---
name: "asn1_read_tag"
section: "3"
platform: "linux"
package: "libtasn1"
version: "4.21.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/asn1_read_tag"
---

# asn1\_read\_tag(3)

API function

## NAME

asn1\_read\_tag - API function

## SYNOPSIS

**#include \<libtasn1.h\>**

**int asn1\_read\_tag(asn1\_node\_const** *root***, const char \*** *name***, int \*** *tagValue***, int \*** *classValue***);**

## ARGUMENTS

- asn1\_node\_const root

  pointer to a structure

- const char \* name

  the name of the element inside a structure.

- int \* tagValue

  variable that will contain the TAG value.

- int \* classValue

  variable that will specify the TAG type.

## DESCRIPTION

Returns the TAG and the CLASS of one element inside a structure. CLASS can have one of these constants: **ASN1\_CLASS\_APPLICATION**, **ASN1\_CLASS\_UNIVERSAL**, **ASN1\_CLASS\_PRIVATE** or **ASN1\_CLASS\_CONTEXT\_SPECIFIC**.

## RETURNS

**ASN1\_SUCCESS** if successful, **ASN1\_ELEMENT\_NOT\_FOUND** if\
  *name* is not a valid element.

## COPYRIGHT

Copyright © 2006-2025 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:

-

  **https://www.gnu.org/software/libtasn1/manual/**