/* 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.com */#include "tomcrypt.h"/**  @file der_encode_setof.c  ASN.1 DER, Encode SET OF, Tom St Denis*/#ifdef LTC_DERstruct edge {   unsigned char *start;   unsigned long  size;};static int qsort_helper(const void *a, const void *b){   struct edge   *A = (struct edge *)a, *B = (struct edge *)b;   int            r;   unsigned long  x;      /* compare min length */   r = XMEMCMP(A->start, B->start, MIN(A->size, B->size));      if (r == 0 && A->size != B->size) {      if (A->size > B->size) {         for (x = B->size; x < A->size; x++) {            if (A->start[x]) {               return 1;            }         }      } else {         for (x = A->size; x < B->size; x++) {            if (B->start[x]) {               return -1;            }         }      }            }      return r;      }/**   Encode a SETOF stucture   @param list      The list of items to encode   @param inlen     The number of items in the list   @param out       [out] The destination    @param outlen    [in/out] The size of the output   @return CRYPT_OK on success*/   int der_encode_setof(ltc_asn1_list *list, unsigned long inlen,                     unsigned char *out,  unsigned long *outlen){   unsigned long  x, y, z, hdrlen;   int            err;   struct edge   *edges;   unsigned char *ptr, *buf;      /* check that they're all the same type */   for (x = 1; x < inlen; x++) {      if (list[x].type != list[x-1].type) {         return CRYPT_INVALID_ARG;      }   }   /* alloc buffer to store copy of output */   buf = XCALLOC(1, *outlen);   if (buf == NULL) {      return CRYPT_MEM;   }                           /* encode list */   if ((err = der_encode_sequence_ex(list, inlen, buf, outlen, LTC_ASN1_SETOF)) != CRYPT_OK) {       XFREE(buf);       return err;   }      /* allocate edges */   edges = XCALLOC(inlen, sizeof(*edges));   if (edges == NULL) {      XFREE(buf);      return CRYPT_MEM;   }            /* skip header */      ptr = buf + 1;      /* now skip length data */      x = *ptr++;      if (x >= 0x80) {         ptr += (x & 0x7F);      }            /* get the size of the static header */      hdrlen = ((unsigned long)ptr) - ((unsigned long)buf);               /* scan for edges */   x = 0;   while (ptr < (buf + *outlen)) {      /* store start */      edges[x].start = ptr;            /* skip type */      z = 1;            /* parse length */      y = ptr[z++];      if (y < 128) {         edges[x].size = y;      } else {         y &= 0x7F;         edges[x].size = 0;         while (y--) {            edges[x].size = (edges[x].size << 8) | ((unsigned long)ptr[z++]);         }      }            /* skip content */      edges[x].size += z;      ptr           += edges[x].size;      ++x;   }               /* sort based on contents (using edges) */   XQSORT(edges, inlen, sizeof(*edges), &qsort_helper);      /* copy static header */   XMEMCPY(out, buf, hdrlen);      /* copy+sort using edges+indecies to output from buffer */   for (y = hdrlen, x = 0; x < inlen; x++) {      XMEMCPY(out+y, edges[x].start, edges[x].size);      y += edges[x].size;   }         #ifdef LTC_CLEAN_STACK   zeromem(buf, *outlen);#endif            /* free buffers */   XFREE(edges);   XFREE(buf);      return CRYPT_OK;}#endif/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/set/der_encode_setof.c,v $ *//* $Revision: 1.11 $ *//* $Date: 2006/03/31 14:15:35 $ */