| 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, "status", "--porcelain=v1") |
| 26 | for _, want := range []string{"core.fsmonitor=false", "maintenance.auto=false"} { |
| 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] != "status" || got[1] != "--porcelain=v1" { |
| 36 | t.Fatalf("trailing args = %v, want the caller's arguments last", got) |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | // Extra config may add to the baseline but must never replace it: a call site |
| 41 | // that wants its own preference still gets the hardening. |
| 42 | func TestArgsExtraConfigCannotDropBaseline(t *testing.T) { |
| 43 | args := argsFor("linux", "/repo", []string{"core.quotepath=false", ""}, "status") |
| 44 | if !hasConfig(args, "core.fsmonitor=false") { |
| 45 | t.Fatalf("args = %v, want the baseline retained alongside extra config", args) |
| 46 | } |
| 47 | if !hasConfig(args, "core.quotepath=false") { |
| 48 | t.Fatalf("args = %v, want the extra config applied", args) |
| 49 | } |
| 50 | base := slices.Index(args, "core.fsmonitor=false") |
| 51 | extra := slices.Index(args, "core.quotepath=false") |
| 52 | if base > extra { |
| 53 | t.Fatalf("args = %v, want baseline before extra config so the caller's value wins ties", args) |
| 54 | } |
| 55 | if slices.Contains(args, "") { |
| 56 | t.Fatalf("args = %v, want empty config entries dropped", args) |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | func TestArgsEnableLongPathsOnlyOnWindows(t *testing.T) { |
| 61 | if args := argsFor("windows", `C:\Users\test\repo`, nil, "status"); !hasConfig(args, "core.longpaths=true") { |
| 62 | t.Fatalf("windows args = %v, want core.longpaths=true", args) |
| 63 | } |
| 64 | if args := argsFor("linux", "/tmp/repo", nil, "status"); hasConfig(args, "core.longpaths=true") { |
| 65 | t.Fatalf("non-windows args = %v, must not override core.longpaths", args) |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | // diff is the one subcommand that can be pointed at an external program by |
| 70 | // repository configuration, so it carries the disabling flags — placed after |
| 71 | // the subcommand, never duplicated, and never added to other subcommands. |
| 72 | func TestDiffDisablesRepositoryConfiguredPrograms(t *testing.T) { |
| 73 | args := argsFor("linux", "/repo", nil, "diff", "--numstat", "HEAD", "--") |
| 74 | sub := slices.Index(args, "diff") |
| 75 | if sub < 0 { |
| 76 | t.Fatalf("args = %v, want the diff subcommand", args) |
| 77 | } |
| 78 | for _, flag := range []string{"--no-ext-diff", "--no-textconv"} { |
| 79 | i := slices.Index(args, flag) |
| 80 | if i < 0 { |
| 81 | t.Fatalf("args = %v, want %s", args, flag) |
| 82 | } |
| 83 | if i < sub { |
| 84 | t.Fatalf("args = %v, want %s after the subcommand", args, flag) |
| 85 | } |
| 86 | } |
| 87 | if got := args[len(args)-3:]; got[0] != "--numstat" || got[1] != "HEAD" || got[2] != "--" { |
| 88 | t.Fatalf("trailing args = %v, want the caller's diff arguments preserved in order", got) |
| 89 | } |
| 90 | |
| 91 | explicit := argsFor("linux", "/repo", nil, "diff", "--no-ext-diff", "HEAD") |
| 92 | if n := strings.Count(strings.Join(explicit, " "), "--no-ext-diff"); n != 1 { |
| 93 | t.Fatalf("args = %v, want one --no-ext-diff when the caller already passed it", explicit) |
| 94 | } |
| 95 | |
| 96 | if args := argsFor("linux", "/repo", nil, "status"); slices.Contains(args, "--no-ext-diff") { |
| 97 | t.Fatalf("status args = %v, must not carry diff-only flags", args) |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | func TestEnvDisablesPromptsAndKeepsSSHUsable(t *testing.T) { |
| 102 | env := Env() |
| 103 | if !slices.Contains(env, "GIT_OPTIONAL_LOCKS=0") || !slices.Contains(env, "GIT_TERMINAL_PROMPT=0") { |
| 104 | t.Fatalf("env = %v, want optional locks and terminal prompts disabled", env) |
| 105 | } |
| 106 | // An empty value is a *present* value to git: clearing these would break |
| 107 | // legitimate ssh remotes and external diff tooling rather than harden. |
| 108 | for _, banned := range []string{"GIT_SSH_COMMAND=", "GIT_EXTERNAL_DIFF="} { |
| 109 | if slices.Contains(env, banned) { |
| 110 | t.Fatalf("env = %v, must not set %q", env, banned) |
| 111 | } |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | // The invariant this package exists for: a repository's own config names a |
| 116 | // command in core.fsmonitor, and inspecting that repository must not run it. |
| 117 | // git executes fsmonitor during an index refresh, which a plain status does. |
| 118 | func TestRepositoryConfigCannotRunCommandsDuringInspection(t *testing.T) { |
| 119 | if runtime.GOOS == "windows" { |
| 120 | t.Skip("payload script is POSIX shell") |
| 121 | } |
| 122 | if _, err := exec.LookPath("git"); err != nil { |
| 123 | t.Skip("git not installed") |
| 124 | } |
| 125 | |
| 126 | repo := t.TempDir() |
| 127 | ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second) |
| 128 | defer cancel() |
| 129 | |
| 130 | run := func(args ...string) { |
| 131 | t.Helper() |
| 132 | if out, err := Command(ctx, repo, args...).CombinedOutput(); err != nil { |
| 133 | t.Fatalf("git %v: %v: %s", args, err, out) |
| 134 | } |
| 135 | } |
| 136 | run("init", "--quiet") |
| 137 | run("config", "user.email", "test@example.com") |
| 138 | run("config", "user.name", "test") |
| 139 | if err := os.WriteFile(filepath.Join(repo, "file.txt"), []byte("content\n"), 0o600); err != nil { |
| 140 | t.Fatal(err) |
| 141 | } |
| 142 | run("add", "file.txt") |
| 143 | run("commit", "--quiet", "-m", "initial") |
| 144 | |
| 145 | // A repository whose config points fsmonitor at a command. Writing the |
| 146 | // marker is what an attacker's payload would do first. |
| 147 | marker := filepath.Join(t.TempDir(), "executed") |
| 148 | payload := filepath.Join(t.TempDir(), "payload.sh") |
| 149 | script := "#!/bin/sh\ntouch " + marker + "\nexit 1\n" |
| 150 | if err := os.WriteFile(payload, []byte(script), 0o700); err != nil { |
| 151 | t.Fatal(err) |
| 152 | } |
| 153 | run("config", "core.fsmonitor", payload) |
| 154 | |
| 155 | // Dirty the tree so an index refresh has work to do, then inspect it the |
| 156 | // way the status readout does. |
| 157 | if err := os.WriteFile(filepath.Join(repo, "file.txt"), []byte("changed\n"), 0o600); err != nil { |
| 158 | t.Fatal(err) |
| 159 | } |
| 160 | _, _ = Command(ctx, repo, "status", "--porcelain=v1").CombinedOutput() |
| 161 | _, _ = Command(ctx, repo, "diff", "--numstat", "HEAD", "--").CombinedOutput() |
| 162 | _, _ = Command(ctx, repo, "rev-parse", "--show-toplevel").CombinedOutput() |
| 163 | |
| 164 | if _, err := os.Stat(marker); err == nil { |
| 165 | t.Fatal("repository config ran a command during inspection") |
| 166 | } else if !os.IsNotExist(err) { |
| 167 | t.Fatalf("stat marker: %v", err) |
| 168 | } |
| 169 | } |
| 170 |