shishi_asn1_read_optional(3)					      shishi					      shishi_asn1_read_optional(3)

NAME

       shishi_asn1_read_optional - API function

SYNOPSIS

       #include <shishi.h>

       int shishi_asn1_read_optional(Shishi * handle, Shishi_asn1 node, const char * field, char ** data, size_t * datalen);

ARGUMENTS

       Shishi * handle
		   shishi handle as allocated by shishi_init().

       Shishi_asn1 node
		   ASN.1 variable to read field from.

       const char * field
		   name of field in node to read.

       char ** data
		   newly allocated output buffer that will hold ASN.1 field data.

       size_t * datalen
		   actual size of output buffer.

DESCRIPTION

       Extract data stored in a ASN.1 field into a newly allocated buffer.  If the field does not exist (i.e., SHISHI_ASN1_NO_ELEMENT), this func-
       tion set datalen to 0 and succeeds.  Can be useful to read ASN.1 fields which are marked OPTIONAL in the grammar, if you want to avoid spe-
       cial error handling in your code.

RETURN VALUE

       Returns SHISHI_OK if successful, SHISHI_ASN1_NO_VALUE if the field has no value, ot SHISHI_ASN1_ERROR otherwise.

REPORTING BUGS

       Report bugs to <bug-shishi@gnu.org>.

COPYRIGHT

       Copyright (C) 2002-2010 Simon Josefsson.
       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 shishi is maintained as a Texinfo manual.  If the info and shishi programs are properly installed at your  site,
       the command

	      info shishi

       should give you access to the complete manual.

shishi								       1.0.1					      shishi_asn1_read_optional(3)