diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/openpgp/armor')
-rw-r--r-- | vendor/golang.org/x/crypto/openpgp/armor/armor.go | 219 | ||||
-rw-r--r-- | vendor/golang.org/x/crypto/openpgp/armor/encode.go | 160 |
2 files changed, 379 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/openpgp/armor/armor.go b/vendor/golang.org/x/crypto/openpgp/armor/armor.go new file mode 100644 index 00000000..592d1864 --- /dev/null +++ b/vendor/golang.org/x/crypto/openpgp/armor/armor.go @@ -0,0 +1,219 @@ +// 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 implements OpenPGP ASCII Armor, see RFC 4880. OpenPGP Armor is +// very similar to PEM except that it has an additional CRC checksum. +package armor // import "golang.org/x/crypto/openpgp/armor" + +import ( + "bufio" + "bytes" + "encoding/base64" + "golang.org/x/crypto/openpgp/errors" + "io" +) + +// A Block represents an OpenPGP armored structure. +// +// The encoded form is: +// -----BEGIN Type----- +// Headers +// +// base64-encoded Bytes +// '=' base64 encoded checksum +// -----END Type----- +// where Headers is a possibly empty sequence of Key: Value lines. +// +// Since the armored data can be very large, this package presents a streaming +// interface. +type Block struct { + Type string // The type, taken from the preamble (i.e. "PGP SIGNATURE"). + Header map[string]string // Optional headers. + Body io.Reader // A Reader from which the contents can be read + lReader lineReader + oReader openpgpReader +} + +var ArmorCorrupt error = errors.StructuralError("armor invalid") + +const crc24Init = 0xb704ce +const crc24Poly = 0x1864cfb +const crc24Mask = 0xffffff + +// crc24 calculates the OpenPGP checksum as specified in RFC 4880, section 6.1 +func crc24(crc uint32, d []byte) uint32 { + for _, b := range d { + crc ^= uint32(b) << 16 + for i := 0; i < 8; i++ { + crc <<= 1 + if crc&0x1000000 != 0 { + crc ^= crc24Poly + } + } + } + return crc +} + +var armorStart = []byte("-----BEGIN ") +var armorEnd = []byte("-----END ") +var armorEndOfLine = []byte("-----") + +// lineReader wraps a line based reader. It watches for the end of an armor +// block and records the expected CRC value. +type lineReader struct { + in *bufio.Reader + buf []byte + eof bool + crc uint32 +} + +func (l *lineReader) Read(p []byte) (n int, err error) { + if l.eof { + return 0, io.EOF + } + + if len(l.buf) > 0 { + n = copy(p, l.buf) + l.buf = l.buf[n:] + return + } + + line, isPrefix, err := l.in.ReadLine() + if err != nil { + return + } + if isPrefix { + return 0, ArmorCorrupt + } + + if len(line) == 5 && line[0] == '=' { + // This is the checksum line + var expectedBytes [3]byte + var m int + m, err = base64.StdEncoding.Decode(expectedBytes[0:], line[1:]) + if m != 3 || err != nil { + return + } + l.crc = uint32(expectedBytes[0])<<16 | + uint32(expectedBytes[1])<<8 | + uint32(expectedBytes[2]) + + line, _, err = l.in.ReadLine() + if err != nil && err != io.EOF { + return + } + if !bytes.HasPrefix(line, armorEnd) { + return 0, ArmorCorrupt + } + + l.eof = true + return 0, io.EOF + } + + if len(line) > 96 { + return 0, ArmorCorrupt + } + + n = copy(p, line) + bytesToSave := len(line) - n + if bytesToSave > 0 { + if cap(l.buf) < bytesToSave { + l.buf = make([]byte, 0, bytesToSave) + } + l.buf = l.buf[0:bytesToSave] + copy(l.buf, line[n:]) + } + + return +} + +// openpgpReader passes Read calls to the underlying base64 decoder, but keeps +// a running CRC of the resulting data and checks the CRC against the value +// found by the lineReader at EOF. +type openpgpReader struct { + lReader *lineReader + b64Reader io.Reader + currentCRC uint32 +} + +func (r *openpgpReader) Read(p []byte) (n int, err error) { + n, err = r.b64Reader.Read(p) + r.currentCRC = crc24(r.currentCRC, p[:n]) + + if err == io.EOF { + if r.lReader.crc != uint32(r.currentCRC&crc24Mask) { + return 0, ArmorCorrupt + } + } + + return +} + +// Decode reads a PGP armored block from the given Reader. It will ignore +// leading garbage. If it doesn't find a block, it will return nil, io.EOF. The +// given Reader is not usable after calling this function: an arbitrary amount +// of data may have been read past the end of the block. +func Decode(in io.Reader) (p *Block, err error) { + r := bufio.NewReaderSize(in, 100) + var line []byte + ignoreNext := false + +TryNextBlock: + p = nil + + // Skip leading garbage + for { + ignoreThis := ignoreNext + line, ignoreNext, err = r.ReadLine() + if err != nil { + return + } + if ignoreNext || ignoreThis { + continue + } + line = bytes.TrimSpace(line) + if len(line) > len(armorStart)+len(armorEndOfLine) && bytes.HasPrefix(line, armorStart) { + break + } + } + + p = new(Block) + p.Type = string(line[len(armorStart) : len(line)-len(armorEndOfLine)]) + p.Header = make(map[string]string) + nextIsContinuation := false + var lastKey string + + // Read headers + for { + isContinuation := nextIsContinuation + line, nextIsContinuation, err = r.ReadLine() + if err != nil { + p = nil + return + } + if isContinuation { + p.Header[lastKey] += string(line) + continue + } + line = bytes.TrimSpace(line) + if len(line) == 0 { + break + } + + i := bytes.Index(line, []byte(": ")) + if i == -1 { + goto TryNextBlock + } + lastKey = string(line[:i]) + p.Header[lastKey] = string(line[i+2:]) + } + + p.lReader.in = r + p.oReader.currentCRC = crc24Init + p.oReader.lReader = &p.lReader + p.oReader.b64Reader = base64.NewDecoder(base64.StdEncoding, &p.lReader) + p.Body = &p.oReader + + return +} 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 00000000..6f07582c --- /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 +} |