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#include <stdarg.h>
13/**
14  @file hash_memory_multi.c
15  Hash (multiple buffers) memory helper, Tom St Denis
16*/
17
18/**
19  Hash multiple (non-adjacent) blocks of memory at once.
20  @param hash   The index of the hash you wish to use
21  @param out    [out] Where to store the digest
22  @param outlen [in/out] Max size and resulting size of the digest
23  @param in     The data you wish to hash
24  @param inlen  The length of the data to hash (octets)
25  @param ...    tuples of (data,len) pairs to hash, terminated with a (NULL,x) (x=don't care)
26  @return CRYPT_OK if successful
27*/
28int hash_memory_multi(int hash, unsigned char *out, unsigned long *outlen,
29                      const unsigned char *in, unsigned long inlen, ...)
30{
31    hash_state          *md;
32    int                  err;
33    va_list              args;
34    const unsigned char *curptr;
35    unsigned long        curlen;
36
37    LTC_ARGCHK(in     != NULL);
38    LTC_ARGCHK(out    != NULL);
39    LTC_ARGCHK(outlen != 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
50    md = XMALLOC(sizeof(hash_state));
51    if (md == NULL) {
52       return CRYPT_MEM;
53    }
54
55    if ((err = hash_descriptor[hash].init(md)) != CRYPT_OK) {
56       goto LBL_ERR;
57    }
58
59    va_start(args, inlen);
60    curptr = in;
61    curlen = inlen;
62    for (;;) {
63       /* process buf */
64       if ((err = hash_descriptor[hash].process(md, curptr, curlen)) != CRYPT_OK) {
65          goto LBL_ERR;
66       }
67       /* step to next */
68       curptr = va_arg(args, const unsigned char*);
69       if (curptr == NULL) {
70          break;
71       }
72       curlen = va_arg(args, unsigned long);
73    }
74    err = hash_descriptor[hash].done(md, out);
75    *outlen = hash_descriptor[hash].hashsize;
76LBL_ERR:
77#ifdef LTC_CLEAN_STACK
78    zeromem(md, sizeof(hash_state));
79#endif
80    XFREE(md);
81    va_end(args);
82    return err;
83}
84
85/* $Source: /cvs/libtom/libtomcrypt/src/hashes/helper/hash_memory_multi.c,v $ */
86/* $Revision: 1.5 $ */
87/* $Date: 2006/06/16 21:53:41 $ */
88