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*/
26int hash_filehandle(int hash, FILE *in, unsigned char *out, unsigned long *outlen)
27{
28#ifdef LTC_NO_FILE
29    return CRYPT_NOP;
30#else
31    hash_state md;
32    unsigned char buf[512];
33    size_t x;
34    int err;
35
36    LTC_ARGCHK(out    != NULL);
37    LTC_ARGCHK(outlen != NULL);
38    LTC_ARGCHK(in     != NULL);
39
40    if ((err = hash_is_valid(hash)) != CRYPT_OK) {
41        return err;
42    }
43
44    if (*outlen < hash_descriptor[hash].hashsize) {
45       *outlen = hash_descriptor[hash].hashsize;
46       return CRYPT_BUFFER_OVERFLOW;
47    }
48    if ((err = hash_descriptor[hash].init(&md)) != CRYPT_OK) {
49       return err;
50    }
51
52    *outlen = hash_descriptor[hash].hashsize;
53    do {
54        x = fread(buf, 1, sizeof(buf), in);
55        if ((err = hash_descriptor[hash].process(&md, buf, x)) != CRYPT_OK) {
56           return err;
57        }
58    } while (x == sizeof(buf));
59    err = hash_descriptor[hash].done(&md, out);
60
61#ifdef LTC_CLEAN_STACK
62    zeromem(buf, sizeof(buf));
63#endif
64    return err;
65#endif
66}
67
68
69/* $Source: /cvs/libtom/libtomcrypt/src/hashes/helper/hash_filehandle.c,v $ */
70/* $Revision: 1.5 $ */
71/* $Date: 2006/06/16 21:53:41 $ */
72