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
  39 ccdigest_update(const struct ccdigest_info *di, ccdigest_ctx_t ctx,
  40     size_t len, const void *data)
  41 {
  42         const char * data_ptr = data;
  43         size_t nblocks, nbytes;
  44
  45         while (len > 0) {
  46                 if (ccdigest_num(di, ctx) == 0 && len > di->block_size) {
  47                         //low-end processors are slow on divison
  48                         if (di->block_size == 1 << 6) { //sha256
  49                                 nblocks = len >> 6;
  50                                 nbytes = len & 0xFFFFffC0;
  51                         } else if (di->block_size == 1 << 7) { //sha512
  52                                 nblocks = len >> 7;
  53                                 nbytes = len & 0xFFFFff80;
  54                         } else {
  55                                 nblocks = len / di->block_size;
  56                                 nbytes = nblocks * di->block_size;
  57                         }
  58
  59                         di->compress(ccdigest_state(di, ctx), nblocks, data_ptr);
  60                         len -= nbytes;
  61                         data_ptr += nbytes;
  62                         ccdigest_nbits(di, ctx) += nbytes * 8;
  63                 } else {
  64                         size_t n = di->block_size - ccdigest_num(di, ctx);
  65                         if (len < n) {
  66                                 n = len;
  67                         }
  68                         CC_MEMCPY(ccdigest_data(di, ctx) + ccdigest_num(di, ctx), data_ptr, n);
  69                         /* typecast: less than block size, will always fit into an int */
  70                         ccdigest_num(di, ctx) += (unsigned int)n;
  71                         len -= n;
  72                         data_ptr += n;
  73                         if (ccdigest_num(di, ctx) == di->block_size) {
  74                                 di->compress(ccdigest_state(di, ctx), 1, ccdigest_data(di, ctx));
  75                                 ccdigest_nbits(di, ctx) += ccdigest_num(di, ctx) * 8;
  76                                 ccdigest_num(di, ctx) = 0;
  77                         }
  78                 }
  79         }
  80 }