Implement workarounds for poor system CA pools

This commit is contained in:
Vladislav Yarmak 2021-04-28 17:56:53 +03:00
parent 67e4886843
commit c42142f5d6
2 changed files with 87 additions and 25 deletions

51
main.go
View file

@ -3,10 +3,12 @@ package main
import (
"context"
"crypto/tls"
"crypto/x509"
"encoding/csv"
"errors"
"flag"
"fmt"
"io/ioutil"
"log"
"net"
"net/http"
@ -42,20 +44,22 @@ func arg_fail(msg string) {
}
type CLIArgs struct {
country string
listCountries bool
listProxies bool
bindAddress string
verbosity int
timeout time.Duration
showVersion bool
proxy string
apiLogin string
apiPassword string
apiAddress string
bootstrapDNS string
refresh time.Duration
refreshRetry time.Duration
country string
listCountries bool
listProxies bool
bindAddress string
verbosity int
timeout time.Duration
showVersion bool
proxy string
apiLogin string
apiPassword string
apiAddress string
bootstrapDNS string
refresh time.Duration
refreshRetry time.Duration
certChainWorkaround bool
caFile string
}
func parse_args() CLIArgs {
@ -80,6 +84,9 @@ func parse_args() CLIArgs {
"Examples: https://1.1.1.1/dns-query, quic://dns.adguard.com")
flag.DurationVar(&args.refresh, "refresh", 4*time.Hour, "login refresh interval")
flag.DurationVar(&args.refreshRetry, "refresh-retry", 5*time.Second, "login refresh retry interval")
flag.BoolVar(&args.certChainWorkaround, "certchain-workaround", true,
"add bundled cross-signed intermediate cert to certchain to make it check out on old systems")
flag.StringVar(&args.caFile, "cafile", "", "use custom CA certificate bundle file")
flag.Parse()
if args.country == "" {
arg_fail("Country can't be empty string.")
@ -259,7 +266,21 @@ func run() int {
return basic_auth_header(seclient.GetProxyCredentials())
}
handlerDialer := NewProxyDialer(endpoint.NetAddr(), fmt.Sprintf("%s0.%s", args.country, PROXY_SUFFIX), auth, dialer)
var caPool *x509.CertPool
if args.caFile != "" {
caPool = x509.NewCertPool()
certs, err := ioutil.ReadFile(args.caFile)
if err != nil {
mainLogger.Error("Can't load CA file: %v", err)
return 15
}
if ok := caPool.AppendCertsFromPEM(certs); !ok {
mainLogger.Error("Can't load certificates from CA file")
return 15
}
}
handlerDialer := NewProxyDialer(endpoint.NetAddr(), fmt.Sprintf("%s0.%s", args.country, PROXY_SUFFIX), auth, args.certChainWorkaround, caPool, dialer)
mainLogger.Info("Endpoint: %s", endpoint.NetAddr())
mainLogger.Info("Starting proxy server...")
handler := NewProxyHandler(handlerDialer, proxyLogger)

View file

@ -6,6 +6,7 @@ import (
"context"
"crypto/tls"
"crypto/x509"
"encoding/pem"
"errors"
"fmt"
"io"
@ -20,10 +21,37 @@ const (
PROXY_CONNECT_METHOD = "CONNECT"
PROXY_HOST_HEADER = "Host"
PROXY_AUTHORIZATION_HEADER = "Proxy-Authorization"
MISSING_CHAIN_CERT = `-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
`
)
var UpstreamBlockedError = errors.New("blocked by upstream")
var missingLinkDER, _ = pem.Decode([]byte(MISSING_CHAIN_CERT))
var missingLink, _ = x509.ParseCertificate(missingLinkDER.Bytes)
type Dialer interface {
Dial(network, address string) (net.Conn, error)
}
@ -34,18 +62,22 @@ type ContextDialer interface {
}
type ProxyDialer struct {
address string
tlsServerName string
auth AuthProvider
next ContextDialer
address string
tlsServerName string
auth AuthProvider
next ContextDialer
intermediateWorkaround bool
caPool *x509.CertPool
}
func NewProxyDialer(address, tlsServerName string, auth AuthProvider, nextDialer ContextDialer) *ProxyDialer {
func NewProxyDialer(address, tlsServerName string, auth AuthProvider, intermediateWorkaround bool, caPool *x509.CertPool, nextDialer ContextDialer) *ProxyDialer {
return &ProxyDialer{
address: address,
tlsServerName: tlsServerName,
auth: auth,
next: nextDialer,
address: address,
tlsServerName: tlsServerName,
auth: auth,
next: nextDialer,
intermediateWorkaround: intermediateWorkaround,
caPool: caPool,
}
}
@ -79,7 +111,7 @@ func ProxyDialerFromURL(u *url.URL, next ContextDialer) (*ProxyDialer, error) {
return authHeader
}
}
return NewProxyDialer(address, tlsServerName, auth, next), nil
return NewProxyDialer(address, tlsServerName, auth, false, nil, next), nil
}
func (d *ProxyDialer) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
@ -105,9 +137,18 @@ func (d *ProxyDialer) DialContext(ctx context.Context, network, address string)
opts := x509.VerifyOptions{
DNSName: d.tlsServerName,
Intermediates: x509.NewCertPool(),
Roots: d.caPool,
}
waRequired := false
for _, cert := range cs.PeerCertificates[1:] {
opts.Intermediates.AddCert(cert)
if d.intermediateWorkaround && !waRequired &&
bytes.Compare(cert.AuthorityKeyId, missingLink.SubjectKeyId) == 0 {
waRequired = true
}
}
if waRequired {
opts.Intermediates.AddCert(missingLink)
}
_, err := cs.PeerCertificates[0].Verify(opts)
return err