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/* LibTomCrypt, modular cryptographic library -- Tom St Denis
*
* LibTomCrypt is a library that provides various cryptographic
* algorithms in a highly modular and flexible manner.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
*/
#include "tomcrypt.h"
/**
@file pkcs_1_i2osp.c
Integer to Octet I2OSP, Tom St Denis
*/
#ifdef PKCS_1
/* always stores the same # of bytes, pads with leading zero bytes
as required
*/
/**
PKCS #1 Integer to binary
@param n The integer to store
@param modulus_len The length of the RSA modulus
@param out [out] The destination for the integer
@return CRYPT_OK if successful
*/
int pkcs_1_i2osp(mp_int *n, unsigned long modulus_len, unsigned char *out)
{
int err;
unsigned long size;
size = mp_unsigned_bin_size(n);
if (size > modulus_len) {
return CRYPT_BUFFER_OVERFLOW;
}
/* store it */
zeromem(out, modulus_len);
if ((err = mp_to_unsigned_bin(n, out+(modulus_len-size))) != MP_OKAY) {
return mpi_to_ltc_error(err);
}
return CRYPT_OK;
}
#endif /* PKCS_1 */
/* $Source: /cvs/libtom/libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c,v $ */
/* $Revision: 1.3 $ */
/* $Date: 2005/05/05 14:35:59 $ */
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