vendor/golang.org/x/crypto/openpgp/canonical_text.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 openpgp
   6
   7 import "hash"
   8
   9 // NewCanonicalTextHash reformats text written to it into the canonical
  10 // form and then applies the hash h.  See RFC 4880, section 5.2.1.
  11 func NewCanonicalTextHash(h hash.Hash) hash.Hash {
  12         return &canonicalTextHash{h, 0}
  13 }
  14
  15 type canonicalTextHash struct {
  16         h hash.Hash
  17         s int
  18 }
  19
  20 var newline = []byte{'\r', '\n'}
  21
  22 func (cth *canonicalTextHash) Write(buf []byte) (int, error) {
  23         start := 0
  24
  25         for i, c := range buf {
  26                 switch cth.s {
  27                 case 0:
  28                         if c == '\r' {
  29                                 cth.s = 1
  30                         } else if c == '\n' {
  31                                 cth.h.Write(buf[start:i])
  32                                 cth.h.Write(newline)
  33                                 start = i + 1
  34                         }
  35                 case 1:
  36                         cth.s = 0
  37                 }
  38         }
  39
  40         cth.h.Write(buf[start:])
  41         return len(buf), nil
  42 }
  43
  44 func (cth *canonicalTextHash) Sum(in []byte) []byte {
  45         return cth.h.Sum(in)
  46 }
  47
  48 func (cth *canonicalTextHash) Reset() {
  49         cth.h.Reset()
  50         cth.s = 0
  51 }
  52
  53 func (cth *canonicalTextHash) Size() int {
  54         return cth.h.Size()
  55 }
  56
  57 func (cth *canonicalTextHash) BlockSize() int {
  58         return cth.h.BlockSize()
  59 }