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Diffstat (limited to 'vendor/golang.org/x/crypto/openpgp/armor/encode.go')
-rw-r--r--vendor/golang.org/x/crypto/openpgp/armor/encode.go160
1 files changed, 160 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/openpgp/armor/encode.go b/vendor/golang.org/x/crypto/openpgp/armor/encode.go
new file mode 100644
index 0000000..6f07582
--- /dev/null
+++ b/vendor/golang.org/x/crypto/openpgp/armor/encode.go
@@ -0,0 +1,160 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package armor
+
+import (
+ "encoding/base64"
+ "io"
+)
+
+var armorHeaderSep = []byte(": ")
+var blockEnd = []byte("\n=")
+var newline = []byte("\n")
+var armorEndOfLineOut = []byte("-----\n")
+
+// writeSlices writes its arguments to the given Writer.
+func writeSlices(out io.Writer, slices ...[]byte) (err error) {
+ for _, s := range slices {
+ _, err = out.Write(s)
+ if err != nil {
+ return err
+ }
+ }
+ return
+}
+
+// lineBreaker breaks data across several lines, all of the same byte length
+// (except possibly the last). Lines are broken with a single '\n'.
+type lineBreaker struct {
+ lineLength int
+ line []byte
+ used int
+ out io.Writer
+ haveWritten bool
+}
+
+func newLineBreaker(out io.Writer, lineLength int) *lineBreaker {
+ return &lineBreaker{
+ lineLength: lineLength,
+ line: make([]byte, lineLength),
+ used: 0,
+ out: out,
+ }
+}
+
+func (l *lineBreaker) Write(b []byte) (n int, err error) {
+ n = len(b)
+
+ if n == 0 {
+ return
+ }
+
+ if l.used == 0 && l.haveWritten {
+ _, err = l.out.Write([]byte{'\n'})
+ if err != nil {
+ return
+ }
+ }
+
+ if l.used+len(b) < l.lineLength {
+ l.used += copy(l.line[l.used:], b)
+ return
+ }
+
+ l.haveWritten = true
+ _, err = l.out.Write(l.line[0:l.used])
+ if err != nil {
+ return
+ }
+ excess := l.lineLength - l.used
+ l.used = 0
+
+ _, err = l.out.Write(b[0:excess])
+ if err != nil {
+ return
+ }
+
+ _, err = l.Write(b[excess:])
+ return
+}
+
+func (l *lineBreaker) Close() (err error) {
+ if l.used > 0 {
+ _, err = l.out.Write(l.line[0:l.used])
+ if err != nil {
+ return
+ }
+ }
+
+ return
+}
+
+// encoding keeps track of a running CRC24 over the data which has been written
+// to it and outputs a OpenPGP checksum when closed, followed by an armor
+// trailer.
+//
+// It's built into a stack of io.Writers:
+// encoding -> base64 encoder -> lineBreaker -> out
+type encoding struct {
+ out io.Writer
+ breaker *lineBreaker
+ b64 io.WriteCloser
+ crc uint32
+ blockType []byte
+}
+
+func (e *encoding) Write(data []byte) (n int, err error) {
+ e.crc = crc24(e.crc, data)
+ return e.b64.Write(data)
+}
+
+func (e *encoding) Close() (err error) {
+ err = e.b64.Close()
+ if err != nil {
+ return
+ }
+ e.breaker.Close()
+
+ var checksumBytes [3]byte
+ checksumBytes[0] = byte(e.crc >> 16)
+ checksumBytes[1] = byte(e.crc >> 8)
+ checksumBytes[2] = byte(e.crc)
+
+ var b64ChecksumBytes [4]byte
+ base64.StdEncoding.Encode(b64ChecksumBytes[:], checksumBytes[:])
+
+ return writeSlices(e.out, blockEnd, b64ChecksumBytes[:], newline, armorEnd, e.blockType, armorEndOfLine)
+}
+
+// Encode returns a WriteCloser which will encode the data written to it in
+// OpenPGP armor.
+func Encode(out io.Writer, blockType string, headers map[string]string) (w io.WriteCloser, err error) {
+ bType := []byte(blockType)
+ err = writeSlices(out, armorStart, bType, armorEndOfLineOut)
+ if err != nil {
+ return
+ }
+
+ for k, v := range headers {
+ err = writeSlices(out, []byte(k), armorHeaderSep, []byte(v), newline)
+ if err != nil {
+ return
+ }
+ }
+
+ _, err = out.Write(newline)
+ if err != nil {
+ return
+ }
+
+ e := &encoding{
+ out: out,
+ breaker: newLineBreaker(out, 64),
+ crc: crc24Init,
+ blockType: bType,
+ }
+ e.b64 = base64.NewEncoder(base64.StdEncoding, e.breaker)
+ return e, nil
+}