Add new tool file referencelib

tools/referencelib.go

@@ -0,0 +1,76 @@
+/*	==========================================================================
+	Golib Repo
+	Filename: referencelib.go
+	Owner: Sergiy Safronov
+	Source : github.com/CoderSergiy/golib/tools
+	Purpose: Methods to generate random reference
+	=============================================================================
+*/
+
+package tools
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+)
+
+/****************************************************************************************
+ *
+ * Function : GenerateRandomBytes
+ *
+ *  Purpose : Generate Random Bytes for reference purpose
+ *
+ *    Input : n int - specify size of the buffer
+ *
+ *	 Return : []]byte - securely generated random bytes
+ *			  error - if happened, nil otherwise
+ */
+func GenerateRandomBytes(n int) ([]byte, error) {
+	b := make([]byte, n)
+	_, err := rand.Read(b)
+	// Note that err == nil only if we read len(b) bytes.
+	if err != nil {
+		return nil, err
+	}
+
+	return b, nil
+}
+
+/****************************************************************************************
+ *
+ * Function : GenerateRandomString
+ *
+ *  Purpose : Generate Random String for reference purpose
+ *
+ *    Input : n int - size of the returning string
+ *
+ *	 Return : string - securely generated random string
+ *			  error - if happened, nil otherwise
+ */
+func GenerateRandomString(n int) (string, error) {
+	const letters = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-"
+	bytes, err := GenerateRandomBytes(n)
+	if err != nil {
+		return "", err
+	}
+	for i, b := range bytes {
+		bytes[i] = letters[b%byte(len(letters))]
+	}
+	return string(bytes), nil
+}
+
+/****************************************************************************************
+ *
+ * Function : GenerateRandomStringURLSafe
+ *
+ *  Purpose : Generate URL-safe, base64 encoded random string
+ *
+ *    Input : n int - size of the returning string
+ *
+ *	 Return : string - securely generated random bytes
+ *			  error - if happened, nil otherwise
+ */
+func GenerateRandomStringURLSafe(n int) (string, error) {
+	b, err := GenerateRandomBytes(n)
+	return base64.URLEncoding.EncodeToString(b), err
+}