common/tlv.h

   1 /* tlv.h - Tag-Length-Value Utilities
   2  *      Copyright (C) 2004 Free Software Foundation, Inc.
   3  *
   4  * This file is part of GnuPG.
   5  *
   6  * GnuPG is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GnuPG is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #ifndef SCD_TLV_H
  21 #define SCD_TLV_H 1
  22
  23
  24 enum tlv_tag_class {
  25   CLASS_UNIVERSAL = 0,
  26   CLASS_APPLICATION = 1,
  27   CLASS_CONTEXT = 2,
  28   CLASS_PRIVATE =3
  29 };
  30
  31 enum tlv_tag_type {
  32   TAG_NONE = 0,
  33   TAG_BOOLEAN = 1,
  34   TAG_INTEGER = 2,
  35   TAG_BIT_STRING = 3,
  36   TAG_OCTET_STRING = 4,
  37   TAG_NULL = 5,
  38   TAG_OBJECT_ID = 6,
  39   TAG_OBJECT_DESCRIPTOR = 7,
  40   TAG_EXTERNAL = 8,
  41   TAG_REAL = 9,
  42   TAG_ENUMERATED = 10,
  43   TAG_EMBEDDED_PDV = 11,
  44   TAG_UTF8_STRING = 12,
  45   TAG_REALTIVE_OID = 13,
  46   TAG_SEQUENCE = 16,
  47   TAG_SET = 17,
  48   TAG_NUMERIC_STRING = 18,
  49   TAG_PRINTABLE_STRING = 19,
  50   TAG_TELETEX_STRING = 20,
  51   TAG_VIDEOTEX_STRING = 21,
  52   TAG_IA5_STRING = 22,
  53   TAG_UTC_TIME = 23,
  54   TAG_GENERALIZED_TIME = 24,
  55   TAG_GRAPHIC_STRING = 25,
  56   TAG_VISIBLE_STRING = 26,
  57   TAG_GENERAL_STRING = 27,
  58   TAG_UNIVERSAL_STRING = 28,
  59   TAG_CHARACTER_STRING = 29,
  60   TAG_BMP_STRING = 30
  61 };
  62
  63
  64 /* Locate a TLV encoded data object in BUFFER of LENGTH and return a
  65    pointer to value as well as its length in NBYTES.  Return NULL if
  66    it was not found or if the object does not fit into the buffer. */
  67 const unsigned char *find_tlv (const unsigned char *buffer, size_t length,
  68                                int tag, size_t *nbytes);
  69
  70
  71 /* Locate a TLV encoded data object in BUFFER of LENGTH and return a
  72    pointer to value as well as its length in NBYTES.  Return NULL if
  73    it was not found.  Note, that the function does not check whether
  74    the value fits into the provided buffer.*/
  75 const unsigned char *find_tlv_unchecked (const unsigned char *buffer,
  76                                          size_t length,
  77                                          int tag, size_t *nbytes);
  78
  79
  80 /* ASN.1 BER parser: Parse BUFFER of length SIZE and return the tag
  81    and the length part from the TLV triplet.  Update BUFFER and SIZE
  82    on success. */
  83 gpg_error_t _parse_ber_header (unsigned char const **buffer, size_t *size,
  84                                int *r_class, int *r_tag,
  85                                int *r_constructed,
  86                                int *r_ndef, size_t *r_length, size_t *r_nhdr,
  87                                gpg_err_source_t errsource);
  88 #define parse_ber_header(a,b,c,d,e,f,g,h) \
  89         _parse_ber_header ((a),(b),(c),(d),(e),(f),(g),(h),\
  90                            GPG_ERR_SOURCE_DEFAULT)
  91
  92
  93 /* Return the next token of an canconical encoded S-expression.  BUF
  94    is the pointer to the S-expression and BUFLEN is a pointer to the
  95    length of this S-expression (used to validate the syntax).  Both
  96    are updated to reflect the new position.  The token itself is
  97    returned as a pointer into the orginal buffer at TOK and TOKLEN.
  98    If a parentheses is the next token, TOK will be set to NULL.
  99    TOKLEN is checked to be within the bounds.  On error a error code
 100    is returned and all pointers should are not guaranteed to point to
 101    a meanigful value. DEPTH should be initialized to 0 and will
 102    reflect on return the actual depth of the tree. To detect the end
 103    of the S-expression it is advisable to check DEPTH after a
 104    successful return. */
 105 gpg_error_t _parse_sexp (unsigned char const **buf, size_t *buflen,
 106                          int *depth, unsigned char const **tok, size_t *toklen,
 107                          gpg_err_source_t errsource);
 108 #define parse_sexp(a,b,c,d,e) \
 109         _parse_sexp ((a),(b),(c),(d),(e), GPG_ERR_SOURCE_DEFAULT)
 110
 111
 112
 113 #endif /* SCD_TLV_H */