asn1\_get\_octet\_der(3) libtasn1 asn1\_get\_octet\_der(3)

# [NAME](#NAME)

asn1\_get\_octet\_der - API function

# [SYNOPSIS](#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](#ARGUMENTS)

[const unsigned char * der](#const)

DER data to decode containing the OCTET SEQUENCE.

[int der\_len](#int)

The length of the *der* data to decode.

[int * ret\_len](#int~2)

Output variable containing the encoded length of the DER data.

[unsigned char * str](#unsigned)

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

[int str\_size](#int~3)

Length of pre-allocated output buffer.

[int * str\_len](#int~4)

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

# [DESCRIPTION](#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)

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

# [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_get_octet_der(3) from libtasn1 4.21.0-r8 (Chainguard OS)
Source: https://gitlab.com/gnutls/libtasn1