OpenSSL: Ubuntu

sumber: https://help.ubuntu.com/community/OpenSSL

Tentang OpenSSL

Secure Sockets Layer adalah protokol tingkat aplikasi yang dikembangkan oleh Netscape Corporation untuk tujuan mentransmisikan informasi sensitif, seperti detail Kartu Kredit, melalui Internet. SSL bekerja dengan menggunakan kunci pribadi untuk mengenkripsi data yang ditransfer melalui koneksi SSL-enabled, sehingga menggagalkan penyadapan informasi. Penggunaan SSL yang paling populer adalah bersamaan dengan penjelajahan web (menggunakan protokol HTTP), namun banyak aplikasi jaringan dapat memanfaatkan penggunaan SSL. Dengan konvensi, URL yang memerlukan sambungan SSL dimulai dengan https: bukan http :.

OpenSSL adalah penerapan alat SSL yang tangguh dan komersial, dan perpustakaan tujuan umum yang terkait berdasarkan SSLeay, dikembangkan oleh Eric A. Young dan Tim J. Hudson. OpenSSL tersedia sebagai Open Source setara dengan implementasi komersial SSL melalui lisensi bergaya Apache.

Tentang X.509

X.509 adalah spesifikasi untuk sertifikat digital yang diterbitkan oleh International Telecommunications Union - Telecommunication (ITU-T). Ini menentukan informasi dan atribut yang diperlukan untuk identifikasi seseorang atau sistem komputer, dan digunakan untuk pengelolaan yang aman dan distribusi sertifikat yang ditandatangani secara digital melalui jaringan Internet yang aman. OpenSSL paling sering menggunakan sertifikat X.509.

Penggunaan Praktis OpenSSL

Install OpenSSL Toolkit

Bisa menggunakan perintah

apt install openssl

Biasanya sudah terinstall di distribusi Ubuntu

Install OpenSSL Library

Cek libssl yang ada,

apt-cache search libssl | grep SSL
apt-cache search libssl

Keluar kira-kira

libssl-dev - Secure Sockets Layer toolkit - development files
libssl-doc - Secure Sockets Layer toolkit - development documentation
libssl1.0.0 - Secure Sockets Layer toolkit - shared libraries
libssl1.0.0-dbg - Secure Sockets Layer toolkit - debug information
cl-plus-ssl - Common Lisp interface to OpenSSL
libssl-ocaml - OCaml bindings for OpenSSL (runtime)
libssl-ocaml-dev - OCaml bindings for OpenSSL
libsslcommon2 - enterprise messaging system - common SSL libraries
libsslcommon2-dev - enterprise messaging system - common SSL development files

Install misalnya,

locale-gen id_ID.UTF-8
apt install libsslcommon2 libsslcommon2-dev libssl-dev libssl1.0.0 libssl1.0.0-dbg

Juga install ca-certificate

apt install ca-certificates

Jika di perlukan untuk java & mono, bisa di install juga

apt install ca-certificates-java
apt install ca-certificates-mono

Install OpenSSL Development Library

Jika dibutuhkan untuk membuat OpenSSL library, kita perlu menginstalasi

apt install libssl-dev

Basic OpenSSL Command

Bagian ini akan membahas perintah OpenSSL dasar. Untuk mengetahui OpenSSL versi yang di instalasi,

openssl version

Untuk melihat sub-command OpenSSL:

openssl help

Untuk mengetahui perintah sub-command, dapat digunakan (misalnya untuk perintah enc),

openssl -h enc

Untuk melihat semua algoritma cipher yang ada:

openssl ciphers -v

Untuk melakukan benchmark kecepatan komputer dengan OpenSSL,

openssl speed

SSL Certificate

Bagian berikut dari panduan ini akan memperkenalkan konsep yang terlibat dalam pembuatan dan penggunaan sertifikat SSL, baik varietas yang ditandatangani sendiri, dan yang ditandatangani oleh otoritas sertifikat yang diakui untuk digunakan dengan aplikasi server yang mendukung SSL, dan penggunaan X. 509 sertifikat dalam aplikasi klien

SSL Certificate untuk menggunaan Server

Setelah anda telah menghasilkan sertifikat SSL yang sesuai dengan X.509, anda dapat memilih untuk menandatangani sertifikat sendiri, dengan membuat Otoritas Sertifikat (Certificate Authority / CA), atau anda dapat memilih untuk memiliki Otoritas Sertifikat yang diakui secara global untuk menandatangani sertifikat. Saat sertifikat ditandatangani, maka sertifikat siap digunakan dengan toolkit OpenSSL, atau library untuk mengaktifkan koneksi SSL terenkripsi ke server, misalnya, Lightweight Directory Access Protoco (LDAP) atau Hyper Text Transport Protocol (HTTP). Bagian panduan ini menjelaskan tentang generasi sertifikat, dan proses penandatanganan untuk sertifikat tanda tangan yang ditandatangani sendiri, dan sertifikat CA yang telah ditandatangani.

Generating dan Signing Self-Signed Certificate

Self-signed Sertifikat memiliki keuntungan besar karena mereka benar-benar bebas untuk menggunakannya, dan dapat dihasilkan, ditandatangani, dan digunakan sesuai kebutuhan. Sertifikat self-signed sangat bagus untuk digunakan di lingkungan laboratorium tertutup atau untuk tujuan pengujian. Salah satu kelemahan menggunakan sertifikat yang ditandatangani sendiri, bagaimanapun, adalah bahwa peringatan biasanya akan dikeluarkan oleh browser Web pengguna, dan aplikasi lainnya, setelah mengakses server SSL-secure yang menggunakan sertifikat yang ditandatangani sendiri. Secara default, aplikasi klien (mis., Firefox) akan menekan peringatan tersebut untuk sertifikat yang ditandatangani hanya dengan menggunakan Otoritas Sertifikat yang diakui secara global dan terpercaya, namun peringatan juga dapat dimatikan dengan mengimpor sertifikat akar server ke aplikasi klien; Demonstrasi yang relevan ditunjukkan nanti dalam panduan ini. Menggunakan sertifikat yang ditandatangani sendiri di lingkungan produksi yang dapat diakses oleh publik tidak disarankan karena adanya masalah kepercayaan implisit yang timbul dari peringatan ini, selain potensi kebingungan pada pengguna.

CATATAN: Anda harus mendapatkan sertifikat yang ditandatangani oleh Otoritas Sertifikat yang diakui untuk membuat situs komersial, mis., Untuk melakukan "e-commerce".

Jika anda telah menginstal toolkit OpenSSL sebelumnya, atau sesuai petunjuk di atas, generasi sertifikat SSL X.509 cukup sederhana. Untuk sertifikat yang ditandatangani sendiri, anda harus terlebih dahulu membuat Otoritas Sertifikat (Certificate Authority / CA) dengan mengikuti langkah-langkah di bawah ini:

Membuat Certificate Authority

Pertama, buat lingkungan kerja awal, misalnya di dalam direktori home anda dengan mengeluarkan perintah berikut dari prompt terminal:

cd
mkdir -p myCA/signedcerts
mkdir myCA/private
cd myCA

Fungsi dari masing-masing directory adalah sebagai berikut,

~/myCA : berisi CA certificate, certificate database, generated certificate, key, dan request
~/myCA/signedcerts : berisi copy dari setiap signed certificate
~/myCA/private : berisi private key 

Selanjutnya buat initial certificate database di ~/myCA subdirectory dengan perintah berikut,

cd ~/myCA
echo '01' > serial  && touch index.txt

Selanjutnya buat caconfig.cnf yang cocok untuk pembuatan CA certificate. Edit,

sudo vi ~/myCA/caconfig.cnf
sudo nano ~/myCA/caconfig.cnf

Isi dengan

# My sample caconfig.cnf file.
#
# Default configuration to use when one is not provided on the command line.
#
[ ca ]
default_ca      = local_ca
#
#
# Default location of directories and files needed to generate certificates.
#
[ local_ca ]
dir             = /home/<username>/myCA
certificate     = $dir/cacert.pem
database        = $dir/index.txt
new_certs_dir   = $dir/signedcerts
private_key     = $dir/private/cakey.pem
serial          = $dir/serial
#       
#
# Default expiration and encryption policies for certificates.
#
default_crl_days        = 365
default_days            = 1825
default_md              = sha1
#       
policy          = local_ca_policy
x509_extensions = local_ca_extensions
#
#
# Copy extensions specified in the certificate request
#
copy_extensions = copy
#       
#
# Default policy to use when generating server certificates.  The following
# fields must be defined in the server certificate.
#
[ local_ca_policy ]
commonName              = supplied
stateOrProvinceName     = supplied
countryName             = supplied
emailAddress            = supplied
organizationName        = supplied
organizationalUnitName  = supplied
#       
#
# x509 extensions to use when generating server certificates.
#
[ local_ca_extensions ]
basicConstraints        = CA:false
#       
#
# The default root certificate generation policy.
#
[ req ]
default_bits    = 2048
default_keyfile = /home/<username>/myCA/private/cakey.pem
default_md      = sha1
#       
prompt                  = no
distinguished_name      = root_ca_distinguished_name
x509_extensions         = root_ca_extensions
#
# 
# Root Certificate Authority distinguished name.  Change these fields to match
# your local environment!
#
[ root_ca_distinguished_name ]
commonName              = MyOwn Root Certificate Authority
stateOrProvinceName     = NC
countryName             = US
emailAddress            = root@tradeshowhell.com
organizationName        = Trade Show Hell
organizationalUnitName  = IT Department
#       
[ root_ca_extensions ]
basicConstraints        = CA:true

PENTING:

• Edit /home/<username>/ di bawah [ local_ca ] and [ req ] sesuai dengan username anda.
• Ubah commonName, stateOrProvinceName countryName dll di bawah [ root_ca_distinguished_name ] sesuai dengan kondisi anda.
• Untuk lebih jelasnya, baca2

man config

• Setelah selesai simpan di ~/myCA/caconfig.cnf.

Untuk mulai membuat Certificate Authority Root Certificate dan Key, lakukan ini pertama kali:

export OPENSSL_CONF=~/myCA/caconfig.cnf

Buat CA, dengan perintah

openssl req -x509 -newkey rsa:2048 -out cacert.pem -outform PEM -days 1825

You should be prompted for a passphrase, and see output similar to this:

Generating a 2048 bit RSA private key
............................................................................................+++
...........+++
writing new private key to '/home/onno/myCA/private/cakey.pem'
Enter PEM pass phrase:
Verifying - Enter PEM pass phrase:
-----

Jalan sampai lupa pass phrase yang digunakan! Kita akan membutuhkannya untuk men-generate dan sign server / client certificate!

Proses di atas akan membuat self-signed certificate menggunakan PEM format dan RSA public/private key encryption. Certificate akan valid untuk 1825 hari. Lokasi file yang dihasilkan adalah sebagai berikut,

~/myCA/cacert.pem : CA public certificate
~/myCA/private/cakey.pem : CA private key

Optional Step

Buang semua certificate dan hanya simpan bagian -CERTIFICATE- untuk membuat crt

openssl x509 -in cacert.pem -out cacert.crt

Creating a Self-Signed Server Certificate

Now that you have a Certificate Authority configured, you may use it to sign self-signed certificates. Prior to beginning the steps below, you may wish to encrypt the certificate's private key with a passphrase. The advantages of encrypting the key with a passphrase include protection of the certificate in the event it is stolen.

The certificate cannot be used with SSL-enabled applications without entering the passphrase every time the SSL-enabled application is started. This condition, while being most secure, can present a problem: If the server must be started in an unattended manner as in the case of a computer restart, then no one will be available to enter the passphrase, and subsequently the server will not start. One way to eliminate this condition involves a trade-off in security: The key may be decrypted, to remove the passphrase necessity; thus SSL-enabled applications will start automatically, without a need for you to enter a passphrase.

To actually generate a self-signed certificate for use with an SSL application, follow this process:

Create the server configuration file, by editing ~/myCA/exampleserver.cnf with your favorite text editor. Add this example content:

#
# exampleserver.cnf
#

[ req ]
prompt                  = no
distinguished_name      = server_distinguished_name
req_extensions          = v3_req

[ server_distinguished_name ]
commonName              = tradeshowhell.com
stateOrProvinceName     = NC
countryName             = US
emailAddress            = root@tradeshowhell.com
organizationName        = My Organization Name
organizationalUnitName  = Subunit of My Large Organization

[ v3_req ]
basicConstraints        = CA:FALSE
keyUsage                = nonRepudiation, digitalSignature, keyEncipherment
subjectAltName          = @alt_names

[ alt_names ]
DNS.0                   = tradeshowhell.com
DNS.1                   = alt.tradeshowhell.com

Be sure to change the values under server_distinguished_name especially the commonName value. The commonName value must match the host name, or CNAME for the host you wish to use the key for. If the commonName does not match the intended hostname, then host / certificate mismatch errors will appear in the client applications of clients attempting to access the server.

Once you've edited the file appropriately, save it as ~/myCA/exampleserver.cnf. Generate the server certificate, and key with the following commands:

export OPENSSL_CONF=~/myCA/exampleserver.cnf

The previous command sets an environment variable OPENSSL_CONF which forces the openssl tool to look for a configuration file in an alternative location (in this case, ~/myCA/exampleserver.cnf).

Now generate the certificate, and key:

openssl req -newkey rsa:1024 -keyout tempkey.pem -keyform PEM -out tempreq.pem -outform PEM

You should be prompted for a passphrase, and see output similar to this:

Generating a 1024 bit RSA private key
...++++++
...............++++++
writing new private key to 'tempkey.pem'
Enter PEM pass phrase:
Verifying - Enter PEM pass phrase:
-----

Don't forget the passphrase!

Next, you may translate the temporary private key into an unencrypted key by using the following command:

openssl rsa < tempkey.pem > server_key.pem

You should be prompted for the passphrase used above, and see the following output:

Enter pass phrase:
writing RSA key

If you wish to leave the key encrypted with a passphrase, simply rename the temporary key using the following command, instead of following the step above:

mv tempkey.pem server_key.pem

IconsPage/tip.png Remember: If you use a server key encrypted with a passphrase, the passphrase will have to be entered each time the server application using the encrypted key is started. This means the server application will not start unless someone, or something enters the key.

Now you need to sign the server certificate with the Certificate Authority (CA) key using these commands:

export OPENSSL_CONF=~/myCA/caconfig.cnf

The previous command modifies the environment variable OPENSSL_CONF which forces the openssl tool to look for a configuration file in an alternative location (in this case, ~/myCA/caconfig.cnf to switch back to the CA configuration).

Then sign the certificate as follows:

openssl ca -in tempreq.pem -out server_crt.pem

You will be prompted for the passphrase of the CA key as created in the Certificate Authority setup from above. Enter this passphrase at the prompt, and you will then be prompted to confirm the information in the exampleserver.cnf, and finally asked to confirm signing the certificate. Output should be similar to this:

Using configuration from /home/bshumate/myCA/caconfig.cnf
Enter pass phrase for /home/bshumate/myCA/private/cakey.pem:
Check that the request matches the signature
Signature ok
The Subject's Distinguished Name is as follows
commonName            :PRINTABLE:'tradeshowhell.com'
stateOrProvinceName   :PRINTABLE:'NC'
countryName           :PRINTABLE:'US'
emailAddress          :IA5STRING:'root@tradeshowhell.com'
organizationName      :PRINTABLE:'Trade Show Hell'
organizationalUnitName:PRINTABLE:'Black Ops'
Certificate is to be certified until Jan  4 21:50:08 2011 GMT (1825 days)
Sign the certificate? [y/n]:y
 

1 out of 1 certificate requests certified, commit? [y/n]y
Write out database with 1 new entries
Data Base Updated

Remove the temporary certificate, and key files with the following command:

rm -f tempkey.pem && rm -f tempreq.pem

Congratulations! You now have a self-signed server application certificate, and key pair:

server_crt.pem : Server application certificate file
server_key.pem : Server application key file 

Use the documentation provided with the server application you wish to use the certificate, and key for in order to properly use it. See the Configuring Apache for SSL Support section below for an example usage.

Optional Step for Certain Server Applications

Some server applications, such as the Courier IMAP mail server application require that the unencrypted private key be prepended to the server certificate. To accomplish this, simply enter the following commands:

cat server_key.pem server_crt.pem > hold.pem
mv      hold.pem server_crt.pem
chmod   400      server_crt.pem

Converting X.509 Certificates to PKCS#12 for Client Applications

If you wish to generate PKCS#12 certificates from your server's Root CA X.509 certificate for client use, you will need to use the following process on the particular server certificate, and key pair you desire to export a client certificate for:

Create a single file containing both the certificate, and key with the following command:

openssl req -x509 -nodes -days 365 -newkey rsa:1024 -keyout mycert.pem -out mycert.pem

Then, convert this certificate / key combination file into the PKCS#12 certificate with the following command:

openssl pkcs12 -export -out mycert.pfx -in mycert.pem -name "Certificate for Whatever"

You will be prompted for an Export password, which you may use, or just leave blank.

The resultant mycert.pfx file may now be imported into applications such as Web Browsers, and E-Mail clients. Since this certificate represents the Root CA certificate of your server, all subsequent server-level certificates signed by the CA certificate will also be automatically accepted by the client application which installs this PKCS#12 version of the certificate.

Generating Certificate for Signing by Recognized CA

In order to run a production server which will engage in commercial activity, such as "e-commerce", it is required to generate a certificate, and have it signed by a recognized Certificate Authority (CA) such as VeriSign. The process for generating a certificate request, and obtaining a certificate signed by a recognized CA can be difficult. You must complete all requisite "paperwork" prior to creating a certificate request, and ensure all required information is accurate.

Assuming you do not wish a passphrase-encrypted key, enter the following command to generate the private key, and certificate request:

openssl req -new -newkey rsa:1024 -nodes -keyout mykey.pem -out myreq.pem

If you already have a key you wish to use, then use the following command instead:

openssl req -new -key mykey.pem -out myreq.pem

You may wish to verify the signature, and information contained in the certificate request. Verify the signature with this command:

openssl req -in myreq.pem -noout -verify -key mykey.pem

and verify the information with this command:

openssl req -in myreq.pem -noout -text

The next steps typically involve pasting the content of the certificate request file into the CA's signup form, and awaiting the certificate. Also, you should safeguard the key file, as it will be required to use the certificate you receive from the CA.

Using PKCS#12 Certificates in Client Applications

This section of the guide explains using PKCS#12 certificates for SSL connections from the client perspective, and demonstrates the process of importing certificates into the Firefox Web Browser applications, and a couple of the more popular E-Mail clients.

Importation of a root certificate into such applications enables a trusted SSL-encrypted connection to the server from whence the certificate came, free of nagging messages about the certificate being self-signed, and so on.

Importing a Certificate into Mozilla Firefox

Importation of a PKCS#12 certificate into the Mozilla Firefox Web Browser application is very simple:

• From within Firefox, click Edit > Preferences
• Click the Advanced icon
• Click the View Certificates button
• Click the Import button
• Browse to the location of the certificate file, which is typically a .pfx file type
• Highlight the certificate file, and click the Open button

You may be prompted to enter Firefox's Master Password at this point, or to set an initial Master Password. Enter the current, or net password as required, confirm it, and click OK

You will then be prompted to enter the certificate's Export password. If there is no such password attached to the certificate, simply click OK, otherwise enter the password, and click OK A message will appear advising that Firefox has "Successfully restored your security certificate(s) and private key(s)"

   Click OK
   You have successfully imported the server's client PKCS#12 certificate into Firefox 

Importing a Certificate into Evolution

Importation of a PKCS#12 certificate into the Evolution E-Mail client couldn't be simpler:

• From within Evolution, click Edit > Preferences
• Click the Certificates icon
• Click the Import button
• Browse to the location of the certificate file, which is typically a .pfx file type
• Highlight the certificate file, and click the Open button

You may be prompted to enter Evolution's certificate database password at this point, or to set an initial certificate database password. Enter the current, or new password as required, confirm it, and click OK

You will then be prompted to enter the PKCS12 File Password. If there is no such password attached to the certificate, simply click OK, otherwise enter the password, and click OK

You should see the certificate, and its details appear in the Your Certificates section of the Evolution Settings window

   Click the Close button
   You have successfully imported the server's client PKCS#12 certificate into Evolution 

Importing a Certificate into Mozilla Thunderbird

Importation of a PKCS#12 certificate into the Mozilla Thunderbird E-Mail client application is very simple:

• From within Thunderbird, click Edit > Preferences
• Click the Advanced icon
• Click the Certificates entry in the right pane
• Click the Manage Certificates button
• Click the Import button
• Browse to the location of the certificate file, which is typically a .pfx file type
• Highlight the certificate file, and click the Open button

You may be prompted to enter Thunderbird's Master Password at this point, or to set an initial Master Password. Enter the current, or new password as required, confirm it, and click OK

You will then be prompted to enter the certificate's Export password. If there is no such password attached to the certificate, simply click OK, otherwise enter the password, and click OK A message will appear advising that Thunderbird has "Successfully restored your security certificate(s) and private key(s)"

   Click OK
   You have successfully imported the server's client PKCS#12 certificate into Thunderbird 

Importing a Certificate into the System-Wide Certificate Authority Database

You can import a CA Certificate into the system-wide database of trusted certificate authorities. Applications that use this database will automatically trust any certificates stored here.

1. Copy your certificate to the system certificate directory. At a terminal prompt, type:

$ sudo cp mycert.pem /usr/share/ca-certificates/mycert.crt

2. Edit the ca-certificates configuration file /etc/ca-certificates.conf. Add the name of the file you copied to /usr/share/ca-certificates to the top of the list just after the final "#". For example:

# This file lists certificates that you wish to use or to ignore to be
# installed in /etc/ssl/certs.
# update-ca-certificates(8) will update /etc/ssl/certs by reading this file.
#
# This is autogenerated by dpkg-reconfigure ca-certificates.
# certificates shoule be installed under /usr/share/ca-certificates
# and files with extension '.crt' is recognized as available certs.
#
# line begins with # is comment.
# line begins with ! is certificate filename to be deselected.
#
mycert.crt
brasil.gov.br/brasil.gov.br.crt
cacert.org/cacert.org.crt
mozilla/ABAecom_=sub.__Am._Bankers_Assn.=_Root_CA.crt
[... many additional certificates omitted ...]

Instead of manually editing this file, you can run

sudo dpkg-reconfigure ca-certificates

3. Update the CA certificates database by typing:

$ sudo update-ca-certificates

4. You have successfully imported your certificate into the system CA certificates database.

Configuring Apache for SSL Support

To configure Apache2 for HTTPS and generate a certificate, follow the instructions in Server Guide - HTTPD and Server Guide - Certificates.

Resources

Additional resources pertaining to OpenSSL and Secure Sockets Layer appear below.

Local System Resources

man config

System manual page for the OpenSSL library configuration files

man gendsa

System manual page for the gendsa DSA private key generator

man genrsa

System manual page for the genrsa RSA private key generator

man openssl

System manual page for the openssl command-line tool

man rand

System manual page for the rand pseudo-random byte generator utility

man x509

System manual page for the x509 certificate display and signing utility

Referensi

• https://help.ubuntu.com/community/OpenSSL