'How to authenticate with Google Service Account credentials using Postman and HTTPS?

I have read these documents:

I have stored the google-secrets.json credentials of the service account. However I can't understand how to send the request with the credentials to get the auth token or api key.

There are only libraries published that do this.

How do I setup authentication with HTTPS in Postman?

Solution 1:^[1]

found.

signed it with RS256 on JWT.io with params

HEADER:

{
  "alg": "RS256",
  "typ": "JWT",
  "kid": "your_private_key_id"
}

PAYLOAD:

{
  "iss": "your_client_email_of_service_account",
  "sub": "your_client_email_of_service_account",
  "aud": "https://www.googleapis.com/oauth2/v4/token",
  "scope": "https://www.googleapis.com/auth/devstorage.read_only",
  "iat": current_unix_time,
  "exp": current_unix_time+3600
}

VERIFY SIGNATURE

your_private_key in last field (without \n)

got encoded key

and then

POST /oauth2/v4/token HTTP/1.1

Host: www.googleapis.com

Content-Type: application/x-www-form-urlencoded

Cache-Control: no-cache

grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Ajwt-bearer&assertion=ENCODED_KEY_FROM_JWT.IO

and i got response

{

    "access_token": "ya21.c.ElrSBodwuWANeh7Q0-zlXpOxqm9-uEszPElsY2tvoG5aPxRgOkasN5G2sMgj3iosPVbRYk1wXw_DcBnm2FtuNBlZpv_wCC0YS5pWMykR8Ouf5CZg-8OK842rvfk",

    "expires_in": 3600,

    "token_type": "Bearer"

}

also dont forget give a priveleges to your service account for read in storage

Solution 2:^[2]

This is answered very well by Gordon Thompson in the medium article Google Authentication with Postman covering three different methods:

Using oauth2l CLI
Configuring Postman with OAuth 2 and User Credentials
Configuring Postman to use a pre-request script. This will auto-generate Google Access and ID tokens from a Service Account key and save it in Postman. Based on the work of Denis Loginov, the gist is available here:

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1	Community
Solution 2	intotecho

'How to authenticate with Google Service Account credentials using Postman and HTTPS?

Solution 1:[1]

Solution 2:[2]

Sources

Related Questions

Solution 1:^[1]

Solution 2:^[2]