Security/libsecurity_cdsa_utilities/lib/digestobject.h

   1 /*
   2  * Copyright (c) 2000-2004,2006,2011,2013-2014 Apple 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 <security_cdsa_utilities/cssmalloc.h>
  33
  34 /* common virtual digest class */
  35 class DigestObject {
  36 public:
  37         DigestObject() : mInitFlag(false), mIsDone(false) { }
  38         virtual ~DigestObject() { }
  39
  40         /*
  41          * The remaining functions must be implemented by subclass.
  42          */
  43         /* init is reusable */
  44         virtual void digestInit() = 0;
  45
  46         /* add some data */
  47         virtual void digestUpdate(
  48                 const void *data,
  49                 size_t          len) = 0;
  50
  51         /* obtain digest (once only per init, update, ... cycle) */
  52         virtual void digestFinal(
  53                 void            *digest) = 0;   /* RETURNED, alloc'd by caller */
  54
  55         /* sublass-specific copy */
  56         virtual DigestObject *digestClone() const = 0;
  57
  58         virtual size_t digestSizeInBytes() const = 0;
  59
  60 protected:
  61         bool                    mInitFlag;
  62         bool                    mIsDone;
  63
  64         bool                    initFlag()                              { return mInitFlag; }
  65         void                    setInitFlag(bool flag)  { mInitFlag = flag; }
  66         bool                    isDone()                                { return mIsDone; }
  67         void                    setIsDone(bool done)    { mIsDone = done; }
  68 };
  69
  70 /*
  71  * NullDigest.h - nop digest for use with raw signature algorithms.
  72  *                                NullDigest(someData) = someData.
  73  */
  74 class NullDigest : public DigestObject
  75 {
  76 public:
  77         NullDigest() : mInBuf(NULL), mInBufSize(0)
  78         {
  79         }
  80
  81         void digestInit()
  82         {
  83                 /* reusable - reset */
  84                 if(mInBufSize) {
  85                         assert(mInBuf != NULL);
  86                         memset(mInBuf, 0, mInBufSize);
  87                         Allocator::standard().free(mInBuf);
  88                         mInBufSize = 0;
  89                         mInBuf = NULL;
  90                 }
  91         }
  92
  93         ~NullDigest()
  94         {
  95                 digestInit();
  96         }
  97
  98         void digestUpdate(
  99                 const void *data,
 100                 size_t          len)
 101         {
 102                 mInBuf = Allocator::standard().realloc(mInBuf, mInBufSize + len);
 103                 memmove((uint8 *)mInBuf + mInBufSize, data, len);
 104                 mInBufSize += len;
 105         }
 106
 107         virtual void digestFinal(
 108                 void            *digest)
 109         {
 110                 memmove(digest, mInBuf, mInBufSize);
 111         }
 112
 113         virtual DigestObject *digestClone() const
 114         {
 115                 NullDigest *cloned = new NullDigest;
 116                 cloned->digestUpdate(mInBuf, mInBufSize);
 117                 return cloned;
 118         }
 119
 120         /* unique to NullDigest - just obtain current data ptr, no copy */
 121         virtual const void *digestPtr() { return mInBuf; }
 122
 123         size_t digestSizeInBytes() const
 124         {
 125                 return mInBufSize;
 126         }
 127
 128 private:
 129         void            *mInBuf;
 130         size_t          mInBufSize;
 131 };
 132
 133 #endif  /* _DIGEST_OBJECT_H_ */