222 lines
11 KiB
Go
222 lines
11 KiB
Go
// Copyright (c) HashiCorp, Inc.
|
|
// SPDX-License-Identifier: MPL-2.0
|
|
|
|
package ca
|
|
|
|
import (
|
|
"crypto/x509"
|
|
"errors"
|
|
)
|
|
|
|
//go:generate mockery --name Provider --inpackage
|
|
|
|
// ErrRateLimited is a sentinel error value Providers may return from any method
|
|
// to indicate that the operation can't complete due to a temporary rate limit.
|
|
// In the case of signing new certificates, Consul clients will respect this and
|
|
// intelligently backoff to optimize rotation rollout time while reducing load
|
|
// on servers and CA provider.
|
|
var ErrRateLimited = errors.New("operation rate limited by CA provider")
|
|
|
|
// PrimaryUsesIntermediate is an optional interface that CA providers may implement
|
|
// to indicate that they use an intermediate cert in the primary datacenter as
|
|
// well as the secondary. This is used when determining whether to run the
|
|
// intermediate renewal routine in the primary.
|
|
type PrimaryUsesIntermediate interface {
|
|
// GenerateLeafSigningCert returns a new intermediate signing cert and sets it to
|
|
// the active intermediate. If multiple intermediates are needed to complete
|
|
// the chain from the signing certificate back to the active root, they should
|
|
// all by bundled here.
|
|
GenerateLeafSigningCert() (string, error)
|
|
}
|
|
|
|
// ProviderConfig encapsulates all the data Consul passes to `Configure` on a
|
|
// new provider instance. The provider must treat this as read-only and make
|
|
// copies of any map or slice if it might modify them internally.
|
|
type ProviderConfig struct {
|
|
// ClusterID is the current Consul cluster ID.
|
|
ClusterID string
|
|
|
|
// Datacenter is the current Consul datacenter.
|
|
Datacenter string
|
|
|
|
// IsPrimary is true when the CA instance is in the primary DC typically it
|
|
// may choose to act as a root in this case while secondaries are typically
|
|
// intermediate CAs. In some case the primary DC in Consul is an intermediate
|
|
// signed by some external CA along with that CA's public cert so the old name
|
|
// of `IsRoot` was misleading.
|
|
IsPrimary bool
|
|
|
|
// RawConfig is the user configuration for the provider and is
|
|
// provider-specific to be interpreted as the provider wishes.
|
|
RawConfig map[string]interface{}
|
|
|
|
// State contains the State the same provider last persisted. It is provided
|
|
// after a restart or reconfiguration, or on a leader election on a new server
|
|
// to maintain operation. It MUST NOT be used for secret storage since it is
|
|
// visible in the API to operators. It's intended use is to store small bits
|
|
// of state like UUIDs of external resources that the provider has created and
|
|
// needs to continue to manage.
|
|
State map[string]string
|
|
}
|
|
|
|
// Provider is the interface for Consul to interact with
|
|
// an external CA that provides leaf certificate signing for
|
|
// given SpiffeIDServices.
|
|
type Provider interface {
|
|
// Configure initializes the provider based on the given cluster ID, root
|
|
// status and configuration values. rawConfig contains the user-provided
|
|
// Config. State contains a the State the same provider last persisted on a
|
|
// restart or reconfiguration. The provider must not modify `rawConfig` or
|
|
// `state` maps directly as it may be being read from other goroutines.
|
|
Configure(cfg ProviderConfig) error
|
|
|
|
// State returns the current provider state. If the provider doesn't need to
|
|
// store anything other than what the user configured this can return nil. It
|
|
// is called after any config change before the new active config is stored in
|
|
// the state store and the most recent value returned by the provider is given
|
|
// in subsequent `Configure` calls provided that the current provider is the
|
|
// same type as the new provider instance being configured. This provides a
|
|
// simple way for providers to persist information like UUIDs of resources
|
|
// they manage. This state is visible to anyone with operator:read via the API
|
|
// so it's not intended for storing secrets like root private keys. Only
|
|
// strings are permitted since this has to pass through msgpack and so
|
|
// interface values will end up mangled in many cases which is ugly for all
|
|
// provider code to have to remember to reason about.
|
|
//
|
|
// Note that the map returned will be accessed (read-only) in other goroutines
|
|
// - for example passed to Configure in the Connect CA Config RPC endpoint -
|
|
// so it must not just be a pointer to a map that may internally be modified.
|
|
// If the Provider only writes to it during Configure it's safe to return
|
|
// as-is, but otherwise it's assumed the map returned is a copy of the state
|
|
// in the Provider struct so it won't change after being returned.
|
|
State() (map[string]string, error)
|
|
|
|
// ActiveLeafSigningCert returns the current signing cert used by this provider
|
|
// for generating SPIFFE leaf certs. Note that this must not change except
|
|
// when Consul requests the change via GenerateLeafSigningCert. Changing the
|
|
// signing cert will break Consul's assumptions about which validation paths
|
|
// are active.
|
|
ActiveLeafSigningCert() (string, error)
|
|
|
|
// Sign signs a leaf certificate used by Connect proxies from a CSR. The PEM
|
|
// returned should include only the leaf certificate as all Intermediates
|
|
// needed to validate it will be added by Consul based on the active
|
|
// intermediate and any cross-signed intermediates managed by Consul. Note that
|
|
// providers should return ErrRateLimited if they are unable to complete the
|
|
// operation due to upstream rate limiting so that clients can intelligently
|
|
// backoff.
|
|
Sign(*x509.CertificateRequest) (string, error)
|
|
|
|
// Cleanup performs any necessary cleanup that should happen when the provider
|
|
// is shut down permanently, such as removing a temporary PKI backend in Vault
|
|
// created for an intermediate CA. Whether the CA provider type is changing
|
|
// and the other providers raw configuration is passed along so that the provider
|
|
// instance can determine which cleanup steps to perform. For example, when the
|
|
// Vault provider is in use and there is no type change occuring, the Vault
|
|
// provider should check if the intermediate PKI path is changing. If it is not
|
|
// changing then the provider should not remove that path from Vault.
|
|
Cleanup(providerTypeChange bool, otherConfig map[string]interface{}) error
|
|
|
|
// TODO: when CAManager has separate types for primary/secondary invert this
|
|
// relationship so that PrimaryProvider/SecondaryProvider embed Provider
|
|
|
|
PrimaryProvider
|
|
SecondaryProvider
|
|
}
|
|
|
|
type PrimaryProvider interface {
|
|
// GenerateCAChain is called:
|
|
// * to initialize the CA system when a server is elected as a raft leader
|
|
// * when the CA configuration is updated in a way that might require
|
|
// generating a new root certificate.
|
|
//
|
|
// In both cases GenerateCAChain is always called on a newly created provider
|
|
// after calling Provider.Configure, and before any other calls to the
|
|
// provider.
|
|
//
|
|
// Depending on the provider and its configuration, GenerateCAChain may return
|
|
// a single root certificate or a chain of certs.
|
|
// The first certificate must be the primary CA used to sign intermediates for
|
|
// secondary datacenters, and the last certificate must be the trusted CA.
|
|
// The provider should return an existing CA chain if one exists or generate a
|
|
// new one and return it.
|
|
GenerateCAChain() (string, error)
|
|
|
|
// SignIntermediate will validate the CSR to ensure the trust domain in the
|
|
// URI SAN matches the local one and that basic constraints for a CA
|
|
// certificate are met. It should return a signed CA certificate with a path
|
|
// length constraint of 0 to ensure that the certificate cannot be used to
|
|
// generate further CA certs. Note that providers should return ErrRateLimited
|
|
// if they are unable to complete the operation due to upstream rate limiting
|
|
// so that clients can intelligently backoff.
|
|
SignIntermediate(*x509.CertificateRequest) (string, error)
|
|
|
|
// CrossSignCA must accept a CA certificate from another CA provider and cross
|
|
// sign it exactly as it is such that it forms a chain back the the
|
|
// CAProvider's current root. Specifically, the Distinguished Name, Subject
|
|
// Alternative Name, SubjectKeyID and other relevant extensions must be kept.
|
|
// The resulting certificate must have a distinct Serial Number and the
|
|
// AuthorityKeyID set to the CAProvider's current signing key as well as the
|
|
// Issuer related fields changed as necessary. The resulting certificate is
|
|
// returned as a PEM formatted string.
|
|
//
|
|
// If the CA provider does not support this operation, it may return an error
|
|
// provided `SupportsCrossSigning` also returns false. Note that
|
|
// providers should return ErrRateLimited if they are unable to complete the
|
|
// operation due to upstream rate limiting so that clients can intelligently
|
|
// backoff.
|
|
CrossSignCA(*x509.Certificate) (string, error)
|
|
|
|
// SupportsCrossSigning should indicate whether the CA provider supports
|
|
// cross-signing an external root to provide a seamless rotation. If the CA
|
|
// does not support this, the user will have to force an upgrade when that CA
|
|
// provider is the current CA as the upgrade may cause interruptions to
|
|
// connectivity during the rollout.
|
|
SupportsCrossSigning() (bool, error)
|
|
}
|
|
|
|
type SecondaryProvider interface {
|
|
// GenerateIntermediateCSR should return a CSR for an intermediate CA
|
|
// certificate. The intermediate CA will be signed by the primary CA and
|
|
// should be used by the provider to sign leaf certificates in the local
|
|
// datacenter.
|
|
//
|
|
// After the certificate is signed, SecondaryProvider.SetIntermediate will
|
|
// be called to store the intermediate CA.
|
|
//
|
|
// The second return value is an opaque string meant to be passed back to
|
|
// the subsequent call to SetIntermediate.
|
|
GenerateIntermediateCSR() (string, string, error)
|
|
|
|
// SetIntermediate is called to store a newly signed leaf signing certificate and
|
|
// the chain of certificates back to the root CA certificate.
|
|
//
|
|
// The provider should save the certificates and use them to
|
|
// Provider.Sign leaf certificates.
|
|
SetIntermediate(intermediatePEM, rootPEM, opaque string) error
|
|
}
|
|
|
|
// CAChainResult is the result returned by PrimaryProvider.GenerateCAChain.
|
|
type CAChainResult struct {
|
|
// PEM encoded bundle of CA certificates. The first certificate must be the
|
|
// primary CA used to sign intermediates for secondary datacenters, and the
|
|
// last certificate must be the trusted CA.
|
|
//
|
|
// If there is only a single certificate in the bundle then it will be used
|
|
// as both the primary CA and the trusted CA.
|
|
PEM string
|
|
|
|
// IntermediatePEM is an encoded bundle of CA certificates used only by
|
|
// providers that use an intermediate CA to sign leaf certificates (e.g.
|
|
// Vault). Its issuer should form a chain leading to the trusted CA in PEM.
|
|
IntermediatePEM string
|
|
}
|
|
|
|
// NeedsStop is an optional interface that allows a CA to define a function
|
|
// to be called when the CA instance is no longer in use. This is different
|
|
// from Cleanup(), as only the local provider instance is being shut down
|
|
// such as in the case of a leader change.
|
|
type NeedsStop interface {
|
|
Stop()
|
|
}
|