[v17] Add support for JSON format to '/webapi/auth/export' endpoint (#…

…52325)

* Add support for HTTP 'Accept' header to '/webapi/auth/export' endpoint

Signed-off-by: Fred Heinecke <[email protected]>

* Switch PR to use new `format` parameter

---------

Signed-off-by: Fred Heinecke <[email protected]>

lib/client/ca_export.go

@@ -77,7 +77,7 @@ type ExportedAuthority struct {
 	// Data is the output of the exported authority.
 	// May be an SSH authorized key, an SSH known hosts entry, a DER or a PEM,
 	// depending on the type of the exported authority.
-	Data []byte
+	Data []byte `json:"data"`
 }
 
 // ExportAllAuthorities exports public keys of all authorities of a particular

lib/web/ca_export.go

@@ -19,6 +19,7 @@ package web
 import (
 	"archive/zip"
 	"bytes"
+	"encoding/json"
 	"fmt"
 	"net/http"
 	"time"
@@ -52,12 +53,6 @@ func (h *Handler) authExportPublicError(w http.ResponseWriter, r *http.Request,
 
 	query := r.URL.Query()
 	caType := query.Get("type") // validated by ExportAllAuthorities
-	format := query.Get("format")
-
-	const formatZip = "zip"
-	if format != "" && format != formatZip {
-		return trace.BadParameter("unsupported format %q", format)
-	}
 
 	ctx := r.Context()
 	authorities, err := client.ExportAllAuthorities(
@@ -72,11 +67,23 @@ func (h *Handler) authExportPublicError(w http.ResponseWriter, r *http.Request,
 		return trace.Wrap(err)
 	}
 
-	if format == formatZip {
+	format := query.Get("format")
+
+	const formatZip = "zip"
+	const formatJSON = "json"
+	switch format {
+	case "":
+		break
+	case formatZip:
 		return h.authExportPublicZip(w, r, authorities)
+	case formatJSON:
+		return h.authExportPublicJSON(w, r, authorities)
+	default:
+		return trace.BadParameter("unsupported format %q", format)
 	}
+
 	if l := len(authorities); l > 1 {
-		return trace.BadParameter("found %d authorities to export, use format=%s to export all", l, formatZip)
+		return trace.BadParameter("found %d authorities to export, use format=%s or format=%s to export all", l, formatZip, formatJSON)
 	}
 
 	// ServeContent sets the correct headers: Content-Type, Content-Length and Accept-Ranges.
@@ -119,3 +126,19 @@ func (h *Handler) authExportPublicZip(
 	http.ServeContent(w, r, zipName, now, bytes.NewReader(out.Bytes()))
 	return nil
 }
+
+func (h *Handler) authExportPublicJSON(
+	w http.ResponseWriter,
+	r *http.Request,
+	authorities []*client.ExportedAuthority,
+) error {
+	marshalledAuthorities, err := json.Marshal(authorities)
+	if err != nil {
+		return trace.Wrap(err, "failed to JSON marshal authorities")
+	}
+
+	// File name is not critical here. It is only used by `ServeContent` to determine the value of the
+	// `Content-Type` header.
+	http.ServeContent(w, r, "export.json", time.Now(), bytes.NewReader(marshalledAuthorities))
+	return nil
+}

lib/web/ca_export_test.go

@@ -22,6 +22,7 @@ import (
 	"context"
 	"crypto/tls"
 	"crypto/x509"
+	"encoding/json"
 	"encoding/pem"
 	"fmt"
 	"io"
@@ -33,6 +34,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"github.com/gravitational/teleport/lib/client"
 )
 
 func TestAuthExport(t *testing.T) {
@@ -90,6 +93,22 @@ func TestAuthExport(t *testing.T) {
 		validateFormatZip(t, body, wantCAFiles, validateTLSCertificatePEMFunc)
 	}
 
+	validateFormatJSON := func(
+		t *testing.T,
+		body []byte,
+		wantCAFiles int,
+		validateCAFile func(t *testing.T, contents []byte),
+	) {
+		var authorities []client.ExportedAuthority
+		err := json.Unmarshal(body, &authorities)
+		require.NoError(t, err)
+		assert.Len(t, authorities, wantCAFiles)
+
+		for _, authority := range authorities {
+			validateCAFile(t, authority.Data)
+		}
+	}
+
 	ctx := context.Background()
 
 	for _, tt := range []struct {
@@ -215,6 +234,17 @@ func TestAuthExport(t *testing.T) {
 				validateFormatZipPEM(t, b, 1 /* wantCAFiles */)
 			},
 		},
+		{
+			name: "format=json",
+			params: url.Values{
+				"type":   []string{"db-client"},
+				"format": []string{"json"},
+			},
+			expectedStatus: http.StatusOK,
+			assertBody: func(t *testing.T, b []byte) {
+				validateFormatJSON(t, b, 1, validateTLSCertificatePEMFunc)
+			},
+		},
 	} {
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()