fix(settings): read PEM files but b64 env vars

- Extract base64 data from PEM files and secret files
- Environment variables are not PEM encoded and only the base64 data
- Affects OpenVPN certificate, key and encrypted key

internal/configuration/settings/openvpn.go

@@ -1,6 +1,7 @@
 package settings
 
 import (
+	"encoding/base64"
 	"fmt"
 	"regexp"
 	"strings"
@@ -193,7 +194,7 @@ func validateOpenVPNClientCertificate(vpnProvider,
 		return nil
 	}
 
-	_, err = extract.PEM([]byte(clientCert))
+	_, err = base64.StdEncoding.DecodeString(clientCert)
 	if err != nil {
 		return err
 	}
@@ -215,7 +216,7 @@ func validateOpenVPNClientKey(vpnProvider, clientKey string) (err error) {
 		return nil
 	}
 
-	_, err = extract.PEM([]byte(clientKey))
+	_, err = base64.StdEncoding.DecodeString(clientKey)
 	if err != nil {
 		return err
 	}
@@ -232,9 +233,9 @@ func validateOpenVPNEncryptedKey(vpnProvider,
 		return nil
 	}
 
-	_, err = extract.PEM([]byte(encryptedPrivateKey))
+	_, err = base64.StdEncoding.DecodeString(encryptedPrivateKey)
 	if err != nil {
-		return fmt.Errorf("extracting encrypted key: %w", err)
+		return err
 	}
 	return nil
 }