Google Sign in for Android - Release vs Debug

Question

So currently, I am trying to implement google sign-in .. I have followed the instructions on developer.android.com .. I am having a weird issue and I see several people on SO talk about this but it never gets anywhere so I am posting this here ...

I am able to use google sign in AFTER I generate a signed apk; and if I don't follow that method I am not able to use google sign in (i.e if I plug my phone in and hit run on android studio, google sign in tells me my request result was unsuccessful)

My question is 1) Whats really going on here? and 2) How can I use google sign in without needing to generate a signed apk each time ..

UPDATE

I believe it is because of the SHA-1 hash function that is either run on the debug keystore vs release ...

Answer 1

After signing your apk is using your signed SHA1 for using google services..like gmail login..

so your debug SHA1 will not work..in this case.

Answer to your first question..i think your OAuth 2.0 client IDs SHA1 is for release version. so in debug mode it is not working

And your second question yes you can use google sign in without generating signed apk each time..

For this first find your debug SHA1

1. Click on the Gradle tab on the right hand side of the view.
2. Go to the ROOT folder -> Tasks -> android -> signingReport
3. Double click, this will build with the signingReport and post in your bottom view your SHA1.

Now go to

1. https://console.developers.google.com

2. select credential tab on leftside

3. select OAuth 2.0 client IDs at bottom and select Android client 1

4. Now change the release SHA1 to your debug SHA1 and save it
5. Now your google sign in work in debug mode also.

N.B: during build apk change your Build variant from release to debug

And during release you have to replace back your release SHA1 in the OAuth2.0