Security-55163.44.tar.gz

[apple/security.git] / libsecurity_apple_csp / lib / castContext.cpp

diff --git a/libsecurity_apple_csp/lib/castContext.cpp b/libsecurity_apple_csp/lib/castContext.cpp
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+++ b/libsecurity_apple_csp/lib/castContext.cpp
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+/*
+ * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
+ * 
+ * The contents of this file constitute Original Code as defined in and are
+ * subject to the Apple Public Source License Version 1.2 (the 'License').
+ * You may not use this file except in compliance with the License. Please obtain
+ * a copy of the License at http://www.apple.com/publicsource and read it before
+ * using this file.
+ * 
+ * This Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
+ * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
+ * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+ * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
+ * specific language governing rights and limitations under the License.
+ */
+
+
+/*
+ * castContext.cpp - glue between BlockCrytpor and CommonCrypto CAST128 (CAST5)
+ *                              implementation
+ *
+ */
+ 
+#include "castContext.h"
+
+CastContext::CastContext(AppleCSPSession &session) :
+    BlockCryptor(session),
+    mInitFlag(false),
+    mCastKey(NULL),
+    mRawKeySize(0)
+{
+}
+
+
+
+CastContext::~CastContext()
+{
+       deleteKey();
+}
+
+void CastContext::deleteKey()
+{
+    if (mCastKey != NULL) {
+        CCCryptorRelease(mCastKey);
+    }
+    mCastKey = NULL;
+       mInitFlag = false;
+}
+
+/* 
+ * Standard CSPContext init, called from CSPFullPluginSession::init().
+ * Reusable, e.g., query followed by en/decrypt.
+ */
+void CastContext::init( 
+       const Context &context, 
+       bool encrypting)
+{
+       if(mInitFlag && !opStarted()) {
+               return;
+       }
+
+       CSSM_SIZE       keyLen;
+       uint8           *keyData = NULL;
+       bool            sameKeySize = false;
+       
+       /* obtain key from context */
+       symmetricKeyBits(context, session(), CSSM_ALGID_CAST, 
+               encrypting ? CSSM_KEYUSE_ENCRYPT : CSSM_KEYUSE_DECRYPT,
+               keyData, keyLen);
+       if((keyLen < kCCKeySizeMinCAST) || (keyLen > kCCKeySizeMaxCAST)) {
+               CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_KEY);
+       }
+       
+       /*
+        * Delete existing key if key size changed
+        */
+       if(mRawKeySize == keyLen) {
+               sameKeySize = true;
+       }
+       else {
+               deleteKey();
+       }
+
+       /* init key only if key size or key bits have changed */
+       if(!sameKeySize || memcmp(mRawKey, keyData, mRawKeySize)) {
+        (void) CCCryptorCreateWithMode(0, kCCModeECB, kCCAlgorithmCAST, ccDefaultPadding, NULL, keyData, keyLen, NULL, 0, 0, 0, &mCastKey);
+       
+               /* save this raw key data */
+               memmove(mRawKey, keyData, keyLen); 
+               mRawKeySize = keyLen;
+       }
+       
+       /* Finally, have BlockCryptor do its setup */
+       setup(kCCBlockSizeCAST, context);
+       mInitFlag = true;
+}      
+
+/*
+ * Functions called by BlockCryptor
+ */
+void CastContext::encryptBlock(
+       const void              *plainText,                     // length implied (one block)
+       size_t                  plainTextLen,
+       void                    *cipherText,    
+       size_t                  &cipherTextLen,         // in/out, throws on overflow
+       bool                    final)                          // ignored
+{
+       if(plainTextLen != kCCBlockSizeCAST) {
+               CssmError::throwMe(CSSMERR_CSP_INPUT_LENGTH_ERROR);
+       }
+       if(cipherTextLen < kCCBlockSizeCAST) {
+               CssmError::throwMe(CSSMERR_CSP_OUTPUT_LENGTH_ERROR);
+       }
+    (void) CCCryptorEncryptDataBlock(mCastKey, NULL, plainText, kCCBlockSizeCAST, cipherText);
+
+       cipherTextLen = kCCBlockSizeCAST;
+}
+
+void CastContext::decryptBlock(
+       const void              *cipherText,            // length implied (one block)
+       size_t                  cipherTextLen,
+       void                    *plainText,     
+       size_t                  &plainTextLen,          // in/out, throws on overflow
+       bool                    final)                          // ignored
+{
+       if(plainTextLen < kCCBlockSizeCAST) {
+               CssmError::throwMe(CSSMERR_CSP_OUTPUT_LENGTH_ERROR);
+       }
+    (void) CCCryptorDecryptDataBlock(mCastKey, NULL, cipherText, kCCBlockSizeCAST, plainText);
+
+       plainTextLen = kCCBlockSizeCAST;
+}