Implementing Google Workspace SSO Configuration

Overview

Single Sign-On (SSO) for Google Workspace allows organizations to authenticate users through their existing identity provider (IdP) such as Okta, Azure AD (Microsoft Entra ID), or ADFS, rather than managing separate Google passwords. This is implemented using SAML 2.0 protocol where Google Workspace acts as the Service Provider (SP) and the organization's IdP handles authentication. SSO centralizes credential management, enforces MFA policies at the IdP, and enables immediate access revocation when users leave the organization.

Prerequisites

Google Workspace Business, Enterprise, or Education edition
Super Admin access to Google Admin Console
Identity Provider with SAML 2.0 support (Okta, Azure AD, ADFS, Ping Identity)
IdP signing certificate (X.509 PEM format, RSA or DSA)
DNS verification for the Google Workspace domain

Core Concepts

SAML 2.0 SSO Flow

User navigates to Google Workspace app (Gmail, Drive, etc.)
        │
        ├── Google checks: Is SSO configured for this domain?
        │
        ├── YES → Redirect user to IdP Sign-In Page URL
        │          (SAML AuthnRequest sent via browser redirect)
        │
        ├── User authenticates at IdP (credentials + MFA)
        │
        ├── IdP generates SAML Response with signed assertion
        │
        ├── Browser POSTs SAML Response to Google ACS URL:
        │   https://www.google.com/a/{domain}/acs
        │
        ├── Google validates SAML signature against uploaded certificate
        │
        └── User is granted access to Google Workspace

Key SAML Parameters

Parameter	Value
ACS URL	`https://www.google.com/a/{your-domain}/acs`
Entity ID	`google.com/a/{your-domain}` or `google.com`
NameID Format	`urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress`
NameID Value	User's primary Google Workspace email
Binding	HTTP-POST (for ACS), HTTP-Redirect (for SSO URL)

Implementation Steps

Step 1: Prepare the Identity Provider

For Okta:

Navigate to Applications > Add Application > Search "Google Workspace"
Configure the Google Workspace app with your domain
Assign users/groups to the application
Download the IdP metadata or note: SSO URL, Entity ID, Certificate

For Azure AD (Microsoft Entra ID):

Navigate to Enterprise Applications > New Application > Google Cloud/Workspace
Configure Single sign-on > SAML
Set Basic SAML Configuration:
- Identifier (Entity ID): google.com
- Reply URL (ACS): https://www.google.com/a/{your-domain}/acs
- Sign on URL: https://www.google.com/a/{your-domain}/ServiceLogin
Download Federation Metadata XML or Certificate (Base64)

For ADFS:

Add Relying Party Trust using federation metadata
Configure claim rules to pass NameID as email address
Export the token-signing certificate

Step 2: Configure Google Workspace SSO

Sign in to Google Admin Console (admin.google.com) as Super Admin
Navigate to Security > Authentication > SSO with third-party IdP
Click "Add SSO profile" or configure the default profile

Third-Party SSO Profile Settings:

Setting	Value
Set up SSO with third-party IdP	Enabled
Sign-in page URL	IdP's SAML SSO endpoint (e.g., `https://idp.example.com/sso/saml`)
Sign-out page URL	IdP's logout URL (e.g., `https://idp.example.com/slo`)
Change password URL	IdP's password change URL
Verification certificate	Upload IdP's X.509 signing certificate
Use a domain-specific issuer	Enabled (uses `google.com/a/{domain}` as entity ID)

Step 3: Assign SSO Profile to Users

SSO profiles can be applied at different scopes:

Organization-wide (all users)
    │
    ├── Org Unit level (specific departments)
    │   ├── Engineering OU → SSO via Okta
    │   ├── Marketing OU → SSO via Azure AD
    │   └── Contractors OU → SSO via specific IdP
    │
    └── Group level (specific security groups)
        └── VPN Users → SSO with additional MFA

Navigate to Security > Authentication > SSO with third-party IdP
Select the SSO profile to assign
Choose organizational units or groups
Save and wait for propagation (up to 24 hours, typically minutes)

Step 4: Configure Network Masks (Optional)

Network masks control when SSO is enforced based on the user's IP:

If the user's IP matches a network mask, they use Google's sign-in page
If the user's IP does NOT match, they are redirected to the IdP

This is useful for allowing direct Google login from corporate network while enforcing SSO for external access.

Step 5: Test SSO

Open an incognito browser window
Navigate to https://mail.google.com/a/{your-domain}
Verify redirect to IdP sign-in page
Authenticate at the IdP
Verify successful redirect back to Google Workspace
Test sign-out flow redirects to IdP logout page
Test with user not assigned in IdP (should fail)

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