latchset/custodia.ipa

FreeIPA vault plugin for Custodia

custodia.ipa — IPA vault plugin for Custodia

WARNING custodia.ipa is a tech preview with a provisional API.

custodia.ipa is a collection of plugins for Custodia. It provides integration with FreeIPA. The IPAVault plugin is an interface to FreeIPA vault. Secrets are encrypted and stored in Dogtag's Key Recovery Agent. The IPACertRequest plugin creates private key and signed certificates on-demand. Finally the IPAInterface plugin is a helper plugin that wraps ipalib and GSSAPI authentication.

Requirements

Installation

• pip
• setuptools >= 18.0

Runtime

• custodia >= 0.5.0
• ipalib >= 4.5.0
• ipaclient >= 4.5.0
• Python 2.7 (Python 3 support in IPA vault is unstable.)

custodia.ipa requires an IPA-enrolled host and a Kerberos TGT for authentication. It is recommended to provide credentials with a keytab file or GSS-Proxy. Furthermore IPAVault depends on Key Recovery Agent service (ipa-kra-install).

Testing and development

• wheel
• tox

virtualenv requirements

custodia.ipa depends on several binary extensions and shared libraries for e.g. python-cryptography, python-gssapi, python-ldap, and python-nss. For installation in a virtual environment, a C compiler and several development packages are required.

$ virtualenv venv
$ venv/bin/pip install --upgrade custodia.ipa

Fedora

$ sudo dnf install python2 python-pip python-virtualenv python-devel \
    gcc redhat-rpm-config krb5-workstation krb5-devel libffi-devel \
    nss-devel openldap-devel cyrus-sasl-devel openssl-devel

Debian / Ubuntu

$ sudo apt-get update
$ sudo apt-get install -y python2.7 python-pip python-virtualenv python-dev \
    gcc krb5-user libkrb5-dev libffi-dev libnss3-dev libldap2-dev \
    libsasl2-dev libssl-dev

---

Example configuration

Create directories

$ sudo mkdir /etc/custodia /var/lib/custodia /var/log/custodia /var/run/custodia
$ sudo chown USER:GROUP /var/lib/custodia /var/log/custodia /var/run/custodia
$ sudo chmod 750 /var/lib/custodia /var/log/custodia

Create service account and keytab

$ kinit admin
$ ipa service-add custodia/$HOSTNAME
$ ipa service-allow-create-keytab custodia/$HOSTNAME --users=admin
$ mkdir -p /etc/custodia
$ ipa-getkeytab -p custodia/$HOSTNAME -k /etc/custodia/ipa.keytab
$ chown custodia:custodia /etc/custodia/ipa.keytab

The IPA cert request plugin needs additional permissions

$ ipa privilege-add \
    --desc="Create and request service certs with Custodia" \
    "Custodia Service Certs"
$ ipa privilege-add-permission \
    --permissions="Retrieve Certificates from the CA" \
    --permissions="Request Certificate" \
    --permissions="Revoke Certificate" \
    --permissions="System: Modify Services" \
    "Custodia Service Certs"
# for add_principal=True
$ ipa privilege-add-permission \
    --permissions="System: Add Services" \
    "Custodia Service Certs"
$ ipa role-add \
    --desc="Create and request service certs with Custodia" \
    "Custodia Service Cert Adminstrator"
$ ipa role-add-privilege \
    --privileges="Custodia Service Certs" \
    "Custodia Service Cert Adminstrator"
$ ipa role-add-member \
    --services="custodia/$HOSTNAME" \
    "Custodia Service Cert Adminstrator"

Create /etc/custodia/ipa.conf

# /etc/custodia/ipa.conf

[global]
debug = true
makedirs = true

[auth:ipa]
handler = IPAInterface
keytab = ${configdir}/${instance}.keytab
ccache = FILE:${rundir}/ccache

[auth:creds]
handler = SimpleCredsAuth
uid = root
gid = root

[authz:paths]
handler = SimplePathAuthz
paths = /. /secrets

[store:vault]
handler = IPAVault

[store:cert]
handler = IPACertRequest
backing_store = vault

[/]
handler = Root

[/secrets]
handler = Secrets
store = vault

[/secrets/certs]
handler = Secrets
store = cert

Run Custodia server

$ systemctl start [email protected]

IPA cert request

The IPACertRequest store plugin generates or revokes certificates on the fly. It uses a backing store to cache certs and private keys. The plugin can create service principal automatically. However the host must already exist. The IPACertRequest does not create host entries on demand.

A request like GET /path/to/store/HTTP/client1.ipa.example generates a private key and CSR for the service HTTP/client1.ipa.example with DNS subject alternative name client1.ipa.example. The CSR is then forwarded to IPA and signed by Dogtag. The resulting cert and its trust chain is returned together with the private key as a PEM bundle.

$ export CUSTODIA_INSTANCE=ipa
$ custodia-cli get /certs/HTTP/client1.ipa.example
-----BEGIN RSA PRIVATE KEY-----
...
-----END RSA PRIVATE KEY-----

Issuer: organizationName=IPA.EXAMPLE, commonName=Certificate Authority
Subject: organizationName=IPA.EXAMPLE, commonName=client1.ipa.example
Serial Number: 22
Validity:
    Not Before: 2017-04-27 09:44:20
    Not After: 2019-04-28 09:44:20
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----

Issuer: organizationName=IPA.EXAMPLE, commonName=Certificate Authority
Issuer: organizationName=IPA.EXAMPLE, commonName=Certificate Authority
Serial Number: 1
Validity:
    Not Before: 2017-04-26 08:24:11
    Not After: 2037-04-26 08:24:11
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----

A DELETE request removes the cert/key pair from the backing store and revokes the cert at the same time.

Automatical renewal of revoked or expired certificates is not implemented yet.

FreeIPA 4.4 support

The default settings and permissions are tuned for FreeIPA >= 4.5. For 4.4, the plugin must be configured with chain=False. The additional permission Request Certificate with SubjectAltName is required, too.

ipa privilege-add-permission \
    --permissions="Request Certificate with SubjectAltName" \
    "Custodia Service Certs"