test: cover pkg/ssh key management

pkg/ssh/keys_test.go

@@ -0,0 +1,116 @@
+package ssh
+
+import (
+	"crypto/rsa"
+	"encoding/base64"
+	"encoding/pem"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/crypto/ssh"
+)
+
+func TestGetPrivateKeyRawBase_GeneratesValidKeyPair(t *testing.T) {
+	dir := t.TempDir()
+
+	raw, err := GetPrivateKeyRawBase(dir)
+	require.NoError(t, err)
+
+	block, _ := pem.Decode(raw)
+	require.NotNil(t, block, "private key must be valid PEM")
+	assert.Equal(t, "RSA PRIVATE KEY", block.Type)
+
+	info, err := os.Stat(filepath.Join(dir, DevsySSHPrivateKeyFile))
+	require.NoError(t, err)
+	assert.Equal(t, os.FileMode(0o600), info.Mode().Perm(),
+		"private key file must be 0600")
+
+	pubInfo, err := os.Stat(filepath.Join(dir, DevsySSHPublicKeyFile))
+	require.NoError(t, err)
+	assert.Equal(t, os.FileMode(0o644), pubInfo.Mode().Perm(),
+		"public key file must be 0644")
+}
+
+func TestGetPrivateKeyRawBase_IdempotentAcrossCalls(t *testing.T) {
+	dir := t.TempDir()
+
+	first, err := GetPrivateKeyRawBase(dir)
+	require.NoError(t, err)
+
+	second, err := GetPrivateKeyRawBase(dir)
+	require.NoError(t, err)
+
+	assert.Equal(t, first, second, "existing key pair must not be regenerated")
+}
+
+func TestGetPublicKeyBase_ReturnsParseableAuthorizedKey(t *testing.T) {
+	dir := t.TempDir()
+
+	encoded, err := GetPublicKeyBase(dir)
+	require.NoError(t, err)
+
+	decoded, err := base64.StdEncoding.DecodeString(encoded)
+	require.NoError(t, err)
+
+	pubKey, _, _, _, err := ssh.ParseAuthorizedKey(decoded)
+	require.NoError(t, err)
+	assert.Equal(t, ssh.KeyAlgoRSA, pubKey.Type())
+}
+
+func TestGetPublicKeyBase_ConsistentWithPrivateKey(t *testing.T) {
+	dir := t.TempDir()
+
+	privRaw, err := GetPrivateKeyRawBase(dir)
+	require.NoError(t, err)
+
+	privAny, err := ssh.ParseRawPrivateKey(privRaw)
+	require.NoError(t, err)
+
+	encoded, err := GetPublicKeyBase(dir)
+	require.NoError(t, err)
+
+	decoded, err := base64.StdEncoding.DecodeString(encoded)
+	require.NoError(t, err)
+
+	pubKey, _, _, _, err := ssh.ParseAuthorizedKey(decoded)
+	require.NoError(t, err)
+
+	priv, ok := privAny.(*rsa.PrivateKey)
+	require.True(t, ok, "parsed private key must be RSA")
+
+	expected, err := ssh.NewPublicKey(priv.Public())
+	require.NoError(t, err)
+
+	assert.Equal(t, expected.Marshal(), pubKey.Marshal(),
+		"public key must correspond to the generated private key")
+}
+
+func TestGetHostKeyBase_GeneratesAndIsIdempotent(t *testing.T) {
+	dir := t.TempDir()
+
+	first, err := GetHostKeyBase(dir)
+	require.NoError(t, err)
+	assert.NotEmpty(t, first, "host key must not be empty")
+
+	info, err := os.Stat(filepath.Join(dir, DevsySSHHostKeyFile))
+	require.NoError(t, err)
+	assert.Equal(t, os.FileMode(0o600), info.Mode().Perm(),
+		"host key file must be 0600")
+
+	second, err := GetHostKeyBase(dir)
+	require.NoError(t, err)
+	assert.Equal(t, first, second, "existing host key must not be regenerated")
+}
+
+func TestGetPrivateKeyRawBase_CreatesMissingDirectory(t *testing.T) {
+	nested := filepath.Join(t.TempDir(), "does", "not", "exist")
+
+	_, err := GetPrivateKeyRawBase(nested)
+	require.NoError(t, err)
+
+	_, err = os.Stat(nested)
+	assert.NoError(t, err, "base directory must be created when missing")
+}