Certificatetest

1. Hardening the Security

The ZNC acts as proxy for the irc connection, so the ZNC will manage 2 kind of connections: - IRC client <-> ZNC - ZNC <-> IRC Server

To increase our security we want that both of them use SSL layer; otherwise the information will be securized only on the side with the SSL in use and totally undecure on the other side, and this means: garbage in - garbage out.

Before to proceed we have to be sure that the ZNC has been compiled with SSL support.

To do this (ask..)

1. 1. ZNC Config

As reported in the Configuration we have a couple of security options.

(Ask if split pem or keep it single)

Another important configuration is the keyxchange. The defaults are perfectly fine but if you are security paranoid and your clients support latest EC (elliptic curve) algos, you can push them yo accept only XXXX

1. 1. Certificate

Copy the certificate instructions

1. 1. IRC Client connection

As first connection we are going to manage the IRC Client <-> ZNC one. First step is the enabling of the SSL port directly on first configuration. Otherwise we can proceed enabling via WebAdmin panel or via command line.

1. 1. 1. Web Admin Page

Screenshot

1. 1. 1. Command line

Run this command (Check command)

Now we have to configure our clients to use the SSL on connection. The second optional step is to use the Cert

The scope of this page is to be the compendium for all the commands required to manage ZNC's certificates.

Algorithms

The Public Key Infrastructures (PKI) are based on asymmetric cryptography principles: public & private key.

There are 3 primary algorithms used for PKI key generation:

• (ECC) Elliptic Curve Cryptography

It is the most recently-developed encryption method of the three, but it is going to be more supported. With shorter key lengths, it provides equivalent levels of cryptographic strength as RSA and DSA.

• (RSA) Rivest-Shamir-Adleman

The RSA algorithm was developed in 1977 by Ron Rivest, Adi Shamir, and Leonard Adleman. It is currently the most used and supported key algorithm. Nowadays the key length standard is 2048-4096 bits.

• (DSA) Digital Signature Algorithm

It uses a different algorithm than RSA to create public/private keys but both are considered to be equivalent at same key length. The main differences come down to performance, speed and adoption by the market. Moreover some software are limited to manage DSA up to 1024 bits.

Algorithms Key Size Comparison (bits)
Symmetric	RSA/DSA	ECC
80	1024	160-223
112	2048	224-255
128	3072	256-383
192	7680	384-511
256	15360	512+

Taking in consideration the current security standards, we will continue using ECC and RSA.

Key generation

The first step is to create a key pair. As described before, we will provide commands to create ECC or RSA keys.

WARNING: The folllowing commands will not encrypt/password protect the private key cause ZNC is unable to properly handle encrypted private key files. For this reason keep it secret.

Before to proceed, if you want to adopt the ECC, check 2 constraints:
* Your IRC Client supports ECC
* In the case you want certificates signed by a global CA, be sure it supports ECC
If any of these 2 points will be a NO, then use the RSA.

Regarderless the algorithm you choose, at the end of the process you will have:

• 1 priv.key
• 1 pub.key
• 1 priv.info (optional)

ECC

# Generate the ECC private key with 256-bit key length
openssl ecparam -genkey -name prime256v1 -outform PEM -out priv.key
# Generate the ECC public key
openssl ec -outform PEM -pubout -in priv.key -out pub.key
# Get information on the ECC private key
openssl ecparam -noout -text -in priv.key
# Get sensitive information on the ECC private key
openssl ecparam -noout -text -in priv.key -param_enc explicit

On last 2 commands you can add -out priv.info to get information stored on a file

RSA

# Generate the RSA private key with 4096-bit key length
openssl genrsa -out priv.key 4096
# Generate the RSA public key
openssl rsa -outform PEM -pubout -in priv.key -out rsa.pub.key
# Get sensitive information on the RSA private key
openssl rsa -noout -text -in priv.key

On last command you can add -out priv.info to get information stored on a file

Certificate generation

Certificate Signing Request

The requirement to have a Certificate is to create a Certificate Signing Request (CSR). The command is the same for ECC and RSA keys.

openssl req -new -sha512 -key priv.key -out cert.csr

If -subj "/CN=YourNickname"

• For a RSA based certificate, with 4096-bit key length:

# Generate the rsa private key and the certificate embeded in same file for ZNC's YourNickname:
openssl req -nodes -sha512 -newkey rsa:4096 -keyout user.pem -x509 -days 3650 -out user.pem -subj "/CN=YourNickname"

• For an ECC based certificate, with 256-bit key length:

# Generate the ecc private key:
openssl ecparam -genkey -name prime256v1 -out user.key
# Generate the Certificate Signing Request (CSR) for ZNC's YourNickname:
openssl req -new -sha512 -key user.key -out user.csr -subj "/CN=YourNickname"
# Submit the CSR to a CA or selfsign it yourself with:
openssl req -x509 -sha512 -days 3650 -key user.key -in user.csr -out user.crt
# Embed private key and certificate in same file as requested in many cases:
cat user.crt user.key > user.pem

Glossary

• Certificate: Also known as X.509 certificate, it is used to encrypt and decrypt data relaying on a related public and private key pair.
• CSR: Certificate Signing Request
• DSA: Digital Signature Algorithm
• ECC: Elliptic Curve Cryptography algorithms
• RSA: Rivest-Shamir-Adleman algorithms
• PKI: Public Key Infrastructures
• Private Key: One of the key pair. It is the one that must be kept secret
• PEM: Privacy Enhanced Mail - a Base64 encoded ASCII file format
• Public Key: One of the key pair. It is the one that can be freely shared
• P12: Common file extension for PKCS#12 format
• PFX: Common file extension for PKCS#12 format
• PCKS12: Common file extension for PKCS#12 format
• PKCS#12: Binary format for storing certificate chain and private key in a single: encryptable file