open-vault/vault/wrapping.go
Jeff Mitchell 64fc18e523 When a JWT wrapping token is returned, audit the inner token both for
request and response. This makes it far easier to properly check
validity elsewhere in Vault because we simply replace the request client
token with the inner value.
2017-01-04 23:50:24 -05:00

311 lines
8.8 KiB
Go

package vault
import (
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"encoding/json"
"fmt"
"strings"
"time"
"github.com/SermoDigital/jose/crypto"
"github.com/SermoDigital/jose/jws"
"github.com/SermoDigital/jose/jwt"
"github.com/hashicorp/errwrap"
"github.com/hashicorp/vault/helper/jsonutil"
"github.com/hashicorp/vault/logical"
)
const (
// The location of the key used to generate response-wrapping JWTs
coreWrappingJWTKeyPath = "core/wrapping/jwtkey"
)
func (c *Core) ensureWrappingKey() error {
entry, err := c.barrier.Get(coreWrappingJWTKeyPath)
if err != nil {
return err
}
var keyParams clusterKeyParams
if entry == nil {
key, err := ecdsa.GenerateKey(elliptic.P521(), rand.Reader)
if err != nil {
return errwrap.Wrapf("failed to generate wrapping key: {{err}}", err)
}
keyParams.D = key.D
keyParams.X = key.X
keyParams.Y = key.Y
keyParams.Type = corePrivateKeyTypeP521
val, err := jsonutil.EncodeJSON(keyParams)
if err != nil {
return errwrap.Wrapf("failed to encode wrapping key: {{err}}", err)
}
entry = &Entry{
Key: coreWrappingJWTKeyPath,
Value: val,
}
if err = c.barrier.Put(entry); err != nil {
return errwrap.Wrapf("failed to store wrapping key: {{err}}", err)
}
}
// Redundant if we just created it, but in this case serves as a check anyways
if err = jsonutil.DecodeJSON(entry.Value, &keyParams); err != nil {
return errwrap.Wrapf("failed to decode wrapping key parameters: {{err}}", err)
}
c.wrappingJWTKey = &ecdsa.PrivateKey{
PublicKey: ecdsa.PublicKey{
Curve: elliptic.P521(),
X: keyParams.X,
Y: keyParams.Y,
},
D: keyParams.D,
}
c.logger.Info("core: loaded wrapping token key")
return nil
}
func (c *Core) wrapInCubbyhole(req *logical.Request, resp *logical.Response) (*logical.Response, error) {
// Before wrapping, obey special rules for listing: if no entries are
// found, 404. This prevents unwrapping only to find empty data.
if req.Operation == logical.ListOperation {
if resp == nil || len(resp.Data) == 0 {
return nil, logical.ErrUnsupportedPath
}
keysRaw, ok := resp.Data["keys"]
if !ok || keysRaw == nil {
return nil, logical.ErrUnsupportedPath
}
keys, ok := keysRaw.([]string)
if !ok {
return nil, logical.ErrUnsupportedPath
}
if len(keys) == 0 {
return nil, logical.ErrUnsupportedPath
}
}
var err error
// If we are wrapping, the first part (performed in this functions) happens
// before auditing so that resp.WrapInfo.Token can contain the HMAC'd
// wrapping token ID in the audit logs, so that it can be determined from
// the audit logs whether the token was ever actually used.
creationTime := time.Now()
te := TokenEntry{
Path: req.Path,
Policies: []string{"response-wrapping"},
CreationTime: creationTime.Unix(),
TTL: resp.WrapInfo.TTL,
NumUses: 1,
ExplicitMaxTTL: resp.WrapInfo.TTL,
}
if err := c.tokenStore.create(&te); err != nil {
c.logger.Error("core: failed to create wrapping token", "error", err)
return nil, ErrInternalError
}
resp.WrapInfo.Token = te.ID
resp.WrapInfo.CreationTime = creationTime
// This will only be non-nil if this response contains a token, so in that
// case put the accessor in the wrap info.
if resp.Auth != nil {
resp.WrapInfo.WrappedAccessor = resp.Auth.Accessor
}
switch resp.WrapInfo.Format {
case "jwt":
// Create the JWT
claims := jws.Claims{}
// Map the JWT ID to the token ID for ease ofuse
claims.SetJWTID(te.ID)
// Set the issue time to the creation time
claims.SetIssuedAt(creationTime)
// Set the expiration to the TTL
claims.SetExpiration(creationTime.Add(resp.WrapInfo.TTL))
if resp.Auth != nil {
claims.Set("accessor", resp.Auth.Accessor)
}
claims.Set("type", "wrapping")
claims.Set("addr", c.redirectAddr)
jwt := jws.NewJWT(claims, crypto.SigningMethodES512)
serWebToken, err := jwt.Serialize(c.wrappingJWTKey)
if err != nil {
c.logger.Error("core: failed to serialize JWT", "error", err)
return nil, ErrInternalError
}
resp.WrapInfo.Token = string(serWebToken)
}
cubbyReq := &logical.Request{
Operation: logical.CreateOperation,
Path: "cubbyhole/response",
ClientToken: te.ID,
}
// During a rewrap, store the original response, don't wrap it again.
if req.Path == "sys/wrapping/rewrap" {
cubbyReq.Data = map[string]interface{}{
"response": resp.Data["response"],
}
} else {
httpResponse := logical.LogicalResponseToHTTPResponse(resp)
// Add the unique identifier of the original request to the response
httpResponse.RequestID = req.ID
// Because of the way that JSON encodes (likely just in Go) we actually get
// mixed-up values for ints if we simply put this object in the response
// and encode the whole thing; so instead we marshal it first, then store
// the string response. This actually ends up making it easier on the
// client side, too, as it becomes a straight read-string-pass-to-unmarshal
// operation.
marshaledResponse, err := json.Marshal(httpResponse)
if err != nil {
c.logger.Error("core: failed to marshal wrapped response", "error", err)
return nil, ErrInternalError
}
cubbyReq.Data = map[string]interface{}{
"response": string(marshaledResponse),
}
}
cubbyResp, err := c.router.Route(cubbyReq)
if err != nil {
// Revoke since it's not yet being tracked for expiration
c.tokenStore.Revoke(te.ID)
c.logger.Error("core: failed to store wrapped response information", "error", err)
return nil, ErrInternalError
}
if cubbyResp != nil && cubbyResp.IsError() {
c.tokenStore.Revoke(te.ID)
c.logger.Error("core: failed to store wrapped response information", "error", cubbyResp.Data["error"])
return cubbyResp, nil
}
// Store info for lookup
cubbyReq.Path = "cubbyhole/wrapinfo"
cubbyReq.Data = map[string]interface{}{
"creation_ttl": resp.WrapInfo.TTL,
"creation_time": creationTime,
}
cubbyResp, err = c.router.Route(cubbyReq)
if err != nil {
// Revoke since it's not yet being tracked for expiration
c.tokenStore.Revoke(te.ID)
c.logger.Error("core: failed to store wrapping information", "error", err)
return nil, ErrInternalError
}
if cubbyResp != nil && cubbyResp.IsError() {
c.tokenStore.Revoke(te.ID)
c.logger.Error("core: failed to store wrapping information", "error", cubbyResp.Data["error"])
return cubbyResp, nil
}
auth := &logical.Auth{
ClientToken: te.ID,
Policies: []string{"response-wrapping"},
LeaseOptions: logical.LeaseOptions{
TTL: te.TTL,
Renewable: false,
},
}
// Register the wrapped token with the expiration manager
if err := c.expiration.RegisterAuth(te.Path, auth); err != nil {
// Revoke since it's not yet being tracked for expiration
c.tokenStore.Revoke(te.ID)
c.logger.Error("core: failed to register cubbyhole wrapping token lease", "request_path", req.Path, "error", err)
return nil, ErrInternalError
}
return nil, nil
}
func (c *Core) ValidateWrappingToken(req *logical.Request) (bool, error) {
if req == nil {
return false, fmt.Errorf("invalid request")
}
var err error
var token string
var thirdParty bool
if req.Data != nil && req.Data["token"] != nil {
thirdParty = true
if tokenStr, ok := req.Data["token"].(string); !ok {
return false, fmt.Errorf("could not decode token in request body")
} else if tokenStr == "" {
return false, fmt.Errorf("empty token in request body")
} else {
token = tokenStr
}
} else {
token = req.ClientToken
}
// Check for it being a JWT. If it is, and it is valid, we extract the
// internal client token from it and use that during lookup.
if strings.Count(token, ".") == 2 {
wt, err := jws.ParseJWT([]byte(token))
// If there's an error we simply fall back to attempting to use it as a regular token
if err == nil && wt != nil {
validator := &jwt.Validator{}
validator.SetClaim("type", "wrapping")
if err = wt.Validate(&c.wrappingJWTKey.PublicKey, crypto.SigningMethodES512, []*jwt.Validator{validator}...); err != nil {
return false, errwrap.Wrapf("wrapping token signature could not be validated: {{err}}", err)
}
token, _ = wt.Claims().JWTID()
// We override the given request client token so that the rest of
// Vault sees the real value. This also ensures audit logs are
// consistent with the actual token that was issued.
if !thirdParty {
req.ClientToken = token
} else {
req.Data["token"] = token
}
}
}
if token == "" {
return false, fmt.Errorf("token is empty")
}
c.stateLock.RLock()
defer c.stateLock.RUnlock()
if c.sealed {
return false, ErrSealed
}
if c.standby {
return false, ErrStandby
}
te, err := c.tokenStore.Lookup(token)
if err != nil {
return false, err
}
if te == nil {
return false, nil
}
if len(te.Policies) != 1 {
return false, nil
}
if te.Policies[0] != responseWrappingPolicyName {
return false, nil
}
return true, nil
}