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 <CommonCrypto/CommonCryptor.h>
  44 #include <CommonCrypto/CommonCryptorSPI.h>
  45
  46 class CastContext : public BlockCryptor {
  47 public:
  48         CastContext(AppleCSPSession &session);
  49         virtual ~CastContext();
  50
  51         // called by CSPFullPluginSession
  52         void init(const Context &context, bool encoding = true);
  53
  54         // As an optimization, we allow reuse of a modified context.
  55         // The main thing we avoid is a redundant key scheduling. We
  56         // save the current raw keys bits in mRawKey and compare on
  57         // re-init.
  58         bool changed(const Context &context)     { return true; }
  59
  60         // called by BlockCryptor
  61         void encryptBlock(
  62                 const void              *plainText,             // length implied (one block)
  63                 size_t                  plainTextLen,
  64                 void                    *cipherText,
  65                 size_t                  &cipherTextLen, // in/out, throws on overflow
  66                 bool                    final);
  67         void decryptBlock(
  68                 const void              *cipherText,    // length implied (one cipher block)
  69                 size_t                  cipherTextLen,
  70                 void                    *plainText,
  71                 size_t                  &plainTextLen,  // in/out, throws on overflow
  72                 bool                    final);
  73
  74 private:
  75         void deleteKey();
  76
  77         /* scheduled key */
  78     CCCryptorRef        mCastKey;
  79
  80         bool                            mInitFlag;                      // for easy reuse
  81
  82         /*
  83          * Raw key bits saved here and checked on re-init to avoid
  84          * extra key schedule
  85          */
  86         uint8                           mRawKey[kCCKeySizeMaxCAST];
  87         uint32                          mRawKeySize;
  88
  89
  90 };      /* CastContext */
  91
  92 #endif //_CAST_CONTEXT_H_