boulder/ratelimit/rate-limits.go

238 lines
9.1 KiB
Go

package ratelimit
import (
"strconv"
"time"
"github.com/letsencrypt/boulder/config"
"github.com/letsencrypt/boulder/strictyaml"
)
const (
// CertificatesPerName is the name of the CertificatesPerName rate limit
// when referenced in metric labels.
CertificatesPerName = "certificates_per_domain"
// RegistrationsPerIP is the name of the RegistrationsPerIP rate limit when
// referenced in metric labels.
RegistrationsPerIP = "registrations_per_ip"
// RegistrationsPerIPRange is the name of the RegistrationsPerIPRange rate
// limit when referenced in metric labels.
RegistrationsPerIPRange = "registrations_per_ipv6_range"
// PendingAuthorizationsPerAccount is the name of the
// PendingAuthorizationsPerAccount rate limit when referenced in metric
// labels.
PendingAuthorizationsPerAccount = "pending_authorizations_per_account"
// InvalidAuthorizationsPerAccount is the name of the
// InvalidAuthorizationsPerAccount rate limit when referenced in metric
// labels.
InvalidAuthorizationsPerAccount = "failed_authorizations_per_account"
// CertificatesPerFQDNSet is the name of the CertificatesPerFQDNSet rate
// limit when referenced in metric labels.
CertificatesPerFQDNSet = "certificates_per_fqdn_set"
// CertificatesPerFQDNSetFast is the name of the CertificatesPerFQDNSetFast
// rate limit when referenced in metric labels.
CertificatesPerFQDNSetFast = "certificates_per_fqdn_set_fast"
// NewOrdersPerAccount is the name of the NewOrdersPerAccount rate limit
// when referenced in metric labels.
NewOrdersPerAccount = "new_orders_per_account"
)
// Limits is defined to allow mock implementations be provided during unit
// testing
type Limits interface {
CertificatesPerName() RateLimitPolicy
RegistrationsPerIP() RateLimitPolicy
RegistrationsPerIPRange() RateLimitPolicy
PendingAuthorizationsPerAccount() RateLimitPolicy
InvalidAuthorizationsPerAccount() RateLimitPolicy
CertificatesPerFQDNSet() RateLimitPolicy
CertificatesPerFQDNSetFast() RateLimitPolicy
NewOrdersPerAccount() RateLimitPolicy
LoadPolicies(contents []byte) error
}
// limitsImpl is an unexported implementation of the Limits interface. It acts
// as a container for a rateLimitConfig.
type limitsImpl struct {
rlPolicy *rateLimitConfig
}
func (r *limitsImpl) CertificatesPerName() RateLimitPolicy {
if r.rlPolicy == nil {
return RateLimitPolicy{}
}
return r.rlPolicy.CertificatesPerName
}
func (r *limitsImpl) RegistrationsPerIP() RateLimitPolicy {
if r.rlPolicy == nil {
return RateLimitPolicy{}
}
return r.rlPolicy.RegistrationsPerIP
}
func (r *limitsImpl) RegistrationsPerIPRange() RateLimitPolicy {
if r.rlPolicy == nil {
return RateLimitPolicy{}
}
return r.rlPolicy.RegistrationsPerIPRange
}
func (r *limitsImpl) PendingAuthorizationsPerAccount() RateLimitPolicy {
if r.rlPolicy == nil {
return RateLimitPolicy{}
}
return r.rlPolicy.PendingAuthorizationsPerAccount
}
func (r *limitsImpl) InvalidAuthorizationsPerAccount() RateLimitPolicy {
if r.rlPolicy == nil {
return RateLimitPolicy{}
}
return r.rlPolicy.InvalidAuthorizationsPerAccount
}
func (r *limitsImpl) CertificatesPerFQDNSet() RateLimitPolicy {
if r.rlPolicy == nil {
return RateLimitPolicy{}
}
return r.rlPolicy.CertificatesPerFQDNSet
}
func (r *limitsImpl) CertificatesPerFQDNSetFast() RateLimitPolicy {
if r.rlPolicy == nil {
return RateLimitPolicy{}
}
return r.rlPolicy.CertificatesPerFQDNSetFast
}
func (r *limitsImpl) NewOrdersPerAccount() RateLimitPolicy {
if r.rlPolicy == nil {
return RateLimitPolicy{}
}
return r.rlPolicy.NewOrdersPerAccount
}
// LoadPolicies loads various rate limiting policies from a byte array of
// YAML configuration.
func (r *limitsImpl) LoadPolicies(contents []byte) error {
var newPolicy rateLimitConfig
err := strictyaml.Unmarshal(contents, &newPolicy)
if err != nil {
return err
}
r.rlPolicy = &newPolicy
return nil
}
func New() Limits {
return &limitsImpl{}
}
// rateLimitConfig contains all application layer rate limiting policies. It is
// unexported and clients are expected to use the exported container struct
type rateLimitConfig struct {
// Number of certificates that can be extant containing any given name.
// These are counted by "base domain" aka eTLD+1, so any entries in the
// overrides section must be an eTLD+1 according to the publicsuffix package.
CertificatesPerName RateLimitPolicy `yaml:"certificatesPerName"`
// Number of registrations that can be created per IP.
// Note: Since this is checked before a registration is created, setting a
// RegistrationOverride on it has no effect.
RegistrationsPerIP RateLimitPolicy `yaml:"registrationsPerIP"`
// Number of registrations that can be created per fuzzy IP range. Unlike
// RegistrationsPerIP this will apply to a /48 for IPv6 addresses to help curb
// abuse from easily obtained IPv6 ranges.
// Note: Like RegistrationsPerIP, setting a RegistrationOverride has no
// effect here.
RegistrationsPerIPRange RateLimitPolicy `yaml:"registrationsPerIPRange"`
// Number of pending authorizations that can exist per account. Overrides by
// key are not applied, but overrides by registration are.
PendingAuthorizationsPerAccount RateLimitPolicy `yaml:"pendingAuthorizationsPerAccount"`
// Number of invalid authorizations that can be failed per account within the
// given window. Overrides by key are not applied, but overrides by registration are.
// Note that this limit is actually "per account, per hostname," but that
// is too long for the variable name.
InvalidAuthorizationsPerAccount RateLimitPolicy `yaml:"invalidAuthorizationsPerAccount"`
// Number of new orders that can be created per account within the given
// window. Overrides by key are not applied, but overrides by registration are.
NewOrdersPerAccount RateLimitPolicy `yaml:"newOrdersPerAccount"`
// Number of certificates that can be extant containing a specific set
// of DNS names.
CertificatesPerFQDNSet RateLimitPolicy `yaml:"certificatesPerFQDNSet"`
// Same as above, but intended to both trigger and reset faster (i.e. a
// lower threshold and smaller window), so that clients don't have to wait
// a long time after a small burst of accidental duplicate issuance.
CertificatesPerFQDNSetFast RateLimitPolicy `yaml:"certificatesPerFQDNSetFast"`
}
// RateLimitPolicy describes a general limiting policy
type RateLimitPolicy struct {
// How long to count items for
Window config.Duration `yaml:"window"`
// The max number of items that can be present before triggering the rate
// limit. Zero means "no limit."
Threshold int64 `yaml:"threshold"`
// A per-key override setting different limits than the default (higher or lower).
// The key is defined on a per-limit basis and should match the key it counts on.
// For instance, a rate limit on the number of certificates per name uses name as
// a key, while a rate limit on the number of registrations per IP subnet would
// use subnet as a key. Note that a zero entry in the overrides map does not
// mean "no limit," it means a limit of zero. An entry of -1 means
// "no limit", only for the pending authorizations rate limit.
Overrides map[string]int64 `yaml:"overrides"`
// A per-registration override setting. This can be used, e.g. if there are
// hosting providers that we would like to grant a higher rate of issuance
// than the default. If both key-based and registration-based overrides are
// available, whichever is larger takes priority. Note that a zero entry in
// the overrides map does not mean "no limit", it means a limit of zero.
RegistrationOverrides map[int64]int64 `yaml:"registrationOverrides"`
}
// Enabled returns true iff the RateLimitPolicy is enabled.
func (rlp *RateLimitPolicy) Enabled() bool {
return rlp.Threshold != 0
}
// GetThreshold returns the threshold for this rate limit and the override
// Id/Key if that threshold is the result of an override for the default limit,
// empty-string otherwise. The threshold returned takes into account any
// overrides for `key` or `regID`. If both `key` and `regID` have an override
// the largest of the two will be used.
func (rlp *RateLimitPolicy) GetThreshold(key string, regID int64) (int64, string) {
regOverride, regOverrideExists := rlp.RegistrationOverrides[regID]
keyOverride, keyOverrideExists := rlp.Overrides[key]
if regOverrideExists && !keyOverrideExists {
// If there is a regOverride and no keyOverride use the regOverride
return regOverride, strconv.FormatInt(regID, 10)
} else if !regOverrideExists && keyOverrideExists {
// If there is a keyOverride and no regOverride use the keyOverride
return keyOverride, key
} else if regOverrideExists && keyOverrideExists {
// If there is both a regOverride and a keyOverride use whichever is larger.
if regOverride > keyOverride {
return regOverride, strconv.FormatInt(regID, 10)
} else {
return keyOverride, key
}
}
// Otherwise there was no regOverride and no keyOverride, use the base
// Threshold
return rlp.Threshold, ""
}
// WindowBegin returns the time that a RateLimitPolicy's window begins, given a
// particular end time (typically the current time).
func (rlp *RateLimitPolicy) WindowBegin(windowEnd time.Time) time.Time {
return windowEnd.Add(-1 * rlp.Window.Duration)
}