release/src/router/dropbear/libtomcrypt/src/hashes/helper/hash_filehandle.c

   1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
   2  *
   3  * LibTomCrypt is a library that provides various cryptographic
   4  * algorithms in a highly modular and flexible manner.
   5  *
   6  * The library is free for all purposes without any express
   7  * guarantee it works.
   8  *
   9  * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
  10  */
  11 #include "tomcrypt.h"
  12
  13 /**
  14    @file hash_filehandle.c
  15    Hash open files, Tom St Denis
  16 */
  17
  18 /**
  19   Hash data from an open file handle.
  20   @param hash   The index of the hash you want to use
  21   @param in     The FILE* handle of the file you want to hash
  22   @param out    [out] The destination of the digest
  23   @param outlen [in/out] The max size and resulting size of the digest
  24   @result CRYPT_OK if successful
  25 */
  26 int hash_filehandle(int hash, FILE *in, unsigned char *out, unsigned long *outlen)
  27 {
  28 #ifdef LTC_NO_FILE
  29     (void)hash; (void)in; (void)out; (void)outlen;
  30     return CRYPT_NOP;
  31 #else
  32     hash_state md;
  33     unsigned char buf[512];
  34     size_t x;
  35     int err;
  36
  37     LTC_ARGCHK(out    != NULL);
  38     LTC_ARGCHK(outlen != NULL);
  39     LTC_ARGCHK(in     != NULL);
  40
  41     if ((err = hash_is_valid(hash)) != CRYPT_OK) {
  42         return err;
  43     }
  44
  45     if (*outlen < hash_descriptor[hash].hashsize) {
  46        *outlen = hash_descriptor[hash].hashsize;
  47        return CRYPT_BUFFER_OVERFLOW;
  48     }
  49     if ((err = hash_descriptor[hash].init(&md)) != CRYPT_OK) {
  50        return err;
  51     }
  52
  53     *outlen = hash_descriptor[hash].hashsize;
  54     do {
  55         x = fread(buf, 1, sizeof(buf), in);
  56         if ((err = hash_descriptor[hash].process(&md, buf, x)) != CRYPT_OK) {
  57            return err;
  58         }
  59     } while (x == sizeof(buf));
  60     err = hash_descriptor[hash].done(&md, out);
  61
  62 #ifdef LTC_CLEAN_STACK
  63     zeromem(buf, sizeof(buf));
  64 #endif
  65     return err;
  66 #endif
  67 }
  68
  69
  70 /* $Source: /cvs/libtom/libtomcrypt/src/hashes/helper/hash_filehandle.c,v $ */
  71 /* $Revision: 1.5 $ */
  72 /* $Date: 2006/06/16 21:53:41 $ */