OSX/libsecurity_apple_csp/lib/gladmanContext.h

   1 /*
   2  * Copyright (c) 2000-2001,2011,2013-2014 Apple Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 //
  20 // gladmanContext.h - Gladman AES context class
  21 //
  22 #ifndef _H_GLADMAN_CONTEXT
  23 #define _H_GLADMAN_CONTEXT
  24
  25 #include <security_cdsa_plugin/CSPsession.h>
  26 #include "AppleCSP.h"
  27 #include "AppleCSPContext.h"
  28 #include "AppleCSPSession.h"
  29 #include "BlockCryptor.h"
  30 #include <CommonCrypto/CommonCryptor.h>
  31 #include <CommonCrypto/CommonCryptorSPI.h>
  32 #include "aesCommon.h"
  33
  34 #define GLADMAN_BLOCK_SIZE_BYTES        DEFAULT_AES_BLOCK_BYTES
  35
  36 /* Symmetric encryption context */
  37 class GAESContext : public BlockCryptor {
  38 public:
  39         GAESContext(AppleCSPSession &session);
  40         virtual ~GAESContext();
  41
  42         // called by CSPFullPluginSession
  43         void init(const Context &context, bool encoding = true);
  44
  45         // As an optimization, we allow reuse of a modified context. The main thing
  46         // we avoid is a redundant key scheduling. We save the current raw keys bits
  47         // in mRawKey and compare on re-init.
  48         bool changed(const Context &context)     { return true; }
  49
  50         // called by BlockCryptor
  51         void encryptBlock(
  52                 const void              *plainText,                     // length implied (one block)
  53                 size_t                  plainTextLen,
  54                 void                    *cipherText,
  55                 size_t                  &cipherTextLen,         // in/out, throws on overflow
  56                 bool                    final);
  57         void decryptBlock(
  58                 const void              *cipherText,            // length implied (one cipher block)
  59                 size_t                  cipherTextLen,
  60                 void                    *plainText,
  61                 size_t                  &plainTextLen,          // in/out, throws on overflow
  62                 bool                    final);
  63
  64 private:
  65         void deleteKey();
  66
  67         /* scheduled key */
  68     CCCryptorRef        mAesKey;
  69         bool                            mInitFlag;                      // for easy reuse
  70
  71         /*
  72          * Raw key bits saved here and checked on re-init to avoid extra key
  73          * schedule on re-init. We also have to do a new key schedule if
  74          * changing between encrypting and decrypting since the key schedules
  75          * differ for the two.
  76          */
  77         uint8                           mRawKey[MAX_AES_KEY_BITS / 8];
  78         uint32                          mRawKeySize;
  79         bool                            mWasEncrypting;
  80 };      /* AESContext */
  81
  82 #endif //_H_GLADMAN_CONTEXT