libsecurity_cdsa_utilities/lib/digestobject.h

   1 /*
   2  * Copyright (c) 2000-2004,2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24
  25 /*
  26  * digestobject.h - generic virtual Digest base class
  27  */
  28
  29 #ifndef _DIGEST_OBJECT_H_
  30 #define _DIGEST_OBJECT_H_
  31
  32 #include <CoreServices/../Frameworks/CarbonCore.framework/Headers/MacTypes.h>
  33 #include <security_cdsa_utilities/cssmalloc.h>
  34
  35 /* common virtual digest class */
  36 class DigestObject {
  37 public:
  38         DigestObject() : mInitFlag(false), mIsDone(false) { }
  39         virtual ~DigestObject() { }
  40
  41         /*
  42          * The remaining functions must be implemented by subclass.
  43          */
  44         /* init is reusable */
  45         virtual void digestInit() = 0;
  46
  47         /* add some data */
  48         virtual void digestUpdate(
  49                 const void *data,
  50                 size_t          len) = 0;
  51
  52         /* obtain digest (once only per init, update, ... cycle) */
  53         virtual void digestFinal(
  54                 void            *digest) = 0;   /* RETURNED, alloc'd by caller */
  55
  56         /* sublass-specific copy */
  57         virtual DigestObject *digestClone() const = 0;
  58
  59         virtual size_t digestSizeInBytes() const = 0;
  60
  61 protected:
  62         bool                    mInitFlag;
  63         bool                    mIsDone;
  64
  65         bool                    initFlag()                              { return mInitFlag; }
  66         void                    setInitFlag(bool flag)  { mInitFlag = flag; }
  67         bool                    isDone()                                { return mIsDone; }
  68         void                    setIsDone(bool done)    { mIsDone = done; }
  69 };
  70
  71 /*
  72  * NullDigest.h - nop digest for use with raw signature algorithms.
  73  *                                NullDigest(someData) = someData.
  74  */
  75 class NullDigest : public DigestObject
  76 {
  77 public:
  78         NullDigest() : mInBuf(NULL), mInBufSize(0)
  79         {
  80         }
  81
  82         void digestInit()
  83         {
  84                 /* reusable - reset */
  85                 if(mInBufSize) {
  86                         assert(mInBuf != NULL);
  87                         memset(mInBuf, 0, mInBufSize);
  88                         Allocator::standard().free(mInBuf);
  89                         mInBufSize = 0;
  90                         mInBuf = NULL;
  91                 }
  92         }
  93
  94         ~NullDigest()
  95         {
  96                 digestInit();
  97         }
  98
  99         void digestUpdate(
 100                 const void *data,
 101                 size_t          len)
 102         {
 103                 mInBuf = Allocator::standard().realloc(mInBuf, mInBufSize + len);
 104                 memmove((uint8 *)mInBuf + mInBufSize, data, len);
 105                 mInBufSize += len;
 106         }
 107
 108         virtual void digestFinal(
 109                 void            *digest)
 110         {
 111                 memmove(digest, mInBuf, mInBufSize);
 112         }
 113
 114         virtual DigestObject *digestClone() const
 115         {
 116                 NullDigest *cloned = new NullDigest;
 117                 cloned->digestUpdate(mInBuf, mInBufSize);
 118                 return cloned;
 119         }
 120
 121         /* unique to NullDigest - just obtain current data ptr, no copy */
 122         virtual const void *digestPtr() { return mInBuf; }
 123
 124         size_t digestSizeInBytes() const
 125         {
 126                 return mInBufSize;
 127         }
 128
 129 private:
 130         void            *mInBuf;
 131         size_t          mInBufSize;
 132 };
 133
 134 #endif  /* _DIGEST_OBJECT_H_ */