Merge pull request #372 from dutchcoders/ISSUE-371

Add random-token-length config

README.md

@@ -114,6 +114,7 @@ rate-limit | request per minute  | | RATE_LIMIT |
 max-upload-size | max upload size in kilobytes  | | MAX_UPLOAD_SIZE |
 purge-days | number of days after the uploads are purged automatically | | PURGE_DAYS |   
 purge-interval | interval in hours to run the automatic purge for (not applicable to S3 and Storj) | | PURGE_INTERVAL |   
+random-token-length | length of the random token for the upload path (double the size for delete path) | 6 | RANDOM_TOKEN_LENGTH |   
 
 If you want to use TLS using lets encrypt certificates, set lets-encrypt-hosts to your domain, set tls-listener to :443 and enable force-https.
 

cmd/cmd.go

@@ -274,6 +274,12 @@ var globalFlags = []cli.Flag{
 		Value:  "",
 		EnvVar: "CORS_DOMAINS",
 	},
+	cli.Int64Flag{
+		Name:   "random-token-length",
+		Usage:  "",
+		Value:  6,
+		EnvVar: "RANDOM_TOKEN_LENGTH",
+	},
 }
 
 type Cmd struct {
@@ -377,6 +383,9 @@ func New() *Cmd {
 			options = append(options, server.RateLimit(v))
 		}
 
+		v := c.Int64("random-token-length")
+		options = append(options, server.RandomTokenLength(v))
+
 		purgeDays := c.Int("purge-days")
 		purgeInterval := c.Int("purge-interval")
 		if purgeDays > 0 && purgeInterval > 0 {

server/codec.go

@@ -26,6 +26,7 @@ package server
 
 import (
 	"math"
+	"math/rand"
 	"strings"
 )
 
@@ -34,19 +35,31 @@ const (
 	SYMBOLS = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 
 	// someone set us up the bomb !!
-	BASE = int64(len(SYMBOLS))
+	BASE = float64(len(SYMBOLS))
+
+	// init seed encode number
+	INIT_SEED = float64(-1)
 )
 
 // encodes a number into our *base* representation
 // TODO can this be made better with some bitshifting?
-func Encode(number int64) string {
-	rest := number % BASE
+func Encode(number float64, length int64) string {
+	if number == INIT_SEED {
+		seed := math.Pow(float64(BASE), float64(length))
+		number = seed + (rand.Float64() * seed) // start with seed to enforce desired length
+	}
+
+	rest := int64(math.Mod(number, BASE))
 	// strings are a bit weird in go...
 	result := string(SYMBOLS[rest])
-	if number-rest != 0 {
-		newnumber := (number - rest) / BASE
-		result = Encode(newnumber) + result
+	if rest > 0 && number-float64(rest) != 0 {
+		newnumber := (number - float64(rest)) / BASE
+		result = Encode(newnumber, length) + result
+	} else {
+		// it would always be 1 because of starting with seed and we want to skip
+		return ""
 	}
+
 	return result
 }
 

server/codec_test.go

@@ -0,0 +1,15 @@
+package server
+
+import "testing"
+
+func BenchmarkEncodeConcat(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		_ = Encode(INIT_SEED, 5) + Encode(INIT_SEED, 5)
+	}
+}
+
+func BenchmarkEncodeLonger(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		_ = Encode(INIT_SEED, 10)
+	}
+}

server/handlers.go

@@ -41,7 +41,6 @@ import (
 	"io"
 	"io/ioutil"
 	"log"
-	"math/rand"
 	"mime"
 	"net/http"
 	"net/url"
@@ -257,7 +256,7 @@ func (s *Server) postHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	token := Encode(10000000 + int64(rand.Intn(1000000000)))
+	token := Encode(INIT_SEED, s.randomTokenLength)
 
 	w.Header().Set("Content-Type", "text/plain")
 
@@ -319,7 +318,7 @@ func (s *Server) postHandler(w http.ResponseWriter, r *http.Request) {
 				return
 			}
 
-			metadata := MetadataForRequest(contentType, r)
+			metadata := MetadataForRequest(contentType, s.randomTokenLength, r)
 
 			buffer := &bytes.Buffer{}
 			if err := json.NewEncoder(buffer).Encode(metadata); err != nil {
@@ -383,13 +382,13 @@ type Metadata struct {
 	DeletionToken string
 }
 
-func MetadataForRequest(contentType string, r *http.Request) Metadata {
+func MetadataForRequest(contentType string, randomTokenLength int64, r *http.Request) Metadata {
 	metadata := Metadata{
 		ContentType:   strings.ToLower(contentType),
 		MaxDate:       time.Time{},
 		Downloads:     0,
 		MaxDownloads:  -1,
-		DeletionToken: Encode(10000000+int64(rand.Intn(1000000000))) + Encode(10000000+int64(rand.Intn(1000000000))),
+		DeletionToken: Encode(INIT_SEED, randomTokenLength) + Encode(INIT_SEED, randomTokenLength),
 	}
 
 	if v := r.Header.Get("Max-Downloads"); v == "" {
@@ -481,9 +480,9 @@ func (s *Server) putHandler(w http.ResponseWriter, r *http.Request) {
 		contentType = mime.TypeByExtension(filepath.Ext(vars["filename"]))
 	}
 
-	token := Encode(10000000 + int64(rand.Intn(1000000000)))
+	token := Encode(INIT_SEED, s.randomTokenLength)
 
-	metadata := MetadataForRequest(contentType, r)
+	metadata := MetadataForRequest(contentType, s.randomTokenLength, r)
 
 	buffer := &bytes.Buffer{}
 	if err := json.NewEncoder(buffer).Encode(metadata); err != nil {

server/server.go

@@ -187,6 +187,12 @@ func RateLimit(requests int) OptionFn {
 	}
 }
 
+func RandomTokenLength(length int64) OptionFn {
+	return func(srvr *Server) {
+		srvr.randomTokenLength = length
+	}
+}
+
 func Purge(days, interval int) OptionFn {
 	return func(srvr *Server) {
 		srvr.purgeDays = time.Duration(days) * time.Hour * 24
@@ -294,6 +300,8 @@ type Server struct {
 
 	forceHTTPs bool
 
+	randomTokenLength int64
+
 	ipFilterOptions *IPFilterOptions
 
 	VirusTotalKey    string