core/BER.hh

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Copyright (c) 2000-2014 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 #ifndef _BER_HH
   9 #define _BER_HH
  10
  11 /** @name BER encoding subtypes
  12     @{
  13 */
  14 /// Canonical Encoding Rules
  15 #define BER_ENCODE_CER 1
  16 /// Distinguished Encoding Rules
  17 #define BER_ENCODE_DER 2
  18 /** @} */
  19
  20 /** @name BER decoding options
  21     @{
  22 */
  23 /// Short length form is acceptable
  24 #define BER_ACCEPT_SHORT 0x01
  25 /// Long length form is acceptable
  26 #define BER_ACCEPT_LONG 0x02
  27 /// Indefinite form is acceptable
  28 #define BER_ACCEPT_INDEFINITE 0x04
  29 /// Definite forms (short or long) are acceptable
  30 #define BER_ACCEPT_DEFINITE 0x03
  31 /// All forms are acceptable
  32 #define BER_ACCEPT_ALL 0x07
  33 /** @} */
  34
  35 #include "Types.h"
  36 #include "Encdec.hh"
  37
  38 /**
  39   * \defgroup BER BER-related stuff.
  40   *
  41   *  @{
  42   */
  43
  44 /** @brief ASN.1 tag */
  45 enum ASN_Tagclass_t {
  46   ASN_TAG_UNDEF,
  47   ASN_TAG_UNIV, /**< UNIVERSAL */
  48   ASN_TAG_APPL, /**< APPLICATION */
  49   ASN_TAG_CONT, /**< context-specific */
  50   ASN_TAG_PRIV  /**< PRIVATE */
  51 };
  52
  53 typedef unsigned int ASN_Tagnumber_t;
  54
  55 /** @brief ASN.1 identifier
  56   *
  57   * Contains two thirds of the T from a TLV
  58   */
  59 struct ASN_Tag_t {
  60   ASN_Tagclass_t tagclass; /**< Tag class */
  61   ASN_Tagnumber_t tagnumber; /**< Tag value. For UNIVERSAL, the values are predefined */
  62
  63   /** Creates a user-friendly representation of the tag. After using,
  64     * you have to Free() this string. */
  65   char* print() const;
  66 };
  67
  68 /** @brief BER encoding information
  69  *
  70  * There is one object for each predefined (UNIVERSAL) type.
  71  * Also, the compiler writes an object of this type for each user-defined type
  72  * into the generated code in Common::Type::generate_code_berdescriptor() .
  73  */
  74 struct ASN_BERdescriptor_t {
  75   /** Number of tags.
  76    *
  77    *  For the UNIVERSAL classes, this is usually 1 (except for CHOICE and ANY)
  78    */
  79   size_t n_tags;
  80   /** This array contains the tags. Index 0 is the innermost tag. */
  81   const ASN_Tag_t *tags;
  82
  83   /** Creates a user-friendly representation of tags. After using, you
  84     * have to Free() this string. */
  85   char* print_tags() const;
  86 };
  87
  88 struct TTCN_Typedescriptor_t;
  89
  90 extern const ASN_BERdescriptor_t BOOLEAN_ber_;
  91 extern const ASN_BERdescriptor_t INTEGER_ber_;
  92 extern const ASN_BERdescriptor_t BITSTRING_ber_;
  93 extern const ASN_BERdescriptor_t OCTETSTRING_ber_;
  94 extern const ASN_BERdescriptor_t ASN_NULL_ber_;
  95 extern const ASN_BERdescriptor_t OBJID_ber_;
  96 extern const ASN_BERdescriptor_t ObjectDescriptor_ber_;
  97 extern const ASN_BERdescriptor_t FLOAT_ber_;
  98 extern const ASN_BERdescriptor_t ENUMERATED_ber_;
  99 extern const ASN_BERdescriptor_t UTF8String_ber_;
 100 extern const ASN_BERdescriptor_t ASN_ROID_ber_;
 101 extern const ASN_BERdescriptor_t SEQUENCE_ber_;
 102 extern const ASN_BERdescriptor_t SET_ber_;
 103 extern const ASN_BERdescriptor_t CHOICE_ber_;
 104 extern const ASN_BERdescriptor_t ASN_ANY_ber_;
 105 extern const ASN_BERdescriptor_t NumericString_ber_;
 106 extern const ASN_BERdescriptor_t PrintableString_ber_;
 107 extern const ASN_BERdescriptor_t TeletexString_ber_;
 108 extern const ASN_BERdescriptor_t VideotexString_ber_;
 109 extern const ASN_BERdescriptor_t IA5String_ber_;
 110 extern const ASN_BERdescriptor_t ASN_UTCTime_ber_;
 111 extern const ASN_BERdescriptor_t ASN_GeneralizedTime_ber_;
 112 extern const ASN_BERdescriptor_t GraphicString_ber_;
 113 extern const ASN_BERdescriptor_t VisibleString_ber_;
 114 extern const ASN_BERdescriptor_t GeneralString_ber_;
 115 extern const ASN_BERdescriptor_t UniversalString_ber_;
 116 extern const ASN_BERdescriptor_t BMPString_ber_;
 117 extern const ASN_BERdescriptor_t EXTERNAL_ber_;
 118 extern const ASN_BERdescriptor_t EMBEDDED_PDV_ber_;
 119 extern const ASN_BERdescriptor_t CHARACTER_STRING_ber_;
 120
 121 /** An unsigned long long with 7 bits set (0x7F) in the most significant byte.
 122  *  Used when decoding objid values. */
 123 extern const unsigned long long unsigned_llong_7msb;
 124
 125 /** An unsigned long with 8 bits set (0xFF) in the most significant byte.
 126  *  Used when decoding integers. */
 127 extern const unsigned long unsigned_long_8msb;
 128
 129 /** How many bits are needed minimally to represent the given
 130   * (nonnegative integral) value. Returned value is greater than or
 131   * equal to 1. */
 132 template<typename T>
 133 size_t min_needed_bits(T p)
 134 {
 135   if(p==0) return 1;
 136   register size_t n=0;
 137   register T tmp=p;
 138   while(tmp!=0) n++, tmp/=2;
 139   return n;
 140 }
 141
 142 /** This struct represents a BER TLV.
 143  *
 144  * It represents a "deconstructed" (cooked) representation of
 145  * a BER encoding. */
 146 struct ASN_BER_TLV_t {
 147   boolean isConstructed;   /**< Primitive/Constructed bit. */
 148   boolean V_tlvs_selected; /**< How the data is stored in \p V. */
 149   boolean isLenDefinite;   /**< \c false for indefinite form */
 150   boolean isLenShort;      /**< \c true for short form (0-127) */
 151   /** Is \p tagclass and \p tagnumber valid.
 152    *  ASN_BER_str2TLV function sets this. */
 153   boolean isTagComplete;
 154   boolean isComplete;
 155   ASN_Tagclass_t tagclass; /**< UNIV/APP/context/PRIVATE */
 156   ASN_Tagnumber_t tagnumber;
 157   size_t Tlen; /** Length of T part. May be >1 for tag values >30 */
 158   size_t Llen; /** Length of L part. */
 159   unsigned char *Tstr; /** Encoded T part. */
 160   unsigned char *Lstr; /** Encoded L part. */
 161   union { /* depends on V_tlvs_selected */
 162     struct {
 163       size_t Vlen;
 164       unsigned char *Vstr;
 165     } str; /**< V_tlvs_selected==FALSE */
 166     struct {
 167       size_t n_tlvs;
 168       ASN_BER_TLV_t **tlvs;
 169     } tlvs; /**< V_tlvs_selected==TRUE */
 170   } V;
 171
 172   /** Creates a new constructed TLV which contains one TLV (\a
 173     * p_tlv). Or, if the parameter is NULL, then an empty constructed
 174     * TLV is created. */
 175   static ASN_BER_TLV_t* construct(ASN_BER_TLV_t *p_tlv);
 176   /** Creates a new non-constructed TLV with the given V-part.
 177     * Tagclass and -number are set to UNIV-0. If \a p_Vstr is NULL
 178     * then allocates a \a p_Vlen size buffer for Vstr.
 179     * Takes over ownership of \a p_Vstr */
 180   static ASN_BER_TLV_t* construct(size_t p_Vlen, unsigned char *p_Vstr);
 181   /** Creates a new non-constructed TLV with empty T, L and V part. */
 182   static ASN_BER_TLV_t* construct();
 183   /** Frees the given \a p_tlv recursively. Tstr, Lstr and
 184     * Vstr/tlvs. If \a no_str is TRUE, then only the tlvs are deleted,
 185     * the strings (Tstr, Lstr, Vstr) are not. This is useful during
 186     * decoding, when the Xstr points into a buffer.*/
 187   static void destruct(ASN_BER_TLV_t *p_tlv, boolean no_str=FALSE);
 188   /** Checks the 'constructed' flag. If fails, raises an EncDec
 189     * error. */
 190   void chk_constructed_flag(boolean flag_expected) const;
 191   /** Adds \a p_tlv to this (constructed) TLV.
 192    * @pre isConstructed   is \c true
 193    * @pre V_tlvs_selected is \c true */
 194   void add_TLV(ASN_BER_TLV_t *p_tlv);
 195   /** Adds a new UNIVERSAL 0 TLV to this (constructed) TLV. */
 196   void add_UNIV0_TLV();
 197   /** Returns the length (in bytes) of the full TLV. */
 198   size_t get_len() const;
 199   /** Adds T and L part to TLV. It adds trailing UNI-0 TLV (two zero
 200     * octets) if the length form is indefinite. Precondition:
 201     * isConstructed (and V_tlvs_selected) and V-part are valid. */
 202   void add_TL(ASN_Tagclass_t p_tagclass,
 203               ASN_Tagnumber_t p_tagnumber,
 204               unsigned coding);
 205   /** Puts the TLV in buffer \a p_buf. */
 206   void put_in_buffer(TTCN_Buffer& p_buf);
 207   /** Gets the octet in position \a pos. Works also for constructed TLVs. */
 208   unsigned char get_pos(size_t pos) const;
 209 private:
 210   unsigned char _get_pos(size_t& pos, boolean& success) const;
 211 public:
 212   /** Compares the TLVs as described in X.690 11.6. Returns -1 if this
 213     * less than, 0 if equal to, 1 if greater than other. */
 214   int compare(const ASN_BER_TLV_t *other) const;
 215   /** Sorts its TLVs according to their octetstring representation, as
 216     * described in X.690 11.6. */
 217   void sort_tlvs();
 218   /** Compares the TLVs according their tags as described in X.680
 219     * 8.6. Returns -1 if this less than, 0 if equal to, 1 if greater
 220     * than other. */
 221   int compare_tags(const ASN_BER_TLV_t *other) const;
 222   /** Sorts its TLVs according to their tags, as described in X.690
 223     * 10.3. */
 224   void sort_tlvs_tag();
 225 };
 226
 227 /**
 228   * Searches the T, L and V parts of the TLV represented in \a s, and
 229   * stores it in \a tlv. Returns FALSE if there isn't a complete
 230   * TLV-structure in \a s, TRUE otherwise.
 231   */
 232 boolean ASN_BER_str2TLV(size_t p_len_s,
 233                         const unsigned char* p_str,
 234                         ASN_BER_TLV_t& tlv,
 235                         unsigned L_form);
 236
 237 /**
 238   * Adds the T and L part of the TLV. If there are multiple tags, then
 239   * adds them all. Precondition: the following fields are ready of \a
 240   * p_tlv: isConstructed, V_tlvs_selected, isLenDefinite, isLenShort
 241   * and V. If tagclass and tagnumber are UNIVERSAL 0, then replaces
 242   * them, otherwise 'wraps' p_tlv in a new TLV.
 243   */
 244 ASN_BER_TLV_t* ASN_BER_V2TLV(ASN_BER_TLV_t* p_tlv,
 245                              const TTCN_Typedescriptor_t& p_td,
 246                              unsigned coding);
 247
 248 /** @} end of BER group */
 249
 250 #endif // _BER_HH