github.com/xushiwei/go@v0.0.0-20130601165731-2b9d83f45bc9/src/pkg/crypto/x509/cert_pool.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  package x509
     6  
     7  import (
     8  	"encoding/pem"
     9  )
    10  
    11  // CertPool is a set of certificates.
    12  type CertPool struct {
    13  	bySubjectKeyId map[string][]int
    14  	byName         map[string][]int
    15  	certs          []*Certificate
    16  }
    17  
    18  // NewCertPool returns a new, empty CertPool.
    19  func NewCertPool() *CertPool {
    20  	return &CertPool{
    21  		make(map[string][]int),
    22  		make(map[string][]int),
    23  		nil,
    24  	}
    25  }
    26  
    27  // findVerifiedParents attempts to find certificates in s which have signed the
    28  // given certificate. If no such certificate can be found or the signature
    29  // doesn't match, it returns nil.
    30  func (s *CertPool) findVerifiedParents(cert *Certificate) (parents []int) {
    31  	if s == nil {
    32  		return
    33  	}
    34  	var candidates []int
    35  
    36  	if len(cert.AuthorityKeyId) > 0 {
    37  		candidates = s.bySubjectKeyId[string(cert.AuthorityKeyId)]
    38  	}
    39  	if len(candidates) == 0 {
    40  		candidates = s.byName[string(cert.RawIssuer)]
    41  	}
    42  
    43  	for _, c := range candidates {
    44  		if cert.CheckSignatureFrom(s.certs[c]) == nil {
    45  			parents = append(parents, c)
    46  		}
    47  	}
    48  
    49  	return
    50  }
    51  
    52  // AddCert adds a certificate to a pool.
    53  func (s *CertPool) AddCert(cert *Certificate) {
    54  	if cert == nil {
    55  		panic("adding nil Certificate to CertPool")
    56  	}
    57  
    58  	// Check that the certificate isn't being added twice.
    59  	for _, c := range s.certs {
    60  		if c.Equal(cert) {
    61  			return
    62  		}
    63  	}
    64  
    65  	n := len(s.certs)
    66  	s.certs = append(s.certs, cert)
    67  
    68  	if len(cert.SubjectKeyId) > 0 {
    69  		keyId := string(cert.SubjectKeyId)
    70  		s.bySubjectKeyId[keyId] = append(s.bySubjectKeyId[keyId], n)
    71  	}
    72  	name := string(cert.RawSubject)
    73  	s.byName[name] = append(s.byName[name], n)
    74  }
    75  
    76  // AppendCertsFromPEM attempts to parse a series of PEM encoded certificates.
    77  // It appends any certificates found to s and returns true if any certificates
    78  // were successfully parsed.
    79  //
    80  // On many Linux systems, /etc/ssl/cert.pem will contain the system wide set
    81  // of root CAs in a format suitable for this function.
    82  func (s *CertPool) AppendCertsFromPEM(pemCerts []byte) (ok bool) {
    83  	for len(pemCerts) > 0 {
    84  		var block *pem.Block
    85  		block, pemCerts = pem.Decode(pemCerts)
    86  		if block == nil {
    87  			break
    88  		}
    89  		if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
    90  			continue
    91  		}
    92  
    93  		cert, err := ParseCertificate(block.Bytes)
    94  		if err != nil {
    95  			continue
    96  		}
    97  
    98  		s.AddCert(cert)
    99  		ok = true
   100  	}
   101  
   102  	return
   103  }
   104  
   105  // Subjects returns a list of the DER-encoded subjects of
   106  // all of the certificates in the pool.
   107  func (s *CertPool) Subjects() (res [][]byte) {
   108  	res = make([][]byte, len(s.certs))
   109  	for i, c := range s.certs {
   110  		res[i] = c.RawSubject
   111  	}
   112  	return
   113  }