Add support for custom tls.Configs

README.md

@@ -113,7 +113,7 @@ Possible Parameters are:
   * `parseTime`: `parseTime=true` changes the output type of `DATE` and `DATETIME` values to `time.Time` instead of `[]byte` / `string`
   * `strict`: Enable strict mode. MySQL warnings are treated as errors.
   * `timeout`: **Driver** side connection timeout. The value must be a string of decimal numbers, each with optional fraction and a unit suffix ( *"ms"*, *"s"*, *"m"*, *"h"* ), such as *"30s"*, *"0.5m"* or *"1m30s"*. To set a server side timeout, use the parameter [`wait_timeout`](http://dev.mysql.com/doc/refman/5.6/en/server-system-variables.html#sysvar_wait_timeout).
-  * `tls`: `true` enables TLS / SSL encrypted connection to the server. Use `skip-verify` if you want to use a self-signed or invalid certificate (server side)
+  * `tls`: `true` enables TLS / SSL encrypted connection to the server. Use `skip-verify` if you want to use a self-signed or invalid certificate (server side). Use a custom value registered with [`mysql.RegisterTLSConfig`](http://godoc.org/github.com/go-sql-driver/mysql#RegisterTLSConfig).
 
 All other parameters are interpreted as system variables:
   * `autocommit`: *"SET autocommit=`value`"*

driver_test.go

@@ -1,6 +1,7 @@
 package mysql
 
 import (
+	"crypto/tls"
 	"database/sql"
 	"fmt"
 	"io"
@@ -840,7 +841,7 @@ func TestStrict(t *testing.T) {
 }
 
 func TestTLS(t *testing.T) {
-	runTests(t, dsn+"&tls=skip-verify", func(dbt *DBTest) {
+	tlsTest := func(dbt *DBTest) {
 		if err := dbt.db.Ping(); err != nil {
 			if err == errNoTLS {
 				dbt.Skip("Server does not support TLS")
@@ -861,7 +862,15 @@ func TestTLS(t *testing.T) {
 				dbt.Fatal("No Cipher")
 			}
 		}
+	}
+
+	runTests(t, dsn+"&tls=skip-verify", tlsTest)
+
+	// Verify that registering / using a custom cfg works
+	RegisterTLSConfig("custom-skip-verify", &tls.Config{
+		InsecureSkipVerify: true,
 	})
+	runTests(t, dsn+"&tls=custom-skip-verify", tlsTest)
 }
 
 // Special cases

utils.go

@@ -77,6 +77,46 @@ func (nt NullTime) Value() (driver.Value, error) {
 	return nt.Time, nil
 }
 
+var tlsConfigMap map[string]*tls.Config
+
+// Registers a custom tls.Config to be used with sql.Open.
+// Use the key as a value in the DSN where tls=value.
+//
+//  rootCertPool := x509.NewCertPool()
+//  pem, err := ioutil.ReadFile("/path/ca-cert.pem")
+//  if err != nil {
+//      log.Fatal(err)
+//  }
+//  if ok := rootCertPool.AppendCertsFromPEM(pem); !ok {
+//      log.Fatal("Failed to append PEM.")
+//  }
+//  clientCert := make([]tls.Certificate, 0, 1)
+//  certs, err := tls.LoadX509KeyPair("/path/client-cert.pem", "/path/client-key.pem")
+//  if err != nil {
+//      log.Fatal(err)
+//  }
+//  clientCert = append(clientCert, certs)
+//  mysql.RegisterTLSConfig("custom", &tls.Config{
+//      RootCAs: rootCertPool,
+//      Certificates: clientCert,
+//  })
+//  db, err := sql.Open("mysql", "user@tcp(localhost:3306)/test?tls=custom")
+//
+func RegisterTLSConfig(key string, config *tls.Config) {
+	if tlsConfigMap == nil {
+		tlsConfigMap = make(map[string]*tls.Config)
+	}
+	tlsConfigMap[key] = config
+}
+
+// Removes tls.Config associated with key.
+func DeregisterTLSConfig(key string) {
+	if tlsConfigMap == nil {
+		return
+	}
+	delete(tlsConfigMap, key)
+}
+
 // Logger
 var (
 	errLog *log.Logger
@@ -152,6 +192,9 @@ func parseDSN(dsn string) (cfg *config, err error) {
 						cfg.tls = &tls.Config{}
 					} else if strings.ToLower(value) == "skip-verify" {
 						cfg.tls = &tls.Config{InsecureSkipVerify: true}
+					// TODO: Check for Boolean false
+					} else if tlsConfig, ok := tlsConfigMap[value]; ok {
+						cfg.tls = tlsConfig
 					}
 
 				default: