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client.go
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client.go
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// Copyright 2019 - MinIO, Inc. All rights reserved.
// Use of this source code is governed by the AGPLv3
// license that can be found in the LICENSE file.
package kes
import (
"bytes"
"context"
"crypto/tls"
"encoding/json"
"errors"
"io"
"math"
"net"
"net/http"
"net/url"
"path"
"strings"
"time"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/common/expfmt"
)
// Client is a KES client. Usually, a new client is
// instantiated via the NewClient or NewClientWithConfig
// functions.
//
// In general, a client just requires:
// - a KES server endpoint
// - a X.509 certificate for authentication
//
// However, custom transport protocols, timeouts,
// connection pooling, etc. can be specified via
// a custom http.RoundTripper. For example:
//
// client := &Client{
// Endpoints: []string{"https:127.0.0.1:7373"},
// HTTPClient: http.Client{
// Transport: &http.Transport{
// // specify custom behavior...
//
// TLSClientConfig: &tls.Config{
// Certificates: []tls.Certificates{clientCert},
// },
// },
// },
// }
//
// A custom transport protocol can be used via a
// custom implemention of the http.RoundTripper
// interface.
type Client struct {
// Endpoints contains one or multiple KES server
// endpoints. For example: https://127.0.0.1:7373
//
// Each endpoint must be a HTTPS endpoint and
// should point to different KES server replicas
// with a common configuration.
//
// Multiple endpoints should only be specified
// when multiple KES servers should be used, e.g.
// for high availability, but no round-robin DNS
// is used.
Endpoints []string
// HTTPClient is the HTTP client.
//
// The HTTP client uses its http.RoundTripper
// to send requests resp. receive responses.
//
// It must not be modified concurrently.
HTTPClient http.Client
}
// NewClient returns a new KES client with the given
// KES server endpoint that uses the given TLS certificate
// mTLS authentication.
//
// The TLS certificate must be valid for client authentication.
//
// NewClient uses an http.Transport with reasonable defaults.
func NewClient(endpoint string, cert tls.Certificate) *Client {
return NewClientWithConfig(endpoint, &tls.Config{
MinVersion: tls.VersionTLS13,
Certificates: []tls.Certificate{cert},
})
}
// NewClientWithConfig returns a new KES client with the
// given KES server endpoint that uses the given TLS config
// for mTLS authentication.
//
// Therefore, the config.Certificates must contain a TLS
// certificate that is valid for client authentication.
//
// NewClientWithConfig uses an http.Transport with reasonable
// defaults.
func NewClientWithConfig(endpoint string, config *tls.Config) *Client {
return &Client{
Endpoints: []string{endpoint},
HTTPClient: http.Client{
Transport: &http.Transport{
Proxy: http.ProxyFromEnvironment,
DialContext: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
DualStack: true,
}).DialContext,
ForceAttemptHTTP2: true,
MaxIdleConns: 100,
IdleConnTimeout: 90 * time.Second,
TLSHandshakeTimeout: 10 * time.Second,
ExpectContinueTimeout: 1 * time.Second,
TLSClientConfig: config,
},
},
}
}
// Version tries to fetch the version information from the
// KES server.
func (c *Client) Version(ctx context.Context) (string, error) {
const (
APIPath = "/version"
Method = http.MethodGet
StatusOK = http.StatusOK
MaxResponeSize = 1024 // 1 KB
)
client := retry(c.HTTPClient)
resp, err := client.Send(ctx, Method, c.Endpoints, APIPath, nil)
if err != nil {
return "", err
}
if resp.StatusCode != StatusOK {
return "", parseErrorResponse(resp)
}
type Response struct {
Version string `json:"version"`
}
var response Response
if err = json.NewDecoder(limitBody(resp, MaxResponeSize)).Decode(&response); err != nil {
return "", err
}
return response.Version, nil
}
// Status returns the current state of the KES server.
func (c *Client) Status(ctx context.Context) (State, error) {
const (
APIPath = "/v1/status"
Method = http.MethodGet
StatusOK = http.StatusOK
MaxResponseSize = 1 << 20 // 1 MB
)
client := retry(c.HTTPClient)
resp, err := client.Send(ctx, Method, c.Endpoints, APIPath, nil)
if err != nil {
return State{}, err
}
if resp.StatusCode != StatusOK {
return State{}, parseErrorResponse(resp)
}
type Response struct {
Version string `json:"version"`
OS string `json:"os"`
Arch string `json:"arch"`
UpTime time.Duration `json:"uptime"`
CPUs int `json:"num_cpu"`
UsableCPUs int `json:"num_cpu_used"`
HeapAlloc uint64 `json:"mem_heap_used"`
StackAlloc uint64 `json:"mem_stack_used"`
}
var response Response
if err = json.NewDecoder(limitBody(resp, MaxResponseSize)).Decode(&response); err != nil {
return State{}, err
}
return State(response), nil
}
// APIs returns a list of all API endpoints supported
// by the KES server.
//
// It returns ErrNotAllowed if the client does not
// have sufficient permissions to fetch the server
// APIs.
func (c *Client) APIs(ctx context.Context) ([]API, error) {
const (
APIPath = "/v1/api"
Method = http.MethodGet
StatusOK = http.StatusOK
MaxResponseSize = 1 << 20 // 1 MB
)
client := retry(c.HTTPClient)
resp, err := client.Send(ctx, Method, c.Endpoints, APIPath, nil)
if err != nil {
return nil, err
}
if resp.StatusCode != StatusOK {
return nil, parseErrorResponse(resp)
}
type Response struct {
Method string `json:"method"`
Path string `json:"path"`
MaxBody int64 `json:"max_body"`
Timeout int64 `json:"timeout"` // Timeout in seconds
}
var responses []Response
if err = json.NewDecoder(limitBody(resp, MaxResponseSize)).Decode(&responses); err != nil {
return nil, err
}
apis := make([]API, 0, len(responses))
for _, response := range responses {
apis = append(apis, API{
Method: response.Method,
Path: response.Path,
MaxBody: response.MaxBody,
Timeout: time.Second * time.Duration(response.Timeout),
})
}
return apis, nil
}
// CreateEnclave creates a new enclave with the given
// identity as enclave admin. Only the KES system
// admin can create new enclaves.
//
// It returns ErrEnclaveExists if the enclave already
// exists.
func (c *Client) CreateEnclave(ctx context.Context, name string, admin Identity) error {
const (
APIPath = "/v1/enclave/create"
Method = http.MethodPost
StatusOK = http.StatusOK
)
type Request struct {
Admin Identity `json:"admin"`
}
body, err := json.Marshal(Request{
Admin: admin,
})
if err != nil {
return err
}
client := retry(c.HTTPClient)
resp, err := client.Send(ctx, Method, c.Endpoints, join(APIPath, name), bytes.NewReader(body))
if err != nil {
return err
}
if resp.StatusCode != StatusOK {
return parseErrorResponse(resp)
}
return nil
}
// DeleteEnclave delete the specified enclave. Only the
// KES system admin can delete enclaves.
//
// It returns ErrEnclaveNotFound if the enclave does not
// exist.
func (c *Client) DeleteEnclave(ctx context.Context, name string) error {
const (
APIPath = "/v1/enclave/delete"
Method = http.MethodDelete
StatusOK = http.StatusOK
)
client := retry(c.HTTPClient)
resp, err := client.Send(ctx, Method, c.Endpoints, join(APIPath, name), nil)
if err != nil {
return err
}
if resp.StatusCode != StatusOK {
return parseErrorResponse(resp)
}
return nil
}
// CreateKey creates a new cryptographic key. The key will
// be generated by the KES server.
//
// It returns ErrKeyExists if a key with the same name already
// exists.
func (c *Client) CreateKey(ctx context.Context, name string) error {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.CreateKey(ctx, name)
}
// ImportKey imports the given key into a KES server. It
// returns ErrKeyExists if a key with the same key already
// exists.
func (c *Client) ImportKey(ctx context.Context, name string, key []byte) error {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.ImportKey(ctx, name, key)
}
// DeleteKey deletes the key from a KES server. It returns
// ErrKeyNotFound if no such key exists.
func (c *Client) DeleteKey(ctx context.Context, name string) error {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.DeleteKey(ctx, name)
}
// GenerateKey returns a new generated data encryption key (DEK).
// A DEK has a plaintext and ciphertext representation.
//
// The former should be used for cryptographic operations, like
// encrypting some data.
//
// The later is the result of encrypting the plaintext with the named
// key at the KES server. It should be stored at a durable location but
// does not need to stay secret. The ciphertext can only be decrypted
// with the named key at the KES server.
//
// The context is cryptographically bound to the ciphertext and the
// same context value must be provided when decrypting the ciphertext
// via Decrypt. Therefore, an application must either remember the
// context or must be able to re-generate it.
//
// GenerateKey returns ErrKeyNotFound if no key with the given name
// exists.
func (c *Client) GenerateKey(ctx context.Context, name string, context []byte) (DEK, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.GenerateKey(ctx, name, context)
}
// Encrypt encrypts the given plaintext with the named key at the
// KES server. The optional context is cryptographically bound to
// the returned ciphertext. The exact same context must be provided
// when decrypting the ciphertext again.
//
// Encrypt returns ErrKeyNotFound if no such key exists at the KES
// server.
func (c *Client) Encrypt(ctx context.Context, name string, plaintext, context []byte) ([]byte, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.Encrypt(ctx, name, plaintext, context)
}
// Decrypt decrypts the ciphertext with the named key at the KES
// server. The exact same context, used during Encrypt, must be
// provided.
//
// Decrypt returns ErrKeyNotFound if no such key exists. It returns
// ErrDecrypt when the ciphertext has been modified or a different
// context value is provided.
func (c *Client) Decrypt(ctx context.Context, name string, ciphertext, context []byte) ([]byte, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.Decrypt(ctx, name, ciphertext, context)
}
// DecryptAll decrypts all ciphertexts with the named key at the
// KES server. It either returns all decrypted plaintexts or the
// first decryption error.
//
// DecryptAll returns ErrKeyNotFound if the specified key does not
// exist. It returns ErrDecrypt if any ciphertext has been modified
// or a different context value was used.
func (c *Client) DecryptAll(ctx context.Context, name string, ciphertexts ...CCP) ([]PCP, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.DecryptAll(ctx, name, ciphertexts...)
}
// ListKeys lists all names of cryptographic keys that match the given
// pattern. It returns a KeyIterator that iterates over all matched key
// names.
//
// The pattern matching happens on the server side. If pattern is empty
// the KeyIterator iterates over all key names.
func (c *Client) ListKeys(ctx context.Context, pattern string) (*KeyIterator, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.ListKeys(ctx, pattern)
}
// SetPolicy creates the given policy. If a policy with the same
// name already exists, SetPolicy overwrites the existing policy
// with the given one. Any existing identites will be assigned to
// the given policy.
func (c *Client) SetPolicy(ctx context.Context, name string, policy *Policy) error {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.SetPolicy(ctx, name, policy)
}
// DescribePolicy returns the PolicyInfo for the given policy.
// It returns ErrPolicyNotFound if no such policy exists.
func (c *Client) DescribePolicy(ctx context.Context, name string) (*PolicyInfo, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.DescribePolicy(ctx, name)
}
// GetPolicy returns the policy with the given name.
// It returns ErrPolicyNotFound if no such policy
// exists.
func (c *Client) GetPolicy(ctx context.Context, name string) (*Policy, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.GetPolicy(ctx, name)
}
// DeletePolicy deletes the policy with the given name. Any
// assigned identities will be removed as well.
//
// It returns ErrPolicyNotFound if no such policy exists.
func (c *Client) DeletePolicy(ctx context.Context, name string) error {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.DeletePolicy(ctx, name)
}
// ListPolicies lists all policy names that match the given pattern.
// It returns a PolicyIterator that iterates over all matched policies.
//
// The pattern matching happens on the server side. If pattern is empty
// ListPolicies returns all policy names.
func (c *Client) ListPolicies(ctx context.Context, pattern string) (*PolicyIterator, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.ListPolicies(ctx, pattern)
}
// AssignPolicy assigns the policy to the identity.
// The KES admin identity cannot be assigned to any
// policy.
//
// AssignPolicy returns PolicyNotFound if no such policy exists.
func (c *Client) AssignPolicy(ctx context.Context, policy string, identity Identity) error {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.AssignPolicy(ctx, policy, identity)
}
// DescribeIdentity returns an IdentityInfo describing the given identity.
func (c *Client) DescribeIdentity(ctx context.Context, identity Identity) (*IdentityInfo, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.DescribeIdentity(ctx, identity)
}
// DescribeSelf returns an IdentityInfo describing the identity
// making the API request. It also returns the assigned policy,
// if any.
//
// DescribeSelf allows an application to obtain identity and
// policy information about itself.
func (c *Client) DescribeSelf(ctx context.Context) (*IdentityInfo, *Policy, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.DescribeSelf(ctx)
}
// DeleteIdentity removes the identity. Once removed, any
// operation issued by this identity will fail with
// ErrNotAllowed.
//
// The KES admin identity cannot be removed.
func (c *Client) DeleteIdentity(ctx context.Context, identity Identity) error {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.DeleteIdentity(ctx, identity)
}
// ListIdentities lists all identites that match the given pattern.
//
// The pattern matching happens on the server side. If pattern is empty
// ListIdentities returns all identities.
func (c *Client) ListIdentities(ctx context.Context, pattern string) (*IdentityIterator, error) {
enclave := Enclave{
endpoints: c.Endpoints,
client: retry(c.HTTPClient),
}
return enclave.ListIdentities(ctx, pattern)
}
// AuditLog returns a stream of audit events produced by the
// KES server. The stream does not contain any events that
// happened in the past.
//
// It returns ErrNotAllowed if the client does not
// have sufficient permissions to subscribe to the
// audit log.
func (c *Client) AuditLog(ctx context.Context) (*AuditStream, error) {
const (
APIPath = "/v1/log/audit"
Method = http.MethodGet
StatusOK = http.StatusOK
)
client := retry(c.HTTPClient)
resp, err := client.Send(ctx, Method, c.Endpoints, APIPath, nil)
if err != nil {
return nil, err
}
if resp.StatusCode != StatusOK {
return nil, parseErrorResponse(resp)
}
return NewAuditStream(resp.Body), nil
}
// ErrorLog returns a stream of error events produced by the
// KES server. The stream does not contain any events that
// happened in the past.
//
// It returns ErrNotAllowed if the client does not
// have sufficient permissions to subscribe to the
// error log.
func (c *Client) ErrorLog(ctx context.Context) (*ErrorStream, error) {
const (
APIPath = "/v1/log/error"
Method = http.MethodGet
StatusOK = http.StatusOK
)
client := retry(c.HTTPClient)
resp, err := client.Send(ctx, Method, c.Endpoints, APIPath, nil)
if err != nil {
return nil, err
}
if resp.StatusCode != StatusOK {
return nil, parseErrorResponse(resp)
}
return NewErrorStream(resp.Body), nil
}
// Metrics returns a KES server metric snapshot.
//
// It returns ErrNotAllowed if the client does not
// have sufficient permissions to fetch server metrics.
func (c *Client) Metrics(ctx context.Context) (Metric, error) {
const (
APIPath = "/v1/metrics"
Method = http.MethodGet
StatusOK = http.StatusOK
MaxResponeSize = 1 << 20 // 1 MB
)
client := retry(c.HTTPClient)
resp, err := client.Send(ctx, Method, c.Endpoints, APIPath, nil)
if err != nil {
return Metric{}, err
}
if resp.StatusCode != StatusOK {
return Metric{}, parseErrorResponse(resp)
}
defer resp.Body.Close()
const (
MetricRequestOK = "kes_http_request_success"
MetricRequestErr = "kes_http_request_error"
MetricRequestFail = "kes_http_request_failure"
MetricRequestActive = "kes_http_request_active"
MetricAuditEvents = "kes_log_audit_events"
MetricErrorEvents = "kes_log_error_events"
MetricResponseTime = "kes_http_response_time"
MetricSystemUpTme = "kes_system_up_time"
MetricSystemCPUs = "kes_system_num_cpu"
MetricSystemUsableCPUs = "kes_system_num_cpu_used"
MetricSystemThreads = "kes_system_num_threads"
MetricSystemHeapUsed = "kes_system_mem_heap_used"
MetricSystemHeapObjects = "kes_system_mem_heap_objects"
MetricSystemStackUsed = "kes_system_mem_stack_used"
)
var (
metric Metric
metricFamily dto.MetricFamily
)
decoder := expfmt.NewDecoder(limitBody(resp, MaxResponeSize), expfmt.ResponseFormat(resp.Header))
for {
err := decoder.Decode(&metricFamily)
if err == io.EOF {
break
}
if err != nil {
return Metric{}, err
}
if len(metricFamily.Metric) != 1 {
return Metric{}, errors.New("kes: server response contains more than one metric")
}
var (
name = metricFamily.GetName()
kind = metricFamily.GetType()
rawMetric = metricFamily.GetMetric()[0] // Safe since we checked length before
)
switch {
case kind == dto.MetricType_COUNTER && name == MetricRequestOK:
metric.RequestOK = uint64(rawMetric.GetCounter().GetValue())
case kind == dto.MetricType_COUNTER && name == MetricRequestErr:
metric.RequestErr = uint64(rawMetric.GetCounter().GetValue())
case kind == dto.MetricType_COUNTER && name == MetricRequestFail:
metric.RequestFail = uint64(rawMetric.GetCounter().GetValue())
case kind == dto.MetricType_GAUGE && name == MetricRequestActive:
metric.RequestActive = uint64(rawMetric.GetGauge().GetValue())
case kind == dto.MetricType_COUNTER && name == MetricAuditEvents:
metric.AuditEvents = uint64(rawMetric.GetCounter().GetValue())
case kind == dto.MetricType_COUNTER && name == MetricErrorEvents:
metric.ErrorEvents = uint64(rawMetric.GetCounter().GetValue())
case kind == dto.MetricType_HISTOGRAM && name == MetricResponseTime:
metric.LatencyHistogram = map[time.Duration]uint64{}
for _, bucket := range rawMetric.GetHistogram().GetBucket() {
if math.IsInf(bucket.GetUpperBound(), 0) { // Ignore the +Inf bucket
continue
}
duration := time.Duration(1000*bucket.GetUpperBound()) * time.Millisecond
metric.LatencyHistogram[duration] = bucket.GetCumulativeCount()
}
delete(metric.LatencyHistogram, 0) // Delete the artificial zero entry
case kind == dto.MetricType_GAUGE && name == MetricSystemUpTme:
metric.UpTime = time.Duration(rawMetric.GetGauge().GetValue()) * time.Second
case kind == dto.MetricType_GAUGE && name == MetricSystemCPUs:
metric.CPUs = int(rawMetric.GetGauge().GetValue())
case kind == dto.MetricType_GAUGE && name == MetricSystemUsableCPUs:
metric.UsableCPUs = int(rawMetric.GetGauge().GetValue())
case kind == dto.MetricType_GAUGE && name == MetricSystemThreads:
metric.Threads = int(rawMetric.GetGauge().GetValue())
case kind == dto.MetricType_GAUGE && name == MetricSystemHeapUsed:
metric.HeapAlloc = uint64(rawMetric.GetGauge().GetValue())
case kind == dto.MetricType_GAUGE && name == MetricSystemHeapObjects:
metric.HeapObjects = uint64(rawMetric.GetGauge().GetValue())
case kind == dto.MetricType_GAUGE && name == MetricSystemStackUsed:
metric.StackAlloc = uint64(rawMetric.GetGauge().GetValue())
}
}
return metric, nil
}
// Join joins any number of arguments with the API path.
// All arguments are path-escaped before joining.
func join(api string, args ...string) string {
for _, arg := range args {
api = path.Join(api, url.PathEscape(arg))
}
return api
}
// endpoint returns an endpoint URL starting with the
// given endpoint followed by the path elements.
//
// For example:
// - endpoint("https://127.0.0.1:7373", "version") => "https://127.0.0.1:7373/version"
// - endpoint("https://127.0.0.1:7373/", "/key/create", "my-key") => "https://127.0.0.1:7373/key/create/my-key"
//
// Any leading or trailing whitespaces are removed from
// the endpoint before it is concatenated with the path
// elements.
//
// The path elements will not be URL-escaped.
func endpoint(endpoint string, elems ...string) string {
endpoint = strings.TrimSpace(endpoint)
endpoint = strings.TrimSuffix(endpoint, "/")
if len(elems) > 0 && !strings.HasPrefix(elems[0], "/") {
endpoint += "/"
}
return endpoint + path.Join(elems...)
}
// limitBody returns the response body limited to at most
// maxLen bytes. If the response content length is smaller
// then maxLen, the returned io.Reader may return less than
// maxLen bytes.
func limitBody(r *http.Response, maxLen int64) io.Reader {
size := r.ContentLength
if size < 0 || size > maxLen {
size = maxLen
}
return io.LimitReader(r.Body, size)
}