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

# [NAME](#NAME)

asn1\_octet\_der - API function

# [SYNOPSIS](#SYNOPSIS)

**#include <libtasn1.h>**

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

# [ARGUMENTS](#ARGUMENTS)

[const unsigned char * str](#const)

the input data.

[int str\_len](#int)

STR length (str\[0]..str\[\*str\_len-1]).

[unsigned char * der](#unsigned)

encoded string returned.

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

number of meaningful bytes of DER (der\[0]..der\[der\_len-1]).

# [DESCRIPTION](#DESCRIPTION)

Creates a length-value DER encoding for the input data. The DER encoding of the input data will be placed in the *der* variable.

Note that the OCTET STRING tag is not included in the output.

This function does not return any value because it is expected that *der\_len* will contain enough bytes to store the string plus the DER encoding. The DER encoding size can be obtained using **asn1\_length\_der()**.

# [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_octet_der(3) from libtasn1 4.21.0-r6 (Chainguard OS)
Source: https://gitlab.com/gnutls/libtasn1