src/crypto/x509/root_darwin.go - go - Git at Google

 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 //go:generate go run root_darwin_arm_gen.go -output root_darwin_armx.go

 package x509

 import (
 	"bufio"
 	"bytes"
 	"crypto/sha1"
 	"encoding/pem"
 	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
 	"sync"
 )

 var debugDarwinRoots = strings.Contains(os.Getenv("GODEBUG"), "x509roots=1")

 func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
 	return nil, nil
 }

 // This code is only used when compiling without cgo.
 // It is here, instead of root_nocgo_darwin.go, so that tests can check it
 // even if the tests are run with cgo enabled.
 // The linker will not include these unused functions in binaries built with cgo enabled.

 // execSecurityRoots finds the macOS list of trusted root certificates
 // using only command-line tools. This is our fallback path when cgo isn't available.
 //
 // The strategy is as follows:
 //
 // 1. Run "security trust-settings-export" and "security
 //    trust-settings-export -d" to discover the set of certs with some
 //    user-tweaked trust policy. We're too lazy to parse the XML
 //    (Issue 26830) to understand what the trust
 //    policy actually is. We just learn that there is _some_ policy.
 //
 // 2. Run "security find-certificate" to dump the list of system root
 //    CAs in PEM format.
 //
 // 3. For each dumped cert, conditionally verify it with "security
 //    verify-cert" if that cert was in the set discovered in Step 1.
 //    Without the Step 1 optimization, running "security verify-cert"
 //    150-200 times takes 3.5 seconds. With the optimization, the
 //    whole process takes about 180 milliseconds with 1 untrusted root
 //    CA. (Compared to 110ms in the cgo path)
 func execSecurityRoots() (*CertPool, error) {
 	hasPolicy, err := getCertsWithTrustPolicy()
 	if err != nil {
 		return nil, err
 	}
 	if debugDarwinRoots {
 		fmt.Printf("crypto/x509: %d certs have a trust policy\n", len(hasPolicy))
 	}

 	keychains := []string{"/Library/Keychains/System.keychain"}

 	// Note that this results in trusting roots from $HOME/... (the environment
 	// variable), which might not be expected.
 	home, err := os.UserHomeDir()
 	if err != nil {
 		if debugDarwinRoots {
 			fmt.Printf("crypto/x509: can't get user home directory: %v\n", err)
 		}
 	} else {
 		keychains = append(keychains,
 			filepath.Join(home, "/Library/Keychains/login.keychain"),

 			// Fresh installs of Sierra use a slightly different path for the login keychain
 			filepath.Join(home, "/Library/Keychains/login.keychain-db"),
 		)
 	}

 	type rootCandidate struct {
 		c      *Certificate
 		system bool
 	}

 	var (
 		mu          sync.Mutex
 		roots       = NewCertPool()
 		numVerified int // number of execs of 'security verify-cert', for debug stats
 		wg          sync.WaitGroup
 		verifyCh    = make(chan rootCandidate)
 	)

 	// Using 4 goroutines to pipe into verify-cert seems to be
 	// about the best we can do. The verify-cert binary seems to
 	// just RPC to another server with coarse locking anyway, so
 	// running 16 at a time for instance doesn't help at all. Due
 	// to the "if hasPolicy" check below, though, we will rarely
 	// (or never) call verify-cert on stock macOS systems, though.
 	// The hope is that we only call verify-cert when the user has
 	// tweaked their trust policy. These 4 goroutines are only
 	// defensive in the pathological case of many trust edits.
 	for i := 0; i < 4; i++ {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
 			for cert := range verifyCh {
 				sha1CapHex := fmt.Sprintf("%X", sha1.Sum(cert.c.Raw))

 				var valid bool
 				verifyChecks := 0
 				if hasPolicy[sha1CapHex] {
 					verifyChecks++
 					valid = verifyCertWithSystem(cert.c)
 				} else {
 					// Certificates not in SystemRootCertificates without user
 					// or admin trust settings are not trusted.
 					valid = cert.system
 				}

 				mu.Lock()
 				numVerified += verifyChecks
 				if valid {
 					roots.AddCert(cert.c)
 				}
 				mu.Unlock()
 			}
 		}()
 	}
 	err = forEachCertInKeychains(keychains, func(cert *Certificate) {
 		verifyCh <- rootCandidate{c: cert, system: false}
 	})
 	if err != nil {
 		close(verifyCh)
 		return nil, err
 	}
 	err = forEachCertInKeychains([]string{
 		"/System/Library/Keychains/SystemRootCertificates.keychain",
 	}, func(cert *Certificate) {
 		verifyCh <- rootCandidate{c: cert, system: true}
 	})
 	if err != nil {
 		close(verifyCh)
 		return nil, err
 	}
 	close(verifyCh)
 	wg.Wait()

 	if debugDarwinRoots {
 		fmt.Printf("crypto/x509: ran security verify-cert %d times\n", numVerified)
 	}

 	return roots, nil
 }

 func forEachCertInKeychains(paths []string, f func(*Certificate)) error {
 	args := append([]string{"find-certificate", "-a", "-p"}, paths...)
 	cmd := exec.Command("/usr/bin/security", args...)
 	data, err := cmd.Output()
 	if err != nil {
 		return err
 	}
 	for len(data) > 0 {
 		var block *pem.Block
 		block, data = pem.Decode(data)
 		if block == nil {
 			break
 		}
 		if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
 			continue
 		}
 		cert, err := ParseCertificate(block.Bytes)
 		if err != nil {
 			continue
 		}
 		f(cert)
 	}
 	return nil
 }

 func verifyCertWithSystem(cert *Certificate) bool {
 	data := pem.EncodeToMemory(&pem.Block{
 		Type: "CERTIFICATE", Bytes: cert.Raw,
 	})

 	f, err := ioutil.TempFile("", "cert")
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "can't create temporary file for cert: %v", err)
 		return false
 	}
 	defer os.Remove(f.Name())
 	if _, err := f.Write(data); err != nil {
 		fmt.Fprintf(os.Stderr, "can't write temporary file for cert: %v", err)
 		return false
 	}
 	if err := f.Close(); err != nil {
 		fmt.Fprintf(os.Stderr, "can't write temporary file for cert: %v", err)
 		return false
 	}
 	cmd := exec.Command("/usr/bin/security", "verify-cert", "-p", "ssl", "-c", f.Name(), "-l", "-L")
 	var stderr bytes.Buffer
 	if debugDarwinRoots {
 		cmd.Stderr = &stderr
 	}
 	if err := cmd.Run(); err != nil {
 		if debugDarwinRoots {
 			fmt.Printf("crypto/x509: verify-cert rejected %s: %q\n", cert.Subject, bytes.TrimSpace(stderr.Bytes()))
 		}
 		return false
 	}
 	if debugDarwinRoots {
 		fmt.Printf("crypto/x509: verify-cert approved %s\n", cert.Subject)
 	}
 	return true
 }

 // getCertsWithTrustPolicy returns the set of certs that have a
 // possibly-altered trust policy. The keys of the map are capitalized
 // sha1 hex of the raw cert.
 // They are the certs that should be checked against `security
 // verify-cert` to see whether the user altered the default trust
 // settings. This code is only used for cgo-disabled builds.
 func getCertsWithTrustPolicy() (map[string]bool, error) {
 	set := map[string]bool{}
 	td, err := ioutil.TempDir("", "x509trustpolicy")
 	if err != nil {
 		return nil, err
 	}
 	defer os.RemoveAll(td)
 	run := func(file string, args ...string) error {
 		file = filepath.Join(td, file)
 		args = append(args, file)
 		cmd := exec.Command("/usr/bin/security", args...)
 		var stderr bytes.Buffer
 		cmd.Stderr = &stderr
 		if err := cmd.Run(); err != nil {
 			// If there are no trust settings, the
 			// `security trust-settings-export` command
 			// fails with:
 			//    exit status 1, SecTrustSettingsCreateExternalRepresentation: No Trust Settings were found.
 			// Rather than match on English substrings that are probably
 			// localized on macOS, just interpret any failure to mean that
 			// there are no trust settings.
 			if debugDarwinRoots {
 				fmt.Printf("crypto/x509: exec %q: %v, %s\n", cmd.Args, err, stderr.Bytes())
 			}
 			return nil
 		}

 		f, err := os.Open(file)
 		if err != nil {
 			return err
 		}
 		defer f.Close()

 		// Gather all the runs of 40 capitalized hex characters.
 		br := bufio.NewReader(f)
 		var hexBuf bytes.Buffer
 		for {
 			b, err := br.ReadByte()
 			isHex := ('A' <= b && b <= 'F') || ('0' <= b && b <= '9')
 			if isHex {
 				hexBuf.WriteByte(b)
 			} else {
 				if hexBuf.Len() == 40 {
 					set[hexBuf.String()] = true
 				}
 				hexBuf.Reset()
 			}
 			if err == io.EOF {
 				break
 			}
 			if err != nil {
 				return err
 			}
 		}

 		return nil
 	}
 	if err := run("user", "trust-settings-export"); err != nil {
 		return nil, fmt.Errorf("dump-trust-settings (user): %v", err)
 	}
 	if err := run("admin", "trust-settings-export", "-d"); err != nil {
 		return nil, fmt.Errorf("dump-trust-settings (admin): %v", err)
 	}
 	return set, nil
 }
	// Copyright 2013 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	//go:generate go run root_darwin_arm_gen.go -output root_darwin_armx.go

	package x509

	import (
	"bufio"
	"bytes"
	"crypto/sha1"
	"encoding/pem"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"sync"
	)

	var debugDarwinRoots = strings.Contains(os.Getenv("GODEBUG"), "x509roots=1")

	func (c Certificate) systemVerify(opts VerifyOptions) (chains [][]*Certificate, err error) {
	return nil, nil
	}

	// This code is only used when compiling without cgo.
	// It is here, instead of root_nocgo_darwin.go, so that tests can check it
	// even if the tests are run with cgo enabled.
	// The linker will not include these unused functions in binaries built with cgo enabled.

	// execSecurityRoots finds the macOS list of trusted root certificates
	// using only command-line tools. This is our fallback path when cgo isn't available.
	//
	// The strategy is as follows:
	//
	// 1. Run "security trust-settings-export" and "security
	// trust-settings-export -d" to discover the set of certs with some
	// user-tweaked trust policy. We're too lazy to parse the XML
	// (Issue 26830) to understand what the trust
	// policy actually is. We just learn that there is _some_ policy.
	//
	// 2. Run "security find-certificate" to dump the list of system root
	// CAs in PEM format.
	//
	// 3. For each dumped cert, conditionally verify it with "security
	// verify-cert" if that cert was in the set discovered in Step 1.
	// Without the Step 1 optimization, running "security verify-cert"
	// 150-200 times takes 3.5 seconds. With the optimization, the
	// whole process takes about 180 milliseconds with 1 untrusted root
	// CA. (Compared to 110ms in the cgo path)
	func execSecurityRoots() (*CertPool, error) {
	hasPolicy, err := getCertsWithTrustPolicy()
	if err != nil {
	return nil, err
	}
	if debugDarwinRoots {
	fmt.Printf("crypto/x509: %d certs have a trust policy\n", len(hasPolicy))
	}

	keychains := []string{"/Library/Keychains/System.keychain"}

	// Note that this results in trusting roots from $HOME/... (the environment
	// variable), which might not be expected.
	home, err := os.UserHomeDir()
	if err != nil {
	if debugDarwinRoots {
	fmt.Printf("crypto/x509: can't get user home directory: %v\n", err)
	}
	} else {
	keychains = append(keychains,
	filepath.Join(home, "/Library/Keychains/login.keychain"),

	// Fresh installs of Sierra use a slightly different path for the login keychain
	filepath.Join(home, "/Library/Keychains/login.keychain-db"),
	)
	}

	type rootCandidate struct {
	c *Certificate
	system bool
	}

	var (
	mu sync.Mutex
	roots = NewCertPool()
	numVerified int // number of execs of 'security verify-cert', for debug stats
	wg sync.WaitGroup
	verifyCh = make(chan rootCandidate)
	)

	// Using 4 goroutines to pipe into verify-cert seems to be
	// about the best we can do. The verify-cert binary seems to
	// just RPC to another server with coarse locking anyway, so
	// running 16 at a time for instance doesn't help at all. Due
	// to the "if hasPolicy" check below, though, we will rarely
	// (or never) call verify-cert on stock macOS systems, though.
	// The hope is that we only call verify-cert when the user has
	// tweaked their trust policy. These 4 goroutines are only
	// defensive in the pathological case of many trust edits.
	for i := 0; i < 4; i++ {
	wg.Add(1)
	go func() {
	defer wg.Done()
	for cert := range verifyCh {
	sha1CapHex := fmt.Sprintf("%X", sha1.Sum(cert.c.Raw))

	var valid bool
	verifyChecks := 0
	if hasPolicy[sha1CapHex] {
	verifyChecks++
	valid = verifyCertWithSystem(cert.c)
	} else {
	// Certificates not in SystemRootCertificates without user
	// or admin trust settings are not trusted.
	valid = cert.system
	}

	mu.Lock()
	numVerified += verifyChecks
	if valid {
	roots.AddCert(cert.c)
	}
	mu.Unlock()
	}
	}()
	}
	err = forEachCertInKeychains(keychains, func(cert *Certificate) {
	verifyCh <- rootCandidate{c: cert, system: false}
	})
	if err != nil {
	close(verifyCh)
	return nil, err
	}
	err = forEachCertInKeychains([]string{
	"/System/Library/Keychains/SystemRootCertificates.keychain",
	}, func(cert *Certificate) {
	verifyCh <- rootCandidate{c: cert, system: true}
	})
	if err != nil {
	close(verifyCh)
	return nil, err
	}
	close(verifyCh)
	wg.Wait()

	if debugDarwinRoots {
	fmt.Printf("crypto/x509: ran security verify-cert %d times\n", numVerified)
	}

	return roots, nil
	}

	func forEachCertInKeychains(paths []string, f func(*Certificate)) error {
	args := append([]string{"find-certificate", "-a", "-p"}, paths...)
	cmd := exec.Command("/usr/bin/security", args...)
	data, err := cmd.Output()
	if err != nil {
	return err
	}
	for len(data) > 0 {
	var block *pem.Block
	block, data = pem.Decode(data)
	if block == nil {
	break
	}
	if block.Type != "CERTIFICATE" \|\| len(block.Headers) != 0 {
	continue
	}
	cert, err := ParseCertificate(block.Bytes)
	if err != nil {
	continue
	}
	f(cert)
	}
	return nil
	}

	func verifyCertWithSystem(cert *Certificate) bool {
	data := pem.EncodeToMemory(&pem.Block{
	Type: "CERTIFICATE", Bytes: cert.Raw,
	})

	f, err := ioutil.TempFile("", "cert")
	if err != nil {
	fmt.Fprintf(os.Stderr, "can't create temporary file for cert: %v", err)
	return false
	}
	defer os.Remove(f.Name())
	if _, err := f.Write(data); err != nil {
	fmt.Fprintf(os.Stderr, "can't write temporary file for cert: %v", err)
	return false
	}
	if err := f.Close(); err != nil {
	fmt.Fprintf(os.Stderr, "can't write temporary file for cert: %v", err)
	return false
	}
	cmd := exec.Command("/usr/bin/security", "verify-cert", "-p", "ssl", "-c", f.Name(), "-l", "-L")
	var stderr bytes.Buffer
	if debugDarwinRoots {
	cmd.Stderr = &stderr
	}
	if err := cmd.Run(); err != nil {
	if debugDarwinRoots {
	fmt.Printf("crypto/x509: verify-cert rejected %s: %q\n", cert.Subject, bytes.TrimSpace(stderr.Bytes()))
	}
	return false
	}
	if debugDarwinRoots {
	fmt.Printf("crypto/x509: verify-cert approved %s\n", cert.Subject)
	}
	return true
	}

	// getCertsWithTrustPolicy returns the set of certs that have a
	// possibly-altered trust policy. The keys of the map are capitalized
	// sha1 hex of the raw cert.
	// They are the certs that should be checked against `security
	// verify-cert` to see whether the user altered the default trust
	// settings. This code is only used for cgo-disabled builds.
	func getCertsWithTrustPolicy() (map[string]bool, error) {
	set := map[string]bool{}
	td, err := ioutil.TempDir("", "x509trustpolicy")
	if err != nil {
	return nil, err
	}
	defer os.RemoveAll(td)
	run := func(file string, args ...string) error {
	file = filepath.Join(td, file)
	args = append(args, file)
	cmd := exec.Command("/usr/bin/security", args...)
	var stderr bytes.Buffer
	cmd.Stderr = &stderr
	if err := cmd.Run(); err != nil {
	// If there are no trust settings, the
	// `security trust-settings-export` command
	// fails with:
	// exit status 1, SecTrustSettingsCreateExternalRepresentation: No Trust Settings were found.
	// Rather than match on English substrings that are probably
	// localized on macOS, just interpret any failure to mean that
	// there are no trust settings.
	if debugDarwinRoots {
	fmt.Printf("crypto/x509: exec %q: %v, %s\n", cmd.Args, err, stderr.Bytes())
	}
	return nil
	}

	f, err := os.Open(file)
	if err != nil {
	return err
	}
	defer f.Close()

	// Gather all the runs of 40 capitalized hex characters.
	br := bufio.NewReader(f)
	var hexBuf bytes.Buffer
	for {
	b, err := br.ReadByte()
	isHex := ('A' <= b && b <= 'F') \|\| ('0' <= b && b <= '9')
	if isHex {
	hexBuf.WriteByte(b)
	} else {
	if hexBuf.Len() == 40 {
	set[hexBuf.String()] = true
	}
	hexBuf.Reset()
	}
	if err == io.EOF {
	break
	}
	if err != nil {
	return err
	}
	}

	return nil
	}
	if err := run("user", "trust-settings-export"); err != nil {
	return nil, fmt.Errorf("dump-trust-settings (user): %v", err)
	}
	if err := run("admin", "trust-settings-export", "-d"); err != nil {
	return nil, fmt.Errorf("dump-trust-settings (admin): %v", err)
	}
	return set, nil
	}