-modes' (head 9f75a9bcacc77447b2916104f0ccbabd2c93b516)

            to branch 'net.randombit.botan' (head 9e94d89357c08ffc5f7cb5cc3e86c755da96ca8e)

6 files changed, 409 insertions, 9 deletions

diff --git a/src/engine/core_engine/core_modes.cpp b/src/engine/core_engine/core_modes.cpp
index 08124a3a0..b30097eaa 100644
--- a/src/engine/core_engine/core_modes.cpp
+++ b/src/engine/core_engine/core_modes.cpp
@@ -44,6 +44,10 @@
   #include <botan/ocb.h>
 #endif
 
+#if defined(BOTAN_HAS_GCM)
+  #include <botan/gcm.h>
+#endif
+
 #if defined(BOTAN_HAS_XTS)
   #include <botan/xts.h>
 #endif
@@ -141,6 +145,16 @@ Keyed_Filter* get_cipher_mode(const BlockCipher* block_cipher,
       }
 #endif
 
+#if defined(BOTAN_HAS_GCM)
+   if(mode == "GCM")
+      {
+      if(direction == ENCRYPTION)
+         return new GCM_Encryption(block_cipher->clone(), 16);
+      else
+         return new GCM_Decryption(block_cipher->clone(), 16);
+      }
+#endif
+
 #if defined(BOTAN_HAS_XTS)
    if(mode == "XTS")
       {
diff --git a/src/filters/modes/gcm/gcm.cpp b/src/filters/modes/gcm/gcm.cpp
new file mode 100644
index 000000000..527310069
--- /dev/null
+++ b/src/filters/modes/gcm/gcm.cpp
@@ -0,0 +1,253 @@
+/*
+* GCM Mode Encryption
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/gcm.h>
+#include <botan/ctr.h>
+#include <botan/internal/xor_buf.h>
+#include <botan/loadstor.h>
+
+namespace Botan {
+
+secure_vector<byte>
+gcm_multiply(const secure_vector<byte>& x,
+             const secure_vector<byte>& y)
+   {
+   static const u64bit R = 0xE100000000000000;
+
+   u64bit V[2] = {
+      load_be<u64bit>(&y[0], 0),
+      load_be<u64bit>(&y[0], 1)
+   };
+
+   u64bit Z[2] = { 0, 0 };
+
+   for(size_t i = 0; i != 2; ++i)
+      {
+      u64bit X = load_be<u64bit>(&x[0], i);
+
+      for(size_t j = 0; j != 64; ++j)
+         {
+         if(X >> 63)
+            {
+            Z[0] ^= V[0];
+            Z[1] ^= V[1];
+            }
+
+         const u64bit r = (V[1] & 1) ? R : 0;
+
+         V[1] = (V[0] << 63) | (V[1] >> 1);
+         V[0] = (V[0] >> 1) ^ r;
+
+         X <<= 1;
+         }
+      }
+
+   secure_vector<byte> out(16);
+   store_be<u64bit>(&out[0], Z[0], Z[1]);
+   return out;
+   }
+
+void ghash_update(const secure_vector<byte>& H,
+                  secure_vector<byte>& ghash,
+                  const byte input[], size_t length)
+   {
+   const size_t BS = 16;
+
+   /*
+   This assumes if less than block size input then we're just on the
+   final block and should pad with zeros
+   */
+   while(length)
+      {
+      const size_t to_proc = std::min(length, BS);
+
+      xor_buf(&ghash[0], &input[0], to_proc);
+
+      ghash = gcm_multiply(ghash, H);
+
+      input += to_proc;
+      length -= to_proc;
+      }
+   }
+
+void ghash_finalize(const secure_vector<byte>& H,
+                    secure_vector<byte>& ghash,
+                    size_t ad_len, size_t text_len)
+   {
+   secure_vector<byte> final_block(16);
+   store_be<u64bit>(&final_block[0], 8*ad_len, 8*text_len);
+   ghash_update(H, ghash, &final_block[0], final_block.size());
+   }
+
+/*
+* GCM_Mode Constructor
+*/
+GCM_Mode::GCM_Mode(BlockCipher* cipher, size_t tag_size, bool decrypting) :
+   Buffered_Filter(cipher->parallel_bytes(), decrypting ? tag_size : 0),
+   m_tag_size(tag_size), m_cipher_name(cipher->name()),
+   m_H(16), m_H_ad(16), m_mac(16),
+   m_ad_len(0), m_text_len(0),
+   m_ctr_buf(8 * cipher->parallel_bytes())
+   {
+   if(cipher->block_size() != BS)
+      throw std::invalid_argument("OCB requires a 128 bit cipher so cannot be used with " +
+                                  cipher->name());
+
+   m_ctr.reset(new CTR_BE(cipher)); // CTR_BE takes ownership of cipher
+
+   if(m_tag_size < 8 || m_tag_size > 16)
+      throw Invalid_Argument(name() + ": Bad tag size " + std::to_string(m_tag_size));
+   }
+
+/*
+* Check if a keylength is valid for GCM
+*/
+bool GCM_Mode::valid_keylength(size_t n) const
+   {
+   if(!m_ctr->valid_keylength(n))
+      return false;
+   return true;
+   }
+
+void GCM_Mode::set_key(const SymmetricKey& key)
+   {
+   m_ctr->set_key(key);
+
+   const std::vector<byte> zeros(BS);
+   m_ctr->set_iv(&zeros[0], zeros.size());
+
+   zeroise(m_H);
+   m_ctr->cipher(&m_H[0], &m_H[0], m_H.size());
+   }
+
+/*
+* Set the GCM associated data
+*/
+void GCM_Mode::set_associated_data(const byte ad[], size_t ad_len)
+   {
+   zeroise(m_H_ad);
+
+   ghash_update(m_H, m_H_ad, ad, ad_len);
+   m_ad_len = ad_len;
+   }
+
+/*
+* Set the GCM nonce
+*/
+void GCM_Mode::set_nonce(const byte nonce[], size_t nonce_len)
+   {
+   secure_vector<byte> y0(BS);
+
+   if(nonce_len == 12)
+      {
+      copy_mem(&y0[0], nonce, nonce_len);
+      y0[15] = 1;
+      }
+   else
+      {
+      ghash_update(m_H, y0, nonce, nonce_len);
+      ghash_finalize(m_H, y0, 0, nonce_len);
+      }
+
+   m_ctr->set_iv(&y0[0], y0.size());
+
+   m_enc_y0.resize(BS);
+   m_ctr->encipher(m_enc_y0);
+   }
+
+/*
+* Do setup at the start of each message
+*/
+void GCM_Mode::start_msg()
+   {
+   m_text_len = 0;
+   m_mac = m_H_ad;
+   }
+
+/*
+* Return the name of this cipher mode
+*/
+std::string GCM_Mode::name() const
+   {
+   return (m_cipher_name + "/GCM");
+   }
+
+void GCM_Mode::write(const byte input[], size_t length)
+   {
+   Buffered_Filter::write(input, length);
+   }
+
+void GCM_Mode::end_msg()
+   {
+   Buffered_Filter::end_msg();
+   }
+
+void GCM_Encryption::buffered_block(const byte input[], size_t length)
+   {
+   while(length)
+      {
+      size_t copied = std::min<size_t>(length, m_ctr_buf.size());
+
+      m_ctr->cipher(input, &m_ctr_buf[0], copied);
+      ghash_update(m_H, m_mac, &m_ctr_buf[0], copied);
+      m_text_len += copied;
+
+      send(m_ctr_buf, copied);
+
+      input += copied;
+      length -= copied;
+      }
+   }
+
+void GCM_Encryption::buffered_final(const byte input[], size_t input_length)
+   {
+   buffered_block(input, input_length);
+
+   ghash_finalize(m_H, m_mac, m_ad_len, m_text_len);
+
+   m_mac ^= m_enc_y0;
+
+   send(m_mac, m_tag_size);
+   }
+
+void GCM_Decryption::buffered_block(const byte input[], size_t length)
+   {
+   while(length)
+      {
+      size_t copied = std::min<size_t>(length, m_ctr_buf.size());
+
+      ghash_update(m_H, m_mac, &input[0], copied);
+      m_ctr->cipher(input, &m_ctr_buf[0], copied);
+      m_text_len += copied;
+
+      send(m_ctr_buf, copied);
+
+      input += copied;
+      length -= copied;
+      }
+   }
+
+void GCM_Decryption::buffered_final(const byte input[], size_t input_length)
+   {
+   BOTAN_ASSERT(input_length >= m_tag_size, "Have the tag as part of final input");
+
+   const byte* included_tag = &input[input_length - m_tag_size];
+   input_length -= m_tag_size;
+
+   if(input_length) // handle any remaining input
+      buffered_block(input, input_length);
+
+   ghash_finalize(m_H, m_mac, m_ad_len, m_text_len);
+
+   m_mac ^= m_enc_y0;
+
+   if(!same_mem(&m_mac[0], included_tag, m_tag_size))
+      throw Integrity_Failure("GCM tag check failed");
+   }
+
+
+}
diff --git a/src/filters/modes/gcm/gcm.h b/src/filters/modes/gcm/gcm.h
new file mode 100644
index 000000000..fa13597ce
--- /dev/null
+++ b/src/filters/modes/gcm/gcm.h
@@ -0,0 +1,101 @@
+/*
+* GCM Mode
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_GCM_H__
+#define BOTAN_GCM_H__
+
+#include <botan/aead.h>
+#include <botan/buf_filt.h>
+#include <botan/block_cipher.h>
+#include <botan/stream_cipher.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* GCM Mode
+*/
+class BOTAN_DLL GCM_Mode : public AEAD_Mode,
+                           private Buffered_Filter
+   {
+   public:
+      void set_key(const SymmetricKey& key) override;
+
+      void set_nonce(const byte nonce[], size_t nonce_len) override;
+
+      /**
+      * @note must be called before start_msg or not at all
+      */
+      void set_associated_data(const byte ad[], size_t ad_len) override;
+
+      bool valid_keylength(size_t key_len) const override;
+
+      // GCM supports arbitrary IV lengths
+      bool valid_iv_length(size_t) const override { return true; }
+
+      std::string name() const override;
+   protected:
+      GCM_Mode(BlockCipher* cipher, size_t tag_size, bool decrypting);
+
+      static const size_t BS = 16;
+
+      const size_t m_tag_size;
+      const std::string m_cipher_name;
+
+      std::unique_ptr<StreamCipher> m_ctr;
+      secure_vector<byte> m_H;
+      secure_vector<byte> m_H_ad;
+      secure_vector<byte> m_mac;
+      secure_vector<byte> m_enc_y0;
+      size_t m_ad_len, m_text_len;
+      secure_vector<byte> m_ctr_buf;
+
+   private:
+      void write(const byte[], size_t);
+      void start_msg();
+      void end_msg();
+   };
+
+/**
+* GCM Encryption
+*/
+class BOTAN_DLL GCM_Encryption : public GCM_Mode
+   {
+   public:
+      /**
+      * @param ciph the cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      GCM_Encryption(BlockCipher* ciph, size_t tag_size = 16) :
+         GCM_Mode(ciph, tag_size, false) {}
+
+   private:
+      void buffered_block(const byte input[], size_t input_length) override;
+      void buffered_final(const byte input[], size_t input_length) override;
+   };
+
+/**
+* GCM Decryption
+*/
+class BOTAN_DLL GCM_Decryption : public GCM_Mode
+   {
+   public:
+      /**
+      * @param ciph the cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      GCM_Decryption(BlockCipher* cipher, size_t tag_size = 16) :
+         GCM_Mode(cipher, tag_size, true) {}
+
+   private:
+      void buffered_block(const byte input[], size_t input_length) override;
+      void buffered_final(const byte input[], size_t input_length) override;
+   };
+
+}
+
+#endif
diff --git a/src/filters/modes/gcm/info.txt b/src/filters/modes/gcm/info.txt
new file mode 100644
index 000000000..52e677a03
--- /dev/null
+++ b/src/filters/modes/gcm/info.txt
@@ -0,0 +1,6 @@
+define GCM
+
+<requires>
+block
+ctr
+</requires>
diff --git a/src/selftest/selftest.cpp b/src/selftest/selftest.cpp
index 4be0fa4cf..e291a8e9d 100644
--- a/src/selftest/selftest.cpp
+++ b/src/selftest/selftest.cpp
@@ -1,12 +1,14 @@
 /*
 * Startup Self Tests
-* (C) 1999-2007 Jack Lloyd
+* (C) 1999-2007,2013 Jack Lloyd
 *
 * Distributed under the terms of the Botan license
 */
 
 #include <botan/selftest.h>
 #include <botan/filters.h>
+#include <botan/aead.h>
+#include <botan/hex.h>
 #include <botan/internal/core_engine.h>
 #include <botan/internal/stl_util.h>
 
@@ -23,17 +25,24 @@ std::string test_filter_kat(Filter* filter,
                             const std::string& input,
                             const std::string& expected)
    {
-   Pipe pipe(new Hex_Decoder, filter, new Hex_Encoder);
-   pipe.process_msg(input);
+   try
+      {
+      Pipe pipe(new Hex_Decoder, filter, new Hex_Encoder);
+      pipe.process_msg(input);
 
-   const std::string got = pipe.read_all_as_string();
+      const std::string got = pipe.read_all_as_string();
 
-   const bool same = (got == expected);
+      const bool same = (got == expected);
 
-   if(same)
-      return "passed";
-   else
-      return (std::string("got ") + got + " expected " + expected);
+      if(same)
+         return "passed";
+      else
+         return (std::string("got ") + got + " expected " + expected);
+      }
+   catch(std::exception& e)
+      {
+      return std::string("exception ") + e.what();
+      }
    }
 
 }
@@ -117,6 +126,19 @@ algorithm_kat_detailed(const SCAN_Name& algo_name,
          else if(!dec->valid_iv_length(0))
             throw Invalid_IV_Length(algo, iv.length());
 
+#if defined(BOTAN_HAS_AEAD)
+
+         if(AEAD_Mode* enc_aead = dynamic_cast<AEAD_Mode*>(enc))
+            {
+            const std::vector<byte> ad = hex_decode(search_map(vars, std::string("ad")));
+
+            enc_aead->set_associated_data(&ad[0], ad.size());
+
+            if(AEAD_Mode* dec_aead = dynamic_cast<AEAD_Mode*>(dec))
+               dec_aead->set_associated_data(&ad[0], ad.size());
+            }
+#endif
+
          all_results[provider + " (encrypt)"] = test_filter_kat(enc, input, output);
          all_results[provider + " (decrypt)"] = test_filter_kat(dec, output, input);
          }
diff --git a/src/stream/stream_cipher.h b/src/stream/stream_cipher.h
index 301e71f07..231414589 100644
--- a/src/stream/stream_cipher.h
+++ b/src/stream/stream_cipher.h
@@ -34,6 +34,10 @@ class BOTAN_DLL StreamCipher : public SymmetricAlgorithm
       void cipher1(byte buf[], size_t len)
          { cipher(buf, buf, len); }
 
+      template<typename Alloc>
+         void encipher(std::vector<byte, Alloc>& inout)
+         { cipher(&inout[0], &inout[0], inout.size()); }
+
       /**
       * Resync the cipher using the IV
       * @param iv the initialization vector