50 lines
1.2 KiB
C

/* 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.
*/
#include "tomcrypt.h"
/**
@file pkcs_1_i2osp.c
Integer to Octet I2OSP, Tom St Denis
*/
#ifdef LTC_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(void *n, unsigned long modulus_len, unsigned char *out)
{
unsigned long size;
size = mp_unsigned_bin_size(n);
if (size > modulus_len) {
return CRYPT_BUFFER_OVERFLOW;
}
/* store it */
zeromem(out, modulus_len);
return mp_to_unsigned_bin(n, out+(modulus_len-size));
}
#endif /* LTC_PKCS_1 */
/* ref: HEAD -> master, tag: v1.18.2 */
/* git commit: 7e7eb695d581782f04b24dc444cbfde86af59853 */
/* commit time: 2018-07-01 22:49:01 +0200 */