Add RandomHex() helper

cmd/itemAdd.go

@@ -1,8 +1,6 @@
 package cmd
 
 import (
-	"crypto/rand"
-	"encoding/hex"
 	"encoding/json"
 	"log"
 
@@ -70,11 +68,7 @@ func itemAdd(
 	}
 	// Default id to random hex string
 	if id == "" {
-		bytes := make([]byte, 16)
+		id = core.RandomHex(16)
-		if _, err := rand.Read(bytes); err != nil {
-			log.Fatalf("error: failed to generate id: %v", err)
-		}
-		id = hex.EncodeToString(bytes)
 	}
 
 	var itemActions core.Actions

core/item.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
+	"math/rand"
 	"time"
 )
 
@@ -105,3 +106,13 @@ var AvailableFormats = map[string]string{
 	"json":      "Full item JSON",
 	"short":     "Item source and id",
 }
+
+const hexDigits = "0123456789abcdef"
+
+func RandomHex(n int) string {
+	bytes := make([]byte, n)
+	for i := range bytes {
+		bytes[i] = hexDigits[rand.Intn(len(hexDigits))]
+	}
+	return string(bytes)
+}

web/item.go

@@ -1,8 +1,6 @@
 package web
 
 import (
-	"crypto/rand"
-	"encoding/hex"
 	"fmt"
 	"log"
 	"net/http"
@@ -157,11 +155,7 @@ func (env *Env) addItem(writer http.ResponseWriter, req *http.Request) {
 		}
 	}
 
-	bytes := make([]byte, 16)
+	id := core.RandomHex(16)
-	if _, err := rand.Read(bytes); err != nil {
-		http.Error(writer, fmt.Sprintf("error: failed to generate id: %v", err), 500)
-	}
-	id := hex.EncodeToString(bytes)
 
 	title := req.PostForm.Get("title")
 	link := req.PostForm.Get("link")

web/login.go

@@ -15,13 +15,13 @@ import (
 var AuthCookieName string = "intake_auth"
 var AuthDuration time.Duration = time.Hour * 24 * 7
 
-func newSession(db core.DB) (string, error) {
+func newSession(db core.DB) (session string, err error) {
 	bytes := make([]byte, 32)
-	_, err := rand.Read(bytes)
+	_, err = rand.Read(bytes)
 	if err != nil {
 		return "", err
 	}
-	session := fmt.Sprintf("%x", bytes)
+	session = fmt.Sprintf("%x", bytes)
 	expires := int(time.Now().Add(AuthDuration).Unix())
 	_, err = db.Exec(`
 		insert into sessions (id, expires)