asn1/ber_tlv_tag.h

   1 /*-
   2  * Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved.
   3  * Redistribution and modifications are permitted subject to BSD license.
   4  */
   5 #ifndef _BER_TLV_TAG_H_
   6 #define _BER_TLV_TAG_H_
   7
   8 #ifdef __cplusplus
   9 extern "C" {
  10 #endif
  11
  12 enum asn_tag_class {
  13         ASN_TAG_CLASS_UNIVERSAL         = 0,    /* 0b00 */
  14         ASN_TAG_CLASS_APPLICATION       = 1,    /* 0b01 */
  15         ASN_TAG_CLASS_CONTEXT           = 2,    /* 0b10 */
  16         ASN_TAG_CLASS_PRIVATE           = 3     /* 0b11 */
  17 };
  18 typedef unsigned ber_tlv_tag_t; /* BER TAG from Tag-Length-Value */
  19
  20 /*
  21  * Tag class is encoded together with tag value for optimization purposes.
  22  */
  23 #define BER_TAG_CLASS(tag)      ((tag) & 0x3)
  24 #define BER_TAG_VALUE(tag)      ((tag) >> 2)
  25 #define BER_TLV_CONSTRUCTED(tagptr)     (((*(const uint8_t *)tagptr)&0x20)?1:0)
  26
  27 #define BER_TAGS_EQUAL(tag1, tag2)      ((tag1) == (tag2))
  28
  29 /*
  30  * Several functions for printing the TAG in the canonical form
  31  * (i.e. "[PRIVATE 0]").
  32  * Return values correspond to their libc counterparts (if any).
  33  */
  34 ssize_t ber_tlv_tag_snprint(ber_tlv_tag_t tag, char *buf, size_t buflen);
  35 ssize_t ber_tlv_tag_fwrite(ber_tlv_tag_t tag, FILE *);
  36 char *ber_tlv_tag_string(ber_tlv_tag_t tag);
  37
  38
  39 /*
  40  * This function tries to fetch the tag from the input stream.
  41  * RETURN VALUES:
  42  *       0:     More data expected than bufptr contains.
  43  *      -1:     Fatal error deciphering tag.
  44  *      >0:     Number of bytes used from bufptr. tag_r will contain the tag.
  45  */
  46 ssize_t ber_fetch_tag(const void *bufptr, size_t size, ber_tlv_tag_t *tag_r);
  47
  48 /*
  49  * This function serializes the tag (T from TLV) in BER format.
  50  * It always returns number of bytes necessary to represent the tag,
  51  * it is a caller's responsibility to check the return value
  52  * against the supplied buffer's size.
  53  */
  54 size_t ber_tlv_tag_serialize(ber_tlv_tag_t tag, void *bufptr, size_t size);
  55
  56 #ifdef __cplusplus
  57 }
  58 #endif
  59
  60 #endif  /* _BER_TLV_TAG_H_ */