asn1_read_value(3) libtasn1 asn1_read_value(3)
asn1_read_value - API function
int asn1_read_value(asn1_node root, const char * name, void * ivalue, int * len);
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.
int * len number of bytes of *value: value..value[len-1]. Initialy holds the sizeof
Returns the value of one element inside a structure.
If an element is OPTIONAL and the function "read_value" 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.
VALUE will contain a two's complement form integer.
integer=-1 -> value=0xFF , len=1. integer=1 -> value=0x01 , len=1.
As INTEGER (but only with not negative numbers).
VALUE will be the null terminated string "TRUE" or "FALSE" and LEN=5 or LEN=6.
VALUE will be a null terminated string with each number separated by a dot (i.e.
LEN = strlen(VALUE)+1
VALUE will be a null terminated string in one of these formats: "YYMMDDhhmmss+hh'mm'" or
VALUE will be a null terminated string in the same format used to set the value.
VALUE will contain the octet string and LEN will be the number of octets.
VALUE will contain the generalstring and LEN will be the number of octets.
VALUE will contain the bit string organized by bytes and LEN will be the number of bits.
If NAME indicates a choice type, VALUE will specify the alternative selected.
If NAME indicates an any type, VALUE will indicate the DER encoding of the structure actu-
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 con-
tain the number of bytes needed.
Copyright (C) 2006-2013 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.
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
should give you access to the complete manual.
libtasn1 3.3 asn1_read_value(3)