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 pkcs_1_i2osp.c
15  Integer to Octet I2OSP, Tom St Denis
16*/
17
18#ifdef PKCS_1
19
20/* always stores the same # of bytes, pads with leading zero bytes
21   as required
22 */
23
24/**
25   PKCS #1 Integer to binary
26   @param n             The integer to store
27   @param modulus_len   The length of the RSA modulus
28   @param out           [out] The destination for the integer
29   @return CRYPT_OK if successful
30*/
31int pkcs_1_i2osp(void *n, unsigned long modulus_len, unsigned char *out)
32{
33   unsigned long size;
34
35   size = mp_unsigned_bin_size(n);
36
37   if (size > modulus_len) {
38      return CRYPT_BUFFER_OVERFLOW;
39   }
40
41   /* store it */
42   zeromem(out, modulus_len);
43   return mp_to_unsigned_bin(n, out+(modulus_len-size));
44}
45
46#endif /* PKCS_1 */
47
48
49/* $Source: /cvs/libtom/libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c,v $ */
50/* $Revision: 1.5 $ */
51/* $Date: 2006/03/31 14:15:35 $ */
52