libsecurity_apple_csp/lib/castContext.h

   1 /*
   2  * Copyright (c) 2000-2001 Apple Computer, 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  * castContext.h - glue between BlockCrytpor and ssleay CAST-128 (CAST5)
  21  *                               implementation
  22  *
  23  * Written by Doug Mitchell 4/24/2003
  24  *
  25  * Here's what RFC 2144 has to say about CAST128 and CAST5 nomenclature:
  26  *
  27  *    In order to avoid confusion when variable keysize operation is
  28  *    used, the name CAST-128 is to be considered synonymous with the
  29  *    name CAST5; this allows a keysize to be appended without ambiguity.
  30  *    Thus, for example, CAST-128 with a 40-bit key is to be referred to
  31  *    as CAST5-40; where a 128-bit key is explicitly intended, the
  32  *    name CAST5-128 should be used.
  33  *
  34  * This module implements a variable key length, from 40 bits to 128 bits,
  35  * and can thus be said to implement both CAST-128 and CAST5.
  36  */
  37
  38 #ifndef _CAST_CONTEXT_H_
  39 #define _CAST_CONTEXT_H_
  40
  41 #include "AppleCSPContext.h"
  42 #include "BlockCryptor.h"
  43 #include <CoreServices/../Frameworks/CarbonCore.framework/Headers/MacTypes.h>
  44 #include <CommonCrypto/CommonCryptor.h>
  45 #include "/usr/local/include/CommonCrypto/CommonCryptorSPI.h"
  46
  47 class CastContext : public BlockCryptor {
  48 public:
  49         CastContext(AppleCSPSession &session);
  50         virtual ~CastContext();
  51
  52         // called by CSPFullPluginSession
  53         void init(const Context &context, bool encoding = true);
  54
  55         // As an optimization, we allow reuse of a modified context.
  56         // The main thing we avoid is a redundant key scheduling. We
  57         // save the current raw keys bits in mRawKey and compare on
  58         // re-init.
  59         bool changed(const Context &context)     { return true; }
  60
  61         // called by BlockCryptor
  62         void encryptBlock(
  63                 const void              *plainText,             // length implied (one block)
  64                 size_t                  plainTextLen,
  65                 void                    *cipherText,
  66                 size_t                  &cipherTextLen, // in/out, throws on overflow
  67                 bool                    final);
  68         void decryptBlock(
  69                 const void              *cipherText,    // length implied (one cipher block)
  70                 size_t                  cipherTextLen,
  71                 void                    *plainText,
  72                 size_t                  &plainTextLen,  // in/out, throws on overflow
  73                 bool                    final);
  74
  75 private:
  76         void deleteKey();
  77
  78         /* scheduled key */
  79     CCCryptorRef        mCastKey;
  80
  81         bool                            mInitFlag;                      // for easy reuse
  82
  83         /*
  84          * Raw key bits saved here and checked on re-init to avoid
  85          * extra key schedule
  86          */
  87         uint8                           mRawKey[kCCKeySizeMaxCAST];
  88         uint32                          mRawKeySize;
  89
  90
  91 };      /* CastContext */
  92
  93 #endif //_CAST_CONTEXT_H_