/* 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 der_length_object_identifier.c  ASN.1 DER, get length of Object Identifier, Tom St Denis*/#ifdef LTC_DERunsigned long der_object_identifier_bits(unsigned long x){   unsigned long c;   x &= 0xFFFFFFFF;   c  = 0;   while (x) {     ++c;     x >>= 1;   }   return c;}/**  Gets length of DER encoding of Object Identifier  @param nwords   The number of OID words   @param words    The actual OID words to get the size of  @param outlen   [out] The length of the DER encoding for the given string  @return CRYPT_OK if successful*/int der_length_object_identifier(unsigned long *words, unsigned long nwords, unsigned long *outlen){   unsigned long y, z, t;      LTC_ARGCHK(words  != NULL);   LTC_ARGCHK(outlen != NULL);   /* must be >= 2 words */   if (nwords < 2) {      return CRYPT_INVALID_ARG;   }   /* word1 = 0,1,2 and word2 0..39 */   if (words[0] > 2 || words[1] > 39) {      return CRYPT_INVALID_ARG;   }   /* leading byte of first two words */   z = 1;   for (y = 2; y < nwords; y++) {       t = der_object_identifier_bits(words[y]);       z += t/7 + ((t%7) ? 1 : 0);   }   /* now depending on the length our length encoding changes */   if (z < 128) {      z += 2;   } else if (z < 256) {      z += 3;   } else if (z < 65536UL) {      z += 4;   } else {      return CRYPT_INVALID_ARG;   }   *outlen = z;   return CRYPT_OK;}#endif/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/object_identifier/der_length_object_identifier.c,v $ *//* $Revision: 1.1 $ *//* $Date: 2005/05/16 15:08:11 $ */