[ новости /+++ | форум | теги | ]

NAME
     ber_encode,     ber_alloc,     ber_printf,      ber_put_int,
     ber_put_ostring,        ber_put_string,        ber_put_null,
     ber_put_boolean,      ber_put_bitstring,      ber_start_seq,
     ber_start_set,  ber_put_seq,  ber_put_set - simplified Basic
     Encoding Rules library encoding functions

SYNOPSIS
     cc[ flag... ] file... -lldap[ library... ]

     #include <lber.h>

     BerElement*ber_alloc();

     ber_printf(BerElement *ber, char **fmt[, arg... ]);

     ber_put_int(BerElement *ber, long num, char tag);

     ber_put_ostring(BerElement *ber, char **str,  unsigned  long
     len, char tag);

     ber_put_string(BerElement *ber, char **str, char tag);

     ber_put_null(BerElement *ber, char tag);

     ber_put_boolean(BerElement *ber, int bool, char tag);

     ber_put_bitstring(BerElement *ber, char *str, int blen, char
     tag);

     ber_start_seq(BerElement *ber, char tag);

     ber_start_set(BerElement *ber, char tag);

     ber_put_seq(BerElement *ber);

     ber_put_set(BerElement *ber);

DESCRIPTION
     These functions provide a subfunction interface to a simpli-
     fied  implementation  of  the Basic Encoding Rules of ASN.1.
     The version of  BER  these  functions  support  is  the  one
     defined  for  the LDAP protocol.  The encoding rules are the
     same as BER, except that  only  definite  form  lengths  are
     used, and bitstrings and octet strings are always encoded in
     primitive form.  In addition, these  lightweight  BER  func-
     tions restrict tags and class to fit in a single octet (this
     means the actual tag must be less than 31).  When a "tag" is
     specified  in  the descriptions below, it refers to the tag,
     class, and primitive or constructed bit in the  first  octet
     of the encoding.  This man page describes the encoding func-
     tions  in  the  lber  library.   See  ber_decode(3LDAP)  for
     details on the corresponding decoding functions.

     Normally, the only functions  that  need  be  called  by  an
     application are  ber_alloc(), to allocate a BER element, and
     ber_printf() to do the actual encoding.
      The other functions are  provided  for  those  applications
     that need more control than  ber_printf() provides.  In gen-
     eral, these functions  return  the  length  of  the  element
     encoded, or -1 if an error occurred.

     The  ber_alloc() function is used to allocate a new BER ele-
     ment.

     The  ber_printf() function is used to encode a  BER  element
     in much the same way that  sprintf(3S) works.
      One important difference, though, is that some state infor-
     mation is kept with the ber parameter so that multiple calls
     can be made to  ber_printf() to append things to the end  of
     the  BER element.   Ber_printf() writes to ber, a pointer to
     a BerElement such as returned by  ber_alloc(). It interprets
     and  formats  its  arguments  according to the format string
     fmt. The format string can contain the following characters:

     -b    Boolean.  An integer parameter should be supplied.   A
           boolean element is output.

     -i    Integer. An integer parameter should be supplied.   An
           integer element is output.

     -B    Bitstring.
            A char * pointer to the start  of  the  bitstring  is
           supplied,  followed  by the number of bits in the bit-
           string.  A bitstring element is output.

     -n    Null.  No parameter is required.  A  null  element  is
           output.

     -o    Octet string.
            A char * is supplied, followed by the length  of  the
           string pointed to.
            An octet string element is output.

     -s    Octet string.
            A  null-terminated  string  is  supplied.   An  octet
           string  element  is output, not including the trailing
           NULL octet.

     -t    Tag.  An int specifying the tag to give the next  ele-
           ment is provided. This works across calls.

     -v    Several octet strings.   A  null-terminated  array  of
           char  *'s  is  supplied.   Note  that a construct like
           '{v}' is required to get an actual SEQUENCE  OF  octet
           strings.

     -{    Begin sequence.  No parameter is required.

     -}    End sequence.  No parameter is required.

     -[    Begin set.  No parameter is required.

     -]    End set.  No parameter is required.

     The  ber_put_int() function writes the integer  element  num
     to the BER element ber.

     The  ber_put_boolean() function  writes  the  boolean  value
     given by bool to the BER element.

     The  ber_put_bitstring() function writes blen bits  starting
     at  str as a bitstring value to the given BER element.  Note
     that blen is the length in bits of the bitstring.

     The  ber_put_ostring() function writes len bytes starting at
     str to the BER element as an octet string.

     The  ber_put_string() function  writes  the  null-terminated
     string  (minus  the terminating '') to the BER element as an
     octet string.

     The  ber_put_null() function writes a  NULL element  to  the
     BER element.

     The  ber_start_seq() function is used to start a sequence in
     the  BER element.  The  ber_start_set() function works simi-
     larly. The end of the sequence  or  set  is  marked  by  the
     nearest  matching  call to  ber_put_seq() or  ber_put_set(),
     respectively.

     The  ber_first_element() function is used to return the  tag
     and  length  of  the first element in a set or sequence.  It
     also returns in cookie a magic cookie parameter that  should
     be  passed  to subsequent calls to ber_next_element(), which
     returns similar information.

EXAMPLES
     Example 1: Assuming the following variable declarations, and
     that  the variables have been assigned appropriately, an BER
     encoding of the following ASN.1 object:

           AlmostASearchRequest := SEQUENCE {
               baseObject      DistinguishedName,
               scope           ENUMERATED {
                   baseObject    (0),
                   singleLevel   (1),
                   wholeSubtree  (2)
               },
               derefAliases    ENUMERATED {
                   neverDerefaliases   (0),
                   derefInSearching    (1),
                   derefFindingBaseObj (2),
                   alwaysDerefAliases  (3N)
               },
               sizelimit       INTEGER (0 .. 65535),
               timelimit       INTEGER (0 .. 65535),
               attrsOnly       BOOLEAN,
               attributes      SEQUENCE OF AttributeType
           }

     can be achieved like so:

           int    scope, ali, size, time, attrsonly;
           char   *dn, **attrs;

           /* ... fill in values ... */
           if ( (ber = ber_alloc()) == NULLBER )
           /* error */

           if ( ber_printf( ber, "{siiiib{v}}", dn, scope, ali,
               size, time, attrsonly, attrs ) == -1 )
                   /* error */
           else
                   /* success */

RETURN VALUES
     If an error  occurs  during  encoding,  ber_alloc()  returns
     NULL; other functions generally return -1.

ATTRIBUTES
     See attributes(5) for a description of the following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWlldap (32-bit)          |
    |_____________________________|_____________________________|
    |                             | SUNWldapx (64-bit)          |
    |_____________________________|_____________________________|
    | Stability Level             | Evolving                    |
    |_____________________________|_____________________________|


SEE ALSO
     attributes(5), ber_decode(3LDAP)

     Yeong, W., Howes, T., and Hardcastle-Kille, S., "Lightweight
     Directory Access Protocol", OSI-DS-26, April 1992.

     Information Processing  -  Open  Systems  Interconnection  -
     Model  and  Notation - Service Definition - Specification of
     Basic Encoding  Rules  for  Abstract  Syntax  Notation  One,
     International  Organization  for  Standardization,  Interna-
     tional Standard 8825.

NOTES
     The return values for all of these functions are declared in
     the <lber.h> header file.

Партнёры:

Хостинг: