/ 
Alien-ngtcp2-0.03
/ Alien::ngtcp2

NAME

Alien::ngtcp2 - Find or build the native libraries needed for QUIC

SYNOPSIS

use Alien::ngtcp2;

my $cflags = Alien::ngtcp2->cflags;
my $libs   = Alien::ngtcp2->libs;

my $crypto_cflags = Alien::ngtcp2->crypto_cflags;
my $crypto_libs   = Alien::ngtcp2->crypto_libs;

DESCRIPTION

Alien::ngtcp2 supplies the native ngtcp2 libraries needed by Perl QUIC distributions.

QUIC needs two native pieces:

  • libngtcp2, which handles the QUIC protocol

  • a TLS helper, which connects ngtcp2 to TLS 1.3

Alien::ngtcp2 uses Picotls for the TLS helper. Picotls is small, designed for TLS 1.3, and works well with QUIC.

OpenSSL is used underneath Picotls for cryptography and X.509 certificate handling. OpenSSL is not used as the QUIC TLS implementation.

HOW INSTALLATION WORKS

Alien::ngtcp2 builds a tested pair:

ngtcp2 1.25.0
Picotls commit f07f1c8c68b237f1468bc1f1fe1b68aba3ff23b4

The pair is built together instead of reusing an arbitrary system libngtcp2_crypto_picotls. The system helper does not record which Picotls revision it was built against.

On Unix-like systems, a system OpenSSL 1.1.1 or newer is used when available. If no suitable OpenSSL development installation is available, Alien::OpenSSL can provide one.

Windows

On Windows, Alien::ngtcp2 uses the OpenSSL that belongs to the active Perl and compiler toolchain.

If that OpenSSL is older than 1.1.1, installation stops with a clear error. Alien::ngtcp2 does not silently install a second TLS stack on Windows.

Historical Strawberry Perl 5.28 contains OpenSSL 1.1.0j and is therefore too old. Strawberry Perl 5.30 and newer meet the required baseline.

METHODS

cflags

Returns compiler flags for the core libngtcp2 library.

libs

Returns linker flags for the core libngtcp2 library.

crypto_backend

Returns picotls.

This method remains available so downstream distributions written for Alien::ngtcp2 0.02 do not need an API change.

crypto_package

Returns libngtcp2_crypto_picotls.

crypto_cflags

Returns the compiler flags needed to use the ngtcp2 Picotls helper.

crypto_libs

Returns the linker flags needed to use the ngtcp2 Picotls helper.

VERSIONS

Alien::ngtcp2 requires Perl 5.20 or newer and Alien::Build 2.84 or newer.

The bundled ngtcp2 source is version 1.25.0.

BUNDLED PICOTLS SOURCE

Alien::ngtcp2 contains the MIT-licensed Picotls TLS core and OpenSSL binding from commit:

f07f1c8c68b237f1468bc1f1fe1b68aba3ff23b4

This is the Picotls revision documented by ngtcp2 1.25.0.

The Picotls minicrypto backend and its third-party dependencies are not included.

SEE ALSO

Alien::Base

Alien::OpenSSL

https://github.com/ngtcp2/ngtcp2

https://github.com/h2o/picotls

AUTHOR

Joshua S. Day

COPYRIGHT AND LICENSE

This software is Copyright (c) 2026 by Joshua S. Day.

This is free software, licensed under:

The MIT (X11) License