test identity file parsing

communicator/ssh/ssh_test.go

@@ -0,0 +1,105 @@
+package ssh
+
+import (
+	"bytes"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"golang.org/x/crypto/ssh"
+)
+
+// verify that we can locate public key data
+func TestFindKeyData(t *testing.T) {
+	// setup a test directory
+	td, err := ioutil.TempDir("", "ssh")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(td)
+	cwd, err := os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Chdir(td); err != nil {
+		t.Fatal(err)
+	}
+	defer os.Chdir(cwd)
+
+	id := "provisioner_id"
+
+	pub := generateSSHKey(t, id)
+	pubData := pub.Marshal()
+
+	// backup the pub file, and replace it with a broken file to ensure we
+	// extract the public key from the private key.
+	if err := os.Rename(id+".pub", "saved.pub"); err != nil {
+		t.Fatal(err)
+	}
+	if err := ioutil.WriteFile(id+".pub", []byte("not a public key"), 0600); err != nil {
+		t.Fatal(err)
+	}
+
+	foundData := findIDPublicKey(id)
+	if !bytes.Equal(foundData, pubData) {
+		t.Fatalf("public key %q does not match", foundData)
+	}
+
+	// move the pub file back, and break the private key file to simulate an
+	// encrypted private key
+	if err := os.Rename("saved.pub", id+".pub"); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := ioutil.WriteFile(id, []byte("encrypted private key"), 0600); err != nil {
+		t.Fatal(err)
+	}
+
+	foundData = findIDPublicKey(id)
+	if !bytes.Equal(foundData, pubData) {
+		t.Fatalf("public key %q does not match", foundData)
+	}
+
+	// check the file by path too
+	foundData = findIDPublicKey(filepath.Join(".", id))
+	if !bytes.Equal(foundData, pubData) {
+		t.Fatalf("public key %q does not match", foundData)
+	}
+}
+
+func generateSSHKey(t *testing.T, idFile string) ssh.PublicKey {
+	t.Helper()
+
+	priv, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	privFile, err := os.OpenFile(idFile, os.O_RDWR|os.O_CREATE, 0600)
+	defer privFile.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+	privPEM := &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)}
+	if err := pem.Encode(privFile, privPEM); err != nil {
+		t.Fatal(err)
+	}
+
+	// generate and write public key
+	pub, err := ssh.NewPublicKey(&priv.PublicKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = ioutil.WriteFile(idFile+".pub", ssh.MarshalAuthorizedKey(pub), 0600)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return pub
+}