Crypt::SSLeay(3) OpenSSL support for LWP


"perl Makefile.PL" will display a warning if it thinks your OpenSSL might be vulnerable to the Heartbleed Bug <>. You can, of course, go ahead and install the module, but you should be aware that your system might be exposed to an extremely serious vulnerability. This is just a heuristic based on the version reported by OpenSSL. It is entirely possible that your distrbution actually pushed a patched library, so if you have concerns, you should investigate further.


use Net::SSL;
use LWP::UserAgent;
my $ua = LWP::UserAgent->new(
ssl_opts => { verify_hostname => 0 },
my $response = $ua->get('');
print $response->content, "\n";


This Perl module provides support for the HTTPS protocol under LWP, to allow an LWP::UserAgent object to perform GET, HEAD, and POST requests over encrypted socket connections. Please see LWP for more information on POST requests.

The "Crypt::SSLeay" package provides "Net::SSL", which, if requested, is loaded by "LWP::Protocol::https" for https requests and provides the necessary SSL glue.

This distribution also makes following deprecated modules available:


DO YOU NEED Crypt::SSLeay?

Starting with version 6.02 of LWP, "https" support was unbundled into LWP::Protocol::https. This module specifies as one of its prerequisites IO::Socket::SSL which is automatically used by LWP::UserAgent unless this preference is overridden separately. "IO::Socket::SSL" is a more complete implementation, and, crucially, it allows hostname verification. "Crypt::SSLeay" does not support this. At this point, "Crypt::SSLeay" is maintained to support existing software that already depends on it. However, it is possible that your software does not really depend on "Crypt::SSLeay", only on the ability of "LWP::UserAgent" class to communicate with sites over SSL/TLS.

If are using version "LWP" 6.02 or later, and therefore have installed "LWP::Protocol::https" and its dependencies, and do not explicitly "use" "Net::SSL" before loading "LWP::UserAgent", or override the default socket class, you are probably using "IO::Socket::SSL" and do not really need "Crypt::SSLeay".

If you have both "Crypt::SSLeay" and "IO::Socket::SSL" installed, and would like to force "LWP::UserAgent" to use "Crypt::SSLeay", you can use:

    use Net::HTTPS;
    use LWP::UserAgent;


    use LWP::UserAgent;


    use Net::SSL;
    use LWP::UserAgent;


Specify SSL Socket Class
$ENV{PERL_NET_HTTPS_SSL_SOCKET_CLASS} can be used to instruct "LWP::UserAgent" to use "Net::SSL" for HTTPS support rather than "IO::Socket::SSL".
Proxy Support
    $ENV{HTTPS_PROXY} = 'http://proxy_hostname_or_ip:port';

Proxy Basic Authentication
    $ENV{HTTPS_PROXY_USERNAME} = 'username';
    $ENV{HTTPS_PROXY_PASSWORD} = 'password';
SSL diagnostics and Debugging
    $ENV{HTTPS_DEBUG} = 1;
Default SSL Version
    $ENV{HTTPS_VERSION} = '3';
Client Certificate Support
    $ENV{HTTPS_CERT_FILE} = 'certs/notacacert.pem';
    $ENV{HTTPS_KEY_FILE}  = 'certs/notacakeynopass.pem';
CA cert Peer Verification
    $ENV{HTTPS_CA_FILE}   = 'certs/ca-bundle.crt';
    $ENV{HTTPS_CA_DIR}    = 'certs/';
Client PKCS12 cert support
    $ENV{HTTPS_PKCS12_FILE}     = 'certs/pkcs12.pkcs12';



You must have OpenSSL installed before compiling this module. You can get the latest OpenSSL package from <>. We no longer support pre-2000 versions of OpenSSL.

If you are building OpenSSL from source, please follow the directions included in the source package.

Crypt::SSLeay via Makefile.PL

"Makefile.PL" accepts the following command line arguments:
Path to OpenSSL headers. Can also be specified via $ENV{OPENSSL_INCLUDE}. If the command line argument is provided, it overrides any value specified via the environment variable. Of course, you can ignore both the command line argument and the environment variable, and just add the path to your compiler specific environment variable such as "CPATH" or "INCLUDE" etc.
Path to OpenSSL libraries. Can also be specified via $ENV{OPENSSL_LIB}. If the command line argument is provided, it overrides any value specified by the environment variable. Of course, you can ignore both the command line argument and the environment variable and just add the path to your compiler specific environment variable such as "LIBRARY_PATH" or "LIB" etc.
Use "--live-tests" to request tests that try to connect to an external web site, and "--no-live_tests" to prevent such tests from running. If you run "Makefile.PL" interactively, and this argument is not specified on the command line, you will be prompted for a value.

Default is false.

Boolean. Default is false. TODO: Does it work?
Boolean. Default is false. If you pass "--verbose" on the command line, both "Devel::CheckLib" and "ExtUtils::CBuilder" instances will be configured to echo what they are doing.

If everything builds OK, but you get failures when during tests, ensure that "LD_LIBRARY_PATH" points to the location where the correct shared libraries are located.

If you are using a custom OpenSSL build, please keep in mind that "Crypt::SSLeay" must be built using the same compiler and build tools used to build "perl" and OpenSSL. This can be more of an issue on Windows. If you are using Active State Perl, install the MinGW package distributed by them, and build OpenSSL using that before trying to build this module. If you have built your own Perl using Microsoft SDK tools or IDEs, make sure you build OpenSSL using the same tools.

Depending on your OS, pre-built OpenSSL packages may be available. To get the require headers and import libraries, you may need to install a development version of your operating system's OpenSSL library package. The key is that "Crypt::SSLeay" makes calls to the OpenSSL library, and how to do so is specified in the C header files that come with the library. Some systems break out the header files into a separate package from that of the libraries. Once the program has been built, you don't need the headers any more.


The latest Crypt::SSLeay can be found at your nearest CPAN mirror, as well as <>.

Once you have downloaded it, "Crypt::SSLeay" installs easily using the standard build process:

    $ perl Makefile.PL
    $ make
    $ make test
    $ make install


    $ cpanm Crypt::SSLeay

If you have OpenSSL headers and libraries in nonstandard locations, you can use

    $ perl Makefile.PL --incpath=... --libpath=...

If you would like to use "cpanm" with such custom locations, you can do

    $ OPENSSL_INCLUDE=... OPENSSL_LIB=... cpanm Crypt::SSLeay

or, on Windows,

    > set OPENSSL_INCLUDE=...
    > set OPENSSL_LIB=...
    > cpanm Crypt::SSLeay

If you are on Windows, and using a MinGW distribution bundled with ActiveState Perl or Strawberry Perl, you would use "dmake" rather than "make". If you are using Microsoft's build tools, you would use "nmake".

For unattended (batch) installations, to be absolutely certain that Makefile.PL does not prompt for questions on STDIN, set the environment variable "PERL_MM_USE_DEFAULT=1" as with any CPAN module built using ExtUtils::MakeMaker.


I do not have any experience with VMS. If OpenSSL headers and libraries are not in standard locations searched by your build system by default, please set things up so that they are. If you have generic instructions on how to do it, please open a ticket on RT with the information so I can add it to this document.


LWP::UserAgent and Crypt::SSLeay have their own versions of proxy support. Please read these sections to see which one is appropriate.

LWP::UserAgent proxy support

"LWP::UserAgent" has its own methods of proxying which may work for you and is likely to be incompatible with "Crypt::SSLeay" proxy support. To use "LWP::UserAgent" proxy support, try something like:

    my $ua = LWP::UserAgent->new;
    $ua->proxy([qw( https http )], "$proxy_ip:$proxy_port");

At the time of this writing, libwww v5.6 seems to proxy https requests fine with an Apache mod_proxy server. It sends a line like:

    GET HTTP/1.1

to the proxy server, which is not the "CONNECT" request that some proxies would expect, so this may not work with other proxy servers than mod_proxy. The "CONNECT" method is used by "Crypt::SSLeay"'s internal proxy support.

Crypt::SSLeay proxy support

For native "Crypt::SSLeay" proxy support of https requests, you need to set the environment variable "HTTPS_PROXY" to your proxy server and port, as in:

    # proxy support
    $ENV{HTTPS_PROXY} = 'http://proxy_hostname_or_ip:port';
    $ENV{HTTPS_PROXY} = '';

Use of the "HTTPS_PROXY" environment variable in this way is similar to "LWP::UserAgent-"env_proxy()> usage, but calling that method will likely override or break the "Crypt::SSLeay" support, so do not mix the two.

Basic auth credentials to the proxy server can be provided this way:

    # proxy_basic_auth
    $ENV{HTTPS_PROXY_USERNAME} = 'username';
    $ENV{HTTPS_PROXY_PASSWORD} = 'password';

For an example of LWP scripting with "Crypt::SSLeay" native proxy support, please look at the eg/lwp-ssl-test script in the "Crypt::SSLeay" distribution.


Client certificates are supported. PEM encoded certificate and private key files may be used like this:

    $ENV{HTTPS_CERT_FILE} = 'certs/notacacert.pem';
    $ENV{HTTPS_KEY_FILE}  = 'certs/notacakeynopass.pem';

You may test your files with the eg/net-ssl-test program, bundled with the distribution, by issuing a command like:

    perl eg/net-ssl-test -cert=certs/notacacert.pem \
        -key=certs/notacakeynopass.pem -d GET $HOST_NAME

Additionally, if you would like to tell the client where the CA file is, you may set these.

    $ENV{HTTPS_CA_FILE} = "some_file";
    $ENV{HTTPS_CA_DIR}  = "some_dir";

Note that, if specified, $ENV{HTTPS_CA_FILE} must point to the actual certificate file. That is, $ENV{HTTPS_CA_DIR} is *not* the path were $ENV{HTTPS_CA_FILE} is located.

For certificates in $ENV{HTTPS_CA_DIR} to be picked up, follow the instructions on <>

There is no sample CA cert file at this time for testing, but you may configure eg/net-ssl-test to use your CA cert with the -CAfile option.

(TODO: then what is the ./certs directory in the distribution?)

Creating a test certificate

To create simple test certificates with OpenSSL, you may run the following command:

    openssl req -config /usr/local/openssl/openssl.cnf \
        -new -days 365 -newkey rsa:1024 -x509 \
        -keyout notacakey.pem -out notacacert.pem

To remove the pass phrase from the key file, run:

    openssl rsa -in notacakey.pem -out notacakeynopass.pem

PKCS12 support

The directives for enabling use of PKCS12 certificates is:

    $ENV{HTTPS_PKCS12_FILE}     = 'certs/pkcs12.pkcs12';

Use of this type of certificate takes precedence over previous certificate settings described.

(TODO: unclear? Meaning ``the presence of this type of certificate''?)

SSL versions

"Crypt::SSLeay" tries very hard to connect to any SSL web server accommodating servers that are buggy, old or simply not standards-compliant. To this effect, this module will try SSL connections in this order:
SSL v23
should allow v2 and v3 servers to pick their best type
SSL v3
best connection type
SSL v2
old connection type

Unfortunately, some servers seem not to handle a reconnect to SSL v3 after a failed connect of SSL v23 is tried, so you may set before using LWP or Net::SSL:


to force a version 3 SSL connection first. At this time only a version 2 SSL connection will be tried after this, as the connection attempt order remains unchanged by this setting.


Many thanks to the following individuals who helped improve "Crypt-SSLeay":

Gisle Aas for writing this module and many others including libwww, for perl. The web will never be the same :)

Ben Laurie deserves kudos for his excellent patches for better error handling, SSL information inspection, and random seeding.

Dongqiang Bai for host name resolution fix when using a proxy.

Stuart Horner of Core Communications, Inc. who found the need for building "--shared" OpenSSL libraries.

Pavel Hlavnicka for a patch for freeing memory when using a pkcs12 file, and for inspiring more robust "read()" behavior.

James Woodyatt is a champ for finding a ridiculous memory leak that has been the bane of many a Crypt::SSLeay user.

Bryan Hart for his patch adding proxy support, and thanks to Tobias Manthey for submitting another approach.

Alex Rhomberg for Alpha linux ccc patch.

Tobias Manthey for his patches for client certificate support.

Daisuke Kuroda for adding PKCS12 certificate support.

Gamid Isayev for CA cert support and insights into error messaging.

Jeff Long for working through a tricky CA cert SSLClientVerify issue.

Chip Turner for a patch to build under perl 5.8.0.

Joshua Chamas for the time he spent maintaining the module.

Jeff Lavallee for help with alarms on read failures (CPAN bug #12444).

Guenter Knauf for significant improvements in configuring things in Win32 and Netware lands and Jan Dubois for various suggestions for improvements.

and many others who provided bug reports, suggestions, fixes and patches.

If you have reported a bug or provided feedback, and you would like to be mentioned by name in this section, please file request on <>.


For issues related to using of "Crypt::SSLeay" & "Net::SSL" with Perl's LWP, please send email to "[email protected]".

For OpenSSL or general SSL support, including issues associated with building and installing OpenSSL on your system, please email the OpenSSL users mailing list at "[email protected]". See <> for other mailing lists and archives.

Please report all bugs using <>.


This module was originally written by Gisle Aas, and was subsequently maintained by Joshua Chamas, David Landgren, brian d foy and Sinan Unur.


Copyright (c) 2010-2014 A. Sinan Unur

Copyright (c) 2006-2007 David Landgren

Copyright (c) 1999-2003 Joshua Chamas

Copyright (c) 1998 Gisle Aas


This program is free software; you can redistribute it and/or modify it under the terms of Artistic License 2.0 (see <>).