Revert "net: verify results from Lookup* are valid domain names"

This reverts commit c89f1224a5.

Reason for revert: reverting so we can apply follow-up fixes and do a single cherry pick.

Change-Id: I16c6283a0bcab056216f330fb98fa3b5f2b0780c
Reviewed-on: https://go-review.googlesource.com/c/go/+/323129
Reviewed-by: Katie Hockman <katie@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Trust: Katie Hockman <katie@golang.org>
Run-TryBot: Katie Hockman <katie@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
This commit is contained in:
Roland Shoemaker 2021-05-27 15:14:18 +00:00
parent 950fa11c4c
commit fca7b8f3e6
2 changed files with 8 additions and 211 deletions

View file

@ -1799,124 +1799,3 @@ func TestPTRandNonPTR(t *testing.T) {
t.Errorf("names = %q; want %q", names, want)
}
}
func TestCVE202133195(t *testing.T) {
fake := fakeDNSServer{
rh: func(n, _ string, q dnsmessage.Message, _ time.Time) (dnsmessage.Message, error) {
r := dnsmessage.Message{
Header: dnsmessage.Header{
ID: q.Header.ID,
Response: true,
RCode: dnsmessage.RCodeSuccess,
RecursionAvailable: true,
},
Questions: q.Questions,
}
switch q.Questions[0].Type {
case dnsmessage.TypeCNAME:
r.Answers = []dnsmessage.Resource{}
case dnsmessage.TypeA: // CNAME lookup uses a A/AAAA as a proxy
r.Answers = append(r.Answers,
dnsmessage.Resource{
Header: dnsmessage.ResourceHeader{
Name: dnsmessage.MustNewName("<html>.golang.org."),
Type: dnsmessage.TypeA,
Class: dnsmessage.ClassINET,
Length: 4,
},
Body: &dnsmessage.AResource{
A: TestAddr,
},
},
)
case dnsmessage.TypeSRV:
n := q.Questions[0].Name
if n.String() == "_hdr._tcp.golang.org." {
n = dnsmessage.MustNewName("<html>.golang.org.")
}
r.Answers = append(r.Answers,
dnsmessage.Resource{
Header: dnsmessage.ResourceHeader{
Name: n,
Type: dnsmessage.TypeSRV,
Class: dnsmessage.ClassINET,
Length: 4,
},
Body: &dnsmessage.SRVResource{
Target: dnsmessage.MustNewName("<html>.golang.org."),
},
},
)
case dnsmessage.TypeMX:
r.Answers = append(r.Answers,
dnsmessage.Resource{
Header: dnsmessage.ResourceHeader{
Name: dnsmessage.MustNewName("<html>.golang.org."),
Type: dnsmessage.TypeMX,
Class: dnsmessage.ClassINET,
Length: 4,
},
Body: &dnsmessage.MXResource{
MX: dnsmessage.MustNewName("<html>.golang.org."),
},
},
)
case dnsmessage.TypeNS:
r.Answers = append(r.Answers,
dnsmessage.Resource{
Header: dnsmessage.ResourceHeader{
Name: dnsmessage.MustNewName("<html>.golang.org."),
Type: dnsmessage.TypeNS,
Class: dnsmessage.ClassINET,
Length: 4,
},
Body: &dnsmessage.NSResource{
NS: dnsmessage.MustNewName("<html>.golang.org."),
},
},
)
case dnsmessage.TypePTR:
r.Answers = append(r.Answers,
dnsmessage.Resource{
Header: dnsmessage.ResourceHeader{
Name: dnsmessage.MustNewName("<html>.golang.org."),
Type: dnsmessage.TypePTR,
Class: dnsmessage.ClassINET,
Length: 4,
},
Body: &dnsmessage.PTRResource{
PTR: dnsmessage.MustNewName("<html>.golang.org."),
},
},
)
}
return r, nil
},
}
r := Resolver{PreferGo: true, Dial: fake.DialContext}
_, err := r.LookupCNAME(context.Background(), "golang.org")
if expected := "lookup golang.org: CNAME target is invalid"; err.Error() != expected {
t.Errorf("LookupCNAME returned unexpected error, got %q, want %q", err.Error(), expected)
}
_, _, err = r.LookupSRV(context.Background(), "target", "tcp", "golang.org")
if expected := "lookup golang.org: SRV target is invalid"; err.Error() != expected {
t.Errorf("LookupSRV returned unexpected error, got %q, want %q", err.Error(), expected)
}
_, _, err = r.LookupSRV(context.Background(), "hdr", "tcp", "golang.org")
if expected := "lookup golang.org: SRV header name is invalid"; err.Error() != expected {
t.Errorf("LookupSRV returned unexpected error, got %q, want %q", err.Error(), expected)
}
_, err = r.LookupMX(context.Background(), "golang.org")
if expected := "lookup golang.org: MX target is invalid"; err.Error() != expected {
t.Errorf("LookupMX returned unexpected error, got %q, want %q", err.Error(), expected)
}
_, err = r.LookupNS(context.Background(), "golang.org")
if expected := "lookup golang.org: NS target is invalid"; err.Error() != expected {
t.Errorf("LookupNS returned unexpected error, got %q, want %q", err.Error(), expected)
}
_, err = r.LookupAddr(context.Background(), "1.2.3.4")
if expected := "lookup 1.2.3.4: PTR target is invalid"; err.Error() != expected {
t.Errorf("LookupAddr returned unexpected error, got %q, want %q", err.Error(), expected)
}
}

View file

@ -396,9 +396,6 @@ func (r *Resolver) LookupPort(ctx context.Context, network, service string) (por
// contain DNS "CNAME" records, as long as host resolves to
// address records.
//
// The returned canonical name is validated to be a properly
// formatted presentation-format domain name.
//
// LookupCNAME uses context.Background internally; to specify the context, use
// Resolver.LookupCNAME.
func LookupCNAME(host string) (cname string, err error) {
@ -415,18 +412,8 @@ func LookupCNAME(host string) (cname string, err error) {
// LookupCNAME does not return an error if host does not
// contain DNS "CNAME" records, as long as host resolves to
// address records.
//
// The returned canonical name is validated to be a properly
// formatted presentation-format domain name.
func (r *Resolver) LookupCNAME(ctx context.Context, host string) (string, error) {
cname, err := r.lookupCNAME(ctx, host)
if err != nil {
return "", err
}
if !isDomainName(cname) {
return "", &DNSError{Err: "CNAME target is invalid", Name: host}
}
return cname, nil
func (r *Resolver) LookupCNAME(ctx context.Context, host string) (cname string, err error) {
return r.lookupCNAME(ctx, host)
}
// LookupSRV tries to resolve an SRV query of the given service,
@ -438,9 +425,6 @@ func (r *Resolver) LookupCNAME(ctx context.Context, host string) (string, error)
// That is, it looks up _service._proto.name. To accommodate services
// publishing SRV records under non-standard names, if both service
// and proto are empty strings, LookupSRV looks up name directly.
//
// The returned service names are validated to be properly
// formatted presentation-format domain names.
func LookupSRV(service, proto, name string) (cname string, addrs []*SRV, err error) {
return DefaultResolver.lookupSRV(context.Background(), service, proto, name)
}
@ -454,33 +438,12 @@ func LookupSRV(service, proto, name string) (cname string, addrs []*SRV, err err
// That is, it looks up _service._proto.name. To accommodate services
// publishing SRV records under non-standard names, if both service
// and proto are empty strings, LookupSRV looks up name directly.
//
// The returned service names are validated to be properly
// formatted presentation-format domain names.
func (r *Resolver) LookupSRV(ctx context.Context, service, proto, name string) (string, []*SRV, error) {
cname, addrs, err := r.lookupSRV(ctx, service, proto, name)
if err != nil {
return "", nil, err
}
if cname != "" && !isDomainName(cname) {
return "", nil, &DNSError{Err: "SRV header name is invalid", Name: name}
}
for _, addr := range addrs {
if addr == nil {
continue
}
if !isDomainName(addr.Target) {
return "", nil, &DNSError{Err: "SRV target is invalid", Name: name}
}
}
return cname, addrs, nil
func (r *Resolver) LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*SRV, err error) {
return r.lookupSRV(ctx, service, proto, name)
}
// LookupMX returns the DNS MX records for the given domain name sorted by preference.
//
// The returned mail server names are validated to be properly
// formatted presentation-format domain names.
//
// LookupMX uses context.Background internally; to specify the context, use
// Resolver.LookupMX.
func LookupMX(name string) ([]*MX, error) {
@ -488,30 +451,12 @@ func LookupMX(name string) ([]*MX, error) {
}
// LookupMX returns the DNS MX records for the given domain name sorted by preference.
//
// The returned mail server names are validated to be properly
// formatted presentation-format domain names.
func (r *Resolver) LookupMX(ctx context.Context, name string) ([]*MX, error) {
records, err := r.lookupMX(ctx, name)
if err != nil {
return nil, err
}
for _, mx := range records {
if mx == nil {
continue
}
if !isDomainName(mx.Host) {
return nil, &DNSError{Err: "MX target is invalid", Name: name}
}
}
return records, nil
return r.lookupMX(ctx, name)
}
// LookupNS returns the DNS NS records for the given domain name.
//
// The returned name server names are validated to be properly
// formatted presentation-format domain names.
//
// LookupNS uses context.Background internally; to specify the context, use
// Resolver.LookupNS.
func LookupNS(name string) ([]*NS, error) {
@ -519,23 +464,8 @@ func LookupNS(name string) ([]*NS, error) {
}
// LookupNS returns the DNS NS records for the given domain name.
//
// The returned name server names are validated to be properly
// formatted presentation-format domain names.
func (r *Resolver) LookupNS(ctx context.Context, name string) ([]*NS, error) {
records, err := r.lookupNS(ctx, name)
if err != nil {
return nil, err
}
for _, ns := range records {
if ns == nil {
continue
}
if !isDomainName(ns.Host) {
return nil, &DNSError{Err: "NS target is invalid", Name: name}
}
}
return records, nil
return r.lookupNS(ctx, name)
}
// LookupTXT returns the DNS TXT records for the given domain name.
@ -565,18 +495,6 @@ func LookupAddr(addr string) (names []string, err error) {
// LookupAddr performs a reverse lookup for the given address, returning a list
// of names mapping to that address.
//
// The returned names are validated to be properly
// formatted presentation-format domain names.
func (r *Resolver) LookupAddr(ctx context.Context, addr string) ([]string, error) {
names, err := r.lookupAddr(ctx, addr)
if err != nil {
return nil, err
}
for _, name := range names {
if !isDomainName(name) {
return nil, &DNSError{Err: "PTR target is invalid", Name: addr}
}
}
return names, nil
func (r *Resolver) LookupAddr(ctx context.Context, addr string) (names []string, err error) {
return r.lookupAddr(ctx, addr)
}