github.com/graybobo/golang.org-package-offline-cache@v0.0.0-20200626051047-6608995c132f/x/crypto/openpgp/packet/literal.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 packet
     6  
     7  import (
     8  	"encoding/binary"
     9  	"io"
    10  )
    11  
    12  // LiteralData represents an encrypted file. See RFC 4880, section 5.9.
    13  type LiteralData struct {
    14  	IsBinary bool
    15  	FileName string
    16  	Time     uint32 // Unix epoch time. Either creation time or modification time. 0 means undefined.
    17  	Body     io.Reader
    18  }
    19  
    20  // ForEyesOnly returns whether the contents of the LiteralData have been marked
    21  // as especially sensitive.
    22  func (l *LiteralData) ForEyesOnly() bool {
    23  	return l.FileName == "_CONSOLE"
    24  }
    25  
    26  func (l *LiteralData) parse(r io.Reader) (err error) {
    27  	var buf [256]byte
    28  
    29  	_, err = readFull(r, buf[:2])
    30  	if err != nil {
    31  		return
    32  	}
    33  
    34  	l.IsBinary = buf[0] == 'b'
    35  	fileNameLen := int(buf[1])
    36  
    37  	_, err = readFull(r, buf[:fileNameLen])
    38  	if err != nil {
    39  		return
    40  	}
    41  
    42  	l.FileName = string(buf[:fileNameLen])
    43  
    44  	_, err = readFull(r, buf[:4])
    45  	if err != nil {
    46  		return
    47  	}
    48  
    49  	l.Time = binary.BigEndian.Uint32(buf[:4])
    50  	l.Body = r
    51  	return
    52  }
    53  
    54  // SerializeLiteral serializes a literal data packet to w and returns a
    55  // WriteCloser to which the data itself can be written and which MUST be closed
    56  // on completion. The fileName is truncated to 255 bytes.
    57  func SerializeLiteral(w io.WriteCloser, isBinary bool, fileName string, time uint32) (plaintext io.WriteCloser, err error) {
    58  	var buf [4]byte
    59  	buf[0] = 't'
    60  	if isBinary {
    61  		buf[0] = 'b'
    62  	}
    63  	if len(fileName) > 255 {
    64  		fileName = fileName[:255]
    65  	}
    66  	buf[1] = byte(len(fileName))
    67  
    68  	inner, err := serializeStreamHeader(w, packetTypeLiteralData)
    69  	if err != nil {
    70  		return
    71  	}
    72  
    73  	_, err = inner.Write(buf[:2])
    74  	if err != nil {
    75  		return
    76  	}
    77  	_, err = inner.Write([]byte(fileName))
    78  	if err != nil {
    79  		return
    80  	}
    81  	binary.BigEndian.PutUint32(buf[:], time)
    82  	_, err = inner.Write(buf[:])
    83  	if err != nil {
    84  		return
    85  	}
    86  
    87  	plaintext = inner
    88  	return
    89  }