osfmk/corecrypto/ccdigest/src/ccdigest_update.c

   1 /*
   2  *  ccdigest_update.c
   3  *  corecrypto
   4  *
   5  *  Created on 11/30/2010
   6  *
   7  *  Copyright (c) 2010,2011,2014,2015 Apple Inc. All rights reserved.
   8  *
   9  *
  10  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  11  *
  12  * This file contains Original Code and/or Modifications of Original Code
  13  * as defined in and that are subject to the Apple Public Source License
  14  * Version 2.0 (the 'License'). You may not use this file except in
  15  * compliance with the License. The rights granted to you under the License
  16  * may not be used to create, or enable the creation or redistribution of,
  17  * unlawful or unlicensed copies of an Apple operating system, or to
  18  * circumvent, violate, or enable the circumvention or violation of, any
  19  * terms of an Apple operating system software license agreement.
  20  *
  21  * Please obtain a copy of the License at
  22  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  23  *
  24  * The Original Code and all software distributed under the License are
  25  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  26  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  27  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  28  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  29  * Please see the License for the specific language governing rights and
  30  * limitations under the License.
  31  *
  32  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  33  */
  34
  35 #include <corecrypto/ccdigest.h>
  36 #include <corecrypto/cc_priv.h>
  37
  38 void ccdigest_update(const struct ccdigest_info *di, ccdigest_ctx_t ctx,
  39                      size_t len, const void *data) {
  40     const char * data_ptr = data;
  41     size_t nblocks, nbytes;
  42
  43     while (len > 0) {
  44         if (ccdigest_num(di, ctx) == 0 && len > di->block_size) {
  45             //low-end processors are slow on divison
  46             if(di->block_size == 1<<6 ){ //sha256
  47                 nblocks = len >> 6;
  48                 nbytes = len & 0xFFFFffC0;
  49             }else if(di->block_size == 1<<7 ){ //sha512
  50                 nblocks = len >> 7;
  51                 nbytes = len & 0xFFFFff80;
  52             }else {
  53                 nblocks = len / di->block_size;
  54                 nbytes = nblocks * di->block_size;
  55             }
  56
  57             di->compress(ccdigest_state(di, ctx), nblocks, data_ptr);
  58             len -= nbytes;
  59             data_ptr += nbytes;
  60             ccdigest_nbits(di, ctx) += nbytes * 8;
  61         } else {
  62             size_t n = di->block_size - ccdigest_num(di, ctx);
  63             if (len < n)
  64                 n = len;
  65             CC_MEMCPY(ccdigest_data(di, ctx) + ccdigest_num(di, ctx), data_ptr, n);
  66             /* typecast: less than block size, will always fit into an int */
  67             ccdigest_num(di, ctx) += (unsigned int)n;
  68             len -= n;
  69             data_ptr += n;
  70             if (ccdigest_num(di, ctx) == di->block_size) {
  71                 di->compress(ccdigest_state(di, ctx), 1, ccdigest_data(di, ctx));
  72                 ccdigest_nbits(di, ctx) += ccdigest_num(di, ctx) * 8;
  73                 ccdigest_num(di, ctx) = 0;
  74             }
  75         }
  76     }
  77 }