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
  11 #include <corecrypto/ccdigest.h>
  12 #include <corecrypto/cc_priv.h>
  13
  14 void ccdigest_update(const struct ccdigest_info *di, ccdigest_ctx_t ctx,
  15                      unsigned long len, const void *data) {
  16     const char * data_ptr = data;
  17     while (len > 0) {
  18         if (ccdigest_num(di, ctx) == 0 && len > di->block_size) {
  19             unsigned long nblocks = len / di->block_size;
  20             di->compress(ccdigest_state(di, ctx), nblocks, data_ptr);
  21             unsigned long nbytes = nblocks * di->block_size;
  22             len -= nbytes;
  23             data_ptr += nbytes;
  24             ccdigest_nbits(di, ctx) += nbytes * 8;
  25         } else {
  26             unsigned long n = di->block_size - ccdigest_num(di, ctx);
  27             if (len < n)
  28                 n = len;
  29             CC_MEMCPY(ccdigest_data(di, ctx) + ccdigest_num(di, ctx), data_ptr, n);
  30             /* typecast: less than block size, will always fit into an int */
  31             ccdigest_num(di, ctx) += (unsigned int)n;
  32             len -= n;
  33             data_ptr += n;
  34             if (ccdigest_num(di, ctx) == di->block_size) {
  35                 di->compress(ccdigest_state(di, ctx), 1, ccdigest_data(di, ctx));
  36                 ccdigest_nbits(di, ctx) += ccdigest_num(di, ctx) * 8;
  37                 ccdigest_num(di, ctx) = 0;
  38             }
  39         }
  40     }
  41 }