resource_kms_crypto_key.go

package google

import (
	"fmt"
	"log"
	"regexp"
	"strconv"
	"strings"
	"time"

	"github.com/hashicorp/terraform/helper/schema"
	"google.golang.org/api/cloudkms/v1"
)

func resourceKmsCryptoKey() *schema.Resource {
	return &schema.Resource{
		Create: resourceKmsCryptoKeyCreate,
		Read:   resourceKmsCryptoKeyRead,
		Delete: resourceKmsCryptoKeyDelete,
		Importer: &schema.ResourceImporter{
			State: schema.ImportStatePassthrough,
		},

		Schema: map[string]*schema.Schema{
			"name": &schema.Schema{
				Type:     schema.TypeString,
				Required: true,
				ForceNew: true,
			},
			"key_ring": &schema.Schema{
				Type:     schema.TypeString,
				Required: true,
				ForceNew: true,
			},
			"rotation_period": &schema.Schema{
				Type:         schema.TypeString,
				Optional:     true,
				ForceNew:     true,
				ValidateFunc: validateKmsCryptoKeyRotationPeriod,
			},
		},
	}
}

type kmsCryptoKeyId struct {
	KeyRingId kmsKeyRingId
	Name      string
}

func (s *kmsCryptoKeyId) cryptoKeyId() string {
	return fmt.Sprintf("%s/cryptoKeys/%s", s.KeyRingId.keyRingId(), s.Name)
}

func (s *kmsCryptoKeyId) parentId() string {
	return s.KeyRingId.keyRingId()
}

func (s *kmsCryptoKeyId) terraformId() string {
	return fmt.Sprintf("%s/%s", s.KeyRingId.terraformId(), s.Name)
}

func resourceKmsCryptoKeyCreate(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)

	keyRingId, err := parseKmsKeyRingId(d.Get("key_ring").(string), config)

	if err != nil {
		return err
	}

	cryptoKeyId := &kmsCryptoKeyId{
		KeyRingId: *keyRingId,
		Name:      d.Get("name").(string),
	}

	key := cloudkms.CryptoKey{Purpose: "ENCRYPT_DECRYPT"}

	if d.Get("rotation_period") != "" {
		rotationPeriod := d.Get("rotation_period").(string)
		nextRotation, err := kmsCryptoKeyNextRotation(time.Now(), rotationPeriod)

		if err != nil {
			return fmt.Errorf("Error setting CryptoKey rotation period: %s", err.Error())
		}

		key.NextRotationTime = nextRotation
		key.RotationPeriod = rotationPeriod
	}

	cryptoKey, err := config.clientKms.Projects.Locations.KeyRings.CryptoKeys.Create(cryptoKeyId.KeyRingId.keyRingId(), &key).CryptoKeyId(cryptoKeyId.Name).Do()

	if err != nil {
		return fmt.Errorf("Error creating CryptoKey: %s", err.Error())
	}

	log.Printf("[DEBUG] Created CryptoKey %s", cryptoKey.Name)

	d.SetId(cryptoKeyId.terraformId())

	return resourceKmsCryptoKeyRead(d, meta)
}

func resourceKmsCryptoKeyRead(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)

	cryptoKeyId, err := parseKmsCryptoKeyId(d.Id(), config)
	if err != nil {
		return err
	}

	log.Printf("[DEBUG] Executing read for KMS CryptoKey %s", cryptoKeyId.cryptoKeyId())

	cryptoKey, err := config.clientKms.Projects.Locations.KeyRings.CryptoKeys.Get(cryptoKeyId.cryptoKeyId()).Do()
	if err != nil {
		return fmt.Errorf("Error reading CryptoKey: %s", err)
	}
	d.Set("key_ring", cryptoKeyId.KeyRingId.terraformId())
	d.Set("name", cryptoKeyId.Name)
	d.Set("rotation_period", cryptoKey.RotationPeriod)

	d.SetId(cryptoKeyId.terraformId())

	return nil
}

func clearCryptoKeyVersions(cryptoKeyId *kmsCryptoKeyId, config *Config) error {
	versionsClient := config.clientKms.Projects.Locations.KeyRings.CryptoKeys.CryptoKeyVersions

	versionsResponse, err := versionsClient.List(cryptoKeyId.cryptoKeyId()).Do()

	if err != nil {
		return err
	}

	for _, version := range versionsResponse.CryptoKeyVersions {
		request := &cloudkms.DestroyCryptoKeyVersionRequest{}
		_, err = versionsClient.Destroy(version.Name, request).Do()

		if err != nil {
			return err
		}
	}

	return nil
}

/*
	Because KMS CryptoKey resources cannot be deleted on GCP, we are only going to remove it from state
	and destroy all its versions, rendering the key useless for encryption and decryption of data.
	Re-creation of this resource through Terraform will produce an error.
*/

func resourceKmsCryptoKeyDelete(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)

	cryptoKeyId, err := parseKmsCryptoKeyId(d.Id(), config)
	if err != nil {
		return err
	}

	log.Printf(`
[WARNING] KMS CryptoKey resources cannot be deleted from GCP. The CryptoKey %s will be removed from Terraform state,
and all its CryptoKeyVersions will be destroyed, but it will still be present on the server.`, cryptoKeyId.cryptoKeyId())

	err = clearCryptoKeyVersions(cryptoKeyId, config)

	if err != nil {
		return err
	}

	d.SetId("")
	return nil
}

func validateKmsCryptoKeyRotationPeriod(value interface{}, _ string) (ws []string, errors []error) {
	period := value.(string)
	pattern := regexp.MustCompile("^([0-9.]*\\d)s$")
	match := pattern.FindStringSubmatch(period)

	if len(match) == 0 {
		errors = append(errors, fmt.Errorf("Invalid rotation period format: %s", period))
		// Cannot continue to validate because we cannot extract a number.
		return
	}

	number := match[1]
	seconds, err := strconv.ParseFloat(number, 64)

	if err != nil {
		errors = append(errors, err)
	} else {
		if seconds < 86400.0 {
			errors = append(errors, fmt.Errorf("Rotation period must be greater than one day"))
		}

		parts := strings.Split(number, ".")

		if len(parts) > 1 && len(parts[1]) > 9 {
			errors = append(errors, fmt.Errorf("Rotation period cannot have more than 9 fractional digits"))
		}
	}

	return
}

func kmsCryptoKeyNextRotation(now time.Time, period string) (result string, err error) {
	var duration time.Duration

	duration, err = time.ParseDuration(period)

	if err == nil {
		result = now.UTC().Add(duration).Format(time.RFC3339Nano)
	}

	return
}

func parseKmsCryptoKeyId(id string, config *Config) (*kmsCryptoKeyId, error) {
	parts := strings.Split(id, "/")

	cryptoKeyIdRegex := regexp.MustCompile("^([a-z0-9-]+)/([a-z0-9-])+/([a-zA-Z0-9_-]{1,63})/([a-zA-Z0-9_-]{1,63})$")
	cryptoKeyIdWithoutProjectRegex := regexp.MustCompile("^([a-z0-9-])+/([a-zA-Z0-9_-]{1,63})/([a-zA-Z0-9_-]{1,63})$")

	if cryptoKeyIdRegex.MatchString(id) {
		return &kmsCryptoKeyId{
			KeyRingId: kmsKeyRingId{
				Project:  parts[0],
				Location: parts[1],
				Name:     parts[2],
			},
			Name: parts[3],
		}, nil
	}

	if cryptoKeyIdWithoutProjectRegex.MatchString(id) {
		if config.Project == "" {
			return nil, fmt.Errorf("The default project for the provider must be set when using the `{location}/{keyRingName}/{cryptoKeyName}` id format.")
		}

		return &kmsCryptoKeyId{
			KeyRingId: kmsKeyRingId{
				Project:  config.Project,
				Location: parts[0],
				Name:     parts[1],
			},
			Name: parts[2],
		}, nil
	}

	return nil, fmt.Errorf("Invalid CryptoKey id format, expecting `{projectId}/{locationId}/{KeyringName}/{cryptoKeyName}` or `{locationId}/{keyRingName}/{cryptoKeyName}.`")
}