asn1\_read\_tag(3) libtasn1 asn1\_read\_tag(3)

# [NAME](#NAME)

asn1\_read\_tag - API function

# [SYNOPSIS](#SYNOPSIS)

**#include <libtasn1.h>**

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

# [ARGUMENTS](#ARGUMENTS)

[asn1\_node\_const root](#asn1_node_const)

pointer to a structure

[const char * name](#const)

the name of the element inside a structure.

[int * tagValue](#int)

variable that will contain the TAG value.

[int * classValue](#int~2)

variable that will specify the TAG type.

# [DESCRIPTION](#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](#RETURNS)

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

# [COPYRIGHT](#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](#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/**

4.21.0 libtasn1

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Document: asn1_read_tag(3) from libtasn1 4.21.0-r6 (Chainguard OS)
Source: https://gitlab.com/gnutls/libtasn1