Files
teleport/lib/auth/join.go
T

595 lines
18 KiB
Go

/*
* Teleport
* Copyright (C) 2023 Gravitational, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package auth
import (
"context"
"crypto/rand"
"encoding/base64"
"encoding/json"
"errors"
"log/slog"
"slices"
"strings"
"github.com/gravitational/trace"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
"google.golang.org/protobuf/types/known/structpb"
"google.golang.org/protobuf/types/known/timestamppb"
"github.com/gravitational/teleport/api/client/proto"
machineidv1pb "github.com/gravitational/teleport/api/gen/proto/go/teleport/machineid/v1"
workloadidentityv1pb "github.com/gravitational/teleport/api/gen/proto/go/teleport/workloadidentity/v1"
"github.com/gravitational/teleport/api/types"
apievents "github.com/gravitational/teleport/api/types/events"
"github.com/gravitational/teleport/lib/auth/machineid/machineidv1"
"github.com/gravitational/teleport/lib/defaults"
"github.com/gravitational/teleport/lib/events"
)
// tokenJoinMethod returns the join method of the token with the given tokenName
func (a *Server) tokenJoinMethod(ctx context.Context, tokenName string) types.JoinMethod {
provisionToken, err := a.GetToken(ctx, tokenName)
if err != nil {
// could not find dynamic token, assume static token. If it does not
// exist this will be caught later.
return types.JoinMethodToken
}
return provisionToken.GetJoinMethod()
}
// checkTokenJoinRequestCommon checks all token join rules that are common to
// all join methods, including token existence, token TTL, and allowed roles.
func (a *Server) checkTokenJoinRequestCommon(ctx context.Context, req *types.RegisterUsingTokenRequest) (types.ProvisionToken, error) {
// make sure the token is valid
provisionToken, err := a.ValidateToken(ctx, req.Token)
if err != nil {
a.logger.WarnContext(ctx, "cannot join the cluster with invalid token",
"node_name", req.NodeName,
"role", req.Role,
"error", err,
)
msg := "the token is not valid" // default to most generic message
if strings.Contains(err.Error(), TokenExpiredOrNotFound) {
// propagate ExpiredOrNotFound message so that clients can attempt
// assertion-based fallback if appropriate.
msg = TokenExpiredOrNotFound
}
return nil, trace.AccessDenied("%q can not join the cluster with role %q, %s", req.NodeName, req.Role, msg)
}
// instance certs can be requested by any agent that has at least one local service role (e.g. proxy, node, etc).
if req.Role == types.RoleInstance {
hasLocalServiceRole := false
for _, role := range provisionToken.GetRoles() {
if role.IsLocalService() {
hasLocalServiceRole = true
break
}
}
if !hasLocalServiceRole {
a.logger.WarnContext(ctx, "cannot requisition instance certs (token contains no local service roles)",
"node_name", req.NodeName,
"host_id", req.HostID,
)
return nil, trace.AccessDenied("%s [%v] cannot requisition instance certs (token contains no local service roles)", req.NodeName, req.HostID)
}
}
// make sure the caller is requesting a role allowed by the token
if !provisionToken.GetRoles().Include(req.Role) && req.Role != types.RoleInstance {
a.logger.WarnContext(ctx, "token does not allow role to join the cluster",
"node_name", req.NodeName,
"host_id", req.HostID,
"role", req.Role,
)
return nil, trace.BadParameter("node %q [%v] can not join the cluster, the token does not allow %q role", req.NodeName, req.HostID, req.Role)
}
return provisionToken, nil
}
// handleJoinFailure logs and audits the failure of a join. It is intentionally
// designed to handle potential nullness of the input parameters.
func (a *Server) handleJoinFailure(
ctx context.Context,
origErr error,
pt types.ProvisionToken,
rawJoinAttrs any,
req *types.RegisterUsingTokenRequest,
) {
attrs := []slog.Attr{slog.Any("error", origErr)}
if req != nil {
attrs = append(attrs, []slog.Attr{
slog.String("role", string(req.Role)),
slog.String("host_id", req.HostID),
slog.String("node_name", req.NodeName),
slog.String("remote_addr", req.RemoteAddr),
}...)
}
// Fetch and encode rawJoinAttrs if they are available.
attributesStruct, err := rawJoinAttrsToStruct(rawJoinAttrs)
if err != nil {
a.logger.WarnContext(ctx, "Unable to fetch join attributes from join method", "error", err)
}
if attributesStruct != nil {
attrs = append(attrs, slog.Any("attributes", attributesStruct))
}
// Add log fields from token if available.
if pt != nil {
attrs = append(attrs, slog.String("join_method", string(pt.GetJoinMethod())))
attrs = append(attrs, slog.String("token_name", pt.GetSafeName()))
}
a.logger.LogAttrs(ctx, slog.LevelWarn, "Failure to join cluster occurred", attrs...)
errorMessage := origErr.Error()
if errors.Is(origErr, context.Canceled) || status.Code(origErr) == codes.Canceled {
errorMessage = "join attempt timed out or was aborted"
}
var evt apievents.AuditEvent
status := apievents.Status{
Success: false,
Error: errorMessage,
}
if req != nil && req.Role == types.RoleBot {
botJoinEvent := &apievents.BotJoin{
Metadata: apievents.Metadata{
Type: events.BotJoinEvent,
Code: events.BotJoinFailureCode,
},
Status: status,
Attributes: attributesStruct,
ConnectionMetadata: apievents.ConnectionMetadata{
RemoteAddr: req.RemoteAddr,
},
}
if pt != nil {
botJoinEvent.Method = string(pt.GetJoinMethod())
botJoinEvent.TokenName = pt.GetSafeName()
botJoinEvent.BotName = pt.GetBotName()
}
evt = botJoinEvent
} else {
instanceJoinEvent := &apievents.InstanceJoin{
Metadata: apievents.Metadata{
Type: events.InstanceJoinEvent,
Code: events.InstanceJoinFailureCode,
},
Status: status,
Attributes: attributesStruct,
}
if pt != nil {
instanceJoinEvent.Method = string(pt.GetJoinMethod())
instanceJoinEvent.TokenName = pt.GetSafeName()
}
if req != nil {
instanceJoinEvent.Role = string(req.Role)
instanceJoinEvent.NodeName = req.NodeName
instanceJoinEvent.HostID = req.HostID
instanceJoinEvent.RemoteAddr = req.RemoteAddr
}
evt = instanceJoinEvent
}
if err := a.emitter.EmitAuditEvent(a.closeCtx, evt); err != nil {
a.logger.WarnContext(ctx, "Failed to emit failed join event", "error", err)
}
}
// RegisterUsingToken returns credentials for a new node to join the Teleport
// cluster using a previously issued token.
//
// A node must also request a specific role (and the role must match one of the roles
// the token was generated for.)
//
// If a token was generated with a TTL, it gets enforced (can't register new
// nodes after TTL expires.)
//
// If the token includes a specific join method, the rules for that join method
// will be checked.
func (a *Server) RegisterUsingToken(ctx context.Context, req *types.RegisterUsingTokenRequest) (certs *proto.Certs, err error) {
attrs := &workloadidentityv1pb.JoinAttrs{}
var rawClaims any
var provisionToken types.ProvisionToken
defer func() {
// Emit a log message and audit event on join failure.
if err != nil {
a.handleJoinFailure(ctx, err, provisionToken, rawClaims, req)
}
}()
if err := req.CheckAndSetDefaults(); err != nil {
return nil, trace.Wrap(err)
}
method := a.tokenJoinMethod(ctx, req.Token)
switch method {
case types.JoinMethodEC2:
if err := a.checkEC2JoinRequest(ctx, req); err != nil {
return nil, trace.Wrap(err)
}
case types.JoinMethodIAM, types.JoinMethodAzure, types.JoinMethodTPM, types.JoinMethodOracle:
// These join methods must use gRPC register methods
return nil, trace.AccessDenied("this token is only valid for the %s "+
"join method but the node has connected to the wrong endpoint, make "+
"sure your node is configured to use the %s join method", method, method)
case types.JoinMethodGitHub:
claims, err := a.checkGitHubJoinRequest(ctx, req)
if claims != nil {
rawClaims = claims
attrs.Github = claims.JoinAttrs()
}
if err != nil {
return nil, trace.Wrap(err)
}
case types.JoinMethodGitLab:
claims, err := a.checkGitLabJoinRequest(ctx, req)
if claims != nil {
rawClaims = claims
attrs.Gitlab = claims.JoinAttrs()
}
if err != nil {
return nil, trace.Wrap(err)
}
case types.JoinMethodCircleCI:
claims, err := a.checkCircleCIJoinRequest(ctx, req)
if claims != nil {
rawClaims = claims
attrs.Circleci = claims.JoinAttrs()
}
if err != nil {
return nil, trace.Wrap(err)
}
case types.JoinMethodKubernetes:
claims, err := a.checkKubernetesJoinRequest(ctx, req)
if claims != nil {
rawClaims = claims
attrs.Kubernetes = claims.JoinAttrs()
}
if err != nil {
return nil, trace.Wrap(err)
}
case types.JoinMethodGCP:
claims, err := a.checkGCPJoinRequest(ctx, req)
if claims != nil {
rawClaims = claims
attrs.Gcp = claims.JoinAttrs()
}
if err != nil {
return nil, trace.Wrap(err)
}
case types.JoinMethodSpacelift:
claims, err := a.checkSpaceliftJoinRequest(ctx, req)
if claims != nil {
rawClaims = claims
attrs.Spacelift = claims.JoinAttrs()
}
if err != nil {
return nil, trace.Wrap(err)
}
case types.JoinMethodTerraformCloud:
claims, err := a.checkTerraformCloudJoinRequest(ctx, req)
if claims != nil {
rawClaims = claims
attrs.TerraformCloud = claims.JoinAttrs()
}
if err != nil {
return nil, trace.Wrap(err)
}
case types.JoinMethodBitbucket:
claims, err := a.checkBitbucketJoinRequest(ctx, req)
if claims != nil {
rawClaims = claims
attrs.Bitbucket = claims.JoinAttrs()
}
if err != nil {
return nil, trace.Wrap(err)
}
case types.JoinMethodToken:
// carry on to common token checking logic
default:
// this is a logic error, all valid join methods should be captured
// above (empty join method will be set to JoinMethodToken by
// CheckAndSetDefaults)
return nil, trace.BadParameter("unrecognized token join method")
}
// perform common token checks
provisionToken, err = a.checkTokenJoinRequestCommon(ctx, req)
if err != nil {
return nil, trace.Wrap(err)
}
// With all elements of the token validated, we can now generate & return
// certificates.
if req.Role == types.RoleBot {
certs, err = a.generateCertsBot(
ctx,
provisionToken,
req,
rawClaims,
attrs,
)
return certs, trace.Wrap(err)
}
certs, err = a.generateCerts(ctx, provisionToken, req, rawClaims)
return certs, trace.Wrap(err)
}
func (a *Server) generateCertsBot(
ctx context.Context,
provisionToken types.ProvisionToken,
req *types.RegisterUsingTokenRequest,
rawJoinClaims any,
attrs *workloadidentityv1pb.JoinAttrs,
) (*proto.Certs, error) {
// bots use this endpoint but get a user cert
// botResourceName must be set, enforced in CheckAndSetDefaults
botName := provisionToken.GetBotName()
joinMethod := provisionToken.GetJoinMethod()
// Check this is a join method for bots we support.
if !slices.Contains(machineidv1.SupportedJoinMethods, joinMethod) {
return nil, trace.BadParameter(
"unsupported join method %q for bot", joinMethod,
)
}
// Most join methods produce non-renewable certificates and join must be
// called again to fetch fresh certificates with a longer lifetime. These
// join methods do not delete the token after use.
renewable := false
shouldDeleteToken := false
if joinMethod == types.JoinMethodToken {
// The token join method is special and produces renewable certificates
// but the token is deleted after use.
shouldDeleteToken = true
renewable = true
}
expires := a.GetClock().Now().Add(defaults.DefaultRenewableCertTTL)
if req.Expires != nil {
expires = *req.Expires
}
// Construct a Join event to be sent later.
joinEvent := &apievents.BotJoin{
Metadata: apievents.Metadata{
Type: events.BotJoinEvent,
Code: events.BotJoinCode,
},
Status: apievents.Status{
Success: true,
},
BotName: botName,
Method: string(joinMethod),
TokenName: provisionToken.GetSafeName(),
UserName: machineidv1.BotResourceName(botName),
ConnectionMetadata: apievents.ConnectionMetadata{
RemoteAddr: req.RemoteAddr,
},
}
var err error
joinEvent.Attributes, err = rawJoinAttrsToStruct(rawJoinClaims)
if err != nil {
a.logger.WarnContext(
ctx,
"Unable to encode join attributes for join audit event",
"error", err,
)
}
// Prepare join attributes for encoding into the X509 cert and for inclusion
// in audit logs.
if attrs == nil {
attrs = &workloadidentityv1pb.JoinAttrs{}
}
attrs.Meta = &workloadidentityv1pb.JoinAttrsMeta{
JoinMethod: string(joinMethod),
}
if joinMethod != types.JoinMethodToken {
attrs.Meta.JoinTokenName = provisionToken.GetName()
}
auth := &machineidv1pb.BotInstanceStatusAuthentication{
AuthenticatedAt: timestamppb.New(a.GetClock().Now()),
// TODO: GetSafeName may not return an appropriate value for later
// comparison / locking purposes, and this also shouldn't contain
// secrets. Should we hash it?
JoinToken: provisionToken.GetSafeName(),
JoinMethod: string(provisionToken.GetJoinMethod()),
// TODO(nklaassen): consider logging the SSH public key as well, for now
// the SSH and TLS public keys are still identical for tbot.
PublicKey: req.PublicTLSKey,
JoinAttrs: attrs,
}
// TODO(noah): In v19, we can drop writing to the deprecated Metadata field.
auth.Metadata, err = rawJoinAttrsToGoogleStruct(rawJoinClaims)
if err != nil {
a.logger.WarnContext(ctx, "Unable to encode struct value for join metadata", "error", err)
}
certs, botInstanceID, err := a.generateInitialBotCerts(
ctx,
botName,
machineidv1.BotResourceName(botName),
req.RemoteAddr,
req.PublicSSHKey,
req.PublicTLSKey,
expires,
renewable,
auth,
req.BotInstanceID,
req.BotGeneration,
attrs,
)
if err != nil {
return nil, trace.Wrap(err)
}
joinEvent.BotInstanceID = botInstanceID
if shouldDeleteToken {
// delete ephemeral bot join tokens so they can't be re-used
if err := a.DeleteToken(ctx, provisionToken.GetName()); err != nil {
a.logger.WarnContext(ctx, "Could not delete bot provision token after generating certs",
"provision_token", provisionToken.GetSafeName(),
"error", err,
)
}
}
// Emit audit event for bot join.
a.logger.InfoContext(ctx, "Bot has joined the cluster",
"bot_name", botName,
"bot_instance", botInstanceID,
)
if err := a.emitter.EmitAuditEvent(ctx, joinEvent); err != nil {
a.logger.WarnContext(ctx, "Failed to emit bot join event", "error", err)
}
return certs, nil
}
func (a *Server) generateCerts(
ctx context.Context,
provisionToken types.ProvisionToken,
req *types.RegisterUsingTokenRequest,
rawJoinClaims any,
) (*proto.Certs, error) {
if req.Expires != nil {
return nil, trace.BadParameter("'expires' cannot be set on join for non-bot certificates")
}
// instance certs include an additional field that specifies the list of
// all services authorized by the token.
var systemRoles []types.SystemRole
if req.Role == types.RoleInstance {
for _, r := range provisionToken.GetRoles() {
if r.IsLocalService() {
systemRoles = append(systemRoles, r)
} else {
a.logger.WarnContext(ctx, "Omitting non-service system role from instance cert", "system_role", string(r))
}
}
}
// generate and return host certificate and keys
certs, err := a.GenerateHostCerts(ctx,
&proto.HostCertsRequest{
HostID: req.HostID,
NodeName: req.NodeName,
Role: req.Role,
AdditionalPrincipals: req.AdditionalPrincipals,
PublicTLSKey: req.PublicTLSKey,
PublicSSHKey: req.PublicSSHKey,
RemoteAddr: req.RemoteAddr,
DNSNames: req.DNSNames,
SystemRoles: systemRoles,
})
if err != nil {
return nil, trace.Wrap(err)
}
// Emit audit event
if req.Role == types.RoleInstance {
a.logger.InfoContext(ctx, "Instance has joined the cluster",
"node_name", req.NodeName,
"host_id", req.HostID,
"role", req.Role,
"system_roles", systemRoles,
)
} else {
a.logger.InfoContext(ctx, "Instance has joined the cluster",
"node_name", req.NodeName,
"host_id", req.HostID,
"role", req.Role,
)
}
joinEvent := &apievents.InstanceJoin{
Metadata: apievents.Metadata{
Type: events.InstanceJoinEvent,
Code: events.InstanceJoinCode,
},
Status: apievents.Status{
Success: true,
},
NodeName: req.NodeName,
Role: string(req.Role),
Method: string(provisionToken.GetJoinMethod()),
TokenName: provisionToken.GetSafeName(),
TokenExpires: provisionToken.Expiry(),
HostID: req.HostID,
ConnectionMetadata: apievents.ConnectionMetadata{
RemoteAddr: req.RemoteAddr,
},
}
joinEvent.Attributes, err = rawJoinAttrsToStruct(rawJoinClaims)
if err != nil {
a.logger.WarnContext(ctx, "Unable to fetch join attributes from join method", "error", err)
}
if err := a.emitter.EmitAuditEvent(ctx, joinEvent); err != nil {
a.logger.WarnContext(ctx, "Failed to emit instance join event", "error", err)
}
return certs, nil
}
func rawJoinAttrsToStruct(in any) (*apievents.Struct, error) {
if in == nil {
return nil, nil
}
attrBytes, err := json.Marshal(in)
if err != nil {
return nil, trace.Wrap(err, "marshaling join attributes")
}
out := &apievents.Struct{}
if err := out.UnmarshalJSON(attrBytes); err != nil {
return nil, trace.Wrap(err, "unmarshaling join attributes")
}
return out, nil
}
func rawJoinAttrsToGoogleStruct(in any) (*structpb.Struct, error) {
if in == nil {
return nil, nil
}
attrBytes, err := json.Marshal(in)
if err != nil {
return nil, trace.Wrap(err, "marshaling join attributes")
}
out := &structpb.Struct{}
if err := out.UnmarshalJSON(attrBytes); err != nil {
return nil, trace.Wrap(err, "unmarshaling join attributes")
}
return out, nil
}
func generateChallenge(encoding *base64.Encoding, length int) (string, error) {
// read crypto-random bytes to generate the challenge
challengeRawBytes := make([]byte, length)
if _, err := rand.Read(challengeRawBytes); err != nil {
return "", trace.Wrap(err)
}
// encode the challenge to base64 so it can be sent over HTTP
return encoding.EncodeToString(challengeRawBytes), nil
}