Add ability to scan snaps (as a source) (#3929)

internal/file/getter_test.go

@@ -0,0 +1,268 @@
+package file
+
+import (
+	"archive/tar"
+	"bytes"
+	"context"
+	"crypto/x509"
+	"fmt"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"path"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/anchore/clio"
+)
+
+func TestGetter_GetFile(t *testing.T) {
+	testCases := []struct {
+		name          string
+		prepareClient func(*http.Client)
+		assert        assert.ErrorAssertionFunc
+	}{
+		{
+			name:   "client trusts server's CA",
+			assert: assert.NoError,
+		},
+		{
+			name:          "client doesn't trust server's CA",
+			prepareClient: removeTrustedCAs,
+			assert:        assertUnknownAuthorityError,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			requestPath := "/foo"
+
+			server := newTestServer(t, withResponseForPath(t, requestPath, testFileContent))
+			t.Cleanup(server.Close)
+
+			httpClient := getClient(t, server)
+			if tc.prepareClient != nil {
+				tc.prepareClient(httpClient)
+			}
+
+			getter := NewGetter(testID, httpClient)
+			requestURL := createRequestURL(t, server, requestPath)
+
+			tempDir := t.TempDir()
+			tempFile := path.Join(tempDir, "some-destination-file")
+
+			err := getter.GetFile(tempFile, requestURL)
+			tc.assert(t, err)
+		})
+	}
+}
+
+func TestGetter_GetToDir_FilterNonArchivesWired(t *testing.T) {
+	testCases := []struct {
+		name   string
+		source string
+		assert assert.ErrorAssertionFunc
+	}{
+		{
+			name:   "error out on non-archive sources",
+			source: "http://localhost/something.txt",
+			assert: assertErrNonArchiveSource,
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.name, func(t *testing.T) {
+			test.assert(t, NewGetter(testID, nil).GetToDir(t.TempDir(), test.source))
+		})
+	}
+}
+
+func TestGetter_validateHttpSource(t *testing.T) {
+	testCases := []struct {
+		name   string
+		source string
+		assert assert.ErrorAssertionFunc
+	}{
+		{
+			name:   "error out on non-archive sources",
+			source: "http://localhost/something.txt",
+			assert: assertErrNonArchiveSource,
+		},
+		{
+			name:   "filter out non-archive sources with get param",
+			source: "https://localhost/vulnerability-db_v3_2021-11-21T08:15:44Z.txt?checksum=sha256%3Ac402d01fa909a3fa85a5c6733ef27a3a51a9105b6c62b9152adbd24c08358911",
+			assert: assertErrNonArchiveSource,
+		},
+		{
+			name:   "ignore non http-https input",
+			source: "s3://bucket/something.txt",
+			assert: assert.NoError,
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.name, func(t *testing.T) {
+			test.assert(t, validateHTTPSource(test.source))
+		})
+	}
+}
+
+func TestGetter_GetToDir_CertConcerns(t *testing.T) {
+	testCases := []struct {
+		name          string
+		prepareClient func(*http.Client)
+		assert        assert.ErrorAssertionFunc
+	}{
+
+		{
+			name:   "client trusts server's CA",
+			assert: assert.NoError,
+		},
+		{
+			name:          "client doesn't trust server's CA",
+			prepareClient: removeTrustedCAs,
+			assert:        assertUnknownAuthorityError,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			requestPath := "/foo.tar"
+			tarball := createTarball("foo", testFileContent)
+
+			server := newTestServer(t, withResponseForPath(t, requestPath, tarball))
+			t.Cleanup(server.Close)
+
+			httpClient := getClient(t, server)
+			if tc.prepareClient != nil {
+				tc.prepareClient(httpClient)
+			}
+
+			getter := NewGetter(testID, httpClient)
+			requestURL := createRequestURL(t, server, requestPath)
+
+			tempDir := t.TempDir()
+
+			err := getter.GetToDir(tempDir, requestURL)
+			tc.assert(t, err)
+		})
+	}
+}
+
+func assertUnknownAuthorityError(t assert.TestingT, err error, _ ...interface{}) bool {
+	return assert.ErrorAs(t, err, &x509.UnknownAuthorityError{})
+}
+
+func assertErrNonArchiveSource(t assert.TestingT, err error, _ ...interface{}) bool {
+	return assert.ErrorIs(t, err, ErrNonArchiveSource)
+}
+
+func removeTrustedCAs(client *http.Client) {
+	client.Transport.(*http.Transport).TLSClientConfig.RootCAs = x509.NewCertPool()
+}
+
+// createTarball makes a single-file tarball and returns it as a byte slice.
+func createTarball(filename string, content []byte) []byte {
+	tarBuffer := new(bytes.Buffer)
+	tarWriter := tar.NewWriter(tarBuffer)
+	tarWriter.WriteHeader(&tar.Header{
+		Name: filename,
+		Size: int64(len(content)),
+		Mode: 0600,
+	})
+	tarWriter.Write(content)
+	tarWriter.Close()
+
+	return tarBuffer.Bytes()
+}
+
+type muxOption func(mux *http.ServeMux)
+
+func withResponseForPath(t *testing.T, path string, response []byte) muxOption {
+	t.Helper()
+
+	return func(mux *http.ServeMux) {
+		mux.HandleFunc(path, func(w http.ResponseWriter, req *http.Request) {
+			t.Logf("server handling request: %s %s", req.Method, req.URL)
+
+			_, err := w.Write(response)
+			if err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}
+
+var testID = clio.Identification{
+	Name:    "test-app",
+	Version: "v0.5.3",
+}
+
+func newTestServer(t *testing.T, muxOptions ...muxOption) *httptest.Server {
+	t.Helper()
+
+	mux := http.NewServeMux()
+	for _, option := range muxOptions {
+		option(mux)
+	}
+
+	server := httptest.NewTLSServer(mux)
+	t.Logf("new TLS server listening at %s", getHost(t, server))
+
+	return server
+}
+
+func createRequestURL(t *testing.T, server *httptest.Server, path string) string {
+	t.Helper()
+
+	// TODO: Figure out how to get this value from the server without hardcoding it here
+	const testServerCertificateName = "example.com"
+
+	serverURL, err := url.Parse(server.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Set URL hostname to value from TLS certificate
+	serverURL.Host = fmt.Sprintf("%s:%s", testServerCertificateName, serverURL.Port())
+
+	serverURL.Path = path
+
+	return serverURL.String()
+}
+
+// getClient returns an http.Client that can be used to contact the test TLS server.
+func getClient(t *testing.T, server *httptest.Server) *http.Client {
+	t.Helper()
+
+	httpClient := server.Client()
+	transport := httpClient.Transport.(*http.Transport)
+
+	serverHost := getHost(t, server)
+
+	transport.DialContext = func(_ context.Context, _, addr string) (net.Conn, error) {
+		t.Logf("client dialing %q for host %q", serverHost, addr)
+
+		// Ensure the client dials our test server
+		return net.Dial("tcp", serverHost)
+	}
+
+	return httpClient
+}
+
+// getHost extracts the host value from a server URL string.
+// e.g. given a server with URL "http://1.2.3.4:5000/foo", getHost returns "1.2.3.4:5000"
+func getHost(t *testing.T, server *httptest.Server) string {
+	t.Helper()
+
+	u, err := url.Parse(server.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return u.Hostname() + ":" + u.Port()
+}
+
+var testFileContent = []byte("This is the content of a test file!\n")