libsecurity_apple_csp/lib/bfContext.cpp

   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  * bfContext.cpp - glue between BlockCrytpor and ssleay Blowfish
  21  *                               implementation
  22  * Written by Doug Mitchell 4/23/2003
  23  */
  24
  25 #include "bfContext.h"
  26
  27 BlowfishContext::~BlowfishContext()
  28 {
  29         deleteKey();
  30 }
  31
  32 void BlowfishContext::deleteKey()
  33 {
  34         memset(&mBfKey, 0, sizeof(mBfKey));
  35         mInitFlag = false;
  36 }
  37
  38 /*
  39  * Standard CSPContext init, called from CSPFullPluginSession::init().
  40  * Reusable, e.g., query followed by en/decrypt.
  41  */
  42 void BlowfishContext::init(
  43         const Context &context,
  44         bool encrypting)
  45 {
  46         if(mInitFlag && !opStarted()) {
  47                 return;
  48         }
  49
  50         CSSM_SIZE       keyLen;
  51         uint8           *keyData = NULL;
  52         bool            sameKeySize = false;
  53
  54         /* obtain key from context */
  55         symmetricKeyBits(context, session(), CSSM_ALGID_BLOWFISH,
  56                 encrypting ? CSSM_KEYUSE_ENCRYPT : CSSM_KEYUSE_DECRYPT,
  57                 keyData, keyLen);
  58         if((keyLen < BF_MIN_KEY_SIZE_BYTES) || (keyLen > BF_MAX_KEY_SIZE_BYTES)) {
  59                 CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_KEY);
  60         }
  61
  62         /*
  63          * Delete existing key if key size changed
  64          */
  65         if(mRawKeySize == keyLen) {
  66                 sameKeySize = true;
  67         }
  68         else {
  69                 deleteKey();
  70         }
  71
  72         /* init key only if key size or key bits have changed */
  73         if(!sameKeySize || memcmp(mRawKey, keyData, mRawKeySize)) {
  74                 BF_set_key(&mBfKey, keyLen, keyData);
  75
  76                 /* save this raw key data */
  77                 memmove(mRawKey, keyData, keyLen);
  78                 mRawKeySize = keyLen;
  79         }
  80
  81         /* Finally, have BlockCryptor do its setup */
  82         setup(BF_BLOCK, context);
  83         mInitFlag = true;
  84 }
  85
  86 /*
  87  * Functions called by BlockCryptor
  88  */
  89 void BlowfishContext::encryptBlock(
  90         const void              *plainText,                     // length implied (one block)
  91         size_t                  plainTextLen,
  92         void                    *cipherText,
  93         size_t                  &cipherTextLen,         // in/out, throws on overflow
  94         bool                    final)                          // ignored
  95 {
  96         if(plainTextLen != BF_BLOCK) {
  97                 CssmError::throwMe(CSSMERR_CSP_INPUT_LENGTH_ERROR);
  98         }
  99         if(cipherTextLen < BF_BLOCK) {
 100                 CssmError::throwMe(CSSMERR_CSP_OUTPUT_LENGTH_ERROR);
 101         }
 102         BF_ecb_encrypt((const unsigned char *)plainText, (unsigned char *)cipherText,
 103                 &mBfKey, BF_ENCRYPT);
 104         cipherTextLen = BF_BLOCK;
 105 }
 106
 107 void BlowfishContext::decryptBlock(
 108         const void              *cipherText,            // length implied (one block)
 109         size_t                  cipherTextLen,
 110         void                    *plainText,
 111         size_t                  &plainTextLen,          // in/out, throws on overflow
 112         bool                    final)                          // ignored
 113 {
 114         if(plainTextLen < BF_BLOCK) {
 115                 CssmError::throwMe(CSSMERR_CSP_OUTPUT_LENGTH_ERROR);
 116         }
 117         BF_ecb_encrypt((const unsigned char *)cipherText, (unsigned char *)plainText,
 118                 &mBfKey, BF_DECRYPT);
 119         plainTextLen = BF_BLOCK;
 120 }