literal.go

Documentation: github.com/ProtonMail/go-crypto/openpgp/packet

     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  	Format   uint8
    15  	IsBinary bool
    16  	FileName string
    17  	Time     uint32 // Unix epoch time. Either creation time or modification time. 0 means undefined.
    18  	Body     io.Reader
    19  }
    20  
    21  // ForEyesOnly returns whether the contents of the LiteralData have been marked
    22  // as especially sensitive.
    23  func (l *LiteralData) ForEyesOnly() bool {
    24  	return l.FileName == "_CONSOLE"
    25  }
    26  
    27  func (l *LiteralData) parse(r io.Reader) (err error) {
    28  	var buf [256]byte
    29  
    30  	_, err = readFull(r, buf[:2])
    31  	if err != nil {
    32  		return
    33  	}
    34  
    35  	l.Format = buf[0]
    36  	l.IsBinary = l.Format == 'b'
    37  	fileNameLen := int(buf[1])
    38  
    39  	_, err = readFull(r, buf[:fileNameLen])
    40  	if err != nil {
    41  		return
    42  	}
    43  
    44  	l.FileName = string(buf[:fileNameLen])
    45  
    46  	_, err = readFull(r, buf[:4])
    47  	if err != nil {
    48  		return
    49  	}
    50  
    51  	l.Time = binary.BigEndian.Uint32(buf[:4])
    52  	l.Body = r
    53  	return
    54  }
    55  
    56  // SerializeLiteral serializes a literal data packet to w and returns a
    57  // WriteCloser to which the data itself can be written and which MUST be closed
    58  // on completion. The fileName is truncated to 255 bytes.
    59  func SerializeLiteral(w io.WriteCloser, isBinary bool, fileName string, time uint32) (plaintext io.WriteCloser, err error) {
    60  	var buf [4]byte
    61  	buf[0] = 't'
    62  	if isBinary {
    63  		buf[0] = 'b'
    64  	}
    65  	if len(fileName) > 255 {
    66  		fileName = fileName[:255]
    67  	}
    68  	buf[1] = byte(len(fileName))
    69  
    70  	inner, err := serializeStreamHeader(w, packetTypeLiteralData)
    71  	if err != nil {
    72  		return
    73  	}
    74  
    75  	_, err = inner.Write(buf[:2])
    76  	if err != nil {
    77  		return
    78  	}
    79  	_, err = inner.Write([]byte(fileName))
    80  	if err != nil {
    81  		return
    82  	}
    83  	binary.BigEndian.PutUint32(buf[:], time)
    84  	_, err = inner.Write(buf[:])
    85  	if err != nil {
    86  		return
    87  	}
    88  
    89  	plaintext = inner
    90  	return
    91  }
    92
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