Use `hostmatcher` to replace `matchlist`, improve security (#17605)

Use hostmacher to replace matchlist.

And we introduce a better DialContext to do a full host/IP check, otherwise the attackers can still bypass the allow/block list by a 302 redirection.

8 files changed, 93 insertions, 96 deletions

diff --git a/services/migrations/gitea_downloader.go b/services/migrations/gitea_downloader.go
index 00180adf41..258f030726 100644
--- a/services/migrations/gitea_downloader.go
+++ b/services/migrations/gitea_downloader.go
@@ -6,7 +6,6 @@ package migrations
 
 import (
 	"context"
-	"crypto/tls"
 	"errors"
 	"fmt"
 	"io"
@@ -18,8 +17,6 @@ import (
 	admin_model "code.gitea.io/gitea/models/admin"
 	"code.gitea.io/gitea/modules/log"
 	base "code.gitea.io/gitea/modules/migration"
-	"code.gitea.io/gitea/modules/proxy"
-	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 
 	gitea_sdk "code.gitea.io/sdk/gitea"
@@ -90,12 +87,7 @@ func NewGiteaDownloader(ctx context.Context, baseURL, repoPath, username, passwo
 		gitea_sdk.SetToken(token),
 		gitea_sdk.SetBasicAuth(username, password),
 		gitea_sdk.SetContext(ctx),
-		gitea_sdk.SetHTTPClient(&http.Client{
-			Transport: &http.Transport{
-				TLSClientConfig: &tls.Config{InsecureSkipVerify: setting.Migrations.SkipTLSVerify},
-				Proxy:           proxy.Proxy(),
-			},
-		}),
+		gitea_sdk.SetHTTPClient(NewMigrationHTTPClient()),
 	)
 	if err != nil {
 		log.Error(fmt.Sprintf("Failed to create NewGiteaDownloader for: %s. Error: %v", baseURL, err))
@@ -275,12 +267,7 @@ func (g *GiteaDownloader) convertGiteaRelease(rel *gitea_sdk.Release) *base.Rele
 		Created:         rel.CreatedAt,
 	}
 
-	httpClient := &http.Client{
-		Transport: &http.Transport{
-			TLSClientConfig: &tls.Config{InsecureSkipVerify: setting.Migrations.SkipTLSVerify},
-			Proxy:           proxy.Proxy(),
-		},
-	}
+	httpClient := NewMigrationHTTPClient()
 
 	for _, asset := range rel.Attachments {
 		size := int(asset.Size)
diff --git a/services/migrations/gitea_uploader.go b/services/migrations/gitea_uploader.go
index 2394c63d76..d28c83a64f 100644
--- a/services/migrations/gitea_uploader.go
+++ b/services/migrations/gitea_uploader.go
@@ -125,7 +125,7 @@ func (g *GiteaLocalUploader) CreateRepo(repo *base.Repository, opts base.Migrate
 		Wiki:           opts.Wiki,
 		Releases:       opts.Releases, // if didn't get releases, then sync them from tags
 		MirrorInterval: opts.MirrorInterval,
-	})
+	}, NewMigrationHTTPTransport())
 
 	g.repo = r
 	if err != nil {
diff --git a/services/migrations/github.go b/services/migrations/github.go
index 3043d7cf75..b360b05061 100644
--- a/services/migrations/github.go
+++ b/services/migrations/github.go
@@ -7,7 +7,6 @@ package migrations
 
 import (
 	"context"
-	"crypto/tls"
 	"fmt"
 	"io"
 	"net/http"
@@ -19,7 +18,6 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	base "code.gitea.io/gitea/modules/migration"
 	"code.gitea.io/gitea/modules/proxy"
-	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
 
@@ -100,12 +98,7 @@ func NewGithubDownloaderV3(ctx context.Context, baseURL, userName, password, tok
 			)
 			var client = &http.Client{
 				Transport: &oauth2.Transport{
-					Base: &http.Transport{
-						TLSClientConfig: &tls.Config{InsecureSkipVerify: setting.Migrations.SkipTLSVerify},
-						Proxy: func(req *http.Request) (*url.URL, error) {
-							return proxy.Proxy()(req)
-						},
-					},
+					Base:   NewMigrationHTTPTransport(),
 					Source: oauth2.ReuseTokenSource(nil, ts),
 				},
 			}
@@ -113,14 +106,13 @@ func NewGithubDownloaderV3(ctx context.Context, baseURL, userName, password, tok
 			downloader.addClient(client, baseURL)
 		}
 	} else {
+		var transport = NewMigrationHTTPTransport()
+		transport.Proxy = func(req *http.Request) (*url.URL, error) {
+			req.SetBasicAuth(userName, password)
+			return proxy.Proxy()(req)
+		}
 		var client = &http.Client{
-			Transport: &http.Transport{
-				TLSClientConfig: &tls.Config{InsecureSkipVerify: setting.Migrations.SkipTLSVerify},
-				Proxy: func(req *http.Request) (*url.URL, error) {
-					req.SetBasicAuth(userName, password)
-					return proxy.Proxy()(req)
-				},
-			},
+			Transport: transport,
 		}
 		downloader.addClient(client, baseURL)
 	}
@@ -316,12 +308,7 @@ func (g *GithubDownloaderV3) convertGithubRelease(rel *github.RepositoryRelease)
 		r.Published = rel.PublishedAt.Time
 	}
 
-	httpClient := &http.Client{
-		Transport: &http.Transport{
-			TLSClientConfig: &tls.Config{InsecureSkipVerify: setting.Migrations.SkipTLSVerify},
-			Proxy:           proxy.Proxy(),
-		},
-	}
+	httpClient := NewMigrationHTTPClient()
 
 	for _, asset := range rel.Assets {
 		var assetID = *asset.ID // Don't optimize this, for closure we need a local variable
diff --git a/services/migrations/gitlab.go b/services/migrations/gitlab.go
index e285519aa5..4eb7e3e47c 100644
--- a/services/migrations/gitlab.go
+++ b/services/migrations/gitlab.go
@@ -6,7 +6,6 @@ package migrations
 
 import (
 	"context"
-	"crypto/tls"
 	"errors"
 	"fmt"
 	"io"
@@ -18,8 +17,6 @@ import (
 
 	"code.gitea.io/gitea/modules/log"
 	base "code.gitea.io/gitea/modules/migration"
-	"code.gitea.io/gitea/modules/proxy"
-	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 
 	"github.com/xanzy/go-gitlab"
@@ -77,16 +74,11 @@ type GitlabDownloader struct {
 //   Use either a username/password, personal token entered into the username field, or anonymous/public access
 //   Note: Public access only allows very basic access
 func NewGitlabDownloader(ctx context.Context, baseURL, repoPath, username, password, token string) (*GitlabDownloader, error) {
-	gitlabClient, err := gitlab.NewClient(token, gitlab.WithBaseURL(baseURL), gitlab.WithHTTPClient(&http.Client{
-		Transport: &http.Transport{
-			TLSClientConfig: &tls.Config{InsecureSkipVerify: setting.Migrations.SkipTLSVerify},
-			Proxy:           proxy.Proxy(),
-		},
-	}))
+	gitlabClient, err := gitlab.NewClient(token, gitlab.WithBaseURL(baseURL), gitlab.WithHTTPClient(NewMigrationHTTPClient()))
 	// Only use basic auth if token is blank and password is NOT
 	// Basic auth will fail with empty strings, but empty token will allow anonymous public API usage
 	if token == "" && password != "" {
-		gitlabClient, err = gitlab.NewBasicAuthClient(username, password, gitlab.WithBaseURL(baseURL))
+		gitlabClient, err = gitlab.NewBasicAuthClient(username, password, gitlab.WithBaseURL(baseURL), gitlab.WithHTTPClient(NewMigrationHTTPClient()))
 	}
 
 	if err != nil {
@@ -300,12 +292,7 @@ func (g *GitlabDownloader) convertGitlabRelease(rel *gitlab.Release) *base.Relea
 		PublisherName:   rel.Author.Username,
 	}
 
-	httpClient := &http.Client{
-		Transport: &http.Transport{
-			TLSClientConfig: &tls.Config{InsecureSkipVerify: setting.Migrations.SkipTLSVerify},
-			Proxy:           proxy.Proxy(),
-		},
-	}
+	httpClient := NewMigrationHTTPClient()
 
 	for k, asset := range rel.Assets.Links {
 		r.Assets = append(r.Assets, &base.ReleaseAsset{
diff --git a/services/migrations/gogs.go b/services/migrations/gogs.go
index 9473bf8b48..5a477c542d 100644
--- a/services/migrations/gogs.go
+++ b/services/migrations/gogs.go
@@ -6,7 +6,6 @@ package migrations
 
 import (
 	"context"
-	"crypto/tls"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -16,7 +15,6 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	base "code.gitea.io/gitea/modules/migration"
 	"code.gitea.io/gitea/modules/proxy"
-	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 
 	"github.com/gogs/go-gogs-client"
@@ -97,13 +95,12 @@ func NewGogsDownloader(ctx context.Context, baseURL, userName, password, token,
 		client = gogs.NewClient(baseURL, token)
 		downloader.userName = token
 	} else {
-		downloader.transport = &http.Transport{
-			TLSClientConfig: &tls.Config{InsecureSkipVerify: setting.Migrations.SkipTLSVerify},
-			Proxy: func(req *http.Request) (*url.URL, error) {
-				req.SetBasicAuth(userName, password)
-				return proxy.Proxy()(req)
-			},
+		var transport = NewMigrationHTTPTransport()
+		transport.Proxy = func(req *http.Request) (*url.URL, error) {
+			req.SetBasicAuth(userName, password)
+			return proxy.Proxy()(req)
 		}
+		downloader.transport = transport
 
 		client = gogs.NewClient(baseURL, "")
 		client.SetHTTPClient(&http.Client{
diff --git a/services/migrations/http_client.go b/services/migrations/http_client.go
new file mode 100644
index 0000000000..0d683693a1
--- /dev/null
+++ b/services/migrations/http_client.go
@@ -0,0 +1,30 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package migrations
+
+import (
+	"crypto/tls"
+	"net/http"
+
+	"code.gitea.io/gitea/modules/hostmatcher"
+	"code.gitea.io/gitea/modules/proxy"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// NewMigrationHTTPClient returns a HTTP client for migration
+func NewMigrationHTTPClient() *http.Client {
+	return &http.Client{
+		Transport: NewMigrationHTTPTransport(),
+	}
+}
+
+// NewMigrationHTTPTransport returns a HTTP transport for migration
+func NewMigrationHTTPTransport() *http.Transport {
+	return &http.Transport{
+		TLSClientConfig: &tls.Config{InsecureSkipVerify: setting.Migrations.SkipTLSVerify},
+		Proxy:           proxy.Proxy(),
+		DialContext:     hostmatcher.NewDialContext("migration", allowList, blockList),
+	}
+}
diff --git a/services/migrations/migrate.go b/services/migrations/migrate.go
index e6d5e8e4cc..3e805f0b71 100644
--- a/services/migrations/migrate.go
+++ b/services/migrations/migrate.go
@@ -15,8 +15,8 @@ import (
 
 	"code.gitea.io/gitea/models"
 	admin_model "code.gitea.io/gitea/models/admin"
+	"code.gitea.io/gitea/modules/hostmatcher"
 	"code.gitea.io/gitea/modules/log"
-	"code.gitea.io/gitea/modules/matchlist"
 	base "code.gitea.io/gitea/modules/migration"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
@@ -28,8 +28,8 @@ type MigrateOptions = base.MigrateOptions
 var (
 	factories []base.DownloaderFactory
 
-	allowList *matchlist.Matchlist
-	blockList *matchlist.Matchlist
+	allowList *hostmatcher.HostMatchList
+	blockList *hostmatcher.HostMatchList
 )
 
 // RegisterDownloaderFactory registers a downloader factory
@@ -73,30 +73,35 @@ func IsMigrateURLAllowed(remoteURL string, doer *models.User) error {
 		return &models.ErrInvalidCloneAddr{Host: u.Host, IsProtocolInvalid: true, IsPermissionDenied: true, IsURLError: true}
 	}
 
-	host := strings.ToLower(u.Host)
-	if len(setting.Migrations.AllowedDomains) > 0 {
-		if !allowList.Match(host) {
-			return &models.ErrInvalidCloneAddr{Host: u.Host, IsPermissionDenied: true}
-		}
-	} else {
-		if blockList.Match(host) {
-			return &models.ErrInvalidCloneAddr{Host: u.Host, IsPermissionDenied: true}
-		}
+	hostName, _, err := net.SplitHostPort(u.Host)
+	if err != nil {
+		// u.Host can be "host" or "host:port"
+		err = nil //nolint
+		hostName = u.Host
+	}
+	addrList, err := net.LookupIP(hostName)
+	if err != nil {
+		return &models.ErrInvalidCloneAddr{Host: u.Host, NotResolvedIP: true}
 	}
 
-	if !setting.Migrations.AllowLocalNetworks {
-		addrList, err := net.LookupIP(strings.Split(u.Host, ":")[0])
-		if err != nil {
-			return &models.ErrInvalidCloneAddr{Host: u.Host, NotResolvedIP: true}
-		}
-		for _, addr := range addrList {
-			if util.IsIPPrivate(addr) || !addr.IsGlobalUnicast() {
-				return &models.ErrInvalidCloneAddr{Host: u.Host, PrivateNet: addr.String(), IsPermissionDenied: true}
-			}
+	var ipAllowed bool
+	var ipBlocked bool
+	for _, addr := range addrList {
+		ipAllowed = ipAllowed || allowList.MatchIPAddr(addr)
+		ipBlocked = ipBlocked || blockList.MatchIPAddr(addr)
+	}
+	var blockedError error
+	if blockList.MatchHostName(hostName) || ipBlocked {
+		blockedError = &models.ErrInvalidCloneAddr{Host: u.Host, IsPermissionDenied: true}
+	}
+	// if we have an allow-list, check the allow-list first
+	if !allowList.IsEmpty() {
+		if !allowList.MatchHostName(hostName) && !ipAllowed {
+			return &models.ErrInvalidCloneAddr{Host: u.Host, IsPermissionDenied: true}
 		}
 	}
-
-	return nil
+	// otherwise, we always follow the blocked list
+	return blockedError
 }
 
 // MigrateRepository migrate repository according MigrateOptions
@@ -462,16 +467,18 @@ func migrateRepository(downloader base.Downloader, uploader base.Uploader, opts
 
 // Init migrations service
 func Init() error {
-	var err error
-	allowList, err = matchlist.NewMatchlist(setting.Migrations.AllowedDomains...)
-	if err != nil {
-		return fmt.Errorf("init migration allowList domains failed: %v", err)
-	}
+	// TODO: maybe we can deprecate these legacy ALLOWED_DOMAINS/ALLOW_LOCALNETWORKS/BLOCKED_DOMAINS, use ALLOWED_HOST_LIST/BLOCKED_HOST_LIST instead
 
-	blockList, err = matchlist.NewMatchlist(setting.Migrations.BlockedDomains...)
-	if err != nil {
-		return fmt.Errorf("init migration blockList domains failed: %v", err)
-	}
+	blockList = hostmatcher.ParseSimpleMatchList("migrations.BLOCKED_DOMAINS", setting.Migrations.BlockedDomains)
 
+	allowList = hostmatcher.ParseSimpleMatchList("migrations.ALLOWED_DOMAINS/ALLOW_LOCALNETWORKS", setting.Migrations.AllowedDomains)
+	if allowList.IsEmpty() {
+		// the default policy is that migration module can access external hosts
+		allowList.AppendBuiltin(hostmatcher.MatchBuiltinExternal)
+	}
+	if setting.Migrations.AllowLocalNetworks {
+		allowList.AppendBuiltin(hostmatcher.MatchBuiltinPrivate)
+		allowList.AppendBuiltin(hostmatcher.MatchBuiltinLoopback)
+	}
 	return nil
 }
diff --git a/services/migrations/migrate_test.go b/services/migrations/migrate_test.go
index 325064697e..e2363242a2 100644
--- a/services/migrations/migrate_test.go
+++ b/services/migrations/migrate_test.go
@@ -21,7 +21,8 @@ func TestMigrateWhiteBlocklist(t *testing.T) {
 	adminUser := unittest.AssertExistsAndLoadBean(t, &models.User{Name: "user1"}).(*models.User)
 	nonAdminUser := unittest.AssertExistsAndLoadBean(t, &models.User{Name: "user2"}).(*models.User)
 
-	setting.Migrations.AllowedDomains = []string{"github.com"}
+	setting.Migrations.AllowedDomains = "github.com"
+	setting.Migrations.AllowLocalNetworks = false
 	assert.NoError(t, Init())
 
 	err := IsMigrateURLAllowed("https://gitlab.com/gitlab/gitlab.git", nonAdminUser)
@@ -33,8 +34,8 @@ func TestMigrateWhiteBlocklist(t *testing.T) {
 	err = IsMigrateURLAllowed("https://gITHUb.com/go-gitea/gitea.git", nonAdminUser)
 	assert.NoError(t, err)
 
-	setting.Migrations.AllowedDomains = []string{}
-	setting.Migrations.BlockedDomains = []string{"github.com"}
+	setting.Migrations.AllowedDomains = ""
+	setting.Migrations.BlockedDomains = "github.com"
 	assert.NoError(t, Init())
 
 	err = IsMigrateURLAllowed("https://gitlab.com/gitlab/gitlab.git", nonAdminUser)
@@ -47,6 +48,7 @@ func TestMigrateWhiteBlocklist(t *testing.T) {
 	assert.Error(t, err)
 
 	setting.Migrations.AllowLocalNetworks = true
+	assert.NoError(t, Init())
 	err = IsMigrateURLAllowed("https://10.0.0.1/go-gitea/gitea.git", nonAdminUser)
 	assert.NoError(t, err)