core/BER.hh

   1 /******************************************************************************
   2  * Copyright (c) 2000-2016 Ericsson Telecom AB
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Eclipse Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/epl-v10.html
   7  *
   8  * Contributors:
   9  *   Balasko, Jeno
  10  *   Forstner, Matyas
  11  *   Raduly, Csaba
  12  *   Szabo, Janos Zoltan – initial implementation
  13  *
  14  ******************************************************************************/
  15 #ifndef _BER_HH
  16 #define _BER_HH
  17
  18 /** @name BER encoding subtypes
  19     @{
  20 */
  21 /// Canonical Encoding Rules
  22 #define BER_ENCODE_CER 1
  23 /// Distinguished Encoding Rules
  24 #define BER_ENCODE_DER 2
  25 /** @} */
  26
  27 /** @name BER decoding options
  28     @{
  29 */
  30 /// Short length form is acceptable
  31 #define BER_ACCEPT_SHORT 0x01
  32 /// Long length form is acceptable
  33 #define BER_ACCEPT_LONG 0x02
  34 /// Indefinite form is acceptable
  35 #define BER_ACCEPT_INDEFINITE 0x04
  36 /// Definite forms (short or long) are acceptable
  37 #define BER_ACCEPT_DEFINITE 0x03
  38 /// All forms are acceptable
  39 #define BER_ACCEPT_ALL 0x07
  40 /** @} */
  41
  42 #include "Types.h"
  43 #include "Encdec.hh"
  44
  45 /**
  46   * \defgroup BER BER-related stuff.
  47   *
  48   *  @{
  49   */
  50
  51 /** @brief ASN.1 tag */
  52 enum ASN_Tagclass_t {
  53   ASN_TAG_UNDEF,
  54   ASN_TAG_UNIV, /**< UNIVERSAL */
  55   ASN_TAG_APPL, /**< APPLICATION */
  56   ASN_TAG_CONT, /**< context-specific */
  57   ASN_TAG_PRIV  /**< PRIVATE */
  58 };
  59
  60 typedef unsigned int ASN_Tagnumber_t;
  61
  62 /** @brief ASN.1 identifier
  63   *
  64   * Contains two thirds of the T from a TLV
  65   */
  66 struct ASN_Tag_t {
  67   ASN_Tagclass_t tagclass; /**< Tag class */
  68   ASN_Tagnumber_t tagnumber; /**< Tag value. For UNIVERSAL, the values are predefined */
  69
  70   /** Creates a user-friendly representation of the tag. After using,
  71     * you have to Free() this string. */
  72   char* print() const;
  73 };
  74
  75 /** @brief BER encoding information
  76  *
  77  * There is one object for each predefined (UNIVERSAL) type.
  78  * Also, the compiler writes an object of this type for each user-defined type
  79  * into the generated code in Common::Type::generate_code_berdescriptor() .
  80  */
  81 struct ASN_BERdescriptor_t {
  82   /** Number of tags.
  83    *
  84    *  For the UNIVERSAL classes, this is usually 1 (except for CHOICE and ANY)
  85    */
  86   size_t n_tags;
  87   /** This array contains the tags. Index 0 is the innermost tag. */
  88   const ASN_Tag_t *tags;
  89
  90   /** Creates a user-friendly representation of tags. After using, you
  91     * have to Free() this string. */
  92   char* print_tags() const;
  93 };
  94
  95 struct TTCN_Typedescriptor_t;
  96
  97 extern const ASN_BERdescriptor_t BOOLEAN_ber_;
  98 extern const ASN_BERdescriptor_t INTEGER_ber_;
  99 extern const ASN_BERdescriptor_t BITSTRING_ber_;
 100 extern const ASN_BERdescriptor_t OCTETSTRING_ber_;
 101 extern const ASN_BERdescriptor_t ASN_NULL_ber_;
 102 extern const ASN_BERdescriptor_t OBJID_ber_;
 103 extern const ASN_BERdescriptor_t ObjectDescriptor_ber_;
 104 extern const ASN_BERdescriptor_t FLOAT_ber_;
 105 extern const ASN_BERdescriptor_t ENUMERATED_ber_;
 106 extern const ASN_BERdescriptor_t UTF8String_ber_;
 107 extern const ASN_BERdescriptor_t ASN_ROID_ber_;
 108 extern const ASN_BERdescriptor_t SEQUENCE_ber_;
 109 extern const ASN_BERdescriptor_t SET_ber_;
 110 extern const ASN_BERdescriptor_t CHOICE_ber_;
 111 extern const ASN_BERdescriptor_t ASN_ANY_ber_;
 112 extern const ASN_BERdescriptor_t NumericString_ber_;
 113 extern const ASN_BERdescriptor_t PrintableString_ber_;
 114 extern const ASN_BERdescriptor_t TeletexString_ber_;
 115 extern const ASN_BERdescriptor_t VideotexString_ber_;
 116 extern const ASN_BERdescriptor_t IA5String_ber_;
 117 extern const ASN_BERdescriptor_t ASN_UTCTime_ber_;
 118 extern const ASN_BERdescriptor_t ASN_GeneralizedTime_ber_;
 119 extern const ASN_BERdescriptor_t GraphicString_ber_;
 120 extern const ASN_BERdescriptor_t VisibleString_ber_;
 121 extern const ASN_BERdescriptor_t GeneralString_ber_;
 122 extern const ASN_BERdescriptor_t UniversalString_ber_;
 123 extern const ASN_BERdescriptor_t BMPString_ber_;
 124 extern const ASN_BERdescriptor_t EXTERNAL_ber_;
 125 extern const ASN_BERdescriptor_t EMBEDDED_PDV_ber_;
 126 extern const ASN_BERdescriptor_t CHARACTER_STRING_ber_;
 127
 128 /** An unsigned long long with 7 bits set (0x7F) in the most significant byte.
 129  *  Used when decoding objid values. */
 130 extern const unsigned long long unsigned_llong_7msb;
 131
 132 /** An unsigned long with 8 bits set (0xFF) in the most significant byte.
 133  *  Used when decoding integers. */
 134 extern const unsigned long unsigned_long_8msb;
 135
 136 /** How many bits are needed minimally to represent the given
 137   * (nonnegative integral) value. Returned value is greater than or
 138   * equal to 1. */
 139 template<typename T>
 140 size_t min_needed_bits(T p)
 141 {
 142   if(p==0) return 1;
 143   register size_t n=0;
 144   register T tmp=p;
 145   while(tmp!=0) n++, tmp/=2;
 146   return n;
 147 }
 148
 149 /** This struct represents a BER TLV.
 150  *
 151  * It represents a "deconstructed" (cooked) representation of
 152  * a BER encoding. */
 153 struct ASN_BER_TLV_t {
 154   boolean isConstructed;   /**< Primitive/Constructed bit. */
 155   boolean V_tlvs_selected; /**< How the data is stored in \p V. */
 156   boolean isLenDefinite;   /**< \c false for indefinite form */
 157   boolean isLenShort;      /**< \c true for short form (0-127) */
 158   /** Is \p tagclass and \p tagnumber valid.
 159    *  ASN_BER_str2TLV function sets this. */
 160   boolean isTagComplete;
 161   boolean isComplete;
 162   ASN_Tagclass_t tagclass; /**< UNIV/APP/context/PRIVATE */
 163   ASN_Tagnumber_t tagnumber;
 164   size_t Tlen; /** Length of T part. May be >1 for tag values >30 */
 165   size_t Llen; /** Length of L part. */
 166   unsigned char *Tstr; /** Encoded T part. */
 167   unsigned char *Lstr; /** Encoded L part. */
 168   union { /* depends on V_tlvs_selected */
 169     struct {
 170       size_t Vlen;
 171       unsigned char *Vstr;
 172     } str; /**< V_tlvs_selected==FALSE */
 173     struct {
 174       size_t n_tlvs;
 175       ASN_BER_TLV_t **tlvs;
 176     } tlvs; /**< V_tlvs_selected==TRUE */
 177   } V;
 178
 179   /** Creates a new constructed TLV which contains one TLV (\a
 180     * p_tlv). Or, if the parameter is NULL, then an empty constructed
 181     * TLV is created. */
 182   static ASN_BER_TLV_t* construct(ASN_BER_TLV_t *p_tlv);
 183   /** Creates a new non-constructed TLV with the given V-part.
 184     * Tagclass and -number are set to UNIV-0. If \a p_Vstr is NULL
 185     * then allocates a \a p_Vlen size buffer for Vstr.
 186     * Takes over ownership of \a p_Vstr */
 187   static ASN_BER_TLV_t* construct(size_t p_Vlen, unsigned char *p_Vstr);
 188   /** Creates a new non-constructed TLV with empty T, L and V part. */
 189   static ASN_BER_TLV_t* construct();
 190   /** Frees the given \a p_tlv recursively. Tstr, Lstr and
 191     * Vstr/tlvs. If \a no_str is TRUE, then only the tlvs are deleted,
 192     * the strings (Tstr, Lstr, Vstr) are not. This is useful during
 193     * decoding, when the Xstr points into a buffer.*/
 194   static void destruct(ASN_BER_TLV_t *p_tlv, boolean no_str=FALSE);
 195   /** Checks the 'constructed' flag. If fails, raises an EncDec
 196     * error. */
 197   void chk_constructed_flag(boolean flag_expected) const;
 198   /** Adds \a p_tlv to this (constructed) TLV.
 199    * @pre isConstructed   is \c true
 200    * @pre V_tlvs_selected is \c true */
 201   void add_TLV(ASN_BER_TLV_t *p_tlv);
 202   /** Adds a new UNIVERSAL 0 TLV to this (constructed) TLV. */
 203   void add_UNIV0_TLV();
 204   /** Returns the length (in bytes) of the full TLV. */
 205   size_t get_len() const;
 206   /** Adds T and L part to TLV. It adds trailing UNI-0 TLV (two zero
 207     * octets) if the length form is indefinite. Precondition:
 208     * isConstructed (and V_tlvs_selected) and V-part are valid. */
 209   void add_TL(ASN_Tagclass_t p_tagclass,
 210               ASN_Tagnumber_t p_tagnumber,
 211               unsigned coding);
 212   /** Puts the TLV in buffer \a p_buf. */
 213   void put_in_buffer(TTCN_Buffer& p_buf);
 214   /** Gets the octet in position \a pos. Works also for constructed TLVs. */
 215   unsigned char get_pos(size_t pos) const;
 216 private:
 217   unsigned char _get_pos(size_t& pos, boolean& success) const;
 218 public:
 219   /** Compares the TLVs as described in X.690 11.6. Returns -1 if this
 220     * less than, 0 if equal to, 1 if greater than other. */
 221   int compare(const ASN_BER_TLV_t *other) const;
 222   /** Sorts its TLVs according to their octetstring representation, as
 223     * described in X.690 11.6. */
 224   void sort_tlvs();
 225   /** Compares the TLVs according their tags as described in X.680
 226     * 8.6. Returns -1 if this less than, 0 if equal to, 1 if greater
 227     * than other. */
 228   int compare_tags(const ASN_BER_TLV_t *other) const;
 229   /** Sorts its TLVs according to their tags, as described in X.690
 230     * 10.3. */
 231   void sort_tlvs_tag();
 232 };
 233
 234 /**
 235   * Searches the T, L and V parts of the TLV represented in \a s, and
 236   * stores it in \a tlv. Returns FALSE if there isn't a complete
 237   * TLV-structure in \a s, TRUE otherwise.
 238   */
 239 boolean ASN_BER_str2TLV(size_t p_len_s,
 240                         const unsigned char* p_str,
 241                         ASN_BER_TLV_t& tlv,
 242                         unsigned L_form);
 243
 244 /**
 245   * Adds the T and L part of the TLV. If there are multiple tags, then
 246   * adds them all. Precondition: the following fields are ready of \a
 247   * p_tlv: isConstructed, V_tlvs_selected, isLenDefinite, isLenShort
 248   * and V. If tagclass and tagnumber are UNIVERSAL 0, then replaces
 249   * them, otherwise 'wraps' p_tlv in a new TLV.
 250   */
 251 ASN_BER_TLV_t* ASN_BER_V2TLV(ASN_BER_TLV_t* p_tlv,
 252                              const TTCN_Typedescriptor_t& p_td,
 253                              unsigned coding);
 254
 255 /** @} end of BER group */
 256
 257 #endif // _BER_HH