| /* 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 <stdarg.h> |
| #include "tomcrypt.h" |
| |
| /** |
| @file der_get_multi_integer.c |
| ASN.1 DER, read multiple integers, Tom St Denis |
| */ |
| |
| |
| #ifdef LTC_DER |
| |
| /* 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]. |
| */ |
| /** |
| Read multiple mp_int integers one after another |
| @param src The DER encoded integers |
| @param inlen [in] The length of the src buffer, [out] the amount of bytes read |
| @param num The first mp_int to decode |
| @param ... A NULL terminated list of mp_ints to decode |
| @return CRYPT_OK if successful |
| */ |
| 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; |
| |
| LTC_ARGCHK(src != NULL); |
| LTC_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; |
| } |
| |
| #endif |