vendor/golang.org/x/crypto/openpgp/packet/one_pass_signature.go

   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 packet
   6
   7 import (
   8         "crypto"
   9         "encoding/binary"
  10         "golang.org/x/crypto/openpgp/errors"
  11         "golang.org/x/crypto/openpgp/s2k"
  12         "io"
  13         "strconv"
  14 )
  15
  16 // OnePassSignature represents a one-pass signature packet. See RFC 4880,
  17 // section 5.4.
  18 type OnePassSignature struct {
  19         SigType    SignatureType
  20         Hash       crypto.Hash
  21         PubKeyAlgo PublicKeyAlgorithm
  22         KeyId      uint64
  23         IsLast     bool
  24 }
  25
  26 const onePassSignatureVersion = 3
  27
  28 func (ops *OnePassSignature) parse(r io.Reader) (err error) {
  29         var buf [13]byte
  30
  31         _, err = readFull(r, buf[:])
  32         if err != nil {
  33                 return
  34         }
  35         if buf[0] != onePassSignatureVersion {
  36                 err = errors.UnsupportedError("one-pass-signature packet version " + strconv.Itoa(int(buf[0])))
  37         }
  38
  39         var ok bool
  40         ops.Hash, ok = s2k.HashIdToHash(buf[2])
  41         if !ok {
  42                 return errors.UnsupportedError("hash function: " + strconv.Itoa(int(buf[2])))
  43         }
  44
  45         ops.SigType = SignatureType(buf[1])
  46         ops.PubKeyAlgo = PublicKeyAlgorithm(buf[3])
  47         ops.KeyId = binary.BigEndian.Uint64(buf[4:12])
  48         ops.IsLast = buf[12] != 0
  49         return
  50 }
  51
  52 // Serialize marshals the given OnePassSignature to w.
  53 func (ops *OnePassSignature) Serialize(w io.Writer) error {
  54         var buf [13]byte
  55         buf[0] = onePassSignatureVersion
  56         buf[1] = uint8(ops.SigType)
  57         var ok bool
  58         buf[2], ok = s2k.HashToHashId(ops.Hash)
  59         if !ok {
  60                 return errors.UnsupportedError("hash type: " + strconv.Itoa(int(ops.Hash)))
  61         }
  62         buf[3] = uint8(ops.PubKeyAlgo)
  63         binary.BigEndian.PutUint64(buf[4:12], ops.KeyId)
  64         if ops.IsLast {
  65                 buf[12] = 1
  66         }
  67
  68         if err := serializeHeader(w, packetTypeOnePassSignature, len(buf)); err != nil {
  69                 return err
  70         }
  71         _, err := w.Write(buf[:])
  72         return err
  73 }