internal/resources/providers/azurelib/auth/auth_provider.go

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// the Apache License, Version 2.0 (the "License"); you may
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//
//     http://www.apache.org/licenses/LICENSE-2.0
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// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

package auth

import (
	"fmt"
	"os"

	"github.com/Azure/azure-sdk-for-go/sdk/azidentity"
)

type AzureAuthProvider struct{}

type AzureAuthProviderAPI interface {
	FindDefaultCredentials(options *azidentity.DefaultAzureCredentialOptions) (*azidentity.DefaultAzureCredential, error)
	FindClientSecretCredentials(tenantID string, clientID string, clientSecret string, options *azidentity.ClientSecretCredentialOptions) (*azidentity.ClientSecretCredential, error)
	FindCertificateCredential(tenantID string, clientID string, certPath string, password string, options *azidentity.ClientCertificateCredentialOptions) (*azidentity.ClientCertificateCredential, error)
}

// FindDefaultCredentials is a wrapper around azidentity.NewDefaultAzureCredential to make it easier to mock
func (a *AzureAuthProvider) FindDefaultCredentials(options *azidentity.DefaultAzureCredentialOptions) (*azidentity.DefaultAzureCredential, error) {
	return azidentity.NewDefaultAzureCredential(options)
}

// FindClientSecretCredentials is a wrapper around azidentity.NewClientSecretCredential to make it easier to mock
func (a *AzureAuthProvider) FindClientSecretCredentials(tenantID string, clientID string, clientSecret string, options *azidentity.ClientSecretCredentialOptions) (*azidentity.ClientSecretCredential, error) {
	return azidentity.NewClientSecretCredential(tenantID, clientID, clientSecret, options)
}

// FindCertificateCredential is a wrapper around azidentity.NewClientCertificateCredential and azidentity.ParseCertificates that loads certificates and a private key, in PEM or PKCS12 format.
func (a *AzureAuthProvider) FindCertificateCredential(tenantID string, clientID string, certPath string, password string, options *azidentity.ClientCertificateCredentialOptions) (*azidentity.ClientCertificateCredential, error) {
	certData, err := os.ReadFile(certPath)
	if err != nil {
		return nil, fmt.Errorf("error trying to read certificate file %s: %s", certPath, err.Error())
	}

	// ParseCertificates requires nil password if the private key isn't encrypted. It can't decrypt keys in PEM format.
	var pwd []byte
	if len(password) > 0 {
		pwd = []byte(password)
	}
	certs, key, err := azidentity.ParseCertificates(certData, pwd)
	if err != nil {
		return nil, fmt.Errorf("error trying to load certificate from %s: %s", certPath, err.Error())
	}

	return azidentity.NewClientCertificateCredential(tenantID, clientID, certs, key, options)
}