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Verify timestamp

Code samples for verifying the timestamps of requests.

When Canva sends an HTTP request to an app, it includes a UNIX timestamp (in seconds) of when the request was sent. To protect itself against replay attacks, an app must:

  1. Compare the timestamp of when the request was sent with when it was received.
  2. Verify that the timestamps are within 5 minutes (300 seconds) of one another.

When the timestamps are not within 5 minutes of one another, the app must reject the request by returning a 401 status code.

This page provides functions in a variety of programming languages to verify timestamps.

For step-by-step tutorials, refer to:

Examples

This section provides examples in the following languages:

Go

package main


import (
    "fmt"
    "math"
)


func IsValidTimestamp(sentAtSeconds int, receivedAtSeconds int, leniencyInSeconds int) bool {
    return int(math.Abs(float64(sentAtSeconds - receivedAtSeconds))) < leniencyInSeconds
}


func main() {
    // Valid timestamps
    fmt.Println(IsValidTimestamp(1590980773, 1590980773, 300)) // => true
    fmt.Println(IsValidTimestamp(1590980773, 1590980523, 300)) // => true
    fmt.Println(IsValidTimestamp(1590980773, 1590981023, 300)) // => true


    // Invalid timestamps
    fmt.Println(IsValidTimestamp(1590980773, 1590980273, 300)) // => false
    fmt.Println(IsValidTimestamp(1590980773, 1590981273, 300)) // => false
}
go

Java

public class Example {
    public static void main(String[] args) {
        // Valid timestamps
        System.out.println(isValidTimestamp(1590980773, 1590980773, 300)); // => true
        System.out.println(isValidTimestamp(1590980773, 1590980523, 300)); // => true
        System.out.println(isValidTimestamp(1590980773, 1590981023, 300)); // => true


        // Invalid timestamps
        System.out.println(isValidTimestamp(1590980773, 1590980273, 300)); // => false
        System.out.println(isValidTimestamp(1590980773, 1590981273, 300)); // => false
    }


    static Boolean isValidTimestamp(Integer sentAtSeconds, Integer receivedAtSeconds, Integer leniencyInSeconds) {
        return Math.abs(sentAtSeconds - receivedAtSeconds) < leniencyInSeconds;
    }
}
java

JavaScript

function isValidTimestamp(
  sentAtSeconds,
  receivedAtSeconds,
  leniencyInSeconds = 300
) {
  return Math.abs(sentAtSeconds - receivedAtSeconds) < leniencyInSeconds;
}


// Valid timestamps
console.log(isValidTimestamp(1590980773, 1590980773)); // => true
console.log(isValidTimestamp(1590980773, 1590981023)); // => true
console.log(isValidTimestamp(1590980773, 1590980523)); // => true


// Invalid timestamps
console.log(isValidTimestamp(1590980773, 1590980273)); // => false
console.log(isValidTimestamp(1590980773, 1590981273)); // => false
javascript

PHP

<?php


function isValidTimestamp(int $sentAtSeconds, int $receivedAtSeconds, int $leniencyInSeconds = 300) {
    return abs($sentAtSeconds - $receivedAtSeconds) < $leniencyInSeconds;
}


// Valid timestamps
var_dump(isValidTimestamp(1590980773, 1590980773)); // => bool(true)
var_dump(isValidTimestamp(1590980773, 1590980523)); // => bool(true)
var_dump(isValidTimestamp(1590980773, 1590981023)); // => bool(true)


// Invalid timestamps
var_dump(isValidTimestamp(1590980773, 1590980273)); // => bool(false)
var_dump(isValidTimestamp(1590980773, 1590981273)); // => bool(false)


?>
php

Python

def is_valid_timestamp(sent_at_seconds, received_at_seconds, leniency_in_seconds = 300):
    return abs(sent_at_seconds - received_at_seconds) < leniency_in_seconds


# Valid timestamps
print(is_valid_timestamp(1590980773, 1590980773)) # => True
print(is_valid_timestamp(1590980773, 1590980523)) # => True
print(is_valid_timestamp(1590980773, 1590981023)) # => True


# Invalid timestamps
print(is_valid_timestamp(1590980773, 1590980273)) # => False
print(is_valid_timestamp(1590980773, 1590981273)) # => False
python

Ruby

def is_valid_timestamp(sent_at_seconds, received_at_seconds, leniency_in_seconds = 300)
    (sent_at_seconds - received_at_seconds).abs < leniency_in_seconds
end


# Valid timestamps
puts is_valid_timestamp(1590980773, 1590980773) # => true
puts is_valid_timestamp(1590980773, 1590980523) # => true
puts is_valid_timestamp(1590980773, 1590981023) # => true


# Invalid timestamps
puts is_valid_timestamp(1590980773, 1590980273) # => false
puts is_valid_timestamp(1590980773, 1590981273) # => false
ruby

TypeScript

function isValidTimestamp(
  sentAtSeconds: number,
  receivedAtSeconds: number,
  leniencyInSeconds: number = 300
): boolean {
  return Math.abs(sentAtSeconds - receivedAtSeconds) < leniencyInSeconds;
}


// Valid timestamps
console.log(isValidTimestamp(1590980773, 1590980773)); // => true
console.log(isValidTimestamp(1590980773, 1590981023)); // => true
console.log(isValidTimestamp(1590980773, 1590980523)); // => true


// Invalid timestamps
console.log(isValidTimestamp(1590980773, 1590980273)); // => false
console.log(isValidTimestamp(1590980773, 1590981273)); // => false
javascript