Understanding hashing in cookies

Question

I am using a website whose cookies are as following (when I'm as a guest at 3 different instances in increasing order of time) :

1. eyJ0YWxrX3N0YXRlIjowfQ\075\075|1497742098|514507d23a215fcea83c80608ba67ce4a4946a6e
2. eyJ0YWxrX3N0YXRlIjowfQ\075\075|1497742995|a2d97bc48c9411e7afd09fd554646e1f63c30c54
3. eyJ0YWxrX3N0YXRlIjowfQ\075\075|1497743233|b01171747934f116c7a3af5c1a3bde989f69e03d

When I logged in from 2 different account it changed to following:

First account -"eyJ1c2VyX2lkIjoiMTE1Mjg2ODM5OTMyMzI1ODA5OTg4IiwidXNlcl9uYW1lIjoiU2FtIiwidGFsa19zdGF0ZSI6MH0\075|1497741945|7a7904970733851fc11eaa5ee456c4ee939f510f"

Second account - "eyJ1c2VyX2lkIjoiMTA3NjYzODAwMzg1MDkxODU5MzAwIiwidXNlcl9uYW1lIjoiQ3JhenlSdWciLCJ0YWxrX3N0YXRlIjowfQ\075\075|1497742305|2666b0847f1042c1d40769a19ae11741b82551bb"

I can't make out anything out of it except the fact that |1497742305| seem to be sort of timestamp. I have tried md5, base64 but neither of the string has any of them.

What encryption is used ? How can I extract information from it ? Can someone help me out , I am new to all this.

Answer 1

The two vertical bars hints towards 3 separate parts of the cookie. It seems that the first part is a base64 encoded json object. For the first part of the cookie no. 1 that would be:

eyJ0YWxrX3N0YXRlIjowfQ\075\075

which decoded is:

{"talk_state":0}

nb: each "\075" is the unicode value for ascii character "K".

Post login, the first part becomes:

{"user_id":"115286839932325809988","user_name":"Sam","talk_state":0}

for the base64 string

eyJ1c2VyX2lkIjoiMTA3NjYzODAwMzg1MDkxODU5MzAwIiwidXNlcl9uYW1lIjoiQ3JhenlSdWciLCJ0YWxrX3N0YXRlIjowfQ\075\075

The second part as you suspected, is a timestamp in epoch date format, where 1497742098 is Mon, 19 Jun 2017 06:16:57 GMT

The last part, I am not too sure. This could be SHA1 value of some data used as an integrity check server side. You may need to play around with creating different SHA1 values using different combination of data known so far to get a matching value.