Security/libsecurity_apple_csp/lib/rc5Context.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  * rc5Context.cpp - glue between BlockCrytpor and ssleay RC5 implementation
  21  */
  22
  23 #include <openssl/rc5.h>
  24 #include <misc/rc5_locl.h>
  25 #include "rc5Context.h"
  26
  27 RC5Context::~RC5Context()
  28 {
  29         memset(&rc5Key, 0, sizeof(RC5_32_KEY));
  30 }
  31
  32 /*
  33  * Standard CSPContext init, called from CSPFullPluginSession::init().
  34  * Reusable, e.g., query followed by en/decrypt.
  35  */
  36 void RC5Context::init(
  37         const Context &context,
  38         bool encrypting)
  39 {
  40         CSSM_SIZE       keyLen;
  41         uint8           *keyData        = NULL;
  42         uint32          rounds = RC5_16_ROUNDS;
  43
  44         /* obtain key from context */
  45         symmetricKeyBits(context, session(), CSSM_ALGID_RC5,
  46                 encrypting ? CSSM_KEYUSE_ENCRYPT : CSSM_KEYUSE_DECRYPT,
  47                 keyData, keyLen);
  48         if((keyLen < RC5_MIN_KEY_SIZE_BYTES) || (keyLen > RC5_MAX_KEY_SIZE_BYTES)) {
  49                 CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_KEY);
  50         }
  51
  52         /*
  53          * Optional rounds
  54          */
  55         rounds = context.getInt(CSSM_ATTRIBUTE_ROUNDS);
  56         if(rounds == 0) {
  57                 /* default */
  58                 rounds = RC5_16_ROUNDS;
  59         }
  60
  61         /* init the low-level state */
  62         RC5_32_set_key(&rc5Key, (int)keyLen, keyData, rounds);
  63
  64         /* Finally, have BlockCryptor do its setup */
  65         setup(RC5_BLOCK_SIZE_BYTES, context);
  66 }
  67
  68 /*
  69  * Functions called by BlockCryptor
  70  */
  71 void RC5Context::encryptBlock(
  72         const void              *plainText,                     // length implied (one block)
  73         size_t                  plainTextLen,
  74         void                    *cipherText,
  75         size_t                  &cipherTextLen,         // in/out, throws on overflow
  76         bool                    final)                          // ignored
  77 {
  78         if(plainTextLen != RC5_BLOCK_SIZE_BYTES) {
  79                 CssmError::throwMe(CSSMERR_CSP_INPUT_LENGTH_ERROR);
  80         }
  81         if(cipherTextLen < RC5_BLOCK_SIZE_BYTES) {
  82                 CssmError::throwMe(CSSMERR_CSP_OUTPUT_LENGTH_ERROR);
  83         }
  84
  85         /*
  86          * Low-level code operates on array of unsigned 32-bit integers
  87          */
  88         RC5_32_INT      d[2];
  89         RC5_32_INT l;
  90         const unsigned char *pt = (const unsigned char *)plainText;
  91         c2l(pt, l); d[0]=l;
  92         c2l(pt, l); d[1]=l;
  93         RC5_32_encrypt(d, &rc5Key);
  94         unsigned char *ct = (unsigned char *)cipherText;
  95         l=d[0]; l2c(l, ct);
  96         l=d[1]; l2c(l, ct);
  97         cipherTextLen = RC5_BLOCK_SIZE_BYTES;
  98 }
  99
 100 void RC5Context::decryptBlock(
 101         const void              *cipherText,            // length implied (one block)
 102         size_t                  cipherTextLen,
 103         void                    *plainText,
 104         size_t                  &plainTextLen,          // in/out, throws on overflow
 105         bool                    final)                          // ignored
 106 {
 107         if(plainTextLen < RC5_BLOCK_SIZE_BYTES) {
 108                 CssmError::throwMe(CSSMERR_CSP_OUTPUT_LENGTH_ERROR);
 109         }
 110         /*
 111          * Low-level code operates on array of unsigned 32-bit integers
 112          */
 113         RC5_32_INT      d[2];
 114         RC5_32_INT l;
 115         const unsigned char *ct = (const unsigned char *)cipherText;
 116         c2l(ct, l); d[0]=l;
 117         c2l(ct, l); d[1]=l;
 118         RC5_32_decrypt(d, &rc5Key);
 119         unsigned char *pt = (unsigned char *)plainText;
 120         l=d[0]; l2c(l, pt);
 121         l=d[1]; l2c(l, pt);
 122         plainTextLen = RC5_BLOCK_SIZE_BYTES;
 123 }
 124