Add DistinguishedName proto conversions (#65900)

* Add DistinguishedName proto conversions * Mention asn1.parseBase128Int validation of OIDs
2026-10-12 02:15:01 +00:00 · 2026-04-22 14:29:01 +00:00
parent 1429487b4b
commit fd2e58696d
2 changed files with 240 additions and 0 deletions
@@ -0,0 +1,102 @@
+// Teleport
+// Copyright (C) 2026 Gravitational, Inc.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package subca
+
+import (
+	"crypto/x509/pkix"
+
+	"github.com/gravitational/trace"
+
+	subcav1 "github.com/gravitational/teleport/api/gen/proto/go/teleport/subca/v1"
+)
+
+// RDNSequenceToDistinguishedNameProto converts a pkix.Name to a
+// subcav1.DistinguishedName proto.
+//
+// All ATV values must be strings. Always returns non-nil on success.
+func RDNSequenceToDistinguishedNameProto(rdns pkix.RDNSequence) (*subcav1.DistinguishedName, error) {
+	if len(rdns) == 0 {
+		return &subcav1.DistinguishedName{}, nil
+	}
+
+	// Usually it's one item per nameset. OK if not.
+	estimatedLen := len(rdns)
+
+	dn := &subcav1.DistinguishedName{
+		Names: make([]*subcav1.AttributeTypeAndValue, 0, estimatedLen),
+	}
+	for i, nameSet := range rdns {
+		for j, atv := range nameSet {
+			oid := make([]int32, len(atv.Type))
+			for i, x := range atv.Type {
+				// OID components are guaranteed to fit in a 32 bit integer as checked
+				// by encoding/asn1.parseBase128Int.
+				// https://cs.opensource.google/go/go/+/refs/tags/go1.26.2:src/encoding/asn1/asn1.go;l=323
+				oid[i] = int32(x)
+			}
+			val, ok := atv.Value.(string)
+			if !ok {
+				return nil, trace.BadParameter(
+					"rdns[%d][%d]: ATV value is not a string: %q=%v (%T)",
+					i, j,
+					atv.Type, atv.Value, atv.Value,
+				)
+			}
+			dn.Names = append(dn.Names, &subcav1.AttributeTypeAndValue{
+				Oid:   oid,
+				Value: &val,
+			})
+		}
+	}
+	return dn, nil
+}
+
+// DistinguishedNameProtoToRDNSequence converts a subcav1.DistinguishedName
+// proto to an RDNSequence.
+//
+// DistinguishedName protos are considered user-input, therefore this method
+// applies more strict validation than its sibling
+// [RDNSequenceToDistinguishedNameProto].
+//
+// A nil or empty DistinguishedName is considered invalid.
+func DistinguishedNameProtoToRDNSequence(dn *subcav1.DistinguishedName) (pkix.RDNSequence, error) {
+	if dn == nil || len(dn.Names) == 0 {
+		return nil, trace.BadParameter("empty distinguished name")
+	}
+
+	rdns := make(pkix.RDNSequence, 0, len(dn.Names))
+	for i, atv := range dn.Names {
+		switch {
+		case len(atv.GetOid()) == 0:
+			return nil, trace.BadParameter("names[%d]: empty OID", i)
+		case atv.Value == nil:
+			return nil, trace.BadParameter("names[%d]: nil Value", i)
+		}
+
+		oid := make([]int, len(atv.Oid))
+		for j, x := range atv.Oid {
+			oid[j] = int(x)
+		}
+		rdns = append(rdns, pkix.RelativeDistinguishedNameSET{
+			pkix.AttributeTypeAndValue{
+				Type:  oid,
+				Value: *atv.Value,
+			},
+		})
+	}
+	return rdns, nil
+}
@@ -0,0 +1,138 @@
+// Teleport
+// Copyright (C) 2026 Gravitational, Inc.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package subca_test
+
+import (
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/protobuf/testing/protocmp"
+
+	subcav1 "github.com/gravitational/teleport/api/gen/proto/go/teleport/subca/v1"
+	"github.com/gravitational/teleport/lib/subca"
+)
+
+func TestDistinguishedName_roundtrip(t *testing.T) {
+	t.Parallel()
+
+	want := (pkix.Name{
+		Organization: []string{"Llama"},
+		CommonName:   "Llamo",
+		ExtraNames: []pkix.AttributeTypeAndValue{
+			{Type: asn1.ObjectIdentifier{1, 2, 3, 4}, Value: "alpaca"},
+		},
+	}).ToRDNSequence()
+
+	dn, err := subca.RDNSequenceToDistinguishedNameProto(want)
+	require.NoError(t, err, "RDNSequenceToDistinguishedNameProto errored")
+
+	got, err := subca.DistinguishedNameProtoToRDNSequence(dn)
+	require.NoError(t, err, "DistinguishedNameProtoToRDNSequence errored")
+	assert.Equal(t, want, got, "DistinguishedName roundtrip mismatch")
+}
+
+func TestRDNSequenceToDistinguishedNameProto(t *testing.T) {
+	t.Parallel()
+
+	// Success tested by TestDistinguishedName_roundtrip.
+
+	t.Run("nil", func(t *testing.T) {
+		t.Parallel()
+		got, err := subca.RDNSequenceToDistinguishedNameProto(nil)
+		require.NoError(t, err)
+		want := &subcav1.DistinguishedName{}
+		if diff := cmp.Diff(want, got, protocmp.Transform()); diff != "" {
+			t.Errorf("DistinguishedName mismatch (-want +got)\n%s", diff)
+		}
+	})
+
+	t.Run("non-string value", func(t *testing.T) {
+		t.Parallel()
+
+		rdns := (pkix.Name{
+			ExtraNames: []pkix.AttributeTypeAndValue{
+				{Type: asn1.ObjectIdentifier{1, 2, 3, 4}, Value: "ok"}, // OK
+				{Type: asn1.ObjectIdentifier{1, 2, 3, 5}, Value: 42},   // NOK
+			},
+		}).ToRDNSequence()
+
+		_, err := subca.RDNSequenceToDistinguishedNameProto(rdns)
+		assert.ErrorContains(t, err, "not a string", "error mismatch")
+	})
+}
+
+func TestDistinguishedNameProtoToRDNSequence(t *testing.T) {
+	t.Parallel()
+
+	// Success tested by TestDistinguishedName_roundtrip.
+
+	exampleValue := "alpaca"
+
+	tests := []struct {
+		name    string
+		dn      *subcav1.DistinguishedName
+		wantErr string
+	}{
+		{
+			name:    "nil",
+			wantErr: "empty distinguished name",
+		},
+		{
+			name:    "empty",
+			dn:      &subcav1.DistinguishedName{},
+			wantErr: "empty distinguished name",
+		},
+		{
+			name: "ATV nil",
+			dn: &subcav1.DistinguishedName{
+				Names: []*subcav1.AttributeTypeAndValue{
+					nil,
+				},
+			},
+			wantErr: "empty OID",
+		},
+		{
+			name: "ATV.OID empty",
+			dn: &subcav1.DistinguishedName{
+				Names: []*subcav1.AttributeTypeAndValue{
+					{Oid: []int32{}, Value: &exampleValue},
+				},
+			},
+			wantErr: "empty OID",
+		},
+		{
+			name: "ATV.Value nil",
+			dn: &subcav1.DistinguishedName{
+				Names: []*subcav1.AttributeTypeAndValue{
+					{Oid: []int32{1, 2, 3, 4}},
+				},
+			},
+			wantErr: "nil Value",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+			_, err := subca.DistinguishedNameProtoToRDNSequence(test.dn)
+			assert.ErrorContains(t, err, test.wantErr, "error mismatch")
+		})
+	}
+}