boulder/ratelimits/bucket.go

554 lines
20 KiB
Go

package ratelimits
import (
"errors"
"fmt"
"net"
"strconv"
"strings"
"github.com/letsencrypt/boulder/core"
)
// ErrInvalidCost indicates that the cost specified was < 0.
var ErrInvalidCost = fmt.Errorf("invalid cost, must be >= 0")
// ErrInvalidCostOverLimit indicates that the cost specified was > limit.Burst.
var ErrInvalidCostOverLimit = fmt.Errorf("invalid cost, must be <= limit.Burst")
// newIPAddressBucketKey validates and returns a bucketKey for limits that use
// the 'enum:ipAddress' bucket key format.
func newIPAddressBucketKey(name Name, ip net.IP) (string, error) { //nolint: unparam
id := ip.String()
err := validateIdForName(name, id)
if err != nil {
return "", err
}
return joinWithColon(name.EnumString(), id), nil
}
// newIPv6RangeCIDRBucketKey validates and returns a bucketKey for limits that
// use the 'enum:ipv6RangeCIDR' bucket key format.
func newIPv6RangeCIDRBucketKey(name Name, ip net.IP) (string, error) {
if ip.To4() != nil {
return "", fmt.Errorf("invalid IPv6 address, %q must be an IPv6 address", ip.String())
}
ipMask := net.CIDRMask(48, 128)
ipNet := &net.IPNet{IP: ip.Mask(ipMask), Mask: ipMask}
id := ipNet.String()
err := validateIdForName(name, id)
if err != nil {
return "", err
}
return joinWithColon(name.EnumString(), id), nil
}
// newRegIdBucketKey validates and returns a bucketKey for limits that use the
// 'enum:regId' bucket key format.
func newRegIdBucketKey(name Name, regId int64) (string, error) {
id := strconv.FormatInt(regId, 10)
err := validateIdForName(name, id)
if err != nil {
return "", err
}
return joinWithColon(name.EnumString(), id), nil
}
// newDomainBucketKey validates and returns a bucketKey for limits that use the
// 'enum:domain' bucket key format.
func newDomainBucketKey(name Name, orderName string) (string, error) {
err := validateIdForName(name, orderName)
if err != nil {
return "", err
}
return joinWithColon(name.EnumString(), orderName), nil
}
// newRegIdDomainBucketKey validates and returns a bucketKey for limits that use
// the 'enum:regId:domain' bucket key format.
func newRegIdDomainBucketKey(name Name, regId int64, orderName string) (string, error) {
regIdStr := strconv.FormatInt(regId, 10)
err := validateIdForName(name, joinWithColon(regIdStr, orderName))
if err != nil {
return "", err
}
return joinWithColon(name.EnumString(), regIdStr, orderName), nil
}
// newFQDNSetBucketKey validates and returns a bucketKey for limits that use the
// 'enum:fqdnSet' bucket key format.
func newFQDNSetBucketKey(name Name, orderNames []string) (string, error) { //nolint: unparam
err := validateIdForName(name, strings.Join(orderNames, ","))
if err != nil {
return "", err
}
id := fmt.Sprintf("%x", core.HashNames(orderNames))
return joinWithColon(name.EnumString(), id), nil
}
// Transaction represents a single rate limit operation. It includes a
// bucketKey, which combines the specific rate limit enum with a unique
// identifier to form the key where the state of the "bucket" can be referenced
// or stored by the Limiter, the rate limit being enforced, a cost which MUST be
// >= 0, and check/spend fields, which indicate how the Transaction should be
// processed. The following are acceptable combinations of check/spend:
// - check-and-spend: when check and spend are both true, the cost will be
// checked against the bucket's capacity and spent/refunded, when possible.
// - check-only: when only check is true, the cost will be checked against the
// bucket's capacity, but will never be spent/refunded.
// - spend-only: when only spend is true, spending is best-effort. Regardless
// of the bucket's capacity, the transaction will be considered "allowed".
// - allow-only: when neither check nor spend are true, the transaction will
// be considered "allowed" regardless of the bucket's capacity. This is
// useful for limits that are disabled.
type Transaction struct {
bucketKey string
limit limit
cost int64
check bool
spend bool
}
func (txn Transaction) checkOnly() bool {
return txn.check && !txn.spend
}
func (txn Transaction) spendOnly() bool {
return txn.spend && !txn.check
}
func (txn Transaction) allowOnly() bool {
return !txn.check && !txn.spend
}
func validateTransaction(txn Transaction) (Transaction, error) {
if txn.cost < 0 {
return Transaction{}, ErrInvalidCost
}
if txn.cost > txn.limit.Burst {
return Transaction{}, ErrInvalidCostOverLimit
}
return txn, nil
}
func newTransaction(limit limit, bucketKey string, cost int64) (Transaction, error) {
return validateTransaction(Transaction{
bucketKey: bucketKey,
limit: limit,
cost: cost,
check: true,
spend: true,
})
}
func newCheckOnlyTransaction(limit limit, bucketKey string, cost int64) (Transaction, error) {
return validateTransaction(Transaction{
bucketKey: bucketKey,
limit: limit,
cost: cost,
check: true,
})
}
func newSpendOnlyTransaction(limit limit, bucketKey string, cost int64) (Transaction, error) {
return validateTransaction(Transaction{
bucketKey: bucketKey,
limit: limit,
cost: cost,
spend: true,
})
}
func newAllowOnlyTransaction() (Transaction, error) {
// Zero values are sufficient.
return validateTransaction(Transaction{})
}
// TransactionBuilder is used to build Transactions for various rate limits.
// Each rate limit has a corresponding method that returns a Transaction for
// that limit. Call NewTransactionBuilder to create a new *TransactionBuilder.
type TransactionBuilder struct {
*limitRegistry
}
// NewTransactionBuilder returns a new *TransactionBuilder. The provided
// defaults and overrides paths are expected to be paths to YAML files that
// contain the default and override limits, respectively. Overrides is optional,
// defaults is required.
func NewTransactionBuilder(defaults, overrides string) (*TransactionBuilder, error) {
registry, err := newLimitRegistry(defaults, overrides)
if err != nil {
return nil, err
}
return &TransactionBuilder{registry}, nil
}
// registrationsPerIPAddressTransaction returns a Transaction for the
// NewRegistrationsPerIPAddress limit for the provided IP address.
func (builder *TransactionBuilder) registrationsPerIPAddressTransaction(ip net.IP) (Transaction, error) {
bucketKey, err := newIPAddressBucketKey(NewRegistrationsPerIPAddress, ip)
if err != nil {
return Transaction{}, err
}
limit, err := builder.getLimit(NewRegistrationsPerIPAddress, bucketKey)
if err != nil {
if errors.Is(err, errLimitDisabled) {
return newAllowOnlyTransaction()
}
return Transaction{}, err
}
return newTransaction(limit, bucketKey, 1)
}
// registrationsPerIPv6RangeTransaction returns a Transaction for the
// NewRegistrationsPerIPv6Range limit for the /48 IPv6 range which contains the
// provided IPv6 address.
func (builder *TransactionBuilder) registrationsPerIPv6RangeTransaction(ip net.IP) (Transaction, error) {
bucketKey, err := newIPv6RangeCIDRBucketKey(NewRegistrationsPerIPv6Range, ip)
if err != nil {
return Transaction{}, err
}
limit, err := builder.getLimit(NewRegistrationsPerIPv6Range, bucketKey)
if err != nil {
if errors.Is(err, errLimitDisabled) {
return newAllowOnlyTransaction()
}
return Transaction{}, err
}
return newTransaction(limit, bucketKey, 1)
}
// ordersPerAccountTransaction returns a Transaction for the NewOrdersPerAccount
// limit for the provided ACME registration Id.
func (builder *TransactionBuilder) ordersPerAccountTransaction(regId int64) (Transaction, error) {
bucketKey, err := newRegIdBucketKey(NewOrdersPerAccount, regId)
if err != nil {
return Transaction{}, err
}
limit, err := builder.getLimit(NewOrdersPerAccount, bucketKey)
if err != nil {
if errors.Is(err, errLimitDisabled) {
return newAllowOnlyTransaction()
}
return Transaction{}, err
}
return newTransaction(limit, bucketKey, 1)
}
// FailedAuthorizationsPerDomainPerAccountCheckOnlyTransactions returns a slice
// of Transactions for the provided order domain names. An error is returned if
// any of the order domain names are invalid. This method should be used for
// checking capacity, before allowing more authorizations to be created.
//
// Precondition: len(orderDomains) < maxNames.
func (builder *TransactionBuilder) FailedAuthorizationsPerDomainPerAccountCheckOnlyTransactions(regId int64, orderDomains []string) ([]Transaction, error) {
// FailedAuthorizationsPerDomainPerAccount limit uses the 'enum:regId'
// bucket key format for overrides.
perAccountBucketKey, err := newRegIdBucketKey(FailedAuthorizationsPerDomainPerAccount, regId)
if err != nil {
return nil, err
}
limit, err := builder.getLimit(FailedAuthorizationsPerDomainPerAccount, perAccountBucketKey)
if err != nil && !errors.Is(err, errLimitDisabled) {
return nil, err
}
var txns []Transaction
for _, name := range orderDomains {
// FailedAuthorizationsPerDomainPerAccount limit uses the
// 'enum:regId:domain' bucket key format for transactions.
perDomainPerAccountBucketKey, err := newRegIdDomainBucketKey(FailedAuthorizationsPerDomainPerAccount, regId, name)
if err != nil {
return nil, err
}
// Add a check-only transaction for each per domain per account bucket.
// The cost is 0, as we are only checking that the account and domain
// pair aren't already over the limit.
txn, err := newCheckOnlyTransaction(limit, perDomainPerAccountBucketKey, 1)
if err != nil {
return nil, err
}
txns = append(txns, txn)
}
return txns, nil
}
// FailedAuthorizationsPerDomainPerAccountSpendOnlyTransaction returns a spend-
// only Transaction for the provided order domain name. An error is returned if
// the order domain name is invalid. This method should be used for spending
// capacity, as a result of a failed authorization.
func (builder *TransactionBuilder) FailedAuthorizationsPerDomainPerAccountSpendOnlyTransaction(regId int64, orderDomain string) (Transaction, error) {
// FailedAuthorizationsPerDomainPerAccount limit uses the 'enum:regId'
// bucket key format for overrides.
perAccountBucketKey, err := newRegIdBucketKey(FailedAuthorizationsPerDomainPerAccount, regId)
if err != nil {
return Transaction{}, err
}
limit, err := builder.getLimit(FailedAuthorizationsPerDomainPerAccount, perAccountBucketKey)
if err != nil && !errors.Is(err, errLimitDisabled) {
return Transaction{}, err
}
// FailedAuthorizationsPerDomainPerAccount limit uses the
// 'enum:regId:domain' bucket key format for transactions.
perDomainPerAccountBucketKey, err := newRegIdDomainBucketKey(FailedAuthorizationsPerDomainPerAccount, regId, orderDomain)
if err != nil {
return Transaction{}, err
}
txn, err := newSpendOnlyTransaction(limit, perDomainPerAccountBucketKey, 1)
if err != nil {
return Transaction{}, err
}
return txn, nil
}
// certificatesPerDomainCheckOnlyTransactions returns a slice of Transactions
// for the provided order domain names. An error is returned if any of the order
// domain names are invalid. This method should be used for checking capacity,
// before allowing more orders to be created. If a CertificatesPerDomainPerAccount
// override is active, a check-only Transaction is created for each per account
// per domain bucket. Otherwise, a check-only Transaction is generated for each
// global per domain bucket. This method should be used for checking capacity,
// before allowing more orders to be created.
//
// Precondition: All orderDomains must comply with policy.WellFormedDomainNames.
func (builder *TransactionBuilder) certificatesPerDomainCheckOnlyTransactions(regId int64, orderDomains []string) ([]Transaction, error) {
perAccountLimitBucketKey, err := newRegIdBucketKey(CertificatesPerDomainPerAccount, regId)
if err != nil {
return nil, err
}
perAccountLimit, err := builder.getLimit(CertificatesPerDomainPerAccount, perAccountLimitBucketKey)
if err != nil && !errors.Is(err, errLimitDisabled) {
return nil, err
}
var txns []Transaction
for _, name := range FQDNsToETLDsPlusOne(orderDomains) {
perDomainBucketKey, err := newDomainBucketKey(CertificatesPerDomain, name)
if err != nil {
return nil, err
}
if perAccountLimit.isOverride() {
// An override is configured for the CertificatesPerDomainPerAccount
// limit.
perAccountPerDomainKey, err := newRegIdDomainBucketKey(CertificatesPerDomainPerAccount, regId, name)
if err != nil {
return nil, err
}
// Add a check-only transaction for each per account per domain
// bucket.
txn, err := newCheckOnlyTransaction(perAccountLimit, perAccountPerDomainKey, 1)
if err != nil {
return nil, err
}
txns = append(txns, txn)
} else {
// Use the per domain bucket key when no per account per domain override
// is configured.
perDomainLimit, err := builder.getLimit(CertificatesPerDomain, perDomainBucketKey)
if errors.Is(err, errLimitDisabled) {
// Skip disabled limit.
continue
}
if err != nil {
return nil, err
}
// Add a check-only transaction for each per domain bucket.
txn, err := newCheckOnlyTransaction(perDomainLimit, perDomainBucketKey, 1)
if err != nil {
return nil, err
}
txns = append(txns, txn)
}
}
return txns, nil
}
// CertificatesPerDomainSpendOnlyTransactions returns a slice of Transactions
// for the specified order domain names. It returns an error if any domain names
// are invalid. If a CertificatesPerDomainPerAccount override is configured, it
// generates two types of Transactions:
// - A spend-only Transaction for each per-account, per-domain bucket, which
// enforces the limit on certificates issued per domain for each account.
// - A spend-only Transaction for each per-domain bucket, which enforces the
// global limit on certificates issued per domain.
//
// If no CertificatesPerDomainPerAccount override is present, it returns a
// spend-only Transaction for each global per-domain bucket. This method should
// be used for spending capacity, when a certificate is issued.
//
// Precondition: orderDomains must all pass policy.WellFormedDomainNames.
func (builder *TransactionBuilder) CertificatesPerDomainSpendOnlyTransactions(regId int64, orderDomains []string) ([]Transaction, error) {
perAccountLimitBucketKey, err := newRegIdBucketKey(CertificatesPerDomainPerAccount, regId)
if err != nil {
return nil, err
}
perAccountLimit, err := builder.getLimit(CertificatesPerDomainPerAccount, perAccountLimitBucketKey)
if err != nil && !errors.Is(err, errLimitDisabled) {
return nil, err
}
var txns []Transaction
for _, name := range FQDNsToETLDsPlusOne(orderDomains) {
perDomainBucketKey, err := newDomainBucketKey(CertificatesPerDomain, name)
if err != nil {
return nil, err
}
if perAccountLimit.isOverride() {
// An override is configured for the CertificatesPerDomainPerAccount
// limit.
perAccountPerDomainKey, err := newRegIdDomainBucketKey(CertificatesPerDomainPerAccount, regId, name)
if err != nil {
return nil, err
}
// Add a spend-only transaction for each per account per domain
// bucket.
txn, err := newSpendOnlyTransaction(perAccountLimit, perAccountPerDomainKey, 1)
if err != nil {
return nil, err
}
txns = append(txns, txn)
perDomainLimit, err := builder.getLimit(CertificatesPerDomain, perDomainBucketKey)
if errors.Is(err, errLimitDisabled) {
// Skip disabled limit.
continue
}
if err != nil {
return nil, err
}
// Add a spend-only transaction for each per domain bucket.
txn, err = newSpendOnlyTransaction(perDomainLimit, perDomainBucketKey, 1)
if err != nil {
return nil, err
}
txns = append(txns, txn)
} else {
// Use the per domain bucket key when no per account per domain
// override is configured.
perDomainLimit, err := builder.getLimit(CertificatesPerDomain, perDomainBucketKey)
if errors.Is(err, errLimitDisabled) {
// Skip disabled limit.
continue
}
if err != nil {
return nil, err
}
// Add a spend-only transaction for each per domain bucket.
txn, err := newSpendOnlyTransaction(perDomainLimit, perDomainBucketKey, 1)
if err != nil {
return nil, err
}
txns = append(txns, txn)
}
}
return txns, nil
}
// certificatesPerFQDNSetCheckOnlyTransaction returns a check-only Transaction
// for the provided order domain names. This method should only be used for
// checking capacity, before allowing more orders to be created.
func (builder *TransactionBuilder) certificatesPerFQDNSetCheckOnlyTransaction(orderNames []string) (Transaction, error) {
bucketKey, err := newFQDNSetBucketKey(CertificatesPerFQDNSet, orderNames)
if err != nil {
return Transaction{}, err
}
limit, err := builder.getLimit(CertificatesPerFQDNSet, bucketKey)
if err != nil {
if errors.Is(err, errLimitDisabled) {
return newAllowOnlyTransaction()
}
return Transaction{}, err
}
return newCheckOnlyTransaction(limit, bucketKey, 1)
}
// CertificatesPerFQDNSetSpendOnlyTransaction returns a spend-only Transaction
// for the provided order domain names. This method should only be used for
// spending capacity, when a certificate is issued.
func (builder *TransactionBuilder) CertificatesPerFQDNSetSpendOnlyTransaction(orderNames []string) (Transaction, error) {
bucketKey, err := newFQDNSetBucketKey(CertificatesPerFQDNSet, orderNames)
if err != nil {
return Transaction{}, err
}
limit, err := builder.getLimit(CertificatesPerFQDNSet, bucketKey)
if err != nil {
if errors.Is(err, errLimitDisabled) {
return newAllowOnlyTransaction()
}
return Transaction{}, err
}
return newSpendOnlyTransaction(limit, bucketKey, 1)
}
// NewOrderLimitTransactions takes in values from a new-order request and
// returns the set of rate limit transactions that should be evaluated before
// allowing the request to proceed.
//
// Precondition: names must be a list of DNS names that all pass
// policy.WellFormedDomainNames.
func (builder *TransactionBuilder) NewOrderLimitTransactions(regId int64, names []string, isRenewal bool) ([]Transaction, error) {
makeTxnError := func(err error, limit Name) error {
return fmt.Errorf("error constructing rate limit transaction for %s rate limit: %w", limit, err)
}
var transactions []Transaction
if !isRenewal {
txn, err := builder.ordersPerAccountTransaction(regId)
if err != nil {
return nil, makeTxnError(err, NewOrdersPerAccount)
}
transactions = append(transactions, txn)
}
txns, err := builder.FailedAuthorizationsPerDomainPerAccountCheckOnlyTransactions(regId, names)
if err != nil {
return nil, makeTxnError(err, FailedAuthorizationsPerDomainPerAccount)
}
transactions = append(transactions, txns...)
if !isRenewal {
txns, err := builder.certificatesPerDomainCheckOnlyTransactions(regId, names)
if err != nil {
return nil, makeTxnError(err, CertificatesPerDomain)
}
transactions = append(transactions, txns...)
}
txn, err := builder.certificatesPerFQDNSetCheckOnlyTransaction(names)
if err != nil {
return nil, makeTxnError(err, CertificatesPerFQDNSet)
}
return append(transactions, txn), nil
}
// NewAccountLimitTransactions takes in an IP address from a new-account request
// and returns the set of rate limit transactions that should be evaluated
// before allowing the request to proceed.
func (builder *TransactionBuilder) NewAccountLimitTransactions(ip net.IP) ([]Transaction, error) {
makeTxnError := func(err error, limit Name) error {
return fmt.Errorf("error constructing rate limit transaction for %s rate limit: %w", limit, err)
}
var transactions []Transaction
txn, err := builder.registrationsPerIPAddressTransaction(ip)
if err != nil {
return nil, makeTxnError(err, NewRegistrationsPerIPAddress)
}
transactions = append(transactions, txn)
if ip.To4() != nil {
// This request was made from an IPv4 address.
return transactions, nil
}
txn, err = builder.registrationsPerIPv6RangeTransaction(ip)
if err != nil {
return nil, makeTxnError(err, NewRegistrationsPerIPv6Range)
}
return append(transactions, txn), nil
}