Configuration OAuth Providers

Purpose

Use this skill to configure oauth identity provider <name> blocks. The Caddyfile syntax is authoritative in caddyfile_identity.go and caddyfile_identity_provider_oauth.go; it delegates to the shared upstream OAuth parser. The provisioning behavior is authoritative in the module selected by go.mod and any active replacement, especially pkg/idp/oauth/config.go. A sibling checkout is read-only context and may differ from that selection; inspect go list -m -json github.com/greenpau/go-authcrunch.

Do not use this skill for sso provider <name> blocks. Those configure the SSO app/SAML role-assumption feature and belong in configuration-sso-app. Also do not route saml identity provider <name> blocks here; their headers share the dispatcher but SAML uses the local go-authcrunch/pkg/idp/saml implementation.

Read shared parsing, grammar compatibility, and trust when changing OAuth directives, issuer/audience, keys, or parser validation.

The qualified operator examples include an actual TLS journey using explicit issuer/access-token audience and static Ed25519 keys. Upstream login does not create downstream OP or local portal-refresh authority.

Use assets/config/home.Caddyfile as the nearest repository example for Azure, GitHub, and LinkedIn OAuth providers.

Shape

{
	security {
		oauth identity provider azure {
			realm azure
			driver azure
			tenant_id {env.AZURE_APP_TENANT_ID}
			client_id {env.AZURE_APP_CLIENT_ID}
			client_secret {env.AZURE_APP_CLIENT_SECRET}
			scopes openid email profile
			enable id token cookie id_token AZURE_ID_TOKEN
		}

		oauth identity provider github {
			realm github
			driver github
			client_id {env.GITHUB_APP_CLIENT_ID}
			client_secret {env.GITHUB_APP_CLIENT_SECRET}
			icon github priority 100
			disable pkce
		}

		authentication portal myportal {
			enable identity provider azure github
		}
	}
}

The identity provider name must match the portal's enable identity provider <name> value. The realm is what user transforms usually match:

transform user {
	match realm github
	action add role authp/user
}

Supported Drivers

go-authcrunch currently supports these OAuth drivers:

azure, cognito, discord, facebook, generic, github, gitlab, google, linkedin,
nextcloud, okta

Every OAuth provider needs realm, driver, client_id, and client_secret; the Caddyfile provider name becomes authcrunch's config Name. Use Caddy placeholders or secrets for client secrets. For runtime references, retain the app's oauth_provider_directives snapshot in adapted JSON: it recalculates driver defaults after resolving the original arguments. See runtime references.

The shortcut form is supported only for github, google, and facebook:

oauth identity provider github {env.GITHUB_APP_CLIENT_ID} {env.GITHUB_APP_CLIENT_SECRET}

Prefer full blocks when adding icons, scopes, cookie behavior, or provider toggles.

When scopes is omitted, authcrunch defaults by driver:

• github: read:user.
• facebook: email.
• discord: identify.
• nextcloud: email.
• google, cognito, linkedin, and the fallback for azure, gitlab, okta, and generic: openid email profile.

Provider Notes

• Azure: include tenant_id when targeting a tenant. If omitted, authcrunch defaults to common and computes Azure base and metadata URLs from it.
• Google: authcrunch fills Google base and metadata URLs. If client_id has no dot, authcrunch appends .apps.googleusercontent.com.
• GitHub, Facebook, and Discord: authcrunch fills authorization and token URLs and requires only access_token in the token response.
• GitLab: authcrunch defaults domain_name to gitlab.com and computes base and metadata URLs from it.
• LinkedIn: defaults to OpenID-style scopes; assets/config/home.Caddyfile enables an id token cookie for this provider.
• Okta: requires domain_name and server_id even when overriding URLs. If base_auth_url is omitted, authcrunch computes base and metadata URLs from those fields; if base_auth_url is supplied manually, also supply metadata_url unless using the explicit static-key path below.
• Cognito: requires region and user_pool_id; authcrunch computes base and metadata URLs from them.
• Nextcloud: set base_auth_url; authcrunch derives the authorization and token URLs from it.
• Generic: always set a parseable base_auth_url. Then either set metadata_url for discovery, or set authorization_url, token_url, and jwks key <kid> <pem_path> together. Static and combined key sources retain TLS, nonce, PKCE, and signature verification. Explicit static IDs override colliding discovery keys.

GitHub identity claims

With go-authcrunch v1.3.8, authenticated GitHub /user IDs also appear as the lossless string claim github_id. Numeric metadata.id and login-based sub remain unchanged. A rename therefore does not change ID matching; missing IDs cannot match, and malformed supplied IDs reject login.

For organization claims, add user_org_filters .* (or narrower login-name regexes) inside the GitHub provider. Only returned organizations passing those filters populate github_orgs; existing github.com/<org>/members groups remain. No filter means no organization lookup. The existing endpoint exposes a single page of public memberships; this feature adds no pagination or private membership discovery, and adding read:org alone does not change the endpoint.

Use configuration-authentication-user-transforms to assign roles with match github id <exact|regex> <value> and match github org <exact|regex> <value>. The actual backend driver establishes trust; naming another driver's realm github does not grant these claims. Transforms cannot mutate either claim, including through nested actions. TestCaddyGithubTransformsE2E qualifies these contracts through Caddy and a local TLS OAuth fixture, including lookup denial and provider impersonation.

Provider-Side Claim Notes

Some OAuth failures require changes in the upstream provider console, not the Caddyfile parser:

• Discord: the default identify scope yields the Discord user identity. Add email for email claims, guilds for guild membership, and guilds.members.read for guild role checks. When user_group_filters matches a guild, authcrunch can emit roles such as discord.com/<guild_id>/members, discord.com/<guild_id>/admins, and discord.com/<guild_id>/role/<role_id> for transform matching.
• GitHub: configure App account permissions for email addresses with read-only access when /whoami or transforms need email claims. Without this provider permission and user consent, email may be absent even when the Caddyfile is valid.
• Keycloak: create realm roles or groups that correspond to application roles, assign users to them, and add client mappers for email and groups/roles so the claims appear in tokens or userinfo. Missing mappers often look like a transform bug but are provider-side configuration.
• Cognito: configure required user-pool fields, app client callback/sign-out URLs, domain, and custom attributes before login. The legacy docs note that custom attributes such as custom:roles and custom:timezone may not appear in the issued portal token without additional provider/userinfo extraction behavior.
• Ping Identity, Auth0, OneLogin, and other hosted providers often require console-side callback URL, logout URL, scope, and claim mapping setup even when the generic Caddyfile shape is correct.

Common Options

The parser accepts single-value OAuth fields such as realm, driver, tenant_id, domain_name, client_id, client_secret, server_id, base_auth_url, metadata_url, authorization_url, token_url, issuer, access_token_audience, region, user_pool_id, identity_token_field_name, identity_token_cookie_name, and user_info_roles_field_name. Shared keys also accept separate words. Recognized syntax with a shared-validation restriction:

logout_url <logout_url>
logout url <logout_url>

These are aliases for one scalar in upstream pkg/idp/oauth/parser/fields.go. The selected v1.3.4 shared validator in pkg/idp/config.go excludes that field, so Caddy adaptation rejects it. Keep both forms documented with that status; exclude them from runnable examples until shared validation supports them. enable logout / logout enabled remains a separate supported switch.

It accepts numeric retry and delayed-start fields:

delay_start 10
retry_attempts 5
retry_interval 5

With delay_start but no retry settings, authcrunch defaults to two attempts and uses delay_start as the retry interval. With retry_attempts but no interval, authcrunch defaults the interval to 5 seconds.

It accepts repeatable/list fields:

scopes openid email profile
user_group_filters "^github.com/example/"
user_org_filters "^example-org$"
response_type code
required_token_fields access_token id_token
jwks key main testdata/oauth/87329db33bf_pub.pem

For generic OpenID providers with a discovered userinfo_endpoint, choose one extraction line below; optionally set the roles field:

extract email profile roles from userinfo
extract all from userinfo
user_info_roles_field_name roles

Accepted toggles include:

disable metadata discovery
disable key verification
disable pass grant type
disable response type
disable scope
disable nonce
disable tls verification
disable email claim check
disable pkce
enable accept header
enable js callback
enable logout
enable id token cookie id_token AZURE_ID_TOKEN

disable metadata discovery is parsed into metadata_discovery_disabled, but current authcrunch OAuth provider setup does not use that flag by itself to skip discovery. To avoid metadata fetching, configure explicit URLs as required by the driver and account for JWKS behavior.

External logout is separate from local portal logout. enable logout enables provider-specific logout handling when the driver implements it. It does not make typed-only logout_url available through Caddy's shared dispatcher.

For id token cookies, these are alternative spaced Caddyfile forms:

enable id token cookie
enable id token cookie id_token
enable id token cookie id_token AZURE_ID_TOKEN

The first optional value is the token response field to copy and must be id_token or access_token; the second optional value is the cookie name. When the cookie name is omitted, authcrunch uses AUTHP_ID_TOKEN for the provider identity-token cookie.

Review Checklist

Check generated OAuth provider entries against these code-backed constraints:

• Use oauth identity provider <name>, not sso provider <name>.
• Include realm, driver, client_id, and client_secret.
• Choose a driver supported by go-authcrunch.
• Add provider-specific required fields for Okta, Cognito, Nextcloud, and generic providers.
• For generic providers, include base_auth_url plus either metadata_url or explicit authorization_url, token_url, and static jwks key entries.
• Use enable identity provider <name> in the authentication portal.
• Use match realm <realm> in transforms when assigning roles after OAuth login.
• Use the spaced form enable id token cookie ...; avoid inventing enable id_token cookie.
• Treat disable metadata discovery as a parsed flag, not as sufficient runtime behavior by itself.
• Keep client secrets in placeholders or secret lookups.

Fixtures

Use these examples:

• assets/config/home.Caddyfile for Azure, GitHub, and LinkedIn.
• testdata/caddyfile_adapt/testcase_authenticate_with_oauth.Caddyfile for OAuth plus portal and authorization wiring.
• caddyfile_identity_provider_oauth.go for Caddy translations into the shared parser, with grammar inventory and validation in the linked reference.
• go-authcrunch/pkg/idp/oauth/config.go for driver defaults and validation.