1 files changed, 174 insertions, 0 deletions
diff --git a/src/ssl/c_kex.cpp b/src/ssl/c_kex.cpp
new file mode 100644
index 000000000..298b22a89
--- /dev/null
+++ b/src/ssl/c_kex.cpp
@@ -0,0 +1,174 @@
+/**
+* Client Key Exchange Message Source File
+* (C) 2004-2008 Jack Lloyd
+*
+* Released under the terms of the Botan license
+*/
+
+#include <botan/tls_messages.h>
+#include <botan/dh.h>
+#include <botan/rsa.h>
+#include <botan/rng.h>
+#include <botan/look_pk.h>
+#include <botan/loadstor.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* Create a new Client Key Exchange message
+*/
+Client_Key_Exchange::Client_Key_Exchange(RandomNumberGenerator& rng,
+                                         Record_Writer& writer,
+                                         HandshakeHash& hash,
+                                         const X509_PublicKey* pub_key,
+                                         Version_Code using_version,
+                                         Version_Code pref_version)
+   {
+   const DH_PublicKey* dh_pub = dynamic_cast<const DH_PublicKey*>(pub_key);
+   const RSA_PublicKey* rsa_pub = dynamic_cast<const RSA_PublicKey*>(pub_key);
+
+   include_length = true;
+
+   if(dh_pub)
+      {
+      DH_PrivateKey priv_key(rng, dh_pub->get_domain());
+      pre_master = priv_key.derive_key(dh_pub->get_y());
+      key_material = priv_key.public_value();
+      }
+   else if(rsa_pub)
+      {
+      pre_master.resize(48);
+      rng.randomize(pre_master, 48);
+      pre_master[0] = (pref_version >> 8) & 0xFF;
+      pre_master[1] = (pref_version     ) & 0xFF;
+
+      std::auto_ptr<PK_Encryptor> encryptor(get_pk_encryptor(*rsa_pub,
+                                                             "PKCS1v15"));
+
+      key_material = encryptor->encrypt(pre_master, rng);
+
+      if(using_version == SSL_V3)
+         include_length = false;
+      }
+   else
+      throw Invalid_Argument("Client_Key_Exchange: Key not RSA or DH");
+
+   send(writer, hash);
+   }
+
+/**
+* Read a Client Key Exchange message
+*/
+Client_Key_Exchange::Client_Key_Exchange(const MemoryRegion<byte>& contents,
+                                         const CipherSuite& suite,
+                                         Version_Code using_version)
+   {
+   include_length = true;
+
+   if(using_version == SSL_V3 &&
+      (suite.kex_type() == CipherSuite::NO_KEX ||
+       suite.kex_type() == CipherSuite::RSA_KEX))
+      include_length = false;
+
+   deserialize(contents);
+   }
+
+/**
+* Serialize a Client Key Exchange message
+*/
+SecureVector<byte> Client_Key_Exchange::serialize() const
+   {
+   SecureVector<byte> buf;
+
+   if(include_length)
+      {
+      u16bit key_size = key_material.size();
+      buf.append(get_byte(0, key_size));
+      buf.append(get_byte(1, key_size));
+      }
+   buf.append(key_material);
+
+   return buf;
+   }
+
+/**
+* Deserialize a Client Key Exchange message
+*/
+void Client_Key_Exchange::deserialize(const MemoryRegion<byte>& buf)
+   {
+   if(include_length)
+      {
+      if(buf.size() < 2)
+         throw Decoding_Error("Client_Key_Exchange: Packet corrupted");
+
+      u32bit size = make_u16bit(buf[0], buf[1]);
+      if(size + 2 != buf.size())
+         throw Decoding_Error("Client_Key_Exchange: Packet corrupted");
+
+      key_material.set(buf + 2, size);
+      }
+   else
+      key_material = buf;
+   }
+
+/**
+* Return the pre_master_secret
+*/
+SecureVector<byte>
+Client_Key_Exchange::pre_master_secret(RandomNumberGenerator& rng,
+                                       const PKCS8_PrivateKey* priv_key,
+                                       Version_Code version)
+   {
+   const DH_PrivateKey* dh_priv = dynamic_cast<const DH_PrivateKey*>(priv_key);
+   const RSA_PrivateKey* rsa_priv =
+      dynamic_cast<const RSA_PrivateKey*>(priv_key);
+
+   if(dh_priv)
+      {
+      try {
+         pre_master = dh_priv->derive_key(key_material, key_material.size());
+      }
+      catch(std::exception& e)
+         {
+         pre_master.resize(dh_priv->public_value().size());
+         rng.randomize(pre_master, pre_master.size());
+         }
+
+      return pre_master;
+      }
+   else if(rsa_priv)
+      {
+      std::auto_ptr<PK_Decryptor> decryptor(get_pk_decryptor(*rsa_priv,
+                                                             "PKCS1v15"));
+
+      try {
+         pre_master = decryptor->decrypt(key_material);
+
+         if(pre_master.size() != 48 ||
+            make_u16bit(pre_master[0], pre_master[1]) != version)
+            throw Decoding_Error("Client_Key_Exchange: Secret corrupted");
+      }
+      catch(std::exception)
+         {
+         pre_master.resize(48);
+         rng.randomize(pre_master, pre_master.size());
+         pre_master[0] = (version >> 8) & 0xFF;
+         pre_master[1] = (version     ) & 0xFF;
+         }
+
+      return pre_master;
+      }
+   else
+      throw Invalid_Argument("Client_Key_Exchange: Bad key for decrypt");
+   }
+
+/**
+* Return the pre_master_secret
+*/
+SecureVector<byte> Client_Key_Exchange::pre_master_secret() const
+   {
+   return pre_master;
+   }
+
+}