---
name: "asn1_get_octet_der"
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_get_octet_der"
---

# asn1\_get\_octet\_der(3)

API function

## NAME

asn1\_get\_octet\_der - API function

## SYNOPSIS

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

**int asn1\_get\_octet\_der(const unsigned char \*** *der***, int** *der\_len***, int \*** *ret\_len***, unsigned char \*** *str***, int** *str\_size***, int \*** *str\_len***);**

## ARGUMENTS

- const unsigned char \* der

  DER data to decode containing the OCTET SEQUENCE.

- int der\_len

  The length of the  *der* data to decode.

- int \* ret\_len

  Output variable containing the encoded length of the DER data.

- unsigned char \* str

  Pre-allocated output buffer to put decoded OCTET SEQUENCE in.

- int str\_size

  Length of pre-allocated output buffer.

- int \* str\_len

  Output variable containing the length of the contents of the OCTET SEQUENCE.

## DESCRIPTION

Extract an OCTET SEQUENCE from DER data. Note that this function expects the DER data past the tag field, i.e., the length and content octets.

## RETURNS

Returns **ASN1\_SUCCESS** on success, or an error.

## 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/**