Converting an s3 bucket policy to base64 from JSON in node.js

Question

I'm trying to encode an Amazon s3 bucket policy in base64 in node.js for the signature (more specifically the StringToSign), but can't seem to get the code right.

I'm using a default policy provided by amazon to test with because they provide the correct base64 encoding. ( The example given by amazon )

Their output is eyAiZXhwaXJhdGlvbiI6ICIyMDE1........ (Keeping it short because it's quite long)

I keep getting eyJleHBpcmF0aW9uIjoiMjAxNS0xMi0zMFQx.....

my code to generate this is:

var policyString = JSON.stringify(policy)
var policyBytes = utf8.encode(policyString)
var stringToSign = base64.encode(policyBytes)

where policy is a variable holding the amazon policy in JSON format, and utf8 and base64 are node modules.

This might sound like a novice question but I've been staring at it for awhile now and any hlep would be appreciated!

Answer 1

I decoded the current partial values you have provided

eyAiZXhwaXJhdGlvbiI6ICIyMDE1
eyJleHBpcmF0aW9uIjoiMjAxNS0xMi0zMFQx

Respective outputs were:

{ "expiration": "2015
{"expiration":"2015-12-30T1

As you can see, in your policyString you have removed some spaces. This is the reason for you to get a different output