open-consul/agent/structs/connect_ca.go

542 lines
18 KiB
Go

package structs
import (
"fmt"
"reflect"
"time"
"github.com/hashicorp/consul/lib"
"github.com/mitchellh/mapstructure"
)
const (
DefaultCARotationPeriod = "2160h"
DefaultLeafCertTTL = "72h"
DefaultIntermediateCertTTL = "8760h" // 365 * 24h
)
// IndexedCARoots is the list of currently trusted CA Roots.
type IndexedCARoots struct {
// ActiveRootID is the ID of a root in Roots that is the active CA root.
// Other roots are still valid if they're in the Roots list but are in
// the process of being rotated out.
ActiveRootID string
// TrustDomain is the identification root for this Consul cluster. All
// certificates signed by the cluster's CA must have their identifying URI in
// this domain.
//
// This does not include the protocol (currently spiffe://) since we may
// implement other protocols in future with equivalent semantics. It should be
// compared against the "authority" section of a URI (i.e. host:port).
//
// We need to support migrating a cluster between trust domains to support
// Multi-DC migration in Enterprise. In this case the current trust domain is
// here but entries in Roots may also have ExternalTrustDomain set to a
// non-empty value implying they were previous roots that are still trusted
// but under a different trust domain.
//
// Note that we DON'T validate trust domain during AuthZ since it causes
// issues of loss of connectivity during migration between trust domains. The
// only time the additional validation adds value is where the cluster shares
// an external root (e.g. organization-wide root) with another distinct Consul
// cluster or PKI system. In this case, x509 Name Constraints can be added to
// enforce that Consul's CA can only validly sign or trust certs within the
// same trust-domain. Name constraints as enforced by TLS handshake also allow
// seamless rotation between trust domains thanks to cross-signing.
TrustDomain string
// Roots is a list of root CA certs to trust.
Roots []*CARoot
// QueryMeta contains the meta sent via a header. We ignore for JSON
// so this whole structure can be returned.
QueryMeta `json:"-"`
}
// CARoot represents a root CA certificate that is trusted.
type CARoot struct {
// ID is a globally unique ID (UUID) representing this CA root.
ID string
// Name is a human-friendly name for this CA root. This value is
// opaque to Consul and is not used for anything internally.
Name string
// SerialNumber is the x509 serial number of the certificate.
SerialNumber uint64
// SigningKeyID is the ID of the public key that corresponds to the private
// key used to sign leaf certificates. Is is the HexString format of the
// raw AuthorityKeyID bytes.
SigningKeyID string
// ExternalTrustDomain is the trust domain this root was generated under. It
// is usually empty implying "the current cluster trust-domain". It is set
// only in the case that a cluster changes trust domain and then all old roots
// that are still trusted have the old trust domain set here.
//
// We currently DON'T validate these trust domains explicitly anywhere, see
// IndexedRoots.TrustDomain doc. We retain this information for debugging and
// future flexibility.
ExternalTrustDomain string
// Time validity bounds.
NotBefore time.Time
NotAfter time.Time
// RootCert is the PEM-encoded public certificate.
RootCert string
// IntermediateCerts is a list of PEM-encoded intermediate certs to
// attach to any leaf certs signed by this CA.
IntermediateCerts []string
// SigningCert is the PEM-encoded signing certificate and SigningKey
// is the PEM-encoded private key for the signing certificate. These
// may actually be empty if the CA plugin in use manages these for us.
SigningCert string `json:",omitempty"`
SigningKey string `json:",omitempty"`
// Active is true if this is the current active CA. This must only
// be true for exactly one CA. For any method that modifies roots in the
// state store, tests should be written to verify that multiple roots
// cannot be active.
Active bool
// RotatedOutAt is the time at which this CA was removed from the state.
// This will only be set on roots that have been rotated out from being the
// active root.
RotatedOutAt time.Time `json:"-"`
// PrivateKeyType is the type of the private key used to sign certificates. It
// may be "rsa" or "ec". This is provided as a convenience to avoid parsing
// the public key to from the certificate to infer the type.
PrivateKeyType string
// PrivateKeyBits is the length of the private key used to sign certificates.
// This is provided as a convenience to avoid parsing the public key from the
// certificate to infer the type.
PrivateKeyBits int
RaftIndex
}
// CARoots is a list of CARoot structures.
type CARoots []*CARoot
// CASignRequest is the request for signing a service certificate.
type CASignRequest struct {
// Datacenter is the target for this request.
Datacenter string
// CSR is the PEM-encoded CSR.
CSR string
// WriteRequest is a common struct containing ACL tokens and other
// write-related common elements for requests.
WriteRequest
}
// RequestDatacenter returns the datacenter for a given request.
func (q *CASignRequest) RequestDatacenter() string {
return q.Datacenter
}
// IssuedCert is a certificate that has been issued by a Connect CA.
type IssuedCert struct {
// SerialNumber is the unique serial number for this certificate.
// This is encoded in standard hex separated by :.
SerialNumber string
// CertPEM and PrivateKeyPEM are the PEM-encoded certificate and private
// key for that cert, respectively. This should not be stored in the
// state store, but is present in the sign API response.
CertPEM string `json:",omitempty"`
PrivateKeyPEM string `json:",omitempty"`
// Service is the name of the service for which the cert was issued.
// ServiceURI is the cert URI value.
Service string `json:",omitempty"`
ServiceURI string `json:",omitempty"`
// Agent is the name of the node for which the cert was issued.
// AgentURI is the cert URI value.
Agent string `json:",omitempty"`
AgentURI string `json:",omitempty"`
// ValidAfter and ValidBefore are the validity periods for the
// certificate.
ValidAfter time.Time
ValidBefore time.Time
// EnterpriseMeta is the Consul Enterprise specific metadata
EnterpriseMeta
RaftIndex
}
// CAOp is the operation for a request related to intentions.
type CAOp string
const (
CAOpSetRoots CAOp = "set-roots"
CAOpSetConfig CAOp = "set-config"
CAOpSetProviderState CAOp = "set-provider-state"
CAOpDeleteProviderState CAOp = "delete-provider-state"
CAOpSetRootsAndConfig CAOp = "set-roots-config"
CAOpIncrementProviderSerialNumber CAOp = "increment-provider-serial"
)
// CARequest is used to modify connect CA data. This is used by the
// FSM (agent/consul/fsm) to apply changes.
type CARequest struct {
// Op is the type of operation being requested. This determines what
// other fields are required.
Op CAOp
// Datacenter is the target for this request.
Datacenter string
// Index is used by CAOpSetRoots and CAOpSetConfig for a CAS operation.
Index uint64
// Roots is a list of roots. This is used for CAOpSet. One root must
// always be active.
Roots []*CARoot
// Config is the configuration for the current CA plugin.
Config *CAConfiguration
// ProviderState is the state for the builtin CA provider.
ProviderState *CAConsulProviderState
// WriteRequest is a common struct containing ACL tokens and other
// write-related common elements for requests.
WriteRequest
}
// RequestDatacenter returns the datacenter for a given request.
func (q *CARequest) RequestDatacenter() string {
return q.Datacenter
}
const (
ConsulCAProvider = "consul"
VaultCAProvider = "vault"
AWSCAProvider = "aws-pca"
)
// CAConfiguration is the configuration for the current CA plugin.
type CAConfiguration struct {
// ClusterID is a unique identifier for the cluster
ClusterID string `json:"-"`
// Provider is the CA provider implementation to use.
Provider string
// Configuration is arbitrary configuration for the provider. This
// should only contain primitive values and containers (such as lists
// and maps).
Config map[string]interface{}
// State is optionally used by the provider to persist information it needs
// between reloads like UUIDs of resources it manages. It only supports string
// values to avoid gotchas with interface{} since this is encoded through
// msgpack when it's written through raft. For example if providers used a
// custom struct or even a simple `int` type, msgpack with loose type
// information during encode/decode and providers will end up getting back
// different types have have to remember to test multiple variants of state
// handling to account for cases where it's been through msgpack or not.
// Keeping this as strings only forces compatibility and leaves the input
// Providers have to work with unambiguous - they can parse ints or other
// types as they need. We expect this only to be used to store a handful of
// identifiers anyway so this is simpler.
State map[string]string
// ForceWithoutCrossSigning indicates that the CA reconfiguration should go
// ahead even if the current CA is unable to cross sign certificates. This
// risks temporary connection failures during the rollout as new leafs will be
// rejected by proxies that have not yet observed the new root cert but is the
// only option if a CA that doesn't support cross signing needs to be
// reconfigured or mirated away from.
ForceWithoutCrossSigning bool
RaftIndex
}
func (c *CAConfiguration) UnmarshalJSON(data []byte) (err error) {
type Alias CAConfiguration
aux := &struct {
ForceWithoutCrossSigningSnake bool `json:"force_without_cross_signing"`
*Alias
}{
Alias: (*Alias)(c),
}
if err = lib.UnmarshalJSON(data, &aux); err != nil {
return err
}
if aux.ForceWithoutCrossSigningSnake {
c.ForceWithoutCrossSigning = aux.ForceWithoutCrossSigningSnake
}
return nil
}
func (c *CAConfiguration) GetCommonConfig() (*CommonCAProviderConfig, error) {
if c == nil {
return nil, fmt.Errorf("config map was nil")
}
var config CommonCAProviderConfig
// Set Defaults
config.CSRMaxPerSecond = 50 // See doc comment for rationale here.
decodeConf := &mapstructure.DecoderConfig{
DecodeHook: ParseDurationFunc(),
Result: &config,
WeaklyTypedInput: true,
}
decoder, err := mapstructure.NewDecoder(decodeConf)
if err != nil {
return nil, err
}
if err := decoder.Decode(c.Config); err != nil {
return nil, fmt.Errorf("error decoding config: %s", err)
}
return &config, nil
}
type CommonCAProviderConfig struct {
LeafCertTTL time.Duration
SkipValidate bool
// CSRMaxPerSecond is a rate limit on processing Connect Certificate Signing
// Requests on the servers. It applies to all CA providers so can be used to
// limit rate to an external CA too. 0 disables the rate limit. Defaults to 50
// which is low enough to prevent overload of a reasonably sized production
// server while allowing a cluster with 1000 service instances to complete a
// rotation in 20 seconds. For reference a quad-core 2017 MacBook pro can
// process 100 signing RPCs a second while using less than half of one core.
// For large clusters with powerful servers it's advisable to increase this
// rate or to disable this limit and instead rely on CSRMaxConcurrent to only
// consume a subset of the server's cores.
CSRMaxPerSecond float32
// CSRMaxConcurrent is a limit on how many concurrent CSR signing requests
// will be processed in parallel. New incoming signing requests will try for
// `consul.csrSemaphoreWait` (currently 500ms) for a slot before being
// rejected with a "rate limited" backpressure response. This effectively sets
// how many CPU cores can be occupied by Connect CA signing activity and
// should be a (small) subset of your server's available cores to allow other
// tasks to complete when a barrage of CSRs come in (e.g. after a CA root
// rotation). Setting to 0 disables the limit, attempting to sign certs
// immediately in the RPC goroutine. This is 0 by default and CSRMaxPerSecond
// is used. This is ignored if CSRMaxPerSecond is non-zero.
CSRMaxConcurrent int
// PrivateKeyType specifies which type of key the CA should generate. It only
// applies when the provider is generating its own key and is ignored if the
// provider already has a key or an external key is provided. Supported values
// are "ec" or "rsa". "ec" is the default and will generate a NIST P-256
// Elliptic key.
PrivateKeyType string
// PrivateKeyBits specifies the number of bits the CA's private key should
// use. For RSA, supported values are 2048 and 4096. For EC, supported values
// are 224, 256, 384 and 521 and correspond to the NIST P-* curve of the same
// name. As with PrivateKeyType this is only relevant whan the provier is
// generating new CA keys (root or intermediate).
PrivateKeyBits int
}
var MinLeafCertTTL = time.Hour
var MaxLeafCertTTL = 365 * 24 * time.Hour
func (c CommonCAProviderConfig) Validate() error {
if c.SkipValidate {
return nil
}
if c.LeafCertTTL < MinLeafCertTTL {
return fmt.Errorf("leaf cert TTL must be greater or equal than %s", MinLeafCertTTL)
}
if c.LeafCertTTL > MaxLeafCertTTL {
return fmt.Errorf("leaf cert TTL must be less than %s", MaxLeafCertTTL)
}
switch c.PrivateKeyType {
case "ec":
if c.PrivateKeyBits != 224 && c.PrivateKeyBits != 256 && c.PrivateKeyBits != 384 && c.PrivateKeyBits != 521 {
return fmt.Errorf("EC key length must be one of (224, 256, 384, 521) bits")
}
case "rsa":
if c.PrivateKeyBits != 2048 && c.PrivateKeyBits != 4096 {
return fmt.Errorf("RSA key length must be 2048 or 4096 bits")
}
default:
return fmt.Errorf("private key type must be either 'ec' or 'rsa'")
}
return nil
}
type ConsulCAProviderConfig struct {
CommonCAProviderConfig `mapstructure:",squash"`
PrivateKey string
RootCert string
RotationPeriod time.Duration
IntermediateCertTTL time.Duration
// DisableCrossSigning is really only useful in test code to use the built in
// provider while exercising logic that depends on the CA provider ability to
// cross sign. We don't document this config field publicly or make any
// attempt to parse it from snake case unlike other fields here.
DisableCrossSigning bool
}
// intermediateCertRenewInterval is the interval at which the expiration
// of the intermediate cert is checked and renewed if necessary.
var IntermediateCertRenewInterval = time.Hour
func (c *ConsulCAProviderConfig) Validate() error {
if c.IntermediateCertTTL < (3 * IntermediateCertRenewInterval) {
// Intermediate Certificates are checked every
// hour(intermediateCertRenewInterval) if they are about to
// expire. Recreating an intermediate certs is started once
// more than half its lifetime has passed.
// If it would be 2h, worst case is that the check happens
// right before half time and when the check happens again, the
// certificate is very close to expiring, leaving only a small
// timeframe to renew. 3h leaves more than 30min to recreate.
// Right now the minimum LeafCertTTL is 1h, which means this
// check not strictly needed, because the same thing is covered
// in the next check too. But just in case minimum LeafCertTTL
// changes at some point, this validation must still be
// performed.
return fmt.Errorf("Intermediate Cert TTL must be greater or equal than %dh", 3*int(IntermediateCertRenewInterval.Hours()))
}
if c.IntermediateCertTTL < (3 * c.CommonCAProviderConfig.LeafCertTTL) {
// Intermediate Certificates are being sent to the proxy when
// the Leaf Certificate changes because they are bundled
// together.
// That means that the Intermediate Certificate TTL must be at
// a minimum of 3 * Leaf Certificate TTL to ensure that the new
// Intermediate is being set together with the Leaf Certificate
// before it expires.
return fmt.Errorf("Intermediate Cert TTL must be greater or equal than 3 * LeafCertTTL (>=%s).", 3*c.CommonCAProviderConfig.LeafCertTTL)
}
return nil
}
// CAConsulProviderState is used to track the built-in Consul CA provider's state.
type CAConsulProviderState struct {
ID string
PrivateKey string
RootCert string
IntermediateCert string
RaftIndex
}
type VaultCAProviderConfig struct {
CommonCAProviderConfig `mapstructure:",squash"`
Address string
Token string
RootPKIPath string
IntermediatePKIPath string
CAFile string
CAPath string
CertFile string
KeyFile string
TLSServerName string
TLSSkipVerify bool
}
type AWSCAProviderConfig struct {
CommonCAProviderConfig `mapstructure:",squash"`
ExistingARN string
DeleteOnExit bool
}
// CALeafOp is the operation for a request related to leaf certificates.
type CALeafOp string
const (
CALeafOpIncrementIndex CALeafOp = "increment-index"
)
// CALeafRequest is used to modify connect CA leaf data. This is used by the
// FSM (agent/consul/fsm) to apply changes.
type CALeafRequest struct {
// Op is the type of operation being requested. This determines what
// other fields are required.
Op CALeafOp
// Datacenter is the target for this request.
Datacenter string
// WriteRequest is a common struct containing ACL tokens and other
// write-related common elements for requests.
WriteRequest
}
// RequestDatacenter returns the datacenter for a given request.
func (q *CALeafRequest) RequestDatacenter() string {
return q.Datacenter
}
// ParseDurationFunc is a mapstructure hook for decoding a string or
// []uint8 into a time.Duration value.
func ParseDurationFunc() mapstructure.DecodeHookFunc {
return func(
f reflect.Type,
t reflect.Type,
data interface{}) (interface{}, error) {
var v time.Duration
if t != reflect.TypeOf(v) {
return data, nil
}
switch {
case f.Kind() == reflect.String:
if dur, err := time.ParseDuration(data.(string)); err != nil {
return nil, err
} else {
v = dur
}
return v, nil
case f == reflect.SliceOf(reflect.TypeOf(uint8(0))):
s := Uint8ToString(data.([]uint8))
if dur, err := time.ParseDuration(s); err != nil {
return nil, err
} else {
v = dur
}
return v, nil
default:
return data, nil
}
}
}
func Uint8ToString(bs []uint8) string {
b := make([]byte, len(bs))
for i, v := range bs {
b[i] = v
}
return string(b)
}