Google OAuth token exchange returns invalid_code - oauth

Question

I have been implementing the Google web server OAuth flow, but when I attempted to exchange the authorization code with access token, it always complains "invalid_code".
Here is the issue:
Step 1:
Redirect one of our pages to 'https://accounts.google.com/o/oauth2/auth?scope=email&redirect_uri=https%3A%2F%2Fmyurl.com%2Fcallback&response_type=code&client_id=some_client_id'
Step 2:
The redirection happens and google would redirect to our url
https://myurl.com/callback?code=somecode
Step 3:
curl -X POST --data "code=somecode&client_id=some_client_id&some_client_secret=some_client_secret&redirect_uri=https://myurl.com/callback&grant_type=authorization_code" https://accounts.google.com/o/oauth2/token -v --trace-ascii /dev/stout
The response comes back:
HTTP 400 Bad request
{
"error" : "invalid_grant",
"error_description" : "Invalid code."
}
Can someone help me with this issue? Thanks!

Answer 1

The life span of authorization code is only 10 mins,and can only be used one time. So do these checks:
Do you use it 10 min later? If so, use it in 10 mins.
Have you used it before? If so, obtain a new one and then use it.
Is you server time in sync with Google OAuth server's? If not, change your time.

Answer 2

I was using http://localhost:8080 as my redirect url since I was just trying out their examples. And my json file contents had this:
"redirect_uris": [
"http://localhost:8080"
],
"javascript_origins": [
"http://localhost:8080"
]
In the developer console I had the redirect_uri set to "http://localhost:8080" and I was getting the same error. I changed it to "http://localhost:8080/" and then it started working. (Essentially adding a '/' at the end.)
Hope this helps!