Support TLS configuration as raw bytes

This change is intended to allow users to configure TLS settings in the
form of raw byte slices. This is particularly useful for situations
where the FIX application is running in a cloud environment (e.g. k8s)
and session configuration is loaded from a database (rather than a
static file). In this scenario it is much more convenient to be able to
load TLS key pairs from the DB in the form of byte slices, than to have
to ensure files with the correct names exist on some persistent volume
such that the FIX app can load them from disk correctly.

To support this we changed the basic type stored within SessionSettings
to be a byte slice which means we are able to still support the existing
settings model, but also handle raw byte slices we can use for TLS
setup. The existing API exposed by SessionSettings remains unchanged
meaning users should not have to update their codee, but we have added a
new `SetRaw` and `RawSetting` accessors to directly read/write byte
slice values.

Author: smulube

config/configuration.go

@@ -739,6 +739,47 @@ const (
 	//  - A filepath to a file with read access.
 	SocketCAFile string = "SocketCAFile"
 
+	// SocketPrivateKeyBytes is an optional value containing raw bytes of a PEM
+	// encoded private key to use for secure TLS communications.
+	// Must be used with SocketCertificateBytes.
+	// Must contain PEM encoded data.
+	//
+	// Required: No
+	//
+	// Default: N/A
+	//
+	// Valid Values:
+	//  - Raw bytes containing a valid PEM encoded private key.
+	SocketPrivateKeyBytes string = "SocketPrivateKeyBytes"
+
+	// SocketCertificateBytes is an optional value containing raw bytes of a PEM
+	// encoded certificate to use for secure TLS communications.
+	// Must be used with SocketPrivateKeyBytes.
+	// Must contain PEM encoded data.
+	//
+	// Required: No
+	//
+	// Default: N/A
+	//
+	// Valid Values:
+	//  - Raw bytes containing a valid PEM encoded certificate.
+	SocketCertificateBytes string = "SocketCertificateBytes"
+
+	// SocketCABytes is an optional value containing raw bytes of a PEM encoded
+	// root CA to use for secure TLS communications. For acceptors, client
+	// certificates will be verified against this CA. For initiators, clients
+	// will use the CA to verify the server certificate. If not configured,
+	// initiators will verify the server certificates using the host's root CA
+	// set.
+	//
+	// Required: No
+	//
+	// Default: N/A
+	//
+	// Valid Values:
+	//  - Raw bytes containing a valid PEM encoded CA.
+	SocketCABytes string = "SocketCABytes"
+
 	// SocketInsecureSkipVerify controls whether a client verifies the server's certificate chain and host name.
 	// If SocketInsecureSkipVerify is set to Y, crypto/tls accepts any certificate presented by the server and any host name in that certificate.
 	// In this mode, TLS is susceptible to machine-in-the-middle attacks unless custom verification is used.

session_factory.go

@@ -284,7 +284,7 @@ func (f sessionFactory) newSession(
 				for _, dayStr := range dayStrs {
 					day, ok := dayLookup[dayStr]
 					if !ok {
-						err = IncorrectFormatForSetting{Setting: config.Weekdays, Value: weekdaysStr}
+						err = IncorrectFormatForSetting{Setting: config.Weekdays, Value: []byte(weekdaysStr)}
 						return
 					}
 					weekdays = append(weekdays, day)
@@ -315,7 +315,7 @@ func (f sessionFactory) newSession(
 			parseDay := func(setting, dayStr string) (day time.Weekday, err error) {
 				day, ok := dayLookup[dayStr]
 				if !ok {
-					return day, IncorrectFormatForSetting{Setting: setting, Value: dayStr}
+					return day, IncorrectFormatForSetting{Setting: setting, Value: []byte(dayStr)}
 				}
 				return
 			}
@@ -355,7 +355,7 @@ func (f sessionFactory) newSession(
 			s.timestampPrecision = Nanos
 
 		default:
-			err = IncorrectFormatForSetting{Setting: config.TimeStampPrecision, Value: precisionStr}
+			err = IncorrectFormatForSetting{Setting: config.TimeStampPrecision, Value: []byte(precisionStr)}
 			return
 		}
 	}

session_settings.go

@@ -23,7 +23,7 @@ import (
 
 // SessionSettings maps session settings to values with typed accessors.
 type SessionSettings struct {
-	settings map[string]string
+	settings map[string][]byte
 }
 
 // ConditionallyRequiredSetting indicates a missing setting.
@@ -37,8 +37,9 @@ func (e ConditionallyRequiredSetting) Error() string {
 
 // IncorrectFormatForSetting indicates a setting that is incorrectly formatted.
 type IncorrectFormatForSetting struct {
-	Setting, Value string
-	Err            error
+	Setting string
+	Value   []byte
+	Err     error
 }
 
 func (e IncorrectFormatForSetting) Error() string {
@@ -47,7 +48,7 @@ func (e IncorrectFormatForSetting) Error() string {
 
 // Init initializes or resets SessionSettings.
 func (s *SessionSettings) Init() {
-	s.settings = make(map[string]string)
+	s.settings = make(map[string][]byte)
 }
 
 // NewSessionSettings returns a newly initialized SessionSettings instance.
@@ -58,8 +59,8 @@ func NewSessionSettings() *SessionSettings {
 	return s
 }
 
-// Set assigns a value to a setting on SessionSettings.
-func (s *SessionSettings) Set(setting string, val string) {
+// SetRaw assigns a value to a setting on SessionSettings.
+func (s *SessionSettings) SetRaw(setting string, val []byte) {
 	// Lazy init.
 	if s.settings == nil {
 		s.Init()
@@ -68,69 +69,87 @@ func (s *SessionSettings) Set(setting string, val string) {
 	s.settings[setting] = val
 }
 
+// Set assigns a string value to a setting on SessionSettings.
+func (s *SessionSettings) Set(setting string, val string) {
+	// Lazy init
+	if s.settings == nil {
+		s.Init()
+	}
+
+	s.settings[setting] = []byte(val)
+}
+
 // HasSetting returns true if a setting is set, false if not.
 func (s *SessionSettings) HasSetting(setting string) bool {
 	_, ok := s.settings[setting]
 	return ok
 }
 
-// Setting is a settings string accessor. Returns an error if the setting is missing.
-func (s *SessionSettings) Setting(setting string) (string, error) {
+// RawSetting is a settings accessor that returns the raw byte slice value of
+// the setting. Returns an error if the setting is missing.
+func (s *SessionSettings) RawSetting(setting string) ([]byte, error) {
 	val, ok := s.settings[setting]
 	if !ok {
-		return val, ConditionallyRequiredSetting{setting}
+		return nil, ConditionallyRequiredSetting{Setting: setting}
 	}
 
 	return val, nil
 }
 
-// IntSetting returns the requested setting parsed as an int.  Returns an errror if the setting is not set or cannot be parsed as an int.
-func (s *SessionSettings) IntSetting(setting string) (val int, err error) {
-	stringVal, err := s.Setting(setting)
+// Setting is a settings string accessor. Returns an error if the setting is missing.
+func (s *SessionSettings) Setting(setting string) (string, error) {
+	val, err := s.RawSetting(setting)
+	if err != nil {
+		return "", err
+	}
 
+	return string(val), nil
+}
+
+// IntSetting returns the requested setting parsed as an int.  Returns an errror if the setting is not set or cannot be parsed as an int.
+func (s *SessionSettings) IntSetting(setting string) (int, error) {
+	rawVal, err := s.RawSetting(setting)
 	if err != nil {
-		return
+		return 0, err
 	}
 
-	if val, err = strconv.Atoi(stringVal); err != nil {
-		return val, IncorrectFormatForSetting{Setting: setting, Value: stringVal, Err: err}
+	if val, err := strconv.Atoi(string(rawVal)); err == nil {
+		return val, nil
 	}
 
-	return
+	return 0, IncorrectFormatForSetting{Setting: setting, Value: rawVal, Err: err}
 }
 
 // DurationSetting returns the requested setting parsed as a time.Duration.
 // Returns an error if the setting is not set or cannot be parsed as a time.Duration.
-func (s *SessionSettings) DurationSetting(setting string) (val time.Duration, err error) {
-	stringVal, err := s.Setting(setting)
-
+func (s *SessionSettings) DurationSetting(setting string) (time.Duration, error) {
+	rawVal, err := s.RawSetting(setting)
 	if err != nil {
-		return
+		return 0, err
 	}
 
-	if val, err = time.ParseDuration(stringVal); err != nil {
-		return val, IncorrectFormatForSetting{Setting: setting, Value: stringVal, Err: err}
+	if val, err := time.ParseDuration(string(rawVal)); err == nil {
+		return val, nil
 	}
 
-	return
+	return 0, IncorrectFormatForSetting{Setting: setting, Value: rawVal, Err: err}
 }
 
 // BoolSetting returns the requested setting parsed as a boolean.  Returns an error if the setting is not set or cannot be parsed as a bool.
 func (s SessionSettings) BoolSetting(setting string) (bool, error) {
-	stringVal, err := s.Setting(setting)
-
+	rawVal, err := s.RawSetting(setting)
 	if err != nil {
 		return false, err
 	}
 
-	switch stringVal {
+	switch string(rawVal) {
 	case "Y", "y":
 		return true, nil
 	case "N", "n":
 		return false, nil
 	}
 
-	return false, IncorrectFormatForSetting{Setting: setting, Value: stringVal}
+	return false, IncorrectFormatForSetting{Setting: setting, Value: rawVal}
 }
 
 func (s *SessionSettings) overlay(overlay *SessionSettings) {

session_settings_test.go

@@ -16,7 +16,9 @@
 package quickfix
 
 import (
+	"bytes"
 	"testing"
+	"time"
 
 	"github.com/quickfixgo/quickfix/config"
 )
@@ -55,10 +57,15 @@ func TestSessionSettings_IntSettings(t *testing.T) {
 	}
 
 	s.Set(config.SocketAcceptPort, "notanint")
-	if _, err := s.IntSetting(config.SocketAcceptPort); err == nil {
+	_, err := s.IntSetting(config.SocketAcceptPort)
+	if err == nil {
 		t.Error("Expected error for unparsable value")
 	}
 
+	if err.Error() != `"notanint" is invalid for SocketAcceptPort` {
+		t.Errorf("Expected %s, got %s", `"notanint" is invalid for SocketAcceptPort`, err)
+	}
+
 	s.Set(config.SocketAcceptPort, "1005")
 	val, err := s.IntSetting(config.SocketAcceptPort)
 	if err != nil {
@@ -77,10 +84,15 @@ func TestSessionSettings_BoolSettings(t *testing.T) {
 	}
 
 	s.Set(config.ResetOnLogon, "notabool")
-	if _, err := s.BoolSetting(config.ResetOnLogon); err == nil {
+	_, err := s.BoolSetting(config.ResetOnLogon)
+	if err == nil {
 		t.Error("Expected error for unparsable value")
 	}
 
+	if err.Error() != `"notabool" is invalid for ResetOnLogon` {
+		t.Errorf("Expected %s, got %s", `"notabool" is invalid for ResetOnLogon`, err)
+	}
+
 	var boolTests = []struct {
 		input    string
 		expected bool
@@ -105,6 +117,55 @@ func TestSessionSettings_BoolSettings(t *testing.T) {
 	}
 }
 
+func TestSessionSettings_DurationSettings(t *testing.T) {
+	s := NewSessionSettings()
+	if _, err := s.BoolSetting(config.ReconnectInterval); err == nil {
+		t.Error("Expected error for unknown setting")
+	}
+
+	s.Set(config.ReconnectInterval, "not duration")
+
+	_, err := s.DurationSetting(config.ReconnectInterval)
+	if err == nil {
+		t.Error("Expected error for unparsable value")
+	}
+
+	if err.Error() != `"not duration" is invalid for ReconnectInterval` {
+		t.Errorf("Expected %s, got %s", `"not duration" is invalid for ReconnectInterval`, err)
+	}
+
+	s.Set(config.ReconnectInterval, "10s")
+
+	got, err := s.DurationSetting(config.ReconnectInterval)
+	if err != nil {
+		t.Error("Unexpected err", err)
+	}
+
+	expected, _ := time.ParseDuration("10s")
+
+	if got != expected {
+		t.Errorf("Expected %v, got %v", expected, got)
+	}
+}
+
+func TestSessionSettings_ByteSettings(t *testing.T) {
+	s := NewSessionSettings()
+	if _, err := s.RawSetting(config.SocketPrivateKeyBytes); err == nil {
+		t.Error("Expected error for unknown setting")
+	}
+
+	s.SetRaw(config.SocketPrivateKeyBytes, []byte("pembytes"))
+
+	got, err := s.RawSetting(config.SocketPrivateKeyBytes)
+	if err != nil {
+		t.Error("Unexpected err", err)
+	}
+
+	if !bytes.Equal([]byte("pembytes"), got) {
+		t.Errorf("Expected %v, got %v", []byte("pembytes"), got)
+	}
+}
+
 func TestSessionSettings_Clone(t *testing.T) {
 	s := NewSessionSettings()