certs

Generate test certificates for Go programs.

Basic Usage

Grab a copy of the package:

go get github.com/dmjones/certs

Simple certificates can be created using Cert, CertDER and CertPEM:

cert, key, err := certs.New()           // returns *x509.Certificate and crypto.Signer
certDER, keyDER, err := certs.NewDER()  // returns DER-encoded
certPEM, keyPEM, err := certs.NewPEM()  // returns PEM-encoded

These certificate will have default properties, including:

• Self-signed (using SHA256WithRSA)
• RSA 2048-bit keys
• One year validity
• Random serial number
• Random Common Name (all other DN fields blank)

These properties can be overriden. See examples below, or the docs for the Config class for more details.

Avoid the error check

In a testing environment, you can avoid checking for the error by using the equivalent TNew, TNewDER and TNewPEM functions:

func TestSomething(t *testing.T) {
    cert, key, err := certs.TNew(t)           // returns *x509.Certificate and crypto.Signer
    certDER, keyDER, err := certs.TNewDER(t)  // returns DER-encoded
    certPEM, keyPEM, err := certs.TNewPEM(t)  // returns PEM-encoded
}

Save to file

If you need to save to file, pass a Config argument and provide either (or both) of CertPath and KeyPath:

cert, key, err := certs.New(certs.Config{CertPath: "/tmp/cert.cert", KeyPath: "/tmp/key.pem"})

Override defaults

Pass a Config argument to override the default settings. You only need to specify the elements you wish to override. Below is an example that overrides every supported setting:

cfg := certs.Config{
    CACert: otherCert,
    CAKey:  otherKey,
    DN: &pkix.Name{
        Country:            []string{"GB"},
        Organization:       []string{"org"},
        OrganizationalUnit: []string{"ou"},
        CommonName:         "foo",
    },
    Expiry:       time.Now().AddDate(0, 2, 5),
    SerialNumber: big.NewInt(42),
    KeyType:      certs.ECDSA,
    RSAKeySize:   0,
    Curve:        elliptic.P384(),
    IsCA:         true,
    Algorithm:    x509.ECDSAWithSHA384,
}

cert, key, err := certs.New(cfg)