bionic (3) asn1_read_value.3.gz

Provided by: libtasn1-6-dev_4.13-2_amd64 bug

NAME
       asn1_read_value - API function


SYNOPSIS
       #include <libtasn1.h>

       int asn1_read_value(asn1_node root, const char * name, void * ivalue, int * len);


ARGUMENTS
       asn1_node root
                   pointer to a structure.

       const char * name
                   the name of the element inside a structure that you want to read.

       void * ivalue
                   vector  that  will  contain  the element's content, must be a pointer to memory cells already
                   allocated (may be NULL).

       int * len   number of bytes of *value: value[0]..value[len-1]. Initialy holds the sizeof value.


DESCRIPTION
       Returns the value of one element inside a  structure.   If  an  element  is  OPTIONAL  and  this  returns
       ASN1_ELEMENT_NOT_FOUND,  it  means  that this element wasn't present in the der encoding that created the
       structure.  The first element of a SEQUENCE_OF or SET_OF is named "?1". The second one "?2" and so on. If
       the  root provided is a node to specific sequence element, then the keyword "?CURRENT" is also acceptable
       and indicates the current sequence element of this node.

       Note that there can be valid values with length zero. In these case this function will succeed  and   len
       will be zero.


INTEGER
       VALUE will contain a two's complement form integer.

       integer=-1  -> value[0]=0xFF , len=1.  integer=1   -> value[0]=0x01 , len=1.


ENUMERATED
       As INTEGER (but only with not negative numbers).


BOOLEAN
       VALUE will be the null terminated string "TRUE" or "FALSE" and LEN=5 or LEN=6.

       OBJECT  IDENTIFIER:  VALUE  will  be  a  null terminated string with each number separated by a dot (i.e.
       "1.2.3.543.1").

       LEN = strlen(VALUE)+1


UTCTIME
       VALUE  will  be  a  null  terminated  string  in  one  of   these   formats:   "YYMMDDhhmmss+hh'mm'"   or
       "YYMMDDhhmmss-hh'mm'".  LEN=strlen(VALUE)+1.


GENERALIZEDTIME
       VALUE will be a null terminated string in the same format used to set the value.

       OCTET STRING: VALUE will contain the octet string and LEN will be the number of octets.


GENERALSTRING
       VALUE will contain the generalstring and LEN will be the number of octets.

       BIT STRING: VALUE will contain the bit string organized by bytes and LEN will be the number of bits.


CHOICE
       If NAME indicates a choice type, VALUE will specify the alternative selected.


ANY
       If NAME indicates an any type, VALUE will indicate the DER encoding of the structure actually used.


RETURNS
       ASN1_SUCCESS   if   value   is  returned,  ASN1_ELEMENT_NOT_FOUND  if   name  is  not  a  valid  element,
       ASN1_VALUE_NOT_FOUND if there isn't any value for the element selected, and ASN1_MEM_ERROR if  The  value
       vector  isn't  big  enough  to  store  the result, and in this case  len will contain the number of bytes
       needed.


       Copyright © 2006-2015 Free Software Foundation, Inc..
       Copying and distribution of this file, with or without modification, are permitted in any medium  without
       royalty provided the copyright notice and this notice are preserved.


SEE ALSO
       The full documentation for libtasn1 is maintained as a Texinfo manual.  If the info and libtasn1 programs
       are properly installed at your site, the command

              info libtasn1

       should give you access to the complete manual.  As an alternative you may obtain the manual from:

              http://www.gnu.org/software/libtasn1/manual/