Create methods to clone a tls.Config for older versions of go

We opted to copy the struct manually in order avoid copying
internal objects (ie. the sync.Mutex and sync.Once in go1.7)

Signed-off-by: Dave Protasowski <[email protected]>

Author: Rebecca Chin

AUTHORS

@@ -61,5 +61,5 @@ Zhenye Xie <xiezhenye at gmail.com>
 
 Barracuda Networks, Inc.
 Google Inc.
-Stripe Inc.
 Pivotal Inc.
+Stripe Inc.

dsn.go

@@ -511,7 +511,7 @@ func parseDSNParams(cfg *Config, params string) (err error) {
 				}
 
 				if tlsConfig, ok := tlsConfigRegister[name]; ok {
-					tlsConfig = tlsConfig.Clone()
+					tlsConfig = cloneTLSConfig(tlsConfig)
 
 					if len(tlsConfig.ServerName) == 0 && !tlsConfig.InsecureSkipVerify {
 						host, _, err := net.SplitHostPort(cfg.Addr)

tls_config_clone_go12.go

@@ -0,0 +1,27 @@
+// +build go1.2
+// +build !go1.3
+
+package mysql
+
+import "crypto/tls"
+
+func cloneTLSConfig(c *tls.Config) *tls.Config {
+	return &tls.Config{
+		Rand:                     c.Rand,
+		Time:                     c.Time,
+		Certificates:             c.Certificates,
+		NameToCertificate:        c.NameToCertificate,
+		RootCAs:                  c.RootCAs,
+		NextProtos:               c.NextProtos,
+		ServerName:               c.ServerName,
+		ClientAuth:               c.ClientAuth,
+		ClientCAs:                c.ClientCAs,
+		InsecureSkipVerify:       c.InsecureSkipVerify,
+		CipherSuites:             c.CipherSuites,
+		PreferServerCipherSuites: c.PreferServerCipherSuites,
+		SessionTicketsDisabled:   c.SessionTicketsDisabled,
+		SessionTicketKey:         c.SessionTicketKey,
+		MinVersion:               c.MinVersion,
+		MaxVersion:               c.MaxVersion,
+	}
+}

tls_config_clone_go13.go

@@ -0,0 +1,29 @@
+// +build go1.3
+// +build !go1.4
+
+package mysql
+
+import "crypto/tls"
+
+func cloneTLSConfig(c *tls.Config) *tls.Config {
+	return &tls.Config{
+		Rand:                     c.Rand,
+		Time:                     c.Time,
+		Certificates:             c.Certificates,
+		NameToCertificate:        c.NameToCertificate,
+		RootCAs:                  c.RootCAs,
+		NextProtos:               c.NextProtos,
+		ServerName:               c.ServerName,
+		ClientAuth:               c.ClientAuth,
+		ClientCAs:                c.ClientCAs,
+		InsecureSkipVerify:       c.InsecureSkipVerify,
+		CipherSuites:             c.CipherSuites,
+		PreferServerCipherSuites: c.PreferServerCipherSuites,
+		SessionTicketsDisabled:   c.SessionTicketsDisabled,
+		SessionTicketKey:         c.SessionTicketKey,
+		ClientSessionCache:       c.ClientSessionCache,
+		MinVersion:               c.MinVersion,
+		MaxVersion:               c.MaxVersion,
+		CurvePreferences:         c.CurvePreferences,
+	}
+}

tls_config_clone_go14-16.go

@@ -0,0 +1,30 @@
+// +build go1.4
+// +build !go1.7
+
+package mysql
+
+import "crypto/tls"
+
+func cloneTLSConfig(c *tls.Config) *tls.Config {
+	return &tls.Config{
+		Rand:                     c.Rand,
+		Time:                     c.Time,
+		Certificates:             c.Certificates,
+		NameToCertificate:        c.NameToCertificate,
+		GetCertificate:           c.GetCertificate,
+		RootCAs:                  c.RootCAs,
+		NextProtos:               c.NextProtos,
+		ServerName:               c.ServerName,
+		ClientAuth:               c.ClientAuth,
+		ClientCAs:                c.ClientCAs,
+		InsecureSkipVerify:       c.InsecureSkipVerify,
+		CipherSuites:             c.CipherSuites,
+		PreferServerCipherSuites: c.PreferServerCipherSuites,
+		SessionTicketsDisabled:   c.SessionTicketsDisabled,
+		SessionTicketKey:         c.SessionTicketKey,
+		ClientSessionCache:       c.ClientSessionCache,
+		MinVersion:               c.MinVersion,
+		MaxVersion:               c.MaxVersion,
+		CurvePreferences:         c.CurvePreferences,
+	}
+}

tls_config_clone_go17.go

@@ -0,0 +1,32 @@
+// +build go1.7
+// +build !go1.8
+
+package mysql
+
+import "crypto/tls"
+
+func cloneTLSConfig(c *tls.Config) *tls.Config {
+	return &tls.Config{
+		Rand:                        c.Rand,
+		Time:                        c.Time,
+		Certificates:                c.Certificates,
+		NameToCertificate:           c.NameToCertificate,
+		GetCertificate:              c.GetCertificate,
+		RootCAs:                     c.RootCAs,
+		NextProtos:                  c.NextProtos,
+		ServerName:                  c.ServerName,
+		ClientAuth:                  c.ClientAuth,
+		ClientCAs:                   c.ClientCAs,
+		InsecureSkipVerify:          c.InsecureSkipVerify,
+		CipherSuites:                c.CipherSuites,
+		PreferServerCipherSuites:    c.PreferServerCipherSuites,
+		SessionTicketsDisabled:      c.SessionTicketsDisabled,
+		SessionTicketKey:            c.SessionTicketKey,
+		ClientSessionCache:          c.ClientSessionCache,
+		MinVersion:                  c.MinVersion,
+		MaxVersion:                  c.MaxVersion,
+		CurvePreferences:            c.CurvePreferences,
+		DynamicRecordSizingDisabled: c.DynamicRecordSizingDisabled,
+		Renegotiation:               c.Renegotiation,
+	}
+}

tls_config_clone_go18.go

@@ -0,0 +1,9 @@
+// +build go1.8
+
+package mysql
+
+import "crypto/tls"
+
+func cloneTLSConfig(c *tls.Config) *tls.Config{
+	return c.Clone()
+}