asn1_get_length_der(3)

📦
version 4.21.0 · 5 versions
, in alpine 3.22, alpine 3.23, alpine 3.24, arch rolling, fedora 43, fedora 44, opensuse-leap 16.0, ubuntu resolute, ubuntu stonking

💖 asn1_get_length_der(3) 💖

okay bestie, welcome to the libtasn1 corner of the man pages, where we decode DER length fields and feel iconic doing it ✨ this one's from the libtasn1 manual, section 3, and it's literally just vibes and byte math.

🎀 NAME 🎀

asn1_get_length_der — it's an API function, bestie. that's the whole job description 💅

✨ SYNOPSIS ✨

#include <libtasn1.h>

long asn1_get_length_der(const unsigned char * der, int der_len, int *
len);

yes the line break in the signature is exactly like that, we don't make the rules 🫶

🌸 ARGUMENTS 🌸

  • const unsigned char * der — the DER data you wanna decode. hand it over, she'll handle it 💖
  • int der_len — how long that DER data is. length of DER data to decode, fr fr.
  • int * len — an output variable, so she writes back into it: it'll hold the length of the DER length field. it's giving "here's your receipt" 🧾✨

🦋 DESCRIPTION 🦋

Extract a length field from DER data. that's it, that's the whole thing. she pulls the length field out of the DER data and hands it to you 🌈

👑 RETURNS 👑

so here's the tea on what comes back ☕:

  • the decoded length value, obviously, when everything's good 💚
  • -1 on indefinite length. not today, babes 🙈
  • -2 when the value was too big to fit in a int. she tried, she really did 😭
  • -4 when the decoded length value plus len would exceed der_len. nope, out of bounds, we don't do that here 💀
lowkey important: those negative numbers are the error girlies. if you see -1, -2, or -4, that's not a length, that's a "something went wrong" ✋

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. so like, share it, remix it, just keep the receipts 🫶✨

🌟 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/

and that's the whole page bestie, no cap 💅 this was libtasn1 version 4.21.0, page asn1_get_length_der(3), brought to you by the fine folks at the Free Software Foundation. go decode some lengths, you absolute main character 🦋💖⭐

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