github.com/code-reading/golang@v0.0.0-20220303082512-ba5bc0e589a3/go/src/crypto/x509/root_unix.go (about)

     1  // Copyright 2011 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 aix || dragonfly || freebsd || (js && wasm) || linux || netbsd || openbsd || solaris
     6  // +build aix dragonfly freebsd js,wasm linux netbsd openbsd solaris
     7  
     8  package x509
     9  
    10  import (
    11  	"io/fs"
    12  	"os"
    13  	"path/filepath"
    14  	"strings"
    15  )
    16  
    17  const (
    18  	// certFileEnv is the environment variable which identifies where to locate
    19  	// the SSL certificate file. If set this overrides the system default.
    20  	certFileEnv = "SSL_CERT_FILE"
    21  
    22  	// certDirEnv is the environment variable which identifies which directory
    23  	// to check for SSL certificate files. If set this overrides the system default.
    24  	// It is a colon separated list of directories.
    25  	// See https://www.openssl.org/docs/man1.0.2/man1/c_rehash.html.
    26  	certDirEnv = "SSL_CERT_DIR"
    27  )
    28  
    29  func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
    30  	return nil, nil
    31  }
    32  
    33  func loadSystemRoots() (*CertPool, error) {
    34  	roots := NewCertPool()
    35  
    36  	files := certFiles
    37  	if f := os.Getenv(certFileEnv); f != "" {
    38  		files = []string{f}
    39  	}
    40  
    41  	var firstErr error
    42  	for _, file := range files {
    43  		data, err := os.ReadFile(file)
    44  		if err == nil {
    45  			roots.AppendCertsFromPEM(data)
    46  			break
    47  		}
    48  		if firstErr == nil && !os.IsNotExist(err) {
    49  			firstErr = err
    50  		}
    51  	}
    52  
    53  	dirs := certDirectories
    54  	if d := os.Getenv(certDirEnv); d != "" {
    55  		// OpenSSL and BoringSSL both use ":" as the SSL_CERT_DIR separator.
    56  		// See:
    57  		//  * https://golang.org/issue/35325
    58  		//  * https://www.openssl.org/docs/man1.0.2/man1/c_rehash.html
    59  		dirs = strings.Split(d, ":")
    60  	}
    61  
    62  	for _, directory := range dirs {
    63  		fis, err := readUniqueDirectoryEntries(directory)
    64  		if err != nil {
    65  			if firstErr == nil && !os.IsNotExist(err) {
    66  				firstErr = err
    67  			}
    68  			continue
    69  		}
    70  		for _, fi := range fis {
    71  			data, err := os.ReadFile(directory + "/" + fi.Name())
    72  			if err == nil {
    73  				roots.AppendCertsFromPEM(data)
    74  			}
    75  		}
    76  	}
    77  
    78  	if roots.len() > 0 || firstErr == nil {
    79  		return roots, nil
    80  	}
    81  
    82  	return nil, firstErr
    83  }
    84  
    85  // readUniqueDirectoryEntries is like os.ReadDir but omits
    86  // symlinks that point within the directory.
    87  func readUniqueDirectoryEntries(dir string) ([]fs.DirEntry, error) {
    88  	files, err := os.ReadDir(dir)
    89  	if err != nil {
    90  		return nil, err
    91  	}
    92  	uniq := files[:0]
    93  	for _, f := range files {
    94  		if !isSameDirSymlink(f, dir) {
    95  			uniq = append(uniq, f)
    96  		}
    97  	}
    98  	return uniq, nil
    99  }
   100  
   101  // isSameDirSymlink reports whether fi in dir is a symlink with a
   102  // target not containing a slash.
   103  func isSameDirSymlink(f fs.DirEntry, dir string) bool {
   104  	if f.Type()&fs.ModeSymlink == 0 {
   105  		return false
   106  	}
   107  	target, err := os.Readlink(filepath.Join(dir, f.Name()))
   108  	return err == nil && !strings.Contains(target, "/")
   109  }