root_linux_test.go

     1  // Copyright 2025 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build linux
     6  
     7  package x509
     8  
     9  import (
    10  	"encoding/pem"
    11  	"fmt"
    12  	"internal/testenv"
    13  	"os"
    14  	"os/exec"
    15  	"syscall"
    16  	"testing"
    17  )
    18  
    19  func TestSetFallbackRoots(t *testing.T) {
    20  	if testing.Short() {
    21  		t.Skip("skipping test in short mode")
    22  	}
    23  	testenv.MustHaveExec(t)
    24  
    25  	test := func(t *testing.T, name string, f func(t *testing.T)) {
    26  		t.Run(name, func(t *testing.T) {
    27  			if os.Getenv("CRYPTO_X509_SETFALLBACKROOTS_TEST") != "1" {
    28  				// Execute test in a separate process with CRYPTO_X509_SETFALBACKROOTS_TEST env.
    29  				cmd := exec.Command(os.Args[0], fmt.Sprintf("-test.run=^%v$", t.Name()))
    30  				cmd.Env = append(os.Environ(), "CRYPTO_X509_SETFALLBACKROOTS_TEST=1")
    31  				cmd.SysProcAttr = &syscall.SysProcAttr{
    32  					Cloneflags:  syscall.CLONE_NEWNS | syscall.CLONE_NEWUSER,
    33  					UidMappings: []syscall.SysProcIDMap{{ContainerID: 0, HostID: os.Getuid(), Size: 1}},
    34  					GidMappings: []syscall.SysProcIDMap{{ContainerID: 0, HostID: os.Getgid(), Size: 1}},
    35  				}
    36  				out, err := cmd.CombinedOutput()
    37  				if err != nil {
    38  					if testenv.SyscallIsNotSupported(err) {
    39  						t.Skipf("skipping: could not start process with CLONE_NEWNS and CLONE_NEWUSER: %v", err)
    40  					}
    41  					t.Errorf("%v\n%s", err, out)
    42  				}
    43  				return
    44  			}
    45  
    46  			// This test is executed in a separate user and mount namespace, thus
    47  			// we can mount a separate "/etc" empty bind mount, without the need for root access.
    48  			// On linux all certs reside in /etc, so as we bind an empty dir, we
    49  			// get a full control over the system CAs, required for this test.
    50  			if err := syscall.Mount(t.TempDir(), "/etc", "", syscall.MS_BIND, ""); err != nil {
    51  				if testenv.SyscallIsNotSupported(err) {
    52  					t.Skipf("Failed to mount /etc: %v", err)
    53  				}
    54  				t.Fatalf("Failed to mount /etc: %v", err)
    55  			}
    56  
    57  			t.Cleanup(func() {
    58  				if err := syscall.Unmount("/etc", 0); err != nil {
    59  					t.Errorf("failed to unmount /etc: %v", err)
    60  				}
    61  			})
    62  
    63  			f(t)
    64  		})
    65  	}
    66  
    67  	newFallbackCertPool := func(t *testing.T) *CertPool {
    68  		t.Helper()
    69  
    70  		const fallbackCert = `-----BEGIN CERTIFICATE-----
    71  MIICGzCCAaGgAwIBAgIQQdKd0XLq7qeAwSxs6S+HUjAKBggqhkjOPQQDAzBPMQsw
    72  CQYDVQQGEwJVUzEpMCcGA1UEChMgSW50ZXJuZXQgU2VjdXJpdHkgUmVzZWFyY2gg
    73  R3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBYMjAeFw0yMDA5MDQwMDAwMDBaFw00
    74  MDA5MTcxNjAwMDBaME8xCzAJBgNVBAYTAlVTMSkwJwYDVQQKEyBJbnRlcm5ldCBT
    75  ZWN1cml0eSBSZXNlYXJjaCBHcm91cDEVMBMGA1UEAxMMSVNSRyBSb290IFgyMHYw
    76  EAYHKoZIzj0CAQYFK4EEACIDYgAEzZvVn4CDCuwJSvMWSj5cz3es3mcFDR0HttwW
    77  +1qLFNvicWDEukWVEYmO6gbf9yoWHKS5xcUy4APgHoIYOIvXRdgKam7mAHf7AlF9
    78  ItgKbppbd9/w+kHsOdx1ymgHDB/qo0IwQDAOBgNVHQ8BAf8EBAMCAQYwDwYDVR0T
    79  AQH/BAUwAwEB/zAdBgNVHQ4EFgQUfEKWrt5LSDv6kviejM9ti6lyN5UwCgYIKoZI
    80  zj0EAwMDaAAwZQIwe3lORlCEwkSHRhtFcP9Ymd70/aTSVaYgLXTWNLxBo1BfASdW
    81  tL4ndQavEi51mI38AjEAi/V3bNTIZargCyzuFJ0nN6T5U6VR5CmD1/iQMVtCnwr1
    82  /q4AaOeMSQ+2b1tbFfLn
    83  -----END CERTIFICATE-----
    84  `
    85  		b, _ := pem.Decode([]byte(fallbackCert))
    86  		cert, err := ParseCertificate(b.Bytes)
    87  		if err != nil {
    88  			t.Fatal(err)
    89  		}
    90  		p := NewCertPool()
    91  		p.AddCert(cert)
    92  		return p
    93  	}
    94  
    95  	installSystemRootCAs := func(t *testing.T) {
    96  		t.Helper()
    97  
    98  		const systemCAs = `-----BEGIN CERTIFICATE-----
    99  MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw
   100  TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh
   101  cmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMTUwNjA0MTEwNDM4
   102  WhcNMzUwNjA0MTEwNDM4WjBPMQswCQYDVQQGEwJVUzEpMCcGA1UEChMgSW50ZXJu
   103  ZXQgU2VjdXJpdHkgUmVzZWFyY2ggR3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBY
   104  MTCCAiIwDQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIBAK3oJHP0FDfzm54rVygc
   105  h77ct984kIxuPOZXoHj3dcKi/vVqbvYATyjb3miGbESTtrFj/RQSa78f0uoxmyF+
   106  0TM8ukj13Xnfs7j/EvEhmkvBioZxaUpmZmyPfjxwv60pIgbz5MDmgK7iS4+3mX6U
   107  A5/TR5d8mUgjU+g4rk8Kb4Mu0UlXjIB0ttov0DiNewNwIRt18jA8+o+u3dpjq+sW
   108  T8KOEUt+zwvo/7V3LvSye0rgTBIlDHCNAymg4VMk7BPZ7hm/ELNKjD+Jo2FR3qyH
   109  B5T0Y3HsLuJvW5iB4YlcNHlsdu87kGJ55tukmi8mxdAQ4Q7e2RCOFvu396j3x+UC
   110  B5iPNgiV5+I3lg02dZ77DnKxHZu8A/lJBdiB3QW0KtZB6awBdpUKD9jf1b0SHzUv
   111  KBds0pjBqAlkd25HN7rOrFleaJ1/ctaJxQZBKT5ZPt0m9STJEadao0xAH0ahmbWn
   112  OlFuhjuefXKnEgV4We0+UXgVCwOPjdAvBbI+e0ocS3MFEvzG6uBQE3xDk3SzynTn
   113  jh8BCNAw1FtxNrQHusEwMFxIt4I7mKZ9YIqioymCzLq9gwQbooMDQaHWBfEbwrbw
   114  qHyGO0aoSCqI3Haadr8faqU9GY/rOPNk3sgrDQoo//fb4hVC1CLQJ13hef4Y53CI
   115  rU7m2Ys6xt0nUW7/vGT1M0NPAgMBAAGjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNV
   116  HRMBAf8EBTADAQH/MB0GA1UdDgQWBBR5tFnme7bl5AFzgAiIyBpY9umbbjANBgkq
   117  hkiG9w0BAQsFAAOCAgEAVR9YqbyyqFDQDLHYGmkgJykIrGF1XIpu+ILlaS/V9lZL
   118  ubhzEFnTIZd+50xx+7LSYK05qAvqFyFWhfFQDlnrzuBZ6brJFe+GnY+EgPbk6ZGQ
   119  3BebYhtF8GaV0nxvwuo77x/Py9auJ/GpsMiu/X1+mvoiBOv/2X/qkSsisRcOj/KK
   120  NFtY2PwByVS5uCbMiogziUwthDyC3+6WVwW6LLv3xLfHTjuCvjHIInNzktHCgKQ5
   121  ORAzI4JMPJ+GslWYHb4phowim57iaztXOoJwTdwJx4nLCgdNbOhdjsnvzqvHu7Ur
   122  TkXWStAmzOVyyghqpZXjFaH3pO3JLF+l+/+sKAIuvtd7u+Nxe5AW0wdeRlN8NwdC
   123  jNPElpzVmbUq4JUagEiuTDkHzsxHpFKVK7q4+63SM1N95R1NbdWhscdCb+ZAJzVc
   124  oyi3B43njTOQ5yOf+1CceWxG1bQVs5ZufpsMljq4Ui0/1lvh+wjChP4kqKOJ2qxq
   125  4RgqsahDYVvTH9w7jXbyLeiNdd8XM2w9U/t7y0Ff/9yi0GE44Za4rF2LN9d11TPA
   126  mRGunUHBcnWEvgJBQl9nJEiU0Zsnvgc/ubhPgXRR4Xq37Z0j4r7g1SgEEzwxA57d
   127  emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc=
   128  -----END CERTIFICATE-----
   129  `
   130  		if err := os.MkdirAll("/etc/ssl/certs", 06660); err != nil {
   131  			t.Fatal(err)
   132  		}
   133  
   134  		if err := os.WriteFile("/etc/ssl/certs/ca-certificates.crt", []byte(systemCAs), 0666); err != nil {
   135  			t.Fatal(err)
   136  		}
   137  	}
   138  
   139  	test(t, "after_first_load_no_system_CAs", func(t *testing.T) {
   140  		SystemCertPool() // load system certs, before setting fallbacks
   141  		fallback := newFallbackCertPool(t)
   142  		SetFallbackRoots(fallback)
   143  		got, err := SystemCertPool()
   144  		if err != nil {
   145  			t.Fatal(err)
   146  		}
   147  		if !got.Equal(fallback) {
   148  			t.Fatal("SystemCertPool returned a non-fallback CertPool")
   149  		}
   150  	})
   151  
   152  	test(t, "after_first_load_system_CA_read_error", func(t *testing.T) {
   153  		// This will fail to load in SystemCertPool since this is a directory,
   154  		// rather than a file with certificates.
   155  		if err := os.MkdirAll("/etc/ssl/certs/ca-certificates.crt", 0666); err != nil {
   156  			t.Fatal(err)
   157  		}
   158  
   159  		_, err := SystemCertPool() // load system certs, before setting fallbacks
   160  		if err == nil {
   161  			t.Fatal("unexpected success")
   162  		}
   163  
   164  		fallback := newFallbackCertPool(t)
   165  		SetFallbackRoots(fallback)
   166  		got, err := SystemCertPool()
   167  		if err != nil {
   168  			t.Fatal(err)
   169  		}
   170  		if !got.Equal(fallback) {
   171  			t.Fatal("SystemCertPool returned a non-fallback CertPool")
   172  		}
   173  	})
   174  
   175  	test(t, "after_first_load_with_system_CAs", func(t *testing.T) {
   176  		installSystemRootCAs(t)
   177  
   178  		SystemCertPool() // load system certs, before setting fallbacks
   179  
   180  		fallback := newFallbackCertPool(t)
   181  		SetFallbackRoots(fallback)
   182  		got, err := SystemCertPool()
   183  		if err != nil {
   184  			t.Fatal(err)
   185  		}
   186  		if got.Equal(fallback) {
   187  			t.Fatal("SystemCertPool returned the fallback CertPool")
   188  		}
   189  	})
   190  
   191  	test(t, "before_first_load_no_system_CAs", func(t *testing.T) {
   192  		fallback := newFallbackCertPool(t)
   193  		SetFallbackRoots(fallback)
   194  		got, err := SystemCertPool()
   195  		if err != nil {
   196  			t.Fatal(err)
   197  		}
   198  		if !got.Equal(fallback) {
   199  			t.Fatal("SystemCertPool returned a non-fallback CertPool")
   200  		}
   201  	})
   202  
   203  	test(t, "before_first_load_system_CA_read_error", func(t *testing.T) {
   204  		// This will fail to load in SystemCertPool since this is a directory,
   205  		// rather than a file with certificates.
   206  		if err := os.MkdirAll("/etc/ssl/certs/ca-certificates.crt", 0666); err != nil {
   207  			t.Fatal(err)
   208  		}
   209  
   210  		fallback := newFallbackCertPool(t)
   211  		SetFallbackRoots(fallback)
   212  		got, err := SystemCertPool()
   213  		if err != nil {
   214  			t.Fatal(err)
   215  		}
   216  		if !got.Equal(fallback) {
   217  			t.Fatal("SystemCertPool returned a non-fallback CertPool")
   218  		}
   219  	})
   220  
   221  	test(t, "before_first_load_with_system_CAs", func(t *testing.T) {
   222  		installSystemRootCAs(t)
   223  
   224  		fallback := newFallbackCertPool(t)
   225  		SetFallbackRoots(fallback)
   226  		got, err := SystemCertPool()
   227  		if err != nil {
   228  			t.Fatal(err)
   229  		}
   230  		if got.Equal(fallback) {
   231  			t.Fatal("SystemCertPool returned the fallback CertPool")
   232  		}
   233  	})
   234  
   235  	test(t, "before_first_load_force_godebug", func(t *testing.T) {
   236  		if err := os.Setenv("GODEBUG", "x509usefallbackroots=1"); err != nil {
   237  			t.Fatal(err)
   238  		}
   239  
   240  		installSystemRootCAs(t)
   241  
   242  		fallback := newFallbackCertPool(t)
   243  		SetFallbackRoots(fallback)
   244  		got, err := SystemCertPool()
   245  		if err != nil {
   246  			t.Fatal(err)
   247  		}
   248  		if !got.Equal(fallback) {
   249  			t.Fatal("SystemCertPool returned a non-fallback CertPool")
   250  		}
   251  	})
   252  
   253  	test(t, "after_first_load_force_godebug", func(t *testing.T) {
   254  		if err := os.Setenv("GODEBUG", "x509usefallbackroots=1"); err != nil {
   255  			t.Fatal(err)
   256  		}
   257  
   258  		installSystemRootCAs(t)
   259  		SystemCertPool() // load system certs, before setting fallbacks
   260  
   261  		fallback := newFallbackCertPool(t)
   262  		SetFallbackRoots(fallback)
   263  		got, err := SystemCertPool()
   264  		if err != nil {
   265  			t.Fatal(err)
   266  		}
   267  		if !got.Equal(fallback) {
   268  			t.Fatal("SystemCertPool returned a non-fallback CertPool")
   269  		}
   270  	})
   271  
   272  	test(t, "after_first_load_force_godebug_no_system_certs", func(t *testing.T) {
   273  		if err := os.Setenv("GODEBUG", "x509usefallbackroots=1"); err != nil {
   274  			t.Fatal(err)
   275  		}
   276  
   277  		SystemCertPool() // load system certs, before setting fallbacks
   278  
   279  		fallback := newFallbackCertPool(t)
   280  		SetFallbackRoots(fallback)
   281  		got, err := SystemCertPool()
   282  		if err != nil {
   283  			t.Fatal(err)
   284  		}
   285  		if !got.Equal(fallback) {
   286  			t.Fatal("SystemCertPool returned a non-fallback CertPool")
   287  		}
   288  	})
   289  }
   290
View as plain text