text: /* 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://libtom.org
   */
  #include "../../headers/tomcrypt.h"
  
  /**
    @file der_decode_choice.c
    ASN.1 DER, decode a CHOICE, Tom St Denis
  */
  
  #ifdef LTC_DER
  
  /**
     Decode a CHOICE
     @param in       The DER encoded input
     @param inlen    [in/out] The size of the input and resulting size of read type
     @param list     The list of items to decode
     @param outlen   The number of items in the list
     @return CRYPT_OK on success
  */
  int der_decode_choice(const unsigned char *in,   unsigned long *inlen,
                              ltc_asn1_list *list, unsigned long  outlen)
  {
     unsigned long size, x, z;
     void          *data;
  
     LTC_ARGCHK(in    != NULL);
     LTC_ARGCHK(inlen != NULL);
     LTC_ARGCHK(list  != NULL);
  
     /* get blk size */
     if (*inlen < 2) {
        return CRYPT_INVALID_PACKET;
     }
  
     /* set all of the "used" flags to zero */
     for (x = 0; x < outlen; x++) {
         list[x].used = 0;
     }
  
     /* now scan until we have a winner */
     for (x = 0; x < outlen; x++) {
         size = list[x].size;
         data = list[x].data;
  
         switch (list[x].type) {
             case LTC_ASN1_INTEGER:
                 if (der_decode_integer(in, *inlen, data) == CRYPT_OK) {
                    if (der_length_integer(data, &z) == CRYPT_OK) {
                        list[x].used = 1;
                        *inlen       = z;
                        return CRYPT_OK;
                    }
                 }
                 break;
  
             case LTC_ASN1_SHORT_INTEGER:
                 if (der_decode_short_integer(in, *inlen, data) == CRYPT_OK) {
                    if (der_length_short_integer(size, &z) == CRYPT_OK) {
                        list[x].used = 1;
                        *inlen       = z;
                        return CRYPT_OK;
                    }
                 }
                 break;
  
             case LTC_ASN1_BIT_STRING:
                 if (der_decode_bit_string(in, *inlen, data, &size) == CRYPT_OK) {
                    if (der_length_bit_string(size, &z) == CRYPT_OK) {
                       list[x].used = 1;
                       list[x].size = size;
                       *inlen       = z;
                       return CRYPT_OK;
                    }
                 }
                 break;
  
             case LTC_ASN1_OCTET_STRING:
                 if (der_decode_octet_string(in, *inlen, data, &size) == CRYPT_OK) {
                    if (der_length_octet_string(size, &z) == CRYPT_OK) {
                       list[x].used = 1;
                       list[x].size = size;
                       *inlen       = z;
                       return CRYPT_OK;
                    }
                 }
                 break;
  
             case LTC_ASN1_NULL:
                 if (*inlen == 2 && in[x] == 0x05 && in[x+1] == 0x00) {
                    *inlen = 2;
                    list[x].used   = 1;
                    return CRYPT_OK;
                 }
                 break;
                    
             case LTC_ASN1_OBJECT_IDENTIFIER:
                 if (der_decode_object_identifier(in, *inlen, data, &size) == CRYPT_OK) {
                    if (der_length_object_identifier(data, size, &z) == CRYPT_OK) {
                       list[x].used = 1;
                       list[x].size = size;
                       *inlen       = z;
                       return CRYPT_OK;
                    }
                 }
                 break;
  
             case LTC_ASN1_IA5_STRING:
                 if (der_decode_ia5_string(in, *inlen, data, &size) == CRYPT_OK) {
                    if (der_length_ia5_string(data, size, &z) == CRYPT_OK) {
                       list[x].used = 1;
                       list[x].size = size;
                       *inlen       = z;
                       return CRYPT_OK;
                    }
                 }
                 break;
  
  
             case LTC_ASN1_PRINTABLE_STRING:
                 if (der_decode_printable_string(in, *inlen, data, &size) == CRYPT_OK) {
                    if (der_length_printable_string(data, size, &z) == CRYPT_OK) {
                       list[x].used = 1;
                       list[x].size = size;
                       *inlen       = z;
                       return CRYPT_OK;
                    }
                 }
                 break;
  
             case LTC_ASN1_UTF8_STRING:
                 if (der_decode_utf8_string(in, *inlen, data, &size) == CRYPT_OK) {
                    if (der_length_utf8_string(data, size, &z) == CRYPT_OK) {
                       list[x].used = 1;
                       list[x].size = size;
                       *inlen       = z;
                       return CRYPT_OK;
                    }
                 }
                 break;
  
             case LTC_ASN1_UTCTIME:
                 z = *inlen;
                 if (der_decode_utctime(in, &z, data) == CRYPT_OK) {
                    list[x].used = 1;
                    *inlen       = z;
                    return CRYPT_OK;
                 }
                 break;
  
             case LTC_ASN1_SET:
             case LTC_ASN1_SETOF:
             case LTC_ASN1_SEQUENCE:
                 if (der_decode_sequence(in, *inlen, data, size) == CRYPT_OK) {
                    if (der_length_sequence(data, size, &z) == CRYPT_OK) {
                       list[x].used = 1;
                       *inlen       = z;
                       return CRYPT_OK;
                    }
                 }
                 break;
  
             default:
                 return CRYPT_INVALID_ARG;
         }
     }
  
     return CRYPT_INVALID_PACKET;
  }
  
  #endif
  
  /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/choice/der_decode_choice.c,v $ */
  /* $Revision: 1.9 $ */
  /* $Date: 2006/12/28 01:27:24 $ */
  