| 1 | package gitcmd |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "os" |
| 6 | "os/exec" |
| 7 | "path/filepath" |
| 8 | "runtime" |
| 9 | "slices" |
| 10 | "strings" |
| 11 | "testing" |
| 12 | "time" |
| 13 | ) |
| 14 | |
| 15 | func hasConfig(args []string, want string) bool { |
| 16 | for i := 0; i+1 < len(args); i++ { |
| 17 | if args[i] == "-c" && args[i+1] == want { |
| 18 | return true |
| 19 | } |
| 20 | } |
| 21 | return false |
| 22 | } |
| 23 | |
| 24 | func TestArgsCarryBaselineConfig(t *testing.T) { |
| 25 | args := argsFor("linux", "/repo", nil, "rev-parse", "--show-toplevel") |
| 26 | for _, want := range []string{"core.fsmonitor=", "maintenance.auto=false", "gc.auto=0", "core.hooksPath=" + os.DevNull, "log.showSignature=false", "merge.verifySignatures=false", "diff.submodule=short", "safe.bareRepository=explicit"} { |
| 27 | if !hasConfig(args, want) { |
| 28 | t.Fatalf("args = %v, want -c %s", args, want) |
| 29 | } |
| 30 | } |
| 31 | if i := slices.Index(args, "-C"); i < 0 || args[i+1] != "/repo" { |
| 32 | t.Fatalf("args = %v, want -C /repo", args) |
| 33 | } |
| 34 | // Caller arguments stay last and in order. |
| 35 | if got := args[len(args)-2:]; got[0] != "rev-parse" || got[1] != "--show-toplevel" { |
| 36 | t.Fatalf("trailing args = %v, want the caller's arguments last", got) |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | // A user's own submodule.recurse=true never carries a host checkout, merge or |
| 41 | // reset into a submodule; other subcommands leave that choice alone. |
| 42 | func TestArgsPinSubmoduleRecurseForTreeUpdates(t *testing.T) { |
| 43 | for _, sub := range []string{"checkout", "switch", "restore", "reset", "merge", "read-tree"} { |
| 44 | if args := argsFor("linux", "/repo", nil, sub); !hasConfig(args, "submodule.recurse=false") { |
| 45 | t.Fatalf("%s args = %v, want submodule.recurse=false", sub, args) |
| 46 | } |
| 47 | } |
| 48 | if args := argsFor("linux", "/repo", nil, "status"); hasConfig(args, "submodule.recurse=false") { |
| 49 | t.Fatalf("status args = %v, want the user's submodule.recurse left alone", args) |
| 50 | } |
| 51 | } |
| 52 | |
| 53 | // Extra config may add to the baseline but must never replace it: a call site |
| 54 | // that wants its own preference still gets the hardening. |
| 55 | func TestArgsExtraConfigCannotDropBaseline(t *testing.T) { |
| 56 | args := argsFor("linux", "/repo", []string{"core.quotepath=false", ""}, "status") |
| 57 | if !hasConfig(args, "core.fsmonitor=") { |
| 58 | t.Fatalf("args = %v, want the baseline retained alongside extra config", args) |
| 59 | } |
| 60 | if !hasConfig(args, "core.quotepath=false") { |
| 61 | t.Fatalf("args = %v, want the extra config applied", args) |
| 62 | } |
| 63 | base := slices.Index(args, "core.fsmonitor=") |
| 64 | extra := slices.Index(args, "core.quotepath=false") |
| 65 | if base > extra { |
| 66 | t.Fatalf("args = %v, want baseline before extra config so the caller's value wins ties", args) |
| 67 | } |
| 68 | if slices.Contains(args, "") { |
| 69 | t.Fatalf("args = %v, want empty config entries dropped", args) |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | func TestArgsEnableLongPathsOnlyOnWindows(t *testing.T) { |
| 74 | if args := argsFor("windows", `C:\Users\test\repo`, nil, "status"); !hasConfig(args, "core.longpaths=true") { |
| 75 | t.Fatalf("windows args = %v, want core.longpaths=true", args) |
| 76 | } |
| 77 | if args := argsFor("linux", "/tmp/repo", nil, "status"); hasConfig(args, "core.longpaths=true") { |
| 78 | t.Fatalf("non-windows args = %v, must not override core.longpaths", args) |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | // The disabling flags go right after the subcommand — found past any global |
| 83 | // options the caller put in args — and are never duplicated. |
| 84 | func TestSubcommandFlagsDisableRepositoryConfiguredPrograms(t *testing.T) { |
| 85 | for _, tt := range []struct { |
| 86 | args []string |
| 87 | want []string |
| 88 | not []string |
| 89 | }{ |
| 90 | {[]string{"diff", "--numstat", "HEAD", "--"}, []string{"diff", "--no-ext-diff", "--no-textconv", "--ignore-submodules=dirty", "--numstat", "HEAD", "--"}, nil}, |
| 91 | {[]string{"-C", "/r", "diff", "HEAD"}, []string{"-C", "/r", "diff", "--no-ext-diff", "--no-textconv", "--ignore-submodules=dirty", "HEAD"}, nil}, |
| 92 | {[]string{"-c", "user.name=x", "log", "-p"}, []string{"-c", "user.name=x", "log", "--no-ext-diff", "--no-textconv", "-p"}, []string{"--ignore-submodules=dirty"}}, |
| 93 | {[]string{"--git-dir=/g", "show", "HEAD"}, []string{"--git-dir=/g", "show", "--no-ext-diff", "--no-textconv", "HEAD"}, nil}, |
| 94 | {[]string{"-C", "/r", "status", "--porcelain=v1"}, []string{"-C", "/r", "status", "--ignore-submodules=dirty", "--porcelain=v1"}, []string{"--no-ext-diff"}}, |
| 95 | {[]string{"diff", "--no-ext-diff", "--ignore-submodules=all"}, []string{"diff", "--no-textconv", "--no-ext-diff", "--ignore-submodules=all"}, nil}, |
| 96 | {[]string{"rev-parse", "--show-toplevel"}, []string{"rev-parse", "--show-toplevel"}, nil}, |
| 97 | {[]string{"--version"}, []string{"--version"}, nil}, |
| 98 | } { |
| 99 | got := hardenSubcommand(tt.args) |
| 100 | if !slices.Equal(got, tt.want) { |
| 101 | t.Fatalf("hardenSubcommand(%v) = %v, want %v", tt.args, got, tt.want) |
| 102 | } |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | func TestDetachedRunsOutsideAnyRepository(t *testing.T) { |
| 107 | requirePOSIXGit(t) |
| 108 | f := newRepoFixture(t, "", map[string]string{"f.txt": "x\n"}) |
| 109 | t.Chdir(f.dir) |
| 110 | cmd := exec.Command("git", "rev-parse", "--git-dir") |
| 111 | cmd.Env = append(os.Environ(), "GIT_DIR="+filepath.Join(f.dir, ".git")) |
| 112 | cleanup, err := Detached(cmd) |
| 113 | if err != nil { |
| 114 | t.Fatal(err) |
| 115 | } |
| 116 | defer cleanup() |
| 117 | if out, err := cmd.CombinedOutput(); err == nil { |
| 118 | t.Fatalf("rev-parse in a detached command found a repository: %s", out) |
| 119 | } |
| 120 | if slices.Contains(cmd.Env, "GIT_DIR="+filepath.Join(f.dir, ".git")) { |
| 121 | t.Fatalf("env = %v, want GIT_DIR dropped", cmd.Env) |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | func TestEnvDisablesPromptsAndKeepsSSHUsable(t *testing.T) { |
| 126 | env := Env() |
| 127 | if !slices.Contains(env, "GIT_OPTIONAL_LOCKS=0") || !slices.Contains(env, "GIT_TERMINAL_PROMPT=0") || !slices.Contains(env, "GIT_NO_LAZY_FETCH=1") { |
| 128 | t.Fatalf("env = %v, want optional locks and terminal prompts disabled", env) |
| 129 | } |
| 130 | // An empty value is a *present* value to git: clearing these would break |
| 131 | // legitimate ssh remotes and external diff tooling rather than harden. |
| 132 | for _, banned := range []string{"GIT_SSH_COMMAND=", "GIT_EXTERNAL_DIFF="} { |
| 133 | if slices.Contains(env, banned) { |
| 134 | t.Fatalf("env = %v, must not set %q", env, banned) |
| 135 | } |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | // The invariant this package exists for: a repository's own config names a |
| 140 | // command in core.fsmonitor, and inspecting that repository must not run it. |
| 141 | // git executes fsmonitor during an index refresh, which a plain status does. |
| 142 | func TestRepositoryConfigCannotRunCommandsDuringInspection(t *testing.T) { |
| 143 | if runtime.GOOS == "windows" { |
| 144 | t.Skip("payload script is POSIX shell") |
| 145 | } |
| 146 | if _, err := exec.LookPath("git"); err != nil { |
| 147 | t.Skip("git not installed") |
| 148 | } |
| 149 | |
| 150 | repo := t.TempDir() |
| 151 | ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second) |
| 152 | defer cancel() |
| 153 | |
| 154 | run := func(args ...string) { |
| 155 | t.Helper() |
| 156 | if out, err := Command(ctx, repo, args...).CombinedOutput(); err != nil { |
| 157 | t.Fatalf("git %v: %v: %s", args, err, out) |
| 158 | } |
| 159 | } |
| 160 | run("init", "--quiet") |
| 161 | run("config", "user.email", "test@example.com") |
| 162 | run("config", "user.name", "test") |
| 163 | if err := os.WriteFile(filepath.Join(repo, "file.txt"), []byte("content\n"), 0o600); err != nil { |
| 164 | t.Fatal(err) |
| 165 | } |
| 166 | run("add", "file.txt") |
| 167 | run("commit", "--quiet", "-m", "initial") |
| 168 | |
| 169 | // A repository whose config points fsmonitor at a command. Writing the |
| 170 | // marker is what an attacker's payload would do first. |
| 171 | marker := filepath.Join(t.TempDir(), "executed") |
| 172 | payload := filepath.Join(t.TempDir(), "payload.sh") |
| 173 | script := "#!/bin/sh\ntouch " + marker + "\nexit 1\n" |
| 174 | if err := os.WriteFile(payload, []byte(script), 0o700); err != nil { |
| 175 | t.Fatal(err) |
| 176 | } |
| 177 | run("config", "core.fsmonitor", payload) |
| 178 | |
| 179 | // Dirty the tree so an index refresh has work to do, then inspect it the |
| 180 | // way the status readout does. |
| 181 | if err := os.WriteFile(filepath.Join(repo, "file.txt"), []byte("changed\n"), 0o600); err != nil { |
| 182 | t.Fatal(err) |
| 183 | } |
| 184 | _, _ = Command(ctx, repo, "status", "--porcelain=v1").CombinedOutput() |
| 185 | _, _ = Command(ctx, repo, "diff", "--numstat", "HEAD", "--").CombinedOutput() |
| 186 | _, _ = Command(ctx, repo, "rev-parse", "--show-toplevel").CombinedOutput() |
| 187 | |
| 188 | if _, err := os.Stat(marker); err == nil { |
| 189 | t.Fatal("repository config ran a command during inspection") |
| 190 | } else if !os.IsNotExist(err) { |
| 191 | t.Fatalf("stat marker: %v", err) |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | // The clean-filter residual from the advisory: a .gitattributes entry plus a |
| 196 | // filter.<driver>.clean command in the repository's local config makes |
| 197 | // `git diff` run that command to produce the "clean" working-tree side, and |
| 198 | // neither --no-ext-diff nor --no-textconv covers it. Diff invocations must |
| 199 | // neutralize every locally-defined driver while still rendering a correct |
| 200 | // diff (the emptied filter is an identity pass-through, not a content wipe). |
| 201 | func TestDiffDoesNotRunRepositoryCleanFilters(t *testing.T) { |
| 202 | if runtime.GOOS == "windows" { |
| 203 | t.Skip("payload script is POSIX shell") |
| 204 | } |
| 205 | if _, err := exec.LookPath("git"); err != nil { |
| 206 | t.Skip("git not installed") |
| 207 | } |
| 208 | |
| 209 | repo := t.TempDir() |
| 210 | ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second) |
| 211 | defer cancel() |
| 212 | |
| 213 | run := func(args ...string) { |
| 214 | t.Helper() |
| 215 | if out, err := Command(ctx, repo, args...).CombinedOutput(); err != nil { |
| 216 | t.Fatalf("git %v: %v: %s", args, err, out) |
| 217 | } |
| 218 | } |
| 219 | run("init", "--quiet") |
| 220 | run("config", "user.email", "test@example.com") |
| 221 | run("config", "user.name", "test") |
| 222 | |
| 223 | marker := filepath.Join(t.TempDir(), "executed") |
| 224 | payload := filepath.Join(t.TempDir(), "clean.sh") |
| 225 | script := "#!/bin/sh\ntouch " + marker + "\ncat\n" |
| 226 | if err := os.WriteFile(payload, []byte(script), 0o700); err != nil { |
| 227 | t.Fatal(err) |
| 228 | } |
| 229 | if err := os.WriteFile(filepath.Join(repo, ".gitattributes"), []byte("secret.bin filter=pwn\n"), 0o600); err != nil { |
| 230 | t.Fatal(err) |
| 231 | } |
| 232 | if err := os.WriteFile(filepath.Join(repo, "secret.bin"), []byte("secret\n"), 0o600); err != nil { |
| 233 | t.Fatal(err) |
| 234 | } |
| 235 | run("add", ".gitattributes", "secret.bin") |
| 236 | run("commit", "--quiet", "-m", "initial") |
| 237 | run("config", "filter.pwn.clean", payload) |
| 238 | run("config", "filter.pwn.process", payload) |
| 239 | run("config", "filter.pwn.required", "true") |
| 240 | if err := os.WriteFile(filepath.Join(repo, "secret.bin"), []byte("secret\nchanged\n"), 0o600); err != nil { |
| 241 | t.Fatal(err) |
| 242 | } |
| 243 | |
| 244 | // The exact shape desktop/workspace_changes.go builds: -C inside args. |
| 245 | out, err := Command(ctx, "", "-C", repo, "diff", "--no-ext-diff", "--no-textconv", "--relative", "HEAD", "--", filepath.FromSlash("secret.bin")).CombinedOutput() |
| 246 | if err != nil { |
| 247 | t.Fatalf("diff failed: %v: %s", err, out) |
| 248 | } |
| 249 | if !strings.Contains(string(out), "changed") { |
| 250 | t.Fatalf("diff output lost the working-tree change (filter neutralization must pass content through):\n%s", out) |
| 251 | } |
| 252 | // And the shape internal/cli/gitstatus.go builds: dir parameter + diff. |
| 253 | if out, err = Command(ctx, repo, "diff", "--numstat", "HEAD", "--").CombinedOutput(); err != nil { |
| 254 | t.Fatalf("numstat diff failed: %v: %s", err, out) |
| 255 | } |
| 256 | |
| 257 | if _, err := os.Stat(marker); err == nil { |
| 258 | t.Fatal("repository clean filter ran during a diff") |
| 259 | } else if !os.IsNotExist(err) { |
| 260 | t.Fatalf("stat marker: %v", err) |
| 261 | } |
| 262 | } |
| 263 |