103 lines
3.2 KiB
Go
103 lines
3.2 KiB
Go
// Copyright 2018 The Go Cloud Development Kit Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// https://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
// Package rds contains Wire providers that are common across RDS.
|
|
package rds // import "gocloud.dev/aws/rds"
|
|
|
|
import (
|
|
"context"
|
|
"crypto/x509"
|
|
"encoding/pem"
|
|
"fmt"
|
|
"io"
|
|
"io/ioutil"
|
|
"net/http"
|
|
|
|
"github.com/google/wire"
|
|
"golang.org/x/net/context/ctxhttp"
|
|
)
|
|
|
|
// CertFetcherSet is a Wire provider set that provides the RDS certificate pool
|
|
// by pulling from Amazon's servers.
|
|
var CertFetcherSet = wire.NewSet(
|
|
wire.Struct(new(CertFetcher), "Client"),
|
|
wire.Bind(new(CertPoolProvider), new(*CertFetcher)),
|
|
)
|
|
|
|
// A CertPoolProvider obtains a certificate pool that contains the RDS CA certificate.
|
|
type CertPoolProvider interface {
|
|
RDSCertPool(context.Context) (*x509.CertPool, error)
|
|
}
|
|
|
|
// caBundleURL is the URL to the public RDS Certificate Authority keys.
|
|
const caBundleURL = "https://s3.amazonaws.com/rds-downloads/rds-combined-ca-bundle.pem"
|
|
|
|
// CertFetcher pulls the RDS CA certificates from Amazon's servers. The zero
|
|
// value will fetch certificates using the default HTTP client.
|
|
type CertFetcher struct {
|
|
// Client is the HTTP client used to make requests. If nil, then
|
|
// http.DefaultClient is used.
|
|
Client *http.Client
|
|
}
|
|
|
|
// RDSCertPool fetches the RDS CA certificates and places them into a pool.
|
|
// It is safe to call from multiple goroutines.
|
|
func (cf *CertFetcher) RDSCertPool(ctx context.Context) (*x509.CertPool, error) {
|
|
certs, err := cf.Fetch(ctx)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
certPool := x509.NewCertPool()
|
|
for _, c := range certs {
|
|
certPool.AddCert(c)
|
|
}
|
|
return certPool, nil
|
|
}
|
|
|
|
// Fetch fetches the RDS CA certificates. It is safe to call from multiple goroutines.
|
|
func (cf *CertFetcher) Fetch(ctx context.Context) ([]*x509.Certificate, error) {
|
|
client := cf.Client
|
|
if client == nil {
|
|
client = http.DefaultClient
|
|
}
|
|
resp, err := ctxhttp.Get(ctx, client, caBundleURL)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("fetch RDS certificates: %v", err)
|
|
}
|
|
defer resp.Body.Close()
|
|
if resp.StatusCode != http.StatusOK {
|
|
return nil, fmt.Errorf("fetch RDS certificates: HTTP %s", resp.Status)
|
|
}
|
|
pemData, err := ioutil.ReadAll(&io.LimitedReader{R: resp.Body, N: 1 << 20}) // limit to 1MiB
|
|
if err != nil {
|
|
return nil, fmt.Errorf("fetch RDS certificates: %v", err)
|
|
}
|
|
var certs []*x509.Certificate
|
|
for len(pemData) > 0 {
|
|
var block *pem.Block
|
|
block, pemData = pem.Decode(pemData)
|
|
if block == nil {
|
|
break
|
|
}
|
|
if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
|
|
continue
|
|
}
|
|
c, err := x509.ParseCertificate(block.Bytes)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("fetch RDS certificates: %v", err)
|
|
}
|
|
certs = append(certs, c)
|
|
}
|
|
return certs, nil
|
|
}
|