OSX/libsecurity_apple_csp/lib/castContext.cpp

   1 /*
   2  * Copyright (c) 2000-2001,2011-2012,2014 Apple 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.cpp - glue between BlockCrytpor and CommonCrypto CAST128 (CAST5)
  21  *                               implementation
  22  *
  23  */
  24
  25 #include "castContext.h"
  26
  27 CastContext::CastContext(AppleCSPSession &session) :
  28     BlockCryptor(session),
  29     mCastKey(NULL),
  30     mInitFlag(false),
  31     mRawKeySize(0)
  32 {
  33 }
  34
  35
  36
  37 CastContext::~CastContext()
  38 {
  39         deleteKey();
  40 }
  41
  42 void CastContext::deleteKey()
  43 {
  44     if (mCastKey != NULL) {
  45         CCCryptorRelease(mCastKey);
  46     }
  47     mCastKey = NULL;
  48         mInitFlag = false;
  49 }
  50
  51 /*
  52  * Standard CSPContext init, called from CSPFullPluginSession::init().
  53  * Reusable, e.g., query followed by en/decrypt.
  54  */
  55 void CastContext::init(
  56         const Context &context,
  57         bool encrypting)
  58 {
  59         if(mInitFlag && !opStarted()) {
  60                 return;
  61         }
  62
  63         CSSM_SIZE       keyLen;
  64         uint8           *keyData = NULL;
  65         bool            sameKeySize = false;
  66
  67         /* obtain key from context */
  68         symmetricKeyBits(context, session(), CSSM_ALGID_CAST,
  69                 encrypting ? CSSM_KEYUSE_ENCRYPT : CSSM_KEYUSE_DECRYPT,
  70                 keyData, keyLen);
  71         if((keyLen < kCCKeySizeMinCAST) || (keyLen > kCCKeySizeMaxCAST)) {
  72                 CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_KEY);
  73         }
  74
  75         /*
  76          * Delete existing key if key size changed
  77          */
  78         if(mRawKeySize == keyLen) {
  79                 sameKeySize = true;
  80         }
  81         else {
  82                 deleteKey();
  83         }
  84
  85         /* init key only if key size or key bits have changed */
  86         if(!sameKeySize || memcmp(mRawKey, keyData, mRawKeySize)) {
  87         (void) CCCryptorCreateWithMode(0, kCCModeECB, kCCAlgorithmCAST, ccDefaultPadding, NULL, keyData, keyLen, NULL, 0, 0, 0, &mCastKey);
  88
  89                 /* save this raw key data */
  90                 memmove(mRawKey, keyData, keyLen);
  91                 mRawKeySize = (uint32)keyLen;
  92         }
  93
  94         /* Finally, have BlockCryptor do its setup */
  95         setup(kCCBlockSizeCAST, context);
  96         mInitFlag = true;
  97 }
  98
  99 /*
 100  * Functions called by BlockCryptor
 101  */
 102 void CastContext::encryptBlock(
 103         const void              *plainText,                     // length implied (one block)
 104         size_t                  plainTextLen,
 105         void                    *cipherText,
 106         size_t                  &cipherTextLen,         // in/out, throws on overflow
 107         bool                    final)                          // ignored
 108 {
 109         if(plainTextLen != kCCBlockSizeCAST) {
 110                 CssmError::throwMe(CSSMERR_CSP_INPUT_LENGTH_ERROR);
 111         }
 112         if(cipherTextLen < kCCBlockSizeCAST) {
 113                 CssmError::throwMe(CSSMERR_CSP_OUTPUT_LENGTH_ERROR);
 114         }
 115     (void) CCCryptorEncryptDataBlock(mCastKey, NULL, plainText, kCCBlockSizeCAST, cipherText);
 116
 117         cipherTextLen = kCCBlockSizeCAST;
 118 }
 119
 120 void CastContext::decryptBlock(
 121         const void              *cipherText,            // length implied (one block)
 122         size_t                  cipherTextLen,
 123         void                    *plainText,
 124         size_t                  &plainTextLen,          // in/out, throws on overflow
 125         bool                    final)                          // ignored
 126 {
 127         if(plainTextLen < kCCBlockSizeCAST) {
 128                 CssmError::throwMe(CSSMERR_CSP_OUTPUT_LENGTH_ERROR);
 129         }
 130     (void) CCCryptorDecryptDataBlock(mCastKey, NULL, cipherText, kCCBlockSizeCAST, plainText);
 131
 132         plainTextLen = kCCBlockSizeCAST;
 133 }