Make TLS CBC optional

1 files changed, 168 insertions, 0 deletions

diff --git a/src/lib/tls/tls_cbc/tls_cbc.h b/src/lib/tls/tls_cbc/tls_cbc.h
new file mode 100644
index 000000000..90b54bb5a
--- /dev/null
+++ b/src/lib/tls/tls_cbc/tls_cbc.h
@@ -0,0 +1,168 @@
+/*
+* TLS CBC+HMAC AEAD
+* (C) 2016 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_TLS_CBC_HMAC_AEAD_H__
+#define BOTAN_TLS_CBC_HMAC_AEAD_H__
+
+#include <botan/aead.h>
+#include <botan/block_cipher.h>
+#include <botan/mac.h>
+
+namespace Botan {
+
+namespace TLS {
+
+/**
+* TLS CBC+HMAC AEAD base class (GenericBlockCipher in TLS spec)
+* This is the weird TLS-specific mode, not for general consumption.
+*/
+class TLS_CBC_HMAC_AEAD_Mode : public AEAD_Mode
+   {
+   public:
+      size_t process(uint8_t buf[], size_t sz) override final;
+
+      std::string name() const override final;
+
+      void set_associated_data(const byte ad[], size_t ad_len) override;
+
+      size_t update_granularity() const override final;
+
+      Key_Length_Specification key_spec() const override final;
+
+      bool valid_nonce_length(size_t nl) const override final;
+
+      size_t tag_size() const override final { return m_tag_size; }
+
+      size_t default_nonce_length() const override final { return m_iv_size; }
+
+      void clear() override final;
+
+ protected:
+      TLS_CBC_HMAC_AEAD_Mode(const std::string& cipher_name,
+                             size_t cipher_keylen,
+                             const std::string& mac_name,
+                             size_t mac_keylen,
+                             bool use_explicit_iv,
+                             bool use_encrypt_then_mac);
+
+      size_t cipher_keylen() const { return m_cipher_keylen; }
+      size_t mac_keylen() const { return m_mac_keylen; }
+      size_t iv_size() const { return m_iv_size; }
+      size_t block_size() const { return m_block_size; }
+
+      bool use_encrypt_then_mac() const { return m_use_encrypt_then_mac; }
+
+      BlockCipher& cipher() const
+         {
+         BOTAN_ASSERT_NONNULL(m_cipher);
+         return *m_cipher;
+         }
+
+      MessageAuthenticationCode& mac() const
+         {
+         BOTAN_ASSERT_NONNULL(m_mac);
+         return *m_mac;
+         }
+
+      secure_vector<byte>& cbc_state() { return m_cbc_state; }
+      std::vector<byte>& assoc_data() { return m_ad; }
+      secure_vector<byte>& msg() { return m_msg; }
+
+      std::vector<byte> assoc_data_with_len(uint16_t len);
+
+   private:
+      void start_msg(const byte nonce[], size_t nonce_len) override final;
+
+      void key_schedule(const byte key[], size_t length) override final;
+
+      const std::string m_cipher_name;
+      const std::string m_mac_name;
+      size_t m_cipher_keylen;
+      size_t m_mac_keylen;
+      size_t m_iv_size;
+      size_t m_tag_size;
+      size_t m_block_size;
+      bool m_use_encrypt_then_mac;
+
+      std::unique_ptr<BlockCipher> m_cipher;
+      std::unique_ptr<MessageAuthenticationCode> m_mac;
+
+      secure_vector<byte> m_cbc_state;
+      std::vector<byte> m_ad;
+      secure_vector<byte> m_msg;
+   };
+
+/**
+* TLS_CBC_HMAC_AEAD Encryption
+*/
+class BOTAN_DLL TLS_CBC_HMAC_AEAD_Encryption final : public TLS_CBC_HMAC_AEAD_Mode
+   {
+   public:
+      /**
+      */
+      TLS_CBC_HMAC_AEAD_Encryption(const std::string& cipher_algo,
+                                   const size_t cipher_keylen,
+                                   const std::string& mac_algo,
+                                   const size_t mac_keylen,
+                                   bool use_explicit_iv,
+                                   bool use_encrypt_then_mac) :
+         TLS_CBC_HMAC_AEAD_Mode(cipher_algo,
+                                cipher_keylen,
+                                mac_algo,
+                                mac_keylen,
+                                use_explicit_iv,
+                                use_encrypt_then_mac)
+         {}
+
+      void set_associated_data(const byte ad[], size_t ad_len) override;
+
+      size_t output_length(size_t input_length) const override;
+
+      size_t minimum_final_size() const override { return 0; }
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+   private:
+      void cbc_encrypt_record(byte record_contents[], size_t record_len);
+   };
+
+/**
+* TLS_CBC_HMAC_AEAD Decryption
+*/
+class BOTAN_DLL TLS_CBC_HMAC_AEAD_Decryption final : public TLS_CBC_HMAC_AEAD_Mode
+   {
+   public:
+      /**
+      */
+      TLS_CBC_HMAC_AEAD_Decryption(const std::string& cipher_algo,
+                                   const size_t cipher_keylen,
+                                   const std::string& mac_algo,
+                                   const size_t mac_keylen,
+                                   bool use_explicit_iv,
+                                   bool use_encrypt_then_mac) :
+         TLS_CBC_HMAC_AEAD_Mode(cipher_algo,
+                                cipher_keylen,
+                                mac_algo,
+                                mac_keylen,
+                                use_explicit_iv,
+                                use_encrypt_then_mac)
+         {}
+
+      size_t output_length(size_t input_length) const override;
+
+      size_t minimum_final_size() const override { return tag_size(); }
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+   private:
+      void cbc_decrypt_record(byte record_contents[], size_t record_len);
+   };
+
+}
+
+}
+
+#endif