From 2c30984a10bd0667a715fbd5f77b268a58a0af42 Mon Sep 17 00:00:00 2001
From: Quentin McGaw <quentin.mcgaw@gmail.com>
Date: Tue, 30 May 2023 12:46:10 +0000
Subject: [PATCH] hotfix(env): read some settings with case sensitivity

---
 internal/configuration/sources/env/dns.go     |  2 +-
 .../configuration/sources/env/dnsblacklist.go |  2 +-
 .../configuration/sources/env/firewall.go     |  2 +-
 internal/configuration/sources/env/health.go  |  4 +--
 internal/configuration/sources/env/helpers.go |  4 +--
 .../configuration/sources/env/httproxy.go     | 16 ++++++++----
 internal/configuration/sources/env/openvpn.go | 26 +++++++++++--------
 .../sources/env/openvpnselection.go           |  6 ++---
 .../configuration/sources/env/portforward.go  | 19 ++++++++------
 .../configuration/sources/env/provider.go     |  2 +-
 .../configuration/sources/env/publicip.go     |  3 ++-
 internal/configuration/sources/env/reader.go  |  6 ++---
 internal/configuration/sources/env/server.go  |  3 ++-
 .../sources/env/serverselection.go            | 14 +++++-----
 .../configuration/sources/env/shadowsocks.go  |  9 ++++---
 internal/configuration/sources/env/system.go  |  2 +-
 .../configuration/sources/env/wireguard.go    | 10 ++++---
 .../sources/env/wireguardselection.go         |  6 ++---
 18 files changed, 78 insertions(+), 58 deletions(-)

diff --git a/internal/configuration/sources/env/dns.go b/internal/configuration/sources/env/dns.go
index 745d6814..a6c2f987 100644
--- a/internal/configuration/sources/env/dns.go
+++ b/internal/configuration/sources/env/dns.go
@@ -27,7 +27,7 @@ func (s *Source) readDNS() (dns settings.DNS, err error) {
 }
 
 func (s *Source) readDNSServerAddress() (address netip.Addr, err error) {
-	key, value := s.getEnvWithRetro("DNS_ADDRESS", "DNS_PLAINTEXT_ADDRESS")
+	key, value := s.getEnvWithRetro("DNS_ADDRESS", []string{"DNS_PLAINTEXT_ADDRESS"})
 	if value == "" {
 		return address, nil
 	}
diff --git a/internal/configuration/sources/env/dnsblacklist.go b/internal/configuration/sources/env/dnsblacklist.go
index da83d6af..573026c3 100644
--- a/internal/configuration/sources/env/dnsblacklist.go
+++ b/internal/configuration/sources/env/dnsblacklist.go
@@ -37,7 +37,7 @@ func (s *Source) readDNSBlacklist() (blacklist settings.DNSBlacklist, err error)
 }
 
 func (s *Source) readBlockSurveillance() (blocked *bool, err error) {
-	key, value := s.getEnvWithRetro("BLOCK_SURVEILLANCE", "BLOCK_NSA")
+	key, value := s.getEnvWithRetro("BLOCK_SURVEILLANCE", []string{"BLOCK_NSA"})
 	blocked, err = binary.Validate(value)
 	if err != nil {
 		return nil, fmt.Errorf("environment variable %s: %w", key, err)
diff --git a/internal/configuration/sources/env/firewall.go b/internal/configuration/sources/env/firewall.go
index 5c9e625a..60a775a0 100644
--- a/internal/configuration/sources/env/firewall.go
+++ b/internal/configuration/sources/env/firewall.go
@@ -22,7 +22,7 @@ func (s *Source) readFirewall() (firewall settings.Firewall, err error) {
 		return firewall, fmt.Errorf("environment variable FIREWALL_INPUT_PORTS: %w", err)
 	}
 
-	outboundSubnetsKey, _ := s.getEnvWithRetro("FIREWALL_OUTBOUND_SUBNETS", "EXTRA_SUBNETS")
+	outboundSubnetsKey, _ := s.getEnvWithRetro("FIREWALL_OUTBOUND_SUBNETS", []string{"EXTRA_SUBNETS"})
 	outboundSubnetStrings := envToCSV(outboundSubnetsKey)
 	firewall.OutboundSubnets, err = stringsToNetipPrefixes(outboundSubnetStrings)
 	if err != nil {
diff --git a/internal/configuration/sources/env/health.go b/internal/configuration/sources/env/health.go
index bcae65df..4e8f4ac1 100644
--- a/internal/configuration/sources/env/health.go
+++ b/internal/configuration/sources/env/health.go
@@ -10,7 +10,7 @@ import (
 
 func (s *Source) ReadHealth() (health settings.Health, err error) {
 	health.ServerAddress = env.Get("HEALTH_SERVER_ADDRESS")
-	_, health.TargetAddress = s.getEnvWithRetro("HEALTH_TARGET_ADDRESS", "HEALTH_ADDRESS_TO_PING")
+	_, health.TargetAddress = s.getEnvWithRetro("HEALTH_TARGET_ADDRESS", []string{"HEALTH_ADDRESS_TO_PING"})
 
 	successWaitPtr, err := envToDurationPtr("HEALTH_SUCCESS_WAIT_DURATION")
 	if err != nil {
@@ -37,7 +37,7 @@ func (s *Source) ReadHealth() (health settings.Health, err error) {
 }
 
 func (s *Source) readDurationWithRetro(envKey, retroEnvKey string) (d *time.Duration, err error) {
-	envKey, value := s.getEnvWithRetro(envKey, retroEnvKey)
+	envKey, value := s.getEnvWithRetro(envKey, []string{retroEnvKey})
 	if value == "" {
 		return nil, nil //nolint:nilnil
 	}
diff --git a/internal/configuration/sources/env/helpers.go b/internal/configuration/sources/env/helpers.go
index 8c0d18f0..9761ef5c 100644
--- a/internal/configuration/sources/env/helpers.go
+++ b/internal/configuration/sources/env/helpers.go
@@ -29,8 +29,8 @@ func envToFloat64(envKey string) (f float64, err error) {
 	return strconv.ParseFloat(s, bits)
 }
 
-func envToStringPtr(envKey string) (stringPtr *string) {
-	s := env.Get(envKey)
+func envToStringPtr(envKey string, options ...env.Option) (stringPtr *string) {
+	s := env.Get(envKey, options...)
 	if s == "" {
 		return nil
 	}
diff --git a/internal/configuration/sources/env/httproxy.go b/internal/configuration/sources/env/httproxy.go
index bb6fa8fd..e4482fd3 100644
--- a/internal/configuration/sources/env/httproxy.go
+++ b/internal/configuration/sources/env/httproxy.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gosettings/sources/env"
 	"github.com/qdm12/govalid/binary"
 )
 
@@ -31,7 +32,8 @@ func (s *Source) readHTTPProxy() (httpProxy settings.HTTPProxy, err error) {
 }
 
 func (s *Source) readHTTProxyUser() (user *string) {
-	_, value := s.getEnvWithRetro("HTTPPROXY_USER", "PROXY_USER", "TINYPROXY_USER")
+	_, value := s.getEnvWithRetro("HTTPPROXY_USER",
+		[]string{"PROXY_USER", "TINYPROXY_USER"}, env.ForceLowercase(false))
 	if value != "" {
 		return &value
 	}
@@ -39,7 +41,8 @@ func (s *Source) readHTTProxyUser() (user *string) {
 }
 
 func (s *Source) readHTTProxyPassword() (user *string) {
-	_, value := s.getEnvWithRetro("HTTPPROXY_PASSWORD", "PROXY_PASSWORD", "TINYPROXY_PASSWORD")
+	_, value := s.getEnvWithRetro("HTTPPROXY_PASSWORD",
+		[]string{"PROXY_PASSWORD", "TINYPROXY_PASSWORD"}, env.ForceLowercase(false))
 	if value != "" {
 		return &value
 	}
@@ -47,7 +50,8 @@ func (s *Source) readHTTProxyPassword() (user *string) {
 }
 
 func (s *Source) readHTTProxyListeningAddress() (listeningAddress string) {
-	key, value := s.getEnvWithRetro("HTTPPROXY_LISTENING_ADDRESS", "PROXY_PORT", "TINYPROXY_PORT", "HTTPPROXY_PORT")
+	key, value := s.getEnvWithRetro("HTTPPROXY_LISTENING_ADDRESS",
+		[]string{"PROXY_PORT", "TINYPROXY_PORT", "HTTPPROXY_PORT"})
 	if key == "HTTPPROXY_LISTENING_ADDRESS" {
 		return value
 	}
@@ -55,7 +59,8 @@ func (s *Source) readHTTProxyListeningAddress() (listeningAddress string) {
 }
 
 func (s *Source) readHTTProxyEnabled() (enabled *bool, err error) {
-	key, value := s.getEnvWithRetro("HTTPPROXY", "PROXY", "TINYPROXY")
+	key, value := s.getEnvWithRetro("HTTPPROXY",
+		[]string{"PROXY", "TINYPROXY"})
 	enabled, err = binary.Validate(value)
 	if err != nil {
 		return nil, fmt.Errorf("environment variable %s: %w", key, err)
@@ -65,7 +70,8 @@ func (s *Source) readHTTProxyEnabled() (enabled *bool, err error) {
 }
 
 func (s *Source) readHTTProxyLog() (enabled *bool, err error) {
-	key, value := s.getEnvWithRetro("HTTPPROXY_LOG", "PROXY_LOG_LEVEL", "TINYPROXY_LOG")
+	key, value := s.getEnvWithRetro("HTTPPROXY_LOG",
+		[]string{"PROXY_LOG_LEVEL", "TINYPROXY_LOG"})
 
 	var binaryOptions []binary.Option
 	if key != "HTTPROXY_LOG" {
diff --git a/internal/configuration/sources/env/openvpn.go b/internal/configuration/sources/env/openvpn.go
index 99d4262d..724678f9 100644
--- a/internal/configuration/sources/env/openvpn.go
+++ b/internal/configuration/sources/env/openvpn.go
@@ -24,7 +24,7 @@ func (s *Source) readOpenVPN() (
 		openVPN.ConfFile = &confFile
 	}
 
-	ciphersKey, _ := s.getEnvWithRetro("OPENVPN_CIPHERS", "OPENVPN_CIPHER")
+	ciphersKey, _ := s.getEnvWithRetro("OPENVPN_CIPHERS", []string{"OPENVPN_CIPHER"})
 	openVPN.Ciphers = envToCSV(ciphersKey)
 
 	auth := env.Get("OPENVPN_AUTH")
@@ -32,9 +32,9 @@ func (s *Source) readOpenVPN() (
 		openVPN.Auth = &auth
 	}
 
-	openVPN.Cert = envToStringPtr("OPENVPN_CERT")
-	openVPN.Key = envToStringPtr("OPENVPN_KEY")
-	openVPN.EncryptedKey = envToStringPtr("OPENVPN_ENCRYPTED_KEY")
+	openVPN.Cert = envToStringPtr("OPENVPN_CERT", env.ForceLowercase(false))
+	openVPN.Key = envToStringPtr("OPENVPN_KEY", env.ForceLowercase(false))
+	openVPN.EncryptedKey = envToStringPtr("OPENVPN_ENCRYPTED_KEY", env.ForceLowercase(false))
 
 	openVPN.KeyPassphrase = s.readOpenVPNKeyPassphrase()
 
@@ -45,7 +45,8 @@ func (s *Source) readOpenVPN() (
 		return openVPN, fmt.Errorf("environment variable OPENVPN_MSSFIX: %w", err)
 	}
 
-	_, openVPN.Interface = s.getEnvWithRetro("VPN_INTERFACE", "OPENVPN_INTERFACE")
+	_, openVPN.Interface = s.getEnvWithRetro("VPN_INTERFACE",
+		[]string{"OPENVPN_INTERFACE"}, env.ForceLowercase(false))
 
 	openVPN.ProcessUser, err = s.readOpenVPNProcessUser()
 	if err != nil {
@@ -57,7 +58,7 @@ func (s *Source) readOpenVPN() (
 		return openVPN, fmt.Errorf("environment variable OPENVPN_VERBOSITY: %w", err)
 	}
 
-	flagsStr := env.Get("OPENVPN_FLAGS")
+	flagsStr := env.Get("OPENVPN_FLAGS", env.ForceLowercase(false))
 	if flagsStr != "" {
 		openVPN.Flags = strings.Fields(flagsStr)
 	}
@@ -67,7 +68,8 @@ func (s *Source) readOpenVPN() (
 
 func (s *Source) readOpenVPNUser() (user *string) {
 	user = new(string)
-	_, *user = s.getEnvWithRetro("OPENVPN_USER", "USER")
+	_, *user = s.getEnvWithRetro("OPENVPN_USER",
+		[]string{"USER"}, env.ForceLowercase(false))
 	if *user == "" {
 		return nil
 	}
@@ -79,7 +81,8 @@ func (s *Source) readOpenVPNUser() (user *string) {
 
 func (s *Source) readOpenVPNPassword() (password *string) {
 	password = new(string)
-	_, *password = s.getEnvWithRetro("OPENVPN_PASSWORD", "PASSWORD")
+	_, *password = s.getEnvWithRetro("OPENVPN_PASSWORD",
+		[]string{"PASSWORD"}, env.ForceLowercase(false))
 	if *password == "" {
 		return nil
 	}
@@ -89,7 +92,7 @@ func (s *Source) readOpenVPNPassword() (password *string) {
 
 func (s *Source) readOpenVPNKeyPassphrase() (passphrase *string) {
 	passphrase = new(string)
-	*passphrase = env.Get("OPENVPN_KEY_PASSPHRASE")
+	*passphrase = env.Get("OPENVPN_KEY_PASSPHRASE", env.ForceLowercase(false))
 	if *passphrase == "" {
 		return nil
 	}
@@ -99,7 +102,7 @@ func (s *Source) readOpenVPNKeyPassphrase() (passphrase *string) {
 func (s *Source) readPIAEncryptionPreset() (presetPtr *string) {
 	_, preset := s.getEnvWithRetro(
 		"PRIVATE_INTERNET_ACCESS_OPENVPN_ENCRYPTION_PRESET",
-		"PIA_ENCRYPTION", "ENCRYPTION")
+		[]string{"PIA_ENCRYPTION", "ENCRYPTION"})
 	if preset != "" {
 		return &preset
 	}
@@ -107,7 +110,8 @@ func (s *Source) readPIAEncryptionPreset() (presetPtr *string) {
 }
 
 func (s *Source) readOpenVPNProcessUser() (processUser string, err error) {
-	key, value := s.getEnvWithRetro("OPENVPN_PROCESS_USER", "OPENVPN_ROOT")
+	key, value := s.getEnvWithRetro("OPENVPN_PROCESS_USER",
+		[]string{"OPENVPN_ROOT"})
 	if key == "OPENVPN_PROCESS_USER" {
 		return value, nil
 	}
diff --git a/internal/configuration/sources/env/openvpnselection.go b/internal/configuration/sources/env/openvpnselection.go
index e606ec6a..5a6e84e7 100644
--- a/internal/configuration/sources/env/openvpnselection.go
+++ b/internal/configuration/sources/env/openvpnselection.go
@@ -13,7 +13,7 @@ import (
 
 func (s *Source) readOpenVPNSelection() (
 	selection settings.OpenVPNSelection, err error) {
-	confFile := env.Get("OPENVPN_CUSTOM_CONFIG")
+	confFile := env.Get("OPENVPN_CUSTOM_CONFIG", env.ForceLowercase(false))
 	if confFile != "" {
 		selection.ConfFile = &confFile
 	}
@@ -36,7 +36,7 @@ func (s *Source) readOpenVPNSelection() (
 var ErrOpenVPNProtocolNotValid = errors.New("OpenVPN protocol is not valid")
 
 func (s *Source) readOpenVPNProtocol() (tcp *bool, err error) {
-	envKey, protocol := s.getEnvWithRetro("OPENVPN_PROTOCOL", "PROTOCOL")
+	envKey, protocol := s.getEnvWithRetro("OPENVPN_PROTOCOL", []string{"PROTOCOL"})
 
 	switch strings.ToLower(protocol) {
 	case "":
@@ -52,7 +52,7 @@ func (s *Source) readOpenVPNProtocol() (tcp *bool, err error) {
 }
 
 func (s *Source) readOpenVPNCustomPort() (customPort *uint16, err error) {
-	key, value := s.getEnvWithRetro("VPN_ENDPOINT_PORT", "PORT", "OPENVPN_PORT")
+	key, value := s.getEnvWithRetro("VPN_ENDPOINT_PORT", []string{"PORT", "OPENVPN_PORT"})
 	if value == "" {
 		return nil, nil //nolint:nilnil
 	}
diff --git a/internal/configuration/sources/env/portforward.go b/internal/configuration/sources/env/portforward.go
index 203e156d..b81d611e 100644
--- a/internal/configuration/sources/env/portforward.go
+++ b/internal/configuration/sources/env/portforward.go
@@ -4,23 +4,26 @@ import (
 	"fmt"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gosettings/sources/env"
 )
 
 func (s *Source) readPortForward() (
 	portForwarding settings.PortForwarding, err error) {
-	key, _ := s.getEnvWithRetro(
-		"VPN_PORT_FORWARDING",
-		"PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING",
-		"PORT_FORWARDING")
+	key, _ := s.getEnvWithRetro("VPN_PORT_FORWARDING",
+		[]string{
+			"PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING",
+			"PORT_FORWARDING",
+		})
 	portForwarding.Enabled, err = envToBoolPtr(key)
 	if err != nil {
 		return portForwarding, fmt.Errorf("environment variable %s: %w", key, err)
 	}
 
-	_, value := s.getEnvWithRetro(
-		"VPN_PORT_FORWARDING_STATUS_FILE",
-		"PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING_STATUS_FILE",
-		"PORT_FORWARDING_STATUS_FILE")
+	_, value := s.getEnvWithRetro("VPN_PORT_FORWARDING_STATUS_FILE",
+		[]string{
+			"PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING_STATUS_FILE",
+			"PORT_FORWARDING_STATUS_FILE",
+		}, env.ForceLowercase(false))
 	if value != "" {
 		portForwarding.Filepath = stringPtr(value)
 	}
diff --git a/internal/configuration/sources/env/provider.go b/internal/configuration/sources/env/provider.go
index 7ab44b16..bdf22c99 100644
--- a/internal/configuration/sources/env/provider.go
+++ b/internal/configuration/sources/env/provider.go
@@ -31,7 +31,7 @@ func (s *Source) readProvider(vpnType string) (provider settings.Provider, err e
 }
 
 func (s *Source) readVPNServiceProvider(vpnType string) (vpnProviderPtr *string) {
-	_, value := s.getEnvWithRetro("VPN_SERVICE_PROVIDER", "VPNSP")
+	_, value := s.getEnvWithRetro("VPN_SERVICE_PROVIDER", []string{"VPNSP"})
 	if value == "" {
 		if vpnType != vpn.Wireguard && env.Get("OPENVPN_CUSTOM_CONFIG") != "" {
 			// retro compatibility
diff --git a/internal/configuration/sources/env/publicip.go b/internal/configuration/sources/env/publicip.go
index a9f93d48..4a61e697 100644
--- a/internal/configuration/sources/env/publicip.go
+++ b/internal/configuration/sources/env/publicip.go
@@ -35,7 +35,8 @@ func readPublicIPPeriod() (period *time.Duration, err error) {
 }
 
 func (s *Source) readPublicIPFilepath() (filepath *string) {
-	_, value := s.getEnvWithRetro("PUBLICIP_FILE", "IP_STATUS_FILE")
+	_, value := s.getEnvWithRetro("PUBLICIP_FILE",
+		[]string{"IP_STATUS_FILE"}, env.ForceLowercase(false))
 	if value != "" {
 		return &value
 	}
diff --git a/internal/configuration/sources/env/reader.go b/internal/configuration/sources/env/reader.go
index 0fde429e..6a72e4b6 100644
--- a/internal/configuration/sources/env/reader.go
+++ b/internal/configuration/sources/env/reader.go
@@ -103,16 +103,16 @@ func (s *Source) onRetroActive(oldKey, newKey string) {
 // Note retroKeys should be in order from oldest to most
 // recent retro-compatibility key.
 func (s *Source) getEnvWithRetro(currentKey string,
-	retroKeys ...string) (key, value string) {
+	retroKeys []string, options ...env.Option) (key, value string) {
 	// We check retro-compatibility keys first since
 	// the current key might be set in the Dockerfile.
 	for _, key = range retroKeys {
-		value = env.Get(key)
+		value = env.Get(key, options...)
 		if value != "" {
 			s.onRetroActive(key, currentKey)
 			return key, value
 		}
 	}
 
-	return currentKey, env.Get(currentKey)
+	return currentKey, env.Get(currentKey, options...)
 }
diff --git a/internal/configuration/sources/env/server.go b/internal/configuration/sources/env/server.go
index d3ef2188..c27d64d2 100644
--- a/internal/configuration/sources/env/server.go
+++ b/internal/configuration/sources/env/server.go
@@ -29,7 +29,8 @@ func readControlServerLog() (enabled *bool, err error) {
 }
 
 func (s *Source) readControlServerAddress() (address *string) {
-	key, value := s.getEnvWithRetro("HTTP_CONTROL_SERVER_ADDRESS", "HTTP_CONTROL_SERVER_PORT")
+	key, value := s.getEnvWithRetro("HTTP_CONTROL_SERVER_ADDRESS",
+		[]string{"CONTROL_SERVER_ADDRESS"})
 	if value == "" {
 		return nil
 	}
diff --git a/internal/configuration/sources/env/serverselection.go b/internal/configuration/sources/env/serverselection.go
index 680c4cb8..48c788e3 100644
--- a/internal/configuration/sources/env/serverselection.go
+++ b/internal/configuration/sources/env/serverselection.go
@@ -25,7 +25,7 @@ func (s *Source) readServerSelection(vpnProvider, vpnType string) (
 		return ss, err
 	}
 
-	countriesKey, _ := s.getEnvWithRetro("SERVER_COUNTRIES", "COUNTRY")
+	countriesKey, _ := s.getEnvWithRetro("SERVER_COUNTRIES", []string{"COUNTRY"})
 	ss.Countries = envToCSV(countriesKey)
 	if vpnProvider == providers.Cyberghost && len(ss.Countries) == 0 {
 		// Retro-compatibility for Cyberghost using the REGION variable
@@ -35,18 +35,18 @@ func (s *Source) readServerSelection(vpnProvider, vpnType string) (
 		}
 	}
 
-	regionsKey, _ := s.getEnvWithRetro("SERVER_REGIONS", "REGION")
+	regionsKey, _ := s.getEnvWithRetro("SERVER_REGIONS", []string{"REGION"})
 	ss.Regions = envToCSV(regionsKey)
 
-	citiesKey, _ := s.getEnvWithRetro("SERVER_CITIES", "CITY")
+	citiesKey, _ := s.getEnvWithRetro("SERVER_CITIES", []string{"CITY"})
 	ss.Cities = envToCSV(citiesKey)
 
 	ss.ISPs = envToCSV("ISP")
 
-	hostnamesKey, _ := s.getEnvWithRetro("SERVER_HOSTNAMES", "SERVER_HOSTNAME")
+	hostnamesKey, _ := s.getEnvWithRetro("SERVER_HOSTNAMES", []string{"SERVER_HOSTNAME"})
 	ss.Hostnames = envToCSV(hostnamesKey)
 
-	serverNamesKey, _ := s.getEnvWithRetro("SERVER_NAMES", "SERVER_NAME")
+	serverNamesKey, _ := s.getEnvWithRetro("SERVER_NAMES", []string{"SERVER_NAME"})
 	ss.Names = envToCSV(serverNamesKey)
 
 	if csv := env.Get("SERVER_NUMBER"); csv != "" {
@@ -115,7 +115,7 @@ var (
 )
 
 func (s *Source) readOpenVPNTargetIP() (ip netip.Addr, err error) {
-	envKey, value := s.getEnvWithRetro("VPN_ENDPOINT_IP", "OPENVPN_TARGET_IP")
+	envKey, value := s.getEnvWithRetro("VPN_ENDPOINT_IP", []string{"OPENVPN_TARGET_IP"})
 	if value == "" {
 		return ip, nil
 	}
@@ -129,7 +129,7 @@ func (s *Source) readOpenVPNTargetIP() (ip netip.Addr, err error) {
 }
 
 func (s *Source) readOwnedOnly() (ownedOnly *bool, err error) {
-	envKey, _ := s.getEnvWithRetro("OWNED_ONLY", "OWNED")
+	envKey, _ := s.getEnvWithRetro("OWNED_ONLY", []string{"OWNED"})
 	ownedOnly, err = envToBoolPtr(envKey)
 	if err != nil {
 		return nil, fmt.Errorf("environment variable %s: %w", envKey, err)
diff --git a/internal/configuration/sources/env/shadowsocks.go b/internal/configuration/sources/env/shadowsocks.go
index a9bace58..713191fa 100644
--- a/internal/configuration/sources/env/shadowsocks.go
+++ b/internal/configuration/sources/env/shadowsocks.go
@@ -5,6 +5,7 @@ import (
 	"strings"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gosettings/sources/env"
 )
 
 func (s *Source) readShadowsocks() (shadowsocks settings.Shadowsocks, err error) {
@@ -19,13 +20,14 @@ func (s *Source) readShadowsocks() (shadowsocks settings.Shadowsocks, err error)
 		return shadowsocks, fmt.Errorf("environment variable SHADOWSOCKS_LOG: %w", err)
 	}
 	shadowsocks.CipherName = s.readShadowsocksCipher()
-	shadowsocks.Password = envToStringPtr("SHADOWSOCKS_PASSWORD")
+	shadowsocks.Password = envToStringPtr("SHADOWSOCKS_PASSWORD", env.ForceLowercase(false))
 
 	return shadowsocks, nil
 }
 
 func (s *Source) readShadowsocksAddress() (address string) {
-	key, value := s.getEnvWithRetro("SHADOWSOCKS_LISTENING_ADDRESS", "SHADOWSOCKS_PORT")
+	key, value := s.getEnvWithRetro("SHADOWSOCKS_LISTENING_ADDRESS",
+		[]string{"SHADOWSOCKS_PORT"})
 	if value == "" {
 		return ""
 	}
@@ -39,6 +41,7 @@ func (s *Source) readShadowsocksAddress() (address string) {
 }
 
 func (s *Source) readShadowsocksCipher() (cipher string) {
-	_, cipher = s.getEnvWithRetro("SHADOWSOCKS_CIPHER", "SHADOWSOCKS_METHOD")
+	_, cipher = s.getEnvWithRetro("SHADOWSOCKS_CIPHER",
+		[]string{"SHADOWSOCKS_METHOD"})
 	return strings.ToLower(cipher)
 }
diff --git a/internal/configuration/sources/env/system.go b/internal/configuration/sources/env/system.go
index b4adf3d5..0fc05d23 100644
--- a/internal/configuration/sources/env/system.go
+++ b/internal/configuration/sources/env/system.go
@@ -35,7 +35,7 @@ var ErrSystemIDNotValid = errors.New("system ID is not valid")
 
 func (s *Source) readID(key, retroKey string) (
 	id *uint32, err error) {
-	idEnvKey, idString := s.getEnvWithRetro(key, retroKey)
+	idEnvKey, idString := s.getEnvWithRetro(key, []string{retroKey})
 	if idString == "" {
 		return nil, nil //nolint:nilnil
 	}
diff --git a/internal/configuration/sources/env/wireguard.go b/internal/configuration/sources/env/wireguard.go
index 6bfe821c..7592dd23 100644
--- a/internal/configuration/sources/env/wireguard.go
+++ b/internal/configuration/sources/env/wireguard.go
@@ -13,9 +13,10 @@ func (s *Source) readWireguard() (wireguard settings.Wireguard, err error) {
 	defer func() {
 		err = unsetEnvKeys([]string{"WIREGUARD_PRIVATE_KEY", "WIREGUARD_PRESHARED_KEY"}, err)
 	}()
-	wireguard.PrivateKey = envToStringPtr("WIREGUARD_PRIVATE_KEY")
-	wireguard.PreSharedKey = envToStringPtr("WIREGUARD_PRESHARED_KEY")
-	_, wireguard.Interface = s.getEnvWithRetro("VPN_INTERFACE", "WIREGUARD_INTERFACE")
+	wireguard.PrivateKey = envToStringPtr("WIREGUARD_PRIVATE_KEY", env.ForceLowercase(false))
+	wireguard.PreSharedKey = envToStringPtr("WIREGUARD_PRESHARED_KEY", env.ForceLowercase(false))
+	_, wireguard.Interface = s.getEnvWithRetro("VPN_INTERFACE",
+		[]string{"WIREGUARD_INTERFACE"}, env.ForceLowercase(false))
 	wireguard.Implementation = env.Get("WIREGUARD_IMPLEMENTATION")
 	wireguard.Addresses, err = s.readWireguardAddresses()
 	if err != nil {
@@ -31,7 +32,8 @@ func (s *Source) readWireguard() (wireguard settings.Wireguard, err error) {
 }
 
 func (s *Source) readWireguardAddresses() (addresses []netip.Prefix, err error) {
-	key, addressesCSV := s.getEnvWithRetro("WIREGUARD_ADDRESSES", "WIREGUARD_ADDRESS")
+	key, addressesCSV := s.getEnvWithRetro("WIREGUARD_ADDRESSES",
+		[]string{"WIREGUARD_ADDRESS"})
 	if addressesCSV == "" {
 		return nil, nil
 	}
diff --git a/internal/configuration/sources/env/wireguardselection.go b/internal/configuration/sources/env/wireguardselection.go
index 952cc854..a7fd1520 100644
--- a/internal/configuration/sources/env/wireguardselection.go
+++ b/internal/configuration/sources/env/wireguardselection.go
@@ -21,13 +21,13 @@ func (s *Source) readWireguardSelection() (
 		return selection, err
 	}
 
-	selection.PublicKey = env.Get("WIREGUARD_PUBLIC_KEY")
+	selection.PublicKey = env.Get("WIREGUARD_PUBLIC_KEY", env.ForceLowercase(false))
 
 	return selection, nil
 }
 
 func (s *Source) readWireguardEndpointIP() (endpointIP netip.Addr, err error) {
-	key, value := s.getEnvWithRetro("VPN_ENDPOINT_IP", "WIREGUARD_ENDPOINT_IP")
+	key, value := s.getEnvWithRetro("VPN_ENDPOINT_IP", []string{"WIREGUARD_ENDPOINT_IP"})
 	if value == "" {
 		return endpointIP, nil
 	}
@@ -41,7 +41,7 @@ func (s *Source) readWireguardEndpointIP() (endpointIP netip.Addr, err error) {
 }
 
 func (s *Source) readWireguardCustomPort() (customPort *uint16, err error) {
-	key, value := s.getEnvWithRetro("VPN_ENDPOINT_PORT", "WIREGUARD_ENDPOINT_PORT")
+	key, value := s.getEnvWithRetro("VPN_ENDPOINT_PORT", []string{"WIREGUARD_ENDPOINT_PORT"})
 	if value == "" {
 		return nil, nil //nolint:nilnil
 	}