tomcrypt/der_get_multi_integer.c
2010-06-16 12:38:24 +02:00

51 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.
*
* Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org
*/
#include <stdarg.h>
#include "mycrypt.h"
/* will read multiple DER INTEGER encoded mp_ints from src
* of upto [inlen] bytes. It will store the number of bytes
* read back into [inlen].
*/
int der_get_multi_integer(const unsigned char *src, unsigned long *inlen,
mp_int *num, ...)
{
va_list args;
mp_int *next;
unsigned long wrote, len;
int err;
_ARGCHK(src != NULL);
_ARGCHK(inlen != NULL);
/* setup va list */
next = num;
len = *inlen;
wrote = 0;
va_start(args, num);
while (next != NULL) {
if ((err = der_decode_integer(src, inlen, next)) != CRYPT_OK) {
va_end(args);
return err;
}
wrote += *inlen;
src += *inlen;
len -= *inlen;
*inlen = len;
next = va_arg(args, mp_int*);
}
va_end(args);
*inlen = wrote;
return CRYPT_OK;
}