better logic

server/server.go

@@ -26,9 +26,12 @@ package server
 
 import (
 	"context"
+	cryptoRand "crypto/rand"
 	"crypto/tls"
+	"encoding/binary"
 	"errors"
 	"log"
+	"math/rand"
 	"mime"
 	"net/http"
 	_ "net/http/pprof"
@@ -271,8 +274,9 @@ func UseLetsEncrypt(hosts []string) OptionFn {
 			},
 		}
 
-		srvr.tlsConfig = m.TLSConfig()
-		srvr.tlsConfig.GetCertificate = m.GetCertificate
+		srvr.tlsConfig = &tls.Config{
+			GetCertificate: m.GetCertificate,
+		}
 	}
 }
 
@@ -399,6 +403,14 @@ func New(options ...OptionFn) (*Server, error) {
 	return s, nil
 }
 
+func init() {
+	var seedBytes [8]byte
+	if _, err := cryptoRand.Read(seedBytes[:]); err != nil {
+		panic("cannot obtain cryptographically secure seed")
+	}
+	rand.Seed(int64(binary.LittleEndian.Uint64(seedBytes[:])))
+}
+
 // Run starts Server
 func (s *Server) Run() {
 	listening := false

server/token.go

@@ -25,22 +25,9 @@ THE SOFTWARE.
 package server
 
 import (
-	cryptoRand "crypto/rand"
-	"encoding/binary"
 	"math/rand"
 )
 
-var seed *rand.Rand
-
-func init() {
-	var seedBytes [8]byte
-	if _, err := cryptoRand.Read(seedBytes[:]); err != nil {
-		panic("cannot obtain cryptographically secure seed")
-	}
-
-	seed = rand.New(rand.NewSource(int64(binary.LittleEndian.Uint64(seedBytes[:]))))
-}
-
 const (
 	// SYMBOLS characters used for short-urls
 	SYMBOLS = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
@@ -50,7 +37,7 @@ const (
 func token(length int) string {
 	result := ""
 	for i := 0; i < length; i++ {
-		x := seed.Intn(len(SYMBOLS) - 1)
+		x := rand.Intn(len(SYMBOLS) - 1)
 		result = string(SYMBOLS[x]) + result
 	}