// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package openid

import (
	"crypto"
	"crypto/ecdsa"
	"crypto/ed25519"
	"crypto/elliptic"
	"crypto/rsa"
	"encoding/base64"
	"errors"
	"fmt"
	"math/big"
)

// JWKS - https://tools.ietf.org/html/rfc7517

	clientSecret string
)

func init() {
	flag.StringVar(&stsEndpoint, "sts-ep", "http://localhost:9000", "STS endpoint")
	flag.StringVar(&idpEndpoint, "idp-ep", "http://localhost:8080/auth/realms/minio/protocol/openid-connect/token", "IDP token endpoint")
	flag.StringVar(&clientID, "cid", "", "Client ID")
	flag.StringVar(&clientSecret, "csec", "", "Client secret")
}

func getTokenExpiry() (*credentials.ClientGrantsToken, error) {

    """
    METHOD = 'assume-role-client-grants'
    CANONICAL_NAME = 'AssumeRoleClientGrants'

    def __init__(self, cid, csec,
                 idp_ep='http://localhost:8080/auth/realms/minio/protocol/openid-connect/token',
                 sts_ep='http://localhost:9000'):
        self.cid = cid
        self.csec = csec
        self.idp_ep = idp_ep
        self.sts_ep = sts_ep

The authentication flow is similar to that of OpenID, however the token is "opaque" to MinIO - it is simply sent to the plugin for verification. CAVEAT: There is no console UI integration for this method of authentication and it is intended primarily for machine authentication.

	"github.com/minio/minio/internal/config"
	"github.com/minio/minio/internal/config/etcd"
	xldap "github.com/minio/minio/internal/config/identity/ldap"
	"github.com/minio/minio/internal/config/identity/openid"
	idplugin "github.com/minio/minio/internal/config/identity/plugin"
	polplugin "github.com/minio/minio/internal/config/policy/plugin"
	"github.com/minio/minio/internal/config/storageclass"

	TotalRefreshFailures            uint64

	sync.Mutex

	iamRefreshInterval time.Duration

	LDAPConfig   xldap.Config  // only valid if usersSysType is LDAPUsers
	OpenIDConfig openid.Config // only valid if OpenID is configured
	STSTLSConfig xtls.Config   // only valid if STS TLS is configured

	usersSysType UsersSysType

	rolesMap map[arn.ARN]string

	// Persistence layer for IAM subsystem

		providerPrefix, _, found := strings.Cut(credentials.ParentUser, getKeySeparator())
		if found {
			return providerPrefix // this is true for certificate and custom providers
		}
		return madmin.OpenIDProvider // openid users are already hashed, so no separator
	}

	return madmin.BuiltinProvider // default to internal
}

// getProviderInfoFromClaims - returns the provider info from the claims.

	}

	// Configure an OpenID Connect aware OAuth2 client.
	oauth2Config := oauth2.Config{
		ClientID:     pro.ClientID,
		ClientSecret: pro.ClientSecret,
		RedirectURL:  pro.RedirectURL,

		// Discovery returns the OAuth2 endpoints.
		Endpoint: provider.Endpoint(),

		// "openid" is a required scope for OpenID Connect flows.
		Scopes: []string{oidc.ScopeOpenID, "groups"},
	}

## Introduction

MinIO provides a custom STS API that allows authentication with client X.509 / TLS certificates.

A major advantage of certificate-based authentication compared to other STS authentication methods, like OpenID Connect or LDAP/AD, is that client authentication works without any additional/external component that must be constantly available. Therefore, certificate-based authentication may provide better availability / lower operational complexity.

</AssumeRoleWithClientGrantsResponse>
```

## Using ClientGrants API

```
export MINIO_ROOT_USER=minio
export MINIO_ROOT_PASSWORD=minio123
export MINIO_IDENTITY_OPENID_CONFIG_URL=http://localhost:8080/auth/realms/demo/.well-known/openid-configuration
export MINIO_IDENTITY_OPENID_CLIENT_ID="843351d4-1080-11ea-aa20-271ecba3924a"
minio server /mnt/export
```

Testing with an example