EASY-RSA Version 2.0-rc1 This is a small RSA key management package, based on the openssl command line tool, that can be found in the easy-rsa subdirectory of the OpenVPN distribution. These are reference notes. For step-by-step instructions, see the HOWTO: http://openvpn.net/howto.html This package is based on the ./pkitool script. Run ./pkitool without arguments for a detailed help message (which is also pasted below). Release Notes for easy-rsa-2.0 * Most functionality has been consolidated into the pkitool script. For compatibility, all previous scripts from 1.0 such as build-key and build-key-server are provided as stubs which call pkitool to do the real work. * pkitool has a --batch flag (enabled by default) which generates keys/certs without needing any interactive input. pkitool can still generate certs/keys using interactive prompting by using the --interact flag. * The inherit-inter script has been provided for creating a new PKI rooted on an intermediate certificate built within a higher-level PKI. See comments in the inherit-inter script for more info. * The openssl.cnf file has been modified. pkitool will not work with the openssl.cnf file included with previous easy-rsa releases. * The vars file has been modified -- the following extra variables have been added: EASY_RSA, CA_EXPIRE, KEY_EXPIRE. * The make-crl and revoke-crt scripts have been removed and are replaced by the revoke-full script. * The "Organizational Unit" X509 field can be set using the KEY_OU environmental variable before calling pkitool. * This release only affects the Linux/Unix version of easy-rsa. The Windows version (written to use the Windows shell) is unchanged. INSTALL easy-rsa 1. Edit vars. 2. Set KEY_CONFIG to point to the openssl.cnf file included in this distribution. 3. Set KEY_DIR to point to a directory which will contain all keys, certificates, etc. This directory need not exist, and if it does, it will be deleted with rm -rf, so BE CAREFUL how you set KEY_DIR. 4. (Optional) Edit other fields in vars per your site data. You may want to increase KEY_SIZE to 2048 if you are paranoid and don't mind slower key processing, but certainly 1024 is fine for testing purposes. KEY_SIZE must be compatible across both peers participating in a secure SSL/TLS connection. 5 . vars 6. ./clean-all 7. As you create certificates, keys, and certificate signing requests, understand that only .key files should be kept confidential. .crt and .csr files can be sent over insecure channels such as plaintext email. IMPORTANT To avoid a possible Man-in-the-Middle attack where an authorized client tries to connect to another client by impersonating the server, make sure to enforce some kind of server certificate verification by clients. There are currently four different ways of accomplishing this, listed in the order of preference: (1) Build your server certificates with the build-key-server script, or using the --server option to pkitool. This will designate the certificate as a server-only certificate by setting nsCertType=server. Now add the following line to your client configuration: ns-cert-type server This will block clients from connecting to any server which lacks the nsCertType=server designation in its certificate, even if the certificate has been signed by the CA which is cited in the OpenVPN configuration file (--ca directive). (2) Use the --tls-remote directive on the client to accept/reject the server connection based on the common name of the server certificate. (3) Use a --tls-verify script or plugin to accept/reject the server connection based on a custom test of the server certificate's embedded X509 subject details. (4) Sign server certificates with one CA and client certificates with a different CA. The client config "ca" directive should reference the server-signing CA while the server config "ca" directive should reference the client-signing CA. NOTES Show certificate fields: openssl x509 -in cert.crt -text PKITOOL documentation pkitool 2.0 Usage: pkitool [options...] [common-name] Options: --batch : batch mode (default) --interact : interactive mode --server : build server cert --initca : build root CA --inter : build intermediate CA --pass : encrypt private key with password --csr : only generate a CSR, do not sign --sign : sign an existing CSR --pkcs12 : generate a combined pkcs12 file Notes: Please edit the vars script to reflect your configuration, then source it with "source ./vars". Next, to start with a fresh PKI configuration and to delete any previous certificates and keys, run "./clean-all". Finally, you can run this tool (pkitool) to build certificates/keys. Generated files and corresponding OpenVPN directives: (Files will be placed in the $KEY_DIR directory, defined in ./vars) ca.crt -> root certificate (--ca) ca.key -> root key, keep secure (not directly used by OpenVPN) .crt files -> client/server certificates (--cert) .key files -> private keys, keep secure (--key) .csr files -> certificate signing request (not directly used by OpenVPN) dh1024.pem or dh2048.pem -> Diffie Hellman parameters (--dh) Examples: pkitool --initca -> Build root certificate pkitool --initca --pass -> Build root certificate with password-protected key pkitool --server server1 -> Build "server1" certificate/key pkitool client1 -> Build "client1" certificate/key pkitool --pass client2 -> Build password-protected "client2" certificate/key pkitool --pkcs12 client3 -> Build "client3" certificate/key in PKCS #12 format pkitool --csr client4 -> Build "client4" CSR to be signed by another CA pkitool --sign client4 -> Sign "client4" CSR pkitool --inter interca -> Build an intermediate key-signing certificate/key Also see ./inherit-inter script. Typical usage for initial PKI setup. Build myserver, client1, and client2 cert/keys. Protect client2 key with a password. Build DH parms. Generated files in ./keys : [edit vars with your site-specific info] source ./vars ./clean-all ./build-dh -> takes a long time, consider backgrounding ./pkitool --initca ./pkitool --server myserver ./pkitool client1 ./pkitool --pass client2 Typical usage for adding client cert to existing PKI: source ./vars ./pkitool client-new